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Review ArticleHeterogeneous Metal Catalysts for Oxidation Reactions
Md Eaqub Ali1 Md Motiar Rahman1 Shaheen M Sarkar2 and Sharifah Bee Abd Hamid1
1 Nanotechnology and Catalysis Research Centre (NanoCat) Universiti of Malaya 50603 Kuala Lumpur Malaysia2 Faculty of Industrial Sciences and Technology University Malaysia Pahang 26300 Gambang Kuantan Malaysia
Correspondence should be addressed to Md Eaqub Ali eaqubaligmailcom
Received 11 August 2014 Accepted 9 October 2014 Published 22 December 2014
Academic Editor Amir Kajbafvala
Copyright copy 2014 Md Eaqub Ali et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Oxidation reactions may be considered as the heart of chemical synthesis However the indiscriminate uses of harsh and corrosivechemicals in this endeavor are threating to the ecosystems public health and terrestrial aquatic and aerial flora and faunaHeterogeneous catalysts with various supports are brought to the spotlight because of their excellent capabilities to accelerate therate of chemical reactions with low costThey alsominimize the use of chemicals in industries and thus are friendly and green to theenvironment However heterogeneous oxidation catalysis are not comprehensively presented in literature In this short review weclearly depicted the current state of catalytic oxidation reactions in chemical industries with specific emphasis on heterogeneouscatalysts We outlined here both the synthesis and applications of important oxidation catalysts We believe it would serve as areference guide for the selection of oxidation catalysts for both industries and academics
1 Introduction
Oxidation reactions play a pivotal role in chemical industryfor the production of many crucial compounds [1] Forexample selective oxidation of alkyl substituted benzene pro-duces alcohol and ketones which have significant biologicaland mechanistic interest in modern organic synthesis [2]Ethylbenzene is a representative compound of various linearand phenyl-substituted alkanes and is a model substrate tostudy alkane oxidation reactions The oxidation productsof ethylbenzene include acetophenone and 1-phenylethanolwhich have been used as precursors for the synthesis of a widevariety of drugs such as hydrogel [3] optically active alcohols[2] hydrazones [4] benzalacetophenones (chalcones) [5]tear gas and resins [6]
In the past efforts were made for the oxidation of alkylsubstituted benzene to useful products such as benzylic andallylic ketones by adding stoichiometric amounts of strongoxidants such as chromium (IV) reagents permanganatestert-butyl hydroperoxide (TBHP) selenium oxide (SeO
2)
ruthenium (VIII) oxide hydrogen peroxide nitric acid andoxygen [7ndash9] However most of these chemicals are eithertoxic or corrosive to reactor wall unstable in atmosphericconditions nonspecific in actions which produce manyundesirable side products and that increases the purification
cost and environment pollutant [7ndash9] These traditionaltransformation schemes are also time consuming and cannotbe recycled [10]
The green chemistry approaches must meet health andenvironmental safeties and use very little chemicals reducingboth cost and time [11] Catalytic approaches might beconsidered as green since specific chemical transformationcould be achieved within very short time with the addition ofvery little catalysts significantly reducing production cost aswell as health and environmental risks [12 13] According tothe North American Catalysis Society approximately 35 ofglobal GDP rest on catalysts and the use of catalysts in indus-try are increasing 5 per year [14] Currently more than 60of chemical synthesis and 90 of chemical transformationsin chemical industries are using catalysts [15 16] In 2013the sales of catalysts were between 155 billion USD and theturnover in industries using catalyst was 14 trillion USD
Homogeneous catalyst has been extensively used in theoxidative process for the manufacturing of bulk as well asfine chemicals This is because of its efficiency in bringinghuge influences in chemical conversion via the same phasecatalysis reaction [17] In the recent time some transitionmetal ion complexes have shown high selectivity efficiency
Hindawi Publishing CorporationJournal of NanomaterialsVolume 2014 Article ID 192038 23 pageshttpdxdoiorg1011552014192038
2 Journal of Nanomaterials
Table 1 Major features advantages and disadvantages of the commonly used support materials
Supports materials Features Advantages Disadvantages References
Alumina
(1) Hardness(2) High melting point andhigh compression strength(3) Resistant to abrasionand chemical attack(4) High thermalconductivity
(1) Thermally stable(2) Randomly ordered(3) High surface area andpore volume(4) Well-ordered pore(5) Narrow pore size
(1) Difficult to control thehydrolysis rate ofaluminum precursors
[73]
Silica
(1) Tendency to form largenetworks(2) Found in nature andliving organisms(3) Hardness
(1) High efficiency(2) High selectivity(3) Highly stable(4) Mechanical strength
(1) Low compatibility(2) Formation ofaggregatesagglomerates
[74]
Zeolite(1) Microporous(2) Inertness(3) Excellent electronconductivity
(1) Highly effective(2) Less or no corrosion(3) No waste or disposalproblems(4) High thermo stability(5) Easy set-up ofcontinuous processes(6) Great adaptability topractically all types ofcatalysis
(1) Irreversible adsorptionor steric blockage of heavysecondary products(2) Impossibility of usingmicroporosity(3) Difficult to exploit theshape selectivity
[75 76]
Carbon(1) Nonmetallic(2) Tetravalent(3) Porous structure
(1) High mechanicalstrength(2) Large surface area(3) Excellent electronconductivity(4) Good elasticity(5) Thermal stability(6) Inertness
(1) High temperaturephysical activation(2) Expensive(3) Emission of greenhousegasses during pyrolysis
[77 78]
and reproducibility to catalyze the reaction under mild con-ditions The single catalytic entity in homogeneous catalystscan act as a single active site which can speed up reaction andreduce the reaction time [18] However homogeneous cat-alytic processes produce huge waste materials significantlydisrupting the environmental and ecological stability [19ndash21]One of the main disadvantages to the use of these types ofcatalysts is the ease of separating of the comparatively affluentcatalysts from the reaction mixtures at the end of reaction[9 19 22] Homogeneous catalysts also cause corrosion tothe industrial materials and some of them are deposited onthe reactor wall To get rid of these problems and minimizeenvironmental hazards the homogenous catalysts could beprepared by the dispersion of metal on an insoluble solidsupports via covalent anchoring to keep the metal on thesurface where catalysis reaction takes place [18 22]
Heterogeneous catalyst is considered to be a better choicefor the synthesis of commodity materials [23ndash25] Nowadayssilica carbon clay zeolite metal oxide polymers and othermesoporous materials are being used as inorganic solidsupports [26 27] Supported materials can be obtained ascomplexes with transition metals and Schiff base ligandsby heterogenization process [28] The application of sup-ported polymers in catalytic oxidation has gained muchattention because of their inertness and nontoxic nonvolatileand recyclable criteria [29] Among inorganic supports
the mesoporous materials have been proven to be idealcatalyst supports due to their three-dimensional open porenetwork structures high surface area and porosity highreusability and heat stability and uniform and interconnectedpores which offer a reliable and well-separated atmospherefor the deposition of dynamic components and interactivesurfaces between the catalysts and reactants [30ndash38] Varioussupport materials along with their major features are pre-sented in Table 1
Heterogeneous catalysts promote oxidation reactions viaattracting oxygen fromoxidants such as TBHP (tert-BuO
2H)
and HP (H2O2) [39 40] In the last decade TBHP has been
used as oxidant for various oxidation reactions such as alkylbenzene and benzyl alcohol oxidation In this review wedescribed heterogeneous catalysts their synthesis schemeson various supports and applications in selected oxidationreactions The comparative features of homogeneous andheterogeneous catalysts are presented in Figure 1
2 Heterogeneous Catalysts
In heterogeneous catalysis reaction the catalysts and reac-tants exist in different phases In reality the vast majority ofheterogeneous catalysts are solids and the vast majority ofreactants are either gases or liquids [14] A phase separationcatalysis reaction greatly helps in reactant product and
Journal of Nanomaterials 3
Disadvantages
Advantages
Major features
Homogeneous
Major features
Catalysts
Heterogeneous
Advantages
Disadvantages
(1) Difficult separation
(3) Huge waste materials (4) Product
(2) Reactor corrosion
(1) Dissolves in reaction medium hence all catalytic sites are available for reaction
(5) Complicated handling
(1) Nonselective to chiral catalysis
(3) Use as fixed beds
(1) Same phase (catalysts reactants and products)
(2) Co dissolved
(3) High selectivity
(4) Easy separation
(2) Reusable (1) Stable
(2) Difficult to study and hence reactionmechanisms are often unknown
(1) Different phases (catalysts reactants and products)
(2) Poor selectivity
(3) No solvent required
Figure 1 Special features advantages and disadvantages of homo- and heterogeneous catalysts
catalyst separation at the end of the reaction Heterogeneouscatalysts are also easier to prepare and handleThese catalystsconsist of fine nanosized powders supported on technicallyinert oxide substrates exhibiting all possible crystallographicfaces The catalyst is often a metal to which chemical andstructural promoters or poisons are added to enhance theefficiency andor the selectivity Currently heterogeneouscatalysis is dominating in industries for chemical trans-formation and energy generation Approximately 90 ofall industrial practices indulge in heterogeneous catalysisThe most recent applications of heterogeneous catalysts aresummarized in Table 2
3 Heterogeneous Metal Catalystsin Oxidation Reactions
Over the last few decades scientists have paid tremen-dous attention to heterogeneous catalysts to overcome the
limitations of their homogeneous counterparts to increaseproducts yields and minimize side reactions Herein wereported a summary of selected oxidation reactions catalyzedby supported metal catalysts
31 Conversion of Glucose to Gluconic Acid Recently theaerobic oxidation of glucose to gluconic acid (Figure 2)has gained much consideration because of its water-solublecleansing properties and application in food additives andbeverage bottle detergents [41] In the past the oxidation ofglucose was carried out via biochemical pathways which arecumbersome multistep process not recyclable and expen-sive [42] The development of catalytic route is probably analternative pathway for the large scale production of gluconicacid from glucose In 1970s researchers used to dope Ptor Pd onto some heavy metals such as bismuth Howeverseveral limitations such as instability poor selectivity andlow conversion rate were encountered with this procedure
4 Journal of Nanomaterials
Table2Re
cent
scenario
inheterogeneou
scatalysis
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2013
Fenano
catalyst
Immob
ilizatio
nEthylbenzenecyclohexeneand
benzylalcoho
loxidation
[18]
2013
AuA
l 2O3Au
CDeposition
-precipitatio
ncatio
nica
dsorption
Glucose
oxidation
[79]
2013
AuPtb
imetallic
nano
particles
mdashGlucose
oxidation
[80]
2013
Goldnano
particles
supp
ortedon
Mg(OH) 2nano
sheets
Colloidaldepo
sition
COoxidation
[81]
2013
AuTiO
2supp
ortedon
ferritics
tainles
sste
elmon
olith
sDire
ctanionice
xchange
COoxidation
[82]
2013
Nanop
orou
sgold
Electro
lytic
dissolution
COoxidation
[83]
2013
P123-stabilized
Au-Agalloy
Coredu
ction
Benzylalcoho
loxidatio
n[84]
2013
Alumina-supp
ortedgold-ruthenium
bimetallic
catalysts
Incipientw
etnessIm
pregnatio
nDeposition
Precipitatio
nCO
oxidation
[54]
2013
AuCuO
catalysts
Cop
recipitatio
nAlcoh
oloxidation
[85]
2013
Cerium
mod
ified
silver
Impregnatio
nAlkylarom
aticcompo
unds
[86]
2013
Pd-Aucatalyst
Deallo
ying
Methano
lelectrooxidation
[87]
2013
AuZnO
andAu
TiO
2catalysts
Colloidaldepo
sition
Methano
loxidatio
n[88]
2013
Microstructured
AuN
i-fiberc
atalyst
Incipientimpregnatin
gAlcoh
oloxidation
[89]
2013
Nanocrystallin
eAgandAu
-Agalloys
supp
ortedon
titania
Deposition
Precipitatio
nCO
oxidation
[90]
2013
Nanosized
Ausupp
ortedon
3-Dordered
mesop
orou
sMnO
2
Deposition
Precipitatio
nOxidatio
nof
carbon
mon
oxidebenzeneandtoluene
[91]
2013
AuFeO119909
Cop
recipitatio
nCO
oxidation
[92]
2013
Nanosized
ruthenium
particlesd
ecorated
carbon
nano
fibers
Solgel
p-Cy
meneo
xidatio
n[93]
2012
AuC
Incipientw
etness
impregnatio
nGlucose
oxidation
[94]
2012
CeA
lPO-5
molecular
sieves
mdashDiphenylm
ethane
oxidation
[10]
2012
Nanosized
gold
onSiO
2Stob
erCy
clohexene
andD-glucose
oxidation
[95]
2012
AuSiO
2Disp
ersio
nSilaneso
xidatio
n[47]
2012
Nanogold-m
esop
orou
ssilica
mdashCO
oxidation
benzylalcoho
loxidatio
n[96]
2012
Nanosized
gold
Disp
ersio
nAlkylbenzeneo
xidatio
n[40]
2012
AgSB
A-15
Impregnatio
nAlkylsubstituted
arom
atics
[35]
2012
Bimetallic
Au-PdMgO
Sol-immob
ilizatio
n(SI)and
adsorptio
n-redu
ction(A
R)Be
nzylalcoho
loxidatio
n[97]
Journal of Nanomaterials 5
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2012
InverseF
e 2O
3Au
(111)m
odelcatalysts
mdashCO
oxidation
[98]
2012
Silica-supp
ortedAu
-Cualloy
mdashAlcoh
oloxidation
[99]
2012
Goldnano
particlessup
ported
onMgO
Deposition
-precipitatio
nAlcoh
oloxidation
[100]
2012
Silica-supp
ortedAu
-CuO119909
Oxidativ
edeallo
ying
Ethano
loxidatio
n[101]
2011
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
oxidation
[102]
2011
Au-PdC
Impregnatio
nGlyoxalandglucoseo
xidatio
n[103]
2011
Pd-Tes
uppo
rted
catalysts
Repeated
impregnatio
nGlucose
oxidation
[104]
2011
Goldnano
particlessup
ported
onfunctio
nalized
mesop
orou
ssilica
One-pot
Synthesis
Cyclo
hexane
oxidation
[105]
2011
Silicas
uppo
rted
cobalt(II)salencomplex
Immob
ilizatio
nAlkylbenzeneo
xidatio
n[70]
2011
Goldnano
wire
smdash
Oxidatio
nof
benzyliccompo
unds
[106]
2011
Cu32[PM
o 12O
40]SiO
2Incipientw
etness
impregnatio
nBe
nzylicalcoho
l[107]
2010
Goldnano
particlesd
epositedon
cellu
lose
Deposition
-reductio
ngrinding
metho
dGlucose
oxidation
[41]
2010
Metallopo
rphyrin
boun
dto
silica
Immob
ilizatio
nEthylbenzene
oxidation
[68]
2010
Hydroph
obized
palladium
Vapo
rdeposition
Glucose
oxidation
[108]
2010
Supp
ortedgold
catalysts
Colloidalgold
depo
sition
COoxidation
[109]
2010
AuH
MScatalysts
Impregnatio
nanddirect
synthesis
Benzylalcoho
loxidatio
n[63]
2010
Mob
ilizedgold
nano
particles
Goldsol
Second
aryalcoho
lsoxidation
[67]
2010
Mesop
orou
sCo 3O
4andAu
Co 3O
4catalysts
Nanocastin
gEthylene
oxidation
[110]
2010
Metal-organicfram
eworksupp
ortedgold
nano
particles
Colloidaldepo
sition
Alcoh
oloxidation
[111]
2010
PtA
l 2O3
Impregnatio
nHeavy
hydrocarbo
nsoxidation
[112]
2009
AuTiO
2Deposition
-precipitatio
nAlcoh
oloxidation
[113]
2009
Co(Ac
O) 2M
n(Ac
O) 2
Dire
ctcond
ensatio
np-xylene
oxidation
[114]
6 Journal of Nanomaterials
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2009
Nickelsub
stitutedcopp
erchromite
spinels
Cop
recipitatio
nAlkylsubstituted
benzeneo
xidatio
n[9]
2007
Goldcatalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[115]
2007
MCM
-48molecular
sieve
mod
ified
with
SnCl
2Po
st-synthesis
mod
ificatio
nAlcoh
oloxidation
[65]
2007
CuO-im
pregnatedmesop
orou
ssilica
Impregnatio
nBe
nzeneo
xidatio
n[116]
2006
Supp
ortedgold
catalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[117]
2006
Au-C
uOA
l 2O3PtA
l 2O3catalysts
Deposition
-precipitatio
nim
pregnatio
nProp
enea
ndprop
aneo
xidatio
n[118]
2006
Manganese
containing
mesop
orou
sMCM
-41and
Al-M
CM-41
molecular
sieves
Impregnatio
np-iso
prop
yltolueneo
xidatio
n[119]
2005
Goldcatalysts
mdashAlcoh
oloxidation
[120]
2005
AuC
Immob
ilizatio
nGlucose
oxidation
Alcoh
oloxidation
[64]
2005
Goldim
mob
ilizedmesop
orou
ssilica
Immob
ilizatio
nCy
clohexane
oxidation
[121]
2005
Nitrou
soxide
over
MFI
zeolites
Hydrothermal
Benzeneo
xidatio
n[122]
2005
CoA
PO-5
molecular
sieves
Hydrothermal
Cyclo
hexane
oxidation
[123]
2004
Carbon
-sup
ported
gold
Goldsol
Glucose
oxidation
[124]
2004
Mn-containing
MCM
-41
Impregnatio
nEthylbenzene
oxidation
[72]
2003
CoO119909C
eO2
Cop
recipitaion
Carbon
mon
oxideo
xidatio
n[125]
2002
Goldcatalysts
Immob
ilizatio
nGlucose
oxidation
[126]
2002
Mn(Salen)MCM
-41
mdashOlefin
sepo
xidatio
n[127]
2002
NanostructuredCu
O119909C
eO2
Gas-con
densation
Carbon
mon
oxideo
xidatio
n[128]
2002
Nano-Au
Catalysts
mdashCa
rbon
mon
oxideo
xidatio
n[55]
2001
AuTiO
2Au
TiO
2SiO
2Deposition
-precipitatio
nProp
enee
poxidatio
n[129]
2000
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
yleneo
xidatio
n[130]
1999
Golddispersedon
TS1and
other
titanium-con
tainingsupp
orts
Disp
ersio
nProp
enee
poxidatio
n[131]
1998
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
ylenee
poxidatio
n[61]
1996
Heterop
olycatalysts
containing
Ru(III)
andRh
(III)p
articles
mdashAlkaneo
xidatio
n[132]
1996
Goldsupp
ortedon
ZnOandTiO
2Cop
recipitatio
namp
Deposition
-precipitatio
nCa
rbon
mon
oxideo
xidatio
n[133]
1996
Au-TiO
2Incipientw
etness
impregnatio
nCa
rbon
mon
oxideo
xidatio
n[134]
1995
Bism
uthprom
oted
palladium
catalysts
Ionexchange
Glucose
oxidation
[42]
Journal of Nanomaterials 7
HO HO
OOH
OHOH
OH OH
OHOH
OH
OH O
Glucose Gluconic acid
Catalysts
Figure 2 Conversion of glucose to gluconic acid
Si
ClCl Cl
H
trimethyl(phenyl)silane Tetramethylsilane Trichlorosilane
Si CH3
CH3
CH3
Si CH3
CH3
CH3
H3C
Scheme 1
H OH
Dimethylphenylsilane Dimethylphenylsilane
THF RTSi Si
CH3
CH3 CH3
CH3
+ H2O + H2
AuSiO2
Scheme 2
without any supporting materials [42] On the other handbismuth on palladium or PtPd on carbon supports demon-strated high selectivity and stability and excellent conversionrate overcoming the limitations of the heavy metal supportsSome features such as catalyst type and the role of bismuthsupport are still a disputed issue [42]
Prati and Rossi (1997) [43] studied the oxidation of12-diols and found excellent selectivity with gold catalystover platinum and palladium catalysts The gold catalystshowed unusual selectivity in the oxidation of alcohol to itscorresponding carboxylates whereas Pd or Pt showed lowerselectivity to oxidize ethane-12-diol From this observationthey also concluded that Au is less sensitive to overoxidationandor self-poisoning than Pd or Pt Gold clusters andnanoparticles (NPs) deposited on the metal oxide surfacesuch as Al
2O3and ZrO
2demonstrated unexpected catalytic
activity in the oxidation of glucose with better turnover fre-quency (TOF reaction rate per Au atom surface) In additionto carbon andmetal oxide supports some inorganic polymerssuch as silica could be used as catalytic supports for smallAu nanoparticles (gt10 nm in diameter) [43] The catalyticeffect of Au nanoparticles (25 nm) held by polymer gelwas demonstrated by Ishida et al [44] Polymer supportedAuNPs exhibited higher catalytic performance than AuC inthe oxidation of primary alcohols such as benzyl alcohol tobenzaldehyde in absence of base [45] The catalytic activityof various catalysts for glucose oxidation is summarized inTable 3
32 Selective Oxidation of Silanes to Silanols Silane is aninorganic compound having the silicon atom with chemical
formula SiH4 It is a colorless flammable gas with a sharp
and repulsive smell somewhat similar to that of acetic acidSilane has interest as a precursor of silicon metal Silanemay also be referred to many compounds containing sili-con such as trichlorosilane (SiHCl
3) trimethyl(phenyl)silane
(PhSi(CH3)3) and tetramethylsilane (Si(CH
3)4) (Scheme 1)
The oxidation of silane to corresponding silanols (asfor example dimethylphenylsilane to dimethylphenylsilanolScheme 2) is a key reaction to manufacture building blocksfor the synthesis of silica based polymers [46] and nucle-ophilic couplers in organic synthesis In the past silanolssynthesis was often carried out by stoichiometric oxidationof organosilanes hydrolysis of halosilanes or alkali treat-ment of siloxanes which incurred environmental hazards Incontrast the catalytic oxidation of silanes with water is anecofriendly process since it produces silanols with high selec-tivity producing only hydrogen as a by-product Supportedgold nanoparticles have shown higher catalytic activity andselectivity on silane oxidation over other transition metalcatalysts [47] Mitsudome et al [48] oxidized aliphatic silanesto silanols using hydroxyapatite supported AuNPs in waterat 80∘C Nanoporous gold also showed high reactivity andselectivity towards silanes in acetone at room temperature[49]
Recently John et al [50] have synthesized carbon nano-tube-supported gold nanoparticles which showed turnoverfrequency (TOF) of 18000 hminus1 for silane oxidation in tetrahy-drofuran (THF) at room temperature However the prepa-ration of Au CNT (carbon nanotube) hybrids involved amultistep layer-by-layer assembly which needed expensivereagents which have limited its practicability Li et al [47]
8 Journal of Nanomaterials
Table3Oxidatio
nof
glucoseb
yvario
uscatalysts
Nam
eofcatalysts
Preparationmetho
dRe
actio
ncond
ition
Mainprod
uct
Selectivity
()Re
ferences
SubstrateOxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)
pHSolvent
Goldnano
particleso
ncellu
lose
Deposition
-redu
ction
O2
mdash60
95Water
Gluconica
cid
mdash[41]
AuA
l 2O3
Deposition
-precipitatio
nO
27
6090
Water
Gluconica
cid
97[79]
AuC
Catio
nica
dsorption
O2
760
90Water
Gluconica
cid
97[79]
Au-PdC
Impregnatio
nO
220
5092
5mdash
Gluconica
cid
mdash[103]
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
H2O
240
90mdash
Sodium
D-gluconate
99[102]
AuC
Goldsol
mdash30
5095
mdashGluconica
cid
45[124]
Nanosized
AuSiO
2Stob
erH
2O2
2430
92Water
Gluconica
cid
80[95]
Pb-TeSiO
2Re
peated
impregnatio
nO
215
6090
mdashGluconica
cid
884
[104]
AuPtb
imetallic
nano
particle
Vacuum
drying
O2
260
95mdash
Gluconica
cid
mdash[80]
Journal of Nanomaterials 9
Table 4 Comparison of supported gold catalysts for the oxidation of triethylsilane [47]
Catalysts Reaction condition Conversion rate () Yield ()Substrate Solvent Reaction temperature Time (min) Ausubstrate (mol)
AuSiO2
Triethylsilane
Water 25∘C 3 04 99 99AuTiO2 Water 25∘C 3 04 81 81AuFe2O3 Water 25∘C 3 04 36 36AuZnO Water 25∘C 3 04 89 89AuCeO2 Water 25∘C 3 04 98 98
Catalyst
Decomposition
H2 + O2 H2O2
2H2O2
H2O + 12O2
Hydrogenation H2
Scheme 3 Hydrogen peroxide formation hydrogenation and decomposition
prepared silica supported gold catalysts for the selectiveoxidation of silanes However they observed that silicasupported gold catalysts aremore active than reducible oxides(TiO2 Fe2O3 CeO
2 etc) supported AuNPs Highly dis-
persed silica supported gold catalysts override the reducibleoxides supported AuNPs due to superior adsorption of silanesubstrate on silica support Surprisingly for the oxidationof dimethylphenylsilane in THF at room temperature theAuSiO
2catalyst afforded a TOF of 59400 hminus1 which is the
highest TOF reported to dateThe other oxide supported gold catalysts such as
AuTiO2 AuZnO and AuFe
2O3
were less active thanAuSiO
2 and they afforded a maximum conversion of 90
However the activity of AuCeO2catalyst was very similar to
the AuSiO2catalyst (Table 4)
33 Oxidation of Hydrogen to Hydrogen Peroxide (H2O2)
H2O2is an essential chemical which has long been used
mainly as strong oxidant in various oxidative reactions andbleaching agent as well as a disinfectant It is a green oxidantsince its sole by-product is water In the current decades alot of attention has been paid to the green catalysts and greenchemicals to ensure safety issues in health and environmentIndustries have been using supported Pd catalysts for morethan 90 years for the direct synthesis of H
2O2from H
2and
O2 However the synthesized H
2O2is unstable and under-
goes low-temperature decomposition or hydrogenation towater (Scheme 3) [51] Recently Edwards et al [52] usedAu-catalysts synthesized via coprecipitation or deposition-precipitation method and found very low H
2O2conversion
rateThey also observed that the addition of Au to Pd catalystsby impregnation enhances H
2O2formation They compared
five different catalyst supports namely Al2O3 Fe2O3 TiO2
SiO2
and carbon and found the high conversion withcarbon-supported Au-Pd (Au-PdC)
In 2010 Song et al [53] observed that KMnO4treated
activated carbon in an acidic solution enhances H2O2pro-
duction (78) from hydroxylamine due to the creation ofsurface active quinoid species during oxidation Structure
and surface analyses revealed that KMnO4treatment pro-
duced more phenolic but less carboxylic groups on theactivated carbon under acidic condition confirming thecrucial role of the quinoid groups It was also proposed thatthe quinoid groups served as electron acceptors and redoxmediators in the formation of H
2O2[53]
34 Carbon Monoxide (CO) Oxidation In the last decadeCOoxidation has become an important research area becauseof its involvement in a number of processes such asmethanolsynthesis water gas shift reaction carbon dioxide lasersand automotive exhaust controls [54] Carbon monoxide isa lethal gas for animal life and toxic to the environment[55] The oxidation of CO is a difficult process and hencea highly active oxidation catalyst is required for its efficientremoval from the environment [55] In the past the gold wasconsidered to be inert for CO oxidation [56]
However Haruta et al [57] demonstrated that highlydispersed gold prepared on various metal oxide supportsby coprecipitation and deposition-precipitation methods ishighly active in CO oxidation even below 0∘C temperatureThey found that catalytic performance significantly dependson the catalysts preparation methods and the highest activitywas demonstrated by TiO
2supported gold or platinum
catalysts prepared by deposition-precipitation (DP)The goldcatalysts prepared by photodeposition (PD) and impregna-tion (IMP) methods were less active than those preparedby deposition-precipitation This is because the catalystsprepared by DP method contain higher loading of Au(gt2wt) on smaller particles and are with better dispersionCollectively these features enable the catalyst to show higheractivity oxidizingsim100ofCOat temperatures belowminus20∘CIn 1997 Yuan et al [58] synthesized highly active goldcatalysts for CO oxidation simply by grafting Au-phosphinecomplexes (AuL
3NO3or Au
9L8(NO3)3 L = PPh
3) onto
precipitated Ti(OH)4surfaces This Au-phosphine-Ti(OH)
4
complex was active even below the 0∘C Apart from this Na+ions positively andClminus ions negatively affect the Au-catalyzed
10 Journal of Nanomaterials
C O
OH
C
O
O
O
H
O2
Mx+Mx+
AuIIIAuIIIAu0
O2minus
Figure 3 Plausible mechanism for CO oxidation on oxide supported gold catalyst On the left a CO molecule is chemisorbed onto a lowcoordination number gold atom (yellow sphere) and a hydroxyl ion is moved from the oxide support (pink sphere) to an Au (III) ioncreating an anion vacancy On the right they have reacted to form a carboxylate group and an oxygen molecule occupies the anion vacancyas O2minus (white sphere) This then oxidizes the carboxylate group by abstracting a hydrogen atom forming carbon dioxide and the resultinghydroperoxide ionHO
2
minus then further oxidizes carboxylate species to form another carbon dioxide restoring two hydroxyl ions to the supportsurface completing the catalytic cycle (Adapted with permission from Springer) [145]
O
Catalysts
Propene epoxide
Polyether polyols (66) Propene glycols (30) Propene glycols ether (4)
Polyurethanes or foam Polyesters Solvents
CH3CH=CH2 + O2 + H2CH3CH2ndashCH2 + H2O
Scheme 4 Synthetic products from propene epoxidation reaction
CO oxidation Figure 3 represents the initial stages of COoxidation at the edge of an active gold particle
35 Epoxidation of Propene The oxidation of propene toepoxide is an important reaction for the synthesis of variousindustrial chemicals such as polyether polyols (precursorof polyurethane or foams) propene glycol and propeneglycol ethers (Scheme 4) [59] In the past chlorohydrin andhydroperoxide mediated processes were used for the syn-thesis of propene epoxide Chlorohydrin process producesenvironmentally hazardous chlorinated by-products and thehydroperoxide process is much expensive and producesstyrene and tert-butyl alcohol as by-products Silver catalystswere used in this reaction but poor selectivity and turnoverwere observed [60] However titania supported gold effi-ciently catalyzed the epoxidation reaction at 30ndash120∘C withmore than 90 selectivity in the presence of hydrogen [61]
36 Oxidation of Alcohol The oxidation of alcohols to itscorresponding aldehydes or ketones is a crucial reaction inorganic synthesis Ketones specially acetone are widely usedin the production of various organic as well as fine chemicals[62] Traditional chemical routes use stoichiometric chem-icals such as chromium (VI) reagents dimethyl sulfoxidepermanganates periodates or N-chlorosuccinimide whichare expensive and hazardous Several homogeneous catalystssuch as Pd Cu and Ru are found to selectively catalyzealcohol oxidation However homogeneous catalysis requireshigh pressure oxygen andor organic solvent incurring costand environmental burdens [63] The present ecologicaldeterioration has forced researchers to look for novel andenvironmentally friendly catalytic schemes for the oxidationof alcohol Prati and Porta [64] demonstrated that AuCcatalyst shows higher selectivity toward aldehyde in the oxi-dation of primary alcohols Subsequently Endud and Wong[65] synthesized porous SiSn bimetallic catalyst through
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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International Journal of
Biomaterials
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MaterialsJournal of
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Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
2 Journal of Nanomaterials
Table 1 Major features advantages and disadvantages of the commonly used support materials
Supports materials Features Advantages Disadvantages References
Alumina
(1) Hardness(2) High melting point andhigh compression strength(3) Resistant to abrasionand chemical attack(4) High thermalconductivity
(1) Thermally stable(2) Randomly ordered(3) High surface area andpore volume(4) Well-ordered pore(5) Narrow pore size
(1) Difficult to control thehydrolysis rate ofaluminum precursors
[73]
Silica
(1) Tendency to form largenetworks(2) Found in nature andliving organisms(3) Hardness
(1) High efficiency(2) High selectivity(3) Highly stable(4) Mechanical strength
(1) Low compatibility(2) Formation ofaggregatesagglomerates
[74]
Zeolite(1) Microporous(2) Inertness(3) Excellent electronconductivity
(1) Highly effective(2) Less or no corrosion(3) No waste or disposalproblems(4) High thermo stability(5) Easy set-up ofcontinuous processes(6) Great adaptability topractically all types ofcatalysis
(1) Irreversible adsorptionor steric blockage of heavysecondary products(2) Impossibility of usingmicroporosity(3) Difficult to exploit theshape selectivity
[75 76]
Carbon(1) Nonmetallic(2) Tetravalent(3) Porous structure
(1) High mechanicalstrength(2) Large surface area(3) Excellent electronconductivity(4) Good elasticity(5) Thermal stability(6) Inertness
(1) High temperaturephysical activation(2) Expensive(3) Emission of greenhousegasses during pyrolysis
[77 78]
and reproducibility to catalyze the reaction under mild con-ditions The single catalytic entity in homogeneous catalystscan act as a single active site which can speed up reaction andreduce the reaction time [18] However homogeneous cat-alytic processes produce huge waste materials significantlydisrupting the environmental and ecological stability [19ndash21]One of the main disadvantages to the use of these types ofcatalysts is the ease of separating of the comparatively affluentcatalysts from the reaction mixtures at the end of reaction[9 19 22] Homogeneous catalysts also cause corrosion tothe industrial materials and some of them are deposited onthe reactor wall To get rid of these problems and minimizeenvironmental hazards the homogenous catalysts could beprepared by the dispersion of metal on an insoluble solidsupports via covalent anchoring to keep the metal on thesurface where catalysis reaction takes place [18 22]
Heterogeneous catalyst is considered to be a better choicefor the synthesis of commodity materials [23ndash25] Nowadayssilica carbon clay zeolite metal oxide polymers and othermesoporous materials are being used as inorganic solidsupports [26 27] Supported materials can be obtained ascomplexes with transition metals and Schiff base ligandsby heterogenization process [28] The application of sup-ported polymers in catalytic oxidation has gained muchattention because of their inertness and nontoxic nonvolatileand recyclable criteria [29] Among inorganic supports
the mesoporous materials have been proven to be idealcatalyst supports due to their three-dimensional open porenetwork structures high surface area and porosity highreusability and heat stability and uniform and interconnectedpores which offer a reliable and well-separated atmospherefor the deposition of dynamic components and interactivesurfaces between the catalysts and reactants [30ndash38] Varioussupport materials along with their major features are pre-sented in Table 1
Heterogeneous catalysts promote oxidation reactions viaattracting oxygen fromoxidants such as TBHP (tert-BuO
2H)
and HP (H2O2) [39 40] In the last decade TBHP has been
used as oxidant for various oxidation reactions such as alkylbenzene and benzyl alcohol oxidation In this review wedescribed heterogeneous catalysts their synthesis schemeson various supports and applications in selected oxidationreactions The comparative features of homogeneous andheterogeneous catalysts are presented in Figure 1
2 Heterogeneous Catalysts
In heterogeneous catalysis reaction the catalysts and reac-tants exist in different phases In reality the vast majority ofheterogeneous catalysts are solids and the vast majority ofreactants are either gases or liquids [14] A phase separationcatalysis reaction greatly helps in reactant product and
Journal of Nanomaterials 3
Disadvantages
Advantages
Major features
Homogeneous
Major features
Catalysts
Heterogeneous
Advantages
Disadvantages
(1) Difficult separation
(3) Huge waste materials (4) Product
(2) Reactor corrosion
(1) Dissolves in reaction medium hence all catalytic sites are available for reaction
(5) Complicated handling
(1) Nonselective to chiral catalysis
(3) Use as fixed beds
(1) Same phase (catalysts reactants and products)
(2) Co dissolved
(3) High selectivity
(4) Easy separation
(2) Reusable (1) Stable
(2) Difficult to study and hence reactionmechanisms are often unknown
(1) Different phases (catalysts reactants and products)
(2) Poor selectivity
(3) No solvent required
Figure 1 Special features advantages and disadvantages of homo- and heterogeneous catalysts
catalyst separation at the end of the reaction Heterogeneouscatalysts are also easier to prepare and handleThese catalystsconsist of fine nanosized powders supported on technicallyinert oxide substrates exhibiting all possible crystallographicfaces The catalyst is often a metal to which chemical andstructural promoters or poisons are added to enhance theefficiency andor the selectivity Currently heterogeneouscatalysis is dominating in industries for chemical trans-formation and energy generation Approximately 90 ofall industrial practices indulge in heterogeneous catalysisThe most recent applications of heterogeneous catalysts aresummarized in Table 2
3 Heterogeneous Metal Catalystsin Oxidation Reactions
Over the last few decades scientists have paid tremen-dous attention to heterogeneous catalysts to overcome the
limitations of their homogeneous counterparts to increaseproducts yields and minimize side reactions Herein wereported a summary of selected oxidation reactions catalyzedby supported metal catalysts
31 Conversion of Glucose to Gluconic Acid Recently theaerobic oxidation of glucose to gluconic acid (Figure 2)has gained much consideration because of its water-solublecleansing properties and application in food additives andbeverage bottle detergents [41] In the past the oxidation ofglucose was carried out via biochemical pathways which arecumbersome multistep process not recyclable and expen-sive [42] The development of catalytic route is probably analternative pathway for the large scale production of gluconicacid from glucose In 1970s researchers used to dope Ptor Pd onto some heavy metals such as bismuth Howeverseveral limitations such as instability poor selectivity andlow conversion rate were encountered with this procedure
4 Journal of Nanomaterials
Table2Re
cent
scenario
inheterogeneou
scatalysis
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2013
Fenano
catalyst
Immob
ilizatio
nEthylbenzenecyclohexeneand
benzylalcoho
loxidation
[18]
2013
AuA
l 2O3Au
CDeposition
-precipitatio
ncatio
nica
dsorption
Glucose
oxidation
[79]
2013
AuPtb
imetallic
nano
particles
mdashGlucose
oxidation
[80]
2013
Goldnano
particles
supp
ortedon
Mg(OH) 2nano
sheets
Colloidaldepo
sition
COoxidation
[81]
2013
AuTiO
2supp
ortedon
ferritics
tainles
sste
elmon
olith
sDire
ctanionice
xchange
COoxidation
[82]
2013
Nanop
orou
sgold
Electro
lytic
dissolution
COoxidation
[83]
2013
P123-stabilized
Au-Agalloy
Coredu
ction
Benzylalcoho
loxidatio
n[84]
2013
Alumina-supp
ortedgold-ruthenium
bimetallic
catalysts
Incipientw
etnessIm
pregnatio
nDeposition
Precipitatio
nCO
oxidation
[54]
2013
AuCuO
catalysts
Cop
recipitatio
nAlcoh
oloxidation
[85]
2013
Cerium
mod
ified
silver
Impregnatio
nAlkylarom
aticcompo
unds
[86]
2013
Pd-Aucatalyst
Deallo
ying
Methano
lelectrooxidation
[87]
2013
AuZnO
andAu
TiO
2catalysts
Colloidaldepo
sition
Methano
loxidatio
n[88]
2013
Microstructured
AuN
i-fiberc
atalyst
Incipientimpregnatin
gAlcoh
oloxidation
[89]
2013
Nanocrystallin
eAgandAu
-Agalloys
supp
ortedon
titania
Deposition
Precipitatio
nCO
oxidation
[90]
2013
Nanosized
Ausupp
ortedon
3-Dordered
mesop
orou
sMnO
2
Deposition
Precipitatio
nOxidatio
nof
carbon
mon
oxidebenzeneandtoluene
[91]
2013
AuFeO119909
Cop
recipitatio
nCO
oxidation
[92]
2013
Nanosized
ruthenium
particlesd
ecorated
carbon
nano
fibers
Solgel
p-Cy
meneo
xidatio
n[93]
2012
AuC
Incipientw
etness
impregnatio
nGlucose
oxidation
[94]
2012
CeA
lPO-5
molecular
sieves
mdashDiphenylm
ethane
oxidation
[10]
2012
Nanosized
gold
onSiO
2Stob
erCy
clohexene
andD-glucose
oxidation
[95]
2012
AuSiO
2Disp
ersio
nSilaneso
xidatio
n[47]
2012
Nanogold-m
esop
orou
ssilica
mdashCO
oxidation
benzylalcoho
loxidatio
n[96]
2012
Nanosized
gold
Disp
ersio
nAlkylbenzeneo
xidatio
n[40]
2012
AgSB
A-15
Impregnatio
nAlkylsubstituted
arom
atics
[35]
2012
Bimetallic
Au-PdMgO
Sol-immob
ilizatio
n(SI)and
adsorptio
n-redu
ction(A
R)Be
nzylalcoho
loxidatio
n[97]
Journal of Nanomaterials 5
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2012
InverseF
e 2O
3Au
(111)m
odelcatalysts
mdashCO
oxidation
[98]
2012
Silica-supp
ortedAu
-Cualloy
mdashAlcoh
oloxidation
[99]
2012
Goldnano
particlessup
ported
onMgO
Deposition
-precipitatio
nAlcoh
oloxidation
[100]
2012
Silica-supp
ortedAu
-CuO119909
Oxidativ
edeallo
ying
Ethano
loxidatio
n[101]
2011
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
oxidation
[102]
2011
Au-PdC
Impregnatio
nGlyoxalandglucoseo
xidatio
n[103]
2011
Pd-Tes
uppo
rted
catalysts
Repeated
impregnatio
nGlucose
oxidation
[104]
2011
Goldnano
particlessup
ported
onfunctio
nalized
mesop
orou
ssilica
One-pot
Synthesis
Cyclo
hexane
oxidation
[105]
2011
Silicas
uppo
rted
cobalt(II)salencomplex
Immob
ilizatio
nAlkylbenzeneo
xidatio
n[70]
2011
Goldnano
wire
smdash
Oxidatio
nof
benzyliccompo
unds
[106]
2011
Cu32[PM
o 12O
40]SiO
2Incipientw
etness
impregnatio
nBe
nzylicalcoho
l[107]
2010
Goldnano
particlesd
epositedon
cellu
lose
Deposition
-reductio
ngrinding
metho
dGlucose
oxidation
[41]
2010
Metallopo
rphyrin
boun
dto
silica
Immob
ilizatio
nEthylbenzene
oxidation
[68]
2010
Hydroph
obized
palladium
Vapo
rdeposition
Glucose
oxidation
[108]
2010
Supp
ortedgold
catalysts
Colloidalgold
depo
sition
COoxidation
[109]
2010
AuH
MScatalysts
Impregnatio
nanddirect
synthesis
Benzylalcoho
loxidatio
n[63]
2010
Mob
ilizedgold
nano
particles
Goldsol
Second
aryalcoho
lsoxidation
[67]
2010
Mesop
orou
sCo 3O
4andAu
Co 3O
4catalysts
Nanocastin
gEthylene
oxidation
[110]
2010
Metal-organicfram
eworksupp
ortedgold
nano
particles
Colloidaldepo
sition
Alcoh
oloxidation
[111]
2010
PtA
l 2O3
Impregnatio
nHeavy
hydrocarbo
nsoxidation
[112]
2009
AuTiO
2Deposition
-precipitatio
nAlcoh
oloxidation
[113]
2009
Co(Ac
O) 2M
n(Ac
O) 2
Dire
ctcond
ensatio
np-xylene
oxidation
[114]
6 Journal of Nanomaterials
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2009
Nickelsub
stitutedcopp
erchromite
spinels
Cop
recipitatio
nAlkylsubstituted
benzeneo
xidatio
n[9]
2007
Goldcatalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[115]
2007
MCM
-48molecular
sieve
mod
ified
with
SnCl
2Po
st-synthesis
mod
ificatio
nAlcoh
oloxidation
[65]
2007
CuO-im
pregnatedmesop
orou
ssilica
Impregnatio
nBe
nzeneo
xidatio
n[116]
2006
Supp
ortedgold
catalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[117]
2006
Au-C
uOA
l 2O3PtA
l 2O3catalysts
Deposition
-precipitatio
nim
pregnatio
nProp
enea
ndprop
aneo
xidatio
n[118]
2006
Manganese
containing
mesop
orou
sMCM
-41and
Al-M
CM-41
molecular
sieves
Impregnatio
np-iso
prop
yltolueneo
xidatio
n[119]
2005
Goldcatalysts
mdashAlcoh
oloxidation
[120]
2005
AuC
Immob
ilizatio
nGlucose
oxidation
Alcoh
oloxidation
[64]
2005
Goldim
mob
ilizedmesop
orou
ssilica
Immob
ilizatio
nCy
clohexane
oxidation
[121]
2005
Nitrou
soxide
over
MFI
zeolites
Hydrothermal
Benzeneo
xidatio
n[122]
2005
CoA
PO-5
molecular
sieves
Hydrothermal
Cyclo
hexane
oxidation
[123]
2004
Carbon
-sup
ported
gold
Goldsol
Glucose
oxidation
[124]
2004
Mn-containing
MCM
-41
Impregnatio
nEthylbenzene
oxidation
[72]
2003
CoO119909C
eO2
Cop
recipitaion
Carbon
mon
oxideo
xidatio
n[125]
2002
Goldcatalysts
Immob
ilizatio
nGlucose
oxidation
[126]
2002
Mn(Salen)MCM
-41
mdashOlefin
sepo
xidatio
n[127]
2002
NanostructuredCu
O119909C
eO2
Gas-con
densation
Carbon
mon
oxideo
xidatio
n[128]
2002
Nano-Au
Catalysts
mdashCa
rbon
mon
oxideo
xidatio
n[55]
2001
AuTiO
2Au
TiO
2SiO
2Deposition
-precipitatio
nProp
enee
poxidatio
n[129]
2000
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
yleneo
xidatio
n[130]
1999
Golddispersedon
TS1and
other
titanium-con
tainingsupp
orts
Disp
ersio
nProp
enee
poxidatio
n[131]
1998
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
ylenee
poxidatio
n[61]
1996
Heterop
olycatalysts
containing
Ru(III)
andRh
(III)p
articles
mdashAlkaneo
xidatio
n[132]
1996
Goldsupp
ortedon
ZnOandTiO
2Cop
recipitatio
namp
Deposition
-precipitatio
nCa
rbon
mon
oxideo
xidatio
n[133]
1996
Au-TiO
2Incipientw
etness
impregnatio
nCa
rbon
mon
oxideo
xidatio
n[134]
1995
Bism
uthprom
oted
palladium
catalysts
Ionexchange
Glucose
oxidation
[42]
Journal of Nanomaterials 7
HO HO
OOH
OHOH
OH OH
OHOH
OH
OH O
Glucose Gluconic acid
Catalysts
Figure 2 Conversion of glucose to gluconic acid
Si
ClCl Cl
H
trimethyl(phenyl)silane Tetramethylsilane Trichlorosilane
Si CH3
CH3
CH3
Si CH3
CH3
CH3
H3C
Scheme 1
H OH
Dimethylphenylsilane Dimethylphenylsilane
THF RTSi Si
CH3
CH3 CH3
CH3
+ H2O + H2
AuSiO2
Scheme 2
without any supporting materials [42] On the other handbismuth on palladium or PtPd on carbon supports demon-strated high selectivity and stability and excellent conversionrate overcoming the limitations of the heavy metal supportsSome features such as catalyst type and the role of bismuthsupport are still a disputed issue [42]
Prati and Rossi (1997) [43] studied the oxidation of12-diols and found excellent selectivity with gold catalystover platinum and palladium catalysts The gold catalystshowed unusual selectivity in the oxidation of alcohol to itscorresponding carboxylates whereas Pd or Pt showed lowerselectivity to oxidize ethane-12-diol From this observationthey also concluded that Au is less sensitive to overoxidationandor self-poisoning than Pd or Pt Gold clusters andnanoparticles (NPs) deposited on the metal oxide surfacesuch as Al
2O3and ZrO
2demonstrated unexpected catalytic
activity in the oxidation of glucose with better turnover fre-quency (TOF reaction rate per Au atom surface) In additionto carbon andmetal oxide supports some inorganic polymerssuch as silica could be used as catalytic supports for smallAu nanoparticles (gt10 nm in diameter) [43] The catalyticeffect of Au nanoparticles (25 nm) held by polymer gelwas demonstrated by Ishida et al [44] Polymer supportedAuNPs exhibited higher catalytic performance than AuC inthe oxidation of primary alcohols such as benzyl alcohol tobenzaldehyde in absence of base [45] The catalytic activityof various catalysts for glucose oxidation is summarized inTable 3
32 Selective Oxidation of Silanes to Silanols Silane is aninorganic compound having the silicon atom with chemical
formula SiH4 It is a colorless flammable gas with a sharp
and repulsive smell somewhat similar to that of acetic acidSilane has interest as a precursor of silicon metal Silanemay also be referred to many compounds containing sili-con such as trichlorosilane (SiHCl
3) trimethyl(phenyl)silane
(PhSi(CH3)3) and tetramethylsilane (Si(CH
3)4) (Scheme 1)
The oxidation of silane to corresponding silanols (asfor example dimethylphenylsilane to dimethylphenylsilanolScheme 2) is a key reaction to manufacture building blocksfor the synthesis of silica based polymers [46] and nucle-ophilic couplers in organic synthesis In the past silanolssynthesis was often carried out by stoichiometric oxidationof organosilanes hydrolysis of halosilanes or alkali treat-ment of siloxanes which incurred environmental hazards Incontrast the catalytic oxidation of silanes with water is anecofriendly process since it produces silanols with high selec-tivity producing only hydrogen as a by-product Supportedgold nanoparticles have shown higher catalytic activity andselectivity on silane oxidation over other transition metalcatalysts [47] Mitsudome et al [48] oxidized aliphatic silanesto silanols using hydroxyapatite supported AuNPs in waterat 80∘C Nanoporous gold also showed high reactivity andselectivity towards silanes in acetone at room temperature[49]
Recently John et al [50] have synthesized carbon nano-tube-supported gold nanoparticles which showed turnoverfrequency (TOF) of 18000 hminus1 for silane oxidation in tetrahy-drofuran (THF) at room temperature However the prepa-ration of Au CNT (carbon nanotube) hybrids involved amultistep layer-by-layer assembly which needed expensivereagents which have limited its practicability Li et al [47]
8 Journal of Nanomaterials
Table3Oxidatio
nof
glucoseb
yvario
uscatalysts
Nam
eofcatalysts
Preparationmetho
dRe
actio
ncond
ition
Mainprod
uct
Selectivity
()Re
ferences
SubstrateOxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)
pHSolvent
Goldnano
particleso
ncellu
lose
Deposition
-redu
ction
O2
mdash60
95Water
Gluconica
cid
mdash[41]
AuA
l 2O3
Deposition
-precipitatio
nO
27
6090
Water
Gluconica
cid
97[79]
AuC
Catio
nica
dsorption
O2
760
90Water
Gluconica
cid
97[79]
Au-PdC
Impregnatio
nO
220
5092
5mdash
Gluconica
cid
mdash[103]
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
H2O
240
90mdash
Sodium
D-gluconate
99[102]
AuC
Goldsol
mdash30
5095
mdashGluconica
cid
45[124]
Nanosized
AuSiO
2Stob
erH
2O2
2430
92Water
Gluconica
cid
80[95]
Pb-TeSiO
2Re
peated
impregnatio
nO
215
6090
mdashGluconica
cid
884
[104]
AuPtb
imetallic
nano
particle
Vacuum
drying
O2
260
95mdash
Gluconica
cid
mdash[80]
Journal of Nanomaterials 9
Table 4 Comparison of supported gold catalysts for the oxidation of triethylsilane [47]
Catalysts Reaction condition Conversion rate () Yield ()Substrate Solvent Reaction temperature Time (min) Ausubstrate (mol)
AuSiO2
Triethylsilane
Water 25∘C 3 04 99 99AuTiO2 Water 25∘C 3 04 81 81AuFe2O3 Water 25∘C 3 04 36 36AuZnO Water 25∘C 3 04 89 89AuCeO2 Water 25∘C 3 04 98 98
Catalyst
Decomposition
H2 + O2 H2O2
2H2O2
H2O + 12O2
Hydrogenation H2
Scheme 3 Hydrogen peroxide formation hydrogenation and decomposition
prepared silica supported gold catalysts for the selectiveoxidation of silanes However they observed that silicasupported gold catalysts aremore active than reducible oxides(TiO2 Fe2O3 CeO
2 etc) supported AuNPs Highly dis-
persed silica supported gold catalysts override the reducibleoxides supported AuNPs due to superior adsorption of silanesubstrate on silica support Surprisingly for the oxidationof dimethylphenylsilane in THF at room temperature theAuSiO
2catalyst afforded a TOF of 59400 hminus1 which is the
highest TOF reported to dateThe other oxide supported gold catalysts such as
AuTiO2 AuZnO and AuFe
2O3
were less active thanAuSiO
2 and they afforded a maximum conversion of 90
However the activity of AuCeO2catalyst was very similar to
the AuSiO2catalyst (Table 4)
33 Oxidation of Hydrogen to Hydrogen Peroxide (H2O2)
H2O2is an essential chemical which has long been used
mainly as strong oxidant in various oxidative reactions andbleaching agent as well as a disinfectant It is a green oxidantsince its sole by-product is water In the current decades alot of attention has been paid to the green catalysts and greenchemicals to ensure safety issues in health and environmentIndustries have been using supported Pd catalysts for morethan 90 years for the direct synthesis of H
2O2from H
2and
O2 However the synthesized H
2O2is unstable and under-
goes low-temperature decomposition or hydrogenation towater (Scheme 3) [51] Recently Edwards et al [52] usedAu-catalysts synthesized via coprecipitation or deposition-precipitation method and found very low H
2O2conversion
rateThey also observed that the addition of Au to Pd catalystsby impregnation enhances H
2O2formation They compared
five different catalyst supports namely Al2O3 Fe2O3 TiO2
SiO2
and carbon and found the high conversion withcarbon-supported Au-Pd (Au-PdC)
In 2010 Song et al [53] observed that KMnO4treated
activated carbon in an acidic solution enhances H2O2pro-
duction (78) from hydroxylamine due to the creation ofsurface active quinoid species during oxidation Structure
and surface analyses revealed that KMnO4treatment pro-
duced more phenolic but less carboxylic groups on theactivated carbon under acidic condition confirming thecrucial role of the quinoid groups It was also proposed thatthe quinoid groups served as electron acceptors and redoxmediators in the formation of H
2O2[53]
34 Carbon Monoxide (CO) Oxidation In the last decadeCOoxidation has become an important research area becauseof its involvement in a number of processes such asmethanolsynthesis water gas shift reaction carbon dioxide lasersand automotive exhaust controls [54] Carbon monoxide isa lethal gas for animal life and toxic to the environment[55] The oxidation of CO is a difficult process and hencea highly active oxidation catalyst is required for its efficientremoval from the environment [55] In the past the gold wasconsidered to be inert for CO oxidation [56]
However Haruta et al [57] demonstrated that highlydispersed gold prepared on various metal oxide supportsby coprecipitation and deposition-precipitation methods ishighly active in CO oxidation even below 0∘C temperatureThey found that catalytic performance significantly dependson the catalysts preparation methods and the highest activitywas demonstrated by TiO
2supported gold or platinum
catalysts prepared by deposition-precipitation (DP)The goldcatalysts prepared by photodeposition (PD) and impregna-tion (IMP) methods were less active than those preparedby deposition-precipitation This is because the catalystsprepared by DP method contain higher loading of Au(gt2wt) on smaller particles and are with better dispersionCollectively these features enable the catalyst to show higheractivity oxidizingsim100ofCOat temperatures belowminus20∘CIn 1997 Yuan et al [58] synthesized highly active goldcatalysts for CO oxidation simply by grafting Au-phosphinecomplexes (AuL
3NO3or Au
9L8(NO3)3 L = PPh
3) onto
precipitated Ti(OH)4surfaces This Au-phosphine-Ti(OH)
4
complex was active even below the 0∘C Apart from this Na+ions positively andClminus ions negatively affect the Au-catalyzed
10 Journal of Nanomaterials
C O
OH
C
O
O
O
H
O2
Mx+Mx+
AuIIIAuIIIAu0
O2minus
Figure 3 Plausible mechanism for CO oxidation on oxide supported gold catalyst On the left a CO molecule is chemisorbed onto a lowcoordination number gold atom (yellow sphere) and a hydroxyl ion is moved from the oxide support (pink sphere) to an Au (III) ioncreating an anion vacancy On the right they have reacted to form a carboxylate group and an oxygen molecule occupies the anion vacancyas O2minus (white sphere) This then oxidizes the carboxylate group by abstracting a hydrogen atom forming carbon dioxide and the resultinghydroperoxide ionHO
2
minus then further oxidizes carboxylate species to form another carbon dioxide restoring two hydroxyl ions to the supportsurface completing the catalytic cycle (Adapted with permission from Springer) [145]
O
Catalysts
Propene epoxide
Polyether polyols (66) Propene glycols (30) Propene glycols ether (4)
Polyurethanes or foam Polyesters Solvents
CH3CH=CH2 + O2 + H2CH3CH2ndashCH2 + H2O
Scheme 4 Synthetic products from propene epoxidation reaction
CO oxidation Figure 3 represents the initial stages of COoxidation at the edge of an active gold particle
35 Epoxidation of Propene The oxidation of propene toepoxide is an important reaction for the synthesis of variousindustrial chemicals such as polyether polyols (precursorof polyurethane or foams) propene glycol and propeneglycol ethers (Scheme 4) [59] In the past chlorohydrin andhydroperoxide mediated processes were used for the syn-thesis of propene epoxide Chlorohydrin process producesenvironmentally hazardous chlorinated by-products and thehydroperoxide process is much expensive and producesstyrene and tert-butyl alcohol as by-products Silver catalystswere used in this reaction but poor selectivity and turnoverwere observed [60] However titania supported gold effi-ciently catalyzed the epoxidation reaction at 30ndash120∘C withmore than 90 selectivity in the presence of hydrogen [61]
36 Oxidation of Alcohol The oxidation of alcohols to itscorresponding aldehydes or ketones is a crucial reaction inorganic synthesis Ketones specially acetone are widely usedin the production of various organic as well as fine chemicals[62] Traditional chemical routes use stoichiometric chem-icals such as chromium (VI) reagents dimethyl sulfoxidepermanganates periodates or N-chlorosuccinimide whichare expensive and hazardous Several homogeneous catalystssuch as Pd Cu and Ru are found to selectively catalyzealcohol oxidation However homogeneous catalysis requireshigh pressure oxygen andor organic solvent incurring costand environmental burdens [63] The present ecologicaldeterioration has forced researchers to look for novel andenvironmentally friendly catalytic schemes for the oxidationof alcohol Prati and Porta [64] demonstrated that AuCcatalyst shows higher selectivity toward aldehyde in the oxi-dation of primary alcohols Subsequently Endud and Wong[65] synthesized porous SiSn bimetallic catalyst through
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
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CeramicsJournal of
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CompositesJournal of
NanoparticlesJournal of
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
NanoscienceJournal of
TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Journal of Nanomaterials 3
Disadvantages
Advantages
Major features
Homogeneous
Major features
Catalysts
Heterogeneous
Advantages
Disadvantages
(1) Difficult separation
(3) Huge waste materials (4) Product
(2) Reactor corrosion
(1) Dissolves in reaction medium hence all catalytic sites are available for reaction
(5) Complicated handling
(1) Nonselective to chiral catalysis
(3) Use as fixed beds
(1) Same phase (catalysts reactants and products)
(2) Co dissolved
(3) High selectivity
(4) Easy separation
(2) Reusable (1) Stable
(2) Difficult to study and hence reactionmechanisms are often unknown
(1) Different phases (catalysts reactants and products)
(2) Poor selectivity
(3) No solvent required
Figure 1 Special features advantages and disadvantages of homo- and heterogeneous catalysts
catalyst separation at the end of the reaction Heterogeneouscatalysts are also easier to prepare and handleThese catalystsconsist of fine nanosized powders supported on technicallyinert oxide substrates exhibiting all possible crystallographicfaces The catalyst is often a metal to which chemical andstructural promoters or poisons are added to enhance theefficiency andor the selectivity Currently heterogeneouscatalysis is dominating in industries for chemical trans-formation and energy generation Approximately 90 ofall industrial practices indulge in heterogeneous catalysisThe most recent applications of heterogeneous catalysts aresummarized in Table 2
3 Heterogeneous Metal Catalystsin Oxidation Reactions
Over the last few decades scientists have paid tremen-dous attention to heterogeneous catalysts to overcome the
limitations of their homogeneous counterparts to increaseproducts yields and minimize side reactions Herein wereported a summary of selected oxidation reactions catalyzedby supported metal catalysts
31 Conversion of Glucose to Gluconic Acid Recently theaerobic oxidation of glucose to gluconic acid (Figure 2)has gained much consideration because of its water-solublecleansing properties and application in food additives andbeverage bottle detergents [41] In the past the oxidation ofglucose was carried out via biochemical pathways which arecumbersome multistep process not recyclable and expen-sive [42] The development of catalytic route is probably analternative pathway for the large scale production of gluconicacid from glucose In 1970s researchers used to dope Ptor Pd onto some heavy metals such as bismuth Howeverseveral limitations such as instability poor selectivity andlow conversion rate were encountered with this procedure
4 Journal of Nanomaterials
Table2Re
cent
scenario
inheterogeneou
scatalysis
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2013
Fenano
catalyst
Immob
ilizatio
nEthylbenzenecyclohexeneand
benzylalcoho
loxidation
[18]
2013
AuA
l 2O3Au
CDeposition
-precipitatio
ncatio
nica
dsorption
Glucose
oxidation
[79]
2013
AuPtb
imetallic
nano
particles
mdashGlucose
oxidation
[80]
2013
Goldnano
particles
supp
ortedon
Mg(OH) 2nano
sheets
Colloidaldepo
sition
COoxidation
[81]
2013
AuTiO
2supp
ortedon
ferritics
tainles
sste
elmon
olith
sDire
ctanionice
xchange
COoxidation
[82]
2013
Nanop
orou
sgold
Electro
lytic
dissolution
COoxidation
[83]
2013
P123-stabilized
Au-Agalloy
Coredu
ction
Benzylalcoho
loxidatio
n[84]
2013
Alumina-supp
ortedgold-ruthenium
bimetallic
catalysts
Incipientw
etnessIm
pregnatio
nDeposition
Precipitatio
nCO
oxidation
[54]
2013
AuCuO
catalysts
Cop
recipitatio
nAlcoh
oloxidation
[85]
2013
Cerium
mod
ified
silver
Impregnatio
nAlkylarom
aticcompo
unds
[86]
2013
Pd-Aucatalyst
Deallo
ying
Methano
lelectrooxidation
[87]
2013
AuZnO
andAu
TiO
2catalysts
Colloidaldepo
sition
Methano
loxidatio
n[88]
2013
Microstructured
AuN
i-fiberc
atalyst
Incipientimpregnatin
gAlcoh
oloxidation
[89]
2013
Nanocrystallin
eAgandAu
-Agalloys
supp
ortedon
titania
Deposition
Precipitatio
nCO
oxidation
[90]
2013
Nanosized
Ausupp
ortedon
3-Dordered
mesop
orou
sMnO
2
Deposition
Precipitatio
nOxidatio
nof
carbon
mon
oxidebenzeneandtoluene
[91]
2013
AuFeO119909
Cop
recipitatio
nCO
oxidation
[92]
2013
Nanosized
ruthenium
particlesd
ecorated
carbon
nano
fibers
Solgel
p-Cy
meneo
xidatio
n[93]
2012
AuC
Incipientw
etness
impregnatio
nGlucose
oxidation
[94]
2012
CeA
lPO-5
molecular
sieves
mdashDiphenylm
ethane
oxidation
[10]
2012
Nanosized
gold
onSiO
2Stob
erCy
clohexene
andD-glucose
oxidation
[95]
2012
AuSiO
2Disp
ersio
nSilaneso
xidatio
n[47]
2012
Nanogold-m
esop
orou
ssilica
mdashCO
oxidation
benzylalcoho
loxidatio
n[96]
2012
Nanosized
gold
Disp
ersio
nAlkylbenzeneo
xidatio
n[40]
2012
AgSB
A-15
Impregnatio
nAlkylsubstituted
arom
atics
[35]
2012
Bimetallic
Au-PdMgO
Sol-immob
ilizatio
n(SI)and
adsorptio
n-redu
ction(A
R)Be
nzylalcoho
loxidatio
n[97]
Journal of Nanomaterials 5
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2012
InverseF
e 2O
3Au
(111)m
odelcatalysts
mdashCO
oxidation
[98]
2012
Silica-supp
ortedAu
-Cualloy
mdashAlcoh
oloxidation
[99]
2012
Goldnano
particlessup
ported
onMgO
Deposition
-precipitatio
nAlcoh
oloxidation
[100]
2012
Silica-supp
ortedAu
-CuO119909
Oxidativ
edeallo
ying
Ethano
loxidatio
n[101]
2011
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
oxidation
[102]
2011
Au-PdC
Impregnatio
nGlyoxalandglucoseo
xidatio
n[103]
2011
Pd-Tes
uppo
rted
catalysts
Repeated
impregnatio
nGlucose
oxidation
[104]
2011
Goldnano
particlessup
ported
onfunctio
nalized
mesop
orou
ssilica
One-pot
Synthesis
Cyclo
hexane
oxidation
[105]
2011
Silicas
uppo
rted
cobalt(II)salencomplex
Immob
ilizatio
nAlkylbenzeneo
xidatio
n[70]
2011
Goldnano
wire
smdash
Oxidatio
nof
benzyliccompo
unds
[106]
2011
Cu32[PM
o 12O
40]SiO
2Incipientw
etness
impregnatio
nBe
nzylicalcoho
l[107]
2010
Goldnano
particlesd
epositedon
cellu
lose
Deposition
-reductio
ngrinding
metho
dGlucose
oxidation
[41]
2010
Metallopo
rphyrin
boun
dto
silica
Immob
ilizatio
nEthylbenzene
oxidation
[68]
2010
Hydroph
obized
palladium
Vapo
rdeposition
Glucose
oxidation
[108]
2010
Supp
ortedgold
catalysts
Colloidalgold
depo
sition
COoxidation
[109]
2010
AuH
MScatalysts
Impregnatio
nanddirect
synthesis
Benzylalcoho
loxidatio
n[63]
2010
Mob
ilizedgold
nano
particles
Goldsol
Second
aryalcoho
lsoxidation
[67]
2010
Mesop
orou
sCo 3O
4andAu
Co 3O
4catalysts
Nanocastin
gEthylene
oxidation
[110]
2010
Metal-organicfram
eworksupp
ortedgold
nano
particles
Colloidaldepo
sition
Alcoh
oloxidation
[111]
2010
PtA
l 2O3
Impregnatio
nHeavy
hydrocarbo
nsoxidation
[112]
2009
AuTiO
2Deposition
-precipitatio
nAlcoh
oloxidation
[113]
2009
Co(Ac
O) 2M
n(Ac
O) 2
Dire
ctcond
ensatio
np-xylene
oxidation
[114]
6 Journal of Nanomaterials
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2009
Nickelsub
stitutedcopp
erchromite
spinels
Cop
recipitatio
nAlkylsubstituted
benzeneo
xidatio
n[9]
2007
Goldcatalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[115]
2007
MCM
-48molecular
sieve
mod
ified
with
SnCl
2Po
st-synthesis
mod
ificatio
nAlcoh
oloxidation
[65]
2007
CuO-im
pregnatedmesop
orou
ssilica
Impregnatio
nBe
nzeneo
xidatio
n[116]
2006
Supp
ortedgold
catalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[117]
2006
Au-C
uOA
l 2O3PtA
l 2O3catalysts
Deposition
-precipitatio
nim
pregnatio
nProp
enea
ndprop
aneo
xidatio
n[118]
2006
Manganese
containing
mesop
orou
sMCM
-41and
Al-M
CM-41
molecular
sieves
Impregnatio
np-iso
prop
yltolueneo
xidatio
n[119]
2005
Goldcatalysts
mdashAlcoh
oloxidation
[120]
2005
AuC
Immob
ilizatio
nGlucose
oxidation
Alcoh
oloxidation
[64]
2005
Goldim
mob
ilizedmesop
orou
ssilica
Immob
ilizatio
nCy
clohexane
oxidation
[121]
2005
Nitrou
soxide
over
MFI
zeolites
Hydrothermal
Benzeneo
xidatio
n[122]
2005
CoA
PO-5
molecular
sieves
Hydrothermal
Cyclo
hexane
oxidation
[123]
2004
Carbon
-sup
ported
gold
Goldsol
Glucose
oxidation
[124]
2004
Mn-containing
MCM
-41
Impregnatio
nEthylbenzene
oxidation
[72]
2003
CoO119909C
eO2
Cop
recipitaion
Carbon
mon
oxideo
xidatio
n[125]
2002
Goldcatalysts
Immob
ilizatio
nGlucose
oxidation
[126]
2002
Mn(Salen)MCM
-41
mdashOlefin
sepo
xidatio
n[127]
2002
NanostructuredCu
O119909C
eO2
Gas-con
densation
Carbon
mon
oxideo
xidatio
n[128]
2002
Nano-Au
Catalysts
mdashCa
rbon
mon
oxideo
xidatio
n[55]
2001
AuTiO
2Au
TiO
2SiO
2Deposition
-precipitatio
nProp
enee
poxidatio
n[129]
2000
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
yleneo
xidatio
n[130]
1999
Golddispersedon
TS1and
other
titanium-con
tainingsupp
orts
Disp
ersio
nProp
enee
poxidatio
n[131]
1998
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
ylenee
poxidatio
n[61]
1996
Heterop
olycatalysts
containing
Ru(III)
andRh
(III)p
articles
mdashAlkaneo
xidatio
n[132]
1996
Goldsupp
ortedon
ZnOandTiO
2Cop
recipitatio
namp
Deposition
-precipitatio
nCa
rbon
mon
oxideo
xidatio
n[133]
1996
Au-TiO
2Incipientw
etness
impregnatio
nCa
rbon
mon
oxideo
xidatio
n[134]
1995
Bism
uthprom
oted
palladium
catalysts
Ionexchange
Glucose
oxidation
[42]
Journal of Nanomaterials 7
HO HO
OOH
OHOH
OH OH
OHOH
OH
OH O
Glucose Gluconic acid
Catalysts
Figure 2 Conversion of glucose to gluconic acid
Si
ClCl Cl
H
trimethyl(phenyl)silane Tetramethylsilane Trichlorosilane
Si CH3
CH3
CH3
Si CH3
CH3
CH3
H3C
Scheme 1
H OH
Dimethylphenylsilane Dimethylphenylsilane
THF RTSi Si
CH3
CH3 CH3
CH3
+ H2O + H2
AuSiO2
Scheme 2
without any supporting materials [42] On the other handbismuth on palladium or PtPd on carbon supports demon-strated high selectivity and stability and excellent conversionrate overcoming the limitations of the heavy metal supportsSome features such as catalyst type and the role of bismuthsupport are still a disputed issue [42]
Prati and Rossi (1997) [43] studied the oxidation of12-diols and found excellent selectivity with gold catalystover platinum and palladium catalysts The gold catalystshowed unusual selectivity in the oxidation of alcohol to itscorresponding carboxylates whereas Pd or Pt showed lowerselectivity to oxidize ethane-12-diol From this observationthey also concluded that Au is less sensitive to overoxidationandor self-poisoning than Pd or Pt Gold clusters andnanoparticles (NPs) deposited on the metal oxide surfacesuch as Al
2O3and ZrO
2demonstrated unexpected catalytic
activity in the oxidation of glucose with better turnover fre-quency (TOF reaction rate per Au atom surface) In additionto carbon andmetal oxide supports some inorganic polymerssuch as silica could be used as catalytic supports for smallAu nanoparticles (gt10 nm in diameter) [43] The catalyticeffect of Au nanoparticles (25 nm) held by polymer gelwas demonstrated by Ishida et al [44] Polymer supportedAuNPs exhibited higher catalytic performance than AuC inthe oxidation of primary alcohols such as benzyl alcohol tobenzaldehyde in absence of base [45] The catalytic activityof various catalysts for glucose oxidation is summarized inTable 3
32 Selective Oxidation of Silanes to Silanols Silane is aninorganic compound having the silicon atom with chemical
formula SiH4 It is a colorless flammable gas with a sharp
and repulsive smell somewhat similar to that of acetic acidSilane has interest as a precursor of silicon metal Silanemay also be referred to many compounds containing sili-con such as trichlorosilane (SiHCl
3) trimethyl(phenyl)silane
(PhSi(CH3)3) and tetramethylsilane (Si(CH
3)4) (Scheme 1)
The oxidation of silane to corresponding silanols (asfor example dimethylphenylsilane to dimethylphenylsilanolScheme 2) is a key reaction to manufacture building blocksfor the synthesis of silica based polymers [46] and nucle-ophilic couplers in organic synthesis In the past silanolssynthesis was often carried out by stoichiometric oxidationof organosilanes hydrolysis of halosilanes or alkali treat-ment of siloxanes which incurred environmental hazards Incontrast the catalytic oxidation of silanes with water is anecofriendly process since it produces silanols with high selec-tivity producing only hydrogen as a by-product Supportedgold nanoparticles have shown higher catalytic activity andselectivity on silane oxidation over other transition metalcatalysts [47] Mitsudome et al [48] oxidized aliphatic silanesto silanols using hydroxyapatite supported AuNPs in waterat 80∘C Nanoporous gold also showed high reactivity andselectivity towards silanes in acetone at room temperature[49]
Recently John et al [50] have synthesized carbon nano-tube-supported gold nanoparticles which showed turnoverfrequency (TOF) of 18000 hminus1 for silane oxidation in tetrahy-drofuran (THF) at room temperature However the prepa-ration of Au CNT (carbon nanotube) hybrids involved amultistep layer-by-layer assembly which needed expensivereagents which have limited its practicability Li et al [47]
8 Journal of Nanomaterials
Table3Oxidatio
nof
glucoseb
yvario
uscatalysts
Nam
eofcatalysts
Preparationmetho
dRe
actio
ncond
ition
Mainprod
uct
Selectivity
()Re
ferences
SubstrateOxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)
pHSolvent
Goldnano
particleso
ncellu
lose
Deposition
-redu
ction
O2
mdash60
95Water
Gluconica
cid
mdash[41]
AuA
l 2O3
Deposition
-precipitatio
nO
27
6090
Water
Gluconica
cid
97[79]
AuC
Catio
nica
dsorption
O2
760
90Water
Gluconica
cid
97[79]
Au-PdC
Impregnatio
nO
220
5092
5mdash
Gluconica
cid
mdash[103]
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
H2O
240
90mdash
Sodium
D-gluconate
99[102]
AuC
Goldsol
mdash30
5095
mdashGluconica
cid
45[124]
Nanosized
AuSiO
2Stob
erH
2O2
2430
92Water
Gluconica
cid
80[95]
Pb-TeSiO
2Re
peated
impregnatio
nO
215
6090
mdashGluconica
cid
884
[104]
AuPtb
imetallic
nano
particle
Vacuum
drying
O2
260
95mdash
Gluconica
cid
mdash[80]
Journal of Nanomaterials 9
Table 4 Comparison of supported gold catalysts for the oxidation of triethylsilane [47]
Catalysts Reaction condition Conversion rate () Yield ()Substrate Solvent Reaction temperature Time (min) Ausubstrate (mol)
AuSiO2
Triethylsilane
Water 25∘C 3 04 99 99AuTiO2 Water 25∘C 3 04 81 81AuFe2O3 Water 25∘C 3 04 36 36AuZnO Water 25∘C 3 04 89 89AuCeO2 Water 25∘C 3 04 98 98
Catalyst
Decomposition
H2 + O2 H2O2
2H2O2
H2O + 12O2
Hydrogenation H2
Scheme 3 Hydrogen peroxide formation hydrogenation and decomposition
prepared silica supported gold catalysts for the selectiveoxidation of silanes However they observed that silicasupported gold catalysts aremore active than reducible oxides(TiO2 Fe2O3 CeO
2 etc) supported AuNPs Highly dis-
persed silica supported gold catalysts override the reducibleoxides supported AuNPs due to superior adsorption of silanesubstrate on silica support Surprisingly for the oxidationof dimethylphenylsilane in THF at room temperature theAuSiO
2catalyst afforded a TOF of 59400 hminus1 which is the
highest TOF reported to dateThe other oxide supported gold catalysts such as
AuTiO2 AuZnO and AuFe
2O3
were less active thanAuSiO
2 and they afforded a maximum conversion of 90
However the activity of AuCeO2catalyst was very similar to
the AuSiO2catalyst (Table 4)
33 Oxidation of Hydrogen to Hydrogen Peroxide (H2O2)
H2O2is an essential chemical which has long been used
mainly as strong oxidant in various oxidative reactions andbleaching agent as well as a disinfectant It is a green oxidantsince its sole by-product is water In the current decades alot of attention has been paid to the green catalysts and greenchemicals to ensure safety issues in health and environmentIndustries have been using supported Pd catalysts for morethan 90 years for the direct synthesis of H
2O2from H
2and
O2 However the synthesized H
2O2is unstable and under-
goes low-temperature decomposition or hydrogenation towater (Scheme 3) [51] Recently Edwards et al [52] usedAu-catalysts synthesized via coprecipitation or deposition-precipitation method and found very low H
2O2conversion
rateThey also observed that the addition of Au to Pd catalystsby impregnation enhances H
2O2formation They compared
five different catalyst supports namely Al2O3 Fe2O3 TiO2
SiO2
and carbon and found the high conversion withcarbon-supported Au-Pd (Au-PdC)
In 2010 Song et al [53] observed that KMnO4treated
activated carbon in an acidic solution enhances H2O2pro-
duction (78) from hydroxylamine due to the creation ofsurface active quinoid species during oxidation Structure
and surface analyses revealed that KMnO4treatment pro-
duced more phenolic but less carboxylic groups on theactivated carbon under acidic condition confirming thecrucial role of the quinoid groups It was also proposed thatthe quinoid groups served as electron acceptors and redoxmediators in the formation of H
2O2[53]
34 Carbon Monoxide (CO) Oxidation In the last decadeCOoxidation has become an important research area becauseof its involvement in a number of processes such asmethanolsynthesis water gas shift reaction carbon dioxide lasersand automotive exhaust controls [54] Carbon monoxide isa lethal gas for animal life and toxic to the environment[55] The oxidation of CO is a difficult process and hencea highly active oxidation catalyst is required for its efficientremoval from the environment [55] In the past the gold wasconsidered to be inert for CO oxidation [56]
However Haruta et al [57] demonstrated that highlydispersed gold prepared on various metal oxide supportsby coprecipitation and deposition-precipitation methods ishighly active in CO oxidation even below 0∘C temperatureThey found that catalytic performance significantly dependson the catalysts preparation methods and the highest activitywas demonstrated by TiO
2supported gold or platinum
catalysts prepared by deposition-precipitation (DP)The goldcatalysts prepared by photodeposition (PD) and impregna-tion (IMP) methods were less active than those preparedby deposition-precipitation This is because the catalystsprepared by DP method contain higher loading of Au(gt2wt) on smaller particles and are with better dispersionCollectively these features enable the catalyst to show higheractivity oxidizingsim100ofCOat temperatures belowminus20∘CIn 1997 Yuan et al [58] synthesized highly active goldcatalysts for CO oxidation simply by grafting Au-phosphinecomplexes (AuL
3NO3or Au
9L8(NO3)3 L = PPh
3) onto
precipitated Ti(OH)4surfaces This Au-phosphine-Ti(OH)
4
complex was active even below the 0∘C Apart from this Na+ions positively andClminus ions negatively affect the Au-catalyzed
10 Journal of Nanomaterials
C O
OH
C
O
O
O
H
O2
Mx+Mx+
AuIIIAuIIIAu0
O2minus
Figure 3 Plausible mechanism for CO oxidation on oxide supported gold catalyst On the left a CO molecule is chemisorbed onto a lowcoordination number gold atom (yellow sphere) and a hydroxyl ion is moved from the oxide support (pink sphere) to an Au (III) ioncreating an anion vacancy On the right they have reacted to form a carboxylate group and an oxygen molecule occupies the anion vacancyas O2minus (white sphere) This then oxidizes the carboxylate group by abstracting a hydrogen atom forming carbon dioxide and the resultinghydroperoxide ionHO
2
minus then further oxidizes carboxylate species to form another carbon dioxide restoring two hydroxyl ions to the supportsurface completing the catalytic cycle (Adapted with permission from Springer) [145]
O
Catalysts
Propene epoxide
Polyether polyols (66) Propene glycols (30) Propene glycols ether (4)
Polyurethanes or foam Polyesters Solvents
CH3CH=CH2 + O2 + H2CH3CH2ndashCH2 + H2O
Scheme 4 Synthetic products from propene epoxidation reaction
CO oxidation Figure 3 represents the initial stages of COoxidation at the edge of an active gold particle
35 Epoxidation of Propene The oxidation of propene toepoxide is an important reaction for the synthesis of variousindustrial chemicals such as polyether polyols (precursorof polyurethane or foams) propene glycol and propeneglycol ethers (Scheme 4) [59] In the past chlorohydrin andhydroperoxide mediated processes were used for the syn-thesis of propene epoxide Chlorohydrin process producesenvironmentally hazardous chlorinated by-products and thehydroperoxide process is much expensive and producesstyrene and tert-butyl alcohol as by-products Silver catalystswere used in this reaction but poor selectivity and turnoverwere observed [60] However titania supported gold effi-ciently catalyzed the epoxidation reaction at 30ndash120∘C withmore than 90 selectivity in the presence of hydrogen [61]
36 Oxidation of Alcohol The oxidation of alcohols to itscorresponding aldehydes or ketones is a crucial reaction inorganic synthesis Ketones specially acetone are widely usedin the production of various organic as well as fine chemicals[62] Traditional chemical routes use stoichiometric chem-icals such as chromium (VI) reagents dimethyl sulfoxidepermanganates periodates or N-chlorosuccinimide whichare expensive and hazardous Several homogeneous catalystssuch as Pd Cu and Ru are found to selectively catalyzealcohol oxidation However homogeneous catalysis requireshigh pressure oxygen andor organic solvent incurring costand environmental burdens [63] The present ecologicaldeterioration has forced researchers to look for novel andenvironmentally friendly catalytic schemes for the oxidationof alcohol Prati and Porta [64] demonstrated that AuCcatalyst shows higher selectivity toward aldehyde in the oxi-dation of primary alcohols Subsequently Endud and Wong[65] synthesized porous SiSn bimetallic catalyst through
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
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[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
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CeramicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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NanoparticlesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
NanoscienceJournal of
TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
4 Journal of Nanomaterials
Table2Re
cent
scenario
inheterogeneou
scatalysis
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2013
Fenano
catalyst
Immob
ilizatio
nEthylbenzenecyclohexeneand
benzylalcoho
loxidation
[18]
2013
AuA
l 2O3Au
CDeposition
-precipitatio
ncatio
nica
dsorption
Glucose
oxidation
[79]
2013
AuPtb
imetallic
nano
particles
mdashGlucose
oxidation
[80]
2013
Goldnano
particles
supp
ortedon
Mg(OH) 2nano
sheets
Colloidaldepo
sition
COoxidation
[81]
2013
AuTiO
2supp
ortedon
ferritics
tainles
sste
elmon
olith
sDire
ctanionice
xchange
COoxidation
[82]
2013
Nanop
orou
sgold
Electro
lytic
dissolution
COoxidation
[83]
2013
P123-stabilized
Au-Agalloy
Coredu
ction
Benzylalcoho
loxidatio
n[84]
2013
Alumina-supp
ortedgold-ruthenium
bimetallic
catalysts
Incipientw
etnessIm
pregnatio
nDeposition
Precipitatio
nCO
oxidation
[54]
2013
AuCuO
catalysts
Cop
recipitatio
nAlcoh
oloxidation
[85]
2013
Cerium
mod
ified
silver
Impregnatio
nAlkylarom
aticcompo
unds
[86]
2013
Pd-Aucatalyst
Deallo
ying
Methano
lelectrooxidation
[87]
2013
AuZnO
andAu
TiO
2catalysts
Colloidaldepo
sition
Methano
loxidatio
n[88]
2013
Microstructured
AuN
i-fiberc
atalyst
Incipientimpregnatin
gAlcoh
oloxidation
[89]
2013
Nanocrystallin
eAgandAu
-Agalloys
supp
ortedon
titania
Deposition
Precipitatio
nCO
oxidation
[90]
2013
Nanosized
Ausupp
ortedon
3-Dordered
mesop
orou
sMnO
2
Deposition
Precipitatio
nOxidatio
nof
carbon
mon
oxidebenzeneandtoluene
[91]
2013
AuFeO119909
Cop
recipitatio
nCO
oxidation
[92]
2013
Nanosized
ruthenium
particlesd
ecorated
carbon
nano
fibers
Solgel
p-Cy
meneo
xidatio
n[93]
2012
AuC
Incipientw
etness
impregnatio
nGlucose
oxidation
[94]
2012
CeA
lPO-5
molecular
sieves
mdashDiphenylm
ethane
oxidation
[10]
2012
Nanosized
gold
onSiO
2Stob
erCy
clohexene
andD-glucose
oxidation
[95]
2012
AuSiO
2Disp
ersio
nSilaneso
xidatio
n[47]
2012
Nanogold-m
esop
orou
ssilica
mdashCO
oxidation
benzylalcoho
loxidatio
n[96]
2012
Nanosized
gold
Disp
ersio
nAlkylbenzeneo
xidatio
n[40]
2012
AgSB
A-15
Impregnatio
nAlkylsubstituted
arom
atics
[35]
2012
Bimetallic
Au-PdMgO
Sol-immob
ilizatio
n(SI)and
adsorptio
n-redu
ction(A
R)Be
nzylalcoho
loxidatio
n[97]
Journal of Nanomaterials 5
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2012
InverseF
e 2O
3Au
(111)m
odelcatalysts
mdashCO
oxidation
[98]
2012
Silica-supp
ortedAu
-Cualloy
mdashAlcoh
oloxidation
[99]
2012
Goldnano
particlessup
ported
onMgO
Deposition
-precipitatio
nAlcoh
oloxidation
[100]
2012
Silica-supp
ortedAu
-CuO119909
Oxidativ
edeallo
ying
Ethano
loxidatio
n[101]
2011
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
oxidation
[102]
2011
Au-PdC
Impregnatio
nGlyoxalandglucoseo
xidatio
n[103]
2011
Pd-Tes
uppo
rted
catalysts
Repeated
impregnatio
nGlucose
oxidation
[104]
2011
Goldnano
particlessup
ported
onfunctio
nalized
mesop
orou
ssilica
One-pot
Synthesis
Cyclo
hexane
oxidation
[105]
2011
Silicas
uppo
rted
cobalt(II)salencomplex
Immob
ilizatio
nAlkylbenzeneo
xidatio
n[70]
2011
Goldnano
wire
smdash
Oxidatio
nof
benzyliccompo
unds
[106]
2011
Cu32[PM
o 12O
40]SiO
2Incipientw
etness
impregnatio
nBe
nzylicalcoho
l[107]
2010
Goldnano
particlesd
epositedon
cellu
lose
Deposition
-reductio
ngrinding
metho
dGlucose
oxidation
[41]
2010
Metallopo
rphyrin
boun
dto
silica
Immob
ilizatio
nEthylbenzene
oxidation
[68]
2010
Hydroph
obized
palladium
Vapo
rdeposition
Glucose
oxidation
[108]
2010
Supp
ortedgold
catalysts
Colloidalgold
depo
sition
COoxidation
[109]
2010
AuH
MScatalysts
Impregnatio
nanddirect
synthesis
Benzylalcoho
loxidatio
n[63]
2010
Mob
ilizedgold
nano
particles
Goldsol
Second
aryalcoho
lsoxidation
[67]
2010
Mesop
orou
sCo 3O
4andAu
Co 3O
4catalysts
Nanocastin
gEthylene
oxidation
[110]
2010
Metal-organicfram
eworksupp
ortedgold
nano
particles
Colloidaldepo
sition
Alcoh
oloxidation
[111]
2010
PtA
l 2O3
Impregnatio
nHeavy
hydrocarbo
nsoxidation
[112]
2009
AuTiO
2Deposition
-precipitatio
nAlcoh
oloxidation
[113]
2009
Co(Ac
O) 2M
n(Ac
O) 2
Dire
ctcond
ensatio
np-xylene
oxidation
[114]
6 Journal of Nanomaterials
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2009
Nickelsub
stitutedcopp
erchromite
spinels
Cop
recipitatio
nAlkylsubstituted
benzeneo
xidatio
n[9]
2007
Goldcatalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[115]
2007
MCM
-48molecular
sieve
mod
ified
with
SnCl
2Po
st-synthesis
mod
ificatio
nAlcoh
oloxidation
[65]
2007
CuO-im
pregnatedmesop
orou
ssilica
Impregnatio
nBe
nzeneo
xidatio
n[116]
2006
Supp
ortedgold
catalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[117]
2006
Au-C
uOA
l 2O3PtA
l 2O3catalysts
Deposition
-precipitatio
nim
pregnatio
nProp
enea
ndprop
aneo
xidatio
n[118]
2006
Manganese
containing
mesop
orou
sMCM
-41and
Al-M
CM-41
molecular
sieves
Impregnatio
np-iso
prop
yltolueneo
xidatio
n[119]
2005
Goldcatalysts
mdashAlcoh
oloxidation
[120]
2005
AuC
Immob
ilizatio
nGlucose
oxidation
Alcoh
oloxidation
[64]
2005
Goldim
mob
ilizedmesop
orou
ssilica
Immob
ilizatio
nCy
clohexane
oxidation
[121]
2005
Nitrou
soxide
over
MFI
zeolites
Hydrothermal
Benzeneo
xidatio
n[122]
2005
CoA
PO-5
molecular
sieves
Hydrothermal
Cyclo
hexane
oxidation
[123]
2004
Carbon
-sup
ported
gold
Goldsol
Glucose
oxidation
[124]
2004
Mn-containing
MCM
-41
Impregnatio
nEthylbenzene
oxidation
[72]
2003
CoO119909C
eO2
Cop
recipitaion
Carbon
mon
oxideo
xidatio
n[125]
2002
Goldcatalysts
Immob
ilizatio
nGlucose
oxidation
[126]
2002
Mn(Salen)MCM
-41
mdashOlefin
sepo
xidatio
n[127]
2002
NanostructuredCu
O119909C
eO2
Gas-con
densation
Carbon
mon
oxideo
xidatio
n[128]
2002
Nano-Au
Catalysts
mdashCa
rbon
mon
oxideo
xidatio
n[55]
2001
AuTiO
2Au
TiO
2SiO
2Deposition
-precipitatio
nProp
enee
poxidatio
n[129]
2000
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
yleneo
xidatio
n[130]
1999
Golddispersedon
TS1and
other
titanium-con
tainingsupp
orts
Disp
ersio
nProp
enee
poxidatio
n[131]
1998
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
ylenee
poxidatio
n[61]
1996
Heterop
olycatalysts
containing
Ru(III)
andRh
(III)p
articles
mdashAlkaneo
xidatio
n[132]
1996
Goldsupp
ortedon
ZnOandTiO
2Cop
recipitatio
namp
Deposition
-precipitatio
nCa
rbon
mon
oxideo
xidatio
n[133]
1996
Au-TiO
2Incipientw
etness
impregnatio
nCa
rbon
mon
oxideo
xidatio
n[134]
1995
Bism
uthprom
oted
palladium
catalysts
Ionexchange
Glucose
oxidation
[42]
Journal of Nanomaterials 7
HO HO
OOH
OHOH
OH OH
OHOH
OH
OH O
Glucose Gluconic acid
Catalysts
Figure 2 Conversion of glucose to gluconic acid
Si
ClCl Cl
H
trimethyl(phenyl)silane Tetramethylsilane Trichlorosilane
Si CH3
CH3
CH3
Si CH3
CH3
CH3
H3C
Scheme 1
H OH
Dimethylphenylsilane Dimethylphenylsilane
THF RTSi Si
CH3
CH3 CH3
CH3
+ H2O + H2
AuSiO2
Scheme 2
without any supporting materials [42] On the other handbismuth on palladium or PtPd on carbon supports demon-strated high selectivity and stability and excellent conversionrate overcoming the limitations of the heavy metal supportsSome features such as catalyst type and the role of bismuthsupport are still a disputed issue [42]
Prati and Rossi (1997) [43] studied the oxidation of12-diols and found excellent selectivity with gold catalystover platinum and palladium catalysts The gold catalystshowed unusual selectivity in the oxidation of alcohol to itscorresponding carboxylates whereas Pd or Pt showed lowerselectivity to oxidize ethane-12-diol From this observationthey also concluded that Au is less sensitive to overoxidationandor self-poisoning than Pd or Pt Gold clusters andnanoparticles (NPs) deposited on the metal oxide surfacesuch as Al
2O3and ZrO
2demonstrated unexpected catalytic
activity in the oxidation of glucose with better turnover fre-quency (TOF reaction rate per Au atom surface) In additionto carbon andmetal oxide supports some inorganic polymerssuch as silica could be used as catalytic supports for smallAu nanoparticles (gt10 nm in diameter) [43] The catalyticeffect of Au nanoparticles (25 nm) held by polymer gelwas demonstrated by Ishida et al [44] Polymer supportedAuNPs exhibited higher catalytic performance than AuC inthe oxidation of primary alcohols such as benzyl alcohol tobenzaldehyde in absence of base [45] The catalytic activityof various catalysts for glucose oxidation is summarized inTable 3
32 Selective Oxidation of Silanes to Silanols Silane is aninorganic compound having the silicon atom with chemical
formula SiH4 It is a colorless flammable gas with a sharp
and repulsive smell somewhat similar to that of acetic acidSilane has interest as a precursor of silicon metal Silanemay also be referred to many compounds containing sili-con such as trichlorosilane (SiHCl
3) trimethyl(phenyl)silane
(PhSi(CH3)3) and tetramethylsilane (Si(CH
3)4) (Scheme 1)
The oxidation of silane to corresponding silanols (asfor example dimethylphenylsilane to dimethylphenylsilanolScheme 2) is a key reaction to manufacture building blocksfor the synthesis of silica based polymers [46] and nucle-ophilic couplers in organic synthesis In the past silanolssynthesis was often carried out by stoichiometric oxidationof organosilanes hydrolysis of halosilanes or alkali treat-ment of siloxanes which incurred environmental hazards Incontrast the catalytic oxidation of silanes with water is anecofriendly process since it produces silanols with high selec-tivity producing only hydrogen as a by-product Supportedgold nanoparticles have shown higher catalytic activity andselectivity on silane oxidation over other transition metalcatalysts [47] Mitsudome et al [48] oxidized aliphatic silanesto silanols using hydroxyapatite supported AuNPs in waterat 80∘C Nanoporous gold also showed high reactivity andselectivity towards silanes in acetone at room temperature[49]
Recently John et al [50] have synthesized carbon nano-tube-supported gold nanoparticles which showed turnoverfrequency (TOF) of 18000 hminus1 for silane oxidation in tetrahy-drofuran (THF) at room temperature However the prepa-ration of Au CNT (carbon nanotube) hybrids involved amultistep layer-by-layer assembly which needed expensivereagents which have limited its practicability Li et al [47]
8 Journal of Nanomaterials
Table3Oxidatio
nof
glucoseb
yvario
uscatalysts
Nam
eofcatalysts
Preparationmetho
dRe
actio
ncond
ition
Mainprod
uct
Selectivity
()Re
ferences
SubstrateOxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)
pHSolvent
Goldnano
particleso
ncellu
lose
Deposition
-redu
ction
O2
mdash60
95Water
Gluconica
cid
mdash[41]
AuA
l 2O3
Deposition
-precipitatio
nO
27
6090
Water
Gluconica
cid
97[79]
AuC
Catio
nica
dsorption
O2
760
90Water
Gluconica
cid
97[79]
Au-PdC
Impregnatio
nO
220
5092
5mdash
Gluconica
cid
mdash[103]
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
H2O
240
90mdash
Sodium
D-gluconate
99[102]
AuC
Goldsol
mdash30
5095
mdashGluconica
cid
45[124]
Nanosized
AuSiO
2Stob
erH
2O2
2430
92Water
Gluconica
cid
80[95]
Pb-TeSiO
2Re
peated
impregnatio
nO
215
6090
mdashGluconica
cid
884
[104]
AuPtb
imetallic
nano
particle
Vacuum
drying
O2
260
95mdash
Gluconica
cid
mdash[80]
Journal of Nanomaterials 9
Table 4 Comparison of supported gold catalysts for the oxidation of triethylsilane [47]
Catalysts Reaction condition Conversion rate () Yield ()Substrate Solvent Reaction temperature Time (min) Ausubstrate (mol)
AuSiO2
Triethylsilane
Water 25∘C 3 04 99 99AuTiO2 Water 25∘C 3 04 81 81AuFe2O3 Water 25∘C 3 04 36 36AuZnO Water 25∘C 3 04 89 89AuCeO2 Water 25∘C 3 04 98 98
Catalyst
Decomposition
H2 + O2 H2O2
2H2O2
H2O + 12O2
Hydrogenation H2
Scheme 3 Hydrogen peroxide formation hydrogenation and decomposition
prepared silica supported gold catalysts for the selectiveoxidation of silanes However they observed that silicasupported gold catalysts aremore active than reducible oxides(TiO2 Fe2O3 CeO
2 etc) supported AuNPs Highly dis-
persed silica supported gold catalysts override the reducibleoxides supported AuNPs due to superior adsorption of silanesubstrate on silica support Surprisingly for the oxidationof dimethylphenylsilane in THF at room temperature theAuSiO
2catalyst afforded a TOF of 59400 hminus1 which is the
highest TOF reported to dateThe other oxide supported gold catalysts such as
AuTiO2 AuZnO and AuFe
2O3
were less active thanAuSiO
2 and they afforded a maximum conversion of 90
However the activity of AuCeO2catalyst was very similar to
the AuSiO2catalyst (Table 4)
33 Oxidation of Hydrogen to Hydrogen Peroxide (H2O2)
H2O2is an essential chemical which has long been used
mainly as strong oxidant in various oxidative reactions andbleaching agent as well as a disinfectant It is a green oxidantsince its sole by-product is water In the current decades alot of attention has been paid to the green catalysts and greenchemicals to ensure safety issues in health and environmentIndustries have been using supported Pd catalysts for morethan 90 years for the direct synthesis of H
2O2from H
2and
O2 However the synthesized H
2O2is unstable and under-
goes low-temperature decomposition or hydrogenation towater (Scheme 3) [51] Recently Edwards et al [52] usedAu-catalysts synthesized via coprecipitation or deposition-precipitation method and found very low H
2O2conversion
rateThey also observed that the addition of Au to Pd catalystsby impregnation enhances H
2O2formation They compared
five different catalyst supports namely Al2O3 Fe2O3 TiO2
SiO2
and carbon and found the high conversion withcarbon-supported Au-Pd (Au-PdC)
In 2010 Song et al [53] observed that KMnO4treated
activated carbon in an acidic solution enhances H2O2pro-
duction (78) from hydroxylamine due to the creation ofsurface active quinoid species during oxidation Structure
and surface analyses revealed that KMnO4treatment pro-
duced more phenolic but less carboxylic groups on theactivated carbon under acidic condition confirming thecrucial role of the quinoid groups It was also proposed thatthe quinoid groups served as electron acceptors and redoxmediators in the formation of H
2O2[53]
34 Carbon Monoxide (CO) Oxidation In the last decadeCOoxidation has become an important research area becauseof its involvement in a number of processes such asmethanolsynthesis water gas shift reaction carbon dioxide lasersand automotive exhaust controls [54] Carbon monoxide isa lethal gas for animal life and toxic to the environment[55] The oxidation of CO is a difficult process and hencea highly active oxidation catalyst is required for its efficientremoval from the environment [55] In the past the gold wasconsidered to be inert for CO oxidation [56]
However Haruta et al [57] demonstrated that highlydispersed gold prepared on various metal oxide supportsby coprecipitation and deposition-precipitation methods ishighly active in CO oxidation even below 0∘C temperatureThey found that catalytic performance significantly dependson the catalysts preparation methods and the highest activitywas demonstrated by TiO
2supported gold or platinum
catalysts prepared by deposition-precipitation (DP)The goldcatalysts prepared by photodeposition (PD) and impregna-tion (IMP) methods were less active than those preparedby deposition-precipitation This is because the catalystsprepared by DP method contain higher loading of Au(gt2wt) on smaller particles and are with better dispersionCollectively these features enable the catalyst to show higheractivity oxidizingsim100ofCOat temperatures belowminus20∘CIn 1997 Yuan et al [58] synthesized highly active goldcatalysts for CO oxidation simply by grafting Au-phosphinecomplexes (AuL
3NO3or Au
9L8(NO3)3 L = PPh
3) onto
precipitated Ti(OH)4surfaces This Au-phosphine-Ti(OH)
4
complex was active even below the 0∘C Apart from this Na+ions positively andClminus ions negatively affect the Au-catalyzed
10 Journal of Nanomaterials
C O
OH
C
O
O
O
H
O2
Mx+Mx+
AuIIIAuIIIAu0
O2minus
Figure 3 Plausible mechanism for CO oxidation on oxide supported gold catalyst On the left a CO molecule is chemisorbed onto a lowcoordination number gold atom (yellow sphere) and a hydroxyl ion is moved from the oxide support (pink sphere) to an Au (III) ioncreating an anion vacancy On the right they have reacted to form a carboxylate group and an oxygen molecule occupies the anion vacancyas O2minus (white sphere) This then oxidizes the carboxylate group by abstracting a hydrogen atom forming carbon dioxide and the resultinghydroperoxide ionHO
2
minus then further oxidizes carboxylate species to form another carbon dioxide restoring two hydroxyl ions to the supportsurface completing the catalytic cycle (Adapted with permission from Springer) [145]
O
Catalysts
Propene epoxide
Polyether polyols (66) Propene glycols (30) Propene glycols ether (4)
Polyurethanes or foam Polyesters Solvents
CH3CH=CH2 + O2 + H2CH3CH2ndashCH2 + H2O
Scheme 4 Synthetic products from propene epoxidation reaction
CO oxidation Figure 3 represents the initial stages of COoxidation at the edge of an active gold particle
35 Epoxidation of Propene The oxidation of propene toepoxide is an important reaction for the synthesis of variousindustrial chemicals such as polyether polyols (precursorof polyurethane or foams) propene glycol and propeneglycol ethers (Scheme 4) [59] In the past chlorohydrin andhydroperoxide mediated processes were used for the syn-thesis of propene epoxide Chlorohydrin process producesenvironmentally hazardous chlorinated by-products and thehydroperoxide process is much expensive and producesstyrene and tert-butyl alcohol as by-products Silver catalystswere used in this reaction but poor selectivity and turnoverwere observed [60] However titania supported gold effi-ciently catalyzed the epoxidation reaction at 30ndash120∘C withmore than 90 selectivity in the presence of hydrogen [61]
36 Oxidation of Alcohol The oxidation of alcohols to itscorresponding aldehydes or ketones is a crucial reaction inorganic synthesis Ketones specially acetone are widely usedin the production of various organic as well as fine chemicals[62] Traditional chemical routes use stoichiometric chem-icals such as chromium (VI) reagents dimethyl sulfoxidepermanganates periodates or N-chlorosuccinimide whichare expensive and hazardous Several homogeneous catalystssuch as Pd Cu and Ru are found to selectively catalyzealcohol oxidation However homogeneous catalysis requireshigh pressure oxygen andor organic solvent incurring costand environmental burdens [63] The present ecologicaldeterioration has forced researchers to look for novel andenvironmentally friendly catalytic schemes for the oxidationof alcohol Prati and Porta [64] demonstrated that AuCcatalyst shows higher selectivity toward aldehyde in the oxi-dation of primary alcohols Subsequently Endud and Wong[65] synthesized porous SiSn bimetallic catalyst through
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Polymer ScienceInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CeramicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CompositesJournal of
NanoparticlesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
NanoscienceJournal of
TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MetallurgyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Journal of Nanomaterials 5
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2012
InverseF
e 2O
3Au
(111)m
odelcatalysts
mdashCO
oxidation
[98]
2012
Silica-supp
ortedAu
-Cualloy
mdashAlcoh
oloxidation
[99]
2012
Goldnano
particlessup
ported
onMgO
Deposition
-precipitatio
nAlcoh
oloxidation
[100]
2012
Silica-supp
ortedAu
-CuO119909
Oxidativ
edeallo
ying
Ethano
loxidatio
n[101]
2011
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
oxidation
[102]
2011
Au-PdC
Impregnatio
nGlyoxalandglucoseo
xidatio
n[103]
2011
Pd-Tes
uppo
rted
catalysts
Repeated
impregnatio
nGlucose
oxidation
[104]
2011
Goldnano
particlessup
ported
onfunctio
nalized
mesop
orou
ssilica
One-pot
Synthesis
Cyclo
hexane
oxidation
[105]
2011
Silicas
uppo
rted
cobalt(II)salencomplex
Immob
ilizatio
nAlkylbenzeneo
xidatio
n[70]
2011
Goldnano
wire
smdash
Oxidatio
nof
benzyliccompo
unds
[106]
2011
Cu32[PM
o 12O
40]SiO
2Incipientw
etness
impregnatio
nBe
nzylicalcoho
l[107]
2010
Goldnano
particlesd
epositedon
cellu
lose
Deposition
-reductio
ngrinding
metho
dGlucose
oxidation
[41]
2010
Metallopo
rphyrin
boun
dto
silica
Immob
ilizatio
nEthylbenzene
oxidation
[68]
2010
Hydroph
obized
palladium
Vapo
rdeposition
Glucose
oxidation
[108]
2010
Supp
ortedgold
catalysts
Colloidalgold
depo
sition
COoxidation
[109]
2010
AuH
MScatalysts
Impregnatio
nanddirect
synthesis
Benzylalcoho
loxidatio
n[63]
2010
Mob
ilizedgold
nano
particles
Goldsol
Second
aryalcoho
lsoxidation
[67]
2010
Mesop
orou
sCo 3O
4andAu
Co 3O
4catalysts
Nanocastin
gEthylene
oxidation
[110]
2010
Metal-organicfram
eworksupp
ortedgold
nano
particles
Colloidaldepo
sition
Alcoh
oloxidation
[111]
2010
PtA
l 2O3
Impregnatio
nHeavy
hydrocarbo
nsoxidation
[112]
2009
AuTiO
2Deposition
-precipitatio
nAlcoh
oloxidation
[113]
2009
Co(Ac
O) 2M
n(Ac
O) 2
Dire
ctcond
ensatio
np-xylene
oxidation
[114]
6 Journal of Nanomaterials
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2009
Nickelsub
stitutedcopp
erchromite
spinels
Cop
recipitatio
nAlkylsubstituted
benzeneo
xidatio
n[9]
2007
Goldcatalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[115]
2007
MCM
-48molecular
sieve
mod
ified
with
SnCl
2Po
st-synthesis
mod
ificatio
nAlcoh
oloxidation
[65]
2007
CuO-im
pregnatedmesop
orou
ssilica
Impregnatio
nBe
nzeneo
xidatio
n[116]
2006
Supp
ortedgold
catalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[117]
2006
Au-C
uOA
l 2O3PtA
l 2O3catalysts
Deposition
-precipitatio
nim
pregnatio
nProp
enea
ndprop
aneo
xidatio
n[118]
2006
Manganese
containing
mesop
orou
sMCM
-41and
Al-M
CM-41
molecular
sieves
Impregnatio
np-iso
prop
yltolueneo
xidatio
n[119]
2005
Goldcatalysts
mdashAlcoh
oloxidation
[120]
2005
AuC
Immob
ilizatio
nGlucose
oxidation
Alcoh
oloxidation
[64]
2005
Goldim
mob
ilizedmesop
orou
ssilica
Immob
ilizatio
nCy
clohexane
oxidation
[121]
2005
Nitrou
soxide
over
MFI
zeolites
Hydrothermal
Benzeneo
xidatio
n[122]
2005
CoA
PO-5
molecular
sieves
Hydrothermal
Cyclo
hexane
oxidation
[123]
2004
Carbon
-sup
ported
gold
Goldsol
Glucose
oxidation
[124]
2004
Mn-containing
MCM
-41
Impregnatio
nEthylbenzene
oxidation
[72]
2003
CoO119909C
eO2
Cop
recipitaion
Carbon
mon
oxideo
xidatio
n[125]
2002
Goldcatalysts
Immob
ilizatio
nGlucose
oxidation
[126]
2002
Mn(Salen)MCM
-41
mdashOlefin
sepo
xidatio
n[127]
2002
NanostructuredCu
O119909C
eO2
Gas-con
densation
Carbon
mon
oxideo
xidatio
n[128]
2002
Nano-Au
Catalysts
mdashCa
rbon
mon
oxideo
xidatio
n[55]
2001
AuTiO
2Au
TiO
2SiO
2Deposition
-precipitatio
nProp
enee
poxidatio
n[129]
2000
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
yleneo
xidatio
n[130]
1999
Golddispersedon
TS1and
other
titanium-con
tainingsupp
orts
Disp
ersio
nProp
enee
poxidatio
n[131]
1998
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
ylenee
poxidatio
n[61]
1996
Heterop
olycatalysts
containing
Ru(III)
andRh
(III)p
articles
mdashAlkaneo
xidatio
n[132]
1996
Goldsupp
ortedon
ZnOandTiO
2Cop
recipitatio
namp
Deposition
-precipitatio
nCa
rbon
mon
oxideo
xidatio
n[133]
1996
Au-TiO
2Incipientw
etness
impregnatio
nCa
rbon
mon
oxideo
xidatio
n[134]
1995
Bism
uthprom
oted
palladium
catalysts
Ionexchange
Glucose
oxidation
[42]
Journal of Nanomaterials 7
HO HO
OOH
OHOH
OH OH
OHOH
OH
OH O
Glucose Gluconic acid
Catalysts
Figure 2 Conversion of glucose to gluconic acid
Si
ClCl Cl
H
trimethyl(phenyl)silane Tetramethylsilane Trichlorosilane
Si CH3
CH3
CH3
Si CH3
CH3
CH3
H3C
Scheme 1
H OH
Dimethylphenylsilane Dimethylphenylsilane
THF RTSi Si
CH3
CH3 CH3
CH3
+ H2O + H2
AuSiO2
Scheme 2
without any supporting materials [42] On the other handbismuth on palladium or PtPd on carbon supports demon-strated high selectivity and stability and excellent conversionrate overcoming the limitations of the heavy metal supportsSome features such as catalyst type and the role of bismuthsupport are still a disputed issue [42]
Prati and Rossi (1997) [43] studied the oxidation of12-diols and found excellent selectivity with gold catalystover platinum and palladium catalysts The gold catalystshowed unusual selectivity in the oxidation of alcohol to itscorresponding carboxylates whereas Pd or Pt showed lowerselectivity to oxidize ethane-12-diol From this observationthey also concluded that Au is less sensitive to overoxidationandor self-poisoning than Pd or Pt Gold clusters andnanoparticles (NPs) deposited on the metal oxide surfacesuch as Al
2O3and ZrO
2demonstrated unexpected catalytic
activity in the oxidation of glucose with better turnover fre-quency (TOF reaction rate per Au atom surface) In additionto carbon andmetal oxide supports some inorganic polymerssuch as silica could be used as catalytic supports for smallAu nanoparticles (gt10 nm in diameter) [43] The catalyticeffect of Au nanoparticles (25 nm) held by polymer gelwas demonstrated by Ishida et al [44] Polymer supportedAuNPs exhibited higher catalytic performance than AuC inthe oxidation of primary alcohols such as benzyl alcohol tobenzaldehyde in absence of base [45] The catalytic activityof various catalysts for glucose oxidation is summarized inTable 3
32 Selective Oxidation of Silanes to Silanols Silane is aninorganic compound having the silicon atom with chemical
formula SiH4 It is a colorless flammable gas with a sharp
and repulsive smell somewhat similar to that of acetic acidSilane has interest as a precursor of silicon metal Silanemay also be referred to many compounds containing sili-con such as trichlorosilane (SiHCl
3) trimethyl(phenyl)silane
(PhSi(CH3)3) and tetramethylsilane (Si(CH
3)4) (Scheme 1)
The oxidation of silane to corresponding silanols (asfor example dimethylphenylsilane to dimethylphenylsilanolScheme 2) is a key reaction to manufacture building blocksfor the synthesis of silica based polymers [46] and nucle-ophilic couplers in organic synthesis In the past silanolssynthesis was often carried out by stoichiometric oxidationof organosilanes hydrolysis of halosilanes or alkali treat-ment of siloxanes which incurred environmental hazards Incontrast the catalytic oxidation of silanes with water is anecofriendly process since it produces silanols with high selec-tivity producing only hydrogen as a by-product Supportedgold nanoparticles have shown higher catalytic activity andselectivity on silane oxidation over other transition metalcatalysts [47] Mitsudome et al [48] oxidized aliphatic silanesto silanols using hydroxyapatite supported AuNPs in waterat 80∘C Nanoporous gold also showed high reactivity andselectivity towards silanes in acetone at room temperature[49]
Recently John et al [50] have synthesized carbon nano-tube-supported gold nanoparticles which showed turnoverfrequency (TOF) of 18000 hminus1 for silane oxidation in tetrahy-drofuran (THF) at room temperature However the prepa-ration of Au CNT (carbon nanotube) hybrids involved amultistep layer-by-layer assembly which needed expensivereagents which have limited its practicability Li et al [47]
8 Journal of Nanomaterials
Table3Oxidatio
nof
glucoseb
yvario
uscatalysts
Nam
eofcatalysts
Preparationmetho
dRe
actio
ncond
ition
Mainprod
uct
Selectivity
()Re
ferences
SubstrateOxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)
pHSolvent
Goldnano
particleso
ncellu
lose
Deposition
-redu
ction
O2
mdash60
95Water
Gluconica
cid
mdash[41]
AuA
l 2O3
Deposition
-precipitatio
nO
27
6090
Water
Gluconica
cid
97[79]
AuC
Catio
nica
dsorption
O2
760
90Water
Gluconica
cid
97[79]
Au-PdC
Impregnatio
nO
220
5092
5mdash
Gluconica
cid
mdash[103]
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
H2O
240
90mdash
Sodium
D-gluconate
99[102]
AuC
Goldsol
mdash30
5095
mdashGluconica
cid
45[124]
Nanosized
AuSiO
2Stob
erH
2O2
2430
92Water
Gluconica
cid
80[95]
Pb-TeSiO
2Re
peated
impregnatio
nO
215
6090
mdashGluconica
cid
884
[104]
AuPtb
imetallic
nano
particle
Vacuum
drying
O2
260
95mdash
Gluconica
cid
mdash[80]
Journal of Nanomaterials 9
Table 4 Comparison of supported gold catalysts for the oxidation of triethylsilane [47]
Catalysts Reaction condition Conversion rate () Yield ()Substrate Solvent Reaction temperature Time (min) Ausubstrate (mol)
AuSiO2
Triethylsilane
Water 25∘C 3 04 99 99AuTiO2 Water 25∘C 3 04 81 81AuFe2O3 Water 25∘C 3 04 36 36AuZnO Water 25∘C 3 04 89 89AuCeO2 Water 25∘C 3 04 98 98
Catalyst
Decomposition
H2 + O2 H2O2
2H2O2
H2O + 12O2
Hydrogenation H2
Scheme 3 Hydrogen peroxide formation hydrogenation and decomposition
prepared silica supported gold catalysts for the selectiveoxidation of silanes However they observed that silicasupported gold catalysts aremore active than reducible oxides(TiO2 Fe2O3 CeO
2 etc) supported AuNPs Highly dis-
persed silica supported gold catalysts override the reducibleoxides supported AuNPs due to superior adsorption of silanesubstrate on silica support Surprisingly for the oxidationof dimethylphenylsilane in THF at room temperature theAuSiO
2catalyst afforded a TOF of 59400 hminus1 which is the
highest TOF reported to dateThe other oxide supported gold catalysts such as
AuTiO2 AuZnO and AuFe
2O3
were less active thanAuSiO
2 and they afforded a maximum conversion of 90
However the activity of AuCeO2catalyst was very similar to
the AuSiO2catalyst (Table 4)
33 Oxidation of Hydrogen to Hydrogen Peroxide (H2O2)
H2O2is an essential chemical which has long been used
mainly as strong oxidant in various oxidative reactions andbleaching agent as well as a disinfectant It is a green oxidantsince its sole by-product is water In the current decades alot of attention has been paid to the green catalysts and greenchemicals to ensure safety issues in health and environmentIndustries have been using supported Pd catalysts for morethan 90 years for the direct synthesis of H
2O2from H
2and
O2 However the synthesized H
2O2is unstable and under-
goes low-temperature decomposition or hydrogenation towater (Scheme 3) [51] Recently Edwards et al [52] usedAu-catalysts synthesized via coprecipitation or deposition-precipitation method and found very low H
2O2conversion
rateThey also observed that the addition of Au to Pd catalystsby impregnation enhances H
2O2formation They compared
five different catalyst supports namely Al2O3 Fe2O3 TiO2
SiO2
and carbon and found the high conversion withcarbon-supported Au-Pd (Au-PdC)
In 2010 Song et al [53] observed that KMnO4treated
activated carbon in an acidic solution enhances H2O2pro-
duction (78) from hydroxylamine due to the creation ofsurface active quinoid species during oxidation Structure
and surface analyses revealed that KMnO4treatment pro-
duced more phenolic but less carboxylic groups on theactivated carbon under acidic condition confirming thecrucial role of the quinoid groups It was also proposed thatthe quinoid groups served as electron acceptors and redoxmediators in the formation of H
2O2[53]
34 Carbon Monoxide (CO) Oxidation In the last decadeCOoxidation has become an important research area becauseof its involvement in a number of processes such asmethanolsynthesis water gas shift reaction carbon dioxide lasersand automotive exhaust controls [54] Carbon monoxide isa lethal gas for animal life and toxic to the environment[55] The oxidation of CO is a difficult process and hencea highly active oxidation catalyst is required for its efficientremoval from the environment [55] In the past the gold wasconsidered to be inert for CO oxidation [56]
However Haruta et al [57] demonstrated that highlydispersed gold prepared on various metal oxide supportsby coprecipitation and deposition-precipitation methods ishighly active in CO oxidation even below 0∘C temperatureThey found that catalytic performance significantly dependson the catalysts preparation methods and the highest activitywas demonstrated by TiO
2supported gold or platinum
catalysts prepared by deposition-precipitation (DP)The goldcatalysts prepared by photodeposition (PD) and impregna-tion (IMP) methods were less active than those preparedby deposition-precipitation This is because the catalystsprepared by DP method contain higher loading of Au(gt2wt) on smaller particles and are with better dispersionCollectively these features enable the catalyst to show higheractivity oxidizingsim100ofCOat temperatures belowminus20∘CIn 1997 Yuan et al [58] synthesized highly active goldcatalysts for CO oxidation simply by grafting Au-phosphinecomplexes (AuL
3NO3or Au
9L8(NO3)3 L = PPh
3) onto
precipitated Ti(OH)4surfaces This Au-phosphine-Ti(OH)
4
complex was active even below the 0∘C Apart from this Na+ions positively andClminus ions negatively affect the Au-catalyzed
10 Journal of Nanomaterials
C O
OH
C
O
O
O
H
O2
Mx+Mx+
AuIIIAuIIIAu0
O2minus
Figure 3 Plausible mechanism for CO oxidation on oxide supported gold catalyst On the left a CO molecule is chemisorbed onto a lowcoordination number gold atom (yellow sphere) and a hydroxyl ion is moved from the oxide support (pink sphere) to an Au (III) ioncreating an anion vacancy On the right they have reacted to form a carboxylate group and an oxygen molecule occupies the anion vacancyas O2minus (white sphere) This then oxidizes the carboxylate group by abstracting a hydrogen atom forming carbon dioxide and the resultinghydroperoxide ionHO
2
minus then further oxidizes carboxylate species to form another carbon dioxide restoring two hydroxyl ions to the supportsurface completing the catalytic cycle (Adapted with permission from Springer) [145]
O
Catalysts
Propene epoxide
Polyether polyols (66) Propene glycols (30) Propene glycols ether (4)
Polyurethanes or foam Polyesters Solvents
CH3CH=CH2 + O2 + H2CH3CH2ndashCH2 + H2O
Scheme 4 Synthetic products from propene epoxidation reaction
CO oxidation Figure 3 represents the initial stages of COoxidation at the edge of an active gold particle
35 Epoxidation of Propene The oxidation of propene toepoxide is an important reaction for the synthesis of variousindustrial chemicals such as polyether polyols (precursorof polyurethane or foams) propene glycol and propeneglycol ethers (Scheme 4) [59] In the past chlorohydrin andhydroperoxide mediated processes were used for the syn-thesis of propene epoxide Chlorohydrin process producesenvironmentally hazardous chlorinated by-products and thehydroperoxide process is much expensive and producesstyrene and tert-butyl alcohol as by-products Silver catalystswere used in this reaction but poor selectivity and turnoverwere observed [60] However titania supported gold effi-ciently catalyzed the epoxidation reaction at 30ndash120∘C withmore than 90 selectivity in the presence of hydrogen [61]
36 Oxidation of Alcohol The oxidation of alcohols to itscorresponding aldehydes or ketones is a crucial reaction inorganic synthesis Ketones specially acetone are widely usedin the production of various organic as well as fine chemicals[62] Traditional chemical routes use stoichiometric chem-icals such as chromium (VI) reagents dimethyl sulfoxidepermanganates periodates or N-chlorosuccinimide whichare expensive and hazardous Several homogeneous catalystssuch as Pd Cu and Ru are found to selectively catalyzealcohol oxidation However homogeneous catalysis requireshigh pressure oxygen andor organic solvent incurring costand environmental burdens [63] The present ecologicaldeterioration has forced researchers to look for novel andenvironmentally friendly catalytic schemes for the oxidationof alcohol Prati and Porta [64] demonstrated that AuCcatalyst shows higher selectivity toward aldehyde in the oxi-dation of primary alcohols Subsequently Endud and Wong[65] synthesized porous SiSn bimetallic catalyst through
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
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MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
6 Journal of Nanomaterials
Table2Con
tinued
Year
Catalyst
Metho
dof
preparation
Major
applications
References
2009
Nickelsub
stitutedcopp
erchromite
spinels
Cop
recipitatio
nAlkylsubstituted
benzeneo
xidatio
n[9]
2007
Goldcatalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[115]
2007
MCM
-48molecular
sieve
mod
ified
with
SnCl
2Po
st-synthesis
mod
ificatio
nAlcoh
oloxidation
[65]
2007
CuO-im
pregnatedmesop
orou
ssilica
Impregnatio
nBe
nzeneo
xidatio
n[116]
2006
Supp
ortedgold
catalysts
Deposition
-precipitatio
nAlcoh
oloxidation
[117]
2006
Au-C
uOA
l 2O3PtA
l 2O3catalysts
Deposition
-precipitatio
nim
pregnatio
nProp
enea
ndprop
aneo
xidatio
n[118]
2006
Manganese
containing
mesop
orou
sMCM
-41and
Al-M
CM-41
molecular
sieves
Impregnatio
np-iso
prop
yltolueneo
xidatio
n[119]
2005
Goldcatalysts
mdashAlcoh
oloxidation
[120]
2005
AuC
Immob
ilizatio
nGlucose
oxidation
Alcoh
oloxidation
[64]
2005
Goldim
mob
ilizedmesop
orou
ssilica
Immob
ilizatio
nCy
clohexane
oxidation
[121]
2005
Nitrou
soxide
over
MFI
zeolites
Hydrothermal
Benzeneo
xidatio
n[122]
2005
CoA
PO-5
molecular
sieves
Hydrothermal
Cyclo
hexane
oxidation
[123]
2004
Carbon
-sup
ported
gold
Goldsol
Glucose
oxidation
[124]
2004
Mn-containing
MCM
-41
Impregnatio
nEthylbenzene
oxidation
[72]
2003
CoO119909C
eO2
Cop
recipitaion
Carbon
mon
oxideo
xidatio
n[125]
2002
Goldcatalysts
Immob
ilizatio
nGlucose
oxidation
[126]
2002
Mn(Salen)MCM
-41
mdashOlefin
sepo
xidatio
n[127]
2002
NanostructuredCu
O119909C
eO2
Gas-con
densation
Carbon
mon
oxideo
xidatio
n[128]
2002
Nano-Au
Catalysts
mdashCa
rbon
mon
oxideo
xidatio
n[55]
2001
AuTiO
2Au
TiO
2SiO
2Deposition
-precipitatio
nProp
enee
poxidatio
n[129]
2000
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
yleneo
xidatio
n[130]
1999
Golddispersedon
TS1and
other
titanium-con
tainingsupp
orts
Disp
ersio
nProp
enee
poxidatio
n[131]
1998
Gold-titaniacatalysts
Deposition
-precipitatio
nProp
ylenee
poxidatio
n[61]
1996
Heterop
olycatalysts
containing
Ru(III)
andRh
(III)p
articles
mdashAlkaneo
xidatio
n[132]
1996
Goldsupp
ortedon
ZnOandTiO
2Cop
recipitatio
namp
Deposition
-precipitatio
nCa
rbon
mon
oxideo
xidatio
n[133]
1996
Au-TiO
2Incipientw
etness
impregnatio
nCa
rbon
mon
oxideo
xidatio
n[134]
1995
Bism
uthprom
oted
palladium
catalysts
Ionexchange
Glucose
oxidation
[42]
Journal of Nanomaterials 7
HO HO
OOH
OHOH
OH OH
OHOH
OH
OH O
Glucose Gluconic acid
Catalysts
Figure 2 Conversion of glucose to gluconic acid
Si
ClCl Cl
H
trimethyl(phenyl)silane Tetramethylsilane Trichlorosilane
Si CH3
CH3
CH3
Si CH3
CH3
CH3
H3C
Scheme 1
H OH
Dimethylphenylsilane Dimethylphenylsilane
THF RTSi Si
CH3
CH3 CH3
CH3
+ H2O + H2
AuSiO2
Scheme 2
without any supporting materials [42] On the other handbismuth on palladium or PtPd on carbon supports demon-strated high selectivity and stability and excellent conversionrate overcoming the limitations of the heavy metal supportsSome features such as catalyst type and the role of bismuthsupport are still a disputed issue [42]
Prati and Rossi (1997) [43] studied the oxidation of12-diols and found excellent selectivity with gold catalystover platinum and palladium catalysts The gold catalystshowed unusual selectivity in the oxidation of alcohol to itscorresponding carboxylates whereas Pd or Pt showed lowerselectivity to oxidize ethane-12-diol From this observationthey also concluded that Au is less sensitive to overoxidationandor self-poisoning than Pd or Pt Gold clusters andnanoparticles (NPs) deposited on the metal oxide surfacesuch as Al
2O3and ZrO
2demonstrated unexpected catalytic
activity in the oxidation of glucose with better turnover fre-quency (TOF reaction rate per Au atom surface) In additionto carbon andmetal oxide supports some inorganic polymerssuch as silica could be used as catalytic supports for smallAu nanoparticles (gt10 nm in diameter) [43] The catalyticeffect of Au nanoparticles (25 nm) held by polymer gelwas demonstrated by Ishida et al [44] Polymer supportedAuNPs exhibited higher catalytic performance than AuC inthe oxidation of primary alcohols such as benzyl alcohol tobenzaldehyde in absence of base [45] The catalytic activityof various catalysts for glucose oxidation is summarized inTable 3
32 Selective Oxidation of Silanes to Silanols Silane is aninorganic compound having the silicon atom with chemical
formula SiH4 It is a colorless flammable gas with a sharp
and repulsive smell somewhat similar to that of acetic acidSilane has interest as a precursor of silicon metal Silanemay also be referred to many compounds containing sili-con such as trichlorosilane (SiHCl
3) trimethyl(phenyl)silane
(PhSi(CH3)3) and tetramethylsilane (Si(CH
3)4) (Scheme 1)
The oxidation of silane to corresponding silanols (asfor example dimethylphenylsilane to dimethylphenylsilanolScheme 2) is a key reaction to manufacture building blocksfor the synthesis of silica based polymers [46] and nucle-ophilic couplers in organic synthesis In the past silanolssynthesis was often carried out by stoichiometric oxidationof organosilanes hydrolysis of halosilanes or alkali treat-ment of siloxanes which incurred environmental hazards Incontrast the catalytic oxidation of silanes with water is anecofriendly process since it produces silanols with high selec-tivity producing only hydrogen as a by-product Supportedgold nanoparticles have shown higher catalytic activity andselectivity on silane oxidation over other transition metalcatalysts [47] Mitsudome et al [48] oxidized aliphatic silanesto silanols using hydroxyapatite supported AuNPs in waterat 80∘C Nanoporous gold also showed high reactivity andselectivity towards silanes in acetone at room temperature[49]
Recently John et al [50] have synthesized carbon nano-tube-supported gold nanoparticles which showed turnoverfrequency (TOF) of 18000 hminus1 for silane oxidation in tetrahy-drofuran (THF) at room temperature However the prepa-ration of Au CNT (carbon nanotube) hybrids involved amultistep layer-by-layer assembly which needed expensivereagents which have limited its practicability Li et al [47]
8 Journal of Nanomaterials
Table3Oxidatio
nof
glucoseb
yvario
uscatalysts
Nam
eofcatalysts
Preparationmetho
dRe
actio
ncond
ition
Mainprod
uct
Selectivity
()Re
ferences
SubstrateOxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)
pHSolvent
Goldnano
particleso
ncellu
lose
Deposition
-redu
ction
O2
mdash60
95Water
Gluconica
cid
mdash[41]
AuA
l 2O3
Deposition
-precipitatio
nO
27
6090
Water
Gluconica
cid
97[79]
AuC
Catio
nica
dsorption
O2
760
90Water
Gluconica
cid
97[79]
Au-PdC
Impregnatio
nO
220
5092
5mdash
Gluconica
cid
mdash[103]
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
H2O
240
90mdash
Sodium
D-gluconate
99[102]
AuC
Goldsol
mdash30
5095
mdashGluconica
cid
45[124]
Nanosized
AuSiO
2Stob
erH
2O2
2430
92Water
Gluconica
cid
80[95]
Pb-TeSiO
2Re
peated
impregnatio
nO
215
6090
mdashGluconica
cid
884
[104]
AuPtb
imetallic
nano
particle
Vacuum
drying
O2
260
95mdash
Gluconica
cid
mdash[80]
Journal of Nanomaterials 9
Table 4 Comparison of supported gold catalysts for the oxidation of triethylsilane [47]
Catalysts Reaction condition Conversion rate () Yield ()Substrate Solvent Reaction temperature Time (min) Ausubstrate (mol)
AuSiO2
Triethylsilane
Water 25∘C 3 04 99 99AuTiO2 Water 25∘C 3 04 81 81AuFe2O3 Water 25∘C 3 04 36 36AuZnO Water 25∘C 3 04 89 89AuCeO2 Water 25∘C 3 04 98 98
Catalyst
Decomposition
H2 + O2 H2O2
2H2O2
H2O + 12O2
Hydrogenation H2
Scheme 3 Hydrogen peroxide formation hydrogenation and decomposition
prepared silica supported gold catalysts for the selectiveoxidation of silanes However they observed that silicasupported gold catalysts aremore active than reducible oxides(TiO2 Fe2O3 CeO
2 etc) supported AuNPs Highly dis-
persed silica supported gold catalysts override the reducibleoxides supported AuNPs due to superior adsorption of silanesubstrate on silica support Surprisingly for the oxidationof dimethylphenylsilane in THF at room temperature theAuSiO
2catalyst afforded a TOF of 59400 hminus1 which is the
highest TOF reported to dateThe other oxide supported gold catalysts such as
AuTiO2 AuZnO and AuFe
2O3
were less active thanAuSiO
2 and they afforded a maximum conversion of 90
However the activity of AuCeO2catalyst was very similar to
the AuSiO2catalyst (Table 4)
33 Oxidation of Hydrogen to Hydrogen Peroxide (H2O2)
H2O2is an essential chemical which has long been used
mainly as strong oxidant in various oxidative reactions andbleaching agent as well as a disinfectant It is a green oxidantsince its sole by-product is water In the current decades alot of attention has been paid to the green catalysts and greenchemicals to ensure safety issues in health and environmentIndustries have been using supported Pd catalysts for morethan 90 years for the direct synthesis of H
2O2from H
2and
O2 However the synthesized H
2O2is unstable and under-
goes low-temperature decomposition or hydrogenation towater (Scheme 3) [51] Recently Edwards et al [52] usedAu-catalysts synthesized via coprecipitation or deposition-precipitation method and found very low H
2O2conversion
rateThey also observed that the addition of Au to Pd catalystsby impregnation enhances H
2O2formation They compared
five different catalyst supports namely Al2O3 Fe2O3 TiO2
SiO2
and carbon and found the high conversion withcarbon-supported Au-Pd (Au-PdC)
In 2010 Song et al [53] observed that KMnO4treated
activated carbon in an acidic solution enhances H2O2pro-
duction (78) from hydroxylamine due to the creation ofsurface active quinoid species during oxidation Structure
and surface analyses revealed that KMnO4treatment pro-
duced more phenolic but less carboxylic groups on theactivated carbon under acidic condition confirming thecrucial role of the quinoid groups It was also proposed thatthe quinoid groups served as electron acceptors and redoxmediators in the formation of H
2O2[53]
34 Carbon Monoxide (CO) Oxidation In the last decadeCOoxidation has become an important research area becauseof its involvement in a number of processes such asmethanolsynthesis water gas shift reaction carbon dioxide lasersand automotive exhaust controls [54] Carbon monoxide isa lethal gas for animal life and toxic to the environment[55] The oxidation of CO is a difficult process and hencea highly active oxidation catalyst is required for its efficientremoval from the environment [55] In the past the gold wasconsidered to be inert for CO oxidation [56]
However Haruta et al [57] demonstrated that highlydispersed gold prepared on various metal oxide supportsby coprecipitation and deposition-precipitation methods ishighly active in CO oxidation even below 0∘C temperatureThey found that catalytic performance significantly dependson the catalysts preparation methods and the highest activitywas demonstrated by TiO
2supported gold or platinum
catalysts prepared by deposition-precipitation (DP)The goldcatalysts prepared by photodeposition (PD) and impregna-tion (IMP) methods were less active than those preparedby deposition-precipitation This is because the catalystsprepared by DP method contain higher loading of Au(gt2wt) on smaller particles and are with better dispersionCollectively these features enable the catalyst to show higheractivity oxidizingsim100ofCOat temperatures belowminus20∘CIn 1997 Yuan et al [58] synthesized highly active goldcatalysts for CO oxidation simply by grafting Au-phosphinecomplexes (AuL
3NO3or Au
9L8(NO3)3 L = PPh
3) onto
precipitated Ti(OH)4surfaces This Au-phosphine-Ti(OH)
4
complex was active even below the 0∘C Apart from this Na+ions positively andClminus ions negatively affect the Au-catalyzed
10 Journal of Nanomaterials
C O
OH
C
O
O
O
H
O2
Mx+Mx+
AuIIIAuIIIAu0
O2minus
Figure 3 Plausible mechanism for CO oxidation on oxide supported gold catalyst On the left a CO molecule is chemisorbed onto a lowcoordination number gold atom (yellow sphere) and a hydroxyl ion is moved from the oxide support (pink sphere) to an Au (III) ioncreating an anion vacancy On the right they have reacted to form a carboxylate group and an oxygen molecule occupies the anion vacancyas O2minus (white sphere) This then oxidizes the carboxylate group by abstracting a hydrogen atom forming carbon dioxide and the resultinghydroperoxide ionHO
2
minus then further oxidizes carboxylate species to form another carbon dioxide restoring two hydroxyl ions to the supportsurface completing the catalytic cycle (Adapted with permission from Springer) [145]
O
Catalysts
Propene epoxide
Polyether polyols (66) Propene glycols (30) Propene glycols ether (4)
Polyurethanes or foam Polyesters Solvents
CH3CH=CH2 + O2 + H2CH3CH2ndashCH2 + H2O
Scheme 4 Synthetic products from propene epoxidation reaction
CO oxidation Figure 3 represents the initial stages of COoxidation at the edge of an active gold particle
35 Epoxidation of Propene The oxidation of propene toepoxide is an important reaction for the synthesis of variousindustrial chemicals such as polyether polyols (precursorof polyurethane or foams) propene glycol and propeneglycol ethers (Scheme 4) [59] In the past chlorohydrin andhydroperoxide mediated processes were used for the syn-thesis of propene epoxide Chlorohydrin process producesenvironmentally hazardous chlorinated by-products and thehydroperoxide process is much expensive and producesstyrene and tert-butyl alcohol as by-products Silver catalystswere used in this reaction but poor selectivity and turnoverwere observed [60] However titania supported gold effi-ciently catalyzed the epoxidation reaction at 30ndash120∘C withmore than 90 selectivity in the presence of hydrogen [61]
36 Oxidation of Alcohol The oxidation of alcohols to itscorresponding aldehydes or ketones is a crucial reaction inorganic synthesis Ketones specially acetone are widely usedin the production of various organic as well as fine chemicals[62] Traditional chemical routes use stoichiometric chem-icals such as chromium (VI) reagents dimethyl sulfoxidepermanganates periodates or N-chlorosuccinimide whichare expensive and hazardous Several homogeneous catalystssuch as Pd Cu and Ru are found to selectively catalyzealcohol oxidation However homogeneous catalysis requireshigh pressure oxygen andor organic solvent incurring costand environmental burdens [63] The present ecologicaldeterioration has forced researchers to look for novel andenvironmentally friendly catalytic schemes for the oxidationof alcohol Prati and Porta [64] demonstrated that AuCcatalyst shows higher selectivity toward aldehyde in the oxi-dation of primary alcohols Subsequently Endud and Wong[65] synthesized porous SiSn bimetallic catalyst through
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Polymer ScienceInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CeramicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CompositesJournal of
NanoparticlesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
NanoscienceJournal of
TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MetallurgyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Journal of Nanomaterials 7
HO HO
OOH
OHOH
OH OH
OHOH
OH
OH O
Glucose Gluconic acid
Catalysts
Figure 2 Conversion of glucose to gluconic acid
Si
ClCl Cl
H
trimethyl(phenyl)silane Tetramethylsilane Trichlorosilane
Si CH3
CH3
CH3
Si CH3
CH3
CH3
H3C
Scheme 1
H OH
Dimethylphenylsilane Dimethylphenylsilane
THF RTSi Si
CH3
CH3 CH3
CH3
+ H2O + H2
AuSiO2
Scheme 2
without any supporting materials [42] On the other handbismuth on palladium or PtPd on carbon supports demon-strated high selectivity and stability and excellent conversionrate overcoming the limitations of the heavy metal supportsSome features such as catalyst type and the role of bismuthsupport are still a disputed issue [42]
Prati and Rossi (1997) [43] studied the oxidation of12-diols and found excellent selectivity with gold catalystover platinum and palladium catalysts The gold catalystshowed unusual selectivity in the oxidation of alcohol to itscorresponding carboxylates whereas Pd or Pt showed lowerselectivity to oxidize ethane-12-diol From this observationthey also concluded that Au is less sensitive to overoxidationandor self-poisoning than Pd or Pt Gold clusters andnanoparticles (NPs) deposited on the metal oxide surfacesuch as Al
2O3and ZrO
2demonstrated unexpected catalytic
activity in the oxidation of glucose with better turnover fre-quency (TOF reaction rate per Au atom surface) In additionto carbon andmetal oxide supports some inorganic polymerssuch as silica could be used as catalytic supports for smallAu nanoparticles (gt10 nm in diameter) [43] The catalyticeffect of Au nanoparticles (25 nm) held by polymer gelwas demonstrated by Ishida et al [44] Polymer supportedAuNPs exhibited higher catalytic performance than AuC inthe oxidation of primary alcohols such as benzyl alcohol tobenzaldehyde in absence of base [45] The catalytic activityof various catalysts for glucose oxidation is summarized inTable 3
32 Selective Oxidation of Silanes to Silanols Silane is aninorganic compound having the silicon atom with chemical
formula SiH4 It is a colorless flammable gas with a sharp
and repulsive smell somewhat similar to that of acetic acidSilane has interest as a precursor of silicon metal Silanemay also be referred to many compounds containing sili-con such as trichlorosilane (SiHCl
3) trimethyl(phenyl)silane
(PhSi(CH3)3) and tetramethylsilane (Si(CH
3)4) (Scheme 1)
The oxidation of silane to corresponding silanols (asfor example dimethylphenylsilane to dimethylphenylsilanolScheme 2) is a key reaction to manufacture building blocksfor the synthesis of silica based polymers [46] and nucle-ophilic couplers in organic synthesis In the past silanolssynthesis was often carried out by stoichiometric oxidationof organosilanes hydrolysis of halosilanes or alkali treat-ment of siloxanes which incurred environmental hazards Incontrast the catalytic oxidation of silanes with water is anecofriendly process since it produces silanols with high selec-tivity producing only hydrogen as a by-product Supportedgold nanoparticles have shown higher catalytic activity andselectivity on silane oxidation over other transition metalcatalysts [47] Mitsudome et al [48] oxidized aliphatic silanesto silanols using hydroxyapatite supported AuNPs in waterat 80∘C Nanoporous gold also showed high reactivity andselectivity towards silanes in acetone at room temperature[49]
Recently John et al [50] have synthesized carbon nano-tube-supported gold nanoparticles which showed turnoverfrequency (TOF) of 18000 hminus1 for silane oxidation in tetrahy-drofuran (THF) at room temperature However the prepa-ration of Au CNT (carbon nanotube) hybrids involved amultistep layer-by-layer assembly which needed expensivereagents which have limited its practicability Li et al [47]
8 Journal of Nanomaterials
Table3Oxidatio
nof
glucoseb
yvario
uscatalysts
Nam
eofcatalysts
Preparationmetho
dRe
actio
ncond
ition
Mainprod
uct
Selectivity
()Re
ferences
SubstrateOxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)
pHSolvent
Goldnano
particleso
ncellu
lose
Deposition
-redu
ction
O2
mdash60
95Water
Gluconica
cid
mdash[41]
AuA
l 2O3
Deposition
-precipitatio
nO
27
6090
Water
Gluconica
cid
97[79]
AuC
Catio
nica
dsorption
O2
760
90Water
Gluconica
cid
97[79]
Au-PdC
Impregnatio
nO
220
5092
5mdash
Gluconica
cid
mdash[103]
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
H2O
240
90mdash
Sodium
D-gluconate
99[102]
AuC
Goldsol
mdash30
5095
mdashGluconica
cid
45[124]
Nanosized
AuSiO
2Stob
erH
2O2
2430
92Water
Gluconica
cid
80[95]
Pb-TeSiO
2Re
peated
impregnatio
nO
215
6090
mdashGluconica
cid
884
[104]
AuPtb
imetallic
nano
particle
Vacuum
drying
O2
260
95mdash
Gluconica
cid
mdash[80]
Journal of Nanomaterials 9
Table 4 Comparison of supported gold catalysts for the oxidation of triethylsilane [47]
Catalysts Reaction condition Conversion rate () Yield ()Substrate Solvent Reaction temperature Time (min) Ausubstrate (mol)
AuSiO2
Triethylsilane
Water 25∘C 3 04 99 99AuTiO2 Water 25∘C 3 04 81 81AuFe2O3 Water 25∘C 3 04 36 36AuZnO Water 25∘C 3 04 89 89AuCeO2 Water 25∘C 3 04 98 98
Catalyst
Decomposition
H2 + O2 H2O2
2H2O2
H2O + 12O2
Hydrogenation H2
Scheme 3 Hydrogen peroxide formation hydrogenation and decomposition
prepared silica supported gold catalysts for the selectiveoxidation of silanes However they observed that silicasupported gold catalysts aremore active than reducible oxides(TiO2 Fe2O3 CeO
2 etc) supported AuNPs Highly dis-
persed silica supported gold catalysts override the reducibleoxides supported AuNPs due to superior adsorption of silanesubstrate on silica support Surprisingly for the oxidationof dimethylphenylsilane in THF at room temperature theAuSiO
2catalyst afforded a TOF of 59400 hminus1 which is the
highest TOF reported to dateThe other oxide supported gold catalysts such as
AuTiO2 AuZnO and AuFe
2O3
were less active thanAuSiO
2 and they afforded a maximum conversion of 90
However the activity of AuCeO2catalyst was very similar to
the AuSiO2catalyst (Table 4)
33 Oxidation of Hydrogen to Hydrogen Peroxide (H2O2)
H2O2is an essential chemical which has long been used
mainly as strong oxidant in various oxidative reactions andbleaching agent as well as a disinfectant It is a green oxidantsince its sole by-product is water In the current decades alot of attention has been paid to the green catalysts and greenchemicals to ensure safety issues in health and environmentIndustries have been using supported Pd catalysts for morethan 90 years for the direct synthesis of H
2O2from H
2and
O2 However the synthesized H
2O2is unstable and under-
goes low-temperature decomposition or hydrogenation towater (Scheme 3) [51] Recently Edwards et al [52] usedAu-catalysts synthesized via coprecipitation or deposition-precipitation method and found very low H
2O2conversion
rateThey also observed that the addition of Au to Pd catalystsby impregnation enhances H
2O2formation They compared
five different catalyst supports namely Al2O3 Fe2O3 TiO2
SiO2
and carbon and found the high conversion withcarbon-supported Au-Pd (Au-PdC)
In 2010 Song et al [53] observed that KMnO4treated
activated carbon in an acidic solution enhances H2O2pro-
duction (78) from hydroxylamine due to the creation ofsurface active quinoid species during oxidation Structure
and surface analyses revealed that KMnO4treatment pro-
duced more phenolic but less carboxylic groups on theactivated carbon under acidic condition confirming thecrucial role of the quinoid groups It was also proposed thatthe quinoid groups served as electron acceptors and redoxmediators in the formation of H
2O2[53]
34 Carbon Monoxide (CO) Oxidation In the last decadeCOoxidation has become an important research area becauseof its involvement in a number of processes such asmethanolsynthesis water gas shift reaction carbon dioxide lasersand automotive exhaust controls [54] Carbon monoxide isa lethal gas for animal life and toxic to the environment[55] The oxidation of CO is a difficult process and hencea highly active oxidation catalyst is required for its efficientremoval from the environment [55] In the past the gold wasconsidered to be inert for CO oxidation [56]
However Haruta et al [57] demonstrated that highlydispersed gold prepared on various metal oxide supportsby coprecipitation and deposition-precipitation methods ishighly active in CO oxidation even below 0∘C temperatureThey found that catalytic performance significantly dependson the catalysts preparation methods and the highest activitywas demonstrated by TiO
2supported gold or platinum
catalysts prepared by deposition-precipitation (DP)The goldcatalysts prepared by photodeposition (PD) and impregna-tion (IMP) methods were less active than those preparedby deposition-precipitation This is because the catalystsprepared by DP method contain higher loading of Au(gt2wt) on smaller particles and are with better dispersionCollectively these features enable the catalyst to show higheractivity oxidizingsim100ofCOat temperatures belowminus20∘CIn 1997 Yuan et al [58] synthesized highly active goldcatalysts for CO oxidation simply by grafting Au-phosphinecomplexes (AuL
3NO3or Au
9L8(NO3)3 L = PPh
3) onto
precipitated Ti(OH)4surfaces This Au-phosphine-Ti(OH)
4
complex was active even below the 0∘C Apart from this Na+ions positively andClminus ions negatively affect the Au-catalyzed
10 Journal of Nanomaterials
C O
OH
C
O
O
O
H
O2
Mx+Mx+
AuIIIAuIIIAu0
O2minus
Figure 3 Plausible mechanism for CO oxidation on oxide supported gold catalyst On the left a CO molecule is chemisorbed onto a lowcoordination number gold atom (yellow sphere) and a hydroxyl ion is moved from the oxide support (pink sphere) to an Au (III) ioncreating an anion vacancy On the right they have reacted to form a carboxylate group and an oxygen molecule occupies the anion vacancyas O2minus (white sphere) This then oxidizes the carboxylate group by abstracting a hydrogen atom forming carbon dioxide and the resultinghydroperoxide ionHO
2
minus then further oxidizes carboxylate species to form another carbon dioxide restoring two hydroxyl ions to the supportsurface completing the catalytic cycle (Adapted with permission from Springer) [145]
O
Catalysts
Propene epoxide
Polyether polyols (66) Propene glycols (30) Propene glycols ether (4)
Polyurethanes or foam Polyesters Solvents
CH3CH=CH2 + O2 + H2CH3CH2ndashCH2 + H2O
Scheme 4 Synthetic products from propene epoxidation reaction
CO oxidation Figure 3 represents the initial stages of COoxidation at the edge of an active gold particle
35 Epoxidation of Propene The oxidation of propene toepoxide is an important reaction for the synthesis of variousindustrial chemicals such as polyether polyols (precursorof polyurethane or foams) propene glycol and propeneglycol ethers (Scheme 4) [59] In the past chlorohydrin andhydroperoxide mediated processes were used for the syn-thesis of propene epoxide Chlorohydrin process producesenvironmentally hazardous chlorinated by-products and thehydroperoxide process is much expensive and producesstyrene and tert-butyl alcohol as by-products Silver catalystswere used in this reaction but poor selectivity and turnoverwere observed [60] However titania supported gold effi-ciently catalyzed the epoxidation reaction at 30ndash120∘C withmore than 90 selectivity in the presence of hydrogen [61]
36 Oxidation of Alcohol The oxidation of alcohols to itscorresponding aldehydes or ketones is a crucial reaction inorganic synthesis Ketones specially acetone are widely usedin the production of various organic as well as fine chemicals[62] Traditional chemical routes use stoichiometric chem-icals such as chromium (VI) reagents dimethyl sulfoxidepermanganates periodates or N-chlorosuccinimide whichare expensive and hazardous Several homogeneous catalystssuch as Pd Cu and Ru are found to selectively catalyzealcohol oxidation However homogeneous catalysis requireshigh pressure oxygen andor organic solvent incurring costand environmental burdens [63] The present ecologicaldeterioration has forced researchers to look for novel andenvironmentally friendly catalytic schemes for the oxidationof alcohol Prati and Porta [64] demonstrated that AuCcatalyst shows higher selectivity toward aldehyde in the oxi-dation of primary alcohols Subsequently Endud and Wong[65] synthesized porous SiSn bimetallic catalyst through
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
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MaterialsJournal of
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Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
8 Journal of Nanomaterials
Table3Oxidatio
nof
glucoseb
yvario
uscatalysts
Nam
eofcatalysts
Preparationmetho
dRe
actio
ncond
ition
Mainprod
uct
Selectivity
()Re
ferences
SubstrateOxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)
pHSolvent
Goldnano
particleso
ncellu
lose
Deposition
-redu
ction
O2
mdash60
95Water
Gluconica
cid
mdash[41]
AuA
l 2O3
Deposition
-precipitatio
nO
27
6090
Water
Gluconica
cid
97[79]
AuC
Catio
nica
dsorption
O2
760
90Water
Gluconica
cid
97[79]
Au-PdC
Impregnatio
nO
220
5092
5mdash
Gluconica
cid
mdash[103]
AuA
l 2O3
Incipientw
etness
impregnatio
nGlucose
H2O
240
90mdash
Sodium
D-gluconate
99[102]
AuC
Goldsol
mdash30
5095
mdashGluconica
cid
45[124]
Nanosized
AuSiO
2Stob
erH
2O2
2430
92Water
Gluconica
cid
80[95]
Pb-TeSiO
2Re
peated
impregnatio
nO
215
6090
mdashGluconica
cid
884
[104]
AuPtb
imetallic
nano
particle
Vacuum
drying
O2
260
95mdash
Gluconica
cid
mdash[80]
Journal of Nanomaterials 9
Table 4 Comparison of supported gold catalysts for the oxidation of triethylsilane [47]
Catalysts Reaction condition Conversion rate () Yield ()Substrate Solvent Reaction temperature Time (min) Ausubstrate (mol)
AuSiO2
Triethylsilane
Water 25∘C 3 04 99 99AuTiO2 Water 25∘C 3 04 81 81AuFe2O3 Water 25∘C 3 04 36 36AuZnO Water 25∘C 3 04 89 89AuCeO2 Water 25∘C 3 04 98 98
Catalyst
Decomposition
H2 + O2 H2O2
2H2O2
H2O + 12O2
Hydrogenation H2
Scheme 3 Hydrogen peroxide formation hydrogenation and decomposition
prepared silica supported gold catalysts for the selectiveoxidation of silanes However they observed that silicasupported gold catalysts aremore active than reducible oxides(TiO2 Fe2O3 CeO
2 etc) supported AuNPs Highly dis-
persed silica supported gold catalysts override the reducibleoxides supported AuNPs due to superior adsorption of silanesubstrate on silica support Surprisingly for the oxidationof dimethylphenylsilane in THF at room temperature theAuSiO
2catalyst afforded a TOF of 59400 hminus1 which is the
highest TOF reported to dateThe other oxide supported gold catalysts such as
AuTiO2 AuZnO and AuFe
2O3
were less active thanAuSiO
2 and they afforded a maximum conversion of 90
However the activity of AuCeO2catalyst was very similar to
the AuSiO2catalyst (Table 4)
33 Oxidation of Hydrogen to Hydrogen Peroxide (H2O2)
H2O2is an essential chemical which has long been used
mainly as strong oxidant in various oxidative reactions andbleaching agent as well as a disinfectant It is a green oxidantsince its sole by-product is water In the current decades alot of attention has been paid to the green catalysts and greenchemicals to ensure safety issues in health and environmentIndustries have been using supported Pd catalysts for morethan 90 years for the direct synthesis of H
2O2from H
2and
O2 However the synthesized H
2O2is unstable and under-
goes low-temperature decomposition or hydrogenation towater (Scheme 3) [51] Recently Edwards et al [52] usedAu-catalysts synthesized via coprecipitation or deposition-precipitation method and found very low H
2O2conversion
rateThey also observed that the addition of Au to Pd catalystsby impregnation enhances H
2O2formation They compared
five different catalyst supports namely Al2O3 Fe2O3 TiO2
SiO2
and carbon and found the high conversion withcarbon-supported Au-Pd (Au-PdC)
In 2010 Song et al [53] observed that KMnO4treated
activated carbon in an acidic solution enhances H2O2pro-
duction (78) from hydroxylamine due to the creation ofsurface active quinoid species during oxidation Structure
and surface analyses revealed that KMnO4treatment pro-
duced more phenolic but less carboxylic groups on theactivated carbon under acidic condition confirming thecrucial role of the quinoid groups It was also proposed thatthe quinoid groups served as electron acceptors and redoxmediators in the formation of H
2O2[53]
34 Carbon Monoxide (CO) Oxidation In the last decadeCOoxidation has become an important research area becauseof its involvement in a number of processes such asmethanolsynthesis water gas shift reaction carbon dioxide lasersand automotive exhaust controls [54] Carbon monoxide isa lethal gas for animal life and toxic to the environment[55] The oxidation of CO is a difficult process and hencea highly active oxidation catalyst is required for its efficientremoval from the environment [55] In the past the gold wasconsidered to be inert for CO oxidation [56]
However Haruta et al [57] demonstrated that highlydispersed gold prepared on various metal oxide supportsby coprecipitation and deposition-precipitation methods ishighly active in CO oxidation even below 0∘C temperatureThey found that catalytic performance significantly dependson the catalysts preparation methods and the highest activitywas demonstrated by TiO
2supported gold or platinum
catalysts prepared by deposition-precipitation (DP)The goldcatalysts prepared by photodeposition (PD) and impregna-tion (IMP) methods were less active than those preparedby deposition-precipitation This is because the catalystsprepared by DP method contain higher loading of Au(gt2wt) on smaller particles and are with better dispersionCollectively these features enable the catalyst to show higheractivity oxidizingsim100ofCOat temperatures belowminus20∘CIn 1997 Yuan et al [58] synthesized highly active goldcatalysts for CO oxidation simply by grafting Au-phosphinecomplexes (AuL
3NO3or Au
9L8(NO3)3 L = PPh
3) onto
precipitated Ti(OH)4surfaces This Au-phosphine-Ti(OH)
4
complex was active even below the 0∘C Apart from this Na+ions positively andClminus ions negatively affect the Au-catalyzed
10 Journal of Nanomaterials
C O
OH
C
O
O
O
H
O2
Mx+Mx+
AuIIIAuIIIAu0
O2minus
Figure 3 Plausible mechanism for CO oxidation on oxide supported gold catalyst On the left a CO molecule is chemisorbed onto a lowcoordination number gold atom (yellow sphere) and a hydroxyl ion is moved from the oxide support (pink sphere) to an Au (III) ioncreating an anion vacancy On the right they have reacted to form a carboxylate group and an oxygen molecule occupies the anion vacancyas O2minus (white sphere) This then oxidizes the carboxylate group by abstracting a hydrogen atom forming carbon dioxide and the resultinghydroperoxide ionHO
2
minus then further oxidizes carboxylate species to form another carbon dioxide restoring two hydroxyl ions to the supportsurface completing the catalytic cycle (Adapted with permission from Springer) [145]
O
Catalysts
Propene epoxide
Polyether polyols (66) Propene glycols (30) Propene glycols ether (4)
Polyurethanes or foam Polyesters Solvents
CH3CH=CH2 + O2 + H2CH3CH2ndashCH2 + H2O
Scheme 4 Synthetic products from propene epoxidation reaction
CO oxidation Figure 3 represents the initial stages of COoxidation at the edge of an active gold particle
35 Epoxidation of Propene The oxidation of propene toepoxide is an important reaction for the synthesis of variousindustrial chemicals such as polyether polyols (precursorof polyurethane or foams) propene glycol and propeneglycol ethers (Scheme 4) [59] In the past chlorohydrin andhydroperoxide mediated processes were used for the syn-thesis of propene epoxide Chlorohydrin process producesenvironmentally hazardous chlorinated by-products and thehydroperoxide process is much expensive and producesstyrene and tert-butyl alcohol as by-products Silver catalystswere used in this reaction but poor selectivity and turnoverwere observed [60] However titania supported gold effi-ciently catalyzed the epoxidation reaction at 30ndash120∘C withmore than 90 selectivity in the presence of hydrogen [61]
36 Oxidation of Alcohol The oxidation of alcohols to itscorresponding aldehydes or ketones is a crucial reaction inorganic synthesis Ketones specially acetone are widely usedin the production of various organic as well as fine chemicals[62] Traditional chemical routes use stoichiometric chem-icals such as chromium (VI) reagents dimethyl sulfoxidepermanganates periodates or N-chlorosuccinimide whichare expensive and hazardous Several homogeneous catalystssuch as Pd Cu and Ru are found to selectively catalyzealcohol oxidation However homogeneous catalysis requireshigh pressure oxygen andor organic solvent incurring costand environmental burdens [63] The present ecologicaldeterioration has forced researchers to look for novel andenvironmentally friendly catalytic schemes for the oxidationof alcohol Prati and Porta [64] demonstrated that AuCcatalyst shows higher selectivity toward aldehyde in the oxi-dation of primary alcohols Subsequently Endud and Wong[65] synthesized porous SiSn bimetallic catalyst through
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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MaterialsJournal of
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Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Journal of Nanomaterials 9
Table 4 Comparison of supported gold catalysts for the oxidation of triethylsilane [47]
Catalysts Reaction condition Conversion rate () Yield ()Substrate Solvent Reaction temperature Time (min) Ausubstrate (mol)
AuSiO2
Triethylsilane
Water 25∘C 3 04 99 99AuTiO2 Water 25∘C 3 04 81 81AuFe2O3 Water 25∘C 3 04 36 36AuZnO Water 25∘C 3 04 89 89AuCeO2 Water 25∘C 3 04 98 98
Catalyst
Decomposition
H2 + O2 H2O2
2H2O2
H2O + 12O2
Hydrogenation H2
Scheme 3 Hydrogen peroxide formation hydrogenation and decomposition
prepared silica supported gold catalysts for the selectiveoxidation of silanes However they observed that silicasupported gold catalysts aremore active than reducible oxides(TiO2 Fe2O3 CeO
2 etc) supported AuNPs Highly dis-
persed silica supported gold catalysts override the reducibleoxides supported AuNPs due to superior adsorption of silanesubstrate on silica support Surprisingly for the oxidationof dimethylphenylsilane in THF at room temperature theAuSiO
2catalyst afforded a TOF of 59400 hminus1 which is the
highest TOF reported to dateThe other oxide supported gold catalysts such as
AuTiO2 AuZnO and AuFe
2O3
were less active thanAuSiO
2 and they afforded a maximum conversion of 90
However the activity of AuCeO2catalyst was very similar to
the AuSiO2catalyst (Table 4)
33 Oxidation of Hydrogen to Hydrogen Peroxide (H2O2)
H2O2is an essential chemical which has long been used
mainly as strong oxidant in various oxidative reactions andbleaching agent as well as a disinfectant It is a green oxidantsince its sole by-product is water In the current decades alot of attention has been paid to the green catalysts and greenchemicals to ensure safety issues in health and environmentIndustries have been using supported Pd catalysts for morethan 90 years for the direct synthesis of H
2O2from H
2and
O2 However the synthesized H
2O2is unstable and under-
goes low-temperature decomposition or hydrogenation towater (Scheme 3) [51] Recently Edwards et al [52] usedAu-catalysts synthesized via coprecipitation or deposition-precipitation method and found very low H
2O2conversion
rateThey also observed that the addition of Au to Pd catalystsby impregnation enhances H
2O2formation They compared
five different catalyst supports namely Al2O3 Fe2O3 TiO2
SiO2
and carbon and found the high conversion withcarbon-supported Au-Pd (Au-PdC)
In 2010 Song et al [53] observed that KMnO4treated
activated carbon in an acidic solution enhances H2O2pro-
duction (78) from hydroxylamine due to the creation ofsurface active quinoid species during oxidation Structure
and surface analyses revealed that KMnO4treatment pro-
duced more phenolic but less carboxylic groups on theactivated carbon under acidic condition confirming thecrucial role of the quinoid groups It was also proposed thatthe quinoid groups served as electron acceptors and redoxmediators in the formation of H
2O2[53]
34 Carbon Monoxide (CO) Oxidation In the last decadeCOoxidation has become an important research area becauseof its involvement in a number of processes such asmethanolsynthesis water gas shift reaction carbon dioxide lasersand automotive exhaust controls [54] Carbon monoxide isa lethal gas for animal life and toxic to the environment[55] The oxidation of CO is a difficult process and hencea highly active oxidation catalyst is required for its efficientremoval from the environment [55] In the past the gold wasconsidered to be inert for CO oxidation [56]
However Haruta et al [57] demonstrated that highlydispersed gold prepared on various metal oxide supportsby coprecipitation and deposition-precipitation methods ishighly active in CO oxidation even below 0∘C temperatureThey found that catalytic performance significantly dependson the catalysts preparation methods and the highest activitywas demonstrated by TiO
2supported gold or platinum
catalysts prepared by deposition-precipitation (DP)The goldcatalysts prepared by photodeposition (PD) and impregna-tion (IMP) methods were less active than those preparedby deposition-precipitation This is because the catalystsprepared by DP method contain higher loading of Au(gt2wt) on smaller particles and are with better dispersionCollectively these features enable the catalyst to show higheractivity oxidizingsim100ofCOat temperatures belowminus20∘CIn 1997 Yuan et al [58] synthesized highly active goldcatalysts for CO oxidation simply by grafting Au-phosphinecomplexes (AuL
3NO3or Au
9L8(NO3)3 L = PPh
3) onto
precipitated Ti(OH)4surfaces This Au-phosphine-Ti(OH)
4
complex was active even below the 0∘C Apart from this Na+ions positively andClminus ions negatively affect the Au-catalyzed
10 Journal of Nanomaterials
C O
OH
C
O
O
O
H
O2
Mx+Mx+
AuIIIAuIIIAu0
O2minus
Figure 3 Plausible mechanism for CO oxidation on oxide supported gold catalyst On the left a CO molecule is chemisorbed onto a lowcoordination number gold atom (yellow sphere) and a hydroxyl ion is moved from the oxide support (pink sphere) to an Au (III) ioncreating an anion vacancy On the right they have reacted to form a carboxylate group and an oxygen molecule occupies the anion vacancyas O2minus (white sphere) This then oxidizes the carboxylate group by abstracting a hydrogen atom forming carbon dioxide and the resultinghydroperoxide ionHO
2
minus then further oxidizes carboxylate species to form another carbon dioxide restoring two hydroxyl ions to the supportsurface completing the catalytic cycle (Adapted with permission from Springer) [145]
O
Catalysts
Propene epoxide
Polyether polyols (66) Propene glycols (30) Propene glycols ether (4)
Polyurethanes or foam Polyesters Solvents
CH3CH=CH2 + O2 + H2CH3CH2ndashCH2 + H2O
Scheme 4 Synthetic products from propene epoxidation reaction
CO oxidation Figure 3 represents the initial stages of COoxidation at the edge of an active gold particle
35 Epoxidation of Propene The oxidation of propene toepoxide is an important reaction for the synthesis of variousindustrial chemicals such as polyether polyols (precursorof polyurethane or foams) propene glycol and propeneglycol ethers (Scheme 4) [59] In the past chlorohydrin andhydroperoxide mediated processes were used for the syn-thesis of propene epoxide Chlorohydrin process producesenvironmentally hazardous chlorinated by-products and thehydroperoxide process is much expensive and producesstyrene and tert-butyl alcohol as by-products Silver catalystswere used in this reaction but poor selectivity and turnoverwere observed [60] However titania supported gold effi-ciently catalyzed the epoxidation reaction at 30ndash120∘C withmore than 90 selectivity in the presence of hydrogen [61]
36 Oxidation of Alcohol The oxidation of alcohols to itscorresponding aldehydes or ketones is a crucial reaction inorganic synthesis Ketones specially acetone are widely usedin the production of various organic as well as fine chemicals[62] Traditional chemical routes use stoichiometric chem-icals such as chromium (VI) reagents dimethyl sulfoxidepermanganates periodates or N-chlorosuccinimide whichare expensive and hazardous Several homogeneous catalystssuch as Pd Cu and Ru are found to selectively catalyzealcohol oxidation However homogeneous catalysis requireshigh pressure oxygen andor organic solvent incurring costand environmental burdens [63] The present ecologicaldeterioration has forced researchers to look for novel andenvironmentally friendly catalytic schemes for the oxidationof alcohol Prati and Porta [64] demonstrated that AuCcatalyst shows higher selectivity toward aldehyde in the oxi-dation of primary alcohols Subsequently Endud and Wong[65] synthesized porous SiSn bimetallic catalyst through
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Polymer ScienceInternational Journal of
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CeramicsJournal of
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CompositesJournal of
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International Journal of
Biomaterials
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TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
10 Journal of Nanomaterials
C O
OH
C
O
O
O
H
O2
Mx+Mx+
AuIIIAuIIIAu0
O2minus
Figure 3 Plausible mechanism for CO oxidation on oxide supported gold catalyst On the left a CO molecule is chemisorbed onto a lowcoordination number gold atom (yellow sphere) and a hydroxyl ion is moved from the oxide support (pink sphere) to an Au (III) ioncreating an anion vacancy On the right they have reacted to form a carboxylate group and an oxygen molecule occupies the anion vacancyas O2minus (white sphere) This then oxidizes the carboxylate group by abstracting a hydrogen atom forming carbon dioxide and the resultinghydroperoxide ionHO
2
minus then further oxidizes carboxylate species to form another carbon dioxide restoring two hydroxyl ions to the supportsurface completing the catalytic cycle (Adapted with permission from Springer) [145]
O
Catalysts
Propene epoxide
Polyether polyols (66) Propene glycols (30) Propene glycols ether (4)
Polyurethanes or foam Polyesters Solvents
CH3CH=CH2 + O2 + H2CH3CH2ndashCH2 + H2O
Scheme 4 Synthetic products from propene epoxidation reaction
CO oxidation Figure 3 represents the initial stages of COoxidation at the edge of an active gold particle
35 Epoxidation of Propene The oxidation of propene toepoxide is an important reaction for the synthesis of variousindustrial chemicals such as polyether polyols (precursorof polyurethane or foams) propene glycol and propeneglycol ethers (Scheme 4) [59] In the past chlorohydrin andhydroperoxide mediated processes were used for the syn-thesis of propene epoxide Chlorohydrin process producesenvironmentally hazardous chlorinated by-products and thehydroperoxide process is much expensive and producesstyrene and tert-butyl alcohol as by-products Silver catalystswere used in this reaction but poor selectivity and turnoverwere observed [60] However titania supported gold effi-ciently catalyzed the epoxidation reaction at 30ndash120∘C withmore than 90 selectivity in the presence of hydrogen [61]
36 Oxidation of Alcohol The oxidation of alcohols to itscorresponding aldehydes or ketones is a crucial reaction inorganic synthesis Ketones specially acetone are widely usedin the production of various organic as well as fine chemicals[62] Traditional chemical routes use stoichiometric chem-icals such as chromium (VI) reagents dimethyl sulfoxidepermanganates periodates or N-chlorosuccinimide whichare expensive and hazardous Several homogeneous catalystssuch as Pd Cu and Ru are found to selectively catalyzealcohol oxidation However homogeneous catalysis requireshigh pressure oxygen andor organic solvent incurring costand environmental burdens [63] The present ecologicaldeterioration has forced researchers to look for novel andenvironmentally friendly catalytic schemes for the oxidationof alcohol Prati and Porta [64] demonstrated that AuCcatalyst shows higher selectivity toward aldehyde in the oxi-dation of primary alcohols Subsequently Endud and Wong[65] synthesized porous SiSn bimetallic catalyst through
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Polymer ScienceInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CeramicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CompositesJournal of
NanoparticlesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
NanoscienceJournal of
TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MetallurgyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Journal of Nanomaterials 11
Si Si
Si
MeOMeOMeO
+
OH
OH
OH
OHOH
OH
OH
OH
OH
OH
OH
O
O
O
O
O
OFe
Fe
O
O
O
SiO
H
N
H
Nanohybrid APTMS
Toluene
Ferrocenecarboxaldehyde Fe nanocatalysts on nanohybrid
SiO2A
l 2O3
SiO2A
l 2O3
SiO2Al2O3
SiO2A
l 2O3
SiO2A
l 2O3
NH2NH2 + MeOH
Nanohybrid SiO2Al2O3-APTMS
SiO2Al2O3-APTMS
24h reflux
NH2 +
Figure 4 Synthesis of heterogeneous Fe nanocatalysts by the immobilization of Fe on functionalized SiO2-Al2O3mixed oxide 3-
aminopropyltrimethoxysilane (3-APTMS) Adapted with permission from Elsevier [18]
postsynthesis modification of rice husk ash as Si precursorand SnCl
2as tin source Using TBHP oxidant the tin
modifiedMCM-48 showedmuch selectivity toward aldehydeor ketone in the oxidation of benzyl alcohols [65]
Chaki et al [66] looked into the catalytic activity ofgold by adding silver (5ndash30Ag content) into gold particlesfor aerobic oxidation of alcohols It showed that lt10Agaccelerates the catalytic activity of Au Recently Kidwai andBhardwaj [67] described that gold nanoparticles (AuNP)are highly active in alcohol oxidation with hydrogen perox-ide as oxidant They observed that AuNPs with extendedsurface area exhibit higher catalytic activity over othersAdditionally gold catalyzed reactions are free from chemicalhazards and toxic solvents and produce water as the only sideproduct This methodology was a great contribution towardsthe development of sustainable green chemistry
4 Heterogeneous Catalysts in the Oxidation ofAlkyl Substituted Benzene
In this Section we described various catalysts their syntheticschemes and performance for the oxidation of alkyl substi-tuted benzenes which are an important compound in organicsynthesis
41 Fe Nanocatalysts Habibi et al [18] synthesized Fe nano-catalyst which oxidized alkyl substituted benzene Theyprepared the heterogeneous nano-Fe catalyst on the SiO
2
Al2O3supports through the covalent immobilization of fer-
rocenecarboxaldehyde which acts as iron source (Figure 4)In the presence of tert-butyl hydroperoxide (TBHP) oxi-dant this catalyst produces acetophenone benzaldehydeand benzoic acid from ethylbenzene with 89 selectivity toacetophenone (Scheme 5)
This catalytic scheme provided certain benefits includingthe low cost raw materials commercially available simple
Me
O
H
O
OH
OEthylbenzene
Acetophenone
Benzaldehyde
Benzoic acid
Scheme 5 Products from the catalytic oxidation of ethyl aromaticwith novel Fe nanocatalysts
chemicals and catalysts reusability for the further oxidationof ethylbenzene The side chain carbonyl group is producedby TBHP oxidant without any solvent at a substrateTBHPratio of 1 1 at 50ndash120∘C in a day
This novel Fe nanocatalyst exhibited higher conversionrate (gt84) of ethylbenzene with 90 selectivity towardacetophenone which is the precursor of many products suchas resins chalcones drugs fine chemicals and opticallyactive alcohols The comparative performances of variouscatalysts for alkyl benzene oxidation are given in Table 5
42 Manganese (III) Porphyrin Complexes in the Oxidation ofAlkyl Substituted Benzene Silica boundmanganese (III) por-phyrin complexes [Mn(TMCPP)](TMCPP 5 10 15 20-tet-rakis-(4-methoxycarbonylphenyl)-2123H-porphyrin] selec-tively catalyzes the oxidation of alkyl substituted benzeneto its corresponding ketone Ghiaci et al [68] synthesizedmanganese porphyrin complexes by immobilization onto
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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MaterialsJournal of
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Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
12 Journal of Nanomaterials
Table5Ca
talysts
fora
lkylbenzeneo
xidatio
n
Nam
eofcatalysts
Substrate
Oxidant
Reactio
ntim
e(h)
Reactio
ntemperature
(∘ C)solvent
Preparationmetho
dMainprod
uct
Selectivity
()
References
Fenano
catalysts
onthes
urface
SiO
2Al 2O
3TB
HP
2450mdash
Immob
ilizatio
nAc
etop
heno
ne89
[18]
AgSB
A-15
TBHP
590mdash
Impregnatio
nAc
etop
heno
ne99
[35]
Nickelsub
stitutedCu
chromite
spinel
TBHP
870CH
3CN
Cop
recipitatio
nAc
etop
heno
ne69
[9]
Silicas
uppo
rted
cobalt
NHPI
O2
24100CH
3COOH
Immob
ilizatio
nAc
etop
heno
ne91
[70]
AuSBA
-15
Ethylbenzene
TBHP
3670CH
3CN
Insituim
pregnatio
nAc
etop
heno
ne93
[40]
Mn-containing
MCM
-41U
O2
mdash350
Impregnatio
nAc
etop
heno
ne936
[72]
[Fe(tpa)
(MeC
N) 2](ClO
4)2
O2
2475∘C2-bu
tano
nemdash
Acetop
heno
ne54
[135]
a TPF
PPFeCl
O2
24100mdash
mdashAc
etop
heno
ne828
[18]
FeM
gObNHPI
O2
2025mdash
mdashAc
etop
heno
ne52
[18]
Fe(salen)-
c POM
H2O
25
80CH
3CN
mdashAc
etop
heno
ne100
[18]
a Fe(5101520-te
trakis(pentaflu
orop
henyl))
porphyrin
bN-hydroxyph
thalim
ide
c Kegging
type
polyoxom
etalate(K8
SiW11O39)[17]U=un
washed
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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BioMed Research International
MaterialsJournal of
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Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Journal of Nanomaterials 13
+
N
NN
N
Mn
OH
OHOH
O
OO
O
O
O
O
OMe
MeO
MeO
O
OO
Surface silanol Group of silica
3-Aminopropyltriethoxysilane SF-3-APTS
NaH TMCPP THF reflux
Mn porphyrin complex
(EtO)3Si(CH2)3NH2
Si(CH2)3NH
Si(CH2)3NH2
72h N2 MnCl2middot4H2ODMF 140∘C 4h N2
Figure 5 The synthetic scheme of manganese porphyrin complex by immobilization on silica support (Adapted with permission fromElsevier [68])
silica support This catalyst complex showed high selec-tivity and efficiency toward hydrocarbon oxidation due toits shape selectivity toward substrate and matrix supportthat provided special atmosphere for CndashH oxidation [69]For catalysts synthesis the silica gel was made active athigh temperature (500∘C) followed by modification with 3-aminopropyltriethoxysilane that acts as silica source underinert gas (N
2) atmosphere The details of the preparation of
this catalyst are described elsewhere (Figure 5) The effects ofvarious parameters such as oxidants solvents and tempera-ture on the oxidation of substituted benzene were studied andthe maximum catalysis was obtained with TBHP oxidant at150∘C under solvent free conditions
43 AgSBA-15 Catalysts in the Oxidation of Alkyl SubstitutedBenzene The CndashH bond of alkyl substituted benzene can beselectively oxidized to its corresponding ketones by AgSBA-15 catalysts with TBHP as oxidant Recently Anand et al [35]synthesized the silica supported Ag catalysts by impregnationmethod and found that AgSBA-15 is an environmentallyfriendly catalyst for the breaking of alkyl benzene CndashHbond They used tetraethyl orthosilicate as silica source andsilver nitrate as silver source The schematic of the syntheticscheme is given in Figure 6 and the details could be obtainedfrom bibliography [35] The prepared catalyst showed thebest conversion rate in presence of tert-butyl hydroperoxide
Table 6 Effect of various solvents on the AgSBA-15 catalyzedoxidation of alkyl substituted benzene at 90∘C in presence of 70TBHP oxidant [35]
Solvent Conversion () Selectivity ()Acetophenone 1-phenylethanol
Toluene 92 92 8DMF 15 80 20Acetonitrile 85 86 12Water 65 89 10No solvent 92 99 1
oxidant with 92 and 99 selectivity towards ketone undersolvent free condition (Table 6)
44 Nickel Substituted Copper Chromite Spinels Anotherform of catalysts called nickel substituted copper chromite(Cu2Cr2O5) spinels can efficiently catalyze the oxidation
of alkyl substituted benzene George and Sugunan (2008)[9] synthesized nickel substituted copper chromite spinelsusing copper nitrate nickel nitrate and chromium nitratevia coprecipitation method In the first step a solution ofcopper nickel and chromium nitrate was prepared in waterThe pH of the solution adjusted to 65ndash80 with the stepwiseaddition of 15 ammonium solution under constant stirring
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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CeramicsJournal of
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CompositesJournal of
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
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TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
14 Journal of Nanomaterials
TEOS
Calcination
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
H2O HCl AgNO3
Figure 6 Synthesis of AgSBA-15 catalysts by impregnation method
+ +
Copper nitrate Nickel nitrate Chromium nitrate Solution of copper nickel and chromium nitrate
Adjust pH 65ndash80 by adding 15 ammonium solution
heat
PrecipitantsNickel substituted copperchromite spinels
Figure 7 Synthesis of nickel substituted copper chromite spinels
Table 7 Recipe for the preparation of various nickels substitutedcopper chromite spinels [9]
Catalysts composition (Cu1minus119909
Ni119909Cr2O4) Designation
CuCr2O4 (119909 = 0) CCrCu075Ni025Cr2O4 (119909 = 025) CNCr-1Cu05Ni05Cr2O4 (119909 = 05) CNCr-2Cu025Ni075Cr2O4 (119909 = 075) CNCr-3NiCr2O4 (119909 = 1) NCr
The precipitate was maintained at 70ndash80∘C for 2 h and agedfor 24 h Finally the precipitate was filtered washed anddried at 353K for 24 h and calcined at 923K for 8 h to getthe spinels Figure 7 depicts the complete procedure for thesynthesis of nickel substituted copper chromite spinel Therecipe of George and Sugunan (2008) [9] for the preparationof nickel substituted copper chromite spinels catalyst is givenin Table 7
Catalytic activity of each spinel for the oxidation of ethyl-benzenewas studied in detail [9] and it was found that CNCr-2 type chromite spinel provides the maximum conversionrate (561) with 687 selectivity towards acetophenone(Table 8) under solvent free conditions [9] Nickel substituted
chromites were compared with those simple chromites andthe nickel chromites demonstrated superior activity
45 Silica Supported Cobalt (II) Salen Complex The aero-bic oxidation of alkyl substituted benzene was successfullycarried out over silica supported cobalt (II) salen complexin presence of O
2in N-hydroxyphthalimide (NHPI) solvent
[70] Rajabi et al [70] prepared the silica supported cobaltsalen complexes by chemical modification of di-imine cobaltcomplex using cobalt acetate as a source of cobalt ion(Figure 8) At first Salicylaldehyde was added to the excessamount of absolute MeOH at room temperature and the3-aminopropyltrimethoxysilane was added to the mixtureThe solution turned into yellow color due to the formationof imine which contains a carbon-nitrogen double bond ahydrogen atom (H) or an organic group is attached to thenitrogen The addition of cobalt (II) acetate to the iminecompound allows the new ligands to complex the cobaltPrior to surfacemodification nanoporous silicawas activatedby inserting into concentrated HCl and subsequent washingwith deionized water (Figure 8)
Rajabi et al [70] also investigated the catalytic activityof immobilized cobalt catalysts for ethylbenzene oxidation
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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CompositesJournal of
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International Journal of
Biomaterials
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MaterialsJournal of
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Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Journal of Nanomaterials 15
Table 8 Oxidation of ethylbenzene by nickel substituted copper chromite spinels [9]
Catalysts Conversion () Selectivity ()Acetophenone 1-phenylethanol Others
CCr 329 139 834 27CNCr-1 447 519 464 17CNCr-2 561 687 281 32CNCr-3 555 556 396 48NCr 202 591 194 215Reaction conditions temperature 70∘C time 8 h EB TBHP ratio 1 2 catalyst weight 01 g solvent 10mL acetonitrile [9]
Table 9 Oxidation reaction of ethylbenzene by reused silica supported Co(II) catalysts
Entry Run Temperature (∘C) Selectivity () Yield ()Alcohol Acetophenone
1 First 100 9 91 782 Second 100 10 90 783 Third 100 10 90 774 Fourth 100 10 90 70
+
OH
NH
CHO
OH
N
O
O
N
CoCo
NSi
Si
O
O
N
O
OO
O
OO
Salicylaldehyde 3-Aminopropyltrimethoxysilane Imine compound
Cobalt (II) acetate
Di-imine cobalt complex
Surface modification
NH2(MeO)3Si
(MeO)3Si
(MeO)3Si
Si(MeO)3
SiO2
SiO2
CoSiO2
Figure 8 Preparation of silica supported cobalt (II) catalysts by surface chemical modification Adapted with permission from Elsevier [70]
with O2in N-hydroxyphthalimide and other solvents and
acetic acid was found to be the best solvent The selectivityand the conversion rate were increasedwith temperatureTheheterogeneous catalysts were reused four times and a littlechange in activity was observed (Table 9)
46 Nanosized Gold-Catalysts Materials in nanometer sizeshow properties distinct from their bulk counterpartsbecause nanosized clusters have electronic structures thathave high dense states [71] Biradar and Asefa (2012) [40]described the oxidation of alkyl substituted benzene oversilica supported gold nanoparticles Supported AuNPs wereprepared by in situ impregnation method [40] to keepthe catalyst well dispersed on the support surfaces Briefly
a solution of Pluronic P-123 was added to water andhydrochloric acid Desired amount of TEOS (tetraethoxysi-lane) was added to the aqeous acidic Pluronic P-123 solutionunder stirring The resulting precipitates was subsequentlyfiltered and washed several time under ambient state toget mesostructured SBA-15 For the synthesis of SBA-15supported gold catalysts HAuCl
4solution was made in
ethanolwater (1 4 ratios) andwaswell dispersed on the silicasupport (Figure 9) The lower sized AuNPs demonstratedhigher TON (turnover number) and lower TOF (turnoverfrequency) (Table 10) Solvent effects on oxidation reactionwere studied and acetonitrile appeared to be the best solventIt produced 79 conversion with 93 selectivity towards theketone products
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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CeramicsJournal of
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CompositesJournal of
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International Journal of
Biomaterials
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TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
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Journal of
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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
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Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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BioMed Research International
MaterialsJournal of
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Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
16 Journal of Nanomaterials
Table 10 Oxidation of ethylbenzene by three different types of AuSBA-15 catalysts [40]
Entry Catalystssample(Au average size)
Wt(mmolAug) Conversion () Selectivity () TON TOF (hminus1)
Ketone Alcohol1 SBA-15 mdash sim0 sim0 sim0 sim0 sim0
2 AuSBA-15 catalyst(54 plusmn 12 nm)
108(548 120583molg) 68 94 6 764 23
3 AuSBA-15 catalyst(69 plusmn 17 nm)
386(1960120583molg) 79 93 7 274 8
4 AuSBA-15 catalyst(84 plusmn 23 nm)
456(2315 120583molg) 89 94 6 256 7
Reaction condition substrate ethylbenzene 1mmol oxidant 80 TBHP (aq) 2mmol solvent acetonitrile 10mL catalyst AuSBA-15 sample with 15mgoverall mass reaction temperature 70∘C internal standard chlorobenzene (05mL) reaction time 36 h and reaction atmosphere air [40]
PEO PPO
Pluronic P-123 Pluronic P-123 solution SBA-15 AuSBA-15
TEOSCalcination
HAuCl4H2O HCl
Figure 9 Schematic diagram for the synthesis of SBA-15 supported gold catalysts
MnMn
Cetyl trimethyl ammonium bromide MCM-41
Stirring CalcinationFiltration wash[CH3ndashCOOminus]2 Mn2+
Figure 10 Schematic diagram for the synthesis of Mn containing MCM-41 catalysts
47 Mn-Containing MCM-41 Catalyst for the Vapor PhaseOxidation of Alkyl Substituted Benzene Vapour-phase oxi-dation of alkyl substituted benzene was performed withcarbon dioxide-free air as an oxidant over MnO
2impreg-
nated MCM-41 catalysts [72] Vetrivel and Pandurangan [72]synthesizedMCM-41 on C
16H33(CH3)3N+Brminus templateThe
Mn containing MCM-41 mesoporous molecular sieves wereprepared by impregnating MCM-41 into manganese acetatesolutions under stirring overnight Finally the solution wasfiltered washed evaporated and calcined at a specific tem-perature to obtain Mn containing MCM-41 (Figure 10) Theyalso optimized the reaction conditions by varying reactiontemperature weight hourly space velocity and time onstream They carried out a number of reactions with thesix types of washed and unwashed Mn containing catalystsIn every case acetophenone was the major products whichincrease with the increase of metal content in the catalystsThe high conversion rate to acetophenone was obtained withMn-MCM-41 catalysts with high Mn content The unwashedcatalysts showed higher reactivity than that of washed onedue to the high density of active site in the unwashed catalysts
5 Preparation Method ofSupported Metal Catalysts
A high number of methods have been proposed for the syn-thesis supported heterogeneous metal catalysts [71] Table 11is a summary of the major methods frequently used incatalysts synthesis
6 Concluding Remark
This review provides an extensive overview of the literatureregarding the applications and synthesis of some heteroge-neous catalysts for oxidation catalysis Advantages and dis-advantages of certain candidature support materials are pre-sented Special emphasis is given to heterogeneous catalysisspecially the metal-support synergy The role of appropriatesolvent that codissolves the catalysts and substrate to easethe pretreatment and oxidation process is tabulated for betterunderstanding In line with the goal of industrial processreaction conditioning and utilization of appropriate andcheap catalysts are briefly outlined Future research should
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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CeramicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CompositesJournal of
NanoparticlesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Journal of Nanomaterials 17
Table11M
ajor
metho
dsof
catalysts
synthesis
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Deposition
-precipitatio
n
(a)D
eposition
-precipitatio
nmetho
diseasie
rfor
thes
ynthesisof
vario
ussupp
ortedmetalcatalystcomplexes
inpresence
ofexcess
alkali
(b)Inalkalin
emediathe[Au
(en)
2]3+catio
nsared
epositedon
anionico
xide
(TiO
2Fe
2O3Al 2O
3ZrO
2andCeO
2)surfa
ces
having
high
isoelectricpo
int(PIgt70
0)
(c)F
unctionalizationof
oxides
may
take
partin
ther
eactionas
co-catalystsforthe
enhancem
ento
fthe
catalytic
activ
ity
(d)Itisa
very
good
metho
dforthe
oxidationof
alkanesto
epoxides
(a)Itisa
multistepprocessesfor
thed
eposition
ofmetal
onto
theo
xide
surfa
ce
(b)Itcanno
tintegrateAu
NPs
onmetaloxides
oflow
isoele
ctric
point(IEPsim2)
such
asSiO
2(c)Itislim
itedto
maxim
um1w
tAu
-loading
(d)Itrequiresm
ultip
lewashing
steps
toelim
inate
excesschlorid
e
[40136137]
Cocon
densation
(a)Itsim
ultaneou
slyform
smesostructure
toanchor
gold
(b)Iteasily
form
shexagon
alarrayof
mesop
ores
andmetal
crystalliteso
f3ndash18n
min
diam
eter
(c)Itisa
simplem
etho
dto
insertgold
nano
particleso
ntothe
surfa
ceof
oxides
(d)Itp
ermits
theformationof
particlesinmetallic
state
surrou
nded
bychlorid
eion
sTh
eseC
lminusions
arethe
basic
species
forc
atalystsactiv
ationdu
ringaceton
ylaceton
e(Ac
Ac)
transfo
rmation(cyclizationdehydration)
ingaseou
sstateandalso
actasp
romotersfor
electrontransfe
rtoO
2du
ringNOredu
ction
with
prop
eneinpresence
ofoxygen
(a)Th
esurface
area
ofcatalysts
preparedby
this
metho
dislow
[136138]
Anion
adsorptio
n
(a)A
queous
anions
(sulfatearsenatesand
anionicfun
ctional
grou
psof
biom
olecules)a
readsorbed
onthee
lectric
allycharged
metaloxides
urfaces
(b)O
ptim
umgold
loadingtakesp
lace
at80∘C
(c)Itisa
simplem
etho
dwith
noneed
fore
xpensiv
einstrumentatio
nsandexpertperson
nel
(a)G
oldloadingcann
otexceed
15wt
(b)Itrequiresm
ultip
lewashing
steps
[137139140
]
Catio
nadsorptio
n
(a)C
atalystcan
beprepared
atroom
temperature
toavoid
decompo
sitionof
them
etalcomplex
andredu
ctionof
gold
(b)H
igherloading
ofgold
(3wt
)can
beachieved
andcatio
nadsorptio
nwith
metalleadstosm
allerp
articles(sim2n
m)w
henthe
solutio
nsupp
ortcon
tacttim
eism
oderate(1h
)
(a)IngeneraltheA
uloadingdidno
texceed2wt
[139141]
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
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[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
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TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
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NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Advances in
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BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
18 Journal of Nanomaterials
Table11C
ontin
ued
Metho
dBriefd
escriptio
nLimitatio
nsRe
ferences
Incipientw
etnessim
pregnatio
n
(a)Interactio
nof
gold
precursorsandthes
uppo
rtsurfa
cetakes
placeb
etweentheo
xygenatom
sofM
e 2Au
(acetonylacetone)a
ndtheO
Hgrou
psof
theS
iO2surfa
ceathigh
temperature
(sim300∘C)
(b)S
trong
interactionbetweenthem
etalcatalystandsupp
ort
oxidesTh
uscatalystisno
teasily
lost
(a)Th
echlorides
onsupp
ortp
romotethe
aggregation
ofAu
NPs
andfre
quently
poiso
nthea
ctives
iteso
fthe
catalyst
(b)L
owpH
(lt1)andhigh
temperature
arep
rerequ
isite
(gt300∘C)
Con
tainsh
ighera
mou
ntof
chlorid
eim
purities
(c)Itcanno
tprodu
ceho
mogeneous
andstableparticles
[136137139]
Disp
ersio
n
(a)itisa
nattractiv
emetho
dto
controlthe
aggregationof
AuNPs
(b)P
articlesiz
eisp
reserved
durin
gtheimmob
ilizatio
nste
p(c)P
articlessizec
aneasilybe
controlled
(d)Itish
ighlyselectivea
ndeffi
cient
(a)Itrequirese
xtensiv
ewashing
steps
toremovee
xcess
chlorid
eimpu
rities
[40136]
Chem
icalvapo
rdeposition
(a)S
uppo
rtsa
reevacuatedin
vacuum
at200∘Cfor4
hto
remove
thea
dsorbedwater
(b)IngeneralOMCV
Dmetho
dinvolved
inas
ystem
where
the
prop
ortio
nbetweenthes
ubstr
atea
reaa
ndgasp
hase
volumeg
ets
largersothatthes
urface
reactio
nsho
ldak
eyparameter
(a)Itise
xpensiv
erequ
iresspecialequipm
entandthe
amou
ntof
metalincorporated
bythismetho
dis
somehow
limitedby
pore
volumeo
finertsolid
supp
ort
[142143]
Etching
(a)Itissyntheticmetho
dsfory
olk-shelln
anop
articles
(b)Itise
fficientcheapera
ndsim
plem
etho
d(a)C
atalystsworkon
lyatlowtemperature
[40144]
Journal of Nanomaterials 19
focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
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focus on the synthesis and application of more efficientheterogeneous catalysts as well as synergizing the catalyst costfor large scale synthesis
Conflict of Interests
The authors declare that they have no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors acknowledge the University of Malaya Fund noRP005A-13 AET
References
[1] K Hemalatha G Madhumitha A Kajbafvala N Anupama RSompalle and S Mohana Roopan ldquoFunction of nanocatalystin chemistry of organic compounds revolution an overviewrdquoJournal of Nanomaterials vol 2013 Article ID 341015 23 pages2013
[2] T Mehler W Behnen J Wilken and J Martens ldquoEnantiose-lective catalytic reduction of acetophenone with borane in thepresence of cyclic 120572-amino acids and their corresponding 120573-amino alcoholsrdquo Tetrahedron Asymmetry vol 5 no 2 pp 185ndash188 1994
[3] V N Hasirci ldquoPVNOmdashDVB hydrogels synthesis and charac-terizationrdquo Journal of Applied Polymer Science vol 27 no 1 pp33ndash41 1982
[4] G Newkome and D Fishel ldquoPreparation of hydrazones ace-tophenone hydrazonerdquo Organic Syntheses vol 50 pp 102ndash1021988
[5] R T Blickenstaff W R Hanson S Reddy and R WittldquoPotential radioprotective agentsmdashVI Chalcones benzophe-nones acid hydrazides nitro amines and chloro compoundsRadioprotection of murine intestinal stem cellsrdquo Bioorganic ampMedicinal Chemistry vol 3 no 7 pp 917ndash922 1995
[6] M Ali M Rahman and S B A Hamid ldquoNanoclustered gold apromising green catalysts for the oxidation of alkyl substitutedbenzenesrdquo Advanced Materials Research vol 925 pp 38ndash422014
[7] I Kani and M Kurtca ldquoSynthesis structural characterizationand benzyl alcohol oxidation activity of mononuclear man-ganese(II) complex with 221015840-bipyridine [Mn(bipy)
2(ClO4)2]rdquo
Turkish Journal of Chemistry vol 36 no 6 pp 827ndash840 2012[8] P Gallezot ldquoSelective oxidation with air on metal catalystsrdquo
Catalysis Today vol 37 no 4 pp 405ndash418 1997[9] K George and S Sugunan ldquoNickel substituted copper chromite
spinels preparation characterization and catalytic activity inthe oxidation reaction of ethylbenzenerdquo Catalysis Communica-tions vol 9 no 13 pp 2149ndash2153 2008
[10] S Devika M Palanichamy and V Murugesan ldquoSelectiveoxidation of diphenylmethane to benzophenone over CeAlPO-5 molecular sievesrdquo Chinese Journal of Catalysis vol 33 no 7-8pp 1086ndash1094 2012
[11] G Centi and S Perathoner ldquoCatalysis and sustainable (green)chemistryrdquo Catalysis Today vol 77 no 4 pp 287ndash297 2003
[12] J H Clark and D J Macquarrie ldquoHeterogeneous catalysis inliquid phase transformations of importance in the industrialpreparation of fine chemicalsrdquo Organic Process Research ampDevelopment vol 1 no 2 pp 149ndash162 1997
[13] Y Wang X Wang and M Antonietti ldquoPolymeric graphiticcarbon nitride as a heterogeneous organocatalyst from photo-chemistry to multipurpose catalysis to sustainable chemistryrdquoAngewandte Chemie International Edition vol 51 no 1 pp 68ndash89 2012
[14] D Cole-Hamilton and R Tooze ldquoHomogeneous catalysismdashadvantages and problemsrdquo in Catalyst Separation Recovery andRecycling pp 1ndash8 Springer 2006
[15] N R Shiju andVV Guliants ldquoRecent developments in catalysisusing nanostructured materialsrdquo Applied Catalysis A Generalvol 356 no 1 pp 1ndash17 2009
[16] I Fechete Y Wang and J C Vedrine ldquoThe past present andfuture of heterogeneous catalysisrdquo Catalysis Today vol 189 no1 pp 2ndash27 2012
[17] A Zapf and M Beller ldquoFine chemical synthesis with homoge-neous palladium catalysts examples status and trendsrdquo Topicsin Catalysis vol 19 no 1 pp 101ndash109 2002
[18] D Habibi A R Faraji M Arshadi and J L G FierroldquoCharacterization and catalytic activity of a novel Fe nano-catalyst as efficient heterogeneous catalyst for selective oxida-tion of ethylbenzene cyclohexene and benzylalcoholrdquo Journalof Molecular Catalysis A Chemical vol 372 pp 90ndash99 2013
[19] M R Maurya A Kumar and J Costa Pessoa ldquoVanadiumcomplexes immobilized on solid supports and their use ascatalysts for oxidation and functionalization of alkanes andalkenesrdquo Coordination Chemistry Reviews vol 255 no 19 pp2315ndash2344 2011
[20] A Dhakshinamoorthy M Alvaro and H Garcia ldquoMetal-organic frameworks as heterogeneous catalysts for oxidationreactionsrdquo Catalysis Science and Technology vol 1 no 6 pp856ndash867 2011
[21] Q Yin J M Tan C Besson et al ldquoA fast soluble carbon-freemolecular water oxidation catalyst based on abundant metalsrdquoScience vol 328 no 5976 pp 342ndash345 2010
[22] A Sivaramakrishna P Suman E V Goud et al ldquoRecentprogress in oxidation of n-alkanes by heterogeneous catalysisrdquoResearch and Reviews in Materials Science and Chemistry vol 1no 1 pp 75ndash103 2012
[23] P Sudarsanam L Katta G Thrimurthulu and B M ReddyldquoVapor phase synthesis of cyclopentanone over nanostructuredceria-zirconia solid solution catalystsrdquo Journal of Industrial andEngineering Chemistry vol 19 no 5 pp 1517ndash1524 2013
[24] A Kajbafvala H Ghorbani A Paravar J P Samberg EKajbafvala and S K Sadrnezhaad ldquoEffects of morphology onphotocatalytic performance of Zinc oxide nanostructures syn-thesized by rapidmicrowave irradiationmethodsrdquo Superlatticesand Microstructures vol 51 no 4 pp 512ndash522 2012
[25] K-H Kim and S-K Ihm ldquoHeterogeneous catalytic wet airoxidation of refractory organic pollutants in industrial wastew-aters a reviewrdquo Journal of Hazardous Materials vol 186 no 1pp 16ndash34 2011
[26] A Corma H Garcıa and F X Llabres I Xamena ldquoEngineeringmetal organic frameworks for heterogeneous catalysisrdquo Chemi-cal Reviews vol 110 no 8 pp 4606ndash4655 2010
[27] A Kajbafvala S Zanganeh E Kajbafvala H R Zargar M RBayati and S K Sadrnezhaad ldquoMicrowave-assisted synthesisof narcis-like zinc oxide nanostructuresrdquo Journal of Alloys andCompounds vol 497 no 1-2 pp 325ndash329 2010
[28] M Yoon R Srirambalaji and K Kim ldquoHomochiral metal-organic frameworks for asymmetric heterogeneous catalysisrdquoChemical Reviews vol 112 no 2 pp 1196ndash1231 2012
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
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[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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NanoparticlesJournal of
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Biomaterials
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MaterialsJournal of
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Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
20 Journal of Nanomaterials
[29] K C Gupta A K Sutar and C-C Lin ldquoPolymer-supportedSchiff base complexes in oxidation reactionsrdquo CoordinationChemistry Reviews vol 253 no 13-14 pp 1926ndash1946 2009
[30] A Kumar V P Kumar B P Kumar V Vishwanathan and KV R Chary ldquoVapor phase oxidation of benzyl alcohol overgold nanoparticles supported on mesoporous TiO
2rdquo Catalysis
Letters vol 144 no 8 pp 1450ndash1459 2014[31] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacile
heterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007
[32] S Sreevardhan Reddy B David Raju V Siva Kumar A HPadmasri S Narayanan and K S Rama Rao ldquoSulfonic acidfunctionalized mesoporous SBA-15 for selective synthesis of 4-phenyl-13-dioxanerdquoCatalysis Communications vol 8 no 3 pp261ndash266 2007
[33] D J Kim B C Dunn P Cole et al ldquoEnhancement in thereducibility of cobalt oxides on a mesoporous silica supportedcobalt catalystrdquo Chemical Communications no 11 pp 1462ndash1464 2005
[34] R Burri K-W Jun Y-H Kim J M Kim S-E Park and JS Yoo ldquoCobalt catalyst heterogenized on SBA-15 for p-xyleneoxidationrdquo Chemistry Letters vol 31 no 2 pp 212ndash213 2002
[35] N Anand K H P Reddy G V S Prasad K S RamaRao and D R Burri ldquoSelective benzylic oxidation of alkylsubstituted aromatics to ketones over AgSBA-15 catalystsrdquoCatalysis Communications vol 23 pp 5ndash9 2012
[36] J H Nam Y Y Jang Y U Kwon and J D NamldquoDirect methanol fuel cell Pt-carbon catalysts by using SBA-15nanoporous templatesrdquo Electrochemistry Communications vol6 no 7 pp 737ndash741 2004
[37] M Arsalanfar A A Mirzaei H R Bozorgzadeh A Samimiand R Ghobadi ldquoEffect of support and promoter on the cat-alytic performance and structural properties of the Fe-Co-Mncatalysts for Fischer-Tropsch synthesisrdquo Journal of Industrialand Engineering Chemistry vol 20 no 4 pp 1313ndash1323 2014
[38] A Kajbafvala M R Shayegh M Mazloumi et al ldquoNanostruc-ture sword-like ZnOwires rapid synthesis and characterizationthrough a microwave-assisted routerdquo Journal of Alloys andCompounds vol 469 no 1-2 pp 293ndash297 2009
[39] P J Kropp G W Breton J D Fields J C Tung and B RLoomis ldquoSurface-mediated reactions 8 Oxidation of sulfidesand sulfoxides with tert-butyl hydroperoxide and OXONErdquoJournal of the American Chemical Society vol 122 no 18 pp4280ndash4285 2000
[40] A V Biradar and T Asefa ldquoNanosized gold-catalyzed selectiveoxidation of alkyl-substituted benzenes and n-alkanesrdquo AppliedCatalysis A General vol 435-436 pp 19ndash26 2012
[41] T Ishida H Watanabe T Bebeko T Akita and M HarutaldquoAerobic oxidation of glucose over gold nanoparticles depositedon celluloserdquoApplied Catalysis A General vol 377 no 1 pp 42ndash46 2010
[42] M Besson F Lahmer P Gallezot P Fuertes and G FlecheldquoCatalytic oxidation of glucose on bismuth-promoted palla-dium catalystsrdquo Journal of Catalysis vol 152 no 1 pp 116ndash1211995
[43] L Prati and M Rossi ldquoChemoselective catalytic oxidation ofpolyols with dioxygen on gold supported catalystsrdquo Studies inSurface Science and Catalysis vol 110 pp 509ndash515 1997
[44] T Ishida H Watanabe T Bebeko and M Haruta ldquoAerobicoxidation of glucose over gold nanoparticles deposited on
celluloserdquo Applied Catalysis A General vol 377 no 1-2 pp 42ndash46 2010
[45] T Ishida S Okamoto R Makiyama and M Haruta ldquoAerobicoxidation of glucose and 1-phenylethanol over gold nanoparti-cles directly deposited on ion-exchange resinsrdquo Applied Cataly-sis A General vol 353 no 2 pp 243ndash248 2009
[46] R Murugavel M G Walawalkar M Dan H W Roesky andC N R Rao ldquoTransformations of molecules and secondarybuilding units to materials a bottom-up approachrdquo Accounts ofChemical Research vol 37 no 10 pp 763ndash774 2004
[47] W Li A Wang X Yang Y Huang and T Zhang ldquoAuSiO2as
a highly active catalyst for the selective oxidation of silanes tosilanolsrdquo Chemical Communications vol 48 no 73 pp 9183ndash9185 2012
[48] T Mitsudome A Noujima T Mizugaki K Jitsukawa and KKaneda ldquoSupported gold nanoparticle catalyst for the selectiveoxidation of silanes to silanols in waterrdquo Chemical Communica-tions no 35 pp 5302ndash5304 2009
[49] N Asao Y Ishikawa N Hatakeyama et al ldquoNanostructuredmaterials as catalysts nanoporous-gold-catalyzed oxidation oforganosilanes with waterrdquo Angewandte Chemie vol 49 no 52pp 10093ndash10095 2010
[50] J John E Gravel A Hagege H Li T Gacoin and EDoris ldquoCatalytic oxidation of silanes by carbon nanotube-goldnanohybridsrdquo Angewandte ChemiemdashInternational Edition vol50 no 33 pp 7533ndash7536 2011
[51] P Landon P J Collier A J Papworth C J Kiely and GJ Hutchings ldquoDirect formation of hydrogen peroxide fromH2O2using a gold catalystrdquo Chemical Communications no 18
pp 2058ndash2059 2002[52] J K Edwards AThomas B E Solsona P Landon A F Carley
and G J Hutchings ldquoComparison of supports for the directsynthesis of hydrogen peroxide from H
2and O
2using Au-Pd
catalystsrdquo Catalysis Today vol 122 no 3-4 pp 397ndash402 2007[53] W Song Y Li X Guo J Li X Huang and W Shen ldquoSelective
surface modification of activated carbon for enhancing thecatalytic performance in hydrogen peroxide production byhydroxylamine oxidationrdquo Journal of Molecular Catalysis AChemical vol 328 no 1-2 pp 53ndash59 2010
[54] O A Kirichenko E A Redina N A Davshan et al ldquoPrepara-tion of alumina-supported gold-ruthenium bimetallic catalystsby redox reactions and their activity in preferential CO oxida-tionrdquo Applied Catalysis B Environmental vol 134-135 pp 123ndash129 2013
[55] T V Choudhary C Sivadinarayana C C Chusuei A KDatye J P Fackler Jr and D W Goodman ldquoCO oxi-dation on supported nano-Au catalysts synthesized from a[Au6(PPh
3)6](BF4)2complexrdquo Journal of Catalysis vol 207 no
2 pp 247ndash255 2002[56] M Haruta N Yamada T Kobayashi and S Iijima ldquoGold cata-
lysts prepared by coprecipitation for low-temperature oxidationof hydrogen and of carbon monoxiderdquo Journal of Catalysis vol115 no 2 pp 301ndash309 1989
[57] M Haruta S Tsubota T Kobayashi H Kageyama M J Genetand B Delmon ldquoLow-temperature oxidation of CO over goldsupported on TiO
2 120572-Fe
2O3 and CO
3O4rdquo Journal of Catalysis
vol 144 no 1 pp 175ndash192 1993[58] Y Yuan A P Kozlova K Asakura H Wan K Tsai and Y
Iwasawa ldquoSupported Au catalysts prepared from Au phosphinecomplexes and as-precipitated metal hydroxides characteriza-tion and low-temperature CO oxidationrdquo Journal of Catalysisvol 170 no 1 pp 191ndash199 1997
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Polymer ScienceInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CeramicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CompositesJournal of
NanoparticlesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
NanoscienceJournal of
TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MetallurgyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Journal of Nanomaterials 21
[59] B K Min and C M Friend ldquoHeterogeneous gold-basedcatalysis for green chemistry low-temperature CO oxidationand propene oxidationrdquo Chemical Reviews vol 107 no 6 pp2709ndash2724 2007
[60] T A Nijhuis MMakkee J A Moulijn and BMWeckhuysenldquoThe production of propene oxide catalytic processes andrecent developmentsrdquo Industrial and Engineering ChemistryResearch vol 45 no 10 pp 3447ndash3459 2006
[61] T Hayashi K Tanaka and M Haruta ldquoSelective vapor-phaseepoxidation of propylene overAuTiO
2catalysts in the presence
of oxygen and hydrogenrdquo Journal of Catalysis vol 178 no 2 pp566ndash575 1998
[62] Y-H Kim S-K Hwang J W Kim and Y-S Lee ldquoZirconiasupported ruthenium catalyst for efficient aerobic oxidationof alcohols to aldehyderdquo Industrial amp Engineering ChemistryResearch vol 53 no 31 pp 12548ndash12552 2014
[63] C Y Ma J Cheng H L Wang et al ldquoCharacteristics ofAuHMS catalysts for selective oxidation of benzyl alcohol tobenzaldehyderdquo Catalysis Today vol 158 no 3-4 pp 246ndash2512010
[64] L Prati and F Porta ldquoOxidation of alcohols and sugars usingAuC catalysts part 1 Alcoholsrdquo Applied Catalysis A Generalvol 291 no 1-2 pp 199ndash203 2005
[65] S Endud and K-LWong ldquoMesoporous silicaMCM-48molec-ular sieve modified with SnCl
2in alkaline medium for selective
oxidation of alcoholrdquo Microporous and Mesoporous Materialsvol 101 no 1-2 pp 256ndash263 2007
[66] N K Chaki H Tsunoyama Y Negishi H Sakurai and TTsukuda ldquoEffect of Ag-doping on the catalytic activity ofpolymer-stabilized Au clusters in aerobic oxidation of alcoholrdquoThe Journal of Physical Chemistry C vol 111 no 13 pp 4885ndash4888 2007
[67] M Kidwai and S Bhardwaj ldquoApplication of mobilized goldnanoparticles as sole catalyst for the oxidation of secondaryalcohols into ketonesrdquoApplied Catalysis A General vol 387 no1-2 pp 1ndash4 2010
[68] M Ghiaci F Molaie M E Sedaghat and N DorostkarldquoMetalloporphyrin covalently bound to silica Preparationcharacterization and catalytic activity in oxidation of ethylbenzenerdquo Catalysis Communications vol 11 no 8 pp 694ndash6992010
[69] I N Lykakis and M Orfanopoulos ldquoPhotooxidation of arylalkanes by a decatungstatetriethylsilane system in the presenceof molecular oxygenrdquo Tetrahedron Letters vol 45 no 41 pp7645ndash7649 2004
[70] F Rajabi R Luque J H Clark B Karimi andD J MacQuarrieldquoA silica supported cobalt (II) Salen complex as efficient andreusable catalyst for the selective aerobic oxidation of ethylbenzene derivativesrdquo Catalysis Communications vol 12 no 6pp 510ndash513 2011
[71] A D Banadaki and A Kajbafvala ldquoRecent advances in facilesynthesis of bimetallic nanostructures an overviewrdquo Journal ofNanomaterials vol 2014 Article ID 985948 28 pages 2014
[72] S Vetrivel and A Pandurangan ldquoVapour-phase oxidation ofethylbenzene with air over Mn-containing MCM-41 meso-porous molecular sievesrdquoApplied Catalysis A General vol 264no 2 pp 243ndash252 2004
[73] P Kim Y Kim H Kim I K Song and J Yi ldquoSynthesis andcharacterization of mesoporous alumina for use as a catalystsupport in the hydrodechlorination of 12-dichloropropaneeffect of preparation condition ofmesoporous aluminardquo Journal
of Molecular Catalysis A Chemical vol 219 no 1 pp 87ndash952004
[74] I Mora-Barrantes A Rodrıguez L Ibarra L Gonzalez and JL Valentın ldquoOvercoming the disadvantages of fumed silica asfiller in elastomer compositesrdquo Journal of Materials Chemistryvol 21 no 20 pp 7381ndash7392 2011
[75] G Perot and M Guisnet ldquoAdvantages and disadvantages ofzeolites as catalysts in organic chemistryrdquo Journal of MolecularCatalysis vol 61 no 2 pp 173ndash196 1990
[76] A Nezamzadeh-Ejhieh and S Khorsandi ldquoPhotocatalyticdegradation of 4-nitrophenol with ZnO supported nano-clinoptilolite zeoliterdquo Journal of Industrial and EngineeringChemistry vol 20 no 3 pp 937ndash946 2014
[77] A-N A El-Hendawy ldquoSurface and adsorptive properties ofcarbons prepared from biomassrdquo Applied Surface Science vol252 no 2 pp 287ndash295 2005
[78] Z Z Chowdhury S B A Hamid R Das et al ldquoPreparationof carbonaceous adsorbents from lignocellulosic biomass andtheir use in removal of contaminants from aqueous solutionrdquoBioResources vol 8 no 4 pp 6523ndash6555 2013
[79] I V Delidovich B LMoroz O P Taran et al ldquoAerobic selectiveoxidation of glucose to gluconate catalyzed by AuAl
2O3and
AuC impact of the mass-transfer processes on the overallkineticsrdquo Chemical Engineering Journal vol 223 pp 921ndash9312013
[80] H Zhang and N Toshima ldquoSynthesis of AuPt bimetallicnanoparticles with a Pt-rich shell and their high catalyticactivities for aerobic glucose oxidationrdquo Journal of Colloid andInterface Science vol 394 no 1 pp 166ndash176 2013
[81] L Wang D Yang J Wang Z Zhu and K Zhou ldquoAmbienttemperature COoxidation over gold nanoparticles (14 nm) sup-ported on Mg(OH)
2nanosheetsrdquo Catalysis Communications
vol 36 pp 38ndash42 2013[82] V G Milt S Ivanova O Sanz et al ldquoAuTiO
2supported on
ferritic stainless steel monoliths as CO oxidation catalystsrdquoApplied Surface Science vol 270 pp 169ndash177 2013
[83] S Rohe K Frank A Schaefer et al ldquoCO oxidation onnanoporous gold a combined TPD and XPS study of activecatalystsrdquo Surface Science vol 609 pp 106ndash112 2013
[84] X Huang XWang XWang et al ldquoP123-stabilized Au-Ag alloynanoparticles for kinetics of aerobic oxidation of benzyl alcoholin aqueous solutionrdquo Journal of Catalysis vol 301 pp 217ndash2262013
[85] H Wang W Fan Y He J Wang J N Kondo and T TatsumildquoSelective oxidation of alcohols to aldehydesketones overcopper oxide-supported gold catalystsrdquo Journal of Catalysis vol299 pp 10ndash19 2013
[86] M J Beier B Schimmoeller T W Hansen J E T AndersenS E Pratsinis and J-D Grunwaldt ldquoSelective side-chainoxidation of alkyl aromatic compounds catalyzed by ceriummodified silver catalystsrdquo Journal of Molecular Catalysis AChemical vol 331 no 1-2 pp 40ndash49 2010
[87] XWang B Tang XHuang YMa andZ Zhang ldquoHigh activityof novel nanoporous Pd-Au catalyst for methanol electro-oxidation in alkaline mediardquo Journal of Alloys and Compoundsvol 565 pp 120ndash126 2013
[88] K Kahler M C Holz M Rohe A C van Veen and MMuhler ldquoMethanol oxidation as probe reaction for active sitesinAuZnO andAuTiO
2catalystsrdquo Journal of Catalysis vol 299
pp 162ndash170 2013
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Polymer ScienceInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CeramicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CompositesJournal of
NanoparticlesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
NanoscienceJournal of
TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MetallurgyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
22 Journal of Nanomaterials
[89] G Zhao M Deng Y Jiang H Hu J Huang and Y LuldquoMicrostructured AuNi-fiber catalyst Galvanic reaction prep-aration and catalytic performance for low-temperature gas-phase alcohol oxidationrdquo Journal of Catalysis vol 301 pp 46ndash53 2013
[90] X Bokhimi R Zanella V Maturano and A Morales ldquoNano-crystalline Ag and Au-Ag alloys supported on titania for COoxidation reactionrdquo Materials Chemistry and Physics vol 138no 2-3 pp 490ndash499 2013
[91] Q Ye J Zhao F Huo et al ldquoNanosized Au supported on three-dimensionally ordered mesoporous 120573-MnO
2 highly active cat-
alysts for the low-temperature oxidation of carbon monoxidebenzene and toluenerdquoMicroporous and Mesoporous Materialsvol 172 pp 20ndash29 2013
[92] L Li A Wang B Qiao et al ldquoOrigin of the high activity ofAuFeO
119909for low-temperatureCOoxidation direct evidence for
a redox mechanismrdquo Journal of Catalysis vol 299 pp 90ndash1002013
[93] P R Makgwane and S S Ray ldquoNanosized ruthenium particlesdecorated carbon nanofibers as active catalysts for the oxidationof p-cymene by molecular oxygenrdquo Journal of Molecular Catal-ysis A Chemical vol 373 pp 1ndash11 2013
[94] M Zhang X Zhu X Liang and Z Wang ldquoPreparation ofhighly efficient AuC catalysts for glucose oxidation via novelplasma reductionrdquo Catalysis Communications vol 25 pp 92ndash95 2012
[95] P Bujak P Bartczak and J Polanski ldquoHighly efficient room-temperature oxidation of cyclohexene and d-glucose overnanogold AuSiO
2in waterrdquo Journal of Catalysis vol 295 pp
15ndash21 2012[96] A C Sunil Sekhar K Sivaranjani C S Gopinath and C P
Vinod ldquoA simple one pot synthesis of nano gold-mesoporoussilica and its oxidation catalysisrdquo Catalysis Today vol 198 no 1pp 92ndash97 2012
[97] G Zhan Y Hong V T Mbah et al ldquoBimetallic Au-PdMgOas efficient catalysts for aerobic oxidation of benzyl alcohol agreen bio-reducing preparation methodrdquo Applied Catalysis AGeneral vol 439-440 pp 179ndash186 2012
[98] T Yan DW RedmanW-Y Yu DW Flaherty J A Rodriguezand C B Mullins ldquoCO oxidation on inverse Fe
2O3Au(1 1 1)
model catalystsrdquo Journal of Catalysis vol 294 pp 216ndash222 2012[99] W Li A Wang X Liu and T Zhang ldquoSilica-supported Au-Cu
alloy nanoparticles as an efficient catalyst for selective oxidationof alcoholsrdquoApplied Catalysis A General vol 433-434 pp 146ndash151 2012
[100] V V Costa M Estrada Y Demidova et al ldquoGold nanoparticlessupported on magnesium oxide as catalysts for the aerobicoxidation of alcohols under alkali-free conditionsrdquo Journal ofCatalysis vol 292 pp 148ndash156 2012
[101] J C Bauer G M Veith L F Allard Y Oyola S H Overburyand S Dai ldquoSilica-supported Au-CuO
119909hybrid nanocrystals as
active and selective catalysts for the formation of acetaldehydefrom the oxidation of ethanolrdquo ACS Catalysis vol 2 no 12 pp2537ndash2546 2012
[102] R Saliger N Decker and U Pruszlige ldquoD-Glucose oxidationwith H
2O2on an AuAl
2O3catalystrdquo Applied Catalysis B
Environmental vol 102 no 3-4 pp 584ndash589 2011[103] S Hermans A Deffernez and M Devillers ldquoAu-PdC catalysts
for glyoxal and glucose selective oxidationsrdquo Applied CatalysisA General vol 395 no 1-2 pp 19ndash27 2011
[104] I Witonska M Frajtak and S Karski ldquoSelective oxidation ofglucose to gluconic acid over Pd-Te supported catalystsrdquoAppliedCatalysis A General vol 401 no 1-2 pp 73ndash82 2011
[105] P Wu P Bai Z Lei K P Loh and X S Zhao ldquoGoldnanoparticles supported on functionalized mesoporous silicafor selective oxidation of cyclohexanerdquoMicroporous and Meso-porous Materials vol 141 no 1ndash3 pp 222ndash230 2011
[106] L Hu X Cao J Yang et al ldquoOxidation of benzylic compoundsby gold nanowires at 1 atm O
2rdquo Chemical Communications vol
47 no 4 pp 1303ndash1305 2011[107] H Aliyan R Fazaeli A R Massah H J Naghash and
S Moradi ldquoOxidation of benzylic alcohols with molecularoxygen catalyzed by Cu
32[PMO
12O40]SiO
2rdquo Iranian Journal
of Catalysis vol 1 no 1 pp 19ndash23 2011[108] M Rosu and A Schumpe ldquoOxidation of glucose in suspensions
of moderately hydrophobized palladium catalystsrdquo ChemicalEngineering Science vol 65 no 1 pp 220ndash225 2010
[109] T Benko A Beck O Geszti et al ldquoSelective oxidation ofglucose versus CO oxidation over supported gold catalystsrdquoApplied Catalysis A General vol 388 no 1-2 pp 31ndash36 2010
[110] M Chun Yan Z Mu J J Li et al ldquoMesoporous co3o4and
AUCO3o4catalysts for low-temperature oxidation of trace
ethylenerdquo Journal of the American Chemical Society vol 132 no8 pp 2608ndash2613 2010
[111] H Liu Y Liu Y Li Z Tang and H Jiang ldquoMetal-organicframework supported gold nanoparticles as a highly active het-erogeneous catalyst for aerobic oxidation of alcoholsrdquo Journal ofPhysical Chemistry C vol 114 no 31 pp 13362ndash13369 2010
[112] F Diehl J Barbier Jr D Duprez I Guibard and G MabilonldquoCatalytic oxidation of heavy hydrocarbons over PtAl
2O3
Influence of the structure of the molecule on its reactivityrdquoApplied Catalysis B Environmental vol 95 no 3-4 pp 217ndash2272010
[113] X Yang XWang C Liang et al ldquoAerobic oxidation of alcoholsoverAuTiO
2 an insight on the promotion effect of water on the
catalytic activity of AuTiO2rdquo Catalysis Communications vol 9
no 13 pp 2278ndash2281 2008[114] Q Jiang Y Xiao Z Tan Q-H Li and C-C Guo ldquoAerobic
oxidation of p-xylene overmetalloporphyrin and cobalt acetatetheir synergy andmechanismrdquo Journal ofMolecular Catalysis AChemical vol 285 no 1-2 pp 162ndash168 2008
[115] H Li B Guan W Wang et al ldquoAerobic oxidation of alcohol inaqueous solution catalyzed by goldrdquoTetrahedron vol 63 no 35pp 8430ndash8434 2007
[116] K M Parida and D Rath ldquoStructural properties and catalyticoxidation of benzene to phenol over CuO-impregnated meso-porous silicardquo Applied Catalysis A General vol 321 no 2 pp101ndash108 2007
[117] T Hayashi T Inagaki N Itayama and H Baba ldquoSelective oxi-dation of alcohol over supported gold catalystsmethyl glycolateformation from ethylene glycol andmethanolrdquo Catalysis Todayvol 117 no 1ndash3 pp 210ndash213 2006
[118] A C Gluhoi N Bogdanchikova and B E Nieuwenhuys ldquoTotaloxidation of propene and propane over gold-copper oxide onalumina catalysts comparison with PtAl
2O3rdquo Catalysis Today
vol 113 no 3-4 pp 178ndash181 2006[119] S Vetrivel and A Pandurangan ldquoAerial oxidation of p-
isopropyltoluene over manganese containing mesoporousMCM-41 and Al-MCM-41 molecular sievesrdquo Journal ofMolecular Catalysis A Chemical vol 246 no 1-2 pp 223ndash2302006
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Polymer ScienceInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CeramicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CompositesJournal of
NanoparticlesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
NanoscienceJournal of
TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MetallurgyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Journal of Nanomaterials 23
[120] B Guan D Xing G Cai et al ldquoHighly selective aerobicoxidation of alcohol catalyzed by a Gold(I) complex with ananionic ligandrdquo Journal of the American Chemical Society vol127 no 51 pp 18004ndash18005 2005
[121] K Zhu J Hu and R Richards ldquoAerobic oxidation of cyclo-hexane by gold nanoparticles immobilized upon mesoporoussilicardquo Catalysis Letters vol 100 no 3-4 pp 195ndash199 2005
[122] E J M Hensen Q Zhu R A J Janssen P C M M MagusinP J Kooyman and R A Van Santen ldquoSelective oxidation ofbenzene to phenol with nitrous oxide over MFI zeolites 1 onthe role of iron and aluminumrdquo Journal of Catalysis vol 233no 1 pp 123ndash135 2005
[123] R Zhang Z Qin M Dong G Wang and J Wang ldquoSelectiveoxidation of cyclohexane in supercritical carbon dioxide overCoAPO-5 molecular sievesrdquo Catalysis Today vol 110 no 3-4pp 351ndash356 2005
[124] Y Onal S Schimpf and P Claus ldquoStructure sensitivity andkinetics of D-glucose oxidation toD-gluconic acid over carbon-supported gold catalystsrdquo Journal of Catalysis vol 223 no 1 pp122ndash133 2004
[125] M Kang M W Song and C H Lee ldquoCatalytic carbonmonoxide oxidation over CoO
119909CeO
2composite catalystsrdquo
Applied Catalysis A General vol 251 no 1 pp 143ndash156 2003[126] S Biella L Prati and M Rossi ldquoSelective oxidation of D-
glucose on gold catalystrdquo Journal of Catalysis vol 206 no 2pp 242ndash247 2002
[127] S Xiang Y Zhang Q Xin and C Li ldquoEnantioselective epoxi-dation of olefins catalyzed by Mn (salen)MCM-41 synthesizedwith a new anchoring methodrdquo Chemical Communications no22 pp 2696ndash2697 2002
[128] B Skarman D Grandjean R E Benfield A Hinz A Anders-son and L ReineWallenberg ldquoCarbon monoxide oxidation onnanostructured CuO
119909CeO
2composite particles characterized
by HREM XPS XAS and high-energy diffractionrdquo Journal ofCatalysis vol 211 no 1 pp 119ndash133 2002
[129] G Mul A Zwijnenburg B van der Linden M Makkeeand J A Moulijn ldquoStability and selectivity of AuTiO
2and
AuTiO2SiO2catalysts in propene epoxidation an in situFT-IR
studyrdquo Journal of Catalysis vol 201 no 1 pp 128ndash137 2001[130] E E Stangland K B Stavens R P Andres and W N Delgass
ldquoCharacterization of gold-titania catalysts via oxidation ofpropylene to propylene oxiderdquo Journal of Catalysis vol 191 no2 pp 332ndash347 2000
[131] T A Nijhuis B J Huizinga M Makkee and J A MoulijnldquoDirect epoxidation of propene using gold dispersed on TS-1and other titanium-containing supportsrdquo Industrial and Engi-neering Chemistry Research vol 38 no 3 pp 884ndash891 1999
[132] Y Matsumoto M Asami M Hashimoto and M MisonoldquoAlkane oxidation with mixed addenda heteropoly catalystscontaining Ru(III) and Rh(III)rdquo Journal of Molecular CatalysisA Chemical vol 114 no 1ndash3 pp 161ndash168 1996
[133] F Boccuzzi A Chiorino S Tsubota and M Haruta ldquoFTIRstudy of carbon monoxide oxidation and scrambling at roomtemperature over gold supported on ZnO and TiO
2sdot 2rdquo Journal
of Physical Chemistry vol 100 no 9 pp 3625ndash3631 1996[134] M A Bollinger and M A Vannice ldquoA kinetic and DRIFTS
study of low-temperature carbon monoxide oxidation over Au-TiO2catalystsrdquoApplied Catalysis B Environmental vol 8 no 4
pp 417ndash443 1996[135] S Furukawa Y Hitomi T Shishido and T Tanaka ldquoEfficient
aerobic oxidation of hydrocarbons promoted by high-spin
nonheme Fe(II) complexes without any reductantrdquo InorganicaChimica Acta vol 378 no 1 pp 19ndash23 2011
[136] L-F Gutierrez S Hamoudi and K Belkacemi ldquoSynthesis ofgold catalysts supported on mesoporous silica materials recentdevelopmentsrdquo Catalysts vol 1 no 1 pp 97ndash154 2011
[137] A Hugon N E Kolli and C Louis ldquoAdvances in the prepara-tion of supported gold catalysts mechanism of deposition sim-plification of the procedures and relevance of the elimination ofchlorinerdquo Journal of Catalysis vol 274 no 2 pp 239ndash250 2010
[138] W R Glomm G Oslashye J Walmsley and J Sjoblom ldquoSyn-thesis and characterization of gold nanoparticle-functionalizedordered mesoporous materialsrdquo Journal of Dispersion Scienceand Technology vol 26 no 6 pp 729ndash744 2005
[139] R Zanella S Giorgio C R Henry and C Louis ldquoAlternativemethods for the preparation of gold nanoparticles supported onTiO2rdquo Journal of Physical Chemistry B vol 106 no 31 pp 7634ndash
7642 2002[140] D A Sverjensky and K Fukushi ldquoAnion adsorption on oxide
surfaces inclusion of the water dipole in modeling the electro-statics of ligand exchangerdquoEnvironmental ScienceampTechnologyvol 40 no 1 pp 263ndash271 2006
[141] R Zanella L Delannoy and C Louis ldquoMechanism of depo-sition of gold precursors onto TiO
2during the preparation by
cation adsorption and deposition-precipitationwithNaOH andureardquo Applied Catalysis A General vol 291 no 1-2 pp 62ndash722005
[142] M Okumura S Nakamura S Tsubota T Nakamura MAzuma and M Haruta ldquoChemical vapor deposition of goldon Al
2O3 SiO2 and TiO
2for the oxidation of CO and of H
2rdquo
Catalysis Letters vol 51 no 3-4 pp 53ndash58 1998[143] Y-S Chi H-P Lin and C-Y Mou ldquoCO oxidation over gold
nanocatalyst confined in mesoporous silicardquo Applied CatalysisA General vol 284 no 1-2 pp 199ndash206 2005
[144] J Lee J C Park and H Song ldquoA Nanoreactor framework ofa AuSiO
2yolkshell structure for catalytic reduction of p-
nitrophenolrdquo Advanced Materials vol 20 no 8 pp 1523ndash15282008
[145] D T Thompson ldquoAn overview of gold-catalysed oxidationprocessesrdquo Topics in Catalysis vol 38 no 4 pp 231ndash240 2006
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Polymer ScienceInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CeramicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CompositesJournal of
NanoparticlesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
NanoscienceJournal of
TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MetallurgyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials
Submit your manuscripts athttpwwwhindawicom
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CorrosionInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Polymer ScienceInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CeramicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CompositesJournal of
NanoparticlesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Biomaterials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
NanoscienceJournal of
TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Journal of
NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
CrystallographyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CoatingsJournal of
Advances in
Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Smart Materials Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MetallurgyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
MaterialsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Nano
materials
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofNanomaterials