8/9/2019 Nano Materials Catalyst
http://slidepdf.com/reader/full/nano-materials-catalyst 1/9
© Kimia ITS – HKI Jatim 1
Akta Kimindo Vol. 1 No. 1 Oktober 2005: 1 – 10AKTA KIMIA
INDONESIA
Nanomaterials as catalysts in the production of fine chemicals*)
Halimaton Hamdan1)
Ibnu Sina Institute for Fundamental Science Studies
Universiti Teknologi Malaysia
Skudai, Johor, Malaysia
ABSTRACT
Zeolit and mesomorphous materials are porous materials with windows, channels and cavity
architectures of nanometer dimensions. Large pore zeolites, mesomorphous MCM-41, MCM-48 and silica
aerogels have been synthesized from rice husk. The growing interest in these novel systems is due to thebulk behaviour of these nanostructured materials which can be designed and tailored by controlling their
cluster nanostructures which lead to greatly improved performance. Changes in the molecular properties of
materials at the nanoscale level greatly enhance their physical and chemical properties. The zeolite lattice
may also be used as a host for encapsulated complexes or metallic clusters allowing the control of
nuclearity of these active species. MCM-41, for examples and enzymatic species to from molecular wires,
zeozymes and hybrid catalyst.
ABSTRAK
Zeolit dan mesomorfosa adalah bahan berpori dengan arsitektur jendela, terowongan dan rongga
yang berdimensi nanometer. Zeolit berpori besar, mesomorfosa MCM-41, MCM-48 dan silika aerogel telah
disintesis dari sekam padi. Pertumbuhan yang menarik dari sintesis baru ini adalah struktur bahan yang
berukuran nano dapat didesain dan dibuat melalui pengontrolan kluster struktur nano yang memberikan
kinerja yang sangat luas. Perubahan dalam sifat molekuler bahan pada tingkat skala nano meningkatkansifat fisik dan sifat kimianya. Kisi-kisi zeolit dapat juga digunakan sebagai host (sarang) untuk
membungkus komplek atau kluster logam yang memungkinkan untuk mengontrol keterpusatan spesies
aktif ini, MCM-41 misalnya telah digunakan untuk sarang polimer, komplek logam dan spesies enzim untuk
membentuk kawat, zeoenzim dan katalis hibrida.
INTRODUCTION
An exciting new scientific trend emerged
in the 80’s for exploring zeolites and
mesomorphous materials, as advanced solid-
state materials. Zeolites and mesomorphous
materials or commonly referred as molecular
sieves, are porous materials with nanometer
dimension (0.3–10 nm) windows, channels andcavity architectures. They represent a ‘new
frontier’ of solid-state chemistry with great
opportunities for innovative research and
development.
The most recent efforts is to find several
novel applications which include molecular
electronics, “quantum” dots/chains, zeolite
electrodes, batteries, nonlinear optical materials,
enzyme mimics, chemical sensors, molecular
wires and nanodevices (Frost and Sulivan,
2001).
The growing interest in these novel
systems is due to the bulk behaviour of these
nanostructured materials which can be designed
and tailored by controlling their cluster
nanostructures which lead to greatly improved
performance. In addition, the characteristics of
these nanomaterials could be purposely
engineered by the variation of the chemical
composition, structure and size distribution(Frost and Sulivan, 2001; Barrer, 1982; Breck,
1974; Meier and Olson, 1987 ).
In tandem with numerous research
findings which are continuously being reported by
about 20000 zeolite scientists globally, we have
made some important discoveries that contribute
to the development in the science and
nanotechnology of zeolites and mesomorphous
materials. This paper presents a general review
of our contributions and recent advances in the
design and investigation of these fascinating
family of nanostructured materials.*) Makalah kunci yang disajikan pada Seminar
Nasional Kimia VII, di Surabaya 9 Agustus 20051) Corresponding author
8/9/2019 Nano Materials Catalyst
http://slidepdf.com/reader/full/nano-materials-catalyst 2/9
Hamdan - Nanomaterials as catalysts in the production of fine chemicals
2 © Kimia ITS – HKI Jatim
ZEOLITES AND MESOMORPHOUS MATERIALS
Zeolites are crystalline, hydrated
aluminosilicates with open three-dimensional
framework structures (Barrer, 1982; Breck, 1974)
built of (SiO4)4– and (AlO4)5– tetrahedra linked by
sharing of an oxygen atom, to form regular
intracrystalline cavities and channels of molecular
dimensions. The first natural zeolite molecular
sieve, stilbite, was discovered by Cronstedt in
1756. He named it ‘ zeolitos’ which means boiling
stone, because the mineral appeared to boil when
heated. Since then about 45 natural zeolites have
been identified.
In 1862, St. Claire Deville attempted,
unsuccessfully, to prepare a synthetic zeolite.
Barrer’s pioneering work in the 1940’s
demonstrated that a wide range of zeolites could
be synthesized from aluminosilicate gels (Frost
and Sulivan, 2001; Barrer, 1982). In 1956, Linde
A, the first commercial zeolite was synthesized byBreck (Breck, 1974). In 1962 Mobil Oil introduced
the use of synthetic zeolite X as a cracking
catalyst, followed by the synthesis of the high
silica zeolites beta and ZSM-5. Today at least 150
synthetic zeolites are known.
Mesoporous MCM-41 and aerogels are
nanostructured materials with great potential as
catalyst and nanocomposites. The interest in new
zeolite-like materials or mesomorphous materials
reflects the importance of improving the
performance of zeolites as molecular sieves or
catalysts. The major problem in the zeolite area is
an apparent restriction of pore size to less than0.8 nm. There have been numerous attempts to
incorporate the selectivity and resilience of zeolite
into a structure which has significantly larger pore
size which is capable of processing large
hydrocarbon molecules. With mesoporous solids
for instance, shape selectivity whose effects on
reactants, products and transition states are well
known in microporous systems may be extended
to larger molecules.
STRUCTURAL CHARACTERISTICS
(i) Zeolites
The various types of zeolites are
characterized by the distinct topology of their
three-dimensional framework, the relative content
of silicon and aluminium, the ordering of the
silicon and aluminium atoms in the tetrahedral
sites of the framework and the type and
distribution of cations. The framework topology
and morphology of zeolites contribute to the
remarkable physical and chemical properties of
these microcrystals. Some of the framework
topologies found in zeolites are shown in Figure 1
zeolite A Zeolit Y
ZSM-5 zeolite beta
ferrierite mordenite
Figure 1 : Framework topologies of various zeolites
ii) Mesomorphous MCM-41
In 1992, a new family of silicate
mesoporous materials, designated as M41S, with
exceptionally large uniform pore structures has
been synthesized. Among these materials, the so-
called MCM-41 family which shows a hexagonal
array of uniform mesopores in the range between
1.6 nm and 10 nm as shown in Figure 2. TheMCM-41 structures were found to be constructed
mainly from amorphous inorganic silica walls of
0.9 to 1.2 nm in thickness around surfactant
molecules. The calcined material have specific
surface areas of about 700 m2 per gram. A so-
called liquid crystal templating mechanism in
which surfactant liquid crystal structures serve as
organic templates has been proposed to explain
the formation of such large pore sizes in the
mesoporous materials. Burning off of the organic
material then leaves back the cylindrical pores.
8/9/2019 Nano Materials Catalyst
http://slidepdf.com/reader/full/nano-materials-catalyst 3/9
Akta Kimindo Vol. 1 No. 1 Oktober 2005: 1 – 10
© Kimia ITS – HKI Jatim 3
Figure 2: Schematic representation of the
structure of a MCM-41 phase with an
interpore distance of ≈ 3.5 nm,
amorphous wall structure and hexagonal
pores.
(iii) Silica Aerogel
In a recent issue of Science, aerogel was
rated among the top ten scientific and
technological developments (Nur, et al., 2005).
Aerogels are advanced materials yet are literally
next to nothing. They consists of more than 96%
air and the remaining four percent is a matrix of
silica (Figure 3). Aerogels are unique materials
with pores and properties which are smaller than
the wavelength of light. Aerogel is the lightest
solid material known; only three times the density
of air and has tremendous insulating capability.
Aerogel is a good insulator because of its
large internal surface area. It disperses heat
throughout its complex structure and aerogel
makes possible development of extremely
interesting applications in vacuum and heatinsulation of hot water tanks and boiler,
refrigerators and industrial ovens. A double pane
window filled with a one inch layer of aerogel
provides the same insulating value as 15
standard thermopanes. It is just a question of
time as to when technology and markets offer the
benefits of “translucent” building components
that feature full control of heat performance. A
promising material for translucent roofing is silica
aerogel.
Figure 3: Silica matrix in aerogel
Aerogels are inert, non-toxic, environmentallyfriendly insulation materials and, its superior
performance over other foam materials is finally
being recognized by designers, engineers and
architects. Silica aerogel is a potential substitute
for silicon dioxide, the reigning dielectric. Silica
aerogel offers a better way to keep the
interconnecting wires from shorting across the
narrow dividing space between transistors which
avoid propagation delays and excessive crosstalkand subsequently may double computer speeds.
Ultralow density (ULD) silica aerogels
have been taken on NASA space shuttle missions
to capture high velocity cosmic dust particles.
Furthermore, aerogels are also being used by
NASA to insulate the rover vehicle for the Mars
Pathfinder project in 1997.
Maerogel; a silica aerogel which is
directly prepared from rice husk (Figure 4) is a
nanomaterial of a highly divided state and exhibits
unconventional properties which offers more cost
effective methods of production and application.
Maerogel is more superior in quality than the
current commercial TEOS aerogel. Being an inert,
non-toxic and environmentally friendly amorphous
material, Maerogel possesses established
physico-chemical properties al listed in Table 1
which can be modified for specific applications.
Figure 4: SEM micrograph and photograph of Maerogel
Si OO
Si Si
O O
Si
O Si O
Si
O
SiO OO
SiO O
OH
OH
OH
OH
HO
HO
8/9/2019 Nano Materials Catalyst
http://slidepdf.com/reader/full/nano-materials-catalyst 4/9
Hamdan - Nanomaterials as catalysts in the production of fine chemicals
4 © Kimia ITS – HKI Jatim
0
0.5
1
1.5
2
2.5
3
without
catalyst
10 20 40 80 sec-
AlMCM-
41Catalyst (SiO2:Al2O3)
A m
o u n t o f d e s i r e d
p r o d u c t ( m
m
o l )
Table 1: Physical Properties of Maerogel
NEW DIRECTIONS
Nanostructured Materials
Large pored zeolites, mesomorphous
MCM-41 and silica aerogels are naturally
nanomaterials due to the existence of pores and
crystalline network of nano dimension. Changes in
the molecular properties of materials at the
nanoscale greatly enhance their physical and
chemical properties. Due to its stable and flexible
framework of variable sizes, the zeolite lattice may
also be used as a host for encapsulated
complexes or metallic clusters allowing the control
of nuclearity of these active species and the steric
contraints imposed on the reactants. MCM-41 and
VPI-5, for example, have been used to host
polymer, metal complexes and enzymetic species
to form molecular wires and zeozymes.
(i) Al-MCM-41 catalysts were prepared with
various SiO2:Al2O3 ratios via direct and
secondary syntheses using sodium aluminate as the aluminium source. Structural studies by 27Al
and 29Si MAS NMR spectroscopy indicated that Al
are in the tetrahedral form and located in the
framework. The presence of distorted framework
aluminium was also observed, more significantly
in the secondary aluminated samples. Maximum
amount of Al was incorporated by direct synthesis
with SiO2:Al2O3 ratio of 10 and a calculated Si/Al
ratio of 15.2. Acidity studies using Pyridine
Desorption Measurement and Temperature
Programmed Desorption of Ammonia
(TPD-NH3) show that the acidity of Al-MCM-41
increases with increase in Al incorporation into theMCM-41 framework. The potential of H-Al-MCM-
41; as a heterogeneous catalyst was studied in
the hydroxyalkylation of benzene with propylene
oxide as a model reaction. Gas chromatography
analysis indicates that H-Al-MCM-41 with
SiO2:Al2O3 ratio of 10 demonstrates the highest
catalytic activity with a conversion of benzene and
selectivity of 92.3% and 87.5% respectively. The
formation of 2-phenyl-1-propanol was optimized at
a temperature of 393 K after 24 hours with
propylene oxide to benzene mol ratio of 0.5 using
nitrobenzene as the solvent. The results indicate
that instead of aluminium content, solvent andreactant mole ratio also play a role to give high
conversion and selectivity of 2-phenyl-1-propanol.
(Mohamed, 2005)
Figure 5 27Al MAS NMR spectra of Zeolite A and Al-
MCM-41 samples with various SiO2:Al2O3
ratios
Figure 6 Amount of 2-phenyl-1-propanol (desired
product) (mmol) with various SiO2:Al2O3 ratio at
constant parameter (Temperature: 363 K; Reactant
Mole Ratio: 0.5; Time: 24 hours; Solvent:Nitrobenzene)
Property Maerogel
Apparent density 0.03 g/cm3
Internal Surface Area 800-900 m2 /g
Mean Pore Diameter 20.8 nm
Thermal Tolerance to 500 C, mp > 1200 C
Thermal Conductivity 0.099 Wm-1 K-1
- 0- ppmAl H2O 6
3+
Dir-Al-MCM-
Dir-Al-MCM-
Dir-Al-MCM-
Dir-Al-MCM-
Sec-Al-MCM-41
Zeolite A
- 56
8/9/2019 Nano Materials Catalyst
http://slidepdf.com/reader/full/nano-materials-catalyst 5/9
Akta Kimindo Vol. 1 No. 1 Oktober 2005: 1 – 10
© Kimia ITS – HKI Jatim 5
(ii) The development of heterogeneous
oxidation catalysts which contain metal
complexed Schiff bases such as phthalocyanine,
porphyrin and salen that mimic catalytic activity of
metaloenzyme is of interest. Encapsulated metal
complex, as the guest molecule, into molecular
sieves with suitable pore sizes such as zeolite Y,VPI-5 and MCM-41 as the host, via covalent or
ionic bonding is expected to be as active as those
present in enzyme, structurally and thermally
more stable, remain unchanged during reactions
and give higher conversions (Figure 7).
Figure 7: Metal complex encapsulated molecular sieves
In situ synthesis of Fe(III)-salen and Cu(II)-
salen complexes, Mn(III) complexes based on
diimine and aroylhydrazone ligands in the cavities
of Al-MCM-41, by the flexible ligand method were
attempted with success in our laboratory. The
catalytic activity of the Fe(III)-salen-Al-MCM-41complex was studied in the oxidative
polymerisation of bisphenol-A using aqueous 30%
H2O2 at room temperature.
Cu2+
T=80oC,
air
Table 2. Catalytic tests on polymerization of
bisphenol-Aa
aAll reactions were carried out at room temperature for
3 h: 100 mg catalyst; 5 mmol bisphenol-A; 3.4 mL 30%
H2O2; 10 mL dioxane
X-Ray diffractograms of all samples
demonstrate that the structure of Al-MCM-41 are
still intact after modification process with slightly
decrease in crystallinity. The immobilization of
salen ligand increases the pore diameter and unit
cell parameter of support due to the steric effect.
From DRUV-Vis spectra, it is observed that the
geometry of Table 2. Catalytic tests on
polymerization of bisphenol-Aa
Mn(Salen) and Co(Salen) complexes are
distorted upon encapsulation which can be
evaluated from the splitting of d-d electronic
transition. The main product of benzyl alcohol
oxidation is benzaldehyde and this molecule can
undergo further oxidation to produce benzoic acid.It is observed that the encapsulated Fe(Salen)
catalyst shows the best substrate conversion
followed by Co(Salen) and Mn(Salen).
(iii) Dibenzoylation of benzoyl chloride in the
presence of mesoporous H-Al-MCM-41 forms the
biphenyl 4,4’-dibenzoylbiphenyl (DB) with 100%
selectivity. Catalytic results indicate that samples
with higher Si/Al ratios produced higher yields of
4,4′-dibenzoylbiphenyl. Sample with the highest
Si/Al ratio produced 0.45 µmol 4,4′-dibenzoyl
biphenyl; the highest yield, after 3 hours of reaction. The catalytic test results indicate that
the product yield is influenced and determined by
the presence of both Lewis and Brønsted acid
sites. (Figure 8)
Catalyst
Quantity of
Polybisphenol-
A (g)
Percentage
of reacted
bisphenol-A
Fe(III)-salen(FS)
0.22 19.3
FSAM-40 0.76 66.7
FSAM-60 0.71 62.3
FSAM-120 0.38 33.3
salen
T=140oC,Nitrogen
gas
Cun+
ZEOZIM Cu-salen-Al-MCM-41
8/9/2019 Nano Materials Catalyst
http://slidepdf.com/reader/full/nano-materials-catalyst 6/9
Hamdan - Nanomaterials as catalysts in the production of fine chemicals
6 © Kimia ITS – HKI Jatim
Figure 8: 27Al MAS NMR spectra of (a) SO4-AlMCM-
41, (b) H-AlMCM-41, (c) cal-AlMCM-41 and (d)
SO4-AlMCM-41 after treatment with 1.0 M
methanolic HCl solution.
(iv) Sulphated AlMCM-41 (SO4-AlMCM-41)
mesoporous molecular sieves with SiO2 /Al2O3
ratio=15 was prepared via impregnation of
sulphuric acid on the surface of H-AlMCM-41.
Results of this work (Table 3) demonstrate thatSO4-AlMCM-41 is a solid Brönsted acid and active
towards benzoylation and dibenzoylation of
biphenyl. The production of 4, 4’-DBBP is affected
by the amount of acid site, amount of biphenyl
and 4-PBP. The conversion of biphenyl over H-
AlMCM-41 and sulphuric acid, sulphuric acid, SO4-
AlMCM-41 and sulphated amorphous silica are
83.7, 90.6, 75.0, 94.2 and 22.3%, respectively.
The selectivity towards 4-PBP over H-AlMCM-41,
the mixture of H-AlMCM-41 and sulphuric acid,
sulphuric acid, SO4-AlMCM-41 and sulphated
amorphous silica (SO4-silica) are 83.7, 11.1, 19.3,
83.2 and 22.1%, respectively. The SO4-AlMCM-41which contains octahedral aluminium related to
the presence of Bronsted acid (Figure 8 and 9)
was found to be active towards dibenzoylation of
biphenyl reaction, giving 11.0% of 4, 4’-DBBP
whereas sulphuric acid and H-AlMCM-41 catalyst
which contains both Lewis and Bronsted acid sites
only produced 4.1% of 4, 4’-DBBP
(v) Recently, a novel concept of “phase-
boundary catalysis” (PBC) in the catalysis of
immiscible liquid-liquid reaction system was
proposed. In the PBC system, the bifunctional
particles containing both the hydrophilic andhydrophobic regions, which require neither stirring
nor addition of co-solvent, were placed at the
phase boundary in order to catalyze the reaction.
It is of interest to enhance the activity of PBC
system The activity enhancement of the PBC
system by fluorination was explored. Hydrogen
peroxide was chosen as the oxidizing agent
because it produces only water as the by-product.In addition, it is cheaper and more accessible
than other oxidant.
NaY zeolite was used as the host material
for the phase-boundary catalyst. Titanium
tetraisopropoxide was impregnated from
cyclohexanol solution into NaY zeolite powder to
give Ti-NaY. After that, the mixture was suspended
in toluene solution containing
octadecyltrichlorosilane (OTS). The fluorination
was carried out in 1M ammonium
hexafluorosilicate solution [(NH4)2SiF6] to give
F-PB-NaY. In the epoxidation reaction, 1-octene (4
ml), 30% aqueous H2O2 (1 ml) and the catalyst
powder (50 mg) were placed in a glass tube. The
reaction was performed with or without stirring for
24 hours at ambient temperature.
Wavenumber / cm-1
1640 1600 1560 1520 1480 1440 1400
A b s o r b a n c e / a .
u .
(a)
(b)
Figure 9: The pyridine-FTIR spectra of (a) SO4-
AlMCM-41 and (b) H-AlMCM-41 at 250 oC.
8/9/2019 Nano Materials Catalyst
http://slidepdf.com/reader/full/nano-materials-catalyst 7/9
Akta Kimindo Vol. 1 No. 1 Oktober 2005: 1 – 10
© Kimia ITS – HKI Jatim 7
Table 3: Benzoylation and dibenzoylation of biphenyl with benzoyl chloride over various types of catalysts at
180oC for 24 h.
Catalyst(s) Conversion of BP
(%)
Selectivity towards 4-
PBP (%)
Selectivity
towards 4, 4’-
DBBP (%)
Selectivity
towards others
(%)
H2SO4 a 75.0 35.3 0.0 39.7
H-AlMCM-41 83.7 83.7 0.0 0.0
H2SO4 + H-AlMCM-41 90.6 13.0 1.65 76.0
SO4-AlMCM-41 94.2 83.2 11.0 0.0
SO4-Silica 22.3 22.1 0.0 0.2
a Homogeneous catalyst.
Activity comparison in Table 4 between
phase-boundary catalysts (PB- and F-PB-) and
hydrophilic catalysts (Ti- and F -Ti-) of all catalysts
(Figure 10) on the epoxidation of 1-octene to give
1,2-epoxyoctane indicated that the amphiphilic
catalysts are more feasible for epoxidation. When
the amphiphilic particles are placed at the phase
boundary with the hydrophobic side facing the 1-
octene phase and the hydrophilic side facing the
H2O2 phase, titanium active sites on the catalysts
are in contact with both the octene substrate and
H2O2. This resulted in a continuous supply of H2O2
and alkene substrate to the active sites on theparticles. Fluorine is the most electronegative
element. Being electron deficient, it has a high
tendency and affinity to attract electrons from its
nearby element. Based on this nature, fluorine
which was introduced to the catalyst by
fluorination would draw the electron from titanium
active sites towards the fluorine sites (Ti4+→F-).
Consequently, titanium as the active site for
epoxidation reaction is further activated by
fluorination. Amphiphilic fluorinated Ti-NaY
catalysts showed a remarkable activity
enhancement as observed in the F-PB-NaY
catalyst which gives the highest TON/BET
vi) Titanium containing silica aerogel was
prepared by the sol-gel method. The tetrahedral
titanium is present in low titanium loading, TSA1
(Si:Ti = 200) is responsible in the catalysis of
cyclohexene to 1,2-cyclohexanediol as a major
product in the presence of hydrogen peroxide.
Higher titanium loaded silica aerogel, (TSA2 (Si: Ti
=33) absorbs at 250 nm in UV DRS, suggesting
the presence of [Ti(SiO)3O-] species. Selectivity of
TSA2 is tuneable by changing the loading of the
catalyst in the reaction mixture. TSA1 catalysed
cyclohexene to produce 1,2-cyclohexanediol at
low loading and 2-cyclohexene-1-one when the
loading was doubled.(Figure11)
Table 4: Epoxidation of 1-octene by various modified Ti-NaY catalysts
All reactions were carried out at room temperature for 24 hours with 1-octene (4 ml), 30% H2O2 (1 ml) and catalyst (50mg) with vigorous stirring. The concentration of Ti and OTS = 500 μmol g -1.
Catalyst Epoxide (μmol) BET (m2/g) TON for Ti
TON/BET
( x 10-3)
None 0.0 - - -
Ti-NaY 74.9 718.46 3.0 4.18
PB-NaY 94.1 118.04 3.8 32.19
F-Ti-NaY 111.2 22.37 4.4 196.69
F-PB--NaY 172.5 14.20 6.9 485.92
8/9/2019 Nano Materials Catalyst
http://slidepdf.com/reader/full/nano-materials-catalyst 8/9
Hamdan - Nanomaterials as catalysts in the production of fine chemicals
8 © Kimia ITS – HKI Jatim
Figure 10: Photographs of modified Ti-NaY catalysts: Ti-NaY, OTS-Ti-NaY, F -Ti-NaY, OTS-F -Ti-NaY and TMS-F -Ti- NaY (from
left tto right).
0
10
20
30
40
50
60
70
Alkene Glycol Keton Others
31.3mg
TSA262.5mg
TSA2125mg
TSA2
0
10
20
30
40
50
60
70
Alkene Glycol Keton Others
31.3mgTSA1
62.5mgTSA1
Figure 11: The component percent in the reaction
mixture after reaction using (a) TSA1 and (b) TSA2 as
catalyst
CONCLUDING REMARKS AND FUTURE
OUTLOOK
Several features of the structuralchemistry of zeolites are related to their
importance as sorbents, molecular sieves and
catalysts. Zeolites are potentially very active
catalysts due to the topology of the framework,
shape and size of the pores which can be
modified to accommodate sorbates and impose
shape selective contraints on the products of the
reaction. It is apparent that more applications of
these remarkable zeolite systems will be realised
as our knowledge of the chemistry and structureof the framework continues to grow.
Improvements in the technologies for the
synthesis of zeolites and development of zeolites
with larger pore sizes hold great promise in
better use of the depleting petroleum resources.
Industrial application of aerogel-based
catalyst or catalyst supports have so far been
limited due to the rather expensive method of
preparation and difficulties in reactors operation.
Production of silica aerogel from rice husk does
not only reduce the cost but at the same time
minimise prolonged environmental problem. The
future beneficial use of aerogels in catalysismainly requires tailoring and design of the
surface structure and overcoming the technical
limitations.
REFERENCES
Barrer, R. M. 1982. Hydrothermal Chemistry of
Zeolites. Academic Press, London
Breck, D. W. 1974. Zeolite Molecular Sieves:
Structure, Chemistry and Use. John Wiley
and Sons, London.
8/9/2019 Nano Materials Catalyst
http://slidepdf.com/reader/full/nano-materials-catalyst 9/9
Akta Kimindo Vol. 1 No. 1 Oktober 2005: 1 – 10
© Kimia ITS – HKI Jatim 9
Chai, Lee Soon and Hamdan, H., 2004, Proc. of
the 2nd Annual Fundamental Science
Seminar AFSS 2004, ISBN-983-9805-54-
1, 2005, 138-140.
Frost and Sullivan, 2001. Zeolites Industry
Trends and Worldwide Markets in 2010.
Technical Insights, New York.Hamdan, H. 2003. Design and Molecular
Engineering fo Nanostructured Zeolites
and Mesomorphous Materials –
Professorial Inaugural Lecture, UTM, Siri 7,
Penerbit UTM.
Hamdan, H., Navijanti, V., Nur, H., and Mohd
Nazlan Mohd Muhid, J. of Solid State
Sciences, 2005 Vol 7, Issue 2, 239-244.
Halimaton Hamdan, Vivin Navijanti, Hadi Nur,
and Mohd Nazlan Mohd Muhid and, J. of
Solid State Sciences, 2005 Vol 7, Issue
2, 239-244. Nur, . Amir Faizal Naidu Abdul Manan, Lim Kheng
Wei, Mohd Nazlan Mohd Muhid and
Halimaton Hamdan, J. of Hazardous
Materials, 117,2005, 35-40.