Engineering Active Sites for Sustainable Catalysis
Robert Raja
Cascade Reactions & Flow Chemistry
Vitamins Agrochemicals Fragrances and flavours Food-additives
Porous Molecular Frameworks
The Strategy:
Designing novel framework structures (zeolites, AlPOs, MOFs, ZIFS).
Isomorphous substitution of framework anions and cations with catalytically active transition-metal entities.
Take advantage of pore aperture for shape-, regio- and enantio-selectivity
Properties:
Hybrid/hierarchical architectures. Wide-ranging chemical properties
Redox catalysis (selective oxidations, epoxidation).
Acid catalysis (alkylations, isomerisations, dehydration).
Bifunctional and cascade reactions
Oxyfunctionalization of alkanes and aromatics (C–H activation)
High thermal stability/recyclability
Structure-property relationships
Greener NylonTerephthalate-based fibresLiquid-phase Beckmann reactions-Caprolactam synthesisBio-Ethanol dehydration
Fine-Chemicals & Pharmaceuticals
Industrial Research ProjectsBulk Chemicals & Energy
Key Benefits:
Replace highly corrosive and more expensive oxidants with benign ones (molecular oxygen)
Access mechanistic pathways that were hitherto difficult
Synergy in catalytic transformations
Catalyst and process conditions amenable for industrial exploitation
Chem. Commun., 2011, 47, 517–519
Engineering Active Sites for Enhancing Catalytic Synergy
Role in Future Challenges Sustainable energy Atom-efficient Catalysis Benign Reagents Eliminate Waste Renewable Fuels
Renewable energy
Clean drinking water
CO2 capture
Sustainable Catalysis For Renewable Energy Applications:
Research Areas
Renewable Transport Fuels Bio-Ethanol & Biomass
Conversions Hybrid Biofuels (1st and 2nd
generation) Bio-diesel
Hydrogen EconomyIndustrial HydrogenationsLow-temperature acid catalysisAlternatives to PGM
Catalysts
Key Benefits:
Better compositional control compared to traditional methods such as incipient wetness and deposition/precipitation
Improved site-isolation aids catalytic turnover
Use of oxophile reduces amount of noble metals and aids anchoring
Exceptional synergy in catalytic reactions (akin to enzymes)
Access mechanistic pathways that were hitherto difficult
Process conditions amenable for industrial exploitation
Collaborative Projects
1. Photocatalytic-splitting of water for the generation of H2 and O2
2. Harvesting marine-energy for potential impact on H2 economy
Engineering Perspective
1. Developing marine exhaust-gas cleaning technologies
2. Selective catalytic reduction for removal on NOx, SOx, VOCs, particulates from diesel engines
Dalton Trans., 2012, 41, 982-989
OO O
OH
OHHO
OH
OHOH
On
OHOHO
OH OH
OH
Cellulose Glucose
OHO O
5-Hydroxymethylfurfural
O OH
OH
HO
HO
Fructose
OH
O
O
Methyl lactate
OH
H+
MesoporesSn4+
Micropores
H+
Micropores
Methanol, Sn4+
Micropores
Hierarchical AlPO pore
20-30A
AFI Framework7.3A
AFI Framework7.3A
AFI Framework7.3A
Hybrid Catalysts for Biomass Conversions and Multifunctional Hierarchical Architectures for Biodiesel Production
Bio-Ethanol/ Propanol
Ethylene/Propylene
Synergy
Academic & Industrial Partnership Programs•Renewable Transport Fuels•Bio-Ethanol and Biomass Conversions•Hybrid Biofuels (1st and 2nd Generation)•Biodiesel & Bioenergy•Hydrogen Economy•Alternatives to PGM Catalysts•Industrial Hydrogenations•Low-Temperature Acid-Catalysis•Renewable Polymers
Micropore7.3Å
Mesopore25Å
Micropore7.3Å
Mesopore25Å
Ru3Sn Nanoparticle
cluster
H2C O
HC
H2C
O
O
O
O
O
R1
R2
R3
+ 3CH3-OH
H3C O
H3C
H3C
O
O
O
O
O
R1
R2
R3
H2C OH
HC
H2C
OH
OH
+
Triglyceride
Methanol
H+
Methyl esters(Biodiesel) Glycerol
Ru0
Hydrogenolysis
OHHO
1,3-Propanediol
OHHO
O
Co3+
Oxidation
3-Hydroxypropanoic acid
Hierarchical Framework pore
20-30AHierarchical
Framework pore20-30A
AFI Framework7.3A
Single-Step Cascade Reactions for the Conversion of Vegetable Oils to FAMES
&Direct Glycerol conversion to 1,3-propanediol