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