Realizing site cooperativity in microporous catalysts

The precise placement of chemical functionality surrounding an active site can generate high degrees of catalytic activity and selectivity.  Biological catalysts often exploit the advantages of such concerted approach to catalyze reactions under mild conditions.  We aim to devise synthetic methodologies to create heterogeneous catalysts with organic and inorganic sites that work cooperatively in the activation of targeted molecular species.  Current projects in this realm include designing and implementing water-tolerant solid Lewis acids for the activation of biomass-derived oxygenates for the production of chemicals and fuel intermediates, and investigating bio-inspired approaches for the use of zeolites in low temperature oxidation processes.

Bio-oil upgrading

Bio-oil obtained from biomass pyrolysis is an attractive method to increase the energy density lignocellulosic material.  Crude bio-oil cannot be utilized as a transportation fuel because its oxygen, water, and acid contents are too high.  Therefore, catalytic upgrading methods are necessary to transform bio-oil into more suitable molecules that can be integrated into the refining process.  The aim of this project is to devise catalytic strategies to upgrade the various families of compounds present in bio-oil while minimizing the number of unit operations.  Our approach centers around the use of advanced catalyst synthesis coupled with rigorous kinetic and mechanistic studies for the elucidation of relevant structure-activity relationships.

Designing next-generation electrocatalysts

Renewable energy technologies such as fuel cells, batteries, and photoelectrochemical cells are critically dependent on the design of inexpensive, electrochemically stable, and highly active electrocatalysts.  However, the most active and stable electrocatalysts rely on the use of precious metals such as Platinum, which is the limits the commercial viability of these technologies.  By coupling quantum chemistry calculations with mechanistic experimental studies, our objective is to reveal new classes of stable and highly active electrocatalysts with reduced precious metal loading.  Our approach will center on obtaining an atomic level understanding of the bond breaking and making events associated with the intrinsic properties of the catalyst. We envision that the body of work resulting for the combined theoretical and experimental studies will provide a robust guide for material selection to replace precious metal nanoparticles.

 

Two-dimensional zeolites

There is growing interest in the use of renewable carbon sources for the production of chemicals, polymers, and fuels. Numerous chemical transformations of biomass into a wide variety of products are currently being explored. Upstream and downstream biomass conversion schemes require the use of catalysts that can selectively activate targeted functional groups and promote desired reaction pathways.  Such catalysts will require new open framework architectures to provide free access to large monomeric and oligomeric biomass-derived molecules.  In this respect, zeolite nanosheets are ideal for providing the necessary open topologies with isolated Brønsted or Lewis acid sites, while also offering a high surface area scaffold to tether organic molecules for the creation of multi-functional hybrid catalysts.  This project is broad in nature and some general objectives include: a) creating amphiphilic structure directing agents capable of templating targeted topologies and b) implementing the zeolite nanosheets in sequential reaction sequences involved in biomass conversion, such as hydrolysis/dehydration, isomerization/dehydration, dehydration/C-C coupling.