My research interests lie in engineering catalytic active sites and environments to create active, selective, and stable materials that can help meet the needs for sustainable energy and chemicals. To develop rational design criteria for a given reaction, we must understand the reaction mechanism for desired and undesired pathways and identify how seemingly innocuous changes to the catalytic active site or reaction environment affects rates and selectivities. We will integrate a combination of precise synthetic techniques (e.g., for zeolites, zeotypes, metallic nanoparticles), rigorous intrinsic kinetic measurements, modern in situ and in operando spectroscopic techniques (e.g., Raman, IR, XAS), and thoughtful thermodynamic measurements to understand how complex interactions at the catalytic interface can be engineered to optimize (or enable) desired chemical reactions.
Epoxides are important commodity chemicals and precursors for plastics, foams, and pharmaceuticals; yet, those produced at the largest scale (e.g., propylene oxide) currently require harmful oxidants. My Ph.D. research has focused on understanding how early transition metal-substituted silicates activate hydrogen peroxide and react with alkenes for epoxidation reactions.
My research has showed that the complex interactions that occur at the liquid-solid interface can be broken down into discrete energetic contributions. The differences in epoxidation rates and selectivities between unique catalytic systems (e.g., when changing the metal identity, solvent, pore size, pore polarity) arise as excess free energies that describe differences in electron affinities, confinement, or solvent structure. As a result of these individual contributions, small orthogonal changes to a catalytic system can result in an 8-order-of-magnitude increase in epoxidation rates!
Journal of the American Chemical Society 2019, 141, 7302 – 7319.
ACS Catalysis 2019, 9, 10951-10962.
ACS Catalysis 2018, 8, 2995-3010.
Journal of Catalysis 2018, 364, 415-425.
Journal of the American Chemical Society 2017, 139, 6888-6898.
Journal of Catalysis 2017, 348, 75-89.