David Hibbitts, Associate Professor, University of Florida

"Modeling Kinetic and Transport Effects in Zeolite-Catalyzed Xylene-Formation Reactions"

Abstract:

Zeolites are microporous aluminosilicate materials that have applications in separations and catalysis. Their pores solvate reaction intermediates and transition states to drive catalytic reactions and create diffusive restrictions that can limit the rate of mass transport into and out of zeolite crystals. These effects make zeolites "molecular sieves" that confer "shape selectivity" in the reactions they perform. For instance, during reactions of toluene to make xylenes, the selectivity to the isomer which diffuses most readily (para-xylene) is enhanced over its slower-diffusing cousins (ortho- and meta-xylene). In this seminar, I will describe how we model reactions and transport in zeolites and how they depend on the location of acid sites in the framework. Furthermore, I will discuss how reaction and diffusion energy barriers can be used as inputs into kinetic Monte Carlo simulations to model reactions in large zeolite crystals at conditions where both kinetic and transport influence observed properties.

Bio:

Bio:

David Hibbitts is the Moreno Rising Star Associate Professor in the Department of Chemical Engineering at the University of Florida, and will start as an Associate Professor in the Davidson School of Chemical Engineering at Purdue University in January 2025. David started at UF in 2015, after a post-doctoral appointment at the University of California at Berkeley. He received his B.S. in Chemical Engineering from Clemson University in 2007 and his Ph.D. in Chemical Engineering from the University of Virginia in 2012. His research group focuses on the determination of reaction mechanisms and structure-function relationships for the conversion of biomass- and fossil-derived feedstocks into fuels and chemicals through heterogeneous catalysts using a combination of theoretical and experimental approaches. He is the recipient of the ACS PRF New Doctoral Investigator award, the NSF CAREER Award, and a 2020 Excellence award for Assistant Professors at the University of Florida.