Modeling the Kinetic and Transport Effects of Zeolite-Catalyzed Arene Methylation Reactions
Prof. David Hibbitts
Department of Chemical Engineering
University of Florida
ABSTRACT — Zeolites are materials with pores and voids of molecular dimensions and thus are useful materials for sorption, separations, and catalysis. Proton-form zeolites contain Brønsted acid sites capable of catalyzing reactions such as hydrocarbon alkylation, alkene oligomerization, and alcohol dehydration. This seminar will focus on ways in which we have modeled zeolite-catalyzed reactions using density functional theory (DFT) calculations and kinetic Monte Carlo (KMC) simulations in order to interrogate reaction mechanisms as well as the role of acid-site location, pairing, and zeolite crystal size and shape. We will focus on arene methylation and isomerization, which is important for xylene production and is a key part of the methanol-to-olefins process. The large aromatic compounds formed during these reactions can become diffusion limited, giving rise to the trapping of hydrocarbons and catalyst deactivation which are captured through our novel KMC simulations.
Bio: David Hibbitts has been an Assistant Professor in the Department of Chemical Engineering at the University of Florida since August 2015. He received his B.S. degree in Chemical Engineering from Clemson University in 2007 and his Ph.D. degree in Chemical Engineering from the University of Virginia in 2012. His research interests at the University of Florida include 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. His research group involves a combination of experiments and density functional theory studies. David and his group have been awarded three NSF grants in the past year, including the NSF CAREER award; and David was also a recipient of the Provost’s Excellence Award for Assistant Professors at UF (2020).