Zeolites are the workhorse of today’s chemical industry with a wide array of catalytic applications. These crystalline microporous aluminosilicate materials with a high degree of molecular shape selectivity, tuneable acidity and resistance to harsh reaction conditions are ideally suited for the conversion of complex feedstocks. Nowadays, thanks to their excellent properties and versatility, zeolites are being explored as catalysts for the sustainable production of fuels, aromatics and base chemicals from non-fossil derived feedstocks such as captured CO2, methanol, plastic waste or biomass. A key challenge in this transition to a circular economy consists in the design of zeolite catalysts with optimal activity and selectivity for each targeted application.
Tackling this challenge successfully requires detailed insight into the intricate reaction mechanisms and the nature of the zeolite structures and active sites at operating conditions through a synergistic approach between experiment and theory. Zeolite materials exist in many forms and shapes and can be tailored to target the preferred reaction products and enhance catalyst lifetime. Three promising strategies for improving the catalytic performance are:
(i) Altering the pore size distribution of the zeolite by introducing mesopores and nanopores
(ii) Modifying the zeolite crystal morphology to optimize the external surface/volume ratio
(iii) Tuning the acid site strength and distribution of the zeolite Brønsted and Lewis acid sites
A catalytic process is characterized by a series of events (diffusion, adsorption, reaction, desorption,…) taking place on different length and time scales and which are often correlated. Next to the specific reaction conditions (temperature, pressure, presence of impurities and water,…), each strategy for tailoring the zeolite may have important ramifications on one or multiple events. The main objective of this research line is to obtain an integrated molecular-level view of the dynamic zeolite catalyst particle at realistic conditions upon the conversion of complex hydrocarbon feedstocks. This way, we can obtain the necessary fundamental insight in order to advance the design of next-generation zeolite catalysts for sustainable processes.
Core publications
Operando modeling of zeolite catalyzed reactions using first principle molecular dynamics simulations. V. Van Speybroeck, M. Bocus, P. Cnudde, L. Vanduyfhuys (2023) ACS Catalysis, 13, 17, 11455-11493. doi: 10.1021/acscatal.3c01945
The nature of extraframework aluminum species and Brønsted acid site interactions under catalytic operating conditions. J. L. Mancuso, V. Van Speybroeck (2024) Journal of catalysis, 429, 115211. doi: 10.1016/j.jcat.2023.115211
Nuclear quantum effects on zeolite proton hopping kinetics explored with machine learning potentials and path integral molecular dynamics. M. Bocus, R. Goeminne, A. Lamaire, M. Cools-Ceuppens, T. Verstraelen, V. Van Speybroeck (2023) Nature Communications, 14, 1008. doi: 10.1038/s41467-023-36666-y
Experimental and theoretical evidence for promotional effect of acid sites on the diffusion of alkenes through small-pore zeolites. P. Cnudde, E.A. Redekop, W. Dai, N.G. Porcaro, M. Waroquier, S. Bordiga, M. Hunger, L. Li, U. Olsbye, V. Van Speybroeck (2021) Angewandte Chemie Int. Ed., 60(18), 10016-10022. doi: 10.1002/anie.202017025
