(707d) Adsorption of Bulky Molecules in Zeolites from Liquid Mixtures: From Model Development to Molecular Dynamics

Lewis acidic zeolites are formed by the isomorphous substitution of framework Al³⁺/Si⁴⁺ atoms with metal cations and serve as single-site catalysts in a wide range of chemical reactions. Confinement in zeolites enables the size- and shape-selective catalysis on active sites, controlling the orientation of guest molecules within the pores and leading to entropic penalties and enthalpic stabilizations (through electrostatics and dispersion) of adsorbates in the “right fit” configuration. These competing thermodynamic effects are well-documented in the literature for lighter olefins. Additionally, they have been found crucial for explaining reactivity trends in epoxidations of long-chain alkenes in Ti-substituted BEA zeolites [1].

Building on our previous simulation efforts [1], we investigate the epoxidation of alkenes catalyzed by BEA zeolites substituted with Group IV and V transition metals as a model reaction, and expand existing computational protocols by introducing a comprehensive workflow that encompasses system construction, force field development, and grand canonical molecular dynamics (GCMD) simulations. With this approach, we aim to provide mechanistic insights into the factors influencing guest molecule adsorption thermodynamics and bridge the gap between multi-scale modeling and experimental observations.

Reference:

[1] Potts, D. S., Jeyaraj, V. S., Kwon, O., Ghosh, R., Mironenko, A. V., & Flaherty, D. W. (2022). Effect of interactions between alkyl chains and solvent structures on Lewis acid catalyzed epoxidations. ACS Catalysis, 12(21), 13372-13393.