Zeolites are a group of porous, crystalline, aluminosilicate minerals with widespread applications in catalysis, medicine, and as sorbents. Adsorption behavior, particularly for applications in CO<sub>2</sub> separation and carbon capture, depends heavily on the motion of extra-framework cations. We used <i>ab-initio</i> molecular dynamics (AIMD) simulations to study the thermal fluctuations of the extra-framework cations and framework in zeolites LTA, RHO, MFI, and MOR. LTA and RHO are cage-type zeolites, with large, roughly spherical pore spaces connected by short, narrow passageways, while MOR and MFI are channel-type zeolites, with cylindrical pores running through the entire structure. We characterized the behavior of the extra-framework cations by locating cation sites, which are accessible experimentally only as average positions due to poor time resolution. Through our atomistic simulations, we developed a more nuanced perspective as to how cations fluctuate in and out of the sites over femtosecond timescales. Channel-type zeolites were shown to have more symmetrically non-equivalent sites than cage-type zeolites and showed an overall higher degree of cation mobility.

Computational insight into cation dynamics in zeolites

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.