Channel-dependent entropy buffering in MFI zeolites: Mitigating thermal resistance in n-Heptane diffusion

Abstract

This study resolves anomalous high-temperature diffusion suppression in MFI zeolites by establishing configurational entropy buffering thresholds that counteract the Thermal Resistance Effect (TRE). Molecular dynamics (MD) simulations demonstrate that intersections function as entropy reservoirs, where exceeding a critical molecular trapping frequency triggers diffusion suppression by overwhelming the buffering capacity. Crucially, sinusoidal channels enable near-complete diffusivity recovery through curvature-assisted conformational accommodation with ultralow energy barriers, while straight channels exhibit irreversible suppression due to geometric constraints. These findings elucidate the critical role of sinusoidal channel geometry in entropy-mediated strain dissipation, providing a fundamental molecular-level insight that could inform the design of zeolite catalysts with improved diffusion properties under thermal stress.