Monte Carlo simulations of self- and transport-diffusivities of 2-methylhexane in silicalite

Abstract

We report kinetic Monte Carlo (KMC) simulations of self- and transport-diffusivities of 2-methylhexane (2MH) in silicalite. The hopping rates of 2MH along the straight and zig-zag channels were chosen based on the calculations of Smit (Faraday Discuss., 1997, 106, 93). The self-diffusivity tensor was found to exhibit anisotropy and strongly dependent on the occupancy or loading. The degree of anisotropy of the self-diffusivity tensor decreases with loading, a hitherto unreported result. The loading dependence is shown to be due to correlation effects. Such correlation effects, do not however influence the behavior of the transport-diffusivity which exhibits a predictable Langmuirian dependence on loading.