Adsorption of light alkanes on silicalite-1: Reconciliation of experimental data and molecular simulations

Abstract

Adsorption isotherms of methane, ethane, propane, n-butane, and isobutane on silicalite-1 are reported at multiple temperatures. The reconciliation of the experimental data and molecular simulations provides an excellent interpretation of the adsorption in terms of a volume filling process with two different spaces. This can be described by a dual-site Langmuir expression. The derived thermodynamic properties such as adsorption enthalpy and entropy are in good agreement with those determined by other techniques in the literature. The observed two-step adsorption behavior for isobutane on silicalite-1 is attributed to the large difference in the adsorption entropy between the molecular locations in the intersections and in the channels.