Sensitivity of Adsorption Isotherms to Minor Differences In Zeolite Structures: A Computational Investigation

Experimental measurements of adsorption isotherms onto zeolites often yield data with considerable variance.  The differences are more dramatic for certain guest-host systems, with a typical example being water sorption in silicalite-1. In molecular simulations, the same kind of sensitivity of adsorption to the zeolite structure, which one takes as simulation input, has also been reported. To further investigate this sensitivity, we have conducted Gibbs ensemble Monte Carlo simulations to calculate the adsorption isotherms for several probe molecules and various zeolite framework types. The extent of the sensitivity of adsorption isotherms to zeolite structures has been determined for each system, and an analysis of the energetics and siting can provide a molecular-level explanation.