Monte Carlo simulations of extraframework cation positions in dehydrated zeolite LiX (Si:Al = 1.25)

Abstract

Abstract A knowledge of extraframework cation positions is crucial for understanding the adsorption and catalytic properties of zeolites. However, diffraction methods are not always able to provide this information with sufficient reliability. Li-containing zeolites (LiLSX, LiX), for example, are particularly difficult to characterize experimentally because of the small X-ray and neutron scattering amplitudes of lithium. The situation is aggravated by the location of Li ions in general positions with low partial occupancies. We show how simulation tools can deal with the partial statistical disorder of the supercage Li cations in zeolite LiX (Si:Al = 1.25) and especially demonstrate the efficacy of canonical ( N, V, T ) Monte Carlo simulations for understanding the cation placements in such systems.