Molecular Simulations of Hydrogen Storage on Several Nanoporous Zeolites

Abstract

Zeolites belong to a most prominent class of nanoporous materials which have been considered as potential sorbents for hydrogen storage. The adsorption of hydrogen molecules on MFI, MOR and LTA zeolites, which encompass a range of different pore structure and chemical composition, has been simulated employing Grand Canonical Monte Carlo (GCMC) method. We compare their capacities of hydrogen storage at different temperatures and pressures. The results show that the adsorbed amounts is in order of LTA>MOR>MFI at the same condition. The effects of pore structure of zeolites, temperature and pressure on the hydrogen adsorption has been examined. The results clearly show that: (1) the temperature effect on the adsorption decreases with decreasing in the number of hydrogen molecules adsorbed. (2) A large volume of micropores and a suitable diameter near to the kinetic diameter of a hydrogen molecule are important for improving the hydrogen-storage capacity of zeolites. Based on this, we can conclude that the LTA zeolite with a large pore volume and a suitable channel diameter exhibits a most efficient hydrogen storage capacity than MOR and MFI zeolites.