Molecular simulation of hydrogen storage in ion-exchanged Mazzite and Levyne zeolites

The ion-exchanged zeolites Mazzite and Levyne with alkali metal cation (Na+), acid proton (H+) and alkaline earth metal cation (Ca2+), have been used to analyze the effect of framework structures, micropore volume, pore sizes and exchangeable cations on hydrogen storage at different temperatures and pressures using the grand canonical Monte Carlo (GCMC) method. The simulation data clearly show that a larger micropore volume and a suitable pore size near to the kinetic diameter of a hydrogen molecule are the main factors affecting the hydrogen storage capacity. In addition, choosing an appropriate exchangeable cation could also produce a strong electric field and encapsulate hydrogen in the small cages, which would be beneficial for hydrogen storage. (C) 2011 Elsevier B.V. All rights reserved.