The adsorption and diffusion of CH4 and H2 in porous zeolitic imidazolate framework-8 (ZIF-8) material were studied using the methods of equilibrium molecular dynamics and grand canonical Monte Carlo methods; assuming the same force field. It was shown that, using the force field of framework flexibility, not only could the crystal structure of ZIF-8 at different temperatures and pressures be well reproduced, but it was also possible to calculate accurately the diffusion coefficients of CH4 and H2 in ZIF-8 at various temperatures. Adsorbed CH4 at high temperatures could evade the space constraint at the entrance of framework cages in ZIF-8, resulting in a sharp increase in its diffusion coefficient.

Molecular Simulation of Adsorption and Diffusion of CH4 and H2 in ZIF-8 Material. X.Wu, X.Yang, J.Song, W.Cai: Acta Chimica Sinica, 2012, 70[24], 2518-24