MOLECULAR-DYNAMICS STUDIES ON ZEOLITES .6. TEMPERATURE-DEPENDENCE OF DIFFUSION OF METHANE IN SILICALITE

The effect of the temperature on the diffusion of methane in silicalite was studied by molecular dynamics both using a model where the vibrations of the zeolite framework are taken into account and keeping the framework fixed. Methane molecules were represented by Lennard-Jones particles. The diffusion coefficients were evaluated at four different temperatures in the range 150-450 K and resulted in good agreement with experiment. The effect of the vibrating framework on the diffusive process is discussed and a detailed analysis of the behavior of methane molecules in silicalite is reported.