Results of a molecular dynamics simulation of xenon in silicalite at 298K and 4 atoms per unit cell (ΔU/ads = -26.9kJ/mol, D = 1.86 x 10-9m2/s) were in good agreement with the experimental value of -24.5kJ/mol and the diffusion coefficient derived from the NMR pulsed field-gradient method (4.00 x 10-9m2/s). The diffusivity was predicted to be negligible at temperatures around 77K and then increased over the investigated range to D = 3.25 x 10-9m2/s at 450K, yielding an activation energy of 5.5kJ/mol. Increasing the concentration from 4 to 16 atoms per unit cell results in a decreased internal energy of adsorption (-28.1kJ/mol) and a decreased diffusion coefficient (D = 0.37 x 10-9m2/s).

Mobility of Adsorbed Species in Zeolites: a Molecular Dynamics Simulation of Xenon in Silicalite. S.D.Pickett, A.K.Nowak, J.M.Thomas, B.K.Peterson, J.F.P.Swift, A.K.Cheetham, C.J.J.Den Ouden, B.Smit, M.F.M.Post: Journal of Physical Chemistry, 1990, 94[4], 1233-6