The methods of grand canonical Monte Carlo simulation and molecular dynamics were used to investigate the adsorption and diffusion of benzene in ITQ-1 zeolite. The adsorption energies and preferred adsorption sites of benzene in ITQ-1 were first determined by using grand canonical Monte Carlo simulation. The obtained mass clouds showed that the diffusion and the mobility of benzene occurred mainly in 12-MR super-cages where the preferred adsorption sites of benzene could be divided into three separate adsorption sites. Molecular dynamics simulations were then used to analyze the dynamic diffusion processes. The calculated diffusion coefficients were compared with the results of Sastre et al. (1999). From the trajectories followed by the benzene molecules, it could be seen that the guest molecules did not diffuse in both channel systems, and that only intra-cage mobility was seen in the super-cage voids. The two benzene molecules near to the S2 and S3 sites preferred to adopt a synergistic state, indicating that the benzene molecules at the latter sites could produce relatively strong aromatic stacking interactions.

Adsorption and Diffusion of Benzene in ITQ-1 Type Zeolite: Grand Canonical Monte Carlo and Molecular Dynamics Simulation Study. T.J.Hou, L.L.Zhu, X.J.Xu: Journal of Physical Chemistry B, 2000, 104[39], 9356-64