Abstract:

Molecular dynamics has been performed to study the diffusion behaviors of benzene molecules in pure siliceous MCM-22 analog: ITQ-1. The diffusion coefficients of benzene do not show obvious differences using rigid zeolite framework or flexible zeolite framework, which means the flexibility of the zeolite framework does not introduce remarkable effects to the simulation results. From the trajectories of molecular dynamics, it can be found that the diffusion and migration of benzene mainly occured in 12-MW cavities, while high activtion energy must be needed when one sorbate molecule migrating from one 12-MW cavity to another nerarby 12-MW cavity through the 10-MW windows. Moreover, the diffusion characteristics of the benzene molecules indicates that a pair of benzene molecules in S1 and S2 sites will produce relatively strong π－π stacking force and the motions between two benzenes near S1 and S2 sites will keep very synergistic status in order to make the system remaining in the state of optimal energy.

Key words: ITQ-1, Molecular dynamics, Diffusion