Molecular Dynamics Simulation Of The Molecular Anisotropic Diffusion In ITQ-3 Zeolite

In this paper,we have studied the molecular dynamics on ITQ-3 molecular sieve using molecules dynamics simulation, especially,the anisotropic diffusion behavior of spherical molecules methane and argon in the ITQ-3 zeolite. By analyzing the simulation results, set up a transition state and random walk model of molecular in ITQ-3 molecular sieve has been proposed. In this model, on account of the molecules from a adsorption in the cavity cross the barrier to the adjacent another cavity of adsorption must to overcome a big barrier, mutual attraction and relatively small, so the molecules in the barrier can simplify the processing is only exist repulsive potential. In transition state theory based on molecular diffusion model in the ITQ- 3 narrow channel direction, the diffusion coefficient can be obtained with the analytical relationship between temperature and energy parameters. Based on ITQ- 3molecules in molecular sieve of random diffusion model, the molecule is considered to be on the adsorption of a transition and the transition to the adjacent cavity has the same adsorption a chance. The molecules can be obtained along the ITQ- 3 molecular sieve diffusion coefficients of two axis direction and there is a certain relationship.All in all, the anisotropic diffusion of spherical molecular in the pores of ITQ-3 narrow zeolite was investigated by molecule dynamics simulation to verify the transition state model theory and the random diffusion model theory.These provide new ideas and methods to measure the physical, chemical phenomena and process which use the modern experimental methods to study and to explore the physical and chemical mechanism provides a new thought.