The Kinetic Monte Carlo Simulations of the Self-Diffusivity in Zeolites

The diffusion of guest molecules in zeolites is investigated in the framework of a one-dimensional lattice-gas model with two non-equivalent sites. The concentration dependencies of the tracer and center-of-mass diffusion coefficients are calculated for some representative values of the lateral interaction between the guest molecules. Using simple ideas about molecules diffusion we propose analytical expressions for the diffusion coefficients. We compare the theoretical dependencies with the numerical data obtained by the kinetic Monte Carlo simulations. A very good coincidence of the data obtained by the two quite independent different methods corroborates strongly the validity of the proposed approach.