Kinetic Monte Carlo Modelling to Study Diffusion in Zeolite. Understanding the Impact of Dual Site Isotherm on the Loading Dependence of n-Hexane and n-Heptane Diffusivities in MFI Zeolite, as Revealed by QENS Experiments

ENERGIE:MATERIAUX+HJO:NLA; International audience; This study concerns the diffusion of single-component molecules in zeolites, characterised by an isotherm represented by a dual-site Langmuir model with a point of inflection. The systems investigated are n-hexane and n-heptane in MFI zeolite at 300 K. Experiments conducted using the Quasi-Elastic Neutron Scattering (QENS) technique have demonstrated that this inflection has an impact on the loading dependence of the transport Dt and corrected DC diffusion coefficients of these systems. The results of these experiments are described here. A Kinetic Monte Carlo study is then conducted, showing how the energy levels of the molecule adsorption sites in a zeolite affect the loading dependence of the diffusion coefficients of these molecules.