Computer simulated diffusion of C7 hydrocarbons in microporous materials: Molecular modeling

Molecular modeling methods (molecular dynamics and forced diffusion) were used for analyzing the phenomenon of C7 hydrocarbons diffusion in microporous materials. Models of zeolites (ZSM-5 and faujasite), aluminum oxide (support) and aluminum oxide with Pt atoms (catalyst of the dehydrocyclization reaction) were adopted as adsorbents. In both zeolite models an energy barrier was observed during translation of the hydrocarbon molecules through the narrowings of the pores. No such barrier was found to occur in the narrow pore of the aluminum oxide model. The lower diffusion coefficient in this model should be attributed to the stronger adsorption, i.e., to the reduced potentiality for a free motion of molecules.