Adsorption and diffusion of alkanes and their mixtures in silicalite studied with positron emission profiling technique

摘要

The Tracer-Exchange Positron Emission Profiling (TEX-PEP) technique hasrnbeen applied for in-situ measurement of the adsorption and diffusion of hexane andrn2-methylpentane mixtures in large crystallite (150μm) of silicalite-1 at 160℃ underrnsteady-state conditions. It was found that n-hexane adsorption is slightly preferred.rnMobility of n-hexane strongly decreases with increasing fraction of 2-methylpentane,rnand it suddenly drops when the pore occupation with 2-methylpentane is muchrnbigger then with n-hexane. A small decrease in the diffusivity of 2-methylpentane isrnalso observed.