Frequency response and sorption up-take measurements of the molecular mobility of hydrocarbons in ZSM5/silicalites were presented. The diffusivity of ethane at 298K was 6.5 x 10-8cm2/s, with an activation energy of 21.3kJ/mol. The diffusivity of propane at 298K was 3.5 x 10-8cm2/s, with an activation energy of 20.4kJ/mol. Intracrystalline diffusion was established for both n-hexane and benzene in ZSM5/silicalite, but the data obtained for ethane and propane suggested that other processes were also involved.

Molecular Mobility of Hydrocarbon ZSM5/Silicalite Systems Studied by Sorption Uptake and Frequency Response Methods. M.Bülow, H.Schlodder: Studies in Surface Science and Catalysis, 1986, 28, 579–86