Sorption Kinetics of Xenon on MFI‐Type Zeolite Molecular Sieves

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Abstract
Kinetic uptake data for xenon adsorbed onto large and uniform silicalite‐I crystals are presented over a temperature range of 121 K to 296 K. — Adsorption isotherms and corrected diffusion coefficients derived from the uptake curves are given. The heat of adsorption and activation energy of diffusion were estimated from the plots of reciprocal temperature against the logarithm of equilibrium pressure and corrected diffusion coefficients, respectively. — While the corrected diffusion coefficient is independent of coverage for the higher temperatures, it decreases significantly at the lower temperatures investigated (<170 K) when the limiting adsorption capacity has been reached. — Comparing the sorption diffusion data with self‐diffusion coefficients obtained by NMR‐pulsed field gradient techniques, the room‐temperature mobility of xenon in silicalite‐I derived from sorption measurements is lowered by one order of magnitude. However, this result should not be considered necessarily as a discrepancy, due to uncertainties inherent in both techniques.