Intercrystalline molecular transport in zeolites studied by uptake experiments and by nuclear magnetic resonance pulsed field gradient techniques

Abstract

A comparison of n.m.r. self-diffusion and uptake measurements was performed with the systems cyclohexane (n-hexane)+NaX-zeolite. For intracrystalline adsorption kinetics a significant difference in the values of the corresponding rate constants was found. Intercrystalline self-diffusion coefficients and corresponding uptake coefficients, however, were found to be in good agreement. In accordance with this result, in both n.m.r. and uptake experiments the variation of pressure of compaction, sorbate concentration and temperature led to the same changes in the effective coefficients of intercystalline transport.