ADSORPTION OF WATER ON ZSM-5 ZEOLITES

The non-isothermal desorption of water adsorbed on ZSM-5 zeolites at r oom temperature shows, depending on the cation type (H+, Na+), differe ntly structured desorption curves. A kinetic analysis based on various methods shows that the course of desorption is well described by a fi rst order rate equation considering a distribution function for the de sorption energy. In addition, adsorption isotherms were measured at ro om temperature. The adsorption energy distribution functions calculate d with a regularization method can be correlated with the desorption e nergy distributions, FTIR investigations of water-loaded zeolites enab les the assignment of desorption steps to different adsorbate complexe s.