Preparation and characterization of two-layered mordenite-ZSM-5 bi-functional membranes

Two-layered H-ZSM-5-mordenite membranes have been prepared on alumina tubular supports. The objective of this work is to merge the catalytic activity of H-ZSM-5 with the pervaporation water selectivity of mordenite membranes, i.e. to produce true bi-functional zeolite membranes. To be sure that the needed thermal treatment (to remove TPAOH template from the H-ZSM-5 pores) stage did not alter the hydrophilic character of these two-layered H-ZSM-5-mordenite membranes, the calcination was carried out under a steam/air atmosphere. Experiments concerning the pervaporation of water/ethanol mixtures and the esterification of acetic acid with ethanol were performed to demonstrate the applicability of the membranes prepared here.