Zeolite containing catalytic membranes as interphase contactors

In this study, a catalytic membrane reactor was developed. A titanium silicalite (TS-1) containing polydimethylsiloxane (PDMS) catalytic composite membrane was placed at the interface between the two immiscible phases containing respectively n-hexane (organic phase) and a solution of hydrogen peroxide (aqueous phase). This allowed adequate transport of both reactants to the catalyst surface, without using a co-solvent. This concept of zeolite containing catalytic membrane as interphase contactor, which may be applicable to numerous multiphase reactions, has been tested for the oxyfunctionalization of n-hexane to a mixture of hexanols and hexanones using H2O2 as the oxidant. It was shown that the oxyfunctionalization products are formed in and separated by the catalytic membrane. The experimental results illustrated the technical advantages of such a catalytic membrane reactor since the observed conversion and selectivity are similar to the ones obtained with the same catalyst in a conventional reactor. The various factors (membrane thickness, catalyst loading and membrane modifications) which may affect the membrane catalytic and permeation performances were investigated.