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.