V activated electro-epoxidation catalyst in membrane electrode assembly system for the production of propylene oxide

Abstract

Direct electro-epoxidation of propylene (D-EOPO) with a membrane electrode assembly (MEA) system represents a sustainable approach for producing propylene oxide, which can reduce ohmic losses and simplify product separation. To address the challenges of selectivity and activity, we develop an Ag/V catalyst and integrate it into the “liquid-free” MEA reactor for continues D-EOPO. The V in the catalyst facilitates the formation of Ag-O active centers, thereby reducing the generation energy of *O radicals. Meanwhile, V doping also results in a downshift of the d-band center of the Ag sites. Consequently, the formation of the crucial intermediate (*OC3H6) is significantly accelerated through the coupling *O with adsorbed propylene, thereby markedly improving propylene oxide (PO) production. The MEA reactor, integrated with the developed Ag/V catalyst, can maintain a stable production rate of PO at 227 μmol/h over a period of 78 hours. Thus, the “liquid-free” electro-epoxidation protocol developed here exhibits greater industrial applicability.