High-performance bipolar membrane for CO2 electro-reduction to CO in organic electrolyte with NaOH and Cl2 produced as byproducts

Abstract

Bipolar membranes (BPM) are a special class of ion-exchange membranes constituted by a cation- and an anion-exchange layer, allowing the generation of protons and hydroxide ions via water dissociation. This unique feature makes them useful in a wide range of application. In this work, we have fabricated a novel BPM, with SnO2 hollow spheres used as water dissociation catalyst. Such fabricated BPM has been served as a diaphragm to construct a three-chamber electrolyzer for CO2 electro-reduction to CO in organic electrolyte. During the long-term electrolysis process, the cathodic current density has reached to ∼96.5 mA cm−2, with the Faraday efficiency of CO stabled at ∼92.6 %. Compared with widely used commercial BPM, as-prepared BPM exhibited many advantages, such as lower hydrolysis over-potential, high catalytic efficiency and low total resistance. This technology extends the prospect of BPM application in the field of CO2 reduction.