Novel bipolar membrane electrolyzer for CO2 reduction to CO in organic electrolyte with Cl2 and NaOH produced as byproducts

Abstract

Electrochemical reduction of CO2 to valuable products, powered by renewable energy, provides a promising strategy for reducing our dependence on fossil fuels. But up to now, no technology has been implemented for large-scale industrial applications. Without massive utilization of CO2, many vital practical problems, such as reducing CO2 emissions, storing renewable energy, and alleviating environmental pollution, cannot be resolved through this route. Herein, we propose a novel electrolyzer for CO2 electro-reduction, which is separated into three chambers by a bipolar membrane and a cation exchange membrane. In the cathodic chamber, CO2 is reduced to CO in organic electrolytes. In the anodic chamber, Cl- is oxidized to Cl2 in NaCl aqueous solution. In the central chamber, NaOH is obtained. The generated CO and Cl2 can be used as feedstock to produce phosgene (CO+Cl2 =COCl2). Through this route, phosgene can be produced from CO2 and NaCl, with NaOH generated as a byproduct. By substantially increasing the product value, we can promote CO2 electro-reduction technology to industrial applications.