Alkaline electrolysis using CuOx cathode for the conversion of carbon dioxide into liquid fuels

Abstract

Electrochemical reduction of CO2 is an effective method for storing intermittent renewable energy. This could result in fuel additives and chemical feedstocks such as alcohols. A challenge of electrochemical alcohol production is the transfer of electrons and protons, as well as the formation of C–C bonds. As of now, copper-based materials are the most commonly used and effective catalysts. Although CuOx is considered a promising catalyst for electrochemical CO2 reduction reactions (CO2RR), significant improvements in product selectivity are still needed. This paper presents some results obtained using copper oxide as a cathode, combined with 33% of ionomer, nickel iron as anode, and membrane Fumatech as electrolyte. As a result of physico-chemical experiments, morphological measurements of the cathode, electrochemical experiments carried out with a complete zero-gap cell operating under alkaline conditions, and gas-chromatographic (GC) analyses of the cathode outlet stream, we determined that methyl formate, ethanol, and propanol were mainly obtained at a rate of 116.3 μmol gcat-1h-1 during operation at 2.2 V.