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 CuO_x 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 \({\text{g}}_{\text{cat}}^{-1} \, {\text{h}}^{-{1}}\) during operation at 2.2 V.