Electro-synthesis of valuable products by coupling energy-saving anodic alcohol oxidation reaction with cathodic CO₂ reduction reaction

Electrocatalytic carbon dioxide reduction reaction (CO₂RR) offers a promising pathway towards achieving carbon neutrality. However, its efficiency is hindered by the sluggish oxygen evolution reaction (OER) at the anode, which consumes a significant portion of the energy input. Herein, we report an effective strategy to replace OER with energy efficient alcohol oxidation reactions to produce value-added products at both cathode and anode of the electrolyzer. In an integrated cell, CO₂RR is carried out at cathode using tin oxide deposited on porous copper (SnO_x@pCu@CF) as an electrocatalyst while alcohol oxidation reactions (methanol, ethanol, benzyl alcohol) are conducted on porous copper (pCu@CF) anode in alkaline electrolyte. Over 89% selectivity for the cathodic reduction of CO₂ into formate and almost 100% selectivity for anodic oxidation of methanol to formate, ethanol to acetate and benzyl alcohol to benzoate are achieved at high current densities within a wide potential range. The SnO_x@pCu@CF//pCu@CF two-electrode arrangement required 100 mV less potential for the overall methanol-assisted CO₂RR as compared to water oxidation assisted CO₂RR with simultaneous production of valuable formate at both anode and cathode This study underscores the potential of coupling CO₂RR with viable alternative oxidation reactions as a theoretically and technically feasible approach as well as holds significant promise for delivering substantial economic benefits.