Direct electrochemical CO2 conversion using oxygen-mixed gas on a Cu network cathode and tailored anode

Abstract

Electrochemical CO₂ reduction (eCO₂R) by direct introduction of 60% air-containing CO₂ mixed gas was demonstrated using a porous Cu network cathode formed on a hydrophobic gas diffusion layer (Cu/P-GDL). Cu/P-GDL exhibited eCO₂R using the mixed gas with a remarkable faradaic efficiency of 85% for the production of C₂₊ chemicals, whereas a Cu cathode constructed on a conventional carbon gas diffusion layer (Cu/C-GDL) produced neither eCO₂R products nor H₂. Furthermore, the electrolyzer with Cu/P-GDL and optimized anode configuration achieved a partial current density of 132 mA cm⁻² for C₂₊ chemicals even in the presence of 12% O₂. Demonstration of eCO₂R with impure CO₂ gas would greatly expand its future applications.