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

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