Ultra-high-rate CO2 reduction reactions to multicarbon products with a current density of 1.7 A cm−2 in neutral electrolytes

Abstract

CO₂ electrolysis to value-added products is a promising technology to close the carbon cycle and sequester anthropogenic CO₂ into chemical feedstocks; an increase of the current density for multicarbon products is one of the requirements for practical implementation. We have successfully increased the partial current density for gaseous CO₂ reduction reactions to multicarbon products (C₂₊) over Cu nanoparticles on gas diffusion electrodes in neutral electrolytes to a record value of 1.7 A cm⁻². The faradaic efficiency for multicarbon products increased with the current density below total current density of 2000 mA cm⁻² and reached 76% at a total current density of 1600 mA cm⁻². The turnover frequency for the production of C₂₊ per Cu atoms exceeded 1.1 s⁻¹. Optimizing the standard components and their assembly as the cathode elicits the high-turnover frequency of oxide-derived Cu catalysts, resulting in the record partial current density for C₂₊. Especially, we demonstrated that the thickness of catalyst layers was one highly sensitive factor in determining the maximum current density for C₂₊.