High-Rate CO Electroreduction to C Products over a Copper-Copper Iodide Catalyst.

Electrochemical CO reduction reaction (CO RR) to multicarbon hydrocarbon and oxygenate (C ) products with high energy density and wide availability is of great importance, as it provides a promising way to achieve the renewable energy storage and close the carbon cycle. Herein we design a Cu-CuI composite catalyst with abundant Cu /Cu interfaces by physically mixing Cu nanoparticles and CuI powders. The composite catalyst achieves a remarkable C partial current density of 591 mA cm at -1.0 V vs. reversible hydrogen electrode in a flow cell, substantially higher than Cu (329 mA cm ) and CuI (96 mA cm ) counterparts. Induced by alkaline electrolyte and applied potential, the Cu-CuI composite catalyst undergoes significant reconstruction under CO RR conditions. The high-rate C production over Cu-CuI is ascribed to the presence of residual Cu and adsorbed iodine species which improve CO adsorption and facilitate C-C coupling.