Trace-Level Cobalt Dopants Enhance CO2 Electroreduction and Ethylene Formation on Copper

Abstract

The development of Cu-based catalysts for electrochemicalCO<INF>2</INF> reduction reaction (CO<INF>2</INF>RR) with strongerCO-bindingelements had been unsuccessful in improving multicarbon productionfrom the CO<INF>2</INF>RR due to CO-poisoning. Here, we discover thattrace doping levels of Co atoms in Cu, termed CoCu single-atom alloy(SAA), achieve up to twice the formation rate of CO as compared tobare Cu and further demonstrate a high j <INF>C<INF>2</INF>H<INF>4</INF> </INF> of 282 mA cm<SUP>-2</SUP> at -1.01V<INF>RHE</INF> in a neutral electrolyte. From DFT calculations, Cusites neighboring CO-poisoned Co atomic sites accelerate CO<INF>2</INF>-to-CO conversion and enhance the coverage of *CO intermediates requiredfor the formation of multicarbon products. Furthermore, CoCu SAA alsoexhibits active sites that favor the deoxygenation of *HOCCH, whichincreases the selectivity toward ethylene over ethanol. Ultimately,CoCu SAA can simultaneously boost the formation of *CO intermediatesand modulate the selectivity toward ethylene, resulting in one ofthe highest ethylene yields of 15.6%.