Trace-Level Cobalt Dopants Enhance CO<sub>2</sub> Electroreduction and Ethylene Formation on Copper
Beomil Kim, Ying Chuan Tan, Yeonkyeong Ryu, Kyuseon Jang, Hafiz Ghulam Abbas, Taehyeok Kang, Hyeonuk Choi, Kug‐Seung Lee, Sojung Park, Wooyul Kim, Pyuck‐Pa Choi, Stefan Ringe, Jihun Oh
Abstract
The development of Cu-based catalysts for electrochemical CO 2 reduction reaction (CO 2 RR) with stronger CO-binding elements had been unsuccessful in improving multicarbon production from the CO 2 RR due to CO-poisoning. Here, we discover that trace doping levels of Co atoms in Cu, termed CoCu single-atom alloy (SAA), achieve up to twice the formation rate of CO as compared to bare Cu and further demonstrate a high j C 2 H 4 of 282 mA cm –2 at −1.01 V RHE in a neutral electrolyte. From DFT calculations, Cu sites neighboring CO-poisoned Co atomic sites accelerate CO 2 -to-CO conversion and enhance the coverage of *CO intermediates required for the formation of multicarbon products. Furthermore, CoCu SAA also exhibits active sites that favor the deoxygenation of *HOCCH, which increases the selectivity toward ethylene over ethanol. Ultimately, CoCu SAA can simultaneously boost the formation of *CO intermediates and modulate the selectivity toward ethylene, resulting in one of the highest ethylene yields of 15.6%.