Highly Active and Stable Cu-Cd Bimetallic Oxides for Enhanced Electrochemical CO 2 Reduction

Electrochemical reduction of carbon dioxide (CO ) can produce value-added chemicals such as carbon monoxide (CO) and multicarbon (C ). However, the complex reaction pathways of CO electro-reduction reaction (CO RR) greatly limit the product selectivity and conversion efficiency. Herein, the Cu-Cd bimetallic oxides catalyst was designed and applied for the CO RR. The optimized 4.73 %Cd-CuO exhibits remarkable electrocatalytic CO RR activity for selective CO production in H-cell using 0.5 M 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF )/MeCN as electrolyte. The Faradaic efficiency of CO (FE(CO)) can be maintained above 90 % over a wide potential range of -2.0 to -2.4 V vs. Ag/Ag . Particularly, the catalyst achieves an impressive FE(CO) of 96.3 % with a current density of 60.7 mA cm at -2.2 V vs. Ag/Ag . Furthermore, scaling up the 4.73 %Cd-CuO catalyst into a flow cell can reach 56.64 % FE of C products (ethylene, ethanol and n-propanol) with a current density as high as 600 mA cm steadily. The excellent CO RR performance of the as-synthesized 4.73 %Cd-CuO can be mainly attributed to the introduction of CdO to improve the ability of CuO to activate CO , the electronic interactions between Cu and Cd can boost the activation and conversion the key intermediates of CO RR and ensure the continuous stability of the 4.73 %Cd-CuO in electrolysis process.