Highly Active and Stable Cu-Cd Bimetallic Oxides for Enhanced Electrochemical CO2 Reduction

Electrochemical reduction of carbon dioxide (CO2) can produce value-added chemicals such as carbon monoxide (CO) and multicarbon (C2+). However, the complex reaction pathways of CO2 electro-reduction reaction (CO2RR) greatly limit the product selectivity and conversion efficiency. Herein, the Cu-Cd bimetallic oxides catalyst was designed and applied for the CO2RR. The optimized 4.73 %Cd-CuO exhibits remarkable electrocatalytic CO2RR activity for selective CO production in H-cell using 0.5 M 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6)/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-2 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 C2+ products (ethylene, ethanol and n-propanol) with a current density as high as 600 mA cm-2 steadily. The excellent CO2RR 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 CO2, the electronic interactions between Cu and Cd can boost the activation and conversion the key intermediates of CO2RR and ensure the continuous stability of the 4.73 %Cd-CuO in electrolysis process.Electrochemical reduction of carbon dioxide (CO2) can produce value-added chemicals such as carbon monoxide (CO) and multicarbon (C2+). However, the complex reaction pathways of CO2 electro-reduction reaction (CO2RR) greatly limit the product selectivity and conversion efficiency. Herein, the Cu-Cd bimetallic oxides catalyst was designed and applied for the CO2RR. The optimized 4.73 %Cd-CuO exhibits remarkable electrocatalytic CO2RR activity for selective CO production in H-cell using 0.5 M 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6)/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-2 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 C2+ products (ethylene, ethanol and n-propanol) with a current density as high as 600 mA cm-2 steadily. The excellent CO2RR performance of the as-synthesized 4.73 %Cd-CuO can be mainly attr