Highly Selective CO₂Electroreduction to CO on Cu-Co Bimetallic Catalysts

Electrochemical CO2 reduction is of great importance for both decreasing greenhouse gas concentration and producing value-added chemicals and fuels. CO is the key industrial feedstock for the synthesis of various hydrocarbons and alcohols. Herein, we described a facile and effective route to synthesize well-dispersed Cu-Co bimetallic nanoparticles on porous carbon as electrocatalysts for the electroreduction of CO2 to CO. It was demonstrated that the Faradaic efficiency of CO could reach 97.4% with a current density of 62.1 mA cm-2, when MeCN containing 0.5 M ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate was used as the electrolyte. We can find that the current density is significantly higher than other Cu-based catalysts for CO production in the literature. The synergistic effect between Cu and Co in IL-based electrolyte is the main reason for the excellent catalytic performance. The incorporation of Co into Cu leads to higher electrochemical surface area, more space for mass diffusion, strong CO2 adsorption, and appropriate CO2•- adsorption.