Synergetic effects of gold-doped copper nanowires with low Au content for enhanced electrocatalytic CO2 reduction to multicarbon products

As efficient catalysts of electrochemical CO2 reduction reaction (CO2RR) towards multicarbon (C2+) products, Cu-based catalysts have faced the challenges of increasing the reactive activity and selectivity. Herein, we decorated the surface of Cu nanowires (Cu NWs) with a small amount of Au nanoparticles (Au NPs) by the homo-nucleation method. When the Au to Cu mass ratio is as little as 0.7 to 99.3, the gold-doped copper nanowires (Cu-Au NWs) could effectively improve the selectivity and activity of CO2RR to C2+ resultants, with the Faradaic efficiency (FE) from 39.7% (Cu NWs) to 65.3%, and the partial current density from 7.0 (Cu NWs) to 12.1 mA/cm2 under −1.25 V vs. reversible hydrogen electrode (RHE). The enhanced electrocatalytic performance could be attributed to the following three synergetic factors. The addition of Au nanoparticles caused a rougher surface of the catalyst, which allowed for more active sites exposed. Besides, Au sites generated ⋆CO intermediates spilling over into Cu sites with the calculated efficiency of 87.2%, which are necessary for multicarbon production. Meanwhile, the interphase electron transferred from Cu to Au induced the electron-deficient Cu, which favored the adsorption of ⋆CO to further generate multicarbon productions. Our results uncovered the morphology, tandem, and electronic effect between Cu NWs and Au NPs facilitated the activity and selectivity of CO2RR to multicarbons.