Bimetallic Au-Cu gradient alloy for electrochemical CO2 reduction into C2H4 at low overpotential

Electrocatalytic reduction of CO2 (CO2RR) represents a promising approach to reduce CO2 emission and generate value-added chemicals. Herein, we developed bimetallic Au-Cu gradient alloy nanostructures (AuCu-g) comprising of ultrathin Cu-rich alloy surface and Au-rich alloy core as electrocatalyst via a facial solvothermal method. Impressively, the AuCu-g can stably generate a considerable amount of C2H4 with faradaic efficiency (FE) ∼20 % at a low limiting potential of −0.4 V versus reversible hydrogen electrode (RHE) due to its unique gradient structure and multi-component tandem effect. The potential-dependent in situ Raman spectrum indicated an enhanced *CO adsorption strength and a remarkable CO intermediate generation over Au-Cu gradient alloy at low overpotentials during CO2 reduction process. This work shines a light for developing mutilmetallics toward efficient CO2 RR.