Electrochemical CO2 reduction to C2+ products over Cu/Zn intermetallic catalysts synthesized by electrodeposition

Abstract

Electrocatalytic CO₂ reduction (ECR) offers an attractive approach to realizing carbon neutrality and producing valuable chemicals and fuels using CO₂ as the feedstock. However, the lack of cost-effective electrocatalysts with better performances has seriously hindered its application. Herein, a one-step co-electrodeposition method was used to introduce Zn, a metal with weak *CO binding energy, into Cu to form Cu/Zn intermetallic catalysts (Cu/Zn IMCs). It was shown that, using an H-cell, the high Faradaic efficiency of C₂₊ hydrocarbons/alcohols \(({\rm{F}}{{\rm{E}}_{{{\rm{C}}_{2 + }}}})\) could be achieved in ECR by adjusting the surface metal components and the applied potential. In suitable conditions, FE_C2+ and current density could be as high as 75% and 40 mA/cm², respectively. Compared with the Cu catalyst, the Cu/Zn IMCs have a lower interfacial charge transfer resistance and a larger electrochemically active surface area (ECSA), which accelerate the reaction. Moreover, the *CO formed on Zn sites can move to Cu sites due to its weak binding with *CO, and thus enhance the C–C coupling on the Cu surface to form C₂₊ products.