Bimetallic Cu–Zn Catalysts for Electrochemical CO2 Reduction: Phase-Separated versus Core–Shell Distribution

Electrochemical CO2 reduction to fuels and chemicals is considered as one of the most important technologies to reach carbon neutrality. Bimetallic Cu–Zn materials have been proved as effective catalysts for electrochemical CO2 reduction. However, their structure–activity relation remains indistinct. Herein, we prepared two types of Cu–Zn bimetallic catalysts with core–shell and phase-separated structure distributions and studied their electrochemical CO2 reduction performance in detail. Interestingly, the phase-separated sample exhibited much higher activity and stability than the core–shell sample for reducing CO2 to CO, with a faradic efficiency up to 94% and stability beyond 15 h. The density functional theory calculation revealed that the phase-separated sample exhibited a lower energy barrier to form the *COOH intermediate and a more thermodynamically stable state than the core–shell sample. Our work paves an alternative way to design highly active and stable catalyst for electrochemical CO2 reduction by tuning the element spatial distribution.