Bimetallic Cu–Zn Catalysts for Electrochemical CO 2 Reduction: Phase-Separated versus Core–Shell Distribution

Electrochemical CO 2 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 CO 2 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 CO 2 reduction performance in detail. Interestingly, the phase-separated sample exhibited much higher activity and stability than the core–shell sample for reducing CO 2 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 CO 2 reduction by tuning the element spatial distribution.