Adjusting Cu-Zn interactions for nitrogen-doped carbon-embedded bimetallic alloys catalyst for selective CO2-to-C2+ electroreduction

The development of bimetallic catalysts offers a promising alternative to monometallic systems for enhancing the selectivity and efficiency of the electrochemical CO 2 reduction reaction (CO 2 RR). However, the fundamental understanding of the synergistic interactions between constituent metals and their role in governing CO 2 RR performance remains insufficient. In this study, we employed a bimetallic Cu/Zn catalyst supported on two-dimensional nitrogen-doped carbon nanosheets (Cu/Zn@CN) to systematically investigate the correlation between structural characteristics, electronic properties, and electrocatalytic performance in CO 2 reduction. Through systematic variation of Zn incorporation, the integration of Cu and Zn within the nitrogen-doped carbon architecture was found to effectively modulate the electronic structure and metal-support interactions, which subsequently governs the binding behavior of key reaction intermediates and enhances both activity and selectivity toward value-added products. The resulting synergistic effects substantially boosted the Faradaic efficiency (FE) and production rate of ethylene and other C 2+ products. The catalyst with a Cu:Zn ratio of 6:2 (Cu 6 Zn 2 @CN) exhibited outstanding performance, achieving a C 2 H 4 FE of 51.16 % with effective suppression of the hydrogen evolution reaction. Combined experimental and density functional theory (DFT) studies revealed that Zn doping modulates the d -band center of Cu, optimizes the adsorption energy of key intermediates such as *OCCO, and reduces the energy barrier of the rate-determining C-C coupling step. The complementary electronic structure and intermediate stabilization effects synergistically contribute to the high C 2+ selectivity. This work provides deep mechanistic insights into the bimetallic cooperation in Cu-Zn electrocatalysts and offers a rational strategy for designing efficient CO 2 -to-C 2+ conversion systems.