Enhanced CO2 electroreduction to C2+ production on asymmetric Zn-O-Cu sites via tuning of CO intermediate adsorption

The electrochemical CO2 reduction reaction conducted presents a promising strategy to facilitate the artificial carbon cycle. Unfortunately, the efficiency of eCO2RR-to-C2+ remains below the level required for large-scale implementation due to complex multi-electron transfer and sluggish carbon-carbon coupling. Herein, we constructed asymmetric Zn-O-Cu sites on 2.12 %Zn/CuOx, which achieving a maximum C2+ product FE of 78.77 ± 1.90 % and a high current density of 408.3 mA cm−2. Experimental and theoretical studies reveal that the O-bridged asymmetric Zn-O-Cu sites exhibit enhanced electron transfer, which plays a pivotal role in improving the coverage of *CO and adjusting the adsorption strength of the *CO. The optimal adsorption capacity of the *CO on 2.12 %Zn/CuOx facilitated the subsequent hydrogenation reaction to enhance the conversion of *CO to *COH. Consequently, the asymmetric Zn-O-Cu sites proved to be more thermodynamically favorable for the asymmetric coupling between *CO and *COH, which is conducive to the production of C2+ products. [Display omitted] •We constructed asymmetric Zn-O-Cu sites on the 2.12 %Zn/CuOx.•The 2.12 %Zn/CuOx achieved a maximum C2+ product FE of 78.77 ± 1.90 %.•The Zn-O-Cu sites can adjust the adsorption strength of *CO intermediate.•The asymmetric sites were more favorable for the coupling of *CO and *COH.