Sn-modified Cu nanosheets catalyze CO reduction to CH efficiently by stabilizing CO intermediates and promoting CC coupling.

Electrocatalytic CO reduction reaction (CORR) is a process in which CO is reduced to high-value-added C and C energy sources, particularly ethylene (CH), thereby supporting carbon-neutral recycling with minimal consumption. This makes it a promising technology with significant potential. Nevertheless, the low selectivity for CH remains a significant challenge in practical applications. In this paper, a strategy based on Cu-Sn bimetallic catalysts is proposed to improve the selectivity of electrocatalytic conversion of CO to CH over Cu-based catalysts. The experimental results show that the Faradaic efficiency (FE) of CH can reach up to 48.74 %, and the FE of C product reaches 60 %, at which time the local current density is 11.99 mA/cm. Compared with pure Cu catalyst, the FE and local current density of CH increased by 55.27 % and 35.33 %, respectively. Moreover, the FE of CH remained above 40 % after 8 h over Cu-Sn catalyst. The addition of Sn facilitates the transfer of local electrons from Cu to Sn, stabilizes the *CO intermediate, promotes CC coupling, significantly lowers the reaction energy barrier, and enables highly efficient CORR catalysis for CH production.