Cascade Dual Sites Modulate Local CO Coverage and Hydrogen-Binding Strength to Boost CO 2 Electroreduction to Ethylene.

Rationally modulating the binding strength of reaction intermediates on surface sites of copper-based catalysts could facilitate C-C coupling to generate multicarbon products in an electrochemical CO 2 reduction reaction. Herein, theoretical calculations reveal that cascade Ag-Cu dual sites could synergistically increase local CO coverage and lower the kinetic barrier for CO protonation, leading to enhanced asymmetric C-C coupling to generate C 2 H 4 . As a proof of concept, the Cu 3 N-Ag nanocubes (NCs) with Ag located in partial Cu sites and a Cu 3 N unit center are successfully synthesized. The Faraday efficiency and partial current density of C 2 H 4 over Cu 3 N-Ag NCs are 7.8 and 9.0 times those of Cu 3 N NCs, respectively. In situ spectroscopies combined with theoretical calculations confirm that Ag sites produce CO and Cu sites promote asymmetric C-C coupling to *COCHO, significantly enhancing the generation of C 2 H 4 . Our work provides new insights into the cascade catalysis strategy at the atomic scale for boosting CO 2 to multicarbon products.