Dual-Metal Sites Drive Tandem Electrocatalytic CO₂ to C₂₊ Products

The electrochemical conversion of CO₂ into valuable chemicals is a promising route for renowable energy storage and the mitigation of greenhouse gas emission, and production of multicarbon (C₂₊) products is highly desired. Here, we report a 1.4 %Pd-Cu@CuPz₂ comprising of dispersive CuO_x and PdO dual nanoclusters embedded in the MOF CuPz₂ (Pz=Pyrazole), which achieves a high C₂₊ Faradaic efficiency (FE_C2+) of 81.9 % and C₂₊ alcohol FE of 47.5 % with remarkable stability when using 0.1 M KCl aqueous solution as electrolyte in a typical H-cell. Particularly, the FE of alcohol is obviously improved on 1.4 %Pd-Cu@CuPz₂ compared to Cu@CuPz₂. Theoretical calculations have revealed that the enhanced interfacial electron transfer facilitates the adsorption of *CO intermediate and *CO-*CO dimerization on the Cu-Pd dual sites bridged by Cu nodes of CuPz₂. Additionally, the oxophilicity of Pd can stabilize the key intermediate *CH₂CHO and promote subsequent proton-coupled electron transfer more efficiently, confirming that the formation pathway is skew towards *C₂H₅OH. Consequently, the Cu-Pd dual sites play a synergistic tandem role in cooperatively improving the selectivity of alcohol and accelerating reductive conversion of CO₂ to C₂₊.