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@CuPz(2) comprising of dispersive CuOx and PdO dual nanoclusters embedded in the MOF CuPz(2) (Pz=Pyrazole), which achieves a high C2+ Faradaic efficiency (FEC2+) 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@CuPz(2) compared to Cu@CuPz(2). 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 CuPz(2). 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+.