Synergized Cu/Pb Core/Shell Electrocatalyst for High-Efficiency CO2 Reduction to C2+ Liquids.

The design of efficient copper-based (Cu-based) carbon dioxide reduction (CO2RR) electrocatalysts is crucial for converting CO2 to value-added liquid products. In this work, we demonstrate that the strong synergy between Cu core and ultrathin lead (Pb) shell (0.7 nm) in the Cu/Pb core/shell nanocrystals (NCs, CuPb-0.7/C) significantly boosts the electrocatalytic reduction of CO2 toward C2+ products (products with at least two carbon atoms). Specifically, when applying in a flow cell system, the Faradaic efficiency (FE) of total C2+ products and the selectivity of C2+ liquid products are as high as 81.6% and 49.5%, respectively. Moreover, the current density of C2+ liquid products reaches 196.8 mA cm-2, outperforming most of the reported Cu-based catalysts for CO2RR toward the production of C2+ liquid products. Density functional theory calculations indicate that the synergized Cu/Pb core/shell NCs reduce the formation energies of *COOH and *OCCOH intermediates, as the two critical intermediates for the reduction of CO2 to CO and the formation of C2+ products, respectively, and leads to the significant increase in the selectivity of C2+ liquid products. This study provides a efficient Cu-based catalyst for the reduction of CO2, highlighting the importance of synergistic effect for the design of electrocatalysts in catalysis.