High-Performance Pd₂Cu₂ Cluster Supported on CeO₂(110) for the Electroreduction of CO₂

Copper and palladium exhibit excellent catalytic performance for the electrochemical reduction of CO2 (CO2RR). Here, a PdxCu4–x (x = 2, 3) cluster was supported on CeO2 with different sites to form three kinds of novel nanocatalysts, namely, Pd2Cu2/CeO2, Pd3Cu/CeO2 (Pd–Pd), and Pd3Cu/CeO2 (Pd–Cu). Based on density functional theory, the catalytic performance and selective mechanisms were studied systematically. During the process of CO2RR, *CO was hydrogenated to produce deeply reduced products such as CH4 or CH3OH due to its strong adsorption energies on all three catalysts (Pd3Cu/CeO2(Pd–Pd) for 0.95 eV, Pd3Cu/CeO2(Pd–Cu) for 0.89 eV, and Pd2Cu2/CeO2 for 1.22 eV). The overpotential to form the CH4 or CH3OH product can be changed by varying the atomic ratio or anchoring sites of PdxCu4–x clusters on CeO2. In particular, the CO2RR on Pd2Cu2/CeO2 showed the lowest overpotentiontial (−0.60 eV) compared to the other two Pd3Cu/CeO2 catalysts. This study extends the family of CO2RR catalysts and the application scenarios of bimetallic catalysts, which provides new insights into the design and preparation of composite nanocatalysts.