A Supported Pd2 Dual-Atom Site Catalyst for Efficient Electrochemical CO2 Reduction

Dual-atom site catalysts (DACs) have emerged as a new frontier in heterogeneous catalysis because the synergistic effect between adjacent metal atoms can promote their catalytic activity while maintaining the advantages of single-atom site catalysts (SACs), like 100 % atomic utilization efficiency and excellent selectivity. Herein, a supported Pd-2 DAC was synthesized and used for electrochemical CO2 reduction reaction (CO2RR) for the first time. The as-obtained Pd-2 DAC exhibited superior CO2RR catalytic performance with 98.2 % CO faradic efficiency at -0.85 V vs. RHE, far exceeding that of Pd-1 SAC, and coupled with long-term stability. The density functional theory (DFT) calculations revealed that the intrinsic reason for the superior activity of Pd-2 DAC toward CO2RR was the electron transfer between Pd atoms at the dimeric Pd sites. Thus, Pd-2 DAC possessed moderate adsorption strength of CO*, which was beneficial for CO production in CO2RR.