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 Pd₂ DAC was synthesized and used for electrochemical CO₂ reduction reaction (CO₂ RR) for the first time. The as-obtained Pd₂ DAC exhibited superior CO₂ RR catalytic performance with 98.2 % CO faradic efficiency at -0.85 V vs. RHE, far exceeding that of Pd₁ SAC, and coupled with long-term stability. The density functional theory (DFT) calculations revealed that the intrinsic reason for the superior activity of Pd₂ DAC toward CO₂ RR was the electron transfer between Pd atoms at the dimeric Pd sites. Thus, Pd₂ DAC possessed moderate adsorption strength of CO*, which was beneficial for CO production in CO₂ RR.