Leveraging Atomic-Scale Synergy for Selective CO2 Electrocatalysis to CO over CuNi Dual-Atom Catalysts

Revealing the synergistic catalytic mechanism involving multiple active centers is crucial for understanding multiphase catalysis. However, the complex structures of catalysts and interfacial environments pose a challenge in thoroughly exploring the experimental evidence. This study reports the utilization of a CuNi dual-atom catalyst (Cu/Ni–NC) for the electrochemical reduction of CO₂. It demonstrates a high Faradaic efficiency of CO exceeding 99%, remarkable reaction activity with a partial current density surpassing –300 mA cm^–2, and prolonged stability for more than 5 days at a current density of –200 mA·cm^–2. Operando characterization techniques and density functional theory calculations reveal that Ni atoms function as active sites for the activation and hydrogenation of CO₂, while Cu atoms serve as active sites for the dissociation of H₂O, supplying protons for the subsequent hydrogenation process. Moreover, the electronic interactions between Ni and Cu atoms facilitate the formation of *COOH and the dissociation of H₂O, illustrating a synergistic reduction of CO₂ at the dual-atom sites.