Leveraging Atomic-Scale\nSynergy for Selective CO<sub>2</sub> Electrocatalysis to CO over CuNi\nDual-Atom Catalysts

Revealing the synergistic catalytic mechanism involving\nmultiple\nactive centers is crucial for understanding multiphase catalysis.\nHowever, the complex structures of catalysts and interfacial environments\npose a challenge in thoroughly exploring the experimental evidence.\nThis study reports the utilization of a CuNi dual-atom catalyst (Cu/Ni–NC)\nfor the electrochemical reduction of CO<sub>2</sub>. It demonstrates\na high Faradaic efficiency of CO exceeding 99%, remarkable reaction\nactivity with a partial current density surpassing –300 mA\ncm<sup>–2</sup>, and prolonged stability for more than 5 days\nat a current density of –200 mA·cm<sup>–2</sup>. <i>Operando</i> characterization techniques and density\nfunctional theory calculations reveal that Ni atoms function as active\nsites for the activation and hydrogenation of CO<sub>2</sub>, while\nCu atoms serve as active sites for the dissociation of H<sub>2</sub>O, supplying protons for the subsequent hydrogenation process. Moreover,\nthe electronic interactions between Ni and Cu atoms facilitate the\nformation of *COOH and the dissociation of H<sub>2</sub>O, illustrating\na synergistic reduction of CO<sub>2</sub> at the dual-atom sites.