Dual-Atomic Cu Sites for Electrocatalytic CO Reduction to C₂₊ Products

Monodispersed single metal atoms have been demonstrated with unique potentials for electroreduction of CO2 or CO, while the capability of producing multicarbon (C2+) products is still limited. In this work, we developed a dual metal atomic catalyst with uniform distributions of two adjacent Cu–Cu or Cu–Ni atoms anchored on nitrogen-doped carbon frameworks, featuring distinctive catalytic sites for CO electroreduction. Due to the synergistic effect between adjacent metal sites, the dual Cu–Cu atomic catalyst enables efficient CO electroreduction to C2+ products with an outstanding Faradaic efficiency of ∼91% and a high partial current density over 90 mA·cm–2. In contrast, the dual Cu–Ni atomic catalyst exhibits a remarkably different CO electroreduction selectivity mainly toward CH4. Theoretical calculations suggest that the dual Cu atomic sites facilitate the electroreduction of two CO molecules and subsequent carbon–carbon coupling toward ethylene and acetate, while the replacement of one of the dual Cu atoms with Ni results in too strong CO adsorption, and thus only the single Cu atom functions as the catalytic site for the C1 reduction pathway.