Modulating the Coordination Structure of Dual‐Atom Nickel Sites for Enlarging CO₂ Electroreduction Potential Window

Abstract

Abstract CO 2 electroreduction (CO 2 ER) is a promising way to change CO 2 into useful CO. However, high CO selectivity can only be realized in a narrow potential range, which largely limits its practical availability. Herein, the potential range for efficient CO 2 ‐to‐CO conversion is effectively enlarged by developing dual‐atom Ni sites with surrounding uncoordinated N dopants dispersed in carbon nanotube substrate. This catalyst is synthesized through a novel precursor gas diffusion strategy to manipulate the coordination structures of atomic Ni. Remarkably, the dual‐atom catalyst exhibits a CO Faradaic efficiency above 92% in an ultra‐wide potential window from a low onset potential of −0.25 to −1.4 V (vs RHE), much superior to those state‐of‐the‐art atomic catalysts. Mechanistically, the unique dual‐atom Ni sites with uncoordinated graphitic N dopants can thermodynamically promote CO 2 ‐to‐CO process via stabilizing the key * COOH intermediate, while simultaneously suppressing the parasitic hydrogen evolution. The findings reveal the correlation between the tailored coordination structures and CO 2 ER performance, so as to further guide the design of atomically dispersed catalysts for CO 2 ER process.