Optimizing Electron Densities of Ni‐N‐C Complexes by Hybrid Coordination for Efficient Electrocatalytic CO2 Reduction

Abstract Metal‐N‐C is a type of attractive electrocatalyst for efficient CO 2 reduction to CO. Because of the ambiguity in their atomic structures, the active sites and catalytic mechanisms of the catalysts have remained under debate. Here, the effects of N and C hybrid coordination on the activity of Ni‐N‐C catalysts were investigated, combining theoretical and experimental methods. The theoretical calculations revealed that N and C hybrid coordination greatly enhanced the capability of single‐atom Ni active sites to provide electrons to reactant molecules and strengthens the bonding of Ni to N and C in the Ni‐N‐C complexes. During the reaction process, the C and N coordination synergistically optimized the reaction energies in the conversion of CO 2 to CO. A good agreement between theoretical calculations and electrochemical experiments was achieved based on the newly developed Ni‐N‐C electrocatalysts. The activity of hybrid‐coordination NiN 2 C 2 was more than double that of single‐coordination NiN 4 .