Ni Single Atoms/Fe3N Nanoparticles Supported by N‐Doped Carbon Hollow Nanododecahedras with Nanotubes on the Surface for Efficient Electro‐Reduction of CO2 to CO

Abstract The transition metal single atoms (SAs)‐based catalysts with M‐N X coordination environment have shown excellent performance in electrocatalytic reduction of CO 2 , and they have received extensive attention in recent years. However, the presence of SAs makes it very difficult to efficiently improve the coordination environment. In this paper, a method of direct high‐temperature pyrolysis carbonization of ZIF‐8 adsorbed with Ni 2+ and Fe 2+ ions is reported for the synthesis of Ni SAs and Fe 3 N nanoparticles (NPs) supported by the N‐doped carbon (NC) hollow nanododecahedras (HNDs) with nanotubes (NTs) on the surface (Ni SAs/Fe 3 N NPs@NC‐HNDs‐NTs). The synergistic effect between Ni SAs and Fe 3 N NPs can obviously improve the proton‐coupled electron transfer step of CO 2 reduction reaction and promotes the process of electrocatalytic reduction of CO 2 to CO. The fabricated Ni SAs/Fe 3 N NPs@NC‐HNDs‐NTs exhibits a high CO selectivity of up to 94% in the potential range of −0.41–−0.81 V versus Reversible Hydrogen Electrode (vs RHE), and an optimal CO Faraday efficiency (FE CO ) of ≈97.31% at −0.68 V (vs RHE) in the reduction reaction CO 2 to CO. In the theoretical calculation results, due to the non‐bonding synergy effect between Ni SAs and Fe 3 N NPs, the free energy of * COOH formation is greatly reduced and the adsorption of * CO is obviously improved, which will efficiently promote the conversion between the intermediates in the reaction step and accelerate electro‐reduction process of CO 2 . This work will provide a new method for constructing a mutually optimized coordination environment between Ni SAs and Fe 3 N NPs to improve the catalytic performance of CO 2 RR by synergistic complementarity between the dual active sites.