Tailoring the Coordination of Ni Single Atoms with Synergistic S and P Heteroatoms for Highly Efficient CO2 Electroreduction

The electrocatalytic CO 2 reduction reaction (ECR) represents a promising strategy for converting CO 2 into value-added chemicals while mitigating greenhouse gas emissions. However, developing efficient and stable electrocatalysts remains challenging. In this study, we synthesized a Ni-based single-atom catalyst (Ni/NSP-C) via pyrolysis of a PZS/Ni-ZIF-8 precursor derived from ZIF-8. The resulting catalyst exhibits a hollow polyhedral structure with high surface area and porosity. Crucially, heteroatoms S and P were successfully incorporated into the primary coordination shell of Ni active sites, forming Ni-S and Ni-P bonds that modulate the electronic structure. Electrochemical tests revealed that Ni/NSP-C exhibits efficient ECR performance: a high current density of 402.3 mA cm -2 at -1.5 V vs. RHE, and CO Faradaic efficiency above 94 % over a wide potential window (-0.4 to -1.2 V), reaching 99.61 % at -0.8 V. The catalyst also demonstrated excellent stability over 24 h. Density functional theory (DFT) calculations further revealed that the S and P co-doping lowers the energy barrier for *COOH formation and suppresses the hydrogen evolution reaction, thereby enhancing ECR selectivity and efficiency. This work provides a universal coordination engineering strategy for optimizing the performance of single-atom catalysts in various electrocatalytic applications.