Multidimensional coordination engineering of single-atom catalysts for boosting electrochemical CO2 reduction

The breaking of the symmetric electronic distribution of single-atom catalysts is effective in improving the intrinsic activity. However, traditional modification strategies can only disrupt the electronic distribution in one dimension, resulting in limited regulation of electronic structure. Herein, we report a multidimensional coordination strategy to significantly break the symmetrical electron distribution of the metal single site to achieve highly efficient electrochemical CO2 reduction reaction (CO2RR). Ni single-atom sites decorated with planar P and axial Cl atoms are successfully constructed on carbon support (Ni-NPCl-C). Ni-NPCl-C affords CO Faraday efficiency over 90% in a wide potential window range from −0.5 to −1.2 V and an ultrahigh turnover frequency of 1.17×105 h−1, much superior to its counterparts with single-dimensional coordination. Ni-NPCl-C can be further applied as a bifunctional catalyst to construct a rechargeable Zn-CO2 battery. Spectroscopic characterizations and theoretical calculations demonstrate that the dual adjustments with axial Cl and planar P can synergistically disrupt the electron distribution in two dimensions to increase electrons around Ni sites with the upshift of the d-band center, thereby facilitating the formation of *COOH intermediates and improving the CO2RR performance.