Screening Framework of Metal–N–C Diatomic Catalysts for Electrochemical CO ₂ Reduction

Diatomic catalysts (DACs), owing to their reduced cost, high efficiency, and good stability, have emerged as potential catalysts for electrochemical CO2 reduction (CO2RR). While, further development of CO2RR DACs is hampered by the limited understanding of their dual-atom catalytic center. This study systematically screens nitrogen-doped graphene-based DACs by incorporating 13 metals by means of density functional theory calculations and machine learning. NiMn–N–C and SnNi–N–C have emerged as candidates for the CO2RR, facilitating the production of CO and HCOOH, respectively. The key finding is that NiMn–N–C exhibits catalytic stability over a wide range of pH values and applied potentials, particularly under strongly acidic conditions, compared with other reported DACs. While acidic CO2RR performance is hindered by DAC instability and competing hydrogen evolution, NiMn–N–C emerges as a candidate for efficient acidic CO2RR applications. The findings offer valuable insights into DAC operational principles, contributing to the rational design of highly efficient catalysts for pH-universal electrolyte CO2RR applications.