Computational High-Throughput Screening of Transition-Metal C₂N₂ Electrocatalysts for Oxygen Reduction Reactions

With the increasing demand for efficient energy conversion technologies, stable and highly active electrocatalysts have become a key area of research. In recent years, transition-metal (TM) nitrogen-doped carbon-based catalysts have emerged as promising electrocatalysts due to their unique physical and chemical properties. Among the various catalysts aimed at overcoming the efficiency bottlenecks of traditional energy conversion, TM-C₂N₂ has garnered significant attention for its high activity and excellent atomic utilization, demonstrating outstanding performance in the electrochemical oxygen reduction reaction (ORR). However, despite the substantial potential of TM-C₂N₂ in ORR, the impact of different central atoms on the electronic structure and catalytic performance of C₂N₂ has not been systematically studied or deeply explored. In this study, density functional theory combined with high-throughput screening methods was employed to systematically screen TM-C₂N₂ monolayer catalysts composed of different central atoms and to investigate their interaction patterns and catalytic mechanisms in ORR. The computational results indicate that altering the d-band center can effectively reduce excessive adsorption of intermediates, and that the interaction strength between intermediates and TM-C₂N₂ is a key factor determining ORR catalytic activity. Among the 38 candidate materials, we identified two promising candidates, Ti-C₂N₂ and Mn-C₂N₂, which not only exhibit low overpotentials of 0.34 and 0.41 V, respectively, but also possess high thermodynamic and electrochemical stability. This study introduces a novel nonprecious metal catalyst for ORR and reveals the catalytic mechanism of TM-C₂N₂ materials in ORR, providing valuable theoretical guidance for structural optimization and performance enhancement in future catalyst design.