Synthesis of Fe/Ni Dual-Metal Single Atoms on 2D Porous N-Doped Carbon for High-Performance Oxygen Reduction

The development of efficient oxygen reduction reaction (ORR) catalysts, aimed at displacing precious metal-reliant materials, constitutes a critical and persistent challenge within sustainable energy conversion technologies. In this study, a bimetallic single-atom (SA) catalyst (SAC) composed of adjacent Fe and Ni SA active sites anchored on two-dimensional (2D) nitrogen-doped carbon nanosheets (FeNi/NC) was constructed via a combination of templating and pyrolysis methods. The catalyst demonstrates outstanding ORR performance, achieving a half-wave potential of 0.92 V, which exceeds those of monometallic SA Fe-N X or Ni-N X counterparts, and commercial Pt/C. Experimental results indicate that the adjacent Fe and Ni SA sites possible function synergistically, leading to an optimized adsorption/desorption of reaction intermediates. The unique 2D nanosheet architecture with open double-sided surfaces provides abundant exposed active surfaces, facilitates efficient mass and charge transport, and improves active site accessibility. This study establishes a viable strategy for fabricating high-performance ORR electrocatalysts, while offering critical perspectives on the rational design of dual-metal single atom catalysts for sustainable energy applications.