FeCu Bimetallic Single-Atom Catalyst: Empowering Highly Efficient Oxygen Reduction Kinetics

Abstract Iron and nitrogen co-doped carbon materials (Fe-N-C) have garnered widespread attention owing to their highly active Fe-N4 sites. Here, we proposed a novel approach for synthesizing bimetallic single-atom catalysts by introducing Cu atoms into Fe-N-C. The resultant Fe-Cu-NC catalyst exhibited a large specific surface area. Moreover, it had a superior half-wave potential of 0.890 V (vs. RHE) in alkaline media. Density functional theory calculations disclosed that the introduction of Cu augmented the adsorption capacity of Fe-N4 active sites concerning oxygen intermediates, thus accelerating the reaction pathway and markedly enhancing the catalytic activity of the oxygen reduction reaction (ORR). When employed as the cathode of a zinc-air battery, the Fe-Cu-NC catalyst manifested superior performance, with a top power density reaching 183.1 mW cm-2 and a specific capacity reaching 787 mAh g-1Zn. This study put forward a promising methodology to refine and boost the ORR activities of Fe-N-C-based catalysts with atomic dispersion.