Cu–N–C support confinement stabilizes active Co sites in oxygen reduction reaction

Strengthening the operational durability of oxygen reduction reaction (ORR) catalysts are essential for advancing both fuel cells and metal-air batteries. However, developing highly active and durable catalysts remains a significant challenging. In this study, a catalyst (Co/Cu-N-C) featuring uniformly distributed Co nanoparticles (NPs) and Co/Cu sites has been synthesized via a facile complex-assisted pyrolysis strategy. We observe that Cu-N-C support effectively confines the growth and leaching of Co NPs during both synthesis and ORR catalysis, thereby boosting the stability of the catalyst. Meanwhile, the presence of Co NPs and Cu sites slightly contributes to the ORR activity by optimizing the *OH desorption. The assembled zinc-air battery (ZAB) demonstrates a superhigh power density of 256.1 mW cm^-2 and a long-term operational stability exceeding 500 h. This work not only underscores the potential of bimetallic systems and NPs in enhancing catalyst stability but also provides valuable insights for the synthesis of high-performance ORR electrocatalysts.