Bioinspired CoMn-Diatomic Superoxide Dismutase Nanozymes for High-Performance, Selective, and Long-Lasting H₂O₂ Production

The practical deployment of electrochemical hydrogen peroxide (H₂O₂) production is severely hampered by the corrosive superoxide radicals (O₂^•-) generated at industrial current densities via a one-electron-transfer process, which rapidly degrade active sites and catalysts, consequently deteriorating long-term stability. Inspired by the natural manganese superoxide dismutase (Mn-SOD) enzyme, we designed a biomimetic CoMn-diatomic catalyst (CoMn-DACs), where the Co-N₄ sites primarily drive the two-electron oxygen reduction reaction (2e^- ORR) for the selective H₂O₂ production, while the adjacent Mn-N₄ sites function as SOD-mimetic nanozymes, efficiently reversely converting O₂^•- radicals into H₂O₂, thus bypassing the destructive reaction pathway. Combined operando spectroscopy and density functional theory calculations reveal the dual functions of Mn sites in facilitating O₂^•- conversion and optimizing the *OOH adsorption energy on Co centers via the Co-Mn orbital coupling, which induces electronic structure redistribution and moderates the interaction between Co sites and oxygen intermediates toward highly selective and stable H₂O₂ production. Correspondingly, bioinspired CoMn-DACs achieve 99.3% H₂O₂ selectivity with an onset potential of 0.83 V (vs. RHE) and a maximum H₂O₂ production rate of 6.35 mM mg_cat^-1, surpassing the state-of-the-art catalyst, while maintaining 83.0-85.1% FE during 200 h continuous operation at 200 mA cm^-2. A techno-economic analysis confirms the practical viability of this system, projecting a low H₂O₂ production cost of US$0.371 kg^-1 when operated directly with ambient air, significantly outperforming the conventional anthraquinone process (US$1.50 kg^-1). This work achieves durable electrosynthesis by emulating natural radical defense mechanisms, enabling enhanced stability and selectivity in energy-efficient H₂O₂ production.