Oxygen Enrichment on Carbon Nanoreactors and *OOH Modulation on Sn₁ Sites Cooperatively Promote Industrial-Scale H₂O₂...

Industrial‑scale H₂O₂ electrosynthesis faces two major challenges: oxygen depletion at the catalytic interface, which causes diffusion limitations, and a strong dependence of product selectivity on the adsorption behavior of the *OOH intermediate. Constructing an O₂‑enriched microenvironment alleviates transport issues, while tuning *OOH adsorption prevents excessive O─O bond cleavage; their synergy is expected to boost ORR performance. Guided by theory, we developed a Sn single‑atom-anchored hollow mesoporous carbon nanoreactor (Sn₁/HMCS). The hollow mesoporous carbon nanoreactor facilitates an oxygen‑enriched microenvironment at the catalytic interface via spontaneous O₂ adsorption and diffusion, while the N/O‑coordinated Sn sites enable optimal *OOH adsorption regulation, delivering ∼100% H₂O₂ selectivity. The adaptive matching between the spontaneous oxygen supply kinetics and the electrocatalytic reaction allows the system to maintain both optimal thermodynamic potential and high selectivity at industrially relevant high‑current conditions. Assembling Sn₁/HMCS in a solid‑electrolyte cell delivered an industrial‑scale system for high‑purity H₂O₂ with low energy consumption and excellent stability. At 500 mA cm^{- 2}, it produced ∼4.51 wt% H₂O₂ at a rate of 31.8 mol g_catalyst ^{- 1} h^{- 1}, with stable operation over 300 h. This work provides a practical way to prepare catalysts meeting industrial‑scale current density requirements and facilitates the development of economically feasible H₂O₂ electrosynthesis schemes.