Abstract The two‐electron oxygen reduction reaction (2e – ORR) enables sustainable electrochemical production of hydrogen peroxide (H 2 O 2 ), providing a green alternative to the traditional anthraquinone process. Herein, we report N/O dual‐doped hierarchically porous carbon nanoreactors (N/O‐HPCNs) derived from ZIF‐8 via a facile one‐step pyrolysis. The optimized catalyst achieves ∼90% H 2 O 2 selectivity over a wide potential range in 0.10 M KOH. Crucially, in a flow cell, N/O‐HPCNs deliver an industrial‐grade current density of 200 mA cm −2 with 92.8% Faradaic efficiency and a remarkable H 2 O 2 yield of 17.3 mol g −1 h −1 , while maintaining > 80% Faraday efficiency for 100 h. Finite element simulations confirm that hierarchical pores enhance mass transfer and reduce H 2 O 2 residence time, while DFT calculations elucidate the distinct roles of N doping for activity and oxygen functional groups in promoting 2e – ORR selectivity. This work provides a scalable strategy for sustainable H 2 O 2 production.