Hydrogen Peroxide Electrosynthesis Under Weak Thermodynamic Driving Conditions Enabled by In Situ Spin‐State Tailoring

Abstract Two‐electron oxygen reduction reaction (2e ⁻ ORR) offers a sustainable approach to traditional hydrogen peroxide (H ₂ O ₂ ) production, and can be scaled up in production capacity and efficiency through integrated energy conversion devices. Achieving the electrosynthesis of H ₂ O ₂ at low electrolytic cell voltages not only reduces energy consumption but also improves economic efficiency. Herein, we engineered the Ga sites as potential‐dependent spin‐state promoters at interatomic distances into highly active single‐atom Co sites. In this system, electron‐rich Ga atoms donate extra anti‐bonding orbital electrons to Co to induce an in situ transition of Co from a medium‐spin (0.70 V) to a low‐spin configuration (0.20 V), thereby facilitating smoother intermediates release. In parallel, Ga improves local hydrophilicity and surface polarity toward accelerated proton transfer. Impressively, the catalyst retains >90% H ₂ O ₂ selectivity even if the reaction enters the low‐voltage stage and enables a production rate of 13.7 mol g _cat ⁻¹ h ⁻¹ in a flow cell.