Efficient and economic H2O2 electrosynthesis via two-electron oxygen reduction reaction enabled by dynamically reconstructed Mn(*OH)-N3O-C motif and coupled alcohol oxidation

Abstract

Hydrogen peroxide (H₂O₂) electrosynthesis via two-electron oxygen reduction reaction (2e⁻ ORR) is a promising alternative for the energy-intensive anthraquinone process. However, the instability of the catalytic metal sites in the state-of-the-art metal single-atom catalysts (M-SACs) hinders their further industrial applications, and the high potential and valueless oxygen product of the conventional anodic oxygen evolution reaction (OER) further limit the economic efficiency of this technology. To address this, a dynamically local structure reconstruction strategy is proposed to in situ transfer the active sites from unstable metal sites to the stable surrounding carbon sites for efficient and durable 2e⁻ ORR electrocatalysis. For the as-designed Mn-N₃O-C catalyst, by reconstructing Mn sites into Mn(*OH), the Mn sites were passivated and carbon sites adjacent to the O atom were verified to be the actual active sites by in situ characterization and theoretical calculation. Consequently, Mn-N₃O-C exhibited > 80% Faradaic efficiency and superior long-term durability over 100 h for H₂O₂ electrosynthesis at ∼120 mA cm⁻². In addition, coupling anodic ethylene glycol oxidation reaction (EGOR) further improves the efficiency and economic viability of the H₂O₂ electrosynthesis system. This two-pronged strategy thus opens up a new opportunity for the development of stable H₂O₂ electrosynthesis with low energy consumption and superior economic performance.