Crystal OH mediating pathway for hydrogen peroxide production via two-electron water oxidation in non-carbonate electrolytes

Water oxidation presents a promising avenue for hydrogen peroxide (H 2 O 2 ) production. However, the reliance on alkaline bicarbonate electrolytes as an intermediate has limitations, such as H 2 O 2 decomposition and a narrow pH effectiveness range (7–9), restricting its utility across wider pH ranges. This study unveils a crystal OH mediating pathway that stabilizes SO 4 OH* as a crucial intermediate. Basic copper carbonate (Cu 2 (OH) 2 CO 3 ) tablets, commonly found on cultural relics, exhibit the capability to generate H 2 O 2 in neutral or acidic non-bicarbonate electrolytes. By leveraging this crystal OH mediating strategy, considerable H 2 O 2 production in Na 2 SO 4 electrolytes is achievable. Notably, the H 2 O 2 production rate can reach 64.35 μmol h −1 at 3.4 V vs. RHE in a 50 mL 0.5 M Na 2 SO 4 electrolyte. This research underscores the importance of crystal part in catalyst in catalyzing the 2e − water oxidation reaction, offering valuable insights for future investigations.