Zero anion crossover enables highly efficient simultaneous production of H2O2 at both cathode and anode

Coupling the two-electron water oxidation reaction and two-electron oxygen reduction reaction to ensure the concurrent production of H 2 O 2 can remarkably improve its current efficiency and production rate, which is the bottleneck for H 2 O 2 electrosynthesis. However, ion crossover between cathode and anode chambers may significantly restrain two-electron water oxidation reaction and two-electron oxygen reduction reaction. Herein, we report a zero anion crossover system for simultaneous production of H 2 O 2 enables an outstanding overall current efficiency of 156% and a high generation rate of 385 µmol min –1 . The substantially improved performance is resulted from confining the essential anions (e.g., HO 2 – ) for two-electron oxygen reduction reaction in the cathode and maintaining the high activity of CO 3 2− mediator for two-electron water oxidation reaction in the anode. This work underscores the importance of ion crossover in paired electrochemical synthesis cells and provides a practical approach to developing a highly efficient electrogeneration system for H 2 O 2 .