Adjusted MnO oxygen vacancy for highly selective ORR production of H2O2

Abstract

The oxygen reduction reaction (ORR) via the two-electron pathway is an important method of hydrogen peroxide (H₂O₂) production. This study demonstrates that MnO with different oxygen vacancies possesses great 2e⁻ ORR activity. The H₂O₂ selectivity increased from 10% to 93% with increasing oxygen vacancy concentration by adjusting the reaction temperature and time. Moreover, the H₂O₂ yield of the optimal MnO reached 544.1 mmol g⁻¹ h⁻¹, and it showed extraordinary stability over a long period of time (10 000 circles CV), surpassing most of the reported transition metal catalysts. This provides a new strategy for efficient and low-cost electrochemical production of H₂O₂.