Tuning the Formation Kinetics of *OOH Intermediate with Hollow Bowl-Like Carbon by Pulsed Electroreduction for Enhanced H2O2 Production

Abstract

The electrochemical synthesis of hydrogen peroxide (H₂O₂) via the two-electron oxygen reduction reaction (2e^– ORR) is a promising alternative to the conventional anthraquinone method. However, due to local alkalinization near the catalyst surface, the restricted oxygen replenishment and insufficient activated water molecule supply limit the formation of the key *OOH intermediate. Herein, a pulsed electrocatalysis approach based on a structurally optimized S/N/O tridoped hollow carbon bowl catalyst has been proposed to overcome this challenge. In an H-type electrolytic cell, the pulsed method achieves a superior H₂O₂ yield rate of 55.6 mg h^–1 mg_cat.^–1, approximately 1.6 times higher than the conventional potentiostatic method (34.2 mg h^–1 mg_cat.^–1), while maintaining the Faradaic efficiency above 94.6%. In situ characterizations, finite element simulations, and density functional theory analyses unveil that the application of pulsed potentials mitigates the local OH^– concentration, enhances the water activation and proton generation, and facilitates oxygen production within the hollow bowl-like carbon structure. These effects synergistically accelerate the formation kinetics of the *OOH intermediate by the efficient generation of *O₂ and *H₂O intermediates, leading to superior H₂O₂ yields. This work develops a strategy to tune catalytic environments for diverse catalytic applications.