Dual-engineering of sulfur, oxygen co-doping and defective carbon structure boosts highly efficient hydrogen peroxide electrosynthesis.

Abstract

Utilizing the two-electron oxygen reduction reaction (2e^- ORR) for green hydrogen peroxide (H₂O₂) production offers a sustainable alternative to the traditional anthraquinone process. Metal-free carbon electrocatalysts have attracted significant attention due to their low cost and structural diversity. However, their advancement in 2e^- ORR has been severely hampered by the inefficient bulk production of H₂O₂. In this study, we report a dual-engineering strategy for enhancing H₂O₂ electroproduction by constructing a sulfur and oxygen (S, O) co-doped defective carbon electrocatalyst (HP-ACB). This HP-ACB electrocatalyst achieves a remarkable H₂O₂ kinetic current density of 184.3 A g^-1, a high Faradaic efficiency of 94 %, and enhanced H₂O₂ production reaching 8.21 mol g_cat^-1 h^-1. Experimental results with theoretical calculations demonstrate that the excellent electrocatalytic performance of HP-ACB in 2e^- ORR is attributed to the introduction of S, O atoms and defective carbon, which synergistically reduce the overpotential required for the adsorption of the key intermediate (OOH^⁎) on catalyst surface in 2e^- ORR. This research not only proposes a viable approach to enhancing the 2e^- ORR electrocatalytic activity of metal-free carbon materials but also highlights the importance of regulating the electronic structure of defective carbon in catalytic applications.