Graphitic N in nitrogen-Doped carbon promotes hydrogen peroxide synthesis from electrocatalytic oxygen reduction

Abstract

Electrocatalytic two-electron oxygen reduction reaction (2e− ORR) is a promising strategy to achieve hydrogen peroxide (H2O2) production, which can replace the anthraquinone method in industrial processes. Nitrogen-doped carbon materials are active and selective electrocatalysts for 2e− ORR; however, it remains challenging to develop N-doped carbons for practical H2O2 production and pinpoint the exact role of nitrogen functionalities. Here, we examine covalent organic framework-derived nitrogen-doped carbons with well-defined porous structure and tunable N species for electrocatalytic H2O2 production. Electrochemical studies show their highest ORR activity and H2O2 selectivity of up to 75% in alkaline electrolyte. Notably, chronoamperometric bulk electrolysis achieves an unprecedented carbon-catalyzed H2O2 yield rate of 1286.9 mmol gcatalyst−1 h−1 and a faradaic efficiency of 69.8% at pH 13. X-ray photoelectron spectroscopy analysis combined with control experiments reveals that graphitic N is responsible for H2O2 production from 2e− ORR on N-doped carbons. Our work provides insights into the rational development of heteroatom-doped carbon electrocatalysts for efficient H2O2 generation.