EDTA-Assisted Construction of NiSe2 Nanoparticles Confined in Porous N-Doped Carbon for Selective H2O2 Electrosynthesis in Alkaline Media

Hydrogen peroxide (H2O2) electrosynthesis via the two-electron oxygen reduction reaction (2e– ORR) is a promising alternative to the conventional anthraquinone process, but developing low-cost catalysts that simultaneously achieve high selectivity, productivity, and durability under alkaline conditions remains challenging. Herein, we report an EDTA-assisted coordination–annealing–selenization strategy for constructing NiSe2 nanoparticles confined in a porous N-doped carbon framework (NiSe2@N-C). In this design, EDTA-2Na serves as both a chelating ligand and a carbon/nitrogen source, enabling the formation of a conductive porous carbon scaffold that helps disperse NiSe2 nanoparticles and allows defect-related features to be tuned by annealing. In 0.1 M KOH, the optimized NiSe2@N-C catalyst achieves an H2O2 selectivity of up to 90% at 0.5 V vs RHE, an H2O2 production rate of 596 mmol g–1 h–1 at 0.3 V vs RHE, and a Faradaic efficiency of 85% at 0.3 V vs RHE. The catalyst also retains an H2O2 selectivity above 86% after 10,000 CV cycles under the tested conditions. Combined structural, electrochemical, and theoretical analyses suggest that annealing-governed defect-related features together with improved electrochemical accessibility contribute to the favorable 2e– ORR behavior. In addition, the relatively weak H2O2 reduction response may help suppress further peroxide loss under alkaline conditions. These results provide a useful basis for designing transition-metal selenide/carbon electrocatalysts for selective H2O2 electrosynthesis in alkaline media.