EDTA-Assisted Construction of NiSe ₂ Nanoparticles Confined in Porous N-Doped Carbon for Selective H ₂ O ₂ Electrosynthesis in Alkaline Media

Hydrogen peroxide (H 2 O 2 ) 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 NiSe 2 nanoparticles confined in a porous N-doped carbon framework (NiSe 2 @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 NiSe 2 nanoparticles and allows defect-related features to be tuned by annealing. In 0.1 M KOH, the optimized NiSe 2 @N-C catalyst achieves an H 2 O 2 selectivity of up to 90% at 0.5 V vs RHE, an H 2 O 2 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 H 2 O 2 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 H 2 O 2 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 H 2 O 2 electrosynthesis in alkaline media.