Corrosion-Tolerant Nickel Diselenide Architecture for Active and Durable Neutral H2O2 Electrosynthesis

Electrochemical production of hydrogen peroxide (H2O2) via the two-electron oxygen reduction reaction (2e– ORR) in neutral media is a promising alternative to the anthraquinone process, yet developing catalysts with simultaneously high activity and stability remains a significant challenge. Herein, we demonstrate that nickel diselenide (NiSe2) exhibits one of the highest 2e– ORR activities among nonprecious metal catalysts in neutral electrolytes, surpassing state-of-the-art materials. Combined spectroscopic analysis and density functional theory calculations reveal that the increased oxidation state of Ni in NiSe2 induces a d-band center downshift compared to NiSe. This electronic modulation optimizes the *OOH binding energy by preventing the overbinding observed in NiSe, thereby facilitating rapid H2O2 desorption. The inherent thermodynamic instability and resultant metal leaching were mitigated by designing a carbon-encapsulated architecture, with the conformal carbon shell affording enhanced durability by suppressing dissolution without compromising the high intrinsic activity of NiSe2. This study provides a rational design strategy for efficient transition-metal compounds by synergizing phase modulation and morphological protection.