Trimetallic PtGaGe Sites on Metal-Deficient CoSe ₂ for Industrial-Grade Electrosynthesis of H ₂ O ₂ in Acidic Media

Traditional platinum-based alloys (such as Pt–Hg) can effectively suppress the 4-electron pathway to enhance the selectivity of hydrogen peroxide (H2O2), but they still face the issues of rapid dissolution in acid and excessively high costs due to Pt loading (>5 wt %). Herein, we developed a trimetallic PtGaGe catalyst anchored to a metal-deficient CoSe2 (md-CoSe2). The introduction of Ga and Ge effectively breaks the Pt–Pt bond to form Pt–Ga/Pt-Ge active sites, optimized the electronic structure of the d-band center of Pt, and improved the activity, selectivity and stability of 2e– ORR. The content of Pt in PtGaGe/md-CoSe2 is only 0.42 wt %, which greatly reduces the use of precious metals. The optimized PtGaGe/md-CoSe2 catalyst demonstrates good 2e– ORR performance. It shows an onset potential of 0.71 V vs RHE and a H2O2 selectivity of 91% at 0.2 V vs. RHE. At current densities of 50 mA·cm–2 and 100 mA·cm–2, the catalyst achieves industrially relevant H2O2 productivities of 943 mmol gcat.–1 h–1 and 1603.1 mmol gcat.–1 h–1, accompanied by corresponding Faraday efficiencies of 99% and 85%. This work pioneered the synergistic integration of multiatomic catalysts and defect engineering, providing a stable, high-performance solution for H2O2 production in acidic media.