Entropy‐Driven Engineering Enables Electron‐Enriched Pt for Industrial Hydrogen Evolution

Abstract Precise tailoring of the electronic structure of Pt catalysts remains a critical challenge for advancing hydrogen evolution reaction (HER) performance in proton exchange membrane water electrolysis (PEMWE). Herein, a novel entropy‐driven engineering strategy is proposed to regulate the electronic structure of Pt‐based catalysts and reveal an inverse volcano‐shaped relationship between support entropy and the Pt d ‐band center. Verifying by the proof‐of‐the‐concept medium‐entropy (FeCoNiMn) ₃ O ₄ spinel oxide (MESO) support, the electron transferred from MESO to Pt nanoparticles generates electron‐enriched Pt sites that downshift the d ‐band center, thereby drastically enhancing HER performance. The optimized Pt/(FeCoNiMn) ₃ O ₄ catalyst exhibits an ultra‐low overpotential of 10 mV and robust stability, placing it among the best Pt‐based catalysts. In a prototype PEMWE system, the newly developed electrocatalyst achieves 58.9 A mg _Pt ⁻¹ at 1.7 V, ≈4.5 times greater than commercial Pt/C. This work not only elucidates entropy‐driven engineering mechanisms but also provides a practical pathway for efficient hydrogen production.