Interfacial Electronic Modulation of Vacancy‐Stabilized Pt Sites in Mo‐NiSeO 4 /NiSe 2 Heterostructures for Industrial Alkaline Water Electrolysis

ABSTRACT Developing bifunctional electrocatalysts that combine high activity, long‐term durability, and practical device compatibility remains a major challenge for alkaline water electrolysis. Herein, we report a heterostructure catalyst of a conductive Co 2 P nanowire scaffold integrated with a Mo‐regulated NiSeO 4 /NiSe 2 heterophase shell, and atomically dispersed Pt species stabilized at O/Se‐coordinated vacancy sites (Pt,Mo‐NiSeO 4 /NiSe 2 @Co 2 P) grown on nickel foam via sequential electrodeposition, controlled selenization, and galvanic replacement. Benefiting from synergistic electronic modulation and heterointerface engineering, the catalyst requires only 24 and 98 mV to deliver 10 and 100 mA cm −2 for the hydrogen evolution reaction, and 242 and 330 mV for the oxygen evolution reaction, in 1.0 M KOH, with excellent durability. Operando Raman spectroscopy and X‐ray absorption spectroscopy reveal dynamic surface evolution during electrocatalysis and confirm the atomic dispersion of Pt. When assembled in a two‐electrode electrolyzer, the catalyst achieves cell voltages of 1.47 V at 10 mA cm −2 and 1.65 V at 100 mA cm −2 in 30 wt.% KOH. Furthermore, an anion exchange membrane water electrolyzer delivers 1.55 V at 0.3 A cm −2 and 1.76 V at 1.0 A cm −2 at 70 °C, demonstrating its promise for practical alkaline hydrogen production.