Stabilizing Trace Pt δ− Sites in NiFe Alloy–Hydroxide Heterostructure for Industrial‐Scale Alkaline Hydrogen Evolution

ABSTRACT Despite a great many modifications, Pt‐based catalysts are still suffering from the trade‐off among cost, activity, and stability, continuously limiting their widespread utilization in the hydrogen evolution reaction (HER). Herein, we proposed a PtNiFe‐NiFe LDH@NF catalyst constructed via in situ reduction of a NiFe alloy on a robust NiFe hydroxide, in which a trace amount of Pt (0.223 mg cm −2 ) was precisely incorporated into the alloy lattice through substitutional incorporation. This architecture effectively stabilizes the alloy phase and suppresses Pt agglomeration under industrial‐level current densities. Benefitting from strong interactions between Pt and Ni/Fe, a modified electron pathway from Ni/Fe to Pt facilitates unique electron‐rich Pt δ− species with a downshifted d‐band center, and better kinetics for intermediates evolution. Impressively, the PtNiFe‐NiFe LDH@NF delivers an overpotential of 48 mV at 100 mA cm −2 (5.89 times higher mass activity than that of commercial Pt/C) and superior durability of 1600 h at 1 A cm −2 , exhibiting more exceptional practicality than normal. Furthermore, the assembled anion exchange membrane electrolyzer achieves 1 A cm −2 at 1.76 V and maintains stability for 800 h, demonstrating an effective approach for efficient utilization of noble metal and access to industrial‐scaled HER catalysts.