Accelerating OH − Transport for 5000‐Hour‐Stable Kilowatt‐Scale Alkaline Water Electrolysis

ABSTRACT Enhancing the continuous supply of OH − reactants to anode catalytic sites under high current density is critical for the development of alkaline water electrolyzer (AWE). Herein, a strategy for promoting OH − transport is demonstrated by using rare earth oxide clusters (REO x ) to reconfigure interfacial hydrogen bond networks. This structural modulation achieves a nearly threefold increase in the OH − transport rate. Mechanistic analysis reveals that the incorporation of rare earth weakens the charge‐dipole interaction between the oxygen in the * OH intermediate and interfacial H 2 O molecules, promoting the transition from a rigid, ordered interfacial water structure to a more isolated, loose configuration. A linear correlation among the proportions of isolated water species, OH − transport rates, and OER activity across a series of REO x /NiCo 2 S 4 catalysts supports this mechanism. A kilowatt‐scale AWE consisting of 17 cells with a total active area of 1334 cm 2 was assembled using a DyO x /NiCo 2 S 4 anode. For the first time, the system operated stably for over 5,000 h at a current of 39.25 A under industrial operating conditions, achieving a cumulative hydrogen output of 1,400 Nm 3 . This work highlights the potential of manipulating the electrode‐electrolyte interface to enhance catalyst performance in producing industrial‐scale green hydrogen.