Abstract Efficient and durable electrocatalysts toward alkaline hydrogen evolution reaction (HER) are of great significance for the widespread application of anion‐exchange membrane water electrolyzer (AEMWE). Numerous single‐phase catalysts, such as Ru 2 P, have been explored as efficient HER catalysts; however, many have failed to overcome the inherent sluggish kinetics of the two separate steps involved in the alkaline HER: water dissociation and hydrogen production. In this study, density functional theory calculations are conducted to identify promising combinations of Ir 2 P and Ru 2 P materials that promote fast cascade water dissociation and H 2 production via kinetically favorable hydrogen spillover from the Ru 2 P surface to the adjacent Ir 2 P. An unprecedented construction of Ir 2 P cluster‐decorated Ru 2 P hollow nanotubes ( c ‐RP/IP HNTs), which feature a cooperative heterostructural synergy are developed. This configuration shows greater performance than commercial Pt/C, achieving an overpotential of 23.2 mV at 10 mA cm − 2 and maintaining long‐term stability for 55 h in half‐cell tests. Furthermore, the practical AEMWE test, incorporating c ‐RP/IP HNTs, demonstrated a remarkable single‐cell performance of 12.23 A cm −2 at 2.0 V and operated stably under 1.0 A cm −2 for over 250 h. This surpasses that of the state‐of‐the‐art proton‐exchange membrane WE.

Ru2P/Ir2P Heterostructure Promotes Hydrogen Spillover for Efficient Alkaline Hydrogen Evolution Reaction