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

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 Ru₂P, 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 Ir₂P and Ru₂P materials that promote fast cascade water dissociation and H₂ production via kinetically favorable hydrogen spillover from the Ru₂P surface to the adjacent Ir₂P. An unprecedented construction of Ir₂P cluster-decorated Ru₂P 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.