Tailoring the Electronic Structure of Nickel With Ruthenium Nanocluster Arrays by Phosphorus Modification for Ampere‐Level Hydrogen Production

ABSTRACT Proton exchange membrane water electrolysis (PEMWE) requires Pt‐based hydrogen evolution reaction (HER) electrocatalysts, which makes current systems costly. Low‐cost alternatives have struggled to meet the requirements of both electrocatalytic activity and durability at high‐current density operations. Here, we developed phosphorus‐modified nickel with ruthenium nanoclusters self‐supported on carbon paper (P–NiRu/CP) as efficient HER electrocatalysts. By leveraging metal–organic framework precursors and optimizing the phosphidation process, a dynamic interface between Ru, Ni, and P exhibited optimized hydrogen adsorption/desorption energies and facilitated hydrogen mobility, promoting efficient Tafel recombination. The P–NiRu/CP exhibited an overpotential of 22 mV at 10 mA cm −2 and a Tafel slope of 29 mV dec −1 , outperforming benchmark Pt/C. Computational studies revealed that the dynamic interface in P–NiRu/CP enhanced the electrocatalytic activity. When employed as the cathode in a PEMWE single cell (with commercial IrO 2 as the anode) operating with pure deionized water, P–NiRu/CP achieved 2.05 V at 3.0 A cm −2 with stable operation over 500 h, highlighting P–NiRu/CP as a cost‐effective, durable, and scalable electrocatalyst for sustainable hydrogen production.