A Networked Catalytic Layer Derived from Composite Nanowires Integrated with Pt Core and Active Pt-Doped RuO ₂ Shell for Efficient Proton Exchange Membrane Water Electrolysis at Low Anode Loadings

The deployment of ruthenium-based catalysts in low-loading anodes of proton exchange membrane water electrolyzers is hindered by their insufficient stability and limited catalyst utilization. This work presents a novel core–shell nanowire electrocatalyst (PRO@Pt) consisting of a Pt nanowire core coated with a Pt-doped RuO 2 active shell. Characterization and theoretical calculations reveal that the incorporation of Pt dopants and the resulting lattice expansion elevate the electron density on Ru sites, weaken Ru–O covalency, and optimize intermediate adsorption, thereby enhancing the electrocatalytic activity and stability of RuO 2 for oxygen evolution reaction. In 0.5 M H 2 SO 4, PRO@Pt-2/18 exhibits a low overpotential of 173 mV at 10 mA cm –2 . Moreover, the catalyst network constructed by the intertwined PRO@Pt nanowire bundles avoids electrical isolation and ensures efficient electron transport throughout the electrode, even at a low loading. The single cell with the low-loading reticular catalyst layer (0.11 mg cm –2 ) conveys an extremely low voltage of 1.72 V at 3 A cm –2 and an average degradation rate of only 5 μV h –1 in the latter stage of 1450 h of operation. This study provides a new strategy for developing efficient and durable low-loading anodes for industrial water electrolysis.