• • The Ir/WOx NSs achieve a mass activity of 2.34 A mgIr−1 at 300 mV overpotential, 11.1× and 9.8× higher than Ir NSs and commercial Ir/C, respectively, enabling significant reduction in Ir loading for cost-effective PEMWE deployment.
• • The catalyst exhibits a low overpotential of 216 mV at 10 mA cm−2geo, surpassing commercial IrO2 and indicating enhanced intrinsic activity for acidic OER.
• • In a PEM electrolyzer, Ir/WOx NSs deliver 1.0 A cm−2 at a cell voltage of 1.71 V, meeting ampere-level operational requirements for industrial hydrogen production.
• • Long-term stability tests show a potential decay rate of only 2.8 μV h−1, compared to 210 μV h−1 for commercial IrO2, under dynamic current densities (0.2–1.0 A cm−2), demonstrating robust durability essential for intermittent renewable energy integration.