Ru Doped Ir Nanowires for High‐Efficient and Durable Proton Exchange Membrane Water Electrolyzers

Abstract Long‐term operation of proton exchange membrane water electrolysis (PEMWE) poses significant challenges due to the high potential and strong acidic environment associated with the oxygen evolution reaction (OER), leading to severe catalyst degradation. Here, ultrafine iridium–ruthenium nanowires (IrRu NWs) are developed through a facile process, which exhibits excellent activity and stability for acidic OER. The IrRu NWs achieve an overpotential of 243 mV at 10 mA cm −2 , which is significantly lower than that of commercial IrO 2 and pure Ir nanowires. Importantly, the IrRu NWs demonstrate 17.6% higher current density at 2 V in real PEMWE device than that of the commercial IrO 2 and Pt/C catalysts at the anode and cathode, respectively. The PEMWE device with the IrRu NWs catalyst layers can be stably operated at 1.0 and 1.5 A cm −2 for more than 500 h with a degradation rate of only 28 µV h −1 , which makes the IrRu NWs a promising catalyst toward PEMWE applications.