Structurally‐Distorted RuIr‐Based Nanoframes for Long‐Duration Oxygen Evolution Catalysis

Oxygen evolution reaction (OER) plays a key role in proton exchange membrane water electrolysis (PEMWE), yet the electrocatalysts still suffer from the disadvantages of low activity and poor stability in acidic conditions. Here, a new class of CdRu2IrOx nanoframes with distorted structure for acidic OER is successfully fabricated. Impressively, CdRu2IrOx displays an ultralow overpotential of 189 mV and an ultralong stability of 1500 h at 10 mA cm⁻2 toward OER in 0.5 M H2SO4. Moreover, a PEMWE using the distorted CdRu2IrOx can be steadily operated at 0.1 A cm⁻2 for 90 h. Microstructural analyses and X‐ray absorption spectroscopy (XAS) demonstrate that the synergy between Ru and Ir in CdRu2IrOx induces the distortion of Ru−O, Ir−O, and Ru−M (M = Ru, Ir) bonds. In situ XAS indicates that the applied potential leads to the deformation octahedral structure of RuOx/IrOx and the formation of stable Ru5+ species for OER. Theoretical calculations also reveal that the distorted structures can reduce the energy barrier of rate‐limiting step during OER. This work provides an efficient strategy for constructing structural distortion to achieve significant enhancement on the activity and stability of OER catalysts. Structurally‐distorted CdRu2IrOx nanoframes with twisted Ru−O, Ir−O, and Ru–M (M = Ru, Ir) are successfully constructed via cation exchange and sequential thermal treatment, which can be used as ultra‐active and ultra‐stable acidic OER catalyst due to the strong synergy between Ru and Ir.