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Free keywords:
nanoframe, oxygen evolution catalysis, Ru, stability, structurally-distorted, Electrocatalysts, Oxygen, Proton exchange membrane fuel cells (PEMFC), Stability, X ray absorption spectroscopy, Acidic conditions, Long duration, Nanoframes, Oxygen evolution, Oxygen evolution catalyse, Poor stability, Proton exchange membranes, Ru, Structurally-distorted, Water electrolysis, Catalysis
Abstract:
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. © 2023 Wiley-VCH GmbH.
