[Advanced Materials] 我室黄小青教授发表论文:Structurally-Distorted RuIr-Based Nanoframes for Long-Duration Oxygen Evolution Catalysis

发布日期:2023年09月05日   浏览次数:

我室黄小青教授在 Advanced Materials 上发表论文:Structurally-Distorted RuIr-Based Nanoframes for Long-Duration Oxygen Evolution Catalysis

摘要:Oxygen evolution reaction (OER) plays a key role in proton exchange membrane water electrolysis, yet the electrocatalysts still suffer from the disadvantages of low activity and poor stability in acidic conditions. Here, we have successfully fabricated a new class of CdRu2IrOx nanoframes with distorted structure for acidic OER. Impressively, CdRu2IrOx displays an ultralow overpotential of 189 mV and an ultralong stability of 1500 h at 10 mA cm−2 towards OER in 0.5 M H2SO4, which has generally outperformed the reported catalysts (overpotential ∼200 mV and stability < 500 h in general). Moreover, a proton-exchange membrane water electrolyser (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 with shrunken Ru−O, Ir−O, and Ru−M (M = Ru, Ir) bonds 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 activity and stability of OER catalysts, which will attract immediate interests in diverse fields including materials, chemistry, and catalysis.