Misoriented high-entropy iridium ruthenium oxide for acidic water splitting

Designing an efficient catalyst for acidic oxygen evolution reaction (OER) is of critical importance in manipulating proton exchange membrane water electrolyzer (PEMWE) for hydrogen production. Here, we report a fast, nonequilibrium strategy to synthesize quinary high-entropy ruthenium iridium-based oxide (M-RuIrFeCoNiO 2 ) with abundant grain boundaries (GB), which exhibits a low overpotential of 189 millivolts at 10 milliamperes per square centimeter for OER in 0.5 M H 2 SO 4 . Microstructural analyses, density functional calculations, and isotope-labeled differential electrochemical mass spectroscopy measurements collectively reveal that the integration of foreign metal elements and GB is responsible for…

• NN
  National Natural Science Foundation of China

  Awards: U21A20327, 52122211, 22121001, 2017YFA0208200, 22025108
• JS
  Japan Society for the Promotion of Science

  Award: 22F22358