Preparation of Solid Solution and Layered IrO x-Ni(OH)2Oxygen Evolution Catalysts: Toward Optimizing Iridium Efficiency for OER

Jonathan Ruiz Esquius, Gerardo Algara-Siller, Ioannis Spanos, Simon J. Freakley, Robert Schlögl, Graham J. Hutchings

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36 Citations (SciVal)
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Minimizing iridium loading in oxygen evolution reaction (OER) catalysts, without impairing electrocatalytic activity and stability is crucial to reduce the cost of water electrolysis. In this work, two Ir0.5Ni0.5Ox mixed oxide catalysts with layered and solid solution morphologies were prepared by modifying a facile hydrothermal methodology. The catalytic OER activity and stability of the Ir-Ni catalyst with a homogeneous distribution (IrNi-HD) was seriously compromised compared to pure IrOx due to the high concentration of surface nickel prone to corrosion under reaction conditions. However, the design of layered IrOx-Ni(OH)x (IrNi-LY) with Ir at the exposed surface allowed a 50% reduction in the molar concentration of the precious metal on the electrode compared to IrOx without impairing the catalytic activity or stability. As a result, IrNi-LY outperformed IrOx in activity when normalized to the Ir mass.

Original languageEnglish
Pages (from-to)14640-14648
Number of pages9
JournalACS Catalysis
Issue number24
Early online date26 Nov 2020
Publication statusPublished - 18 Dec 2020

Bibliographical note

Funding Information:
We would like to show our gratitude to the MaxNet Energy research consortium for financial support. We would also like to thank Drs. Rosa Arrigo and Diego Gianolio from B18, Diamond Light Source at Harwell, for assisting us in the XAS spectroscopy experiment and providing the required sealed electrochemical cell. Finally, we would like to thank Dr. David J. Morgan for his assistance in XPS measurements.

Publisher Copyright:

Copyright 2020 Elsevier B.V., All rights reserved.


  • amorphous iridium oxo-hydroxide
  • electrocatalysis
  • hydrothermal synthesis
  • iridium nickel mixed oxide
  • iridium oxide
  • oxygen evolution reaction

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)


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