Activity and Durability of Iridium Nanoparticles in the Oxygen Evolution Reaction

Shaun Alia, Kenneth Neyerlin, Bryan Pivovar, Svitlana Pylypenko, Shyam Kocha

Research output: Contribution to journalArticlepeer-review

14 Scopus Citations


Unsupported iridium (Ir) nanoparticles, a benchmark catalyst in acidic electrolyzers, are investigated for oxygen evolution activity in rotating disk electrode (RDE) half-cells. Mercury underpotential deposition, used to evaluate the electrochemical surface areas (ECAs) of Ir, produces similar values prior to and following oxygen evolution testing and irreversible surface oxidation; stable ECA measurements allow for the study of site-specific activities prior to and following accelerated stress tests. Durability testing results in increasing activity losses due to particle growth at moderate potential and Ir dissolution at higher potential. Although the prolonged formation of oxygen bubbles may destabilize the catalyst layer, accelerated stress tests in hydrogen peroxide and formic acid confirm that the losses are primarily potential dependent. This study establishes RDE testing protocols for Ir in oxygen evolution. The observed durability losses have significant implications on acidic electrolyzers, particularly at low Ir loadings.

Original languageAmerican English
Pages (from-to)883-892
Number of pages10
JournalECS Transactions
Issue number17
StatePublished - 2015
EventSymposium on Polymer Electrolyte Fuel Cells 15, PEFC 2015 - 228th ECS Meeting - Phoenix, United States
Duration: 11 Oct 201515 Oct 2015

Bibliographical note

Publisher Copyright:
© The Electrochemical Society.

NREL Publication Number

  • NREL/JA-5900-65547


  • durability testing
  • iridium
  • nanoparticles
  • oxygen evolution


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