Constant Change: Exploring Dynamic Oxygen Evolution Reaction Catalysis and Material Transformations in Strontium Zinc Iridate Perovskite in Acid

Jane Edgington, Neil Schweitzer, Selim Alayoglu, Linsey C. Seitz*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

While iridium-based perovskites have been identified as promising candidates for the oxygen evolution reaction (OER) in proton exchange membrane (PEM) electrolyzer applications, an improved fundamental understanding of these highly dynamic materials under reaction conditions is needed to inform more robust future catalyst design. Herein, we study the highly active SrIr0.8Zn0.2O3 perovskite for the OER in acid by employing electrochemical experiments with in situ and ex situ characterization techniques to understand the dynamic nature of this material at both short and long time scales. We observe initial intrinsic OER activity improvement with electrochemical cycling as well as an initial increase of Ir oxidation state under OER conditions via in situ X-ray absorption spectroscopy. We discover that the SrIr0.8Zn0.2O3 perovskite experiences an OER-induced metal to insulator transition (MIT) with extensive electrochemical cycling, caused by surface reorganization and changes to the material crystallinity that occur with exposure to an acidic and oxidizing environment. Our novel identification of an OER-induced MIT for iridate perovskites reveals an additional stability concern for iridate catalysts which are known to experience material dissolution challenges; this work ultimately aims to inform future catalyst material design for PEM water electrolysis applications.

Original languageEnglish (US)
Pages (from-to)9961-9971
Number of pages11
JournalJournal of the American Chemical Society
Volume143
Issue number26
DOIs
StatePublished - Jul 7 2021

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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