@article{d4ab7d32df104905866b2ed6d16e1190,
title = "Constant Change: Exploring Dynamic Oxygen Evolution Reaction Catalysis and Material Transformations in Strontium Zinc Iridate Perovskite in Acid",
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.",
author = "Jane Edgington and Neil Schweitzer and Selim Alayoglu and Seitz, {Linsey C.}",
note = "Funding Information: Funding from Northwestern University is gratefully acknowledged. J.E. acknowledges support from the National Science Foundation under Grant No. DGE-1842165. Funding Information: This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Extraordinary facility operations were supported in part by the DOE Office of Science through the National Virtual Biotechnology Laboratory, a consortium of DOE national laboratories focused on the response to COVID-19, with funding provided by the Coronavirus CARES Act. MRCAT operations are supported by the Department of Energy and the MRCAT member institutions. This work made use of the NUFAB facility of Northwestern University{\textquoteright}s NUANCE Center, which has received support from the SHyNE Resource (NSF ECCS-2025633), the IIN, and Northwestern{\textquoteright}s MRSEC program (NSF DMR-1720139). Metal analysis was performed at the Northwestern University Quantitative Bioelement Imaging Center. This work made use of the Jerome B.Cohen X-ray Diffraction Facility supported by the MRSEC program of the National Science Foundation (DMR-1720139) at the Materials Research Center of Northwestern University and the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205.) REACT acknowledged funding from Northwestern University Office of Research for purchase of the Micromeritics 3Flex instrument. The authors graciously acknowledge the help of Rebecca Sponenburg for her assistance with metal analysis at the Northwestern University Quantitative Bioelement Imaging Center. The authors also graciously acknowledge the assistance of Joshua Wright, Mark Warren, Carlo Segre, Denis Keane, and Qing Ma with XAS experimentation at the Advanced Photon Source. Publisher Copyright: {\textcopyright} 2021 American Chemical Society.",
year = "2021",
month = jul,
day = "7",
doi = "10.1021/jacs.1c04332",
language = "English (US)",
volume = "143",
pages = "9961--9971",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "26",
}