@article{f8f823233654400695d47ce9b3ad2deb,
title = "Iridium Incorporation into MnO2 for an Enhanced Electrocatalytic Oxygen Evolution Reaction",
abstract = "We have investigated the structure and activity of electrocatalysts for the oxygen evolution reaction (OER) that had low loadings of Ir incorporated into the 2D layered MnO2, (birnessite, nominally δ-MnO2) and the 3D MnO2 (pyrolusite, β-MnO2). The Ir-incorporated β-MnO2 (Ir/β-MnO2) electrocatalysts were prepared for the first time via a thermally induced phase transition of δ-MnO2 containing 16–22 wt% Ir. This phase transition of δ-MnO2 to β-MnO2 was facilitated by the presence of Ir in the structure, as both Ir in IrO2 and Mn in β-MnO2 could adopt a thermodynamically favored rutile structure. Extended X-ray absorption fine structure (EXAFS) of Ir/β-MnO2 showed that the catalyst consisted of Ir substituted into the crystalline β-MnO2 lattice. 22 wt% Ir/β-MnO2 (60 (Formula presented.)) exhibited an OER overpotential ((Formula presented.)) of 337 mV, lower than the (Formula presented.) for commercial IrO2. This (Formula presented.) was constant for 6 h, at 10 mA (Formula presented.) in 0.5 M H2SO4. EXAFS, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray absorption near edge structure (XANES) showed that 22 wt% Ir/β-MnO2 had a strained structure containing ∼41 % Mn3+, an OER active species, along with a modified Ir bond covalency consisting of both Ir−O−Ir and Ir−O−Mn.",
keywords = "EXAFS, HAADF-STEM, iridium oxide, manganese oxide, oxygen evolution reaction",
author = "Uddipana Kakati and Elzinga, {Evert J.} and Mansley, {Zachary R.} and Benjamin Roe and Farbod Alimohammadi and Gregory Schwenk and Jinliang Ning and Yimei Zhu and Ji, {Hai Feng} and Jianwei Sun and Strongin, {Daniel R.}",
note = "Funding Information: This work was funded in part through Catalytic Collaborative Funding Initiative sponsored by the Office of Vice President for Research at Temple University. The electron microscopy work at Brookhaven National Laboratory was supported by U.S. DOE-BES, Materials Sciences and Engineering Division, under Contract No. DESC0012704. The use of the electron microscopy facility at CFN/BNL, which is a DOE-BES User Facility under the same contract number, is also acknowledged. The authors acknowledge Argonne National Laboratory for the use of Beamline 12BM at the Advanced Photon Source, a US Department of Energy Office of Science user facility operated for the DOE office of Science by Argonne National Laboratory under contract DE-AC02-06CH11357. We thank Sungsik Lee and Benjamin Reinhart for assistance with XAS data collection. Funding Information: This work was funded in part through Catalytic Collaborative Funding Initiative sponsored by the Office of Vice President for Research at Temple University. The electron microscopy work at Brookhaven National Laboratory was supported by U.S. DOE‐BES, Materials Sciences and Engineering Division, under Contract No. DESC0012704. The use of the electron microscopy facility at CFN/BNL, which is a DOE‐BES User Facility under the same contract number, is also acknowledged. The authors acknowledge Argonne National Laboratory for the use of Beamline 12BM at the Advanced Photon Source, a US Department of Energy Office of Science user facility operated for the DOE office of Science by Argonne National Laboratory under contract DE‐AC02‐06CH11357. We thank Sungsik Lee and Benjamin Reinhart for assistance with XAS data collection. Publisher Copyright: {\textcopyright} 2023 Wiley-VCH GmbH.",
year = "2023",
month = apr,
day = "21",
doi = "10.1002/cctc.202201549",
language = "English (US)",
volume = "15",
journal = "ChemCatChem",
issn = "1867-3880",
publisher = "Wiley - VCH Verlag GmbH & CO. KGaA",
number = "8",
}