The electronic structure of iridium and its oxides

dc.contributor.authorPfeifer, Verena
dc.contributor.authorJones, Travis E.
dc.contributor.authorVelasco Vélez, Juan J.
dc.contributor.authorMassué, Cyriac
dc.contributor.authorArrigo, Rosa
dc.contributor.authorTeschner, Detre
dc.contributor.authorGirgsdies, Frank
dc.contributor.authorScherzer, Michael
dc.contributor.authorGreiner, Mark T.
dc.contributor.authorAllan, Jasmin
dc.contributor.authorHashagen, Maike
dc.contributor.authorWeinberg, Gisela
dc.contributor.authorPiccinin, Simone
dc.contributor.authorHävecker, Michael
dc.contributor.authorKnop-Gericke, Axel
dc.contributor.authorSchlögl, Robert
dc.date.accessioned2017-04-25T13:23:43Z
dc.date.available2019-04-04T13:23:43Z
dc.date.issued2015
dc.description.abstractIridium-based materials are among the most active and stable electrocatalysts for the oxygen evolution reaction. Amorphous iridium oxide structures are found to be more active than their crystalline counterparts. Herein, we combine synchrotron-based Xray photoemission and absorption spectroscopies with theoretical calculations to investigate the electronic structure of Ir metal, rutile-type IrO2, and an amorphous IrOx. Theory and experiment show that while the Ir 4f line shape of Ir metal is well described by a simple Doniach–Šunji´c function, the peculiar line shape of rutile-type IrO2 requires the addition of a shake-up satellite 1 eV above the main line. In the catalytically more active amorphous IrOx, we find that additional intensity appears in the Ir 4f spectrum at higher binding energy when compared with rutile-type IrO2 along with a pre-edge feature in the OK-edge. We identify these additional features as electronic defects in the anionic and cationic frameworks, namely formally OI􀀀 and IrIII, which may explain the increased activity of amorphous IrOx electrocatalysts. We corroborate our findings by in situ X-ray diffraction as well as in situ X-ray photoemission and absorption spectroscopies.en
dc.identifier.eissn0142-2421
dc.identifier.issn1096-9918
dc.identifier.urihttp://depositonce.tu-berlin.de/handle/11303/6317
dc.identifier.urihttp://dx.doi.org/10.14279/depositonce-5873
dc.language.isoenen
dc.relation.ispartofhttp://dx.doi.org/10.14279/depositonce-5837
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.ddc541 Physikalische Chemiede
dc.subject.otheriridium oxideen
dc.subject.otherXPSen
dc.subject.otherDFTen
dc.subject.otherconduction electron screeningen
dc.subject.otherNEXAFSen
dc.titleThe electronic structure of iridium and its oxidesen
dc.typeArticleen
dc.type.versionacceptedVersionen
dcterms.bibliographicCitation.doi10.1002/sia.5895en
dcterms.bibliographicCitation.issue5
dcterms.bibliographicCitation.journaltitleSurface and interface analysisen
dcterms.bibliographicCitation.originalpublishernameWileyen
dcterms.bibliographicCitation.originalpublisherplaceChichester [u.a.]en
dcterms.bibliographicCitation.pageend273en
dcterms.bibliographicCitation.pagestart261en
dcterms.bibliographicCitation.volume48en
tub.accessrights.dnbdomainen
tub.affiliationFak. 2 Mathematik und Naturwissenschaften>Inst. Chemie>FG Technische Chemiede
tub.affiliation.facultyFak. 2 Mathematik und Naturwissenschaftende
tub.affiliation.groupFG Technische Chemiede
tub.affiliation.instituteInst. Chemiede
tub.publisher.universityorinstitutionTechnische Universität Berlinen
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