The electronic structure of iridium and its oxides

被引：340

作者：

Pfeifer, Verena ^{[1
,2
]}

Jones, Travis E. ^{[1
]}

Velez, Juan J. Velasco ^{[1
,3
]}

Massue, Cyriac ^{[1
,3
]}

Arrigo, Rosa ^{[4
]}

Teschner, Detre ^{[1
]}

Girgsdies, Frank ^{[1
]}

Scherzer, Michael ^{[1
,3
]}

Greiner, Mark T. ^{[1
]}

Allan, Jasmin ^{[1
]}

Hashagen, Maike ^{[1
]}

Weinberg, Gisela ^{[1
]}

Piccinin, Simone ^{[5
]}

Haevecker, Michael ^{[1
,3
]}

Knop-Gericke, Axel ^{[1
]}

Schloegl, Robert ^{[1
,3
]}

机构：

[1] Fritz Haber Inst, Max Planck Gesell, Faradayweg 4-6, D-14195 Berlin, Germany

[2] Helmholtz Zentrum Berlin Mat & Energie GmbH, Elektronenspeicherring BESSY II, Albert Einstein Str 15, D-12489 Berlin, Germany

[3] Max Planck Inst Chem Energiekonvers, Stiftstr 34-36, Mulheim Ad Ruhr, Germany

[4] Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England

[5] SISSA, CNR IOM, Via Bonomea 267, I-34136 Trieste, Italy

来源：

SURFACE AND INTERFACE ANALYSIS | 2016年 / 48卷 / 05期

关键词：

iridium oxide; XPS; NEXAFS; DFT; conduction electron screening; OXYGEN EVOLUTION; XPS; SPECTRA; SURFACE; NANOPARTICLES; CATALYSTS; SILVER; STATES; HOLES; ATOMS;

D O I：

10.1002/sia.5895

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Iridium-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 X-ray 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-Sunji function, the peculiar line shape of rutile-type IrO2 requires the addition of a shake-up satellite 1eV 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 O K-edge. We identify these additional features as electronic defects in the anionic and cationic frameworks, namely, formally OI- and Ir-III, 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. Copyright (c) 2015 John Wiley & Sons, Ltd.

引用

页码：261 / 273

页数：13