Surface Ir+5 Formation as a Universal Prerequisite for O2 Evolution on Ir Oxides

被引：24

作者：

Diklic, Natasa ^{[1
]}

Clark, Adam H. H. ^{[1
]}

Herranz, Juan ^{[1
]}

Aegerter, Dino ^{[1
]}

Diercks, Justus S. S. ^{[1
]}

Beard, Alexandra ^{[1
]}

Saveleva, Viktoriia A. A. ^{[1
]}

Chauhan, Piyush ^{[1
]}

Nachtegaal, Maarten ^{[1
]}

Huthwelker, Thomas ^{[1
]}

Lebedev, Dmitry ^{[2
,3
]}

Kayser, Paula ^{[4
]}

Antonio Alonso, Jose ^{[4
]}

Coperet, Christophe ^{[2
]}

Schmidt, Thomas J. J. ^{[1
,5
]}

机构：

[1] Paul Scherrer Inst, CH-5232 Villigen, Switzerland

[2] Swiss Fed Inst Technol, Dept Chem & Appl Biosci, CH-8093 Zurich, Switzerland

[3] Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA

[4] CSIC, Inst Ciencia Mat Madrid, Madrid 28049, Spain

[5] Swiss Fed Inst Technol, Lab Phys Chem, CH-8093 Zurich, Switzerland

来源：

ACS CATALYSIS | 2023年 / 13卷 / 16期

关键词：

OER; IrO2; catalysts; electrochemistry; operando XAS; modulation excitation XAS; X-RAY-ABSORPTION; ENHANCED RAMAN-SPECTROSCOPY; OXYGEN EVOLUTION; IN-SITU; IRIDIUM OXIDE; WATER-OXIDATION; ELECTRONIC-STRUCTURE; ADSORPTION SITES; PARTICLE-SIZE; OPERANDO XAS;

D O I：

10.1021/acscatal.3c01448

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：

The large-scale deployment of polymer electrolyte waterelectrolysis(PEWE) is largely limited by the use of O-2 evolution reaction(OER) catalysts based on scarce and expensive iridium in PEWE anodes.The ensuing need for better-performing, Ir-based OER catalysts requiresan improved understanding of the relation between these materials'activity and their physicochemical operando properties.To shed light on this matter, here, we employed operando modulation excitation X-ray absorption spectroscopy to determinethe oxidation state of surface Ir in a range of Ir oxides with differentsurface compositions, crystal structures, and OER activities. Ourresults reveal that, irrespectively of these diverging properties,the surface Ir in all catalysts systematically undergoes a linear,potential-driven oxidation that stabilizes once a +5 state is reached.The completion of this surface oxidation process is then showed tocorrelate with the onset of O-2 evolution, thus stronglyhinting at the involvement of Ir in oxidation states & GE;+5 inthe OER and indirectly discarding those mechanisms that do not considersuch states as a part of the reaction sequence.

引用

页码：11069 / 11079

页数：11

共 71 条

[1] Iridium Oxide for the Oxygen Evolution Reaction: Correlation between Particle Size, Morphology, and the Surface Hydroxo Layer from Operando XAS [J].