In situ X-ray probing reveals fingerprints of surface platinum oxide

被引：98

作者：

Friebel, Daniel ^{[1
]}

Miller, Daniel J. ^{[1
]}

O'Grady, Christopher P. ^{[1
]}

Anniyev, Toyli ^{[1
]}

Bargar, John ^{[1
]}

Bergmann, Uwe ^{[1
]}

Ogasawara, Hirohito ^{[1
]}

Wikfeldt, Kjartan Thor ^{[2
]}

Pettersson, Lars G. M. ^{[2
]}

Nilsson, Anders ^{[1
]}

机构：

[1] SLAC Natl Accelerator Lab, Menlo Pk, CA 94025 USA

[2] Stockholm Univ, AlbaNova Univ Ctr, FYSIKUM, S-10691 Stockholm, Sweden

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2011年 / 13卷 / 01期

关键词：

OXYGEN-REDUCTION ELECTROCATALYSTS; HIGH-COVERAGE STRUCTURES; MONOLAYER ELECTROCATALYSTS; FUEL-CELL; ABSORPTION SPECTROSCOPY; ADSORPTION SITES; CLUSTERS; PT(111); NANOPARTICLES; XAS;

D O I：

10.1039/c0cp01434f

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：

In situ X-ray absorption spectroscopy (XAS) at the Pt L(3) edge is a useful probe for Pt-O interactions at polymer electrolyte membrane fuel cell (PEMFC) cathodes. We show that XAS using the high energy resolution fluorescence detection (HERFD) mode, applied to a well-defined monolayer Pt/Rh(111) sample where the bulk penetrating hard X-rays probe only surface Pt atoms, provides a unique sensitivity to structure and chemical bonding at the Pt-electrolyte interface. Ab initio multiple-scattering calculations using the FEFF code and complementary extended X-ray absorption fine structure (EXAFS) results indicate that the commonly observed large increase of the white-line at high electrochemical potentials on PEMFC cathodes originates from platinum oxide formation, whereas previously proposed chemisorbed oxygen-containing species merely give rise to subtle spectral changes.

引用

页码：262 / 266

页数：5

共 43 条

[1] DIRECT OBSERVATION OF SURFACE OXIDE FORMATION AND REDUCTION ON PLATINUM CLUSTERS BY TIME-RESOLVED X-RAY-ABSORPTION SPECTROSCOPY [J].