Hydrogen adsorption and coadsorption with CO on well-defined bimetallic PtRu surfaces - a model study on the CO tolerance of bimetallic PtRu anode catalysts in low temperature polymer electrolyte fuel cells

被引：68

作者：

Diemant, T ^{[1
]}

Hager, T ^{[1
]}

Hoster, HE ^{[1
]}

Rauscher, H ^{[1
]}

Behm, RJ ^{[1
]}

机构：

[1] Univ Ulm, Abt Oberflachenchem & Katalyse, D-89069 Ulm, Germany

来源：

SURFACE SCIENCE | 2003年 / 541卷 / 1-3期

关键词：

adsorption kinetics; metallic surfaces; surface electronic phenomena (work function; surface potential; surface states; etc.); surface stress; alloys; ruthenium; platinum; thermal desorption; scanning tunneling microscopy; hydrogen molecule; deuterium; carbon monoxide;

D O I：

10.1016/S0039-6028(03)00915-4

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 influence of PtRu surface alloy formation and of coadsorbed CO on the adsorption/desorption characteristics of hydrogen on bimetallic PtRu surfaces was investigated by temperature programmed desorption, using a 40% Pt containing PtRu surface alloy pseudomorphic on a Ru(0001) surface with an almost statistical distribution of Pt surface atoms as substrate. Alloy formation leads to a significant broadening of the desorption peak compared to pure Ru, together with a considerable down-shift in the onset of desorption. This trend is even more pronounced in the presence of coadsorbed CO. The weakening of the hydrogen adsorption bond is attributed mainly to strain effects, imposed by the considerable compression of the pseudomorphic Pt as compared to bulk Pt(111). Finally we discuss the implications of these results for the mechanistic understanding of the improved performance of PtRu anode catalysts in reformate operated polymer electrolyte fuel cells. (C) 2003 Elsevier B.V. All rights reserved.

引用

页码：137 / 146

页数：10

共 42 条

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