CO adsorption on epitaxially grown Pt layers on Ru (0001)

被引：48

作者：

Jakob, P.

Schlapka, A.

机构：

[1] Univ Marburg, Fachbereich Phys, D-35032 Marburg, Germany

[2] Univ Marburg, Wissensch Zentrum Mat Wissensch, D-35032 Marburg, Germany

[3] Tech Univ Munich, Dept Phys E20, D-85747 Garching, Germany

来源：

SURFACE SCIENCE | 2007年 / 601卷 / 17期

关键词：

vibrational spectroscopies; ruthenium; platinum; carbon monoxide; low index single crystal surfaces; epitaxy; surface stress;

D O I：

10.1016/j.susc.2007.06.035

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 adsorption of CO on epitaxially grown Pt films of variable thickness has been studied using infrared-absorption spectroscopy, scanning tunnelling microscopy and thermal desorption spectroscopy. Depending on the number of pseudomorphic Pt layers (N-Pt = 1-4) the internal and external CO stretching modes (v(C-O) and v(Pl-CO), respectively) display characteristic frequency shifts due to the vanishing influence of the underlying Ru(0 0 0 1) substrate and Pt/Ru interface. For thicker layers (N-Pt >= 5) when this influence has become negligible, the compressive stress within the Pt film is gradually relieved, leading to a dislocation network. The structural heterogeneity during the ongoing relaxation process of the Pt film is reflected in the v(C-O) line shape; no line broadening is observed for either pseudomorphic or very thick films (N-Pt >= 15). For N-Pt >= 3 the adsorption of CO on Pt/Ru(0 0 0 1) films closely resembles CO on Pt(1 1 1), with residual deviations in line position and desorption temperatures gradually converging to zero. (c) 2007 Elsevier B.V. All rights reserved.

引用

页码：3556 / 3568

页数：13

共 53 条

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