STM investigation of the (2x2)O and (2x1)O structures on Rh(111)

被引：9

作者：

Marchini, S ^{[1
]}

Sachs, C ^{[1
]}

Wintterlin, J ^{[1
]}

机构：

[1] Univ Munich, Dept Chem, D-81377 Munich, Germany

来源：

SURFACE SCIENCE | 2005年 / 592卷 / 1-3期

关键词：

scanning tunneling microscopy; chemisorption; rhodium; oxygen; carbon monoxide; low index single crystal surfaces;

D O I：

10.1016/j.susc.2005.06.080

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 oxygen on Rh(1 1 1) was investigated by STM. Dosing of O-2 on the Rh(1 1 1) surface at 300 K until saturation leads to a (2 x 1)O structure with an O coverage of 0.5. The (2 x 1)O structure forms large, well-ordered domains. After lower O-2 exposures a (2 x 2)O structure with an O coverage of 0.25 could be resolved at low temperatures, whereas at 300 K disordering and the high mobility prevented resolution of oxygen. The O atoms quickly react with H-2 at 300 K, but no similar low temperature reaction channel as on Pt(1 1 1) was observed. Under slightly worse vacuum conditions a different (2 x 2) structure was observed that does no longer transform into the (2 x 1)O structure at higher O-2 exposures. This structure, which is not reactive with H-2 and displays CO and CO2 desorption in TDS, is interpreted as the (2 x 2)O + CO structure. Its formation by unintended coadsorption of CO can explain controversial observations in previous work. (c) 2005 Elsevier B.V. All rights reserved.

引用

页码：58 / 64

页数：7

共 35 条

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