XPS and STM studies of the oxidation of hydrogen chloride at Cu(100) surfaces
File(s)
Published version
Author(s)
Altass, H
Carley, AF
Davies, PR
Davies, RJ
Type
Journal Article
Abstract
The dissociative chemisorption of HCl on clean and oxidized Cu(100) surfaces has been investigated using x-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). Whereas the dissociation of HCl at the clean surface is limited to the formation of a (√ 2 × √ 2)-R45° Cl(a) monolayer, the presence of surface oxygen removes this barrier, leading to chlorine coverages up to twice that obtained at the clean surface. Additional features in the STM images that appear at these coverages are tentatively assigned to the nucleation of CuCl islands. The rate of reaction of the HCl was slightly higher on the oxidized surface but unaffected by the initial oxygen concentration or the availability of clean copper sites. Of the two distinct domains of adsorbed oxygen identified at room temperature on the Cu(100) surfaces, the (√ 2 × √ 2)-R45° structure reacts slightly faster with HCl than the missing row (√ 2 × 2 √ 2)-R45° O(a) structure. The results address the first stages in the formation of a copper chloride and present an interesting comparison with the HCl/O(a) reaction at Cu(110) surfaces, where oxygen also increased the extent of HCl reactions. The results emphasize the importance of the exothermic reaction to form water in the HCl/O(a) reaction on copper.
Date Issued
2015-12-29
Date Acceptance
2015-12-29
Citation
Surface Science, 2015, 650, pp.177-186
ISSN
0039-6028
Publisher
Elsevier
Start Page
177
End Page
186
Journal / Book Title
Surface Science
Volume
650
Copyright Statement
© 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/).
(http://creativecommons.org/licenses/by/4.0/).
License URL
Subjects
Science & Technology
Physical Sciences
Chemistry, Physical
Physics, Condensed Matter
Chemistry
Physics
HCl
Cu(100)
Oxidation
Chlorination
XPS
Copper chloride
SCANNING-TUNNELING-MICROSCOPY
CONTROLLING REACTION SELECTIVITY
RAY PHOTOELECTRON-SPECTROSCOPY
CU(110) SURFACES
ATOMIC OXYGEN
FORMIC-ACID
ACTIVATION
ADSORPTION
HCL
METHANOL
Chemical Physics
0204 Condensed Matter Physics
0206 Quantum Physics
0306 Physical Chemistry (Incl. Structural)
Publication Status
Published