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Vanadium oxide nanostructures on Rh(111): Promotion effect of CO adsorption and oxidation

Schoiswohl, J; Eck, S; Ramsey, MG; Andersen, Jesper N LU ; Surnev, S and Netzer, FP (2005) In Surface Science 580(1-3). p.122-136
Abstract
The adsorption of CO and the reaction of CO with pre-adsorbed oxygen at room temperature has been studied on the (2 x 1)O-Rh(1 1 1) surface and on vanadium oxide-Rh(1 1 1) "inverse model catalyst" surfaces using scanning tunnelling microscopy (STM) and core-level photoemission with synchrotron radiation. Two types of structurally well-defined model catalyst V3O9-Rh(1 1 1) surfaces have been prepared, which consist of large (mean size of similar to 50 nm, type I model catalyst) and small (mean size < 15 nm, type II model catalyst) two-dimensional oxide islands and bare Rh areas in between; the latter are covered by chemisorbed oxygen. Adsorption of CO on the oxygen pre-covered (2 x 1)O-Rh(1 1 1) surface leads to fast CO uptake in on-top... (More)
The adsorption of CO and the reaction of CO with pre-adsorbed oxygen at room temperature has been studied on the (2 x 1)O-Rh(1 1 1) surface and on vanadium oxide-Rh(1 1 1) "inverse model catalyst" surfaces using scanning tunnelling microscopy (STM) and core-level photoemission with synchrotron radiation. Two types of structurally well-defined model catalyst V3O9-Rh(1 1 1) surfaces have been prepared, which consist of large (mean size of similar to 50 nm, type I model catalyst) and small (mean size < 15 nm, type II model catalyst) two-dimensional oxide islands and bare Rh areas in between; the latter are covered by chemisorbed oxygen. Adsorption of CO on the oxygen pre-covered (2 x 1)O-Rh(1 1 1) surface leads to fast CO uptake in on-top sites and to the removal of half (0.25 ML) of the initial oxygen coverage by an oxidation clean-off reaction and as a result to the formation of a coadsorbed (2 x 2)-O + CO phase. Further removal of the adsorbed O with CO is kinetically hindered at room temperature. A similar kinetic behaviour has been found also for the CO adsorption and oxidation reaction on the type I "inverse model catalyst" surface. In contrast, on the type II inverse catalyst surface, containing small V-oxide islands, the rate of removal of the chemisorbed oxygen is significantly enhanced. In addition, a reduction of the V-oxide islands at their perimeter by CO has been observed, which is suggested to be the reason for the promotion of the CO oxidation reaction near the metal-oxide phase boundary. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
rhodium, catalysis, chemisorption, carbon monoxide, spectroscopy, scanning tunneling microscopy, synchrotron radiation photoelectron, vanadium oxide
in
Surface Science
volume
580
issue
1-3
pages
122 - 136
publisher
Elsevier
external identifiers
  • wos:000228544100015
  • scopus:15944384241
ISSN
0039-6028
DOI
10.1016/j.susc.2005.02.023
language
English
LU publication?
yes
id
cbfa5029-cc87-4cb8-9a63-7bbc5d6dbeae (old id 244595)
date added to LUP
2007-10-05 14:12:55
date last changed
2017-08-27 05:12:04
@article{cbfa5029-cc87-4cb8-9a63-7bbc5d6dbeae,
  abstract     = {The adsorption of CO and the reaction of CO with pre-adsorbed oxygen at room temperature has been studied on the (2 x 1)O-Rh(1 1 1) surface and on vanadium oxide-Rh(1 1 1) "inverse model catalyst" surfaces using scanning tunnelling microscopy (STM) and core-level photoemission with synchrotron radiation. Two types of structurally well-defined model catalyst V3O9-Rh(1 1 1) surfaces have been prepared, which consist of large (mean size of similar to 50 nm, type I model catalyst) and small (mean size &lt; 15 nm, type II model catalyst) two-dimensional oxide islands and bare Rh areas in between; the latter are covered by chemisorbed oxygen. Adsorption of CO on the oxygen pre-covered (2 x 1)O-Rh(1 1 1) surface leads to fast CO uptake in on-top sites and to the removal of half (0.25 ML) of the initial oxygen coverage by an oxidation clean-off reaction and as a result to the formation of a coadsorbed (2 x 2)-O + CO phase. Further removal of the adsorbed O with CO is kinetically hindered at room temperature. A similar kinetic behaviour has been found also for the CO adsorption and oxidation reaction on the type I "inverse model catalyst" surface. In contrast, on the type II inverse catalyst surface, containing small V-oxide islands, the rate of removal of the chemisorbed oxygen is significantly enhanced. In addition, a reduction of the V-oxide islands at their perimeter by CO has been observed, which is suggested to be the reason for the promotion of the CO oxidation reaction near the metal-oxide phase boundary.},
  author       = {Schoiswohl, J and Eck, S and Ramsey, MG and Andersen, Jesper N and Surnev, S and Netzer, FP},
  issn         = {0039-6028},
  keyword      = {rhodium,catalysis,chemisorption,carbon monoxide,spectroscopy,scanning tunneling microscopy,synchrotron radiation photoelectron,vanadium oxide},
  language     = {eng},
  number       = {1-3},
  pages        = {122--136},
  publisher    = {Elsevier},
  series       = {Surface Science},
  title        = {Vanadium oxide nanostructures on Rh(111): Promotion effect of CO adsorption and oxidation},
  url          = {http://dx.doi.org/10.1016/j.susc.2005.02.023},
  volume       = {580},
  year         = {2005},
}