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Dissociation of water on oxygen-covered Rh{111}

Shavorskiy, A.; Eralp, T.; Ataman, Evren LU ; Isvoranu, Cristina LU ; Schnadt, Joachim LU ; Andersen, Jesper N LU and Held, G. (2009) In Journal of Chemical Physics 131(21).
Abstract
The adsorption of water and coadsorption with oxygen on Rh{111} under ultrahigh vacuum conditions was studied using synchrotron-based photoemission and photoabsorption spectroscopy. Water adsorbs intact on the clean surface at temperatures below 154 K. Irradiation with x-rays, however, induces fast dissociation and the formation of a mixed OH+H2O layer indicating that the partially dissociated layer is thermodynamically more stable. Coadsorption of water and oxygen at a coverage below 0.3 monolayers has a similar effect, leading to the formation of a hydrogen-bonded network of water and hydroxyl molecules at a ratio of 3:2. The partially dissociated layers are more stable than chemisorbed intact water with the maximum desorption... (More)
The adsorption of water and coadsorption with oxygen on Rh{111} under ultrahigh vacuum conditions was studied using synchrotron-based photoemission and photoabsorption spectroscopy. Water adsorbs intact on the clean surface at temperatures below 154 K. Irradiation with x-rays, however, induces fast dissociation and the formation of a mixed OH+H2O layer indicating that the partially dissociated layer is thermodynamically more stable. Coadsorption of water and oxygen at a coverage below 0.3 monolayers has a similar effect, leading to the formation of a hydrogen-bonded network of water and hydroxyl molecules at a ratio of 3:2. The partially dissociated layers are more stable than chemisorbed intact water with the maximum desorption temperatures up to 30 K higher. For higher oxygen coverage, up to 0.5 monolayers, water does not dissociate and an intact water species is observed above 160 K, which is characterized by an O 1s binding energy 0.6 eV higher than that of chemisorbed water and a high desorption temperature similar to the partially dissociated layer. The extra stabilization is most likely due to hydrogen bonds with atomic oxygen. (C) 2009 American Institute of Physics. [doi:10.1063/1.3266941] (Less)
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publication status
published
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in
Journal of Chemical Physics
volume
131
issue
21
publisher
American Institute of Physics
external identifiers
  • wos:000272494300032
  • scopus:72049122683
ISSN
0021-9606
DOI
10.1063/1.3266941
language
English
LU publication?
yes
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49c5bef0-6567-4617-9a58-0142dd961160 (old id 1533483)
date added to LUP
2010-01-27 16:26:22
date last changed
2017-03-26 03:43:54
@article{49c5bef0-6567-4617-9a58-0142dd961160,
  abstract     = {The adsorption of water and coadsorption with oxygen on Rh{111} under ultrahigh vacuum conditions was studied using synchrotron-based photoemission and photoabsorption spectroscopy. Water adsorbs intact on the clean surface at temperatures below 154 K. Irradiation with x-rays, however, induces fast dissociation and the formation of a mixed OH+H2O layer indicating that the partially dissociated layer is thermodynamically more stable. Coadsorption of water and oxygen at a coverage below 0.3 monolayers has a similar effect, leading to the formation of a hydrogen-bonded network of water and hydroxyl molecules at a ratio of 3:2. The partially dissociated layers are more stable than chemisorbed intact water with the maximum desorption temperatures up to 30 K higher. For higher oxygen coverage, up to 0.5 monolayers, water does not dissociate and an intact water species is observed above 160 K, which is characterized by an O 1s binding energy 0.6 eV higher than that of chemisorbed water and a high desorption temperature similar to the partially dissociated layer. The extra stabilization is most likely due to hydrogen bonds with atomic oxygen. (C) 2009 American Institute of Physics. [doi:10.1063/1.3266941]},
  author       = {Shavorskiy, A. and Eralp, T. and Ataman, Evren and Isvoranu, Cristina and Schnadt, Joachim and Andersen, Jesper N and Held, G.},
  issn         = {0021-9606},
  language     = {eng},
  number       = {21},
  publisher    = {American Institute of Physics},
  series       = {Journal of Chemical Physics},
  title        = {Dissociation of water on oxygen-covered Rh{111}},
  url          = {http://dx.doi.org/10.1063/1.3266941},
  volume       = {131},
  year         = {2009},
}