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Kinetics of the reduction of the Rh(111) surface oxide: Linking spectroscopy and atomic-scale information

Klikovits, J ; Schmid, M ; Gustafson, Johan LU ; Mikkelsen, Anders LU ; Resta, Andrea LU ; Lundgren, Edvin LU ; Andersen, Jesper N LU and Varga, P (2006) In The Journal of Physical Chemistry Part B 110(20). p.9966-9975
Abstract
The reduction of the surface oxide on Rh(111) by H-2 was observed in situ by scanning tunneling microscopy (STM) and high-resolution core level spectroscopy (HRCLS). At room temperature, H-2 does not adsorb on the oxide, only in reduced areas. Reduction starts in very few sites, almost exclusively in stepped areas. One can also initiate the reduction process by deliberately creating defects with the STM tip allowing us to examine the reduction kinetics in detail. Depending on the size of the reduced area and the hydrogen pressure, two growth regimes were found. At low H2 pressures or small reduced areas, the reduction rate is limited by hydrogen adsorption on the reduced area. For large reduced areas, the reduction rate is limited by the... (More)
The reduction of the surface oxide on Rh(111) by H-2 was observed in situ by scanning tunneling microscopy (STM) and high-resolution core level spectroscopy (HRCLS). At room temperature, H-2 does not adsorb on the oxide, only in reduced areas. Reduction starts in very few sites, almost exclusively in stepped areas. One can also initiate the reduction process by deliberately creating defects with the STM tip allowing us to examine the reduction kinetics in detail. Depending on the size of the reduced area and the hydrogen pressure, two growth regimes were found. At low H2 pressures or small reduced areas, the reduction rate is limited by hydrogen adsorption on the reduced area. For large reduced areas, the reduction rate is limited by the processes at the border of the reduced area. Since a near-random distribution of the reduction nuclei was found and the reduction process at defects starts at a random time, one can use Johnson-Mehl-Avrami- Kolmogoroff (JMAK) theory to describe the process of reduction. The microscopic data from STM agree well with spatially averaged data from HRCLS measurements. (Less)
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type
Contribution to journal
publication status
published
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in
The Journal of Physical Chemistry Part B
volume
110
issue
20
pages
9966 - 9975
publisher
The American Chemical Society (ACS)
external identifiers
  • wos:000237626400038
  • scopus:33745742535
ISSN
1520-5207
DOI
10.1021/jp0611875
language
English
LU publication?
yes
id
5da0386a-78f4-49d0-9a39-6ed7ea7f9a2a (old id 408583)
date added to LUP
2016-04-01 16:16:35
date last changed
2021-04-13 04:16:40
@article{5da0386a-78f4-49d0-9a39-6ed7ea7f9a2a,
  abstract     = {The reduction of the surface oxide on Rh(111) by H-2 was observed in situ by scanning tunneling microscopy (STM) and high-resolution core level spectroscopy (HRCLS). At room temperature, H-2 does not adsorb on the oxide, only in reduced areas. Reduction starts in very few sites, almost exclusively in stepped areas. One can also initiate the reduction process by deliberately creating defects with the STM tip allowing us to examine the reduction kinetics in detail. Depending on the size of the reduced area and the hydrogen pressure, two growth regimes were found. At low H2 pressures or small reduced areas, the reduction rate is limited by hydrogen adsorption on the reduced area. For large reduced areas, the reduction rate is limited by the processes at the border of the reduced area. Since a near-random distribution of the reduction nuclei was found and the reduction process at defects starts at a random time, one can use Johnson-Mehl-Avrami- Kolmogoroff (JMAK) theory to describe the process of reduction. The microscopic data from STM agree well with spatially averaged data from HRCLS measurements.},
  author       = {Klikovits, J and Schmid, M and Gustafson, Johan and Mikkelsen, Anders and Resta, Andrea and Lundgren, Edvin and Andersen, Jesper N and Varga, P},
  issn         = {1520-5207},
  language     = {eng},
  number       = {20},
  pages        = {9966--9975},
  publisher    = {The American Chemical Society (ACS)},
  series       = {The Journal of Physical Chemistry Part B},
  title        = {Kinetics of the reduction of the Rh(111) surface oxide: Linking spectroscopy and atomic-scale information},
  url          = {http://dx.doi.org/10.1021/jp0611875},
  doi          = {10.1021/jp0611875},
  volume       = {110},
  year         = {2006},
}