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Reduction behavior of oxidized Pd(100) and Pd75Ag25(100) surfaces using CO

Fernandes, V. R.; Gustafson, Johan LU ; Svenum, I. -H.; Farstad, M. H.; Walle, L. E.; Blomberg, Sara LU ; Lundgren, Edvin LU and Borg, A. (2014) In Surface Science 621. p.31-39
Abstract
The reduction of the (A root 5x root 5)R27 degrees surface oxide on Pd(100) and Pd75Ag25(100) surfaces by CO has been investigated by high-resolution X-ray photoelectron spectroscopy in combination with kinetic analysis using the Avrami-Erofeev theory. For both surfaces we observed faster reduction with increasing temperature. Kinetic analysis indicates that the reduction process is phase boundary controlled for Pd(100) in the temperature range investigated, from 30 degrees C to 120 degrees C On Pd75Ag25(100) the surface oxide reduction is significantly slower compared to Pd(100). Also in this case, a phase boundary controlled reduction of the surface oxide is observed at temperatures of 120 C and above, while at T <= 70 degrees C the... (More)
The reduction of the (A root 5x root 5)R27 degrees surface oxide on Pd(100) and Pd75Ag25(100) surfaces by CO has been investigated by high-resolution X-ray photoelectron spectroscopy in combination with kinetic analysis using the Avrami-Erofeev theory. For both surfaces we observed faster reduction with increasing temperature. Kinetic analysis indicates that the reduction process is phase boundary controlled for Pd(100) in the temperature range investigated, from 30 degrees C to 120 degrees C On Pd75Ag25(100) the surface oxide reduction is significantly slower compared to Pd(100). Also in this case, a phase boundary controlled reduction of the surface oxide is observed at temperatures of 120 C and above, while at T <= 70 degrees C the reduction is found to be diffusion limited. Density functional theory calculations show that the presence of silver in the outermost surface layer significantly increases the CO diffusion barriers on the reduced areas, supporting a diffusion limited reduction process for Pd75Ag25(100) at lower temperatures. (C) 2013 Elsevier B.V. All rights reserved. (Less)
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author
organization
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Contribution to journal
publication status
published
subject
keywords
Surface oxide reduction, Pd75Ag25(100), Pd(100), Photoelectron, spectroscopy, Avrami kinetics, Density functional theory
in
Surface Science
volume
621
pages
31 - 39
publisher
Elsevier
external identifiers
  • wos:000330909300005
  • scopus:84891749647
ISSN
0039-6028
DOI
10.1016/j.susc.2013.10.018
language
English
LU publication?
yes
id
c8093725-d572-4862-92ee-8ea153594d33 (old id 4376321)
date added to LUP
2014-04-14 13:33:13
date last changed
2017-07-30 04:09:28
@article{c8093725-d572-4862-92ee-8ea153594d33,
  abstract     = {The reduction of the (A root 5x root 5)R27 degrees surface oxide on Pd(100) and Pd75Ag25(100) surfaces by CO has been investigated by high-resolution X-ray photoelectron spectroscopy in combination with kinetic analysis using the Avrami-Erofeev theory. For both surfaces we observed faster reduction with increasing temperature. Kinetic analysis indicates that the reduction process is phase boundary controlled for Pd(100) in the temperature range investigated, from 30 degrees C to 120 degrees C On Pd75Ag25(100) the surface oxide reduction is significantly slower compared to Pd(100). Also in this case, a phase boundary controlled reduction of the surface oxide is observed at temperatures of 120 C and above, while at T &lt;= 70 degrees C the reduction is found to be diffusion limited. Density functional theory calculations show that the presence of silver in the outermost surface layer significantly increases the CO diffusion barriers on the reduced areas, supporting a diffusion limited reduction process for Pd75Ag25(100) at lower temperatures. (C) 2013 Elsevier B.V. All rights reserved.},
  author       = {Fernandes, V. R. and Gustafson, Johan and Svenum, I. -H. and Farstad, M. H. and Walle, L. E. and Blomberg, Sara and Lundgren, Edvin and Borg, A.},
  issn         = {0039-6028},
  keyword      = {Surface oxide reduction,Pd75Ag25(100),Pd(100),Photoelectron,spectroscopy,Avrami kinetics,Density functional theory},
  language     = {eng},
  pages        = {31--39},
  publisher    = {Elsevier},
  series       = {Surface Science},
  title        = {Reduction behavior of oxidized Pd(100) and Pd75Ag25(100) surfaces using CO},
  url          = {http://dx.doi.org/10.1016/j.susc.2013.10.018},
  volume       = {621},
  year         = {2014},
}