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Oxygen interaction with the Pd(112) surface: From chemisorption to bulk oxide formation

Vlad, Alina; Stierle, Andreas; Westerström, Rasmus LU ; Blomberg, Sara LU ; Mikkelsen, Anders LU and Lundgren, Edvin LU (2012) In Physical Review B (Condensed Matter and Materials Physics) 86(3).
Abstract
We investigated the interaction of oxygen with the Pd(112) surface from ultrahigh vacuum up to 5 mbars oxygen partial pressure in a temperature range from 523 to 673 K. We combined in situ surface x-ray diffraction with scanning tunneling microscopy, high-resolution core-level spectroscopy, and low-energy electron diffraction. A structural model of the clean Pd(112) is proposed based on the x-ray-diffraction data. The morphology of the Pd(112) surface is strongly influenced by the oxidation conditions: at 673 K, upon exposure to oxygen at pressures from 2 x 10(-8) to 5 x 10(-5) mbar, the (112) surface undergoes a massive rearrangement and (113)and (335)-type facets are formed. Further increase of the O-2 partial pressure leads to a new... (More)
We investigated the interaction of oxygen with the Pd(112) surface from ultrahigh vacuum up to 5 mbars oxygen partial pressure in a temperature range from 523 to 673 K. We combined in situ surface x-ray diffraction with scanning tunneling microscopy, high-resolution core-level spectroscopy, and low-energy electron diffraction. A structural model of the clean Pd(112) is proposed based on the x-ray-diffraction data. The morphology of the Pd(112) surface is strongly influenced by the oxidation conditions: at 673 K, upon exposure to oxygen at pressures from 2 x 10(-8) to 5 x 10(-5) mbar, the (112) surface undergoes a massive rearrangement and (113)and (335)-type facets are formed. Further increase of the O-2 partial pressure leads to a new rearrangement into (111)- and (113)-type facets. This is in contrast to the previous observation that (112) facets are stabilized on MgO supported Pd nanoparticles under oxygen exposure [P. Nolte, A. Stierle, N. Kasper, N. Y. Jin-Phillipp, N. Jeutter, and H. Dosch, Nano Lett. 11, 4697 (2011)]. Based on the core-level spectroscopy and scanning tunneling microscopy measurements, the transition from chemisorbed oxygen to surface oxide formation was identified to take place at pressures of 10(-3) mbar O-2 and 623 K. Kinetic barriers for the formation of the PdO bulk oxide are observed to be reduced compared to low index Pd surfaces. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B (Condensed Matter and Materials Physics)
volume
86
issue
3
publisher
American Physical Society
external identifiers
  • wos:000306089200018
  • scopus:84863681658
ISSN
1098-0121
DOI
10.1103/PhysRevB.86.035407
language
English
LU publication?
yes
id
ef3d9ff9-f11f-4d95-a241-70f7a97f2920 (old id 2995012)
date added to LUP
2012-08-21 15:10:10
date last changed
2017-07-30 03:57:13
@article{ef3d9ff9-f11f-4d95-a241-70f7a97f2920,
  abstract     = {We investigated the interaction of oxygen with the Pd(112) surface from ultrahigh vacuum up to 5 mbars oxygen partial pressure in a temperature range from 523 to 673 K. We combined in situ surface x-ray diffraction with scanning tunneling microscopy, high-resolution core-level spectroscopy, and low-energy electron diffraction. A structural model of the clean Pd(112) is proposed based on the x-ray-diffraction data. The morphology of the Pd(112) surface is strongly influenced by the oxidation conditions: at 673 K, upon exposure to oxygen at pressures from 2 x 10(-8) to 5 x 10(-5) mbar, the (112) surface undergoes a massive rearrangement and (113)and (335)-type facets are formed. Further increase of the O-2 partial pressure leads to a new rearrangement into (111)- and (113)-type facets. This is in contrast to the previous observation that (112) facets are stabilized on MgO supported Pd nanoparticles under oxygen exposure [P. Nolte, A. Stierle, N. Kasper, N. Y. Jin-Phillipp, N. Jeutter, and H. Dosch, Nano Lett. 11, 4697 (2011)]. Based on the core-level spectroscopy and scanning tunneling microscopy measurements, the transition from chemisorbed oxygen to surface oxide formation was identified to take place at pressures of 10(-3) mbar O-2 and 623 K. Kinetic barriers for the formation of the PdO bulk oxide are observed to be reduced compared to low index Pd surfaces.},
  articleno    = {035407},
  author       = {Vlad, Alina and Stierle, Andreas and Westerström, Rasmus and Blomberg, Sara and Mikkelsen, Anders and Lundgren, Edvin},
  issn         = {1098-0121},
  language     = {eng},
  number       = {3},
  publisher    = {American Physical Society},
  series       = {Physical Review B (Condensed Matter and Materials Physics)},
  title        = {Oxygen interaction with the Pd(112) surface: From chemisorption to bulk oxide formation},
  url          = {http://dx.doi.org/10.1103/PhysRevB.86.035407},
  volume       = {86},
  year         = {2012},
}