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Thermal Stability of Single-Crystalline IrO2(110) Layers : Spectroscopic and Adsorption Studies

Abb, Marcel J.S. ; Weber, Tim ; Langsdorf, Daniel ; Koller, Volkmar ; Gericke, Sabrina M. LU ; Pfaff, Sebastian LU ; Busch, Michael ; Zetterberg, Johan LU orcid ; Preobrajenski, Alexei LU and Grönbeck, Henrik , et al. (2020) In Journal of Physical Chemistry C 124(28). p.15324-15336
Abstract

The interaction of ultrathin single-crystalline IrO2(110) films with the gas phase proceeds via the coordinatively unsaturated sites (cus), in particular Ircus, the undercoordinated oxygen species on-top O (Oot) that are coordinated to Ircus, and bridging O (Obr). With the combination of different experimental techniques, such as thermal desorption spectroscopy, scanning tunneling microscopy (STM), high-resolution core-level spectroscopy (HRCLS), infrared spectroscopy, and first-principles studies employing density functional theory calculations, we are able to elucidate surface properties of single-crystalline IrO2(110). We provide spectroscopic fingerprints of the active surface sites of IrO2(110). The freshly prepared IrO2(110)... (More)

The interaction of ultrathin single-crystalline IrO2(110) films with the gas phase proceeds via the coordinatively unsaturated sites (cus), in particular Ircus, the undercoordinated oxygen species on-top O (Oot) that are coordinated to Ircus, and bridging O (Obr). With the combination of different experimental techniques, such as thermal desorption spectroscopy, scanning tunneling microscopy (STM), high-resolution core-level spectroscopy (HRCLS), infrared spectroscopy, and first-principles studies employing density functional theory calculations, we are able to elucidate surface properties of single-crystalline IrO2(110). We provide spectroscopic fingerprints of the active surface sites of IrO2(110). The freshly prepared IrO2(110) surface is virtually inactive toward gas-phase molecules. The IrO2(110) surface needs to be activated by annealing to 500-600 K under ultrahigh vacuum (UHV) conditions. In the activation step, Ircus sites are liberated from on-top oxygen (Oot) and monoatomic Ir metal islands are formed on the surface, leading to the formation of a bifunctional model catalyst. Vacant Ircus sites of IrO2(110) allow for strong interaction and accommodation of molecules from the gas phase. For instance, CO can adsorb atop on Ircus and water forms a strongly bound water layer on the activated IrO2(110) surface. Single-crystalline IrO2(110) is thermally not very stable although chemically stable. Chemical reduction of IrO2(110) by extensive CO exposure at 473 K is not observed, which is in contrast to the prototypical RuO2(110) system.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physical Chemistry C
volume
124
issue
28
pages
13 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:85089282286
ISSN
1932-7447
DOI
10.1021/acs.jpcc.0c04373
project
Combined techniques for studies of catalysis
language
English
LU publication?
yes
id
220f54c9-8ec8-4790-89e6-9913c423ba71
date added to LUP
2020-08-18 12:04:36
date last changed
2023-11-20 09:25:46
@article{220f54c9-8ec8-4790-89e6-9913c423ba71,
  abstract     = {{<p>The interaction of ultrathin single-crystalline IrO2(110) films with the gas phase proceeds via the coordinatively unsaturated sites (cus), in particular Ircus, the undercoordinated oxygen species on-top O (Oot) that are coordinated to Ircus, and bridging O (Obr). With the combination of different experimental techniques, such as thermal desorption spectroscopy, scanning tunneling microscopy (STM), high-resolution core-level spectroscopy (HRCLS), infrared spectroscopy, and first-principles studies employing density functional theory calculations, we are able to elucidate surface properties of single-crystalline IrO2(110). We provide spectroscopic fingerprints of the active surface sites of IrO2(110). The freshly prepared IrO2(110) surface is virtually inactive toward gas-phase molecules. The IrO2(110) surface needs to be activated by annealing to 500-600 K under ultrahigh vacuum (UHV) conditions. In the activation step, Ircus sites are liberated from on-top oxygen (Oot) and monoatomic Ir metal islands are formed on the surface, leading to the formation of a bifunctional model catalyst. Vacant Ircus sites of IrO2(110) allow for strong interaction and accommodation of molecules from the gas phase. For instance, CO can adsorb atop on Ircus and water forms a strongly bound water layer on the activated IrO2(110) surface. Single-crystalline IrO2(110) is thermally not very stable although chemically stable. Chemical reduction of IrO2(110) by extensive CO exposure at 473 K is not observed, which is in contrast to the prototypical RuO2(110) system. </p>}},
  author       = {{Abb, Marcel J.S. and Weber, Tim and Langsdorf, Daniel and Koller, Volkmar and Gericke, Sabrina M. and Pfaff, Sebastian and Busch, Michael and Zetterberg, Johan and Preobrajenski, Alexei and Grönbeck, Henrik and Lundgren, Edvin and Over, Herbert}},
  issn         = {{1932-7447}},
  language     = {{eng}},
  number       = {{28}},
  pages        = {{15324--15336}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{Journal of Physical Chemistry C}},
  title        = {{Thermal Stability of Single-Crystalline IrO<sub>2</sub>(110) Layers : Spectroscopic and Adsorption Studies}},
  url          = {{http://dx.doi.org/10.1021/acs.jpcc.0c04373}},
  doi          = {{10.1021/acs.jpcc.0c04373}},
  volume       = {{124}},
  year         = {{2020}},
}