Thermal Stability of Single-Crystalline IrO2(110) Layers : Spectroscopic and Adsorption Studies
(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.
(Less)
- author
- organization
- publishing date
- 2020
- 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}}, }