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- Blomberg, Sara, et al.
(författare)
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Structure of the Rh2O3(0001) surface
- 2012
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Ingår i: Surface Science. - : Elsevier BV. - 0039-6028. ; 606:17-18, s. 1416-1421
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the (0001) surface termination of Rh2O3 on a Rh(111) single crystal using a combination of high resolution core level spectroscopy, low energy electron diffraction, scanning tunneling microscopy and density functional theory. By exposing the Rh(111) to atomic oxygen we are able to grow Rh2O3 layers exposing the (0001) surface. The experiments support the theoretical predictions stating that the surface is terminated with an O-Rh-O trilayer yielding a RhO2 termination instead of a bulk Rh2O3 termination. The structural details as found by the DFT calculations are presented and reasons for the previously observed strong differences in catalytic activity between the structurally similar RhO2 surface oxide, and the Rh2O3(0001) surface are discussed. (C) 2012 Elsevier B.V. All rights reserved.
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| 2. |
- Martin, Natalia, et al.
(författare)
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Toward a Silver-Alumina Model System for NOx Reduction Catalysis
- 2014
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 118:42, s. 24556-24561
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Tidskriftsartikel (refereegranskat)abstract
- The growth and morphology of Ag deposited on NiAl(110) and on oxidized NiAl(110) have been investigated by a combination of scanning tunneling microscopy (STM) and high-resolution core-level spectroscopy (HRCLS). While the STM measurements reveal complete wetting and a bilayer growth on clean NiAl(110), Ag nanoparticles with a minimum size of 5 nm were obtained on the oxidized NiAl(110). The difference in Ag growth mode on clean and oxidized NiAl(110) is supported by Ag 3d HRCLS. The binding energy for Ag on clean NiAl(110) is the same as for bulk Ag, while the Ag 3d peak for particles on oxidized NiAl(110) shifts toward the bulk binding energy with increasing size. The adsorption properties at 100 K of CO and NO on oxidized NiAl(110) and on Ag particles on oxidized NiAl(110) were also investigated by probing the C 1s and N 1s core levels. In the case of oxidized NiAl(110), neither CO nor NO adsorbs. In the case of Ag particles on oxidized NiAl(110), CO does not adsorb, but a component at 397 eV is observed in the N 1s level after NO exposures. This component is tentatively assigned to silver nitride, suggesting NO dissociation in the presence of Ag particles on oxidized NiAl(110).
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