- Title
- Coverage-dependent molecular tilt of carbon monoxide chemisorbed on Pt{110}: a combined LEED and DFT structural analysis
- Creator
- Karakatsani, Sofia; Ge, Qingfeng; Gladys, Michael J.; Held, Geog; King, David A.
- Relation
- Surface Science Vol. 606, Issue 3-4, p. 383-393
- Publisher Link
- http://dx.doi.org/10.1016/j.susc.2011.10.025
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2012
- Description
- The adsorption of carbon monoxide on the Pt{110} surface at coverages of 0.5 ML and 1.0 ML was investigated using quantitative low-energy electron diffraction (LEED IV) and density-functional theory (DFT). At 0.5 ML CO lifts the reconstruction of the clean surface but does not form an ordered overlayer. At the saturation coverage, 1.0 ML, a well-ordered p(2 × 1) superstructure with glide line symmetry is formed. It was confirmed that the CO molecules adsorb on top of the Pt atoms in the top-most substrate layer with the molecular axes tilted by ± 22° with respect to the surface normal in alternating directions away from the close packed rows of Pt atoms. This is accompanied by significant lateral shifts of 0.55 Å away from the atop sites in the same direction as the tilt. The top-most substrate layer relaxes inwards by − 4% with respect to the bulk-terminated atom positions, while the consecutive layers only show minor relaxations. Despite the lack of long-range order in the 0.5 ML CO layer it was possible to determine key structural parameters by LEED IV using only the intensities of the integer-order spots. At this coverage CO also adsorbs on atop sites with the molecular axis closer to the surface normal (< 10°). The average substrate relaxations in each layer are similar for both coverages and consistent with DFT calculations performed for a variety of ordered structures with coverages of 1.0 ML and 0.5 ML.
- Subject
- carbon monoxide; platinum; density functional theory; low-energy electron diffraction
- Identifier
- http://hdl.handle.net/1959.13/1308092
- Identifier
- uon:21612
- Identifier
- ISSN:0039-6028
- Language
- eng
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