Dissociation of water on oxygen-covered Rh(111)

Journal Article · Mon Dec 07 00:00:00 EST 2009 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3266941· OSTI ID:21559812

Shavorskiy, A; Eralp, T; Held, G ^[1]; Ataman, E; Isvoranu, C; Schnadt, J; Andersen, J N ^[2]

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1. Department of Chemistry, The University of Reading, Whiteknights, Reading RG6 6AD (United Kingdom)
2. Department of Synchrotron Radiation Research, Institute of Physics, Lund University, P.O. Box 118, S-221 00 Lund (Sweden)

The adsorption of water and coadsorption with oxygen on Rh(111) under ultrahigh vacuum conditions was studied using synchrotron-based photoemission and photoabsorption spectroscopy. Water adsorbs intact on the clean surface at temperatures below 154 K. Irradiation with x-rays, however, induces fast dissociation and the formation of a mixed OH+H{sub 2}O layer indicating that the partially dissociated layer is thermodynamically more stable. Coadsorption of water and oxygen at a coverage below 0.3 monolayers has a similar effect, leading to the formation of a hydrogen-bonded network of water and hydroxyl molecules at a ratio of 3:2. The partially dissociated layers are more stable than chemisorbed intact water with the maximum desorption temperatures up to 30 K higher. For higher oxygen coverage, up to 0.5 monolayers, water does not dissociate and an intact water species is observed above 160 K, which is characterized by an O 1s binding energy 0.6 eV higher than that of chemisorbed water and a high desorption temperature similar to the partially dissociated layer. The extra stabilization is most likely due to hydrogen bonds with atomic oxygen.

• OSTI ID: 21559812
• Journal Information: Journal of Chemical Physics, Vol. 131, Issue 21; Other Information: DOI: 10.1063/1.3266941; (c) 2009 American Institute of Physics; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ADSORPTION
BINDING ENERGY
DESORPTION
DISSOCIATION
HYDROGEN
HYDROXIDES
IRRADIATION
LAYERS
OXYGEN
PHOTOELECTRON SPECTROSCOPY
PHOTOEMISSION
RHODIUM 111
STABILIZATION
SYNCHROTRONS
WATER
X RADIATION
ACCELERATORS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CYCLIC ACCELERATORS
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELEMENTS
EMISSION
ENERGY
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
IONIZING RADIATIONS
ISOTOPES
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
RADIATIONS
RADIOISOTOPES
RHODIUM ISOTOPES
SECONDARY EMISSION
SECONDS LIVING RADIOISOTOPES
SORPTION
SPECTROSCOPY