Published 1988
| Version v1
Journal article
Carbon monoxide adsorbed on cesium-covered Ru(001) surfaces. Exchange reactions and angular distribution of desorption
Description
Three pathways of isotope exchange of CO adsorbed, i.e. (i) 12C16O(a) + 13C18O(a) → 13C16O(g) + 12C18O(g), (ii) 18O(a) + 12C16O(a) → 16O(a)+12C18O(g), and (iii) 12C(a) + 13C18O(a) → 13C(a) + 12C18O(g), were studied over cesium-covered Ru(001) surfaces by means of thermal desorption. The fraction of the exchange products in desorbed carbon monoxide increases sharply around ΘCs = 0.6 ΘCs,max, where ΘCs,max is the monolayer coverage of Cs. The angular distribution of the CO desorption varies as (cosΘ)3-4 above ΘCs = 0.6 ΘCs,max, where Θ is the desorption angle. The correlation of the isotope exchange to the sharp angular distribution is discussed with a dissociation-recombination mechanism. (orig.)
Abstract (German)
Auf Ru(001)-Flaechen wurden bei unterschiedlich dichter Belegung mit Caesium an adsorbiertem CO drei Isotopenaustausch-Prozesse, naemlich: (i) 12C16O(a) + 13C18O(a) → 13C16O(g) + 12C18O(g), (ii) 18O(a) + 12C16O(a) → 16O(a) + 12C18O(g), (iii) 12C(a) + 13C18O(a) → 13C(a) + 12C18O(g), mit Hilfe der thermischen Desorption studiert. Der Anteil an Austauschprodukten im desorbierten Kohlenmonoxid steigt in der Naehe von ΘCs = 0,6 ΘCs,max steil an, wobei ΘCs,max eine Cs-Monolage bedeutet. Die Winkelverteilung des desorbierenden CO laesst sich oberhalb von ΘCs = 0,6 ΘCs,max durch (cos Θ)3-4 beschreiben, wobei Θ der Desorptionswinkel ist. Die Korrelation des Isotopenaustausches mit der scharfen Winkelverteilung wird aufgrund eines Dissoziations-Rekombinations-Mechanismus diskutiert. (orig.)Additional details
Publishing Information
- Journal Title
- Zeitschrift fuer Physikalische Chemie. Neue Folge
- Journal Volume
- 158
- Journal Issue
- pt.2
- Series
- Z. Phys. Chem., Neue Folge.
- Journal Page Range
- 175-188
- ISSN
- 0044-3336
- CODEN
- ZPCFA
INIS
- Country of Publication
- Germany
- Country of Input or Organization
- Germany
- INIS RN
- 22015117
- Subject category
- S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
- Descriptors DEI
- ADSORPTION; ANGULAR DISTRIBUTION; CARBON MONOXIDE; CARBON 12; CARBON 13; CESIUM; DESORPTION; ISOTOPIC EXCHANGE; LAYERS; OXIDATION; OXYGEN 16; OXYGEN 18; POTENTIAL ENERGY; RUTHENIUM; SPECTRA; SURFACES
- Descriptors DEC
- ALKALI METALS; CARBON COMPOUNDS; CARBON ISOTOPES; CARBON OXIDES; CHALCOGENIDES; CHEMICAL REACTIONS; DISTRIBUTION; ELEMENTS; ENERGY; EVEN-EVEN NUCLEI; EVEN-ODD NUCLEI; ISOTOPES; LIGHT NUCLEI; METALS; NUCLEI; OXIDES; OXYGEN COMPOUNDS; OXYGEN ISOTOPES; PLATINUM METALS; STABLE ISOTOPES; TRANSITION ELEMENTS