Coverage dependence of molecular adsorption dynamics: Ethane on Pt(111)

Journal Article · Wed Mar 20 23:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100159a065· OSTI ID:5757759

Arumainayagam, C R; McMaster, M C; Madix, R J ^[1]

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1. Stanford Univ., CA (United States)

The dynamics of associative adsorption of ethane on Pt(111) as a function of ethane coverage was probed with supersonic molecular beam techniques. Adsorption probabilities were directly measured at coverages ranging from zero to monolayer saturation at incident translational energies between 10 and 40 kJ/mol and incident angles between 0{degree} and 60{degree} at a surface temperature of 95 K. In contrast to the predictions of the original Kisliuk model, at all incident translational energies and incident angles the adsorption probabilities increases with ethane coverage up to near monolayer coverage. This behavior can be fit quite adequately by a model that incorporates enhanced adsorption onto the covered surface compared to the clean surface, utilizing the experimental value of the adsorption probability onto the saturated monolayer. The angular dependence of the adsorption probability shows progressive deviation from normal energy scaling with increasing surface coverage, suggesting that the effective corrugation of the gas-surface interaction potential increases with adsorbate coverage.

• DOE Contract Number: FG03-86ER13468
• OSTI ID: 5757759
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:6; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ADSORPTION
ALKANES
AUGER ELECTRON SPECTROSCOPY
BEAMS
COHERENT SCATTERING
DATA
DIFFRACTION
ELECTRON DIFFRACTION
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY
ETHANE
EXPERIMENTAL DATA
FLUID FLOW
HYDROCARBONS
INCIDENCE ANGLE
INFORMATION
KINETIC ENERGY
MASS SPECTROSCOPY
MATHEMATICAL MODELS
METALS
MILLER INDICES
MOLECULAR BEAMS
NUMERICAL DATA
ORGANIC COMPOUNDS
PLATINUM
PLATINUM METALS
SCATTERING
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
SUPERSONIC FLOW
SURFACE PROPERTIES
SURFACES
TEMPERATURE RANGE
TEMPERATURE RANGE 0065-0273 K
THEORETICAL DATA
TRANSITION ELEMENTS