Surface diffusion and desorption of pentane isomers on Ru(001)

Journal Article · Thu Aug 23 00:00:00 EDT 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100380a047· OSTI ID:6380848

Arena, M V; Deckert, A A; Brand, J L; George, S M ^[1]

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1. Stanford Univ., CA (USA)

The surface diffusion and desorption of n-pentane, isopentane, cyclopentane, and neopentane were examined on Ru(001). These investigations used the techniques of laser-induced thermal desorption and temperature-programmed desorption. The surface diffusion activation energies varied from E{sub dif} = 3.0 {plus minus} 0.3 kcal/mol for neopentane to E{sub dif} = 4.4 {plus minus} 0.2 kcal/mol for n-pentane. The desorption activation energies ranged from E{sub des} = 10.7 {plus minus} 0.2 kcal/mol for neopentane to E{sub des} = 13.8 {plus minus} 0.9 kcal/mol for n-pentane. These results suggest that the pentane isomers have similar binding configurations and move on the Ru(001) surface in a concerted process. The magnitudes of the surface diffusion and desorption activation energies were observed to scale inversely with the degree of branching of the pentane isomer. The Wiener index, W(G), was employed to characterize the degree of branching. In addition, a simple physisorption model using a Lennard-Jones (6-12) pair potential was utilized to predict surface binding energies and configurations.

• OSTI ID: 6380848
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 94:17; 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
ACTIVATION ENERGY
ALKANES
BINDING ENERGY
DATA
DESORPTION
DIFFUSION
ELEMENTS
ENERGY
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
LENNARD-JONES POTENTIAL
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PENTANE
PLATINUM METALS
POTENTIALS
RUTHENIUM
SURFACE PROPERTIES
TRANSITION ELEMENTS