Surface photochemistry: products retained on Pt(111) during photolysis of adsorbed CH/sub 3/Br

Journal Article · Wed Jun 22 04:00:00 EDT 1988 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00221a074· OSTI ID:5992680

Zhou, Y; Feng, W M; Henderson, M A; Roop, B; White, J M

The photochemistry of molecules at the gas-solid interface has been successfully investigated in a number of laboratories, but very little work has shown photochemistry on clean metal surfaces. Previous work from this research group showed that the photolysis of methyl halides (CH/sub 3/Br, CH/sub 3/Cl) adsorbed on Pt(111) lead to a detectable amount of methane (290 K), but no other hydrocarbons, in TPD. For CH/sub 3/Br, Br desorbed as atoms between 720 and 950 K. Significantly, these two methyl halides show no thermal chemistry on Pt(111). The results suggest that, as in the gas phase, CH/sub 3/X (X = Br, Cl) absorbs UV light and forms an electronically excited state that is repulsive and, with significant probability, cleaves the C-X bond even though other relaxation paths exist. In this communication the authors identify, using vibrational spectroscopy, the adsorbed species formed during UV irradiation of CH/sub 3/Br on Pt(111). By comparison with measurements on CH/sub 3/I, which thermally decomposes to CH/sub 3/(a) and I(a), the authors identify adsorbed methyl as the hydrocarbon fragment formed and retained during the photolysis.

• Research Organization: Univ. of Texas, Austin (USA)
• OSTI ID: 5992680
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 110:13; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
ABSORPTION SPECTROSCOPY
ADSORPTION
BROMINATED ALIPHATIC HYDROCARBONS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
GASES
HALOGENATED ALIPHATIC HYDROCARBONS
INFORMATION
INTERFACES
METALS
METHYL BROMIDE
NUMERICAL DATA
ORGANIC BROMINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOLYSIS
PLATINUM
PLATINUM METALS
SOLIDS
SORPTION
SPECTROSCOPY
SURFACE PROPERTIES
SURFACES
TRANSITION ELEMENTS