Detection of chemisorbed methyl and methylene groups: Surface chemistry of methyl iodide on Pt(111)

Journal Article · Thu Aug 08 04:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100169a042· OSTI ID:7273987

Zaera, F; Hoffmann, H ^[1]

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1. Univ. of California, Riverside (United States)

The thermal chemistry of methyl iodide on Pt(111) surfaces was studied by using thermal programmed desorption (TPD), X-ray photoelectron (XPS), and reflection-absorption (RAIRS) spectroscopies. Spectra obtained at low temperatures for both normal and fully deuterated methyl iodide indicate that chemisorption is molecular and that the adsorption geometry changes with coverage, starting with a tilted configuration after small doses and switching to a structure where the C-I bond is perpendicular to the surface above half-saturation. The only reaction that can be thermally activated at low coverages is a C-I bond breaking step, which is then followed by total dehydrogenation and by hydrogen desorption. At higher coverages, however, an appreciable amount of methane also desorbs, and both methyl and methylene groups form on the surface.

• OSTI ID: 7273987
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:16; 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
ABSORPTION
CHEMICAL REACTIONS
CHEMISORPTION
DATA
DEUTERIUM COMPOUNDS
ELECTRON SPECTROSCOPY
ELEMENTS
EXPERIMENTAL DATA
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
IODINATED ALIPHATIC HYDROCARBONS
METALS
METHYL IODIDE
MILLER INDICES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PLATINUM
PLATINUM METALS
REFLECTION
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
SURFACE PROPERTIES
THERMAL ANALYSIS
TRANSITION ELEMENTS
X-RAY SPECTROSCOPY