Theoretical studies of chemisorption and surface reactions on nickel and silicon: Progress report, June 15, 1987-June 14, 1988
The research is part of a theoretical program on the structure of molecules adsorbed on solid surfaces and dissociative chemisorption with emphasis on transition metal substrates and electronic materials. An embedding theory for treating chemisorption on metals is being developed and applied to the reaction of hydrocarbon fragments and hydrogen coadsorbed on nickel and the chemisorption of water on nickel. The main emphasis of the work is on the energetics of adsorption as a function of surface site. The first phase of the nickel-hydrocarbon fragment project concerning the reaction CH + H = CH/sub 2/ on Ni(111) was completed this year. Detailed energetics and structural information are obtained for the CH, CH/sub 2/ and H species at the most stable sites on Ni(III) and for intermediate steps along the reaction pathway. The reaction producing CH/sub 2/ is exothermic, however, an energy barrier exists for the approach of H toward CH. Both CH and CH/sub 2/ are most strongly bound at three-fold adsorption sites on the (111) surface. Frequencies of H-, HC- and H/sub 2/C-surface vibrations and CH vibrations are calculated. Studies of the adsorption of C/sub 6/H/sub 6/ on Ni(111) show an upward tilt of the hydrogens (7.5/sup 0/ out of the carbon plane) occurs in the minimum energy geometry. The results are now being analyzed to determine the surface dipole and effect on benzene adsorption on the work function. Work on the recombination reaction of hydrogen on nickel was also started during this period. Studies of the fragmentation of CH/sub 4/ to produce adsorbed CH/sub 3/ + H on nickel are underway.
- Research Organization:
- State Univ. of New York, Stony Brook (USA)
- DOE Contract Number:
- FG02-84ER45100
- OSTI ID:
- 5485725
- Report Number(s):
- DOE/ER/45100-4; ON: DE88005820
- Country of Publication:
- United States
- Language:
- English
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Theoretical studies of chemisorption and surface reactions on nickel and silicon
Theoretical studies of chemisorption and surface reactions on nickel and silicon: Progress report for period June 15, 1988--June 14, 1989
Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BENZENE
ADSORPTION
HYDROCARBONS
CHEMISORPTION
HYDROGEN
NICKEL
SORPTIVE PROPERTIES
SILICON
DECOMPOSITION
DISSOCIATION
PROGRESS REPORT
RADICALS
RECOMBINATION
SURFACES
AROMATICS
CHEMICAL REACTIONS
DOCUMENT TYPES
ELEMENTS
METALS
NONMETALS
ORGANIC COMPOUNDS
SEMIMETALS
SEPARATION PROCESSES
SORPTION
SURFACE PROPERTIES
TRANSITION ELEMENTS
360104* - Metals & Alloys- Physical Properties
400201 - Chemical & Physicochemical Properties