Development of surface acidity in water-oxidized alumina films. Ethylene adsorption as a function of pretreatment temperature

Journal Article · Wed Mar 02 23:00:00 EST 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100060a034· OSTI ID:7069730

Rhodin, T N; Merrill, R P; O'Hagan, P J; Woronick, S C ^[1]; Shinn, N D ^[2]; Woolery, G L; Chester, A W ^[3]

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1. Cornell Univ., Ithaca, NY (United States)
2. Sandia National Lab., Albuquerque, NM (United States)
3. Mobile Research and Development Corporation, Paulsboro, NJ (United States)

The structure and surface acidity of thin water-oxidized alumina films on Al(110) have been studied as a function of film treatment temperature and ethylene adsorption using X-ray photoelectron spectroscopy. The OH content of the oxides decreases monotonically with temperature while the crystallinity increases uniformly to form a polycrystalline [gamma]-alumina at 500[degree]C. Ethylene adsorbed on the oxides identifies the presence of acid sites with a maximum spectral intensity for alumina films pretreated between 350 and 400[degree]C. An interpretation is proposed in terms of a molecular orbital adsorbate-surface model based on the core level and valence level photoemission data to explain how chemisorbed molecular ethylene adsorbate may form from a [pi]-complex adduct on the acid sites. The results are consistent with the formation of a [sup +]C[sub 2]H[sub 5] carbenium ion. 31 refs., 10 figs., 3 tabs.

• DOE Contract Number: AC04-94AL85000; AC02-76CH00016
• OSTI ID: 7069730
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:9; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201* -- Chemical & Physicochemical Properties
ADSORPTION
ALKENES
ALUMINIUM
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CATALYSTS
CHALCOGENIDES
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
DATA
ELECTRON SPECTROSCOPY
ELEMENTS
ETHYLENE
EXPERIMENTAL DATA
FILMS
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
SORPTION
SPECTROSCOPY
THEORETICAL DATA
WATER
X-RAY SPECTROSCOPY