N/sub 2/ adsorption method for measuring certain acid-base sites on alumina
Surface acidity of gamma alumina is complex and highly dependent on the pretreatment drying conditions. An interpretation of some of the changes occurring on predrying has been provided by a model of the alumina surface based on random dehydroxylation to produce both OH groups and Al-oxide ion pairs of differing nearest neighbor configurations. Certain of these Al-oxide ion pairs with strained linkages have been termed alpha sites. They form very reactive centers and can have particular significance for industrial processes using alumina-based catalysts running above 400/sup 0/C. Recently the authors have found that sites closely associated, if not actual alpha sites, will strongly adsorb molecular N/sub 2/ just below room temperature. This note reports results found with three different commercial aluminas and relates the observations to similar adsorptions of CO and adsorbed CO/sub 2/ characterized by an IR band near 2360 cm/sup -1/. In addition, the results of coking reactions conducted on these aluminas are reported. 15 references.
- Research Organization:
- Amoco Oil Co., Naperville, IL
- OSTI ID:
- 5366420
- Journal Information:
- J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 105:2; ISSN JCTLA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ADSORPTION
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONIZATION
CATALYST SUPPORTS
CATALYSTS
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMATOGRAPHY
COKING
COMPARATIVE EVALUATIONS
DECOMPOSITION
DRYING
ELEMENTS
GAS CHROMATOGRAPHY
INFRARED SPECTRA
MEASURING METHODS
NITROGEN
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
SEPARATION PROCESSES
SORPTION
SPECTRA
SURFACE PROPERTIES