An examination of the acid sites in SAPO-5

Journal Article · Sun Sep 01 04:00:00 EDT 1991 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(91)90342-2· OSTI ID:5637190

Biaglow, A I; Adamo, A T; Kokotailo, G T; Gorte, R J ^[1]

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1. Univ. of Pennsylvania, Philadelphia (United States)

The authors have examined a series of SAPO-5 materials using temperature-programmed desorption and thermogravimetric analysis (TPD-TGA) of isopropylamine, n-propylamine, ammonia, propene, and 2-propanol and compared the results to those for AlPO-5. For isopropylamine and n-propylamine, desorption of propene and ammonia was observed from well-defined features in the TPD-TGA curves, features which were not observed on AlPO-5. These desorption features appear to be due to simple Broensted-acid sites, and the concentration of sites determined by both amines was the same. For low Si concentrations, there appears to be one acid site per framework Si. The differences between AlPO-5 and SAPO-5 materials could also be observed with propene, which oligomerized at 300 K in SAPO-5 but not in AlPO-5. While differences were observed between AlPO-5 and the SAPO-5s for TPD-TGA of ammonia and 2-propanol, desorption from sites present in AlPO-5 were difficult to distinguish from the stronger sites present in the SAPO-5s. The results suggest that adsorption of simple amines may be very useful for characterization of acid sites in silica aluminophosphate molecular sieves.

• OSTI ID: 5637190
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 131:1; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ADSORBENTS
ADSORPTION
ALCOHOLS
ALKENES
ALUMINIUM COMPOUNDS
ALUMINIUM PHOSPHATES
AMINES
AMMONIA
BROENSTED ACIDS
CHALCOGENIDES
CHEMICAL ANALYSIS
CONTROL
DESORPTION
GRAVIMETRIC ANALYSIS
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INORGANIC ACIDS
MINERALS
MOLECULAR SIEVES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
PHOSPHATES
PHOSPHORUS COMPOUNDS
PROPANOLS
PROPYLENE
QUANTITATIVE CHEMICAL ANALYSIS
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
SURFACE PROPERTIES
TEMPERATURE CONTROL
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS