Acid catalysis by dealuminated zeolite Y. 2. The roles of aluminum
Hexane cracking activity was determined for a series of dealuminated zeolites which were prepared both by treatment with SiCl/sub 4/ and by reaction with steam. Over a range of Si/Al ratios from 4.7 to 255 the cracking activity increased in a linear manner with respect to the number of lattice Al ions per unit cell. Thus, a constant turnover frequency is obtained, which is taken as evidence that the acid strength does not vary over this range of Si/Al ratios. By contrast, a zeolite prepared by deamination of NH/sub 4/-Y was very much less active than expected on the basis of the number of protonic sites. The acidity of the protons in this material is clearly less than in the dealuminated zeolite. These results support a model of strong Broensted acidity in which a structural aluminum atom has no next-nearest aluminum neighbors in a common 4-ring of the zeolite.
- Research Organization:
- Texas A and M Univ., College Station
- OSTI ID:
- 5037101
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 90:20; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
10 SYNTHETIC FUELS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
ALUMINIUM
CATALYSIS
CATALYTIC CRACKING
CATALYTIC EFFECTS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CRACKING
DATA
DECOMPOSITION
ELEMENTS
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
HEXANE
HYDROCARBONS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
METALS
MINERALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PYROLYSIS
SILICON CHLORIDES
SILICON COMPOUNDS
STEAM
THERMOCHEMICAL PROCESSES
ZEOLITES