Comparison between zeolite [beta] and [gamma]-Al[sub 2]O[sub 3] supported Pt for reforming reactions

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1103· OSTI ID:6374902

Smirniotis, P G; Ruckenstein, E ^[1]

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1. State Univ. of New York, Buffalo (United States)

The performance of zeolite [beta] supported platinum as a bifunctional catalyst for the reforming of n-hexane, methylcyclopentane, and cyclohexane, typical representatives of reforming feeds, has been examined under low severity conditions. A comparison under the same conditions with [gamma]-Al[sub 2]O[sub 3] supported Pt was carried out. Both catalysts were impregnated with 0.5 wt % Pt. It is found that [beta]-zeolite exhibits skeletal isomerization reactions to a higher extent than alumina, producing molecules with much higher octane number than the feed molecules. Bimolecular alkylation reactions that take place in the zeolite pores have as a result the formation of products with a carbon number larger than that of the feed molecule. The enlargement of the cyclic ring of methylcyclopentane leads at suitable temperatures to aromatics, a reaction of great importance for reforming. This behavior is a result of the relatively large acidity of the zeolite and of its pore structure that favors the proximity among different molecules increasing the probability for reaction. In contrast, Pt/Al[sub 2]O[sub 3] stimulates dehydrogenation-hydrogenation and to a smaller extent skeletal isomerization. This [beta]-zeolite is deactivated more easily than alumina due to the coke build up on the acidic sites. The characterization of the catalysts has been carried out using XRD, NH[sub 3]-TPD, SEM, FTIR, BET, TEM, and H[sub 2]-chemisorption. 50 refs., 9 figs., 7 tabs.

• OSTI ID: 6374902
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 140:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
ABSORPTION SPECTROSCOPY
ALKANES
ALKYLATION
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
AROMATICS
CATALYSIS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CATALYTIC REFORMING
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISORPTION
COHERENT SCATTERING
COKE
CYCLOALKANES
CYCLOHEXANE
DEHYDROGENATION
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
HETEROGENEOUS CATALYSIS
HEXANE
HYDROCARBONS
HYDROGEN
HYDROGENATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
ISOMERIZATION
MATERIALS
MICROSCOPY
MINERALS
NONMETALS
OCTANE
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM COMPOUNDS
REFORMER PROCESSES
SCANNING ELECTRON MICROSCOPY
SCATTERING
SEPARATION PROCESSES
SILICATE MINERALS
SORPTION
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ZEOLITES