Activity and selectivity of bifunctional platinum catalysts in hydrocarbon reactions

Journal Article · Thu Dec 31 23:00:00 EST 1981 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(82)90077-X· OSTI ID:5509629

Christoffel, E G; Paal, Z

Conversions of a number of C/sub 6/-C/sub 8/-alkanes, naphthenes, and aromatics on bifunctional platinum/carrier catalysts, on Pt-black, and on the acidic carriers of the bifunctional catalysts are investigated in the temperature range 300 to 500/sup 0/C and at hydrogen partial pressures of 0 to 45 bars in a continuously operated fixed-bed reactor and in microcatalytic pulse reactors. Three activity and selectivity levels of the platinum in bifunctional Pt/acidic carrier catalysts may be broadly recognized: (1) temperatures below 350/sup 0/C where mainly platinum-catalyzed reactions contribute to the measured product distributions, (2) a temperature region around 400/sup 0/C where platinum drastically changes its activity and selectivity in hydrogenolysis and isomerization reactions due to removable carbonaceous deposits, and (3) a region above about 400/sup 0/C where due to irreversible carbiding platinum only displays (de)hydrogenation activity. The product distributions from conversions of the model compounds on irreversibly carbided Pt/carrier catalysts are mainly governed by acid-catalyzed interconversions through nonclassical carbonium ion intermediates. 14 figures, 3 tables.

• Research Organization: Ruhr-Universitaet, Bochum, West Germany
• OSTI ID: 5509629
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 73:1; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

090110 -- Hydrocarbon Fuels-- Properties-- (1979-1989)
10 SYNTHETIC FUELS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALKANES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
AROMATICS
CARBIDES
CARBON COMPOUNDS
CARBONACEOUS MATERIALS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CRACKING
CYCLOALKANES
DATA
DEACTIVATION
DECOMPOSITION
DEPOSITION
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
EXPERIMENTAL DATA
FLUIDS
GASES
HELIUM
HEXANE
HIGH TEMPERATURE
HYDROCARBONS
HYDROCRACKING
HYDROGEN
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
ISOMERIZATION
KINETICS
MATERIALS
MEDIUM PRESSURE
METALS
MINERALS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PACKED BED
PLATINUM
PLATINUM CARBIDES
PLATINUM COMPOUNDS
PLATINUM METALS
PRESSURE DEPENDENCE
PULSES
PYROLYSIS
RARE GASES
REACTION INTERMEDIATES
REACTION KINETICS
REACTIVITY
SPECIFICITY
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
YIELDS
ZEOLITES