Influence of metal-support interactions on the reaction of methylcyclopentane over supported Pt catalysts

Journal Article · Thu Oct 01 04:00:00 EDT 1987 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(87)90301-0· OSTI ID:5269655

Anderson, J B.F.; Burch, R; Cairns, J A

Silica- and titania-supported Pt catalysts have been prepared and their reactivity in the hydrogenolysis of methylcyclopentane has been studied as a function of pretreatment. The Pt/silica catalysts are little affected by an increase in reduction temperature. When the Pt/titania catalysts are reduced at low temperature they have normal chemisorption properties. However, although the activity is similar to that of the Pt/silica catalysts, the product distributions are substantially different. In particular the Pt/titnia catalysts are more selective for the formation of n-hexane. After reduction at high temperature the Pt/titania catalysts no longer adsorb hydrogen and the catalytic activity is totally eliminated. When a reoxidation is performed at 298 K there is a partial recovery of the hydrogen chemisorption capacity and the turnover number of the Pt returns to its original value. However, in this intermediate state the catalyst produces even more n-hexane and less 2-methylpentane. From an analysis of the activation energy data it is concluded that the nature of the active centers is not affected by reduction and reoxidation treatments. Instead, the change in product distribution appears to parallel a variation in the relative proportions of the various types of active center present. The results are discussed in terms of various mechanisms for the methylcyclopentane reaction. It is concluded that the increased selectivity for the formation of n-hexane is consistent with a reaction at the metal-titania interface, possibly involving adsorption at a Pt-Ti/sup 3 +/ site. This site is believed to exist even in Pt/titania catalysts reduced at low temperatures.

• Research Organization: Univ. of Reading (England)
• OSTI ID: 5269655
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 107:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
ACTIVATION ENERGY
ALKANES
CATALYSIS
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISORPTION
CYCLOALKANES
ELEMENTS
ENERGY
HEXANE
HYDROCARBONS
HYDROGEN
HYDROGENATION
KINETICS
METALS
MINERALS
NONMETALS
ORGANIC COMPOUNDS
OXIDATION
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLATINUM
PLATINUM METALS
REACTION KINETICS
REDUCTION
SEPARATION PROCESSES
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS