Effect of cesium modification of silica-supported vanadium oxide catalysts in butane oxidation

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1994.1245· OSTI ID:6879182

Owens, L; Kung, H H ^[1]

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1. Northwestern Univ., Evanston, IL (United States)

The effect of Cs modification in the selective oxidation of butane at 520[degrees]C was studied over SiO[sub 2]-supported catalysts containing about 6 or 0.6 wt% vanadium atoms using a butane/oxygen/helium mixture of 4/8/88. Dehydrogenation products (unsaturated C[sub 4]'s) and carbon oxides were the primary products. For the supported sample of high vanadium loading where a significant amount of vanadium existed as V[sub 2]O[sub 5] crystallites under reaction conditions, Cs modification significantly increased the selectivity for dehydrogenation and decreased the extent of reduction of the vanadium oxide crystallites in the reaction mixture, but had only small effects on the activation energy or rate of reaction. Unsupported V[sub 2]O[sub 5] catalysts modified by Cs at a Cs/V ratio of 0.023 also showed enhanced dehydrogenation selectivity, a lower degree of reduction at steady state, and a significantly different temperature-programmed reduction profile. Cs was found to be segregated on the surface of the crystallites. For the supported samples of low vanadium loading, Cs modification decreased the intensity of the Raman peak that was indicative of highly dispersed vanadia species and increased the activation energy of the reaction. These data were consistent with the picture that Cs modification enhanced the formation of vanadia on the support. 25 refs., 6 figs., 3 tabs.

• OSTI ID: 6879182
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 148:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

10 SYNTHETIC FUELS
100200 -- Synthetic Fuels-- Production-- (1990-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACTIVATION ENERGY
ALKALI METALS
ALKANES
BUTANE
CATALYSIS
CATALYST SUPPORTS
CATALYTIC EFFECTS
CESIUM
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DEHYDROGENATION
ELEMENTS
ENERGY
HETEROGENEOUS CATALYSIS
HYDROCARBONS
KINETICS
LASER SPECTROSCOPY
METALS
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
RAMAN SPECTROSCOPY
REACTION KINETICS
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
VANADIUM OXIDES