The determination of surface polarity of bismuth-molybdenum oxidation catalysts by gas chromatography

Autor: M. Zdrazil, K. F. Scott
Rok vydání: 1980
Předmět:
Zdroj: Chromatographia. 13:85-92
ISSN: 1612-1112
0009-5893
DOI: 10.1007/bf02263059
Popis: The adsorption of aromatic and aliphatic hydrocarbons was investigated using gas chromatography on Bi2O3, MoO3 and mixed Bi−Mo oxidation catalysts. As a measure of polarity of a catalyst, the difference between the chemical potential of aromatic and aliphatic hydrocarbons at the same surface concentration was used. The chemical potentials were estimated from elution chromatographic data. The data for C6−C9 methylbenzenes and C6−C12 n-alkanes were obtained in the temperature range 60–300°C in nitrogen as a carrier gas. Using air as carrier gas, introduction of water pulses on a catalyst does not change the elution characteristics. The elution of alkenes, alkynes, dienes and carbonyl compounds was disturbed by reaction of these compounds on the surface. The polarity of catalysts decreased in the order mixed Bi−Mo catalysts, MoO3, Bi2O3. The polarities observed are compared with polarities of some other solids and liquids and the role of polarity of the surface in catalytic oxidation reactions is briefly discussed.
Databáze: OpenAIRE
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