Electronic effects in the coke deactivation of platinum-alumina catalysts
| Autor: | A. I. Solovykh, A. V. de Vekki, Yu. L. Kraev |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
chemistry.chemical_classification
General Chemical Engineering Inorganic chemistry Energy Engineering and Power Technology chemistry.chemical_element General Chemistry Coke Catalysis chemistry.chemical_compound Fuel Technology Hydrocarbon X-ray photoelectron spectroscopy chemistry Geochemistry and Petrology Desorption Pyridine Electronic effect Platinum |
| Zdroj: | Petroleum Chemistry. 48:210-218 |
| ISSN: | 1555-6239 0965-5441 |
| Popis: | By means of XPS, ESR, DTA, and pyridine flash desorption techniques; micropulse reactor studies; and quantum-chemical calculations, it was shown that, during the coking of platinum-alumina catalysts in hydrocarbon media, the electron density of the platinum atom increases up to the formation of Pt0, which is a deactivating factor from the viewpoint of the electronic effects. The stabilization of the activity of platinum-alumina catalysts consists in an increase in the effective positive charge on the platinum atom; this function is fulfilled by modifier elements. It was found that the platinum protection mechanism differs, depending on the nature of the modifying additive: certain elements function via another, additional mechanism of catalyst stabilization, the blocking action. The theoretical conclusions made in this study are corroborated by the results of testing a new, Pt-Sb-Re catalyst supported on Al2O3-Cl with predicted properties. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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