Investigation of methane oxidation onPt/Al2O3 catalysts under transient reaction conditions

Autor: Burch, R., Loader, P.K.
Zdroj: Applied Catalysis A: General; February 1995, Vol. 122 Issue: 2 p169-190, 22p
Abstrakt: The oxidation of methane on alumina-supported platinum catalysts has been investigated for various gas mixtures as a function of the state of oxidation or reduction of the platinum surface. It has been shown that the activity for methane oxidation goes through a sharp maximum a few seconds after the introduction of the reactants to either a pre-reduced or a pre-oxidised catalyst. The results are inter-preted in terms of a Langmuir-Hinshelwood mechanism in which the optimum rate of reaction corresponds to a platinum surface partially covered byboth oxygen- and carbon-containing species. The position of the maximum in activity is very reproducible for pre-reduced catalysts but varies in an imprecise manner for pre-oxidised catalysts. These effects are thought to be related to morphological changes in the reduced and subsequently re-oxidised small platinum particles. It appears that even after re-oxidation at 300°C these platinum particles have a strong ‘memory’ of previous reduction treatments.
Databáze: Supplemental Index
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