Why does the activity of Pd/Al2O3 catalysts in the reaction of methane oxidation depend on the dispersion of palladium phase?

• Autorzy: Machocki A. , Stasińska B. , Gac W.
• Języki publikacji: EN

Abstrakty

EN

The characterization of Pd/Al2O3 catalysts with varied dispersio of palladium phase, prepared with a chlorine-free precursor, with similar palladium loading and on the same support has been performed in order to identify the factors responsible for the variation of their activity in the oxidation of methane. The higher dispersion of the palladium phase decreases the temperatures necessary to achieve desired methane conversions. The rate (turnover number) of the reaction is higher on small crystallites up to 350°C, at higher temperatures the opposite relation is observed. Such dependences can result from the changes in the number of Pd-PdO active sites, and the different activity of the single active site may be attributed to the interaction between palladium phase crystallites and Al2O3 support. This interaction causes different redox properties of the small and large palladium phase crystallites, i.e.: (i) easier oxidation of palladium and stronger bonding of oxygen in small palladium oxide crystallites, (ii) easier donation of lattice oxide ions from the support to small palladium phase crystallites and (iii) their stabilization in a more oxidized state.

Słowa kluczowe

EN

oxidation of methane; flameless combustion; Pd/Al2O3 catalysts; palladium dispersion; temperature-programmed methods; oxygen isotopic exchange

PL

utlenianie metanu; spalanie bezpłomieniowe; katalizatory Pd/Al2O3; metody temperaturowo programowane

• Wydawca: West Pomeranian University of Technology. Publishing House
• Czasopismo: Polish Journal of Chemical Technology
• Rocznik: 2006
• Tom: Vol. 8, nr 2
• Strony: 93--96
• Opis fizyczny: Bibliogr. 14 poz., rys., tab.

Twórcy

autor

Machocki A.

autor

Stasińska B.

autor

Gac W.

• University of Maria Curie-Skłodowska, Faculty of Chemistry, Department of Chemical Technology, PL Maria Curie-Skłodowska 3, 20-031 Lublin,

Bibliografia

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