Calorimetric study of vanadium pentoxide catalysts used in the reaction of ethane oxidative dehydrogenation
- Institut de Recherches sur la Catalyse, Villeurbanne (France); and others
Vanadium pentoxide catalysts have been studied in the partial oxidation reaction of ethane in the 723-843 K temperature range. The relationship between the acid-base properties and the catalytic behavior was investigated. The number and character of acidic sites of V{sub 2}O{sub 5} catalysts were determined by studying the adsorption of a basic molecule using microcalorimetry. The reducibility level and the evolution of the surface state, as well as the heat evolved, were studied by using a pulse method with pure ethane only. The reaction of ethane oxidative dehydrogenation was studied by a continuous flow method and the activation energies for the formation of C{sub 2}H{sub 4} and CO were calculated. The selectivity of the catalyst was interpreted in connection with the acid-base properties. The strong sites were observed to decrease rapidly with time on stream, although the catalysts were still active. Temperature-programmed reduction of V{sub 2}O{sub 5} using a TG-DSC coupling was also investigated with hydrogen, ethylene, or ethane as reducers. The different heats of reduction are given. It was observed that C{sub 2}H{sub 4} is a much more efficient reducing agent than H{sub 2} and C{sub 2}H{sub 6}. Following each reduction, reoxidation studies by oxygen were performed in the same equipment showing clearly different step in the reoxidation process. 20 refs., 8 figs., 1 tab.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 255259
- Journal Information:
- Journal of Physical Chemistry, Vol. 96, Issue 5; Other Information: PBD: 5 Mar 1992
- Country of Publication:
- United States
- Language:
- English
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