Abstract
The orthovanadates of the alkaline and alkaline earth metals and the un-modified alkaline earth oxides have been compared with vanadium pentoxide as catalysts for the oxidative dehydrogenation of ethane and propane. The orthovanadates do not contain the V=O species known to cause deeper oxidation; the presence of alkaline and alkaline earth metals also reduces the acidity of the vanadium pentoxide component. It was found that pure vanadium pentoxide gave substantial combustion. The orthovanadates gave an increase in selectivity towards olefin production in the order Ba≤Sr≤Ca≤Mg and this was coupled with an increase in activity in the same order. The unmodified alkaline earth oxides also exhibited some activity and selectivity, the selectivity increasing in the same order; however, the activity increased from BaO to MgO. For the orthovanadate series, there was a shift in the V-O infra-red absorption band to higher frequencies. Selective oxidation over the orthovanadates thus seems to depend mainly on the strength of the V-O bond.
Original language | English |
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Pages (from-to) | 505-514 |
Number of pages | 10 |
Journal | Studies in Surface Science and Catalysis |
Volume | 55 |
Issue number | C |
DOIs | |
Publication status | Published - 1 Jan 1990 |
Externally published | Yes |