Exchange reactions of propene on oxide catalysts investigated by microwave spectroscopy

Abstract

Microwave spectroscoy has been used to locate the position of the deuterium atoms in the products from the exchange of propene with either deuterium or deuterium oxide on a series of oxide catalysts. The evidence suggests that the main intermediates are carbonium ions on zirconia and untreated tin-antimony oxide, σ-allyl species on gallium oxide, propen-1-yl and to a lesser extent propen-2-yl and σ-allyl on γ-alumina, probably π-allyl on titania and magnesia, and both allyl species on used tin-antimony oxide. A very rapid double-bond shift reaction is believed to occur on magnesia at 200 K.