Decomposition of propan-2-ol on pure and doped rutile

Abstract

The decomposition of propan-2-ol on pure rutile and rutile doped with 0.1 mol% Cr₂O₃, Fe₂O₃, NiO, Nb₂O₅ or WO₃ has been studied between 438 and 519 K using a flow system. Rates of dehydration to propene and dehydrogenation to acetone were independent of propan-2-ol pressure between 2.9 × 10² and 4.4 × 10³ N m^–2, whereas rates of partial dehydration to di-isopropyl ether exhibited a low pressure dependence. Arrhenius parameters for the formation of all three products have been determined. Poisoning experiments indicate that dehydration proceeds by an acid-base mechanism, in which the effects of doping are “geometric” rather than “electronic”. Although doping influences dehydrogenation, the effects cannot be correlated with “geometric” or “electronic” factors.