A STUDY OF MN-TI OXIDE POWDERS AND THEIR BEHAVIOR IN PROPANE OXIDATION CATALYSIS

Mn-Ti mixed oxides with composition Ti1-xMnxOy (x =0, 0.1, 0.2, 0.5; 0 .8, 0.9 and 1) have been prepared. A Mn-TiO2 monolayer type sample has also been prepared by impregnation, for comparison. Manganese is foun d to speed up the anatase-to-rutile phase transition,more clearly in t he impregnated sample, while titanium tends to slightly hinder the the rmodynamically reversible hausmannite-to-bixbyite phase transition upo n cooling; The catalytic activity of all samples in propene oxidation decreases by increasing the Ti content: Conversely, the catalytic acti vity in propane oxidation shows a maximum at intermediate composition.