| abstract |
An oxidation catalyst formed from V₂0₅ and TiO₂ of rutile structure is obtained by a process which comprises the following stages:n a) preparation of a solution of Ti(IV) by dissolution (partial hydrolysis) of TiCl₄ in an aqueous solution at a final pH below 1.0, b) preparation of a solution of V(IV) by heating, in order to dissolve it, solid V₂0₅ suspended in an aqueous oxalic acid solution, c) precipitation of metatitanic acid from the Ti(IV) solution at a pH not higher than 1.3, d) precipitation of vanadium oxide from the said V(IV) solution in the presence of the metatitanic acid obtained in (c), and e) separation of the precipitate, drying and calcination thereof at elevated temperature. n This gives a catalyst formed from V₂0₅ and TiO₂ of rutile structure, which has a specific surface area of the order of 10-60 m²/g, is highly active, selective and stable under conditions of catalytic oxidation, especially under the conditions of the oxidation of o-xylene to phthalic anhydride. |