| abstract |
A process for producing catalysts which are used for the vaporphase oxidation of olefinic hydrocarbons comprising impregnating a refractory carrier with a liquid oxytrihalide of vanadium selected from the group consisting of oxytrichloride and oxytribromide, removing the excess of said oxytrihalide of vanadium, hydrolyzing said oxytrihalide of vanadium and thereafter calcining the catalyst. |