| abstract |
Catalyst containing a vanadium-phosphorus-oxide mixture for the oxidation of hydrocarbons, especially n-butane, to maleic anhydride. The catalyst has a V / P ratio of 1: to 1: 1.3 and the pore volume of the pores, with a radius of 100 to 1000 A, is at least 30% of the total pore volume of the pores with a radius of less than 10 The catalyst is prepared in an organic solvent, a phosphorus-containing compound being introduced, the vanadium-containing compound being continuously added to the reaction mixture and the water formed being removed directly from the reaction mixture. |