Catalyst and process for the production of maleic anhydride

The invention relates to a vanadium-, phosphorus- and oxygen-containing catalyst that is used for producing maleic anhydride by heterogeneous catalytic gas phase oxidation of a hydrocarbon carrying at least four carbon atoms in which the ratio of phosphorus/vanadium is 0.9 to 1.5. Said catalyst comprises particles with an average diameter of at least 2 mm and the composition has a x-ray powder diffraction pattern, obtained by irradiation with CuK alpha radiation ( lambda = 1.54 10 m), that produces in the 2 theta range of 10 DEG to 70 DEG a signal/noise ratio of vanadium- and phosphorus-containing phase. The invention further relates to a method for producing such a catalyst and to a method for producing maleic anhydride on such a catalyst.