| abstract |
The invention relates to a method for producing a catalyst-precursor containing vanadium, phosphorous and oxygen for the production of maleic acid anhydride by means of heterogeneous catalytic gas phase oxidation of a hydrocarbon having at least four hydrocarbon atoms by reacting vanadium pentoxide (I) in the presence of a primary or secondary, non-cyclic or cyclic, non-branched or branched, saturated alcohol having 3 - 6 carbon atoms (II) with one five or 3-valent phosphorous compound (III) by agitating in a temperature range of between 80 - 160 °C and subsequently filtration of the obtained suspension, wherein a filtration resistance of αH.θ of ≤50.1013 mPa.s/m2 is adjusted by (a) the manner in which the phosphorous compound (III) and the vanadium pentoxide (I) are brought together in the presence of the alcohol (II), (b) by the influence of an agitator power of between 0.01 0.6 W/kg suspension and/or (c) by the filtration in a temperature range of between 65 °C - 160 °C. The invention also relates to a catalyst-precursor obtained according to said method for producing a catalyst from the catalyst-precursor, a catalyst which can be obtained according to said method, in addition to a method for producing maleic acid anhydride on said catalyst. |