Patent ID: 7795169

Claim:
A VPO catalyst of the general formula: [V 1 P a X b (Y) c O d ] e [Z] f , in which a=0.1-2.5 b=0-3.0, in particular 0.001-3.0 c=0.1-10 d=depends on the valency of the other elements e=5-100 (% by weight) f=95-0 (% by weight), in particular 95-5 with the provision that b and f are not simultaneously 0 X=Cr, Mo, W, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Zn or Nb Y=cyclic nitrogen compound, Z=SiO 2 , Al 2 O 3 , ZrO 2 or TiO 2 or their mixtures, manufactured in accordance with a method in which one carries out the following steps: a) converting V 2 O 5 and concentrated phosphoric acid in an organic medium under reflux conditions, b) separating off catalyst precursor that forms and optionally c) drying at 80 to 140° C., d) impregnating the optionally dried catalyst precursor with an aqueous or alcoholic solution of the metal X, with X having the significance quoted above, e) separating off excess solution, f) drying and calcining the impregnated material, and g) optionally forming the catalyst obtained.