| abstract |
A process is described for preparing an activatednporous phosphorus/vanadium oxide catalyst adapted for thencatalytic oxidation of a hydrocarbon to produce ancarboxylic acid anhydride. The catalyst comprises anshaped body having a volume of at least about 0.02 cc, anphosphorus content of between about 1.05 and about 1.20, anB.E.T. surface area of at least about 15 m 2 /g, an averagenvanadium oxidation state of between about 4.06 and aboutn4.3, a total pore volume of at least about 0.15 cc/g, annormalized apparent shaped body density of between aboutn1.0 and about 2.0 g/cc, and a crush strength of at leastnabout 4 pounds [1.81kg]. At least about 20% of the porenvolume of the catalyst is constituted of pores having andiameter between about 0.1 and about 3.3 µm, and at leastnabout 40% of the pore volume is constituted of poresnhaving a diameter of less than about 0.1 µm. The catalystnis prepared by mixing a particulate phosphorus/vanadiumnoxide precursor with a pore modification agent to producena modified catalyst precursor composition, forming thenmodified precursor composition into a predetermined shape,nand removing the pore modification agent substantially atna temperature below 300°C, preferably using air as anstripping gas. |