Monsanto Company

Huntsman Specialty Chemicals Corporation

William J Andrews

Jerry R Ebner

Timothy R Felthouse

A phosphorus vanadium oxide catalyst for the oxidation of a C.sub.4 hydrocarbon. The catalyst comprises a shaped body having a volume, or a fixed bed comprising shaped bodies having an average volume, of at least about 0.02 cc, and contains a promoter selected from among Bi, Sb, Ge, Ti, Zr, La, Ce, Ni, Zn, U, Sn, Si or mixtures thereof. The promoter is present in a proportion that enables the catalyst to have a developed surface area of at least about 28 m.sup.2 /g, and to exhibit a weight/area productivity of at least about 3.5 mg maleic anhydride/m.sup.2 -hr and/or a weight/weight productivity of at least about 100 g maleic anhydride/kg.cat.-hr. when contacted with a gas containing 2.4% by volume n-butane in air, at a gas flow volume to catalyst weight ratio of 2180 cc/g-min., under a pressure of 1.055.times.10.sup.2 -kPa-G, and at a temperature sufficient to maintain a hydrocarbon conversion of 85 mole percent. Methods for the preparation of the catalyst include activation by ANST.

Catalysis for the production of maleic anhydride containing

An activated porous phosphorus/vanadium oxide catalyst adapted for the catalytic oxidation of a hydrocarbon to produce a carboxylic acid anhydride. The catalyst comprises shaped bodies having a B.E.T. surface area of at least about 15 m.sup.2 /g, an average vanadium oxidation state of between about 4.0 and about 4.5, a total pore volume of at least about 0.15 cc/g, a normalized apparent shaped body density of between about 1.25 and about 2.0 g/cc, and a crush strength of at least about 4 pounds. At least about 5% of the pore volume of the catalyst is constituted of pores having a diameter of at least about 0.8 microns, and at least about 4% of the pore volume is constituted of pores having a diameter of at least about 10 microns. The catalyst is prepared by mixing a particulate phosphorus/vanadium oxide precursor with a pore modification agent to produce a modified catalyst precursor composition, forming the modified precursor composition into a predetermined shape, and removing the pore modification agent substantially at a temperature below 300.degree. C.

Phosphorous/vanadium oxide catalyst and process of preparation thereof

Vanadium/phosphorus mixed oxide catalysts comprising vanadyl pyrophosphate, optionally containing a promoter component, are transformed from vanadium/phosphorus mixed oxide catalyst precursors comprising vanadyl hydrogen phosphate, optionally containing a promoter component, by subjecting the catalyst precursors to elevated temperatures in three stages--(a) an initial heat-up stage in an atmosphere selected from the group consisting of air, steam, an inert gas, and mixtures thereof, (b) a rapid heat-up stage at a programmed heat-up rate in a molecular oxygen/steam-containing atmosphere, and (c) a maintenance/finishing stage, first in a molecular oxygen/-steam-containing atmosphere, and thereafter in a nonoxidizing, steam-containing atmosphere. Such catalysts are useful for the production of maleic anhydride via the partial oxidation of nonaromatic hydrocarbons, particularly n-butane, in the vapor phase with molecular oxygen or a molecular oxygen-containing gas.

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Hazelwood, MO, United States of America

William J Andrews