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AssigneeUbe Industries, Ltd.
InventorsSumio Umemura, Kyoji Ohdan, Fumihiko Sakai, Kenichi Suzuki, Yasuo Bando, Toshihiko Hogami, Masataka Fuginaga
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An improved catalyst suitable for use in the production of an unsaturated carboxylic acid by the catalytic vapor phase oxidation of an unsaturated aldehyde is provided. In this catalyst, a heat-resistant inorganic substance, such as alumina, silica-alumina and silicon carbide, having a particle diameter of 3 through 10 mm, an apparent porosity of 35 through 60%, a water absorption of 20 through 50%, an average pore diameter of not less than 40 microns, a specific surface area of not more than 2 m.sup.2 /g and a bulk specific gravity of 1.5 through 2.0 is used for supporting a composition containing molybdenum, phosphorus, vanadium and the alkali metals. The use of the above-mentioned carrier results in the advantages that the unsaturated carboxylic acid, such as methacrylic acid, can be selectively produced from the unsaturated aldehyde at a high yield and that the mechanical strength of the catalyst is remarkably improved.
In a catalyst containing molybdenum, phosphorus, vanadium and the alkali metals supported on a carrier which is used for the production of an unsaturated carboxylic acid by the catalytic vapor phase oxidation of an unsaturated aldehyde, the catalyst being prepared by admixing a composition containing the constituent elements of the catalyst with the carrier, whereby the composition is supported on pores of the carrier, followed by calcination;
A method for preparing a catalyst containing molybdenum, phosphorus, vanadium and alkali metal supported on a carrier which is used for the production of an unsaturated carboxylic acid by the catalytic vapor phase oxidiation of an unsaturated aldehyde, comprising the steps of:
Dependencies are inferred from the claim text.