PROCESS FOR PRODUCING UNSATURATED ALDEHYDE AND/OR UNSATURATED CARBOXYLIC ACID

PROBLEM TO BE SOLVED: To subject at least one compound selected from propylene, isobutylene, and tertiary butyl alcohol to gas phase catalytic oxidation with good conversion to produce the corresponding unsaturated aldehyde and/or unsaturated carboxylic acid in a good yield. SOLUTION: More than one kind of catalysts composed of predetermined composite oxides which differ in the kind and/or the content of constituting metallic elements from one another can be obtained by independently drying an aqueous solution or aqueous slurry containing the catalyst components, thereafter firing the dried product in the atmosphere of a molecular oxygen-containing gas, and successively heat treating the fired product in the presence of a reducing substance, and the obtained more than one kind of catalysts are filled in a reaction tube so as for the catalytic activity to become higher directed from the inlet for raw material gases to the outlet, and the above oxidation reaction is carried out by supplying the raw material gasses to the above reaction tube. COPYRIGHT: (C)2009,JPO&INPIT