| abstract |
A catalyst used for producing, by catalytic gas phase oxidation of a C 3 -C 5 olefin or tertiary alcohol, the corresponding unsaturated aldehyde and unsaturated carboxylic acid, said catalyst characterized by comprising molybdenum, iron and bismuth and having a specific surface area in the range from 1 to 20m 2 /gr, a pore volume in the range from 0.1 to 1.0 cc/gr and a pore diameter distribution in which the pore diameters are collectively distributed in the range of each of from 1 to 10 microns and from 0.1 to 1 (exclusive) micron; and a process for preparing said catalyst by charging an unfired material powder into a centrifugal flow coating device to form particles having the average particle diameter of 2 to 10mm and then firing the particles. |