Process for preparing spherical shaped pelletized oxide catalysts comprising molybdenum and phosphorus

Claim 1

A process for preparing a spherical shape pelletized oxide catalytic composition having a high degree of reproducibility of catalytic activity for oxidizing an unsaturated aldehyde into an unsaturated carboxylic acid, said composition consisting essentially of ( 1) phosphorus, (2) molybdenum, (3) X in which X is at least one element selected from the group consisting of thallium and metals of Groups 1A and II of the periodic table and, optionally (4) Z in which Z is at least one element selected from the group consisting of silicon, chromium, aluminum, germanium, titanium, vanadium, tungsten, bismuth, niobium, boron, gallium, lead, tin, cobalt, palladium, arsenic, zirconium, antimony, iron, nickel, indium, copper, silver, manganese, lanthanum, neodymium, samarium and tellurium at an atomic ratio of P:Mo:X:Z of 0.1-8:12:0.01-10:0-12 and a surface area of 4 to 20m 2 /g and a pore volume of 0.08 to 0.5 ml/g, said catalyst composition being produced by tumbling granulation comprising the steps of: feeding the unpelletized, uncalcined catalytic composition into a tumbling granulator; granulating the composition at an elevated temperature while spraying a binder selected from the group consisting of water and ammonia water until granules of a predetermined size have formed; withdrawing the granules of said predetermined size; and calcining said granules.