OXIDE SOLID SOLUTION PARTICLE AND ITS PRODUCTION

PROBLEM TO BE SOLVED: To obtain an oxide solid solution particle high in oxygen storage ability, small in the average particle diameter of a crystallite and large in specific surface are by heating a precipitate obtained by adding a surfactant and an alkaline material into an aq. solution, in which Ce and Zr and dissolved. SOLUTION: An aq. solution is prepared by mixing cerium (III) nitrate and zirconium nitrate so as to have the molar ratio of Ce/Zr=5/5 and is neutralized to form a precipitate by dropping an ammoniacal liquor while stirring. Successively a hydrogen peroxide solution containing hydrogen peroxide of 1/2mol of Ce ion contained in the mixed solution and an aq. solution containing 10% alkyl benzene sulfonic acid by weight per an oxide to be obtained are added and mixed while stirring. The resultant slurry is sprayed in an atmosphere of 400 deg.C introduced air temp. and 250 deg.C discharged air temp. to be dried by a spray drying method and coexisting ammonium nitrate is vaporized or decomposed to prepare a powder containing the oxide solid solution. The degree of the solid solution is 100%, the average particle diameter is 10nm and the specific surface area is 45m /g.