Patent ID: 8247075

Claim:
A method for producing a modified perovskite-type composite oxide, comprising the steps of: (A1) preparing a slurry comprising a perovskite-type composite oxide and a hydrophilic organic solvent; (A2) adding tetraalkoxysilane to the slurry, and carrying out a hydrolysis reaction in the presence of a catalyst to precipitate silica on the particle surface of the perovskite-type composite oxide, so as to obtain a perovskite-type composite oxide coated with the hydrolyzed silica; (A3) drying at 60° C. to 120° C. and then performing a heat treatment at 800° C. to 1200° C. over three hours on the perovskite-type composite oxide coated with the hydrolyzed silica, so as to obtain a perovskite-type composite oxide that is primarily coated with silica, which has pH 8.0 or less that is obtained by contact with water; and (A4) allowing the perovskite-type composite oxide that is primarily coated with silica to come into contact with a coupling agent.