摘要 |
A process for producing a composite metal oxide of an acidic metal oxide and a basic metal oxide, wherein the process comprises (a) providing an aqueous solution containing a colloidal particle of the acidic metal oxide and a salt of the basic metal, (b) adjusting the pH of the aqueous solution to a pH at which a part of the basic metal dissolves in the aqueous solution, the remaining of the basic metal precipitates as a hydroxide and has a positive zeta potential, and the colloidal particle of the acidic metal oxide is not dissolved and has a negative surface potential, and then maintaining this pH over a predetermined time to obtain a precursor of the composite metal oxide, and (c) drying and firing the precursor of the composite metal oxide obtained. |