초록 ▼

A zirconium- and cerium-based mixed oxide having good thermal stability and oxidation-reduction performance, in particular, is provided. The mixed oxide which comprises zirconium and cerium is characterized in (1) that cubic phase purity of a zirconia- and ceria-based solid solution is not less than

A zirconium- and cerium-based mixed oxide having good thermal stability and oxidation-reduction performance, in particular, is provided. The mixed oxide which comprises zirconium and cerium is characterized in (1) that cubic phase purity of a zirconia- and ceria-based solid solution is not less than 95% by volume of the crystal phase thereof and (2) that the cubic phase purity is not less than 75% by volume even after two repetitions of the step of subjecting the mixed oxide to heat treatment at 1,000.degree. C. and then cooling the same to room temperature. A method of producing the mixed oxide is also provided which comprises admixing basic zirconium sulfate with a cerium ion-containing solution and then adding a base to the resulting mixed solution to thereby causing formation of a precipitate.

대표청구항 ▼

[ What is claimed is:] [1.]1. A zirconium- and cerium-based mixed oxide comprising zirconium and cerium, characterized in (1) that cubic phase purity of a zirconia- and ceria-based solid solution is not less than 95% by volume of the crystal phase thereof and (2) that the cubic phase purity is not l

[ What is claimed is:] [1.]1. A zirconium- and cerium-based mixed oxide comprising zirconium and cerium, characterized in (1) that cubic phase purity of a zirconia- and ceria-based solid solution is not less than 95% by volume of the crystal phase thereof and (2) that the cubic phase purity is not less than 75% by volume even after at least two repetitions of the step of subjecting the mixed oxide to heat treatment at 1,000.degree. C. and then cooling the same to room temperature.