초록 ▼

The present invention provides a zirconia-based mixed oxide which, together with improving the heat resistance of specific surface area at a high temperature (1000° C. for 3 hours), has a ceria reduction rate of 80% or more, or in other words, improves the heat resistance of specific surface ar

The present invention provides a zirconia-based mixed oxide which, together with improving the heat resistance of specific surface area at a high temperature (1000° C. for 3 hours), has a ceria reduction rate of 80% or more, or in other words, improves the heat resistance of specific surface area and the reduction rate of ceria. The zirconia-based mixed oxide has zirconia for the main component thereof and contains 5% or more of ceria and 1 to 30% of a rare earth metal oxide other than ceria, wherein the specific surface area after heat treating for 3 hours at 1000° C. is 50 m2/g or more, the reduction rate of the ceria contained in the mixed oxide is 80% or more, and preferably the specific surface area after heat treating for 3 hours at 1100° C. is 20 m2/g or more.

대표청구항 ▼

What is claimed is: 1. A zirconia-based mixed oxide comprising 1) zirconia for the main component, 2) 5 wt % or more of ceria and 3) 1 to 30 wt % of a rare earth metal oxide other than ceria, wherein the specific surface area after heat treating for 3 hours at 1000° C. is 50 m2/g or more, and

What is claimed is: 1. A zirconia-based mixed oxide comprising 1) zirconia for the main component, 2) 5 wt % or more of ceria and 3) 1 to 30 wt % of a rare earth metal oxide other than ceria, wherein the specific surface area after heat treating for 3 hours at 1000° C. is 50 m2/g or more, and a ceria reduction rate in the mixed oxide is 80% or more. 2. The zirconia-based mixed oxide according to claim 1, wherein the specific surface area after heat treating for 3 hours at 1100° C. is 20 m2/g or more. 3. The zirconia-based mixed oxide according to claim 1 or 2, wherein the rare earth metal oxide other than ceria includes at least one of an oxide of lanthanum and an oxide of neodymium.