Cerium oxide and zirconium oxide based composite rare earth oxide with favorable ageing resistance and high reduction activity and preparation method of cerium oxide and zirconium oxide based composite rare earth oxide

Provided is a method for preparing cerium oxide and zirconium oxide based composite rare earth oxide. The method comprises: (1) preparing a zircon salt solution; (2) prepare an activating agent solution by mixing urea and sulfuric acid or sulfate; (3) heating the zircon salt solution at a room temperature, dropwise adding the activating agent solution slowly, controlling the temperature rise speed to make the temperature raised to 60 degrees centigrade after the addition of the activating agent solution is finished, continuing to raising the temperature to 90 to 95 degrees centigrade, and keeping the temperature for 20-100min to form a basic zirconium sulfate composite salt precursor solution; (4) preparing soluble cerate and rare earth metal salt, adding the soluble cerate and the rare earth metal salt into the basic zirconium sulfate composite salt precursor solution, and performing precipitation by using a soluble hydroxide or ammonia solution; and (5) filtering and cleaning precipitates, and then, calcini