COMPOSITION OF CERIUM OXIDE, ZIRCONIUM DIOXIDE AND ALUMINUM OXIDE WITH INCREASED THERMAL STABILITY

摘要

1. A method of producing a calcined mixed oxide containing Al, Ce, and Zr oxides, comprising the following steps: (a) providing an aqueous suspension containing cerium and zirconium hydroxides, (b) bringing cerium and zirconium hydroxides into contact with an alumina precursor to obtain an aqueous suspension of solid particles, (c) separating the solid particles from the aqueous suspension and drying to obtain a solid composition, (d) firing the solid composition from step (c) at a temperature of from 450 ° C to 1200 ° C for at least 1 hour to get calcined mixed oxide. 2. The method of claim 1, wherein drying in step (c) comprises: i) filtering and air drying; and / or ii) spray drying. 3. The method according to any one of paragraphs. 1 or 2, wherein the aqueous suspension in step (a) further comprises one or more rare earth metal hydroxides other than cerium. 4. The method according to any one of paragraphs. 1 or 2, in which the aqueous suspension contains cerium based on cerium oxide (CeO) in the range of 5% to 90% by weight based on the total oxide content (TO) in the calcined mixed oxide. 5. The method according to any one of paragraphs. 1 or 2, wherein the calcined mixed oxide in step (d) contains: - cerium from 5 to 90% by mass, - aluminum from 20 to 80% by mass, - zirconium from 5 to 80% by mass, and optionally rare earths metals (RE) from 0 to 12% by weight, where the contents of cerium, zirconium and rare earth metals (RE) are calculated based on CeO, ZrO, AlO or REO, respectively. 6. The method according to any one of paragraphs. 1 or 2, including the use of a surfactant. 7. The method of claim 6, wherein the surfactant is an organic surfactant.