Composition based on cerium oxide and zirconium oxide and having high specific surface area and high oxygen storage capacity, and method for producing the same

摘要

A composition based on cerium oxide and on zirconium oxide and, optionally, on a yttrium, scandium or rare-earth metal oxide. The cerium/zirconium atomic proportion is at least 1. The compound exhibits a specific surface, after calcination for 6 hours at 900° C. of at least 35 m2/g and an oxygen storage capacity at 400° C. of at least 1.5 ml of O2/g. The composition is prepared by mixing, in a liquid medium, a cerium compound, a zirconium compound and, if appropriate, a yttrium, scandium or rare-earth metal compound; heating and calcining the precipitate obtained; and using a zirconium solution having an amount of base necessary to reach the equivalent point during an acid/base titration of the solution having a molar ratio of OH-/Zr=1.65. The composition thus obtained is used in the manufacture of multi-functional catalysts.