COMPOSITION BASED ON ZIRCONIUM OXIDE AND AT LEAST ONE RARE EARTH OXIDE DIFFERENT FROM CERIUM, WITH SPECIFIC POROSITY, WAYS OF ITS PRODUCTION AND ITS APPLICATION IN CATALYSTS

摘要

1. A composition based on zirconium oxide and at least one rare earth oxide other than cerium, with a mass fraction of zirconium oxide of at least 50%, characterized in that after calcining at a temperature of 900 ° C for 4 hours, there are two sets of pores, the corresponding diameters of which are grouped for the first set near a value from 20 nm to 40 nm and for the second set about a value from 80 nm to 200 nm. 2. The composition according to claim 1, characterized in that the diameter of the first pore population is grouped around a value from 20 nm to 35 nm and more specifically from 20 nm to 30 nm, and the diameter of the second pore population is grouped around a value from 80 nm to 150 nm and more specifically from 90 nm to 110 nm. 3. A composition according to claim 1 or 2, characterized in that, after calcining at a temperature of 900 ° C for 4 hours, it has a total pore volume of at least 1.3 ml Hg / g, more specifically at least 1.5 ml Hg / g. 4. A composition according to claim 1 or 2, characterized in that, after calcining at 1100 ° C for 4 hours, a set of pores is observed in it, the diameter of which is grouped around a value from 30 nm to 70 nm. A composition according to claim 1 or 2, characterized in that, after calcining at 1100 ° C for 4 hours, it has a total pore volume of at least 0.9 ml Hg / g. 6. A composition according to claim 1 or 2, characterized in that it is based on the oxides of at least two rare earth elements other than cerium. A composition according to claim 1 or 2, characterized in that it has a content of rare earth oxide other than cerium from 10% to 30% .8. A composition according to claim 1 or 2, characterized in that the rare-earth element (s) other than cerium is (are) selected from the group consisting of