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AssigneeRhodia Chimie
InventorsMaryline Aubert, Thierry Birchem, Gilbert Blanchard
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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.
Composition comprising a cerium oxide and a zirconium oxide in a cerium/zirconium atomic proportion of at least 1, wherein the composition 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.
Composition comprising a cerium oxide, a zirconium oxide and a yttrium oxide in a cerium/zirconium atomic proportion of at least 1, wherein the composition 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.
Composition comprising a cerium oxide and a zirconium oxide, in a cerium/zirconium atomic proportion of at least 1, and at least one oxide chosen from scandium oxide and rare-earth metal oxides with the exception of cerium oxide, wherein the composition exhibits a specific surface, after calcination for 6 hours at 900° C., of at least 45 m2/g.
Composition comprising a cerium oxide and a zirconium oxide, in a cerium/zirconium atomic proportion of at least 1, and at least one oxide chosen from scandium oxide and rare-earth metal oxides with the exception of cerium oxide, wherein the composition 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.
Dependencies are inferred from the claim text.