Composition based on cerium oxide and on zirconium oxide with a high specific surface and a high oxygen storage capacity, process of preparation and use in catalysis
US6228799A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1999 |
| Grant date | May 8, 2001 |
| Priority date | — |
| Expiry date | Jun 3, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
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.degree. C. of at least 35 m.sup.2 /g and an oxygen storage capacity at 400.degree. C. of at least 1.5 ml of O.sub.2 /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.sup.- /Zr.ltoreq.1.65. The composition thus obtained is used in the manufacture of multi-functional catalysts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.