Ceric oxide particulates having improved morphology
US5279789A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 1992 |
| Grant date | Jan 18, 1994 |
| Priority date | — |
| Expiry date | Jul 28, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/16
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Ceric oxide particulates having a specific surface of at least 190 m.sup.2 /g, measured after calcination at a temperature of from 350.degree. to 450.degree. C., and a specific surface of at least 15 m.sup.2 /g after calcination at 800.degree. C., are prepared by (a) suspending, in an aqueous solution of a decomposable base, a ceric hydroxide of the formula (I): EQU Ce(M).sub.x (OH).sub.y (NO.sub.3).sub.z (I) wherein M is an alkali metal or a quaternary ammonium radical; x is a number ranging from 0.01 to 0.2; y is such that y=4-z+x; and z is a number ranging from 0.4 to 0.7; (b) heating the resulting suspension in a confined reaction zone to a temperature and pressure respectively lower than its critical temperature and pressure; (c) cooling such reaction medium and permitting it to return to atmospheric pressure; (d) separating the ceric hydroxide thus treated; and (e) calcining the separated ceric hydroxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.