US4663137A
Expired / Lapsed
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Process for producing cerium oxide particulates
Assignee: Rhone Poulenc Specialites Chimiques
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Filing: 1985-02-20
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Granted: 1987-05-05
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Expires: 2005-02-20
Abstract
Abstract Morphologically improved cerium oxide particulates useful, e.g., as catalysts/catalyst supports, and having a B.E.T. specific surface of at least 85±5 m 2 /g, measured at a temperature ranging from 350° C. to 450° C., are prepared by hydrolyzing an aqueous solution of a cerium (IV) salt in an acidic medium, filtering the precipitate of hydrolysis which results, washing and optionally drying said precipitate, and then calcining same.
Inventors
- 👤 Jean-Yves Chane-Ching
- 👤 Jean-Yves Dumousseau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:11
CPC Classifications
C; C01; C01F; C01F17/00; B; B01; B01J; B01J23/00; B01J23/10; C01F17/20; C01F17/206; C01F17/224; C01F17/235; C01F17/276; C01P; C01P2002/00; C01P2002/70; C01P2002/77; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/30; C01P2004/32; C01P2006/00; C01P2006/12; C01P2006/13
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
68 words
A process for the preparation of ceric oxide particulates having a B.E.T. specific surface of at least 85±5 m 2 /g, measured at a temperature ranging from 350° C. to 450° C., comprising hydrolyzing an aqueous solution of a cerium (IV) salt in a nitric acid medium, filtering the precipitate of hydrolysis which results, washing in an organic solvent and optionally drying said precipitate, and thence calcining same.
Claim 2
Dependent Claim
68 words
A process for the preparation of ceric oxide particulates having a B.E.T. specific surface of at least 85±5 m 2 /g, measured at a temperature ranging from 350° C. to 450° C., comprising hydrolyzing an aqueous solution of a cerium (IV) salt in a nitric acid medium, filtering the precipitate of hydrolysis which results, washing in an organic solvent and optionally drying said precipitate, and thence calcining same.
Claim 3
Dependent Claim
30 words
The process as defined by claim 1, said aqueous solution of a cerium (IV) salt comprising an aqueous solution of ceric nitrate or an aqueous solution of ammonium ceric nitrate.
Claim 4
Dependent Claim
28 words
The process as defined by claim 1, wherein the concentration of cerium salt in said solution, expressed as cerium (IV), ranges from 0.3 to 2 moles per liter.
Claim 5
Dependent Claim
16 words
The process as defined by claim 1, said medium of hydrolysis comprising distilled or de-ionized water.
Claim 6
Dependent Claim
21 words
The process as defined by claim 1, said medium of hydrolysis having an acidity ranging from 10 -2 to 1.0 N.
Claim 7
Dependent Claim
15 words
The process as defined by claim 5, said acidity emanating from the commencement of hydrolysis.
Claim 8
Dependent Claim
19 words
The process as defined by claim 5, said acidity emanating by nitric acid addition to the medium of hydrolysis.
Claim 9
Dependent Claim
16 words
The process as defined by claim 5, said acidity emanating by addition of a ceric nitrate.
Claim 10
Dependent Claim
22 words
The process as defined by claim 8, said ceric nitrate solution added having an acidity of from 0.3 N to 1 N.
Claim 11
Dependent Claim
42 words
The process as defined by claim 1, wherein the amount of the aqueous solution of cerium (IV) salt and the medium of hydrolysis is such that the equivalent final concentration of cerium (IV) therein ranges from 0.2 to 0.8 mole per liter.
Claim 12
Dependent Claim
23 words
The process as defined by claim 1, wherein the temperature of the hydrolysis reaction medium ranges from about 70° C. to 100° C.
Claim 13
Dependent Claim
19 words
The process as defined by claim 1, wherein the temperature of the hydrolysis reaction medium is its reflux temperature.
Claim 14
Dependent Claim
33 words
The process as defined by claim 11, wherein the temperature of the hydrolysis reaction medium is maintained for from 1 to 24 hours following addition of the solution of the cerium (IV) salt.
Claim 15
Dependent Claim
18 words
The process as defined by claim 1, said precipitate being washed at least once with an organic solvent.
Claim 16
Dependent Claim
14 words
The process as defined by claim 14, said organic solvent comprising ethanol or isopropanol.
Claim 17
Dependent Claim
34 words
The process as defined by claim 1, said calcining being carried out at a temperature of from 300° C. to 600° C. for a period of time of about 30 minutes to ten hours.
Claim 18
Dependent Claim
17 words
The process as defined by claim 16, said calcining temperature ranging from 350° C. to 450° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |