US3856706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High surface area siliceous support
Assignee: 3M Co
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Filing: 1972-06-08
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Granted: 1974-12-24
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Expires: 1992-06-08
Abstract
Abstract A high specific surface area silica for support of e.g., platinum catalysts is obtained by acid leaching of a ceramic, particularly a corrugated structure, containing a cordierite phase.
Inventors
- 👤 H Harrison
- 👤 M Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:29
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/944; B01J; B01J21/00; B01J21/16; B01J37/00; B01J37/06
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
91 words
PROCESS FOR THE PRODUCTION OF A HIGH SPECIFIC SURFACE AREA CATALYST SUPPORT WHICH COMPRISES SUBJECTING A FIRED CERAMIC COMPRISING CORDIERITE AND OF DESIRED GEOMETRICAL SHAPED AND STRUCTURE TO THE LEACHING JACTION OF AN AQUEOUS ACID; FOR A TIME SUFFICIENT TO REMOVE AT LEAST A PORTION OF THE MAGNESIUM AND ALUMINUM COMBINED IN THE CORDIERTE OF SAID FIRED CERAMIC FOLLOWED BY HEATING TO A TEMPERATURE NO HIGHER THAN ABOUT 1,000*C.; SAID ACID BEING CHARACTERIZED BY HAING A DISSOLCIATION CONSTANT IN WATER OF AT LEAST 1X10**5 AND FORMING SOLUBLE MAGNESIUM AND ALUMINUM SALTS.
Claim 2
Dependent Claim
91 words
PROCESS FOR THE PRODUCTION OF A HIGH SPECIFIC SURFACE AREA CATALYST SUPPORT WHICH COMPRISES SUBJECTING A FIRED CERAMIC COMPRISING CORDIERITE AND OF DESIRED GEOMETRICAL SHAPED AND STRUCTURE TO THE LEACHING JACTION OF AN AQUEOUS ACID; FOR A TIME SUFFICIENT TO REMOVE AT LEAST A PORTION OF THE MAGNESIUM AND ALUMINUM COMBINED IN THE CORDIERTE OF SAID FIRED CERAMIC FOLLOWED BY HEATING TO A TEMPERATURE NO HIGHER THAN ABOUT 1,000*C.; SAID ACID BEING CHARACTERIZED BY HAING A DISSOLCIATION CONSTANT IN WATER OF AT LEAST 1X10**5 AND FORMING SOLUBLE MAGNESIUM AND ALUMINUM SALTS.
Claim 3
Dependent Claim
16 words
The process according to claim 1 wherein the fired ceramic comprises from 30% to 100% cordierite.
Claim 4
Dependent Claim
18 words
The process according to claim 2 wherein the fired ceramic has from 25 to 50% of open space.
Claim 5
Dependent Claim
14 words
The process according to claim 3 wherein nitric acid is employed as the acid.
Claim 6
Dependent Claim
24 words
The process according to claim 4 wherein leaching is effected at the boiling point of concentrated nitric acid for from 2 to 24 hours.
Claim 7
Dependent Claim
68 words
The process according to claim 4 wherein a corrugated ceramic structure having about 30 to 40% open space by volume and comprising about 65 to 75% cordierite, 15 to 25% alumina and 10 to 15% mullite is boiled for from 5 to 24 hours in aqueous nitric acid containing about 40 to about 75 wt.% HNO3 and thereafter after washing, is fired at a temperature below 800* C.
Claim 8
Dependent Claim
61 words
A high specific surface area rigid catalyst support having thin sectioned members and relatively large geometrical surface area comprising a silica phase of porous structure characterized by a relative abundance of relatively large holes of about 1 to 50 microns and a substantial volume of very small pores of about 0.001 to 0.1 microns said silica phase being pseudomorphous after cordierite.
Claim 9
Dependent Claim
61 words
A high specific surface area rigid catalyst support having thin sectioned members and relatively large geometrical surface area comprising a silica phase of porous structure characterized by a relative abundance of relatively large holes of about 1 to 50 microns and a substantial volume of very small pores of about 0.001 to 0.1 microns said silica phase being pseudomorphous after cordierite.
Claim 10
Dependent Claim
32 words
A high specific surface area rigid catalyst support according to claim 7 additionally comprising an adherent coating of high surface area alumina distributed over at least part of the geometrical surface thereof.
Claim 11
Dependent Claim
18 words
A rigid catalyst comprising a catalyst support according to claim 7 and a catalyst distributed over said support.
Claim 12
Dependent Claim
14 words
A rigid catalyst according to claim 9 wherein the catalyst is a noble metal.
Claim 13
Dependent Claim
13 words
A rigid catalyst according to claim 10 wherein the noble metal is platinum.
Claim 14
Dependent Claim
35 words
A rigid catalyst according to claim 11 wherein the support is a corrugated ceramic structure comprising about 25 to 50% of open space and comprising, in addition to the silica phase, also mullite and alumina.
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) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |