US4231900A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming activated alumina coating on refractory article and article thereby produced
Assignee: Nissan Motor Co Ltd
•
Filing: 1978-03-31
•
Granted: 1980-11-04
•
Expires: 1998-03-31
Abstract
Abstract A mixture is prepared by mixing alumina sol and activated alumina which contains not less than 60 Wt % of delta-alumina. The mixture is thereafter coated on a relatively small specific surface area monolithic catalyst carrier. After being dried, the coated carrier is fired to give a high specific surface area catalyst carrier.
Inventors
- 👤 Tadanari Kato
- 👤 Tadashi Ikemi
- 👤 Takatoshi Sagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:43
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; C; C04; C04B; C04B41/00; C04B41/45; C04B41/50; C04B41/5025; C04B41/5031; C04B41/80; C04B41/81; C04B41/85; C04B41/87
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
126 words
A method for forming a high surface area coating on the surface of a monolithic catalyst carrier, said method comprising the steps of: preparing a mixture containing not more than 20 parts by weight of alumina sol and one part by weight of activated alumina, said alumina sol containing 3 to 15 Wt % of alumina, said activated alumina containing not less than 60 Wt % of delta-alumina; coating said mixture onto the surface of the catalyst carrier; drying the coated catalyst carrier; and firing the coated catalyst carrier at a temperature in the range of 150° to 850° C. for a time in the range of from 0.5 to 20 hours to form the high surface area coating on the surface of the catalyst carrier.
Claim 2
Independent Claim
126 words
A method for forming a high surface area coating on the surface of a monolithic catalyst carrier, said method comprising the steps of: preparing a mixture containing not more than 20 parts by weight of alumina sol and one part by weight of activated alumina, said alumina sol containing 3 to 15 Wt % of alumina, said activated alumina containing not less than 60 Wt % of delta-alumina; coating said mixture onto the surface of the catalyst carrier; drying the coated catalyst carrier; and firing the coated catalyst carrier at a temperature in the range of 150° to 850° C. for a time in the range of from 0.5 to 20 hours to form the high surface area coating on the surface of the catalyst carrier.
Claim 3
Dependent Claim
32 words
A method as claimed in claim 1, in which said alumina sol is prepared by using alumina whose starting material is boehmite, and the starting material of said activated alumina is boehmite.
Claim 4
Dependent Claim
35 words
A method as claimed in claim 2, further comprising the step of applying an acid or an alkali onto the surface of the catalyst carrier before coating said mixture onto the surface of the same.
Claim 5
Dependent Claim
37 words
A method as claimed in claim 3, further comprising the step of gelling said alumina sol in said mixture by applying an acid or an alkali after coating said mixture onto the surface of the catalyst carrier.
Claim 6
Dependent Claim
19 words
A method as claimed in claim 2, wherein said temperature is in the range of 300° to 700° C.
Claim 7
Dependent Claim
20 words
A method as claimed in claim 5, wherein said time is in the range of from 1 to 5 hours.
Claim 8
Independent Claim
120 words
A method for preparing a catalyst for purification of a high temperature waste gas, comprising the steps of: preparing a mixture containing not more than 20 parts by weight of an alumina sol and one part by weight of activated alumina, said alumina sol containing 3 to 15 Wt% of alumina, said activated alumina containing not less than 60 Wt % of delta-alumina; coating said mixture onto the surface of the catalyst carrier; drying the coated catalyst carrier; firing the coated catalyst carrier at a temperature in the range of 150° to 850° C. for a time in the range of from 0.5 to 20 hours; and immersing the fired coated catalyst carrier in a solution containing a noble metal.
Claim 9
Independent Claim
120 words
A method for preparing a catalyst for purification of a high temperature waste gas, comprising the steps of: preparing a mixture containing not more than 20 parts by weight of an alumina sol and one part by weight of activated alumina, said alumina sol containing 3 to 15 Wt% of alumina, said activated alumina containing not less than 60 Wt % of delta-alumina; coating said mixture onto the surface of the catalyst carrier; drying the coated catalyst carrier; firing the coated catalyst carrier at a temperature in the range of 150° to 850° C. for a time in the range of from 0.5 to 20 hours; and immersing the fired coated catalyst carrier in a solution containing a noble metal.
Claim 10
Dependent Claim
31 words
A method as claimed in claim 7, wherein said alumina sol is prepared by using alumina whose starting material is boehmite, and the starting material of said activated alumina is boehmite.
Claim 11
Independent Claim
124 words
A method for preparing a catalyst for purification of exhaust gases discharged from automobile engines, said method comprising the steps of: preparing a mixture containing not more than 20 parts by weight of an alumina sol and one part by weight of activated alumina, said alumina sol containing 3 to 15 Wt % of alumina, said activated alumina containing not less than 60 Wt % of delta-alumina; coating said mixture onto the surface of the catalyst carrier; drying the coated catalyst carrier; firing the coated catalyst carrier at a temperature in the range of 150° to 850° C. for a time in the range of from 0.5 to 20 hours and immersing the fired coated catalyst carrier in a solution containing a noble metal.
Claim 12
Independent Claim
124 words
A method for preparing a catalyst for purification of exhaust gases discharged from automobile engines, said method comprising the steps of: preparing a mixture containing not more than 20 parts by weight of an alumina sol and one part by weight of activated alumina, said alumina sol containing 3 to 15 Wt % of alumina, said activated alumina containing not less than 60 Wt % of delta-alumina; coating said mixture onto the surface of the catalyst carrier; drying the coated catalyst carrier; firing the coated catalyst carrier at a temperature in the range of 150° to 850° C. for a time in the range of from 0.5 to 20 hours and immersing the fired coated catalyst carrier in a solution containing a noble metal.
Claim 13
Dependent Claim
14 words
A method as claimed in claim 9, wherein said solution contains platinum and palladium.
Claim 14
Dependent Claim
20 words
A method as claimed in claim 9, further comprising firing the fired coated catalyst carrier after immersing in said solution.
Claim 15
Dependent Claim
31 words
A method as claimed in claim 9, wherein said alumina sol is prepared by using alumina whose starting material is boehmite, and the starting material of said activated alumina is boehmite.
Claim 16
Dependent Claim
130 words
A catalyst carrier for carrying a catalytic metal thereon, comprising: a monolithic carrier base; a high surface area coating formed on the surface of said monolithic carrier base, said high surface area coating is formed by firstly preparing a mixture containing not more than 20 parts by weight of alumina sol and one part by weight of activated alumina, said alumina sol containing 3 to 15 Wt % of alumina said activated alumina containing not less than 60 Wt % of delta-alumina, secondly coating said mixture onto the surface of said monolithic carrier base, thirdly drying the coated carrier base, and lastly firing the coated carrier base at a temperature in the range from 150° to 850° C. for a time in the range of from 0.5 to 20 hours.
Claim 17
Dependent Claim
130 words
A catalyst carrier for carrying a catalytic metal thereon, comprising: a monolithic carrier base; a high surface area coating formed on the surface of said monolithic carrier base, said high surface area coating is formed by firstly preparing a mixture containing not more than 20 parts by weight of alumina sol and one part by weight of activated alumina, said alumina sol containing 3 to 15 Wt % of alumina said activated alumina containing not less than 60 Wt % of delta-alumina, secondly coating said mixture onto the surface of said monolithic carrier base, thirdly drying the coated carrier base, and lastly firing the coated carrier base at a temperature in the range from 150° to 850° C. for a time in the range of from 0.5 to 20 hours.
Claim 18
Dependent Claim
32 words
A catalyst as claimed in claim 13, in which said alumina sol is prepared by using alumina whose starting material is boehmite, and the starting material of said activated alumina is boehmite.
Claim 19
Dependent Claim
141 words
A catalyst for purifying exhaust gases from automobile engines, comprising a monolithic carrier, a high surface area coating formed on the surface of said monolithic carrier, said high surface area coating being formed by firstly preparing a mixture containing not more than 20 parts by weight of alumina sol and one part by weight of activated alumina, said alumina sol containing 3 to 15 Wt % of alumina, said activated alumina containing not less than 60 Wt % of delta-alumina, secondary coating said mixture onto the surface of said monolithic carrier, thirdly drying the coated monolithic carrier, fourthly firing the coated catalyst carrier at a temperature in the range of 150° to 850° C. for a time in the range of from 0.5 to 20 hours, and lastly immersing the fired coated monolithic carrier in a solution containing a noble metal.
Claim 20
Dependent Claim
141 words
A catalyst for purifying exhaust gases from automobile engines, comprising a monolithic carrier, a high surface area coating formed on the surface of said monolithic carrier, said high surface area coating being formed by firstly preparing a mixture containing not more than 20 parts by weight of alumina sol and one part by weight of activated alumina, said alumina sol containing 3 to 15 Wt % of alumina, said activated alumina containing not less than 60 Wt % of delta-alumina, secondary coating said mixture onto the surface of said monolithic carrier, thirdly drying the coated monolithic carrier, fourthly firing the coated catalyst carrier at a temperature in the range of 150° to 850° C. for a time in the range of from 0.5 to 20 hours, and lastly immersing the fired coated monolithic carrier in a solution containing a noble metal.
Claim 21
Dependent Claim
32 words
A catalyst as claimed in claim 15, in which said alumina sol is prepared by using alumina whose starting material is boehmite, and the starting material of said activated alumina is boehmite.
References Cited (Backward Citations)
FR1231993A
Cited
US3013903A
Cited
US3013901A
Cited
GB1018034A
Cited
GB1017004A
Cited
US3565830A
Cited
GB1052105A
Cited
US3447893A
Cited
US3554929A
Cited
GB1212889A
Cited
US3734767A
Cited
US3690921A
Cited
US3767453A
Cited
GB1321520A
Cited
US3926702A
Cited
US3842017A
Cited
US3870545A
Cited
US4062810A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-04 | 1984-05-05 | 1984-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-04 | 1988-05-05 | 1988-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-04 | 1992-05-05 | 1992-11-04 | $7700.00 | Window Closed / Lapsed |