US4556646A
Expired / Lapsed
US
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Manufacture of noble metal/zeolite catalysts
Assignee: Chevron USA Inc
•
Filing: 1984-11-19
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Granted: 1985-12-03
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Expires: 2004-11-19
Abstract
Abstract A simplified method of manufacture of noble metal/zeolite catalysts involves impregnation of the formed catalyst base with a solution of the noble metal and an ammonium salt. Catalysts having a highly uniform radial distribution of the noble metal are prepared.
Inventors
- 👤 Richard D. Bezman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:20
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/064; B01J29/068
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
149 words
In a process for preparing a catalyst comprising an inorganic oxide component, a zeolite component, and a noble metal component, which process comprises the steps of: (a) forming a particulate catalyst base containing the inorganic oxide component and the zeolite component; (b) impregnating the catalyst base with an impregnating solution containing a soluble salt of the noble metal component; and (c) drying and calcining the impregnated catalyst base; and the improvement which comprises: (a') using as the impregnating solution in step (b) a solution which also contains a soluble ammonium salt; and (b') allowing the impregnated base to stand, between steps (b) and (c), for a time sufficient to produce in the finished calcined catalyst a radial distribution of noble metal such that the concentration of noble metal at the center of the catalyst is at least about 30% of the concentration at the outside edges of the catalyst.
Claim 2
Dependent Claim
149 words
In a process for preparing a catalyst comprising an inorganic oxide component, a zeolite component, and a noble metal component, which process comprises the steps of: (a) forming a particulate catalyst base containing the inorganic oxide component and the zeolite component; (b) impregnating the catalyst base with an impregnating solution containing a soluble salt of the noble metal component; and (c) drying and calcining the impregnated catalyst base; and the improvement which comprises: (a') using as the impregnating solution in step (b) a solution which also contains a soluble ammonium salt; and (b') allowing the impregnated base to stand, between steps (b) and (c), for a time sufficient to produce in the finished calcined catalyst a radial distribution of noble metal such that the concentration of noble metal at the center of the catalyst is at least about 30% of the concentration at the outside edges of the catalyst.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein the inorganic oxide component comprises alumina.
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein the zeolite component comprises a Y-type zeolite.
Claim 5
Dependent Claim
12 words
The process of claim 3 wherein the zeolite component is LZ-20 zeolite.
Claim 6
Dependent Claim
24 words
The process of claim 1 wherein the ratio by weight of the inorganic oxide component to the zeolite component is between 1:4 and 4:1.
Claim 7
Dependent Claim
12 words
The process of claim 1 wherein the noble metal component comprises palladium.
Claim 8
Dependent Claim
23 words
The process of claim 6 wherein the soluble salt of the noble metal component is a salt of the tetra(ammine) palladium (II) cation.
Claim 9
Dependent Claim
21 words
The process of claim 1 wherein the noble metal component constitutes from 0.1 to 5.0 percent by weight of the catalyst.
Claim 10
Dependent Claim
12 words
The process of claim 1 wherein the ammonium salt is ammonium nitrate.
Claim 11
Dependent Claim
42 words
The process of claim 1 wherein the radial distribution of the noble metal is such that the concentration of noble metal at the center of the catalyst is at least about 80% of the concentration at the outside edges of the catalyst.
Claim 12
Dependent Claim
28 words
The process of claim 1 wherein the impregnating solution contains a quantity of ammonium salt equivalent to at least 100% of the ion-exchange capacity of the zeolite component.
Claim 13
Dependent Claim
20 words
The process of claim 1 wherein the impregnated base is allowed to stand for at least 1 hour before drying.
Claim 14
Dependent Claim
20 words
The process of claim 12 wherein the impregnated base is allowed to stand for at least 2 hours before drying.
Claim 15
Dependent Claim
13 words
The process of claim 1 wherein the catalyst base is rehydrated before impregnation.
Claim 16
Dependent Claim
24 words
The process of claim 14 wherein the rehydration is to a moisture level of at least 10 wt. % of the dry catalyst base.
Claim 17
Dependent Claim
15 words
The process of claim 14 wherein the rehydration is achieved by standing in ambient air.
Claim 18
Dependent Claim
139 words
In a process for preparing a catalyst comprising alumina, LZ-20 zeolite, and palladium, which process comprises the steps of: (a) forming a catalyst base containing the alumina and the LZ-20 zeolite; (b) impregnating the catalyst base with an impregnating solution containing a salt of the tetra(ammine) palladium (II) ion; and (c) drying and calcining the impregnated catalyst base; and the improvement which comprises: (a') using as the impregnating solution in step (b) a solution which also contains a soluble ammonium salt; and (b') allowing the impregnated base to stand, between steps (b) and (c), for a time sufficient to produce in the finished calcined catalyst a radial distribution of noble metal such that the concentration of noble metal at the center of the catalyst is at least about 30% of the concentration at the outside edges of the catalyst.
Claim 19
Dependent Claim
139 words
In a process for preparing a catalyst comprising alumina, LZ-20 zeolite, and palladium, which process comprises the steps of: (a) forming a catalyst base containing the alumina and the LZ-20 zeolite; (b) impregnating the catalyst base with an impregnating solution containing a salt of the tetra(ammine) palladium (II) ion; and (c) drying and calcining the impregnated catalyst base; and the improvement which comprises: (a') using as the impregnating solution in step (b) a solution which also contains a soluble ammonium salt; and (b') allowing the impregnated base to stand, between steps (b) and (c), for a time sufficient to produce in the finished calcined catalyst a radial distribution of noble metal such that the concentration of noble metal at the center of the catalyst is at least about 30% of the concentration at the outside edges of the catalyst.
Claim 20
Dependent Claim
42 words
A process of claim 17 wherein the radial distribution of the noble metal is such that the concentration of noble metal at the center of the catalyst is at least about 80% of the concentration at the outside edges of the catalyst.
Claim 21
Dependent Claim
9 words
A catalyst prepared by the process of claim 1.
Claim 22
Dependent Claim
9 words
A catalyst prepared by the process of claim 17.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-02 | 1989-06-03 | 1989-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-02 | 1993-06-03 | 1993-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-02 | 1997-06-03 | 1997-12-03 | $7700.00 | Window Closed / Lapsed |