US3873469A
Expired / Lapsed
US
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Support coatings for catalysts
Assignee: Corning Glass Works
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Filing: 1972-04-12
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Granted: 1975-03-25
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Expires: 1992-04-12
Abstract
Abstract Catalytic devices employing novel multiple-layer support coatings in combination with known base and noble metal catalysts are described. The devices are generally useful as supported catalyst systems and particularly suitable for use in the treatment of automotive exhaust and other waste gases. The multiple-layer support coatings typically comprise a base oxide layer composed of alumina, silica or mixtures thereof and at least one covering layer of a different composition composed of an oxide selected from the group consisting of silica, titania, zirconia, tin oxide and manganese oxide; these multiple coatings are found to enhance and/or stabilize the activity of known catalysts to a degree not demonstrated by either single-oxide or mixed-oxide support coatings used in the prior art. Also disclosed are novel deposition methods, generally useful in the deposition of the coatings of the present invention, comprising the alkoxide impregnation of a support structure and the subsequent in situ hydrolysis of the alkoxide to form an adherent hydrous oxide coating.
Inventors
- 👤 Gordon F Foster
- 👤 Helmuth E Meissner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:25
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/02; B01J37/024; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01J23/00; B01J23/38; B01J23/40; B01J23/70; B01J23/76; B01J23/84; B01J23/85; B01J23/86; B01J23/868; B01J37/0244
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
103 words
A CATALYTIC DEVICE COMPRISING A REFRACTORY SUPPORT STRUCTURE, A REFRACTORY METAL OXIDE CATALYST SUPPORT COATING COVERING AT LEAST A PORTION OF SAID SUPPORT STRUCTURE, AND A CATALYST SUPPORTED ON SAID SUPPORT COATING, WHEREIN THE CATALYST SUPPORT COATING CONSISTS OF A MULTI-LAYER OXIDE COATING OF AT LEAST TWO LAYERS WHICH COMPRISES A BASE LAYER AND AT LEAST ONE COVERING LAYER DIFFERING IN COMPOSITION FROM SAID BASE LAYER, SAID BASE LAYER CONSISTING OF SILICA, ALUMNA, AND MIXTURES THEREOF, AND EACH OF SAID COVERING LAYERS CONSISTING OF SILICA, T OF AN OXIDE SELECTED FROM THE GROUP CONSISTING OF SILICA, TITANIA, ZIRCONIA, TIN OXIDE AND MANGANESE OXIDE.
Claim 2
Dependent Claim
103 words
A CATALYTIC DEVICE COMPRISING A REFRACTORY SUPPORT STRUCTURE, A REFRACTORY METAL OXIDE CATALYST SUPPORT COATING COVERING AT LEAST A PORTION OF SAID SUPPORT STRUCTURE, AND A CATALYST SUPPORTED ON SAID SUPPORT COATING, WHEREIN THE CATALYST SUPPORT COATING CONSISTS OF A MULTI-LAYER OXIDE COATING OF AT LEAST TWO LAYERS WHICH COMPRISES A BASE LAYER AND AT LEAST ONE COVERING LAYER DIFFERING IN COMPOSITION FROM SAID BASE LAYER, SAID BASE LAYER CONSISTING OF SILICA, ALUMNA, AND MIXTURES THEREOF, AND EACH OF SAID COVERING LAYERS CONSISTING OF SILICA, T OF AN OXIDE SELECTED FROM THE GROUP CONSISTING OF SILICA, TITANIA, ZIRCONIA, TIN OXIDE AND MANGANESE OXIDE.
Claim 3
Dependent Claim
22 words
A device according to claim 1 wherein the catalyst support coating comprises a base layer and from one to two covering layers.
Claim 4
Dependent Claim
35 words
A device according to claim 2 wherein the refractory support structure is a monolithic honeycomb structure composed principally of refractory compounds selected from the group consisting of silica, alumina, zirconia, magnesia, petalite, cordierite and spodumene.
Claim 5
Dependent Claim
39 words
A device according to claim 3 wherein the catalyst support coating comprises a base layer of alumina and a single covering layer of an oxide selected from the group consisting of titania, silica, zirconia, tin oxide and manganese oxide.
Claim 6
Dependent Claim
30 words
A device according to claim 3 wherein the catalyst support coating comprises a base layer of alumina, a first covering layer of zirconia and a second covering layer of titania.
Claim 7
Dependent Claim
27 words
A device according to claim 3 wherein the catalyst is a noble metal selected from the group consisting of platinum, palladium, rhodium, iridium, ruthenium and mixtures thereof.
Claim 8
Dependent Claim
26 words
A device according to claim 3 wherein the catalyst is a base metal catalyst selected from the group consisting of transition metal oxides, chromites and ferrites.
Claim 9
Dependent Claim
14 words
A device according to claim 7 wherein the base metal catalyst is copper chromite.
Claim 10
Dependent Claim
111 words
In a catalytic device comprising a refractory support structure, a catalyst support coating covering at least a portion of said structure, and a catalyst supported on said support coating, the improvement which comprises, in place of the catalyst support coating a multi-layer catalyst support coating of at least two layers comprising a base layer and from one to two covering layers differing in composition from said base layer, said base layer consisting essentially of oxides selected from the group consistiNg of alumina, silica and mixtures thereof, and each of said surface layers consisting essentially of an oxide selected from the group consisting of silica, titania, zirconia, tin oxide and manganese oxide.
Claim 11
Dependent Claim
111 words
In a catalytic device comprising a refractory support structure, a catalyst support coating covering at least a portion of said structure, and a catalyst supported on said support coating, the improvement which comprises, in place of the catalyst support coating a multi-layer catalyst support coating of at least two layers comprising a base layer and from one to two covering layers differing in composition from said base layer, said base layer consisting essentially of oxides selected from the group consistiNg of alumina, silica and mixtures thereof, and each of said surface layers consisting essentially of an oxide selected from the group consisting of silica, titania, zirconia, tin oxide and manganese oxide.
Claim 12
Dependent Claim
160 words
A process for depositing a multi-layer catalyst support coating of at least two layers on a refractory support structure which comprises: a. coating the refractory support structure with the alkoxides of at least one metal selected from the group consisting of silicon and aluminum to form a base layer thereon, said alkoxides having alkoxy groups which contain from one to four carbon atoms and which are readily hydrolyzable; b. hydrolyzing the base layer in situ on the refractory support structure to convert said alkoxides to the hydrous oxides of the selected metals; c. firing the hydrous oxide base layer at a temperature in the range of about 300*-600*C. for about 1-24 hours to dehydrate the base layer; and d. providing on the base layer at least one oxide surface layer differing in composition from said base layer, said oxide surface layer being composed of an oxide selected from the group consisting of silica, titania, zirconia, tin oxide and manganese oxide.
Claim 13
Dependent Claim
160 words
A process for depositing a multi-layer catalyst support coating of at least two layers on a refractory support structure which comprises: a. coating the refractory support structure with the alkoxides of at least one metal selected from the group consisting of silicon and aluminum to form a base layer thereon, said alkoxides having alkoxy groups which contain from one to four carbon atoms and which are readily hydrolyzable; b. hydrolyzing the base layer in situ on the refractory support structure to convert said alkoxides to the hydrous oxides of the selected metals; c. firing the hydrous oxide base layer at a temperature in the range of about 300*-600*C. for about 1-24 hours to dehydrate the base layer; and d. providing on the base layer at least one oxide surface layer differing in composition from said base layer, said oxide surface layer being composed of an oxide selected from the group consisting of silica, titania, zirconia, tin oxide and manganese oxide.
Claim 14
Dependent Claim
22 words
A process according to claim 10 wherein the lower alkoxides are selected from the group consisting of aluminum triisopropoxide and silicon tetramethoxide.
Claim 15
Dependent Claim
39 words
A process according to claim 10 wherein the hydrolysis of the base layer in situ is carried out by contact with steam at a temperature of at least about 100*C. and a pressure of at least about 14.7 psi.
Claim 16
Dependent Claim
36 words
A process according to claim 10 wherein the hydrolysis of the base layer in situ is carried out by contact with a liquid selected from the group consisting of water and aqueous solutions of ammonium hydroxide.
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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |