US5965481A
Expired / Lapsed
US
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Process for preparing a catalyst suitable for the treatment of exhaust gases from internal combustion engines
Assignee: IFP Energies nouvelles
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Filing: 1994-08-16
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Granted: 1999-10-12
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Expires: 2014-08-16
Abstract
Abstract The invention involves the production of a catalyst that contains (1) at least one refractory inorganic oxide support, (2) at least one iron oxide, and (3) at least one cerium oxide, (4) at least one metal A, for example, from Groups VIB, VIIB, VIII, and IB of the Periodic System and, optionally (5) at least one compound of metal B, for example, from Groups IA, IIA, the rare-earths group, and Group IVB of the Periodic System, deposited in the form of a porous layer ("washcoat") on a ceramic or metal substrate: (a) atomizing an aqueous suspension of at least one powder of the refractory inorganic oxide, cerium salt, iron salt, and optionally salt of the metal B; and/or A (b) resuspending the resultant powder and adding any remainder or all of the compound of metal B, as well as, optionally at least one bonding agent and, optionally at least one mineral acid or organic acid; (c) coating a ceramic or metal substrate is coated with the suspension obtained in step (b); (d) calcining the resultant coated substrate; (e) impregnating the resultant coated and calcined substrate with any remainder or all of the precursor of metal A; and (f) thermally activating said coated, calcined, and impregnated substrate coming from step (e).
Inventors
- 👤 Daniel Durand
- 👤 Gil Mabilon
- 👤 Isabelle Guibard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:05
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J23/00; B01J23/70; B01J23/76; B01J23/83; B01J23/89; B01J23/8933; B01J23/894; B01J37/00; B01J37/0009; B01J37/0027; B01J37/0045; B01J37/02; B01J37/024; B01J37/0248; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
305 words
A process for producing a catalyst that contains at least one refractory inorganic oxide, which is α-alumina, γ-alumina, Δ-alumina, eta-alumina, theta-alumina, kappa-alumina, rho-alumina, chi-alumina, silica, a silica-alumina, a zeolite, a silica-magnesia, titanium oxide, zirconium oxide, or a mixture thereof; at least one iron oxide; at least one cerium oxide; at least one catalytically active metal A from Group VIB, VIIB, VIII or IB of the Periodic System; and optionally at least one compound of metal B from Group IA, IIA, IVB, or rare earths having atomic numbers 57-71 inclusive, all deposited in the form of a porous layer on a ceramic or metal substrate, said process comprising: (a), in an atomizing device having an inlet and an outlet, atomizing an aqueous suspension of at least one powder of said refractory inorganic oxide, at least one soluble cerium salt, at least one soluble iron salt, optionally at least one portion of at least one insoluble compound and/or at least one soluble salt of said metal B, and optionally at least one portion of at least one metal A that has been previously deposited by impregnation of at least one of a precursor thereof on at least one of the solid constituents that are present, so as to recover a powder, and optionally calcining the resultant powder; (b) transferring the resultant powder from step (a) back into suspension while optionally adding said compound of metal B, as well as, optionally at least one bonding agent and optionally at least one mineral acid or organic acid; (c) coating a ceramic or metal substrate with the suspension obtained in step (b); (d) calcining the coated substrate from step (c); (e) impregnating said coated and calcined substrate with any remainder or all of said precursor of metal A; and (f) heat-activating said coated, calcined, and impregnated substrate obtained from (e).
Claim 2
Dependent Claim
305 words
A process for producing a catalyst that contains at least one refractory inorganic oxide, which is α-alumina, γ-alumina, Δ-alumina, eta-alumina, theta-alumina, kappa-alumina, rho-alumina, chi-alumina, silica, a silica-alumina, a zeolite, a silica-magnesia, titanium oxide, zirconium oxide, or a mixture thereof; at least one iron oxide; at least one cerium oxide; at least one catalytically active metal A from Group VIB, VIIB, VIII or IB of the Periodic System; and optionally at least one compound of metal B from Group IA, IIA, IVB, or rare earths having atomic numbers 57-71 inclusive, all deposited in the form of a porous layer on a ceramic or metal substrate, said process comprising: (a), in an atomizing device having an inlet and an outlet, atomizing an aqueous suspension of at least one powder of said refractory inorganic oxide, at least one soluble cerium salt, at least one soluble iron salt, optionally at least one portion of at least one insoluble compound and/or at least one soluble salt of said metal B, and optionally at least one portion of at least one metal A that has been previously deposited by impregnation of at least one of a precursor thereof on at least one of the solid constituents that are present, so as to recover a powder, and optionally calcining the resultant powder; (b) transferring the resultant powder from step (a) back into suspension while optionally adding said compound of metal B, as well as, optionally at least one bonding agent and optionally at least one mineral acid or organic acid; (c) coating a ceramic or metal substrate with the suspension obtained in step (b); (d) calcining the coated substrate from step (c); (e) impregnating said coated and calcined substrate with any remainder or all of said precursor of metal A; and (f) heat-activating said coated, calcined, and impregnated substrate obtained from (e).
Claim 3
Dependent Claim
137 words
A process according to claim 1, wherein step (a) includes: (i) grinding dry or wet said refractory inorganic oxide and, optionally said insoluble compound of metal B, in such a way as to obtain a powder of reduced average particle size; (ii) preparing an aqueous suspension of said ground solid constituents with the addition of at least one soluble iron salt and at least one soluble cerium salt, optionally at least one insoluble or soluble compound of metal B, optionally at least one metal A that is preimpregnated on at least one of said ground solid constituents and, optionally, at least one mineral acid or inorganic acid; (iii) allowing the suspension thus formed is allowed to cure; (iv) atomizing said suspension in an atomization device and recovering a powder; and optionally (v) calcining the powder thus recovered.
Claim 4
Dependent Claim
23 words
A process according to claim 2, wherein the average particle size of the powder recovered from (a)(i) is between 0.1 and 100 microns.
Claim 5
Dependent Claim
23 words
A process according to claim 2, wherein the suspension to be atomized has a potential dry-material content between 5 and 60% by weight.
Claim 6
Dependent Claim
25 words
A process according to claim 2, wherein in (a) (iii) the curing time of the suspension to be atomized is between 0.5 and 100 hours.
Claim 7
Dependent Claim
19 words
A process according to claim 5, wherein in (a) (iii) the curing temperature is between 0 and 50° C.
Claim 8
Dependent Claim
28 words
A process according to claim 1, wherein the cerium oxide content of the powder recovered after atomization is between 0.1 and 40% determined after calcination at 1000° C.
Claim 9
Dependent Claim
28 words
A process according to claim 1, wherein the iron oxide content of the powder recovered after atomization is between 0.1 and 10% determined after calcination at 1000° C.
Claim 10
Dependent Claim
23 words
A process according to claim 1, wherein metal B is present and is rubidium, calcium, strontium, barium, lanthanum, praseodymium, neodymium, zirconium or titanium.
Claim 11
Dependent Claim
37 words
A process according to claim 1, wherein metal B is present and the content of the compound of metal B of the powder recovered after atomization is between 0 and 10%, determined after calcination at 1000° C.
Claim 12
Dependent Claim
27 words
A process according to claim 1, wherein metal A is platinum, rhodium, palladium, iridium, ruthenium, rhenium, gold, silver, copper, nickel, cobalt, manganese, chromium, molybdenum or mixtures thereof.
Claim 13
Dependent Claim
30 words
A process according to claim 2, wherein the amount of mineral acid added to the aqueous suspension in (a) (ii) is between 0 and 5% by weight of the suspension.
Claim 14
Dependent Claim
28 words
A process according to claim 1, wherein in (a) hot gas at a temperature of 100 to 900° C. is fed to the intake of the atomizing device.
Claim 15
Dependent Claim
29 words
A process according to claim 13, wherein in (a) the temperature of the gas measured at the outlet of the atomizing device is between 100° C. and 600° C.
Claim 16
Dependent Claim
28 words
A process according to claim 1, wherein the powder from atomizing is calcined at a temperature between 150 and 900° C., and preferably between 300 and 700° C.
Claim 17
Dependent Claim
14 words
A process according to claim 1, wherein said metal substrate is an aluminized steel.
Claim 18
Dependent Claim
25 words
A process according to claim 1, wherein said metal substrate is treated, before coating in (c), under an oxidizing atmosphere between 700 and 1100° C.
Claim 19
Dependent Claim
27 words
A process according to claim 1, wherein the quantity of binder added to the aqueous suspension in (b) represents 0 to 10% by weight of said suspension.
Claim 20
Dependent Claim
30 words
A process according to claim 1, wherein the quantity of mineral or organic acid added to the aqueous suspension in (b) represents 0 to 5% by weight of said suspension.
Claim 21
Dependent Claim
44 words
A process according to claim 1, wherein in (c) the substrate is coated with said suspension, then excess suspension present in channels of the substrate is eliminated, and the substrate coated in (d) is calcined at a temperature of between 100 and 800° C.
Claim 22
Dependent Claim
24 words
A process according to claim 1, wherein the weight of the porous layer deposited is between 20 and 200 g per liter of substrate.
Claim 23
Dependent Claim
39 words
A process according to claim 1, wherein in (e) the coated substrate is impregnated with the remainder or all of the precursors of metal A, with a total content of between 0.05 and 10 g per liter of substrate.
Claim 24
Dependent Claim
34 words
A process according to claim 1, wherein in (f) the heat treatment is conducted in an inert, oxidizing, or reducing atmosphere and is carried out at a temperature of between 200 and 900° C.
Claim 25
Dependent Claim
10 words
A catalyst produced according to the process of claim 1.
Claim 26
Dependent Claim
32 words
In the catalytic conversion and/or elimination of pollutants present in the exhaust gases of internal combustion engines, the improvement comprising passing said gases in contact with a catalyst according to claim 24.
Claim 27
Dependent Claim
185 words
In a process for producing a catalyst containing a ceramic or metal substrate having deposited thereon a porous layer of at least one refractory inorganic oxide, which is α-alumina, γ-alumina, Δ-alumina, eta-alumina, theta-alumina, kappa-alumina, rho-alumina, chi-alumina, silica, a silica-alumina, a zeolite, a silica-magnesia, titanium oxide, zirconium oxide, or a mixture thereof; at least one iron oxide; and at least one cerium oxide; at least one metal A and, optionally, at least one compound of metal B; said process comprising forming a powder and applying said powder to said substrate, the improvement in forming said powder which comprises atomizing an aqueous suspension of at least one powder of said refractory inorganic oxide, at least one soluble cerium salt, at least one soluble iron salt, optionally at least one portion of at least one insoluble compound and/or at least one soluble salt of said metal B, and optionally at least one portion of at least one metal A that was previously deposited by impregnation of at least one precursors thereof on at least one of the solid constituents that are present so as to recover a powder.
Claim 28
Dependent Claim
185 words
In a process for producing a catalyst containing a ceramic or metal substrate having deposited thereon a porous layer of at least one refractory inorganic oxide, which is α-alumina, γ-alumina, Δ-alumina, eta-alumina, theta-alumina, kappa-alumina, rho-alumina, chi-alumina, silica, a silica-alumina, a zeolite, a silica-magnesia, titanium oxide, zirconium oxide, or a mixture thereof; at least one iron oxide; and at least one cerium oxide; at least one metal A and, optionally, at least one compound of metal B; said process comprising forming a powder and applying said powder to said substrate, the improvement in forming said powder which comprises atomizing an aqueous suspension of at least one powder of said refractory inorganic oxide, at least one soluble cerium salt, at least one soluble iron salt, optionally at least one portion of at least one insoluble compound and/or at least one soluble salt of said metal B, and optionally at least one portion of at least one metal A that was previously deposited by impregnation of at least one precursors thereof on at least one of the solid constituents that are present so as to recover a powder.
Claim 29
Dependent Claim
10 words
A catalyst as produced by the process of claim 26.
Claim 30
Dependent Claim
19 words
A process according to claim 26, further comprising resuspending the atomized free flowing powder to form a coating suspension.
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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) | 2002-10-11 | 2003-04-12 | 2003-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-11 | 2007-04-12 | 2007-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-11 | 2011-04-12 | 2011-10-12 | $7700.00 | Window Closed / Lapsed |