US4091072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exhaust gas conversion process and catalyst
Assignee: Union Oil Company of California
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Filing: 1977-03-07
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Granted: 1978-05-23
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Expires: 1997-03-07
Abstract
Abstract A multi-catalyst system is provided which is effective for the conversion of nitrogen oxides, carbon monoxide and hydrocarbons in near stoichiometric engine exhaust gases in a single conversion zone to which no additional air is admitted. The system comprises at least two separate but contiguous components. The first component comprises a porous inert support having dispersed thereon rhodium plus nickel and/or cobalt, and is essentially free of platinum and palladium. The second component comprises a porous inert support having dispersed thereon platinum and/or palladium, with or without nickel and/or cobalt, and is essentially free of rhodium.
Inventors
- 👤 Dennis P. McArthur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:45
CPC Classifications
B; B01; B01J; B01J35/00; B01J35/19; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01D53/9459; B01D53/9463; B01D53/9472; B01J23/00; B01J23/70; B01J23/89; B01D2255/00; B01D2255/10; B01D2255/102; B01D2255/1021; B01D2255/1023; B01D2255/1025; B01D2255/20; B01D2255/207; B01D2255/20746; B01D2255/20753; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
114 words
A method for the conversion of nitrogen oxides, carbon monoxide and hydrocarbons in near stoichiometric engine exhaust gases which comprises passing said exhaust gases under conversion conditions through a two-catalyst system to which no air is admitted downstream from the inlet thereto, said system comprising two contiguous catalytic components, A and B, segregated in separate longitudinal zones of said system, component A comprising a porous, inert support having dispersed thereon 1-20 weight % of nickel and/or cobalt and a smaller proportion of rhodium, and being essentially free of platinum and palladium, component B comprising a porous inert support having dispersed thereon a minor proportion of platinum and/or palladium and being essentially free of rhodium.
Claim 2
Independent Claim
114 words
A method for the conversion of nitrogen oxides, carbon monoxide and hydrocarbons in near stoichiometric engine exhaust gases which comprises passing said exhaust gases under conversion conditions through a two-catalyst system to which no air is admitted downstream from the inlet thereto, said system comprising two contiguous catalytic components, A and B, segregated in separate longitudinal zones of said system, component A comprising a porous, inert support having dispersed thereon 1-20 weight % of nickel and/or cobalt and a smaller proportion of rhodium, and being essentially free of platinum and palladium, component B comprising a porous inert support having dispersed thereon a minor proportion of platinum and/or palladium and being essentially free of rhodium.
Claim 3
Dependent Claim
22 words
A method as defined in claim 1 wherein said exhaust gases are contacted first with component A and then with component B.
Claim 4
Dependent Claim
22 words
A method as defined in claim 1 wherein said exhaust gases are contacted first with component B and then with component A.
Claim 5
Dependent Claim
34 words
A method as defined in claim 1 wherein said components A and B are applied as a coating to separate ceramic monoliths having a honeycomb structure, said monoliths being co-axially aligned with each other.
Claim 6
Dependent Claim
43 words
A method as defined in claim 1 wherein said component A is applied as a coating to one longitudinal zone of a ceramic monolith having a honeycomb structure, and said component B is applied as a coating to a separate longitudinal zone thereof.
Claim 7
Dependent Claim
58 words
A method as defined in claim 5 wherein said component A is distributed over a zone A' extending from one end of said monolith a distance between about 1/5 and 4/5 of the length thereof, and component B is distributed over a zone B' extending from the opposite end of said monolith to the beginning of zone A'.
Claim 8
Dependent Claim
45 words
A method as defined in claim 1 wherein said components A and B are in the form separately consolidated granules having an average diameter between about 1/32 and 1/4 inch, said separately consolidated granules being segregated from each other at opposite ends of said system.
Claim 9
Dependent Claim
29 words
A method as defined in claim 1 wherein the weight-percent of rhodium in said two-catalyst system is about 1/5 to 1/100 the weight-percent of total platinum and palladium therein.
Claim 10
Dependent Claim
25 words
A method as defined in claim 1 wherein said component B also comprises a minor proportion of cobalt and/or nickel dispersed on said porous support.
Claim 11
Dependent Claim
105 words
An exhaust gas conversion catalyst comprising a ceramic monolith having a honeycomb structure, the interior channels of one end of said monolith being coated with a catalyst component A, and the interior channels of the opposite end of said monolith being coated with a separate catalyst component B, and wherein component A comprises a porous inert support having dispersed thereon 1-20 weight % of nickel and/or cobalt and a smaller proportion of rhodium, and being essentially free of platinum and palladium, and component B comprises a porous inert support having dispersed thereon a minor proportion of platinum and/or palladium and being essentially free of rhodium.
Claim 12
Dependent Claim
105 words
An exhaust gas conversion catalyst comprising a ceramic monolith having a honeycomb structure, the interior channels of one end of said monolith being coated with a catalyst component A, and the interior channels of the opposite end of said monolith being coated with a separate catalyst component B, and wherein component A comprises a porous inert support having dispersed thereon 1-20 weight % of nickel and/or cobalt and a smaller proportion of rhodium, and being essentially free of platinum and palladium, and component B comprises a porous inert support having dispersed thereon a minor proportion of platinum and/or palladium and being essentially free of rhodium.
Claim 13
Dependent Claim
58 words
A catalyst as defined in claim 10 wherein said component A is distributed over a zone A' extending from one end of said monolith a distance between about 1/5 and 4/5 of the length thereof, and component B is distributed over a zone B' extending from the opposite end of said monolith to the beginning of zone A'.
Claim 14
Dependent Claim
26 words
A catalyst as defined in claim 11 wherein the weight-percent of rhodium therein is about 1/5 to 1/100 the weight-percent of total platinum and palladium therein.
Claim 15
Dependent Claim
25 words
A catalyst as defined in claim 10 wherein said component B also comprises a minor proportion of nickel and/or cobalt dispersed on said porous support.
Claim 16
Dependent Claim
41 words
A catalyst as defined in claim 13 which also comprises a third separate but contiguous component, C, comprising an inert, porous support having dispersed thereon a minor proportion of platinum and/or palladium, and being essentially free of nickel, cobalt and rhodium.
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) | 1981-05-22 | 1981-11-21 | 1982-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-22 | 1985-11-21 | 1986-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-22 | 1989-11-21 | 1990-05-23 | $7700.00 | Window Closed / Lapsed |