Patent US5376610A successfully refreshed from Google Patents.
US5376610A
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Catalyst for exhaust gas purification and method for exhaust gas purification
Assignee: NGK Insulators Ltd
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Filing: 1993-04-12
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Granted: 1994-12-27
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Expires: 2013-04-12
Abstract
Abstract A catalyst for exhaust gas purification has at least one monolith carrier, at least one first catalyst layer having a three-way catalytic activity, provided on the carrier, and a second catalyst layer having a hydrocarbon purification activity, provided on the first catalyst layer. In a gasoline engine automobile provided with the above catalyst for exhaust gas purification in the exhaust gas system, the hydrocarbons present in the exhaust gas can be converted at a high efficiency by introducing secondary air into the exhaust gas in front of the catalyst to make the exhaust gas lean, at the engine start when a large amount of unburnt hydrocarbons are present in the exhaust gas. Further, the engine warm-up property of the automobile can be improved by the heat generated by the catalytic reaction of the hydrocarbons. The catalyst further exhibits a three-way catalytic activity even during the steady state engine operation after warm-up.
Inventors
- 👤 Toshio Takahata
- 👤 Hideharu Ehara
- 👤 Fuminori Yamanashi
- 👤 Katsuhiro Shibata
- 👤 Fumio Abe
- 👤 Tomoharu Kondo
- 👤 Junichi Suzuki
- 👤 Naomi Noda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:33
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/02; B01J37/0234; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J23/00; B01J23/38; B01J23/54; B01J23/56; B01J23/63; B01J37/024; B01J37/0244; B01J37/0248; F; F01; F01N; F01N13/00; F01N13/009; F01N13/0097; F01N3/00; F01N3/08; F01N3/10; F01N3/18; F01N3/20; F01N3/2006; F01N3/2013; F01N3/2026; F01N3/22; F01N3/222; B01D2255/00; B01D2255/10; B01D2255/102; B01D2255/1021; B01D2255/1023; B01D2255/1025; B01D2255/90; B01D2255/902; B01D2255/9022; B01D2255/904; B01D2255/912; B01J23/40; F01N2330/00; F01N2330/02; F01N2330/04; F01N3/24; F01N3/30; F01N3/32; F02; F02B; F02B1/00; F02B1/02; F02B1/04; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 55
Claim 1
Independent Claim
60 words
A catalyst for exhaust gas purification, comprising: at least one monolith carrier; a first catalyst layer having a three-way catalytic activity and comprising Rh as an active component; and a second catalyst layer having a hydrocarbon purification activity provided on said first catalyst layer, said second catalyst layer comprising at least one of Pt and Pd as an active component.
Claim 2
Dependent Claim
60 words
A catalyst for exhaust gas purification, comprising: at least one monolith carrier; a first catalyst layer having a three-way catalytic activity and comprising Rh as an active component; and a second catalyst layer having a hydrocarbon purification activity provided on said first catalyst layer, said second catalyst layer comprising at least one of Pt and Pd as an active component.
Claim 3
Dependent Claim
32 words
The catalyst of claim 1, wherein the second catalyst layer further comprises (i) a substrate composed mainly of at least one of alumina and zeolite, and (ii) a rare earth element oxide.
Claim 4
Dependent Claim
24 words
The catalyst of claim 1, wherein the first catalyst layer further comprises a substrate composed mainly of at least one of alumina and zirconia.
Claim 5
Dependent Claim
17 words
The catalyst of claim 3, wherein the first catalyst layer further comprises a rare earth element oxide.
Claim 6
Dependent Claim
41 words
The catalyst of claim 1, wherein the first catalyst layer includes a plurality of sub-layers, including a first sub-layer and an outermost second sub-layer provided on said first sub-layer, said second sub-layer containing Rh and having an NO x -reducing activity.
Claim 7
Dependent Claim
21 words
The catalyst of claim 1, wherein the monolith carrier has a honeycomb structure and is comprised of a heat-resistant inorganic material.
Claim 8
Dependent Claim
36 words
The catalyst of claim 1, wherein said monolith carrier comprises a honeycomb structure and at least one pair of electrodes electrically connected to said honeycomb structure, said monolith carrier being adapted to generate heat when electrified.
Claim 9
Dependent Claim
18 words
The catalyst of claim 7, wherein said monolith carrier further comprises resistance adjusting means provided between the electrodes.
Claim 10
Dependent Claim
129 words
A catalyst for exhaust gas purification, comprising: at least one monolith carrier having an upstream portion and a downstream portion; a first catalyst layer having a hydrocarbon purification activity provided on said upstream portion of the monolith carrier, said first catalyst layer having an outermost portion comprising at least one of Pt and Pd as an active component; and a second catalyst layer having a three-way catalyst activity provided on said downstream portion of the monolith carrier, said second catalyst layer comprising Rh as an active component, wherein said at least one of Pt and Pd of said first catalyst layer and said Rh of said second catalyst layer are separated from each other to avoid contact between the Rh and said at least one of Pt and Pd.
Claim 11
Dependent Claim
129 words
A catalyst for exhaust gas purification, comprising: at least one monolith carrier having an upstream portion and a downstream portion; a first catalyst layer having a hydrocarbon purification activity provided on said upstream portion of the monolith carrier, said first catalyst layer having an outermost portion comprising at least one of Pt and Pd as an active component; and a second catalyst layer having a three-way catalyst activity provided on said downstream portion of the monolith carrier, said second catalyst layer comprising Rh as an active component, wherein said at least one of Pt and Pd of said first catalyst layer and said Rh of said second catalyst layer are separated from each other to avoid contact between the Rh and said at least one of Pt and Pd.
Claim 12
Dependent Claim
13 words
The catalyst of claim 9, wherein said first catalyst layer comprises mainly Pd.
Claim 13
Dependent Claim
13 words
The catalyst of claim 10, wherein said first catalyst layer consists of Pd.
Claim 14
Dependent Claim
36 words
The catalyst of claim 9, wherein said first catalyst layer includes a plurality of sub-layers, including a first sub-layer, and a second sub-layer provided on said first sub-layer, said outermost portion consisting of said second sub-layer.
Claim 15
Dependent Claim
18 words
The catalyst of claim 12, wherein the second sub-layer contains said at least one of Pt and Pd.
Claim 16
Dependent Claim
13 words
The catalyst of claim 13, wherein the second sub-layer consists essentially of Pd.
Claim 17
Dependent Claim
11 words
The catalyst of claim 14, wherein the first sub-layer comprises Rh.
Claim 18
Dependent Claim
15 words
The catalyst of claim 9, wherein the second catalyst layer is comprised mainly of Rh.
Claim 19
Dependent Claim
13 words
The catalyst of claim 16, wherein the second catalyst layer consists of Rh.
Claim 20
Dependent Claim
29 words
The catalyst of claim 9, wherein the second catalyst layer includes a plurality of sub-layers, including a first sub-layer and an outermost second sub-layer provided on said first sub-layer.
Claim 21
Dependent Claim
11 words
The catalyst of claim 18, wherein said second sub-layer contains Rh.
Claim 22
Dependent Claim
12 words
The catalyst of claim 19, wherein said second sub-layer consists of Rh.
Claim 23
Dependent Claim
17 words
The catalyst of claim 19, wherein said first sub-layer contains at least one of Pt and Pd.
Claim 24
Dependent Claim
40 words
The catalyst of claim 9, wherein said first catalyst layer further comprises Rh which is separated from said at least one of Pt and Pd to prevent contact between the Rh and said at least one of Pt and Pd.
Claim 25
Dependent Claim
40 words
The catalyst of claim 9, wherein the second catalyst layer further comprises at least one of Pt and Pd which is separated from the Rh to prevent contact between the Rh and the at least one of Pt and Pd.
Claim 26
Dependent Claim
22 words
The catalyst of claim 9, wherein the first catalyst layer further comprises a substrate including at least one of alumina and zeolite.
Claim 27
Dependent Claim
11 words
The catalyst of claim 24, wherein said substrate further includes zirconia.
Claim 28
Dependent Claim
17 words
The catalyst of claim 24, wherein said first catalyst layer further comprises a rare earth element oxide.
Claim 29
Dependent Claim
22 words
The catalyst of claim 9, wherein the second catalyst layer further comprises a substrate including at least one of alumina and zirconia.
Claim 30
Dependent Claim
17 words
The catalyst of claim 27, wherein the second catalyst layer further comprises a rare earth element oxide.
Claim 31
Dependent Claim
21 words
The catalyst of claim 9, wherein the monolith carrier has a honeycomb structure and is comprised of a heat-resistant inorganic material.
Claim 32
Dependent Claim
36 words
The catalyst of claim 9, wherein said monolith carrier comprises a honeycomb structure and at least one pair of electrodes electrically connected to said honeycomb structure, said monolith carrier being adapted to generate heat when electrified.
Claim 33
Dependent Claim
19 words
The catalyst of claim 30, wherein said monolith carrier further comprises a resistance adjusting means provided between the electrodes.
Claim 34
Dependent Claim
119 words
A catalyst for exhaust gas purification, comprising: at least one monolith carrier having an upstream portion and a downstream portion; a first catalyst layer having a hydrocarbon purification activity provided on said upstream portion of the monolith carrier, said first catalyst layer having an outermost portion comprising at least one of Pt and Pd as an active component; a second catalyst layer having a three-way catalytic activity provided on said downstream portion of the monolith carrier, said second catalyst layer comprising Rh as an active component; and a third catalyst layer provided on said second catalyst layer, said third catalyst layer having a hydrocarbon purification activity and comprising at least one of Pt and Pd as an active component.
Claim 35
Dependent Claim
119 words
A catalyst for exhaust gas purification, comprising: at least one monolith carrier having an upstream portion and a downstream portion; a first catalyst layer having a hydrocarbon purification activity provided on said upstream portion of the monolith carrier, said first catalyst layer having an outermost portion comprising at least one of Pt and Pd as an active component; a second catalyst layer having a three-way catalytic activity provided on said downstream portion of the monolith carrier, said second catalyst layer comprising Rh as an active component; and a third catalyst layer provided on said second catalyst layer, said third catalyst layer having a hydrocarbon purification activity and comprising at least one of Pt and Pd as an active component.
Claim 36
Dependent Claim
13 words
The catalyst of claim 32, wherein the first catalyst layer comprises mainly Pd.
Claim 37
Dependent Claim
13 words
The catalyst of claim 33, wherein the first catalyst layer consists of Pd.
Claim 38
Dependent Claim
36 words
The catalyst of claim 32, wherein the first catalyst layer comprises a plurality of sub-layers, including a first sub-layer, and a second sub-layer provided on said first sub-layer, said outermost portion consisting of said second sub-layer.
Claim 39
Dependent Claim
18 words
The catalyst of claim 35, wherein the second sub-layer contains said at least one of Pt and Pd.
Claim 40
Dependent Claim
13 words
The catalyst of claim 36, wherein the second sub-layer consists essentially of Pd.
Claim 41
Dependent Claim
11 words
The catalyst of claim 37, wherein the first sub-layer contains Rh.
Claim 42
Dependent Claim
13 words
The catalyst of claim 32, wherein the third catalyst layer comprises mainly Pd.
Claim 43
Dependent Claim
35 words
The catalyst of claim 32, wherein the second catalyst layer includes a plurality of sub-layers, including a first sub-layer containing at least one of Pd and Pt, and an outermost second sub-layer comprising mainly Rh.
Claim 44
Dependent Claim
40 words
The catalyst of claim 32, wherein the first catalyst layer further comprises Rh which is separated from said at least one of Pt and Pd to avoid contact between the Rh and said at least one of Pt and Pd.
Claim 45
Dependent Claim
49 words
The catalyst of claim 32, wherein the Rh of said second catalyst layer and the at Least one of Pt and Pd of the first and third catalyst layers are separated from each other to avoid contact between the Rh and the at least one of Pt and Pd.
Claim 46
Dependent Claim
45 words
The catalyst of claim 32, wherein the second catalyst layer further comprises at least one of Pt and Pd which is separated form the Rh of the second catalyst layer to avoid contact between the Rh and the at least one of Pt and Pd.
Claim 47
Dependent Claim
23 words
The catalyst of claim 32, wherein said first catalyst layer further comprises a substrate containing mainly at least one of alumina and zeolite.
Claim 48
Dependent Claim
11 words
The catalyst of claim 44, wherein the substrate further comprises zirconia.
Claim 49
Dependent Claim
17 words
The catalyst of claim 45, wherein the first catalyst layer further comprises a rare earth element oxide.
Claim 50
Dependent Claim
24 words
The catalyst of claim 32, wherein the second catalyst layer further comprises a substrate composed mainly of at least one of alumina and zirconia.
Claim 51
Dependent Claim
17 words
The catalyst of claim 47, wherein the second catalyst layer further comprises a rare earth element oxide.
Claim 52
Dependent Claim
21 words
The catalyst of claim 32, wherein the monolith carrier has a honeycomb structure and is comprised of a heat-resistant inorganic material.
Claim 53
Dependent Claim
36 words
The catalyst of claim 32, wherein the monolith carrier comprises a honeycomb structure and at least one pair of electrodes electrically connected to the honeycomb structure, said monolith carrier being adapted to generate heat when electrified.
Claim 54
Dependent Claim
25 words
The catalyst of claim 50, wherein said at least one monolith carrier comprises a plurality of monolith carriers which are electrically connected to each other.
Claim 55
Dependent Claim
18 words
The catalyst of claim 51, wherein a resistance-adjusting means is provided between the electrodes of each monolith carrier.
References Cited (Backward Citations)
US4099377A
Cited
US4183212A
Cited
US4170112A
Cited
US4448756A
Cited
JPS6384635A
Cited
JPH0256247A
Cited
JPH0372953A
Cited
EP0428752A1
Cited
JPH0338892A
Cited
JPH03101813A
Cited
US5010051A
Cited
EP0427494A2
Cited
EP0443765A1
Cited
EP0462593A1
Cited
EP0485180A1
Cited
EP0488716B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-12-26 | 1998-06-27 | 1998-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-26 | 2002-06-27 | 2002-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-26 | 2006-06-27 | 2006-12-27 | $7700.00 | Window Closed / Lapsed |