JP3311370B2 - Exhaust purification catalyst system - Google Patents
Exhaust purification catalyst systemInfo
- Publication number
- JP3311370B2 JP3311370B2 JP28923691A JP28923691A JP3311370B2 JP 3311370 B2 JP3311370 B2 JP 3311370B2 JP 28923691 A JP28923691 A JP 28923691A JP 28923691 A JP28923691 A JP 28923691A JP 3311370 B2 JP3311370 B2 JP 3311370B2
- Authority
- JP
- Japan
- Prior art keywords
- zeolite
- catalyst
- transition metal
- exhaust
- carrier
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000003054 catalyst Substances 0.000 title claims description 64
- 238000000746 purification Methods 0.000 title claims description 3
- 229910021536 Zeolite Inorganic materials 0.000 claims description 38
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 claims description 38
- 239000010457 zeolite Substances 0.000 claims description 38
- 229910052723 transition metal Inorganic materials 0.000 claims description 25
- 150000003624 transition metals Chemical class 0.000 claims description 25
- 229910052763 palladium Inorganic materials 0.000 claims description 22
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 21
- 229910052697 platinum Inorganic materials 0.000 claims description 15
- 229910052703 rhodium Inorganic materials 0.000 claims description 12
- 229910000510 noble metal Inorganic materials 0.000 claims description 8
- 238000011144 upstream manufacturing Methods 0.000 claims description 5
- 238000002485 combustion reaction Methods 0.000 claims description 4
- 239000010970 precious metal Substances 0.000 claims 1
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 28
- 239000007789 gas Substances 0.000 description 24
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 14
- 239000010948 rhodium Substances 0.000 description 12
- 239000010949 copper Substances 0.000 description 11
- 230000000694 effects Effects 0.000 description 6
- 239000002002 slurry Substances 0.000 description 6
- 239000000969 carrier Substances 0.000 description 4
- 238000010304 firing Methods 0.000 description 4
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 229910052878 cordierite Inorganic materials 0.000 description 3
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 229910017604 nitric acid Inorganic materials 0.000 description 3
- 239000008188 pellet Substances 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 230000005802 health problem Effects 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 210000002345 respiratory system Anatomy 0.000 description 2
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 2
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000001479 atomic absorption spectroscopy Methods 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 229910000420 cerium oxide Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- OPQARKPSCNTWTJ-UHFFFAOYSA-L copper(ii) acetate Chemical compound [Cu+2].CC([O-])=O.CC([O-])=O OPQARKPSCNTWTJ-UHFFFAOYSA-L 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000000241 respiratory effect Effects 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B3/00—Engines characterised by air compression and subsequent fuel addition
- F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
Landscapes
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は自動車等のエンジンから
排出される排気ガス中の窒素酸化物、特にＮＯ2 を低減
するための排気浄化用触媒システムに関する。The present invention relates to a nitrogen oxide in the exhaust gas discharged from an engine of an automobile or the like, relates to an exhaust purifying catalyst systems, particularly for reducing the NO 2.
【０００２】[0002]
【従来の技術】従来、自動車排気ガス中のＣＯ，ＨＣ，
ＮＯｘを浄化するため、いわゆる三元触媒が種々提案さ
れており、これらの触媒においては、ＮＯｘをＣＯ，Ｈ
2 やＨＣとの反応によってＮ2 に還元することが、その
効果の一つとして期待されている。2. Description of the Related Art Conventionally, CO, HC,
In order to purify NOx, various so-called three-way catalysts have been proposed. In these catalysts, NOx is converted into CO, H
Reduction to N 2 by reaction with 2 or HC is expected as one of the effects.
【０００３】[0003]
【発明が解決しようとする課題】しかし、高空燃比エン
ジン（リーン・バーン・ガソリンエンジン又はディーゼ
ル・エンジン）にこれらの触媒を用いた場合、排気ガス
中の酸素濃度が高いため、還元剤であるＣＯやＨＣが酸
素と優先的に反応してしまい、上記のようなＮＯｘのＮ
2 への還元は必ずしも容易ではない。However, when these catalysts are used in a high air-fuel ratio engine (lean burn gasoline engine or diesel engine), since the oxygen concentration in the exhaust gas is high, CO 2 is a reducing agent. And HC react preferentially with oxygen, and the NOx N
Reduction to 2 is not always easy.
【０００４】しかも、ＣＯやＨＣの浄化活性を高く維持
するため、これらの触媒をある程度以上の高温（例え
ば、３５０℃以上の温度）の排気ガス中で用いると、却
って排気ガス中の未反応のＮＯを酸化してＮＯ2 にして
しまい、ＮＯ2 排出量を増大させるという傾向のあるこ
とがわかって来た。Furthermore, if these catalysts are used in an exhaust gas at a high temperature of a certain degree or more (for example, a temperature of 350 ° C. or more) in order to maintain a high activity of purifying CO and HC, unreacted components in the exhaust gas will be recovered. It has been found that NO tends to be oxidized to NO 2 , resulting in an increase in NO 2 emission.
【０００５】そして、ＮＯ，ＮＯ2 その他のＮＯｘはい
ずれも悪影響を及ぼす物質であるが、そのうちＮＯ2 は
相対的に人体の呼吸器系への悪影響が強いと言われ、且
つ速効性であることが指摘されている。このため、幹線
道路周辺に高濃度のＮＯ2 を含む自動車排気ガスが排出
され、そのまま滞留するという事態を考えると、ＮＯ2
による沿道住民の呼吸器系の健康問題が他種ＮＯｘ汚染
問題よりも突出した優先解決課題としてクローズ・アッ
プされる可能性がある。例えば、公害対策基本法（昭和
42年法律第132 号）第９条の規定に基づく環境庁告示の
第38条ではＮＯｘのうちＮＯ2 を優先的に規制対象とし
ている。[0005] While NO, NO 2 and other NOx are all substances having an adverse effect, it is said that NO 2 has a relatively strong adverse effect on the respiratory system of the human body and that it is fast-acting. Has been pointed out. For this reason, considering a situation in which vehicle exhaust gas containing high-concentration NO 2 is emitted around a highway and stays as it is, NO 2
It is possible that the health problems of the respiratory system of roadside residents will be highlighted as a priority solution that is more prominent than other NOx pollution problems. For example, the Pollution Control Basic Law (Showa
In 1942 Law No. 132) Article 38 of notification of the Environment Agency under the provisions of Article 9 is set to preferentially regulated the NO 2 among of NOx.
【０００６】そこで本発明は、リーン・バーン・ガソリ
ンエンジン又はディーゼル・エンジンに三元触媒を用い
る場合におけるＮＯ2 沿道汚染低減のため、可及的に有
効な当面の対策を提供しようとするものである。[0006] Therefore, the present invention is to provide as soon as possible effective measures to reduce NO 2 roadside pollution when a three-way catalyst is used in a lean burn gasoline engine or a diesel engine. is there.
【０００７】[0007]
【課題を解決するための手段】上記の課題を解決するた
めの第１の手段は、内燃機関等の排気系における上流の
高排気温領域にＰｔ，Ｒｈ，Ｐｄの単成分又はそれらの
組合せからなる貴金属系触媒を配置するとともに、その
下流の低排気温領域に、ゼオライト系担体と該ゼオライ
ト系担体に担持されるＰｔ，Ｐｄ，Ｒｈの単成分又はそ
れらの組合せからなる遷移金属とからなる遷移金属／ゼ
オライト系触媒の１種又は２種以上を配置したことを特
徴とする排気浄化用触媒システムである。また、上記課
題を解決するための第２の手段は、内燃機関等の排気系
における上流の高排気温領域にＰｔ，Ｒｈ，Ｐｄの単成
分又はそれらの組合せからなる貴金属系触媒をもつ第１
容器を配置するとともに、その下流の低排気温領域に、
ゼオライト系担体と該ゼオライト系担体に担持されるＰ
ｔ，Ｐｄ，Ｃｕ，Ｒｈの単成分又はそれらの組合せから
なる遷移金属とからなる遷移金属／ゼオライト系触媒の
１種又は２種以上をもつ該第１容器と物理的に分離して
いる第２容器を配置したことを特徴とする排気浄化用触
媒システムである。 A first means for solving the above-mentioned problem is that a single component of Pt, Rh, and Pd or a combination thereof is provided in a high exhaust gas temperature region upstream in an exhaust system such as an internal combustion engine. And a zeolite-based support and the zeolite in a low exhaust temperature region downstream thereof.
Single component of Pt, Pd, Rh supported on
An exhaust gas purification catalyst system comprising one or more transition metal / zeolite catalysts comprising a transition metal comprising a combination thereof. Also, the above section
A second means for solving the problem is an exhaust system such as an internal combustion engine.
Of Pt, Rh and Pd in the high exhaust temperature region
No. 1 with a noble metal based catalyst consisting of
While placing the container, in the low exhaust temperature area downstream of it,
Zeolite-based carrier and P supported on the zeolite-based carrier
From a single component of t, Pd, Cu, Rh or a combination thereof
Transition metal / zeolite catalyst
Physically separated from the first container having one or more types
For purifying exhaust gas, wherein a second container is disposed.
It is a medium system.
【０００８】[0008]
【作用】リーン・バーン・エンジンからの排気ガスが、
排気系の上流の高排気温領域において貴金属系触媒で処
理されると、ＣＯ，ＨＣが浄化される一方で、排気ガス
中の未反応のＮＯがＮＯ2 に酸化される。[Action] The exhaust gas from the lean burn engine is
When treated with a noble metal catalyst in a high exhaust temperature region upstream of the exhaust system, CO and HC are purified, while unreacted NO in the exhaust gas is oxidized to NO 2 .
【０００９】次いで、このＮＯ2は下流の低排気温領域
において遷移金属／ゼオライト系触媒で処理されること
により、ＮＯに還元されてから排出される。 Next, this NO 2 is treated with a transition metal / zeolite catalyst in a low exhaust temperature region downstream.
Is reduced to NO and then discharged.
【００１０】幹線道路周辺地域で排出されたＮＯが大気
中においてＮＯ2 に酸化されるには一定の時間を必要と
し、酸化されるまでの間に大半のＮＯが自然拡散や風に
よる拡散作用により幹線道路周辺地域外へ移動する。こ
のため、ＮＯ2 による沿道住民の呼吸器系の健康問題は
軽減される。なお、ＮＯによる影響はＮＯ2 による場合
に比べてその性質が異なり、しかもより遅効性であると
考えられる。従って、幹線道路周辺地域に滞留中（拡散
するまでの間）のＮＯによる影響はＮＯ2 による場合よ
りも相対的に低減される。[0010] It takes a certain period of time to oxidize NO discharged in the area around the main road into NO 2 in the atmosphere, and most of the NO is diffused by natural diffusion or wind by the time it is oxidized. Move outside the area around the main road. Therefore, the respiratory health problem of the roadside residents due to NO 2 is reduced. The effect of NO is different from that of NO 2 in nature, and is considered to be more delayed. Therefore, the effect of NO in the residence highway region (until the diffusion) is relatively reduced than with NO 2.
【００１１】[0011]
【効果】本発明の排気浄化用触媒システムは、幹線道路
周辺地域におけるＮＯ2 沿道汚染を軽減することができ
る。The exhaust gas purifying catalyst system of the present invention can reduce NO 2 roadside pollution in the area around a main road.
【００１２】[0012]
【実施態様】次に本発明の実施態様を説明する。Next, embodiments of the present invention will be described.
【００１３】本発明において、「高排気温領域」とは、
触媒によるリーン・バーン・エンジン排気ガスの処理に
おいて、未反応のＮＯがＮＯ2 に酸化されてしまうよう
な排気ガス温度を示す排気系内の領域を言う。これを更
に具体的に例示すれば、排気ガスの温度が３５０℃程
度、又はこれを超えるような温度である排気系の上流領
域、あるいは排気系のうち排気マニホールドやその付近
の部分を挙げることができるが、これらに限定されるも
のではない。In the present invention, the “high exhaust temperature range”
In the treatment of lean burn engine exhaust gas with a catalyst, it refers to a region in the exhaust system that exhibits an exhaust gas temperature at which unreacted NO is oxidized to NO 2 . More specifically, the temperature of the exhaust gas may be about 350 ° C. or higher, or the upstream area of the exhaust system, or the exhaust system and the exhaust manifold or its vicinity. It is possible, but not limited to these.
【００１４】次に、「低排気温領域」とは、触媒による
リーン・バーン・エンジン排気ガスの処理において、上
記のような未反応ＮＯのＮＯ2への酸化が起こらないよ
うな排気ガス温度を示す排気系内の領域を言う。これを
更に具体的に例示すれば、排気ガスの温度が３００℃程
度、又はこれを下回るような温度である排気系の下流領
域を挙げることができるが、これに限定されるものでは
ない。これらの「高排気温領域」及び「低排気温領域」
を区画するために、貴金属系触媒を配置する第１容器
と、遷移金属／ゼオライト系触媒を配置しその第１容器
と物理的に分離している第２容器とをもつことができ
る。 The "low exhaust gas temperature range" is defined as an exhaust gas temperature at which unreacted NO is not oxidized to NO 2 during the treatment of lean burn engine exhaust gas with a catalyst. Refers to the area in the exhaust system shown. As a more specific example, there may be mentioned a downstream region of the exhaust system in which the temperature of the exhaust gas is about 300 ° C. or lower, but is not limited to this. These "high exhaust temperature area" and "low exhaust temperature area"
First container in which a noble metal-based catalyst is placed in order to partition
And a first container in which a transition metal / zeolite catalyst is arranged
And a second container that is physically separated.
You.
【００１５】「貴金属系触媒」とは、アルミナ系の担体
にＰｔ若しくはＰｄのみを、又はＰｔとＲｈ（ロジウ
ム）若しくはＰｄとＲｈとを担持させた触媒を言う。Ｐ
ｔとＲｈ若しくはＰｄとＲｈを共に担持させた触媒にお
いては、両者を混在状態で担持させたものや、いわゆる
２ステージの状態で担持させたものを含む。担体はハニ
カム構造等のモノリス担体でも良く、ペレット状等の粉
粒状のものを用いても良い。担体に対するＰｔ／Ｒｈ又
はＰｄ／Ｒｈの担持量は特に限定しない。貴金属系触媒
は酸化セリウム（ＣｅＯ2 ）を含んでいても良い。The "noble metal catalyst" refers to a catalyst in which only Pt or Pd, or Pt and Rh (rhodium) or Pd and Rh is supported on an alumina carrier. P
The catalyst in which both t and Rh or Pd and Rh are supported includes a catalyst in which both are supported in a mixed state and a catalyst in which both are supported in a so-called two-stage state. The carrier may be a monolith carrier having a honeycomb structure or the like, or may be a powdery or granular one such as a pellet. The amount of Pt / Rh or Pd / Rh supported on the carrier is not particularly limited. The noble metal-based catalyst may include cerium oxide (CeO 2 ).
【００１６】次に、「遷移金属／ゼオライト系触媒」と
は、ゼオライト系の担体に遷移金属を担持させた触媒を
言う。さらに、下流の低排気温領域には、遷移金属／ア
ルミナ系触媒を混在することができる。ここで、「遷移
金属／アルミナ系触媒」とは、アルミナ系の担体に遷移
金属を担持させた触媒を言う。又、これらにおいて遷移
金属の種類は、Ｐｔ，Ｐｄ（パラジウム）及びＲｈが採
用できる。Ｐｔ及びＰｄがコストの点でとりわけ望まし
い。又、第１容器と、その第１容器と物理的に分離して
いる第２容器とを用いた触媒装置における遷移金属の種
類として、前述したＰｔ，Ｐｄ（パラジウム）及びＲｈ
に加えて更に、Ｃｕ（銅）が採用できる。この中でもＰ
ｔ，Ｐｄ（パラジウム），Ｃｕ（銅）がコストの点でと
りわけ望ましい。 Next, "transition metal / zeolite catalyst" refers to a catalyst in which a transition metal is supported on a zeolite carrier. Furthermore, a transition metal / alumina-based catalyst can be mixed in the downstream low exhaust temperature region. Here, the “transition metal / alumina catalyst” refers to a catalyst in which a transition metal is supported on an alumina carrier. In these, types of transition metals include Pt, Pd (palladium) and Rh.
Can be used. Pt and Pd are particularly desirable in terms of cost
No. In addition, the first container is physically separated from the first container.
Of transition metal in a catalytic device using a second container
Pt, Pd (palladium) and Rh
In addition, Cu (copper) can be adopted. Among them, P
t, Pd (palladium), Cu (copper) in terms of cost
Especially desirable.
【００１７】上記の遷移金属／ゼオライト系触媒とし
て、例えば、次の〜の触媒の１種又は２種以上を使
用することができる。そして、及び／又はの触媒を
混在して用いることもできる。 Ｐｔ／ゼオライト触媒 Ｐｄ／ゼオライト触媒 Ｃｕ／ゼオライト触媒 Ｐｄ／アルミナ触媒 Ｐｔ／アルミナ触媒 As the above transition metal / zeolite catalyst, for example, one or more of the following catalysts can be used. And / or the catalyst
They can be used in combination. Pt / zeolite catalyst Pd / zeolite catalyst Cu / zeolite catalyst Pd / alumina catalyst Pt / alumina catalyst
【００１８】上記の遷移金属／アルミナ系触媒又は遷移
金属／ゼオライト系触媒において、アルミナ系又はゼオ
ライト系の担体は、その種類を限定しない。これらの担
体はハニカム構造等のモノリス担体でも良く、ペレット
状のものを用いても良い。担体に対するＰｔ，Ｐｄ，Ｃ
ｕ等の担持量は特に限定しない。In the above transition metal / alumina catalyst or transition metal / zeolite catalyst, the type of the alumina or zeolite carrier is not limited. These carriers may be monolith carriers having a honeycomb structure or the like, or may be pellets. Pt, Pd, C for carrier
The carrying amount of u and the like is not particularly limited.
【００１９】遷移金属／アルミナ系触媒又は遷移金属／
ゼオライト系触媒の２種以上を使用する場合、それらを
ペレット状の形態で混在状態で使用したり、あるいは同
一の担体上に混在状態又はいわゆる２ステージの状態で
担持させたりすることができる。Transition metal / alumina catalyst or transition metal /
When two or more zeolite-based catalysts are used, they can be used in a mixed state in the form of pellets, or can be supported on the same carrier in a mixed state or a so-called two-stage state.
【００２０】[0020]
【実施例】次に本発明の実施例を説明する。Next, embodiments of the present invention will be described.
【００２１】〔Ｐｄ／アルミナ触媒，Ｐｔ／アルミナ触
媒の調製〕アルミナ１００重量部と市販の硝酸アルミニ
ウム水溶液１４重量部とを水及び硝酸と共にボールミリ
ングすることによりウオッシュコートスラリーを生成さ
せた。そして断面積１平方インチ当たり約４００の流路
を含む１．３リッターのコーディエライトの一体性担体
をウオッシュコートスラリー中に浸漬した。続いて圧縮
空気で一体性担体のセル内の過剰液を吹き去り、この一
体性担体を乾燥し、７００℃で１時間焼成して、一体性
担体上に約５０ミクロンのアルミナをコートした。[Preparation of Pd / alumina catalyst and Pt / alumina catalyst] A wash coat slurry was produced by ball milling 100 parts by weight of alumina and 14 parts by weight of a commercially available aqueous solution of aluminum nitrate together with water and nitric acid. Then 1.3 liters of cordierite integral carrier containing about 400 channels per square inch of cross-sectional area was immersed in the washcoat slurry. Subsequently, the excess liquid in the cells of the integral carrier was blown off with compressed air, and the integral carrier was dried and baked at 700 ° C. for 1 hour to coat about 50 μm of alumina on the integral carrier.
【００２２】次に２個の上記一体性担体をそれぞれ所定
濃度のジニトロジアミンパラジウム及びジニトロジアミ
ン白金の硝酸酸性水溶液に各々浸漬し、乾燥後、２００
℃で１時間焼成して２．０ｇ／リッターのパラジウム並
びに白金を担持させた。Next, the two integrated carriers are immersed in aqueous solutions of dinitrodiamine palladium and dinitrodiamineplatinum in a predetermined concentration of nitric acid.
Calcination was carried out at a temperature of 1 ° C. for 1 hour to carry 2.0 g / liter of palladium and platinum.
【００２３】〔Ｐｄ／ゼオライト触媒，Ｐｔ／ゼオライ
ト触媒の調製〕Ｓｉ（シリカ）／Ａｌ（アルミニウム）
比が４０のＮａ型ＺＳＭ−５ゼオライト粉末１００重量
部、シリカゾル（ＳｉＯ2 ２０重量％）７０重量部、純
水８０重量部を混合攪拌し、スラリーを調整した。そし
て断面積１平方インチ当たり約４００の流路を含む１．
３リッターのコーディエライトの一体性担体をウオッシ
ュコートスラリー中に浸漬した。続いて圧縮空気で一体
性担体のセル内の過剰液を吹き去った後、１００℃で３
時間乾燥して３００℃で２時間焼成する操作を２回繰り
返し、更に５００℃で３時間焼成して一体性担体上にゼ
オライト層を形成した。このゼオライト層は、ハニカム
担体１リッター当たり１２０±５ｇ形成されている。[Preparation of Pd / zeolite catalyst, Pt / zeolite catalyst] Si (silica) / Al (aluminum)
A slurry was prepared by mixing and stirring 100 parts by weight of Na type ZSM-5 zeolite powder having a ratio of 40, 70 parts by weight of silica sol (20% by weight of SiO 2 ), and 80 parts by weight of pure water. And including about 400 channels per square inch of cross section1.
Three liters of cordierite integral carrier were immersed in the washcoat slurry. Subsequently, excess liquid in the cells of the integrated carrier was blown off with compressed air,
An operation of drying for 2 hours and firing at 300 ° C. for 2 hours was repeated twice, and further firing at 500 ° C. for 3 hours to form a zeolite layer on the integral carrier. The zeolite layer is formed in an amount of 120 ± 5 g per liter of the honeycomb carrier.
【００２４】上記ゼオライト層を持つ２個のハニカム担
体をそれぞれ所定濃度のジニトロジアミンパラジウム及
びジニトロジアミン白金の水溶液に２４時間浸漬し、引
き上げて余分な溶液を吹き払った後２５０℃で１時間焼
成した。得られた触媒を原子吸光分析により分析したと
ころ、触媒１リッター当たり１．７３ｇ、即ちゼオライ
ト層に対して１．４４重量％のＰｄ又はＰｔが担持され
ていた。Each of the two honeycomb carriers having the zeolite layer was immersed in an aqueous solution of dinitrodiaminepalladium and dinitrodiamineplatinum of a predetermined concentration for 24 hours, pulled up and blown off an excess solution, and then calcined at 250 ° C. for 1 hour. . The obtained catalyst was analyzed by atomic absorption spectroscopy. As a result, it was found that 1.73 g of Pd or Pt was supported per liter of the catalyst, that is, 1.44% by weight of the zeolite layer.
【００２５】〔Ｃｕ／ゼオライト触媒の調製〕Ｓｉ／Ａ
ｌ比が４０のＮａ型ＺＳＭ−５ゼオライト粉末１００重
量部を酢酸銅水溶液（濃度０．０４モル／リッター）
２，０００重量部中に数日間静置した後、取り出して乾
燥し、Ｃｕをイオン交換したゼオライトを得た。次に、
上記Ｃｕ／ゼオライト触媒１００重量部、シリカゾル
（ＳｉＯ2 ２０重量％）７０重量部、純水８０重量部を
混合攪拌し、ｐＨが３〜６の範囲となるように硝酸を加
えスラリーを調整した。そして断面積１平方インチ当た
り約４００の流路を含む１．３リッターのコーディエラ
イトの一体性担体をウオッシュコートスラリー中に浸漬
した。続いて圧縮空気で一体性担体のセル内の過剰液を
吹き去った後、１００℃で３時間乾燥して３００℃で２
時間焼成する操作を２回繰り返し、更に５００℃で３時
間焼成して一体性担体上にＣｕ／ゼオライト触媒層を形
成した。このＣｕ／ゼオライト触媒のＣｕのイオン交換
率は１０５％であった。[Preparation of Cu / zeolite catalyst] Si / A
100 parts by weight of Na type ZSM-5 zeolite powder having a 1 ratio of 40 was added to an aqueous copper acetate solution (concentration: 0.04 mol / liter)
After leaving still in 2,000 parts by weight for several days, it was taken out and dried to obtain a zeolite in which Cu was ion-exchanged. next,
The Cu / zeolite catalyst 100 parts by weight, silica sol (SiO 2 20 wt%) 70 parts by weight of pure water 80 parts by weight were mixed and stirred, pH was adjusted slurry was added nitric acid so that the range of 3-6. Then 1.3 liters of cordierite integral carrier containing about 400 channels per square inch of cross-sectional area was immersed in the washcoat slurry. Subsequently, the excess liquid in the cell of the integrated carrier was blown off with compressed air, dried at 100 ° C. for 3 hours, and dried at 300 ° C. for 2 hours.
The operation of firing for 2 hours was repeated twice, and the firing was further performed at 500 ° C. for 3 hours to form a Cu / zeolite catalyst layer on the integrated support. The Cu ion exchange rate of this Cu / zeolite catalyst was 105%.
【００２６】〔実験例〕図１のエンジン１において、排
気マニホールド２付近の接合部３に貴金属系触媒を配置
し、次に下流側の第１容器部４に前記〜の遷移金属
／アルミナ系触媒又は遷移金属／ゼオライト系触媒のい
ずれか一をそれぞれ配置した。これらをそれぞれ実験例
１〜実験例５と称する。[Experimental Example] In the engine 1 of FIG. 1, a noble metal-based catalyst is disposed at the joint 3 near the exhaust manifold 2, and then the above-mentioned transition metal / alumina-based catalyst is placed in the first container 4 on the downstream side. Alternatively, one of the transition metal / zeolite catalysts was disposed. These are referred to as Experimental Examples 1 to 5, respectively.
【００２７】実験例１〜実験例５においてエンジン１は
排気量２リッターであり、これをＡ／Ｆ＝２０、１，２
００ｒｐｍ、４０Ｎｍで運転した。その際、接合部３の
入りガス温度は４００℃、出ガスのＮＯ濃度は６００ｐ
ｐｍ、ＮＯ2濃度は４００ｐｐｍであり、第１容器部４
の入りガス温度は２５０℃であった。In Experimental Examples 1 to 5, the engine 1 had a displacement of 2 liters, which was A / F = 20, 1, 2
The operation was performed at 00 rpm and 40 Nm. At that time, the inlet gas temperature of the joint 3 was 400 ° C., and the NO concentration of the outlet gas was 600 p.
pm, NO 2 concentration is 400 ppm,
Was 250 ° C.
【００２８】以上のような実験例１〜実験例５における
第１容器部４の出ガスのＮＯ濃度，ＮＯ2濃度及びＮＯ2
／ＮＯ比は表１の通りであり、各実験例において排気中
のＮＯ2のかなりの部分がＮＯに還元されていることが
分かる。特に本発明の触媒である実験例３〜５の触媒に
おけるＮＯ 2 濃度及びＮＯ 2 ／ＮＯ比は、従来技術である
実験例１、２の値と比較して大幅に低下している。 The NO concentration, NO 2 concentration, and NO 2 concentration of the gas discharged from the first container portion 4 in Experimental Examples 1 to 5 as described above.
The / NO ratio is as shown in Table 1, and it can be seen that a considerable portion of the NO 2 in the exhaust gas was reduced to NO in each experimental example. Particularly, the catalysts of Experimental Examples 3 to 5, which are the catalysts of the present invention,
NO 2 concentration and NO 2 / NO ratio are prior art
It is significantly lower than the values of Experimental Examples 1 and 2.
【００２９】[0029]
【表１】 [Table 1]
【００３０】なお、図１のようなエンジンを用いる場合
において、その運転条件によって第１容器部４でも入り
ガス温度が十分に高く（例えば４００℃程度）、且つそ
の下流側の第２容器部５での入りガス温度が低い（例え
ば２５０℃程度）場合には、第１容器部４に貴金属系触
媒を配置し、且つ第２容器部５に遷移金属／ゼオライト
系触媒を配置することもできる。 When the engine as shown in FIG. 1 is used, the gas temperature in the first container section 4 is sufficiently high (for example, about 400 ° C.) and the second container section 5 on the downstream side depends on the operating conditions. When the temperature of the incoming gas is low (for example, about 250 ° C.), a noble metal catalyst is disposed in the first container part 4 and the transition metal / zeolite is stored in the second container part 5.
A system catalyst can also be arranged.
【図面の簡単な説明】[Brief description of the drawings]
【図１】本発明の実験例の構成を模式的に示すものであ
る。FIG. 1 schematically shows a configuration of an experimental example of the present invention.
１・・・エンジン ２・・・排気マニホールド ３・・・接合部 ４・・・第１容器部 ５・・・第２容器部 DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Exhaust manifold 3 ... Joint part 4 ... 1st container part 5 ... 2nd container part
───────────────────────────────────────────────────── フロントページの続き (72)発明者 加藤 健治 愛知県豊田市トヨタ町１番地 トヨタ自 動車株式会社内 (72)発明者 木原 哲郎 愛知県豊田市トヨタ町１番地 トヨタ自 動車株式会社内 (56)参考文献 特開 昭56−110507（ＪＰ，Ａ) 特開 昭62−106844（ＪＰ，Ａ) 特開 昭62−106842（ＪＰ，Ａ) 特開 平５−7737（ＪＰ，Ａ) 特開 平５−68887（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) B01D 53/94 B01J 21/00 - 38/74 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenji Kato 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Tetsuro Kihara 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation ( 56) References JP-A-56-110507 (JP, A) JP-A-62-106844 (JP, A) JP-A-62-106842 (JP, A) JP-A-5-7737 (JP, A) JP Hei 5-68887 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) B01D 53/94 B01J 21/00-38/74
Claims (2)
気温領域にＰｔ，Ｒｈ，Ｐｄの単成分又はそれらの組合
せからなる貴金属系触媒を配置するとともに、その下流
の低排気温領域に、ゼオライト系担体と該ゼオライト系
担体に担持されるＰｔ，Ｐｄ，Ｒｈの単成分又はそれら
の組合せからなる遷移金属とからなる遷移金属／ゼオラ
イト系触媒の１種又は２種以上を配置したことを特徴と
する排気浄化用触媒システム。1. A noble metal catalyst composed of a single component of Pt, Rh, and Pd or a combination thereof is disposed in a high exhaust temperature region upstream of an exhaust system such as an internal combustion engine, and in a low exhaust temperature region downstream thereof . Zeolite-based carrier and the zeolite-based
Single component of Pt, Pd, Rh supported on a carrier or
An exhaust gas purifying catalyst system, wherein one or two or more transition metal / zeolite-based catalysts comprising a combination of a transition metal and a combination of the above-mentioned transition metals are arranged.
気温領域にＰｔ，Ｒｈ，Ｐｄの単成分又はそれらの組合Single component of Pt, Rh, Pd or their combination in temperature range
せからなる貴金属系触媒をもつ第１容器を配置するととTo place a first vessel with a precious metal catalyst
もに、その下流の低排気温領域に、ゼオライト系担体とIn addition, a zeolite-based carrier is
該ゼオライト系担体に担持されるＰｔ，Ｐｄ，Ｃｕ，ＲPt, Pd, Cu, R supported on the zeolite-based support
ｈの単成分又はそれらの組合せからなる遷移金属とからand a transition metal consisting of a single component of h or a combination thereof.
なる遷移金属／ゼオライト系触媒の１種又は２種以上をOne or more transition metal / zeolite catalysts
もつ該第１容器と物理的に分離している第２容器を配置A second container that is physically separated from the first container
したことを特徴とする排気浄化用触媒システム。An exhaust purification catalyst system characterized by the following.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28923691A JP3311370B2 (en) | 1991-10-07 | 1991-10-07 | Exhaust purification catalyst system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28923691A JP3311370B2 (en) | 1991-10-07 | 1991-10-07 | Exhaust purification catalyst system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0596132A JPH0596132A (en) | 1993-04-20 |
| JP3311370B2 true JP3311370B2 (en) | 2002-08-05 |
Family
ID=17740549
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28923691A Expired - Fee Related JP3311370B2 (en) | 1991-10-07 | 1991-10-07 | Exhaust purification catalyst system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3311370B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08103656A (en) | 1994-10-06 | 1996-04-23 | N E Chemcat Corp | Catalyst for purification of exhaust gas and method therefor |
| WO2004094045A1 (en) | 2003-04-17 | 2004-11-04 | Johnson Matthey Public Limited Company | Method of decomposing nitrogen dioxide |
-
1991
- 1991-10-07 JP JP28923691A patent/JP3311370B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0596132A (en) | 1993-04-20 |
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