JPH0422707A - Catalyst converter - Google Patents
Catalyst converterInfo
- Publication number
- JPH0422707A JPH0422707A JP2125165A JP12516590A JPH0422707A JP H0422707 A JPH0422707 A JP H0422707A JP 2125165 A JP2125165 A JP 2125165A JP 12516590 A JP12516590 A JP 12516590A JP H0422707 A JPH0422707 A JP H0422707A
- Authority
- JP
- Japan
- Prior art keywords
- bearer
- metal
- catalyst
- coat layer
- exhaust gas
- 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.)
- Pending
Links
- 239000003054 catalyst Substances 0.000 title abstract description 9
- 229910052751 metal Inorganic materials 0.000 claims abstract description 27
- 239000002184 metal Substances 0.000 claims abstract description 27
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical group O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 claims abstract description 12
- 229910000510 noble metal Inorganic materials 0.000 claims abstract description 11
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 8
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 8
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 7
- 230000003197 catalytic effect Effects 0.000 claims description 17
- 239000000446 fuel Substances 0.000 abstract description 16
- 239000000203 mixture Substances 0.000 abstract description 12
- 230000004308 accommodation Effects 0.000 abstract 1
- 238000000746 purification Methods 0.000 description 8
- 239000010410 layer Substances 0.000 description 4
- 230000001052 transient effect Effects 0.000 description 4
- 230000001133 acceleration Effects 0.000 description 2
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
- F01N3/28—Construction of catalytic reactors
- F01N3/2803—Construction of catalytic reactors characterised by structure, by material or by manufacturing of catalyst support
- F01N3/2825—Ceramics
- F01N3/2828—Ceramic multi-channel monoliths, e.g. honeycombs
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Ceramic Engineering (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Exhaust Gas After Treatment (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
Description
【発明の詳細な説明】
[発明の目的]
(産業上の利用分野)
本発明は希薄混合気あるいは理論空燃比の混合気が燃焼
されるエンジンから排出されるNOxの浄化効率をいず
れも高めることができる触媒コンバータに関する。[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention aims to improve the purification efficiency of NOx emitted from an engine in which a lean mixture or a mixture at a stoichiometric air-fuel ratio is burned. Regarding catalytic converters that can
(従来の技術)
エンジンの燃料消費率を向上させるための1つの方法と
して、希薄混合気をエンジンで燃焼させることが知られ
ている。このようなエンジンをリーンバーンエンジンと
いう。このようなリーンバーンエンジンから排出される
NOxを分解する触媒として第5図に示す浄化効率特性
曲線を有するCu/ゼオライト構造を有するリーンNO
x触媒が用いられていた。なお、Cu/ゼオライト構造
とはゼオライト構造というAI、Siよりなる結晶構造
にCuを担持した構造をいう。(Prior Art) It is known that one method for improving the fuel consumption rate of an engine is to burn a lean air-fuel mixture in the engine. This kind of engine is called a lean burn engine. As a catalyst for decomposing NOx emitted from such a lean burn engine, lean NOx having a Cu/zeolite structure having a purification efficiency characteristic curve shown in Fig. 5 is used.
x catalyst was used. Note that the Cu/zeolite structure refers to a structure in which Cu is supported on a crystalline structure made of AI and Si, called a zeolite structure.
(発明が解決しようとする課題)
ところで、上記リーンバーンエンジンは定常運転時にお
いて希薄混合気をエンジンで燃焼させ、加速時等の過渡
運転時には理論空燃比の混合気をエンジンで燃焼させて
いる。(Problems to be Solved by the Invention) Incidentally, in the lean burn engine, the engine burns a lean air-fuel mixture during steady operation, and burns an air-fuel mixture at a stoichiometric air-fuel ratio during transient operation such as during acceleration.
しかし、従来のリーンNOx触媒をリーンバーンエンジ
ンの排気ガス浄化に用いた場合、加速時等の過渡運転時
に理論空燃比の混合気をエンジンで燃焼させるため、理
論空燃比付近で大量に排出されるNO,を完全に浄化す
ることはできなかった。これは、第5図に示すように、
従来のリーンNOx触媒のNOx浄化効率は理論空燃比
近傍では50%程度であるためである。However, when a conventional lean NOx catalyst is used to purify the exhaust gas of a lean burn engine, the engine burns the air-fuel mixture at the stoichiometric air-fuel ratio during transient operations such as during acceleration, resulting in large amounts of emissions near the stoichiometric air-fuel ratio. It was not possible to completely purify NO. This is as shown in Figure 5.
This is because the NOx purification efficiency of the conventional lean NOx catalyst is about 50% near the stoichiometric air-fuel ratio.
本発明は上記の点に鑑みてなされたもので、その目的は
希薄混合気あるいは理論空燃比の混合気が燃焼されたエ
ンジンから排出されるNOxの浄化効率をいずれも高め
ることができる触媒コンバータを提供することにある。The present invention has been made in view of the above points, and its purpose is to provide a catalytic converter that can improve the purification efficiency of NOx emitted from an engine that burns a lean mixture or a mixture at a stoichiometric air-fuel ratio. It is about providing.
[発明の構成]
(課題を解決するための手段)
メタル担体上に直接Pt、Rh、Pd等の貴金属元素を
単一若しくは複数担持させ、上記メタル担体の少なくと
も前側にCu/ゼオライト構造よりなるウォッシュコー
ト層を形成したことを特徴とする触媒コンバータである
。[Structure of the Invention] (Means for Solving the Problems) Single or multiple noble metal elements such as Pt, Rh, and Pd are directly supported on a metal carrier, and a wash having a Cu/zeolite structure is provided at least on the front side of the metal carrier. This is a catalytic converter characterized by forming a coating layer.
(作用)
リーンバーンエンジンの定常運転時に排出されるN O
xはウォッシュコート層のCu/ゼオライト構造の活性
点で分解促進され、理論空燃比で運転される過渡運転時
では、エンジンから排出さt’LるHc、CO,NOx
をメタル担体に直接担持されたPt、Rh、Pd等の貴
金属元素の活性点で、同時に低減させるようにしている
。(Function) NO emitted during steady operation of a lean burn engine
x is decomposed at the active sites of the Cu/zeolite structure of the washcoat layer, and during transient operation at the stoichiometric air-fuel ratio, the engine exhausts Hc, CO, and NOx.
is simultaneously reduced by the active sites of noble metal elements such as Pt, Rh, and Pd directly supported on the metal carrier.
(実施例)
以下図面を参照して本発明の一実施例に係わる触媒コン
バータについて説明する。第1図は後側のメタル担体上
への担持状態を示す断面図、第2図は前側のメタル担体
上への担持状態を示す断面図、第3図は触媒コンバータ
の軸方向に沿った断面図、第4図は触媒コンバータの径
方向に沿った断面図である。(Example) A catalytic converter according to an example of the present invention will be described below with reference to the drawings. Figure 1 is a cross-sectional view showing how it is supported on the rear metal carrier, Figure 2 is a cross-sectional view showing how it is supported on the front metal carrier, and Figure 3 is a cross-section taken along the axial direction of the catalytic converter. 4 are sectional views taken along the radial direction of the catalytic converter.
まず、第3図において、11は触媒コンバータである。First, in FIG. 3, 11 is a catalytic converter.
この触媒コンバータ11は断面が円筒形をしており、そ
の外周は排気ガスが流入される吸入部12、触媒が収納
される容器部13、浄化された排気ガスが排出される吐
出部14により構成される。This catalytic converter 11 has a cylindrical cross section, and its outer periphery is composed of an intake section 12 into which exhaust gas flows, a container section 13 where a catalyst is housed, and a discharge section 14 from which purified exhaust gas is discharged. be done.
さらに、15はハニカム形状を有するメタル担体である
。上記メタル担体15の前側(1部分)の構造について
は第1図を、上記メタル担体15の後側(■部分)の構
造については第2図を参照して後述する。そして、メタ
ル担体15により4方向か囲まれたセル16が軸方向に
無数に形成されている。Furthermore, 15 is a metal carrier having a honeycomb shape. The structure of the front side (one part) of the metal carrier 15 will be described later with reference to FIG. 1, and the structure of the rear side (■ part) of the metal carrier 15 will be described later with reference to FIG. Innumerable cells 16 surrounded by the metal carrier 15 in four directions are formed in the axial direction.
そして、上記メタル担体15上の構造について第1図及
び第2図を参照して説明する。まず、メタル担体15の
前側(1部分)は第1図に示すように、メタル担体15
上に直接Pt、Rh、Pdの貴金属が複数担持されてい
る。そして、このメタル担体15上にCu/ゼオライト
構造よりなるウォッシュコート層22が形成されている
。The structure on the metal carrier 15 will be explained with reference to FIGS. 1 and 2. First, as shown in FIG. 1, the front side (one part) of the metal carrier 15 is
A plurality of noble metals such as Pt, Rh, and Pd are directly supported on the surface. A wash coat layer 22 having a Cu/zeolite structure is formed on the metal carrier 15.
また、メタル担体15の後側(■部分)は第21図に示
すように、直接Pt、Rh、Pdの貴金属が複数担持さ
れている。Further, as shown in FIG. 21, a plurality of noble metals such as Pt, Rh, and Pd are directly supported on the rear side (■ part) of the metal carrier 15.
上記のように構成された触媒コンバータを用いることに
より、リーンバーンエンジンの定常運転時に排出される
NOXはウォッシュコート層22のCu/ゼオライト構
造の活性点で分解促進され、理論空燃比で運転される過
渡運転時では、エンジンから排出されるHC,Co、N
OXをメタル担体15に直接担持されたPt、Rh、P
d等の貴金属元素の活性点で、同時に低減させるように
している。つまり、本発明の一実施例に係わる触媒コン
バータのNOX浄化効率は第5図の実線で示すようにな
る。By using the catalytic converter configured as described above, the NOx emitted during steady operation of the lean burn engine is accelerated in decomposition at the active sites of the Cu/zeolite structure of the washcoat layer 22, and the engine is operated at the stoichiometric air-fuel ratio. During transient operation, HC, Co, and N discharged from the engine
Pt, Rh, P with OX directly supported on the metal carrier 15
At the same time, the active sites of noble metal elements such as d are reduced. In other words, the NOx purification efficiency of the catalytic converter according to one embodiment of the present invention is as shown by the solid line in FIG.
このように、メタル担体15の前側にCu/ゼオライト
構造を形成させることにより、Cu/ゼオライト活性点
付近での還元剤(H2、HC等)を確保し、NOXの浄
化効率を向上させることができる。In this way, by forming the Cu/zeolite structure on the front side of the metal carrier 15, it is possible to secure the reducing agent (H2, HC, etc.) near the Cu/zeolite active site and improve the NOX purification efficiency. .
なお、上記実施例ではメタル担体15に直接Pt R
h Pd等の貴金属元素を複数担持するようにしたが
、それらのうち単一の貴金属元素を担持するようにして
も良い。In the above embodiment, PtR was directly applied to the metal carrier 15.
Although a plurality of noble metal elements such as h Pd are supported, a single noble metal element may be supported.
[発明の効果]
以上詳述したように本発明によれば、希薄混合気あるい
は理論空燃比の混合気で燃焼されたエンジンから排出さ
れるNOXの浄化効率をいずれも高めることができる触
媒コンバータを提供することができる。[Effects of the Invention] As detailed above, the present invention provides a catalytic converter that can improve the purification efficiency of NOx emitted from an engine burned with a lean mixture or a mixture with a stoichiometric air-fuel ratio. can be provided.
第1図は本発明の一実施例に係わる触媒コンバータの前
側のメタル担体上への担持状態を示す断面図、第2図は
後側のメタル担体上への担持状態を示す断面図、第3図
は触媒コンバータの軸方向に沿った断面図、第4図は触
媒コンバータの径方向に沿った断面図、第5図はNOx
浄化効率と空燃比との関係を示す特性図である。
ニド・・触媒コンバータ、15・・・メタル担体、22
・・・ウォッシュコート層。FIG. 1 is a sectional view showing how a catalytic converter according to an embodiment of the present invention is supported on a metal carrier on the front side, FIG. 2 is a sectional view showing how it is supported on a metal carrier on the rear side, and FIG. The figure is a cross-sectional view along the axial direction of the catalytic converter, Figure 4 is a cross-sectional view along the radial direction of the catalytic converter, and Figure 5 is a cross-sectional view of the catalytic converter along the radial direction.
FIG. 2 is a characteristic diagram showing the relationship between purification efficiency and air-fuel ratio. Nido...Catalytic converter, 15...Metal carrier, 22
...Wash coat layer.
Claims (1)
を単一若しくは複数担持させ、上記メタル担体の少なく
とも前側にCu/ゼオライト構造よりなるウオッシュコ
ート層を形成したことを特徴とする触媒コンバータ。A catalytic converter characterized in that a single or multiple noble metal elements such as Pt, Rh, and Pd are supported directly on a metal carrier, and a wash coat layer having a Cu/zeolite structure is formed at least on the front side of the metal carrier.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2125165A JPH0422707A (en) | 1990-05-15 | 1990-05-15 | Catalyst converter |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2125165A JPH0422707A (en) | 1990-05-15 | 1990-05-15 | Catalyst converter |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0422707A true JPH0422707A (en) | 1992-01-27 |
Family
ID=14903493
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2125165A Pending JPH0422707A (en) | 1990-05-15 | 1990-05-15 | Catalyst converter |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0422707A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20040002344A (en) * | 2002-09-06 | 2004-01-07 | 안호근 | The catalyst for selective catalytic reduction of NOx |
US8652429B2 (en) | 2011-10-06 | 2014-02-18 | Johnson Matthey Public Limited Company | Oxidation catalyst for internal combustion engine exhaust gas treatment |
US8667785B2 (en) | 2011-12-12 | 2014-03-11 | Johnson Matthey Public Limited Company | Catalysed substrate monolith |
US8668891B2 (en) | 2011-12-12 | 2014-03-11 | Johnson Matthey Public Limited Company | Exhaust system for a lean-burn IC engine comprising a PGM component and a SCR catalyst |
CN113210010A (en) * | 2021-05-24 | 2021-08-06 | 无锡威孚环保催化剂有限公司 | VOC catalyst coated in different areas and preparation method thereof |
-
1990
- 1990-05-15 JP JP2125165A patent/JPH0422707A/en active Pending
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20040002344A (en) * | 2002-09-06 | 2004-01-07 | 안호근 | The catalyst for selective catalytic reduction of NOx |
US8652429B2 (en) | 2011-10-06 | 2014-02-18 | Johnson Matthey Public Limited Company | Oxidation catalyst for internal combustion engine exhaust gas treatment |
US9868115B2 (en) | 2011-10-06 | 2018-01-16 | Johnson Matthey Public Limited Company | Oxidation catalyst for internal combustion engine exhaust gas treatment |
US8667785B2 (en) | 2011-12-12 | 2014-03-11 | Johnson Matthey Public Limited Company | Catalysed substrate monolith |
US8668891B2 (en) | 2011-12-12 | 2014-03-11 | Johnson Matthey Public Limited Company | Exhaust system for a lean-burn IC engine comprising a PGM component and a SCR catalyst |
CN113210010A (en) * | 2021-05-24 | 2021-08-06 | 无锡威孚环保催化剂有限公司 | VOC catalyst coated in different areas and preparation method thereof |
CN113210010B (en) * | 2021-05-24 | 2023-09-19 | 无锡威孚环保催化剂有限公司 | VOC catalyst coated in different areas and preparation method thereof |
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