JPH10244167A - Catalyst structure body for purifying exhaust gas - Google Patents
Catalyst structure body for purifying exhaust gasInfo
- Publication number
- JPH10244167A JPH10244167A JP9051706A JP5170697A JPH10244167A JP H10244167 A JPH10244167 A JP H10244167A JP 9051706 A JP9051706 A JP 9051706A JP 5170697 A JP5170697 A JP 5170697A JP H10244167 A JPH10244167 A JP H10244167A
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- catalyst
- layer
- supported
- flow direction
- 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 claims abstract description 48
- 230000002093 peripheral effect Effects 0.000 claims abstract description 9
- 230000001590 oxidative effect Effects 0.000 claims description 14
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 abstract description 14
- 238000000746 purification Methods 0.000 abstract description 11
- 230000003647 oxidation Effects 0.000 abstract description 4
- 238000007254 oxidation reaction Methods 0.000 abstract description 4
- 229910052697 platinum Inorganic materials 0.000 abstract description 2
- 229910052763 palladium Inorganic materials 0.000 abstract 2
- 229910052802 copper Inorganic materials 0.000 abstract 1
- 229910052741 iridium Inorganic materials 0.000 abstract 1
- 229910052703 rhodium Inorganic materials 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 35
- 239000010410 layer Substances 0.000 description 28
- 241000264877 Hippospongia communis Species 0.000 description 10
- 238000004519 manufacturing process Methods 0.000 description 8
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 6
- 229930195733 hydrocarbon Natural products 0.000 description 6
- 150000002430 hydrocarbons Chemical class 0.000 description 6
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 5
- 239000004215 Carbon black (E152) Substances 0.000 description 4
- 239000004480 active ingredient Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 239000011230 binding agent Substances 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 229910010293 ceramic material Inorganic materials 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 229910052878 cordierite Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 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 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000005219 brazing Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、内燃機関、特にデ
ィーゼルエンジンから出された排気ガスを効率良く浄化
できる装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus capable of efficiently purifying exhaust gas emitted from an internal combustion engine, particularly a diesel engine.
【０００２】[0002]
【従来の技術】内燃機関から出された排気ガスは排気管
路中を流れ最終的には外部に放出されるが、有害物質を
そのまま外部に放出しないように、排気ガスは浄化され
た後に外部に放出されることが要求されている。ディー
ゼルエンジンから出された排気ガスに関しては窒素酸化
物（ＮＯｘ）の低減に加えて、最近では、環境上の観点
から、炭化水素やカーボン等のパティキュレートの低減
も求められている。2. Description of the Related Art Exhaust gas emitted from an internal combustion engine flows through an exhaust pipe and is finally released to the outside. However, the exhaust gas is purified after being purified so as not to release harmful substances to the outside as it is. Is required to be released. With respect to exhaust gas emitted from diesel engines, in addition to reduction of nitrogen oxides (NOx), reduction of particulates such as hydrocarbons and carbon has recently been required from an environmental point of view.
【０００３】従来からパティキュレートのフィルターと
して用いられているタイプのものは、排気ガスの流れ方
向に対して無数の小孔が連通してなるハニカム状のモノ
リス体であって、排気ガスの流れ方向に対して開放され
た両側端面が平面を形成し且つ小孔の大きさが均一に設
計されたものが一般的であった。このようなフィルター
中を排気ガスが流れるときには、均一な流量で流れるわ
けではなく、その中央部から外周部に向かって流量が減
る。従って、フィルターのパティキュレートの捕集効率
を高めるために、例えば、実開平５−３２７１５には、
触媒体中の排気ガスの流れを平均化することが提案さ
れ、その具体化物として、１つの触媒ケース内に特別な
構成の２つのモノリス型触媒体を配設してなる排気ガス
浄化装置が開示されている。また、実開平４−２３１６
１４には、外層側で背圧が低く内層側で背圧が高くなる
ように、外層側の担体から内層側の担体にかけて次第に
セル数が大きくなる構成のパティキュレートフィルタが
開示されている。しかしながら、上述のものも含めて提
案されているものは、いずれも、製造が困難であるばか
りでなく、パティキュレートも吸着作用によってのみ浄
化されていたことから、浄化効率も期待したほど向上し
なかった。A type of filter conventionally used as a particulate filter is a honeycomb-shaped monolith having a number of small holes communicating with the flow direction of the exhaust gas. In general, both end faces open to the outside form a flat surface and the size of the small holes is designed to be uniform. When the exhaust gas flows through such a filter, the exhaust gas does not flow at a uniform flow rate, but the flow rate decreases from the central portion to the outer peripheral portion. Therefore, in order to increase the particulate collection efficiency of the filter, for example, Japanese Utility Model Laid-Open No. 5-32715 includes
It has been proposed to average the flow of exhaust gas in a catalyst body, and as a concrete example thereof, an exhaust gas purifying apparatus in which two monolithic catalyst bodies having a special configuration are arranged in one catalyst case is disclosed. Have been. In addition, 4-2316
No. 14 discloses a particulate filter having a configuration in which the number of cells gradually increases from the carrier on the outer layer side to the carrier on the inner layer side so that the back pressure is lower on the outer layer side and the back pressure is higher on the inner layer side. However, all of the proposed ones, including the ones described above, are not only difficult to manufacture, but the particulates are also purified only by the adsorption action, so the purification efficiency is not improved as expected. Was.
【０００４】従って、最近では、触媒を利用してパティ
キュレートを酸化することにより浄化することが提案さ
れている。しかしながら、パティキュレートは、その特
性上高温時には酸化力の弱い触媒に接触させることによ
り浄化できるが、高温時に酸化力の強い触媒に接触させ
ると触媒の有する強力な酸化力により、排気ガス中に同
時に含まれるＳＯ2の酸化が進み有害物質であるＳＯ3及
び硫酸ミスト（以下、「サルフェート」と称す）が生成
されてしまうことが知られている。従って、この手法を
利用した場合には、低温域における酸化性能又は高温域
におけるサルフェート発生の抑制機能のいずれかを犠牲
にするか、或いは、触媒浄化装置の構成を複雑化して、
即ち、低温域及び高温域の両方に対応できるよう複数の
触媒装置を設け、排気ガスの温度に応じて排気ガスの流
れを変えるしかないと考えられていた。Accordingly, it has recently been proposed to purify particulates by oxidizing particulates using a catalyst. However, due to its characteristics, particulates can be purified by contact with a catalyst having a low oxidizing power at high temperatures. It is known that oxidation of SO 2 contained therein progresses to produce SO 3 and sulfuric acid mist (hereinafter referred to as “sulfate”), which are harmful substances. Therefore, when this method is used, either sacrifice either the oxidation performance in the low temperature range or the function of suppressing the generation of sulfate in the high temperature range, or complicate the configuration of the catalyst purification device,
That is, it has been considered that a plurality of catalyst devices must be provided so as to cope with both the low temperature range and the high temperature range, and the flow of the exhaust gas must be changed according to the temperature of the exhaust gas.
【０００５】[0005]
【発明が解決しようとする課題】それ故、本発明は、上
記の欠点を解消した、簡便な構成で、且つ、排気ガス中
に含まれるパティキュレートを、サルフェートの生成を
増大させることなく、広い温度域にわたって高効率で浄
化できる装置を提供することを目的とする。SUMMARY OF THE INVENTION Therefore, the present invention has a simple structure which solves the above-mentioned drawbacks, and has a large particle size in exhaust gas without increasing the production of sulfate. It is an object of the present invention to provide a device capable of purifying with high efficiency over a temperature range.
【０００６】[0006]
【課題を解決するための手段】本発明者は、鋭意研究の
結果、触媒体に酸化力の異なる２種類以上の触媒を担持
させ、且つ、排気ガスがその温度に応じて該触媒体中の
特定の流路を自発的に流れるように構成することによ
り、排気ガス中のパティキュレートの浄化効率を上げつ
つ、しかも、サルフェートの生成を増大させることを回
避することに成功した。Means for Solving the Problems As a result of intensive studies, the present inventors have made it possible to carry two or more types of catalysts having different oxidizing powers on a catalyst body, and to control the temperature of the exhaust gas in the catalyst body. By configuring the specific flow path to flow spontaneously, the purification efficiency of the particulates in the exhaust gas has been increased, and the increase in the production of sulfate has been successfully avoided.
【０００７】即ち、本発明は、モノリス型のハニカム状
本体に触媒が担持された排気ガス浄化用触媒構造体であ
って、該構造体の排気ガスの流れ方向に対して同心円状
に構成された多層構造からなり、外周側から中心側に向
かって層のセル数が多くなり、且つ、排気ガスの流れ方
向からみてその中心部に酸化力の強い触媒が担持され且
つその外周部に酸化力の弱い触媒が担持されていること
を特徴とするものである。好ましくは、全断面積に対す
る中心部の層の断面積比が５％〜５０％である。That is, the present invention relates to a catalyst structure for purifying exhaust gas in which a catalyst is supported on a monolithic honeycomb-shaped main body, which is formed concentrically with respect to the flow direction of exhaust gas in the structure. It has a multi-layer structure, the number of cells in the layer increases from the outer peripheral side toward the center side, and a strong oxidizing catalyst is supported at the central part when viewed from the flow direction of exhaust gas, and the outer peripheral part has a strong oxidizing power. It is characterized in that a weak catalyst is supported. Preferably, the cross-sectional area ratio of the central layer to the total cross-sectional area is 5% to 50%.
【０００８】本発明の構成の触媒構造体を用いた場合、
始動時などエンジンが低速回転・低負荷下にあるとき
は、排気ガスは流速が遅いので、外周方向への拡散機能
は低く、主に中心部に流入する。中心部には、酸化力の
強い触媒、即ち、低温域においても酸化力のある触媒が
担持されているので、排気ガス中のパティキュレートは
酸化されて効率的に低減する。一方、定常運転時などエ
ンジンが高速運転・高負荷下にあるときは、排気ガスは
流速が速く、且つ、構造体の中心部から外周部に向かう
につれてセル数が少なくなっていることから、中心部の
セル壁に衝突し、その衝突の勢いで排気ガスは外周方向
へ拡散して、そこから構造体中に入る。外周方向には、
酸化力の弱い触媒、即ち、高温域において酸化力が弱く
サルフェートの生成機能までは有さない触媒が担持され
ているので、排気ガス中のパティキュレートが酸化され
て低減されるが、サルフェートは生成されない。When the catalyst structure of the present invention is used,
When the engine is rotating at a low speed and under a low load, such as at the time of starting, the exhaust gas has a low flow velocity, and therefore has a low diffusion function in the outer peripheral direction, and flows mainly into the center. Since a catalyst having a strong oxidizing power, that is, a catalyst having an oxidizing power even in a low temperature range, is supported in the central portion, the particulates in the exhaust gas are oxidized and efficiently reduced. On the other hand, when the engine is operating at high speed and under high load such as during steady operation, the exhaust gas has a high flow velocity, and the number of cells decreases from the center to the outer periphery of the structure. The exhaust gas diffuses in the outer peripheral direction with the force of the collision and enters the structure from there. In the outer circumferential direction,
Since a catalyst having a weak oxidizing power, that is, a catalyst having a weak oxidizing power in a high temperature range and having no function of generating sulfate is supported, particulates in exhaust gas are oxidized and reduced, but sulfate is generated. Not done.
【０００９】従って、広い温度域にわたって排気ガス中
のパティキュレートの浄化効率を、サルフェートの生成
量を増大することなく、上げることができる。Therefore, the purification efficiency of particulates in exhaust gas over a wide temperature range can be increased without increasing the amount of sulfate produced.
【００１０】[0010]
【発明の実施の形態】以下、本発明の触媒構造体の実施
の形態の一つを、図面に基づいて詳細に説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a catalyst structure according to the present invention will be described below in detail with reference to the drawings.
【００１１】構造 図１は、本発明に係わるモノリス型のハニカム状本体に
活性成分が担持された排気ガス浄化用触媒構造体１の一
つの具体化物の、排気ガスの流れ方向に対して垂直な断
面の概略図である。この構造体は、排気ガスの流れ方向
に対して、同心円状に構成された３層（内層２、中層
３、外層４）が互いに結合されてなる多層構造である。
なお、３層以上でもよいことは言うまでもない。工業上
の観点からは、最大で１０層程度であろう。内層には酸
化力の最も強い触媒が担持され、外層には酸化力の最も
弱い触媒が担持され、中層には酸化力が中間の触媒が担
持されている。また、内層のハニカム体が最もセル数が
多く、外層のハニカム体が最もセル数が少なく、中層の
ハニカム体のハニカム数が中間である。また、内層の断
面積が全体の２０％以下となるように構成するのが好ま
しい。この装置のように、３層構造とした場合には、ハ
ニカム体の断面積とセル数とを以下の表１に示すような
割合で設定すると好適な効果が得られる。FIG. 1 is a cross- sectional view of one embodiment of an exhaust gas purifying catalyst structure 1 in which an active component is supported on a monolithic honeycomb body according to the present invention, which is perpendicular to the exhaust gas flow direction. It is the schematic of a cross section. This structure has a multilayer structure in which three layers (inner layer 2, middle layer 3, and outer layer 4) formed concentrically with respect to the flow direction of the exhaust gas are connected to each other.
Needless to say, three or more layers may be used. From an industrial point of view, there will be at most about 10 layers. The inner layer carries a catalyst having the strongest oxidizing power, the outer layer carries a catalyst having the weakest oxidizing power, and the middle layer carries a catalyst having an intermediate oxidizing power. Further, the inner layer has the largest number of cells, the outer layer has the smallest number of cells, and the middle layer has an intermediate number of honeycombs. It is preferable that the inner layer has a cross-sectional area of 20% or less of the whole. In the case of a three-layer structure as in this device, a suitable effect can be obtained by setting the cross-sectional area of the honeycomb body and the number of cells at the ratios shown in Table 1 below.
【００１２】[0012]
【表１】 [Table 1]
【００１３】また、内層、中層、外層にそれぞれ担持さ
せる触媒（活性成分）としては、以下の表２に示すよう
に選択すると好適な結果が得られる。Further, when the catalyst (active ingredient) supported on each of the inner layer, the middle layer and the outer layer is selected as shown in Table 2 below, suitable results can be obtained.
【００１４】[0014]
【表２】 [Table 2]
【００１５】製造方法 本発明の排気ガス浄化用触媒構造体は、モノリス型のハ
ニカム状本体に少なくとも２種類の活性成分を担持させ
ることにより製造できる。公知の製造方法を利用できる
が、ここでも、簡単に説明する。まず、モノリス型のハ
ニカム状本体を製造する。構造体の材質では、耐熱ステ
ンレス鋼等のメタルが比熱が小さく温度上昇が速いた
め、触媒活性化までの時間が短いと言うことで用いられ
ているが、最近では、コージェライトなどの機械的強度
や耐熱性に優れたセラミック材料も使用されている。前
者は、箔製の波板と平板とを交互に巻き回してハニカム
構造とし、その後ろう付け等により一部又は全体を接合
することにより製造するのが一般的であり、後者は、対
応するセラミック粉末をアルミナゾルやシリカゾル等の
バインダー及び水を混練し、これからハニカム構造に成
形した後に乾燥・焼成することにより製造するが一般的
である。 Manufacturing Method The exhaust gas purifying catalyst structure of the present invention can be manufactured by supporting at least two types of active components on a monolithic honeycomb body. Although a known manufacturing method can be used, a brief description will be given here. First, a monolith-type honeycomb main body is manufactured. In structural materials, heat-resistant stainless steel and other metals are used because their specific heat is small and the temperature rises quickly, so the time to activate the catalyst is short. Recently, however, mechanical strength such as cordierite has been used. Ceramic materials with excellent heat resistance are also used. The former is generally manufactured by winding a foil corrugated sheet and a flat plate alternately to form a honeycomb structure, and thereafter joining a part or the whole by brazing or the like, and the latter is generally manufactured by a corresponding ceramic. The powder is generally produced by kneading a binder such as alumina sol or silica sol and water, forming the mixture into a honeycomb structure, followed by drying and firing.
【００１６】本発明の場合には、ハニカム状本体の材質
としては、セラミック材料を使用するのが好ましい。In the case of the present invention, it is preferable to use a ceramic material as the material of the honeycomb-shaped main body.
【００１７】ハニカム状本体への活性成分の担持は、例
えば、該本体をウオッシュコート液（例えば、γ−アル
ミナ粉末＋アルミナゾル＋水）に浸漬し、乾燥し焼成し
てウオッシュコート層を該本体上に形成し、その後に、
活性成分を含む化合物を水に溶解してなる溶液、例え
ば、塩化白金酸の水溶液に浸漬し、引上げ（又は濃
縮）、乾燥及び焼成をすることにより達成することがで
きる。或いは、活性金属成分を粒子の形態で（例えば白
金粒子として）供給し、これに金属酸化物粉状担体（例
えばアルミナ担体）と無機バインダーと水とを加えてス
ラリーとし、これをハニカム状本体に塗布し、乾燥し、
焼成することによっても、ハニカム状本体への活性成分
の担持は可能である。The supporting of the active component on the honeycomb-shaped main body is performed, for example, by immersing the main body in a washcoat liquid (eg, γ-alumina powder + alumina sol + water), drying and firing to form a washcoat layer on the main body. And then
This can be achieved by immersing in a solution containing a compound containing the active ingredient in water, for example, an aqueous solution of chloroplatinic acid, and pulling (or concentrating), drying, and baking. Alternatively, the active metal component is supplied in the form of particles (for example, as platinum particles), and a metal oxide powder carrier (for example, an alumina carrier), an inorganic binder, and water are added thereto to form a slurry, which is then applied to the honeycomb body. Apply, dry,
By firing, it is possible to carry the active component on the honeycomb-shaped main body.
【００１８】本発明の場合には、少なくとも２種類の活
性成分を担持させることを特徴とする。従って、上述の
方法はいずれも利用可能であるが、ハニカムをマスキン
グしスラリーを必要箇所（多段）に担持するという多段
工程により製造することを特徴とする。The present invention is characterized in that at least two kinds of active ingredients are supported. Therefore, although any of the above-mentioned methods can be used, it is characterized in that it is manufactured by a multi-step process in which the honeycomb is masked and the slurry is supported at necessary places (multi-step).
【００１９】[0019]
実施例１ 図１に示された排気ガス浄化用触媒構造体を用いて炭化
水素（ＨＣ）の浄化性能とサルフェートの生成傾向を調
べた。なお、具体的な触媒構造体の構造・材質は以下の
通りであった。Example 1 The exhaust gas purification catalyst structure shown in FIG. 1 was used to examine hydrocarbon (HC) purification performance and sulfate generation tendency. The specific structure and material of the catalyst structure were as follows.
【００２０】[0020]
【表３】 [Table 3]
【００２１】なお、ハニカム状本体はコージェライトか
らなり、活性成分が溶液からの浸漬・引上げ法によりγ
ーアルミナ担体に担持され、これがアルミナゾルバイン
ダーによりハニカム本体に固着されてなる。Incidentally, the honeycomb-shaped main body is made of cordierite, and the active ingredient is γ by dipping and pulling up from a solution.
-Supported on an alumina carrier, which is fixed to the honeycomb body by an alumina sol binder.
【００２２】比較例１〜３ 比較例１〜３として、以下の触媒の活性成分が単一層か
らなる触媒構造体を、実施例と同様にして製造した。な
お、ハニカム状本体自体のサイズや材質は実施例のもの
と同じである。Comparative Examples 1 to 3 As Comparative Examples 1 to 3, the following catalyst structures were prepared in the same manner as in Examples, in which the active components of the catalyst consisted of a single layer. The size and material of the honeycomb-shaped main body itself are the same as those of the embodiment.
【００２３】[0023]
【表４】 [Table 4]
【００２４】触媒性能の試験 ディーゼルエンジンからの排気ガスの浄化処理を模擬し
た以下の条件下で試験を行って、種々の排気温度（厳密
には、触媒構造体の入口における排気ガスの温度）及び
エンジンの回転数（空間速度（ＧＨＳＶ）：２０，００
０〜１００，０００ｈｒ-1）における、炭化水素（Ｈ
Ｃ）の浄化率（％）とサルフェート（ＰＭ）生成の増減
率を調べた。 Test of Catalytic Performance A test was conducted under the following conditions simulating the treatment of purifying exhaust gas from a diesel engine, and various exhaust temperatures (strictly speaking, the temperature of the exhaust gas at the inlet of the catalyst structure) and Engine speed (space velocity (GHSV): 20,000)
0 to 100,000 hr -1 )
The purification rate (%) of C) and the increase / decrease rate of sulfate (PM) production were examined.
【００２５】試験条件 ガスの組成 ＮＯ： １０００ｐｐｍ Ｃ2Ｈ4： １０００ｐｐｍ Ｏ2： ５％ Ｈｅ： 残部Test conditions Gas composition NO: 1000 ppm C 2 H 4 : 1000 ppm O 2 : 5% He: balance
【００２６】この結果は、図２と図３に示した通りであ
った。図２及び３から、本発明の装置を用いたときに
は、サルフェートの生成を抑制しつつ、ＨＣ（パティキ
ュレート）の浄化効率を有意的に高めることに成功して
いることがわかる。The results are as shown in FIGS. 2 and 3, it can be seen that when the apparatus of the present invention was used, the purification efficiency of HC (particulate) was significantly increased while the production of sulfate was suppressed.
【００２７】[0027]
【発明の効果】本発明の触媒構造体によれば、広い温度
域にわたって、サルフェートの生成量を増大することな
く、排気ガス中のパティキュレートの浄化効率を上げる
ことができる。According to the catalyst structure of the present invention, the purification efficiency of particulates in exhaust gas can be increased over a wide temperature range without increasing the amount of sulfate generated.
【図１】本発明に係わる排気ガス浄化用触媒構造体の一
具体化物の、排気ガスの流れ方向に対して垂直な断面の
概略図である。FIG. 1 is a schematic view of a cross section of an embodiment of an exhaust gas purifying catalyst structure according to the present invention, the cross section being perpendicular to a flow direction of exhaust gas.
【図２】実施例と比較例１〜３の触媒構造体を用いた場
合の炭化水素（ＨＣ）の浄化率（％）を比較して示した
図である。FIG. 2 is a diagram showing a comparison between the conversion rates (%) of hydrocarbons (HC) when the catalyst structures of the example and comparative examples 1 to 3 are used.
【図３】実施例と比較例１〜３の触媒構造体を用いた場
合のサルフェート生成の増減率を比較して示した図であ
る。FIG. 3 is a diagram showing a comparison between the increase and decrease rates of sulfate production when the catalyst structures of the example and comparative examples 1 to 3 are used.
１：排気ガス浄化用触媒構造体 ２：内層、３：中層、４：外層 1: Exhaust gas purification catalyst structure 2: Inner layer, 3: Middle layer, 4: Outer layer
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 ＦＩ Ｂ０１Ｊ 23/46 Ｂ０１Ｊ 23/46 ３１１Ａ ３１１ 23/50 Ａ 23/50 23/72 Ａ 23/72 Ｂ０１Ｄ 53/36 １０４Ａ １０４Ｂ ──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 6 Identification code FI B01J 23/46 B01J 23/46 311A 311 23/50 A 23/50 23/72 A 23/72 B01D 53/36 104A 104B
Claims (2)
持された排気ガス浄化用触媒構造体であって、 該構造体の排気ガスの流れ方向に対して同心円状に構成
された多層構造からなり、外周側から中心側に向かって
層のセル数が多くなり、且つ、 排気ガスの流れ方向からみてその中心部に酸化力の強い
触媒が担持され且つその外周部に酸化力の弱い触媒が担
持されている、ことを特徴とする排気ガス浄化用触媒構
造体。An exhaust gas purifying catalyst structure in which a catalyst is supported on a monolithic honeycomb-shaped main body, comprising a multilayer structure formed concentrically with respect to a flow direction of exhaust gas in the structure. The number of cells in the layer increases from the outer peripheral side toward the central side, and a catalyst having a strong oxidizing power is supported at the center thereof and a catalyst having a weak oxidizing power is supported at the outer peripheral portion thereof when viewed from the flow direction of the exhaust gas. An exhaust gas purifying catalyst structure, comprising:
が５％〜５０％であることを特徴とする請求項１に記載
の排気ガス浄化用触媒構造体。2. The exhaust gas purifying catalyst structure according to claim 1, wherein the ratio of the cross-sectional area of the central layer to the total cross-sectional area is 5% to 50%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9051706A JPH10244167A (en) | 1997-03-06 | 1997-03-06 | Catalyst structure body for purifying exhaust gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9051706A JPH10244167A (en) | 1997-03-06 | 1997-03-06 | Catalyst structure body for purifying exhaust gas |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10244167A true JPH10244167A (en) | 1998-09-14 |
Family
ID=12894350
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9051706A Pending JPH10244167A (en) | 1997-03-06 | 1997-03-06 | Catalyst structure body for purifying exhaust gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10244167A (en) |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2342055A (en) * | 1998-09-14 | 2000-04-05 | Ford Global Tech Inc | Exhaust treatment device with varying cell density |
| EP1312776A2 (en) * | 2001-11-16 | 2003-05-21 | Isuzu Motors Limited | Exhaust gas purification system |
| EP1375854A1 (en) * | 2001-04-03 | 2004-01-02 | Ngk Insulators, Ltd. | Honeycomb structure and its assembly |
| WO2004070177A1 (en) * | 2003-01-07 | 2004-08-19 | Peugeot Citroen Automobiles Sa | Aid system for regeneration of a particle filter in an exhaust line of a diesel engine |
| JP2005144284A (en) * | 2003-11-13 | 2005-06-09 | Ngk Insulators Ltd | Ceramic honeycomb structure |
| FR2869072A1 (en) * | 2004-04-19 | 2005-10-21 | Peugeot Citroen Automobiles Sa | Device for purifying engine exhaust gas comprises a catalytic coating on a substrate, where the coating and/or substrate has a physicochemical property that varies across the direction of gas flow |
| JP2006255638A (en) * | 2005-03-18 | 2006-09-28 | Toyota Motor Corp | Catalyst for exhaust-gas cleaning and exhaust-gas cleaning apparatus equipped with the catalyst for exhaust-gas cleaning |
| JP2008018370A (en) * | 2006-07-14 | 2008-01-31 | Denso Corp | Ceramic catalyst body |
| JP2011194353A (en) * | 2010-03-23 | 2011-10-06 | Ngk Insulators Ltd | Honeycomb structure |
| US8568674B1 (en) | 2012-08-10 | 2013-10-29 | Basf Corporation | Diesel oxidation catalyst composites |
| JP2013244438A (en) * | 2012-05-24 | 2013-12-09 | Toyota Motor Corp | Catalytic converter |
| JP2014151305A (en) * | 2013-02-13 | 2014-08-25 | Toyota Motor Corp | Catalytic converter |
| WO2014162183A1 (en) * | 2013-04-03 | 2014-10-09 | Toyota Jidosha Kabushiki Kaisha | Catalyst converter |
| CN104936694A (en) * | 2013-01-23 | 2015-09-23 | 丰田自动车株式会社 | Catalytic converter |
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1997
- 1997-03-06 JP JP9051706A patent/JPH10244167A/en active Pending
Cited By (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2342055A (en) * | 1998-09-14 | 2000-04-05 | Ford Global Tech Inc | Exhaust treatment device with varying cell density |
| US7041359B2 (en) | 2001-04-03 | 2006-05-09 | Ngk Insulators, Ltd. | Honeycomb structure and assembly thereof |
| EP1375854A1 (en) * | 2001-04-03 | 2004-01-02 | Ngk Insulators, Ltd. | Honeycomb structure and its assembly |
| EP1375854A4 (en) * | 2001-04-03 | 2004-10-20 | Ngk Insulators Ltd | Honeycomb structure and its assembly |
| EP1312776A2 (en) * | 2001-11-16 | 2003-05-21 | Isuzu Motors Limited | Exhaust gas purification system |
| EP1312776A3 (en) * | 2001-11-16 | 2004-05-12 | Isuzu Motors Limited | Exhaust gas purification system |
| WO2004070177A1 (en) * | 2003-01-07 | 2004-08-19 | Peugeot Citroen Automobiles Sa | Aid system for regeneration of a particle filter in an exhaust line of a diesel engine |
| JP4504660B2 (en) * | 2003-11-13 | 2010-07-14 | 日本碍子株式会社 | Ceramic honeycomb structure |
| JP2005144284A (en) * | 2003-11-13 | 2005-06-09 | Ngk Insulators Ltd | Ceramic honeycomb structure |
| FR2869072A1 (en) * | 2004-04-19 | 2005-10-21 | Peugeot Citroen Automobiles Sa | Device for purifying engine exhaust gas comprises a catalytic coating on a substrate, where the coating and/or substrate has a physicochemical property that varies across the direction of gas flow |
| EP1589199A1 (en) * | 2004-04-19 | 2005-10-26 | Peugeot Citroen Automobiles S.A. | Exhaust gas purification device |
| JP2006255638A (en) * | 2005-03-18 | 2006-09-28 | Toyota Motor Corp | Catalyst for exhaust-gas cleaning and exhaust-gas cleaning apparatus equipped with the catalyst for exhaust-gas cleaning |
| JP2008018370A (en) * | 2006-07-14 | 2008-01-31 | Denso Corp | Ceramic catalyst body |
| JP2011194353A (en) * | 2010-03-23 | 2011-10-06 | Ngk Insulators Ltd | Honeycomb structure |
| JP2013244438A (en) * | 2012-05-24 | 2013-12-09 | Toyota Motor Corp | Catalytic converter |
| US8568674B1 (en) | 2012-08-10 | 2013-10-29 | Basf Corporation | Diesel oxidation catalyst composites |
| CN104936694A (en) * | 2013-01-23 | 2015-09-23 | 丰田自动车株式会社 | Catalytic converter |
| US10071365B2 (en) | 2013-01-23 | 2018-09-11 | Toyota Jidosha Kabushiki Kaisha | Catalytic converter |
| JP2014151305A (en) * | 2013-02-13 | 2014-08-25 | Toyota Motor Corp | Catalytic converter |
| JP2014200728A (en) * | 2013-04-03 | 2014-10-27 | トヨタ自動車株式会社 | Catalyst converter |
| CN105073227A (en) * | 2013-04-03 | 2015-11-18 | 丰田自动车株式会社 | Catalyst converter |
| CN105073227B (en) * | 2013-04-03 | 2017-04-26 | 丰田自动车株式会社 | Catalyst converter |
| US9782723B2 (en) | 2013-04-03 | 2017-10-10 | Toyota Jidosha Kabushiki Kaisha | Catalyst converter |
| WO2014162183A1 (en) * | 2013-04-03 | 2014-10-09 | Toyota Jidosha Kabushiki Kaisha | Catalyst converter |
| DE112014001824B4 (en) * | 2013-04-03 | 2020-08-06 | Toyota Jidosha Kabushiki Kaisha | Catalytic converter |
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