JP2006205134A - Exhaust gas cleaning catalyst and exhaust gas cleaning control device using it - Google Patents

Exhaust gas cleaning catalyst and exhaust gas cleaning control device using it Download PDF

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JP2006205134A
JP2006205134A JP2005024285A JP2005024285A JP2006205134A JP 2006205134 A JP2006205134 A JP 2006205134A JP 2005024285 A JP2005024285 A JP 2005024285A JP 2005024285 A JP2005024285 A JP 2005024285A JP 2006205134 A JP2006205134 A JP 2006205134A
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exhaust gas
catalyst
region
sensor
atmosphere
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JP4506487B2 (en
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Hiromasa Suzuki
宏昌 鈴木
Takahiko Fujiwara
孝彦 藤原
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Toyota Motor Corp
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Toyota Motor Corp
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Priority to CN200680003588XA priority patent/CN101111309B/en
Priority to KR1020077017559A priority patent/KR20070095988A/en
Priority to CA002595717A priority patent/CA2595717A1/en
Priority to EP06701445A priority patent/EP1841529A1/en
Priority to US11/883,444 priority patent/US20090124494A1/en
Priority to PCT/JP2006/301177 priority patent/WO2006080369A1/en
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    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
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    • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
    • F01N11/007—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus
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    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
    • F01N13/0097—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series the purifying devices are arranged in a single housing
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    • 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
    • F01N3/18—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 methods of operation; Control
    • F01N3/20—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 methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
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    • 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
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    • F01N3/2803—Construction of catalytic reactors characterised by structure, by material or by manufacturing of catalyst support
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Abstract

<P>PROBLEM TO BE SOLVED: To optimally control the air-fuel ratio of an internal combustion engine using a catalyst having an Rh region carrying only Rh as a noble metal. <P>SOLUTION: The air-flow ratio of an engine 3 is controlled by detecting the outgas atmosphere by a second sensor 33 using a catalyst forming an oxidized region 22 on the downstream side of the Rh region. H<SB>2</SB>generated in the Rh region in the rich atmosphere is consumed in the oxidized region 22, thereby preventing a sudden change point of the second sensor 33 from being fluctuated. As a result, the time of the rich atmosphere is made longer to enhance NOx cleaning performance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、排ガス中のHC、CO及びNOx を浄化する三元触媒などの排ガス浄化用触媒と、それを用いた排ガス浄化制御装置に関し、詳しくは始動時などの低温域におけるHC浄化性能に優れた排ガス浄化用触媒と、それを用いて内燃機関の燃焼を最適に制御し高いNOx 浄化性能を発現できる排ガス浄化制御装置に関する。 The present invention relates to an exhaust gas purification catalyst such as a three-way catalyst that purifies HC, CO, and NO x in exhaust gas, and an exhaust gas purification control device using the same, and more specifically to HC purification performance in a low temperature range such as at the time of start-up. The present invention relates to an excellent exhaust gas purifying catalyst and an exhaust gas purifying control device capable of optimally controlling combustion of an internal combustion engine and exhibiting high NO x purification performance using the same.

自動車の排ガスを浄化する排ガス浄化用触媒として、従来より三元触媒が広く用いられている。この三元触媒は、アルミナなどの多孔質担体にPtなどの貴金属を担持してなり、理論空燃比近傍でCO，HC及びNOx を効率よく浄化することができる。 Conventionally, three-way catalysts have been widely used as exhaust gas purification catalysts for purifying automobile exhaust gas. This three-way catalyst is formed by supporting a noble metal such as Pt on a porous carrier such as alumina, and can efficiently purify CO, HC and NO x in the vicinity of the theoretical air-fuel ratio.

貴金属のうちPt及びPdは主としてCO及びHCの酸化浄化に寄与し、Rhは主としてNOx の還元浄化に寄与するとともに、RhにはPt又はPdのシンタリングを防止する作用がある。したがってPt又はPdとRhとを併用することにより、シンタリングによる活性点の減少により活性が低下するという不具合が抑制され、耐熱性が向上することがわかっている。 Of the noble metals, Pt and Pd mainly contribute to the oxidation and purification of CO and HC, Rh mainly contributes to the reduction and purification of NO x , and Rh has an action of preventing sintering of Pt or Pd. Therefore, it has been found that the combined use of Pt or Pd and Rh suppresses the disadvantage that the activity is lowered due to the reduction of the active site due to sintering, and improves the heat resistance.

三元触媒に担持されている貴金属は、その活性化温度より低い温度では触媒反応が生じない。そのためエンジン始動時など低温域の排ガス中では三元触媒が充分に機能せず、HCの排出量が多いという不具合があった。またコールドスタート時には、空燃比が燃料リッチ雰囲気となる場合が多く、排ガス中のHC量が多いということも上記不具合の一因である。   The noble metal supported on the three-way catalyst does not cause a catalytic reaction at a temperature lower than its activation temperature. For this reason, the three-way catalyst does not function sufficiently in the exhaust gas in a low temperature range such as when the engine is started, and there is a problem that the amount of HC emission is large. In addition, at the time of cold start, the air-fuel ratio often becomes a fuel-rich atmosphere, and the amount of HC in the exhaust gas is also a cause of the above-mentioned problems.

そこで特開平06−205983号公報などに見られるように、触媒の排ガス上流側における貴金属担持量を多くすることが行われている。触媒の排ガス上流側では、まだ層流とならない排ガスが触媒のセル壁に衝突するので、触媒の昇温が早く貴金属は比較的早期に活性化温度に到達する。そして活性化温度に到達後は、反応熱によってさらに温度が上昇し、触媒の下流側での昇温が促進されるので、低温域における浄化性能が向上する。   Therefore, as can be seen in Japanese Patent Laid-Open No. 06-205983, etc., increasing the amount of noble metal supported on the exhaust gas upstream side of the catalyst has been carried out. At the upstream side of the exhaust gas of the catalyst, the exhaust gas that has not yet become a laminar flow collides with the cell wall of the catalyst, so that the temperature of the catalyst rises quickly and the precious metal reaches the activation temperature relatively early. After reaching the activation temperature, the temperature further increases due to the reaction heat, and the temperature rise on the downstream side of the catalyst is promoted, so that the purification performance in the low temperature region is improved.

しかし例えばPtの担持量を多くすると、Ptの担持密度が高まるために、Pt粒子どうしのシンタリングが促進され活性が低下しやすいという不具合がある。   However, for example, when the amount of supported Pt is increased, the density of supported Pt increases, so that there is a problem that the sintering between the Pt particles is promoted and the activity tends to be lowered.

また貴金属として、特にHCの酸化活性が高いPdを用いることも知られている。例えば特開平08−024644号公報には、触媒の全長にPdを均一に担持するとともに、排ガス上流側にPtを担持した触媒が提案されている。この触媒によれば、空燃比の変動が大きい条件下で浄化性能に優れるPtを上流側に担持することで、ストイキ近傍における三元活性に優れたPdの特性と、リーン側におけるNOx 浄化性能に優れたPtの特性とのバランスが最適となり、高い浄化性能が発現される。 It is also known to use Pd, which has a particularly high HC oxidation activity, as a noble metal. For example, Japanese Patent Laid-Open No. 08-024644 proposes a catalyst in which Pd is uniformly supported on the entire length of the catalyst and Pt is supported on the exhaust gas upstream side. According to this catalyst, Pt, which has excellent purification performance under conditions with large fluctuations in the air-fuel ratio, is supported on the upstream side, Pd characteristics with excellent ternary activity in the vicinity of stoichiometry, and NO x purification performance on the lean side The balance with the excellent Pt characteristics is optimal, and high purification performance is exhibited.

さらに特開平08−332350号公報には、排ガス上流側にPdとRhを担持し、その下流側にPtとRhを担持した触媒が提案されている。この触媒によれば、上流側にPdが高濃度で担持されているために低温域におけるHC浄化性能に優れ、高温での耐久性にも優れている。そして上流側の反応熱によって下流側のPtの活性が高まり、高いNOx 浄化性能が発現される。 Further, JP 08-332350 A proposes a catalyst in which Pd and Rh are supported on the upstream side of exhaust gas and Pt and Rh are supported on the downstream side thereof. According to this catalyst, since Pd is supported at a high concentration on the upstream side, it is excellent in HC purification performance in a low temperature region and excellent in durability at high temperature. The upstream reaction heat increases the downstream Pt activity, and high NO x purification performance is exhibited.

しかしPdとRhとが共存する場合には、PtとRhとが共存する場合に比べてNOx 浄化性能が低いという問題がある。またPdはPtに比べてRhとの合金化が進行しやすく、合金化によってRhの特性が低下するという不具合もある。さらにRhは資源的にきわめて稀少であり、Rhを効率よく活用するとともに、その劣化を抑制して耐熱性を高めることが望まれている。 However, when Pd and Rh coexist, there is a problem that the NO x purification performance is lower than when Pt and Rh coexist. In addition, Pd is more likely to be alloyed with Rh than Pt, and there is also a problem that Rh characteristics deteriorate due to alloying. Furthermore, Rh is extremely rare in terms of resources, and it is desired to use Rh efficiently and to suppress its deterioration and increase heat resistance.

ところで三元触媒は、ストイキ近傍の排ガス雰囲気中でHC及びCOを酸化し、NOx を還元して浄化するものであるために、排ガス雰囲気がストイキ近傍となるようにエンジンの空燃比を制御することが必要不可欠である。この制御は、エンジンからの排ガス中の酸素濃度など触媒入ガス雰囲気に関連した物理量を検出し、それに基づいてエンジンの空燃比（ A/F ）をフィードバック制御することで行うことができる。しかし、リッチ空燃比で燃焼された排ガスであっても、三元触媒中でHCなどが消費されることによって触媒出ガスの雰囲気がストイキあるいはリーンとなるために、エンジン直下の排ガス雰囲気と、三元触媒の出ガスの雰囲気とが異なる場合がある。 By the way, the three-way catalyst oxidizes HC and CO in the exhaust gas atmosphere near the stoichiometric, and reduces and purifies NO x. Therefore, the air-fuel ratio of the engine is controlled so that the exhaust gas atmosphere becomes near the stoichiometric. It is essential. This control can be performed by detecting a physical quantity related to the catalyst input gas atmosphere such as the oxygen concentration in the exhaust gas from the engine and feedback-controlling the air-fuel ratio (A / F) of the engine based on the detected physical quantity. However, even if the exhaust gas is burned at a rich air-fuel ratio, the atmosphere of the catalyst outgas becomes stoichiometric or lean due to the consumption of HC in the three-way catalyst. The atmosphere of the outgas of the original catalyst may be different.

そこで従来は、三元触媒の入ガス雰囲気に関連した物理量を検出する第１センサと、三元触媒の出ガス雰囲気に関連した物理量を検出する第２センサとを設け、両センサの出力差を判断し、噴射燃料値を変化させている。これにより三元触媒の活性の程度に応じて空燃比を最適に制御することができ、高い浄化率を確保できる。また両センサの出力による両雰囲気に差があるべきときに、その差が所定範囲より小さくなったことを検出することで、三元触媒の劣化の程度も判定することができ、三元触媒の交換時期を明確に知ることができる。
特開平06−205983号 特開平08−024644号 特開平08−332350号 Therefore, conventionally, a first sensor for detecting a physical quantity related to the inlet gas atmosphere of the three-way catalyst and a second sensor for detecting a physical quantity related to the outlet gas atmosphere of the three-way catalyst are provided, and an output difference between both sensors is provided. Judging and changing the injected fuel value. As a result, the air-fuel ratio can be optimally controlled according to the degree of activity of the three-way catalyst, and a high purification rate can be ensured. In addition, when there should be a difference between the two atmospheres due to the outputs of both sensors, it is possible to determine the degree of deterioration of the three-way catalyst by detecting that the difference is smaller than the predetermined range. Clearly know when to replace.
JP 06-205983 JP 08-024644 JP 08-332350 A

本願出願人は、特願2004−262301号において、排ガス流入側端面から担体基材の全長の４／10以下の領域にRh及びPtを担持した共存領域と、共存領域から排ガス下流側に形成され排ガス流れ方向にRhを均一に担持したRh領域と、を有する触媒担持層をもつ触媒を提案している。この触媒によれば、排ガス下流側より高温になりやすい排ガス上流側にPtとRhが担持された共存領域が形成されているため、共存領域ではRhによってPtのシンタリングが抑制され活性の低下が抑制される。さらに、共存領域においてPtとRhとが合金化してRhの特性が低下したとしても、Rh領域に担持されているRhが十分な特性を発揮し、また共存領域は全長の４／10以下であるので合金化するRhが少なく、Rhを効率よく活用することができる。   In the Japanese Patent Application No. 2004-262301, the applicant of the present application is formed on the exhaust gas inflow side end face to a coexistence region in which Rh and Pt are supported in a region of 4/10 or less of the total length of the carrier substrate, and from the coexistence region to the exhaust gas downstream A catalyst having a catalyst supporting layer having an Rh region in which Rh is uniformly supported in the exhaust gas flow direction is proposed. According to this catalyst, since a coexistence region in which Pt and Rh are supported is formed on the exhaust gas upstream side, which tends to be hotter than the exhaust gas downstream side, Pt sintering is suppressed by Rh in the coexistence region, and the activity is reduced. It is suppressed. Furthermore, even if Pt and Rh are alloyed in the coexistence region and the properties of Rh are reduced, Rh supported in the Rh region exhibits sufficient properties, and the coexistence region is less than 4/10 of the total length. Therefore, there is little Rh to alloy and Rh can be used efficiently.

ところが特願2004−262301号で提案された触媒を三元触媒として用い、上記した第１センサと第２センサの出力値によってエンジンの空燃比を制御しようとすると、第２センサの出力値の誤差が大きいという問題が発生した。つまり、エンジンがリッチ空燃比で燃焼された直後は、三元触媒からの出ガスはHCなどがNOx の還元に消費されてリーン雰囲気であるべきであるのに、第２センサが三元触媒の出ガスをリッチ雰囲気として出力するという不具合があった。このようになると空燃比をストイキとする制御が行われてしまうために、NOx 浄化率が低下してしまうばかりか、空燃比制御の精度が低下し、三元触媒の劣化の程度を把握する精度も低下する。 However, if the catalyst proposed in Japanese Patent Application No. 2004-262301 is used as a three-way catalyst and the engine air-fuel ratio is controlled by the output values of the first sensor and the second sensor, an error in the output value of the second sensor. The problem that is large. That is, immediately after the engine is burned in the rich air-fuel ratio, though outlet gas from the three-way catalyst should be such as is consumed in the reduction of the NO x lean atmosphere HC, the second sensor is a three-way catalyst There was a problem that the output gas was output as a rich atmosphere. To this occurs when the control to make the air-fuel ratio and stoichiometry will take place, not only the NO x purification rate is lowered, reduces the accuracy of the air-fuel ratio control, to grasp the degree of deterioration of the three-way catalyst Accuracy is also reduced.

このような問題が生じる原因は、上記触媒の入ガスがリッチ雰囲気であると、Rh領域において水蒸気改質反応が促進されてH2が生成し、それが第２センサの出力急変点（しきい値）を変動させてしまうためと考えられる。 The reason why such a problem occurs is that when the catalyst input gas is in a rich atmosphere, the steam reforming reaction is promoted in the Rh region and H 2 is generated, which is the output sudden change point (threshold value) of the second sensor. Value).

本発明は、上記事情に鑑みてなされたものであり、Rh領域において生成したH2により生じる第２センサの出力急変点の不要な変動を抑制し、内燃機関の空燃比を最適に制御することを解決すべき課題とする。 The present invention has been made in view of the above circumstances, and suppresses unnecessary fluctuations in the output sudden change point of the second sensor caused by H 2 generated in the Rh region, and optimally controls the air-fuel ratio of the internal combustion engine. Is a problem to be solved.

上記課題を解決する本発明の排ガス浄化用触媒の特徴は、排ガス流路をもつ担体基材と、排ガス流路の表面に形成され多孔質酸化物担体と貴金属とを含んでなる触媒担持層と、を有する排ガス浄化用触媒であって、触媒担持層は、貴金属としてRhのみを担持したRh領域と、Rh領域の排ガス下流側に形成され少なくとも酸化活性を有する触媒金属を担持した酸化領域と、を有することにある。   The exhaust gas purifying catalyst of the present invention that solves the above problems is characterized in that a support base material having an exhaust gas flow path, a catalyst support layer formed on the surface of the exhaust gas flow path, comprising a porous oxide support and a noble metal, The catalyst support layer has an Rh region supporting only Rh as a noble metal, and an oxidation region formed on the exhaust gas downstream side of the Rh region and supporting a catalyst metal having at least oxidation activity, It is in having.

Rh担持領域の排ガス上流側における触媒担持層には、Rh及びPtを担持した共存領域を有することが望ましく、共存領域は担体基材の全長の４／10以下であり、Rhに対するPtの比率が重量比で10≦Pt／Rh≦60の範囲にあることが好ましい。また多孔質酸化物担体は、少なくともセリアを含むことが好ましい。   The catalyst support layer on the exhaust gas upstream side of the Rh support region preferably has a coexistence region supporting Rh and Pt, and the coexistence region is 4/10 or less of the total length of the support substrate, and the ratio of Pt to Rh is The weight ratio is preferably in the range of 10 ≦ Pt / Rh ≦ 60. The porous oxide support preferably contains at least ceria.

そして本発明の排ガス浄化制御装置の特徴は、内燃機関の排気経路に配置された本発明の排ガス浄化用触媒と、排ガス浄化用触媒の排ガス上流側に配置され触媒入ガス雰囲気に関連した物理量を検出する第１センサと、排ガス浄化用触媒の排ガス下流側に配置され触媒出ガス雰囲気に関連した物理量を検出する第２センサと、第１センサ及び第２センサの検出信号を受けて内燃機関の空燃比を制御する制御装置と、からなることにある。   The feature of the exhaust gas purification control apparatus of the present invention is that the exhaust gas purification catalyst of the present invention disposed in the exhaust path of the internal combustion engine, and the physical quantity related to the catalyst input gas atmosphere disposed on the exhaust gas upstream side of the exhaust gas purification catalyst. A first sensor for detecting, a second sensor for detecting a physical quantity related to the catalyst outgas atmosphere disposed on the exhaust gas downstream side of the exhaust gas purifying catalyst, and a detection signal from the first sensor and the second sensor, And a control device for controlling the air-fuel ratio.

本発明の排ガス浄化用触媒によれば、Rh領域の下流側に酸化領域を有しているので、Rh領域において生成したH2は酸化領域で酸化されるため、第２センサの出力急変点の変動を抑制することができる。したがって本発明の排ガス浄化制御装置によれば、第２センサの誤差を大きく縮小することができ、NOx の浄化率が向上するとともに空燃比制御の精度が向上する。また触媒の劣化の程度を把握する精度も向上する。 According to the exhaust gas purifying catalyst of the present invention, since the oxidation region is provided on the downstream side of the Rh region, H 2 generated in the Rh region is oxidized in the oxidation region. Variations can be suppressed. Therefore, according to the exhaust gas purification control apparatus of the present invention, the error of the second sensor can be greatly reduced, the NO x purification rate is improved, and the accuracy of air-fuel ratio control is improved. In addition, the accuracy of grasping the degree of deterioration of the catalyst is improved.

また本発明の触媒において、排ガス下流側より高温になりやすい排ガス上流側にPtとRhが担持された共存領域が形成されていれば、共存領域ではRhによってPtのシンタリングが抑制され活性の低下が抑制される。さらに、共存領域においてPtとRhとが合金化してRhの特性が低下したとしても、Rh領域に担持されているRhが十分な特性を発揮し、また共存領域を全長の４／10以下とし重量比で10≦Pt／Rh≦60の範囲とすれば、合金化するRhが少なくRhを効率よく活用することができる。   In the catalyst of the present invention, if a coexistence region in which Pt and Rh are supported is formed on the exhaust gas upstream side, which tends to be higher in temperature than the exhaust gas downstream side, Pt sintering is suppressed by Rh in the coexistence region and the activity is reduced. Is suppressed. Furthermore, even if Pt and Rh are alloyed in the coexistence region and the properties of Rh deteriorate, the Rh supported in the Rh region exhibits sufficient properties, and the coexistence region is 4/10 or less of the total length and weight. If the ratio is in the range of 10 ≦ Pt / Rh ≦ 60, Rh that is alloyed is small and Rh can be used efficiently.

本発明の排ガス浄化用触媒では、Rh領域の下流側にさらに酸化領域が形成されている。したがってリッチ雰囲気の排ガスが流入しRh領域における水蒸気改質反応の促進によってH2が生成しても、そのH2は酸化領域で酸化され第２センサにほとんど接触しない。したがって第２センサの出力急変点の変動を抑制することができ、第２センサの検出精度が向上する。これによりNOx の浄化率が向上するとともに空燃比制御の精度が向上する。また触媒の劣化の程度を把握する精度も向上する。 In the exhaust gas purifying catalyst of the present invention, an oxidation region is further formed on the downstream side of the Rh region. Therefore, even if exhaust gas in a rich atmosphere flows in and H 2 is generated by promoting the steam reforming reaction in the Rh region, the H 2 is oxidized in the oxidation region and hardly contacts the second sensor. Therefore, the fluctuation of the output sudden change point of the second sensor can be suppressed, and the detection accuracy of the second sensor is improved. As a result, the purification rate of NO x is improved and the accuracy of air-fuel ratio control is improved. In addition, the accuracy of grasping the degree of deterioration of the catalyst is improved.

Rh領域の触媒担持層におけるRhの担持量は、ハニカム基材１リットルあたり0.05〜５ｇとするのが好ましい。Rhの担持量がこの範囲より少ないと浄化性能が不十分となり、この範囲より多く担持しても効果が飽和しRhの有効利用が図れない。なお、Rh領域におけるRhの担持密度は、共存領域のRhの担持密度と異なっていてもよいが、製法上は共存領域と同一の担持密度とするのが便利である。   The amount of Rh supported in the catalyst support layer in the Rh region is preferably 0.05 to 5 g per liter of honeycomb substrate. If the loading amount of Rh is less than this range, the purification performance becomes insufficient, and even if the loading amount exceeds this range, the effect is saturated and Rh cannot be effectively used. The loading density of Rh in the Rh region may be different from the loading density of Rh in the coexistence region, but it is convenient to use the same loading density as that of the coexistence region in terms of manufacturing method.

酸化領域は、Rh領域より排ガス下流側であれば、その形成範囲は特に制限されないが、Rh領域より排ガス下流側の全体に形成することが望ましい。酸化領域には少なくとも酸化活性を有する触媒金属が担持されている。このような触媒金属としては、Pt、Pd、Ni、Coなどが例示されるが、Pt及びPdの少なくとも一種を用いるのが特に好ましい。この酸化領域には、酸化活性を損なわない範囲で他の貴金属あるいは卑金属を担持してもよい。   If the oxidation region is downstream of the exhaust gas from the Rh region, the formation range is not particularly limited, but it is desirable to form the entire oxidation region downstream of the Rh region. A catalytic metal having at least oxidation activity is supported in the oxidation region. Examples of such a catalyst metal include Pt, Pd, Ni, Co and the like, but it is particularly preferable to use at least one of Pt and Pd. This oxidation region may carry other noble metals or base metals as long as the oxidation activity is not impaired.

本発明の排ガス浄化用触媒は、Rh担持領域の排ガス上流側に、Rh及びPtを担持した共存領域を有することが望ましい。共存領域を有することにより、始動時などの低温の排ガスは、まだ層流とならない状態で排ガス流入側端面に衝突し、先ず共存領域を通過する。したがって排ガスの熱によって触媒が早期に昇温され、着火性に優れたPtが比較的早期に活性化温度に到達する。そして活性化温度に到達後は、反応熱によってさらに温度が上昇し、触媒の下流側での昇温も促進されるので、HC及びNOx の浄化性能が向上する。 The exhaust gas purifying catalyst of the present invention desirably has a coexistence region in which Rh and Pt are supported on the upstream side of the exhaust gas in the Rh support region. By having the coexistence region, the low temperature exhaust gas at the time of starting or the like collides with the end surface of the exhaust gas inflow side in a state where it is not yet laminar, and first passes through the coexistence region. Therefore, the temperature of the catalyst is raised early by the heat of the exhaust gas, and Pt having excellent ignitability reaches the activation temperature relatively early. After reaching the activation temperature, the temperature further rises due to the reaction heat, and the temperature rise on the downstream side of the catalyst is also promoted, so that the purification performance of HC and NO x is improved.

一方、共存領域が高温となっても、RhによってPtのシンタリングが抑制されるためPtの活性の低下が抑制され、耐久性が向上する。さらに、共存領域においてPtとRhとが合金化してRhの特性が低下したとしても、Rh領域に担持されたRhが十分な特性を発揮する。また共存領域は全長の４／10以下であるのが好ましい。このようにすることで合金化するRh量を少なくすることができ、高価なRhを効率よく用いることができる。共存領域を４／10を超えて形成すると、Ptと合金化するRhの割合が多くなり、HC及びNOx の浄化性能が不十分となる。共存領域は、排ガス流入側端面から形成してもよいが、排ガス流入側端面から５mmの範囲に担持された貴金属は、反応に寄与する割合が比較的小さいことがわかっているので、排ガス流入側端面から５mm以上下流側から共存領域を形成してもよい。 On the other hand, even if the coexistence region is at a high temperature, Rh suppresses Pt sintering, so that the decrease in Pt activity is suppressed and durability is improved. Furthermore, even if Pt and Rh are alloyed in the coexistence region and the properties of Rh are lowered, Rh supported in the Rh region exhibits sufficient properties. The coexistence region is preferably 4/10 or less of the entire length. By doing so, the amount of Rh to be alloyed can be reduced, and expensive Rh can be used efficiently. If the coexistence region is formed in excess of 4/10, the proportion of Rh alloyed with Pt increases, and the purification performance of HC and NO x becomes insufficient. The coexistence region may be formed from the end surface on the exhaust gas inflow side, but it is known that the precious metal supported in the range of 5 mm from the end surface on the exhaust gas inflow side has a relatively small contribution rate to the reaction. You may form a coexistence area | region from 5 mm or more downstream from an end surface.

なお共存領域を全長の４／10以下とした場合、酸化領域を全長の１／５以下とし、残部をRh領域とすることが特に望ましい。Rh領域がこれより短いとNOx の浄化性能が低下してしまう。酸化領域はH2を酸化する機能を有すれば足りるので、全長の１／５以下で十分である。 When the coexistence region is 4/10 or less of the total length, it is particularly desirable that the oxidation region is 1/5 or less of the total length and the rest is the Rh region. If the Rh region is shorter than this, the NO x purification performance is degraded. Since it is sufficient for the oxidation region to have a function of oxidizing H2, it is sufficient that it is 1/5 or less of the entire length.

共存領域では、Rhに対するPtの比率が重量比で10≦Pt／Rh≦60の範囲にあることが好ましく、15≦Pt／Rh≦50の範囲にあることが特に望ましい。RhとPtの比率がこの範囲より小さいと着火性が低下して低温時のHC浄化性能が低下し、この範囲より大きくなると高温時にPtのシンタリングが生じやすくなる。具体的には、共存領域におけるPtの担持量は、担体基材１リットルあたり 0.5〜40ｇとするのが好ましい。Ptの担持量がこの範囲より少ないと低温時の着火性に劣ってHC及びNOx の浄化性能が十分でなく、この範囲より多く担持しても効果が飽和するとともに高温時にPtのシンタリングが生じ易くなる。また共存領域におけるRhの担持量は、担持されているPtのシンタリングを抑制できるだけのRhが担持されていればよく、担体基材１リットルあたり0.05〜３ｇとするのが好ましい。Rhの担持量がこの範囲より少ないと高温時にPtのシンタリングが生じ易く、この範囲より多く担持しても効果が飽和しRhの有効利用が図れない。なお共存領域には、性能を損なわない範囲で他の貴金属あるいは卑金属を担持してもよいが、PtとRhのみを担持することが望ましい。 In the coexistence region, the ratio of Pt to Rh is preferably in the range of 10 ≦ Pt / Rh ≦ 60, and particularly preferably in the range of 15 ≦ Pt / Rh ≦ 50. If the ratio of Rh and Pt is smaller than this range, the ignitability is lowered and the HC purification performance at low temperatures is lowered. If the ratio is larger than this range, Pt sintering is likely to occur at high temperatures. Specifically, the amount of Pt supported in the coexistence region is preferably 0.5 to 40 g per liter of the carrier substrate. If the amount of Pt supported is less than this range, the ignitability at low temperatures is inferior and the purification performance of HC and NO x is not sufficient. It tends to occur. Further, the amount of Rh supported in the coexistence region is not limited as long as Rh capable of suppressing sintering of the supported Pt is supported, and is preferably 0.05 to 3 g per liter of the carrier substrate. If the loading amount of Rh is less than this range, sintering of Pt tends to occur at high temperatures, and even if the loading amount exceeds this range, the effect is saturated and effective use of Rh cannot be achieved. The coexistence region may carry other noble metals or base metals as long as the performance is not impaired, but it is desirable to carry only Pt and Rh.

本発明の排ガス浄化用触媒は、ペレット形状、ハニカム形状、フォーム形状などとすることができる。担体基体は、コージェライトなどの耐熱セラミックス製のもの、あるいは金属箔製のものを用いることができる。この担体基材に形成された複数のセルの内周表面あるいはその表面に、多孔質酸化物担体と貴金属とからなる触媒担持層が形成されている。   The exhaust gas purifying catalyst of the present invention can have a pellet shape, a honeycomb shape, a foam shape, or the like. The carrier substrate can be made of a heat-resistant ceramic such as cordierite or a metal foil. A catalyst support layer made of a porous oxide support and a noble metal is formed on the inner peripheral surface of the plurality of cells formed on the support substrate or on the surface thereof.

多孔質酸化物担体としては、 Al2O3、SiO2、ZrO2、CeO2、TiO2などの単種あるいは複数種、さらにはこれらの複数種の複合酸化物などから選択されたものを用いることができる。中でもCeO2を含むことが好ましい。CeO2の酸素吸放出能によって排ガス雰囲気の変動を抑制することができる。またCeO2−ZrO2複合酸化物を用いれば、Ptによって酸素吸放出能がさらに向上し、Rhによって生成する水素によってNOx 浄化性能がさらに向上する。 As the porous oxide carrier, one selected from a single type or a plurality of types such as Al 2 O 3 , SiO 2 , ZrO 2 , CeO 2 , TiO 2 , or a composite oxide of these multiple types is used. be able to. Of these, CeO 2 is preferably contained. The fluctuation of the exhaust gas atmosphere can be suppressed by the oxygen absorbing / releasing ability of CeO 2 . If CeO 2 —ZrO 2 composite oxide is used, oxygen absorption / release capability is further improved by Pt, and NO x purification performance is further improved by hydrogen generated by Rh.

触媒担持層の多孔質酸化物担体は、担体基材の全長で均一組成とするのが製法上好ましいが、場合によってはRh領域、酸化領域あるいは共存領域で異種の多孔質酸化物担体を用いることもできる。例えば共存領域と酸化領域においては Al2O3を用い、Rh領域においてはCeO2−ZrO2複合酸化物を用いれば、全ての領域において貴金属の特性がより高まるので、さらに浄化性能に優れた触媒とすることができる。 The porous oxide support of the catalyst support layer preferably has a uniform composition over the entire length of the support substrate, but in some cases, a different type of porous oxide support may be used in the Rh region, oxidation region, or coexistence region. You can also. For example, if Al 2 O 3 is used in the coexistence region and the oxidation region, and CeO 2 -ZrO 2 composite oxide is used in the Rh region, the characteristics of the noble metal are further enhanced in all regions, so that the catalyst has further excellent purification performance. It can be.

本発明の排ガス浄化制御装置は、本発明の排ガス浄化用触媒と、その排ガス上流側に配置され触媒入ガス雰囲気に関連した物理量を検出する第１センサと、排ガス浄化用触媒の排ガス下流側に配置され触媒出ガス雰囲気に関連した物理量を検出する第２センサと、第１センサ及び第２センサの検出信号を受けて内燃機関の空燃比を制御する制御装置と、から構成される。   The exhaust gas purification control apparatus of the present invention includes an exhaust gas purification catalyst of the present invention, a first sensor that is disposed upstream of the exhaust gas and detects a physical quantity related to the catalyst-inlet gas atmosphere, and an exhaust gas downstream of the exhaust gas purification catalyst. A second sensor that is disposed and detects a physical quantity related to the catalyst output gas atmosphere, and a control device that receives the detection signals of the first sensor and the second sensor and controls the air-fuel ratio of the internal combustion engine.

第１センサ及び第２センサとしては、従来用いられている A/Fセンサ、酸素センサなどを用いることができ、制御装置にはＥＣＵを用いることができる。少なくとも第２センサは、H2によって出力急変点が変動するものである。また制御装置の制御内容は、従来と同様でよい。本発明の排ガス浄化用触媒を用いることによって、リッチ空燃比で燃焼されたリッチ雰囲気の排ガス中においても、第２センサの出力急変点の変動を防止でき、精度の高い空燃比制御を行うことができる。 Conventionally used A / F sensors, oxygen sensors, and the like can be used as the first sensor and the second sensor, and an ECU can be used as the control device. At least the second sensor has a sudden output change point depending on H 2 . Further, the control content of the control device may be the same as the conventional one. By using the exhaust gas purifying catalyst of the present invention, it is possible to prevent fluctuations in the output sudden change point of the second sensor even in exhaust gas in a rich atmosphere burned at a rich air-fuel ratio, and to perform highly accurate air-fuel ratio control. it can.

以下、実施例及び比較例により本発明を具体的に説明する。   Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

（実施例１）
図１及び図２に本実施例の排ガス浄化用触媒を示す。この排ガス浄化用触媒は、多数の四角セルをもつ全長 130mm（L1）の円柱状のハニカム基材１と、セルの表面に形成された触媒担持層２とからなり、排ガス流入側端面から下流側へ20mm（L2）の範囲に共存領域20が形成され、共存領域20から排ガス流出側へ 100mmの範囲にRh領域21が形成され、Rh領域21から排ガス流出側端面までの10mm（L3）の範囲に酸化領域22が形成されている。 Example 1
1 and 2 show the exhaust gas purifying catalyst of this embodiment. This exhaust gas purifying catalyst is composed of a cylindrical honeycomb substrate 1 having a total length of 130 mm (L 1 ) having a large number of square cells and a catalyst support layer 2 formed on the surface of the cell, and is downstream from the end surface on the exhaust gas inflow side. A coexistence region 20 is formed in the range of 20 mm (L 2 ) to the side, an Rh region 21 is formed in the range of 100 mm from the coexistence region 20 to the exhaust gas outflow side, and 10 mm (L 3) from the Rh region 21 to the exhaust gas outflow side end surface ) Is formed in the oxidized region 22.

以下、この触媒の製造方法を説明し、構成の詳細な説明に代える。   Hereinafter, the method for producing the catalyst will be described, and the detailed description of the configuration will be substituted.

CeO2−ZrO2系固溶体粉末（モル比CeO2：ZrO2：Y2O3＝65：30：15） 120重量部と、活性アルミナ粉末80重量部と、アルミナバインダ（アルミナ水和物３重量部、40％硝酸アルミニウム水溶液44重量部）を適量の純水に混合し、ミリングしててスラリーを調製した。このスラリーを、コージェライト製で体積 1.1Ｌのハニカム基材１（600cpsi、壁厚75μｍ、全長 130mm、直径 103mm）にウォッシュコートした。その後、エアにて余分なスラリーを吹き払い、 120℃で乾燥後 650℃で３時間焼成して、ハニカム基材１のセル全面にコート層を形成した。コート層は、ハニカム基材１の１リットルあたり 210ｇ形成した。 CeO 2 —ZrO 2 solid solution powder (molar ratio CeO 2 : ZrO 2 : Y 2 O 3 = 65: 30: 15) 120 parts by weight, activated alumina powder 80 parts by weight, alumina binder (alumina hydrate 3 parts by weight) And 44 parts by weight of 40% aluminum nitrate aqueous solution) were mixed with an appropriate amount of pure water and milled to prepare a slurry. This slurry was wash coated on a honeycomb substrate 1 made of cordierite and having a volume of 1.1 L (600 cpsi, wall thickness 75 μm, total length 130 mm, diameter 103 mm). Thereafter, excess slurry was blown off with air, dried at 120 ° C., and fired at 650 ° C. for 3 hours to form a coat layer on the entire cell surface of the honeycomb substrate 1. The coating layer was formed in an amount of 210 g per liter of the honeycomb substrate 1.

次に、所定濃度のRhCl３ 水溶液にコート層全体（ハニカム基材１の全長）を浸漬して吸着担持し、 120℃で乾燥後500℃で１時間焼成してRhを担持した。Rhの担持量は、ハニカム基材１リットルあたり 0.4ｇである。   Next, the entire coating layer (the entire length of the honeycomb substrate 1) was immersed in an aqueous RhCl3 solution having a predetermined concentration and adsorbed and supported, dried at 120 ° C., and fired at 500 ° C. for 1 hour to support Rh. The amount of Rh supported is 0.4 g per liter of honeycomb substrate.

次いで所定濃度のPt(NO2)2(NH3)2水溶液の所定量を、排ガス流入側端面から下流側へ20mmの範囲のコート層に含浸させ、 120℃で乾燥後 650℃で３時間焼成してPtを担持した。これにより共存領域20が形成された。共存領域20におけるPtの担持量は、ハニカム基材１リットルあたり10ｇである。 Next, a predetermined amount of Pt (NO 2 ) 2 (NH 3 ) 2 aqueous solution with a predetermined concentration is impregnated into the coat layer in a range of 20 mm from the exhaust gas inflow side end face to the downstream side, dried at 120 ° C, and then fired at 650 ° C for 3 hours And supported Pt. As a result, a coexistence region 20 was formed. The amount of Pt supported in the coexistence region 20 is 10 g per liter of honeycomb substrate.

さらに所定濃度のPt(NO2)2(NH3)2水溶液の所定量を、排ガス流出側端面から上流側へ10mmの範囲のコート層に含浸させ、 120℃で乾燥後 650℃で３時間焼成してPtを担持した。これにより酸化領域22が形成された。酸化領域22におけるPtの担持量は、ハニカム基材１リットルあたり５ｇである。 Furthermore, a predetermined amount of Pt (NO 2 ) 2 (NH 3 ) 2 aqueous solution with a predetermined concentration is impregnated into the coat layer in the range of 10 mm from the exhaust gas outflow side end face to the upstream side, dried at 120 ° C, and fired at 650 ° C for 3 hours And supported Pt. As a result, an oxidized region 22 was formed. The amount of Pt supported in the oxidation region 22 is 5 g per liter of honeycomb substrate.

上記のように調製された実施例１の触媒を 2.4Ｌエンジンの直下に搭載し、図３に示す排ガス浄化制御装置とした。   The catalyst of Example 1 prepared as described above was mounted directly under the 2.4 L engine to obtain an exhaust gas purification control apparatus shown in FIG.

この排ガス浄化制御装置は、エンジン３と、エンジン３の排気管に配置された触媒コンバータ30と、触媒コンバータ30内に搭載された触媒31と、エンジン３と触媒コンバータ30との間に配置され触媒31への入ガスの A/F相当値を検出する A/Fセンサである第１センサ32と、触媒コンバータ30の下流側に配置され触媒31からの出ガス中の酸素濃度を検出する酸素センサである第２センサ33と、第１センサ32及び第２センサ33の検出信号が入力されその入力値に基づいてエンジン３の空燃比を制御する制御装置４と、から構成されている。   This exhaust gas purification control device includes an engine 3, a catalytic converter 30 disposed in the exhaust pipe of the engine 3, a catalyst 31 mounted in the catalytic converter 30, and a catalyst disposed between the engine 3 and the catalytic converter 30. The first sensor 32 that is an A / F sensor that detects the A / F equivalent value of the gas entering the gas 31 and the oxygen sensor that is disposed downstream of the catalytic converter 30 and detects the oxygen concentration in the gas discharged from the catalyst 31 And a control device 4 that receives the detection signals of the first sensor 32 and the second sensor 33 and controls the air-fuel ratio of the engine 3 based on the input values.

制御装置４の制御内容を図４に示す。エンジン３が始動されると、先ずステップ 100で第１センサ32が触媒入ガスの雰囲気を検出し、ステップ 101において入ガス雰囲気の A/Fのストイキからのずれが判定される。 A/Fが14.6±0.05のストイキ雰囲気である場合には何もせず処理はステップ 100へ戻るが、ストイキ雰囲気から14.6±0.05以上ずれている場合には、ステップ 102でリーン雰囲気であるかどうかが判定される。リーン雰囲気である場合には、ステップ 103で A/Fが14.6±0.05となるように燃料噴射量が制御され、処理はステップ 100へ戻る。リーン雰囲気でない場合は、触媒入ガスはリッチ雰囲気と判定され、ステップ 104で第２センサ33が触媒出ガスの酸素濃度を検出する。   The control contents of the control device 4 are shown in FIG. When the engine 3 is started, first, at step 100, the first sensor 32 detects the atmosphere of the catalyst input gas, and at step 101, the deviation of the input gas atmosphere from the A / F stoichiometry is determined. If the stoichiometric A / F is 14.6 ± 0.05, nothing is done and the process returns to step 100, but if it is deviated by more than 14.6 ± 0.05 from the stoichiometric atmosphere, whether or not the lean atmosphere is determined in step 102. Determined. If it is a lean atmosphere, the fuel injection amount is controlled so that the A / F becomes 14.6 ± 0.05 in step 103, and the process returns to step 100. If it is not a lean atmosphere, the catalyst input gas is determined to be a rich atmosphere, and in step 104, the second sensor 33 detects the oxygen concentration of the catalyst output gas.

ステップ 105では触媒出ガスがリッチ雰囲気であるか否かが判定され、リッチ雰囲気である場合にはステップ 103で A/Fが14.6±0.05となるように燃料噴射量が制御されてから、処理はステップ 100へ戻る。一方、リッチ雰囲気でない場合には、ステップ 106にて触媒31の積算使用時間、熱履歴などの記録が参照され、別に記憶されたマップに基づいて触媒が劣化しているか否かが判定される。   In step 105, it is determined whether or not the catalyst output gas has a rich atmosphere. If the atmosphere is rich, the fuel injection amount is controlled in step 103 so that the A / F becomes 14.6 ± 0.05, and then the process is performed. Return to step 100. On the other hand, if the atmosphere is not rich, in step 106, records such as the accumulated usage time and heat history of the catalyst 31 are referred to, and it is determined whether or not the catalyst has deteriorated based on a separately stored map.

そして触媒31が劣化していないと判定された場合には、処理はステップ 104に戻り、再び第２センサ33が触媒出ガスの酸素濃度を検出する。また触媒31が劣化していると判定された場合は、交換の表示をして注意を促し、ステップ 103で A/Fが14.6±0.05となるように燃料噴射量が制御されてから、処理はステップ 100へ戻る。   If it is determined that the catalyst 31 has not deteriorated, the process returns to step 104, and the second sensor 33 again detects the oxygen concentration of the catalyst output gas. Also, if it is determined that the catalyst 31 has deteriorated, the replacement is displayed to warn the attention, and after the fuel injection amount is controlled so that the A / F becomes 14.6 ± 0.05 in step 103, the processing is not performed. Return to step 100.

上記した排ガス浄化制御装置を用い、先ず、入ガス温度 950℃（触媒床温1000℃）にて 100時間の耐久処理を行った。耐久処理後、エンジン３を1600 rpm、排ガス流量10ｇ／秒の条件で運転し、第１センサ32の検出値によって判定されるエンジン３の空燃比の目標値を A/Fが14.8から14.4に切り替えた後の第２センサ33の出力値を経時で測定した。なお空燃比の制御は、図４に示す制御を行わず、図５に示すように目標値を A/Fが14.8又は14.4で一定となるようにした。結果を図５に示す。   Using the above-described exhaust gas purification control apparatus, first, an endurance treatment for 100 hours was performed at an inlet gas temperature of 950 ° C. (catalyst bed temperature of 1000 ° C.). After the endurance treatment, the engine 3 is operated at 1600 rpm and the exhaust gas flow rate is 10 g / second, and the target value of the air / fuel ratio of the engine 3 determined by the detection value of the first sensor 32 is switched from 14.8 to 14.4. After that, the output value of the second sensor 33 was measured over time. The air-fuel ratio control was not performed as shown in FIG. 4, but the target value was made constant at A / F of 14.8 or 14.4 as shown in FIG. The results are shown in FIG.

さらに、図４に示す制御を行いながら、60km／時間で定常走行し、その時のNOx エミッションを測定した。結果を表１に示す。 Furthermore, while performing the control shown in FIG. 4, the vehicle traveled at a steady speed of 60 km / hour, and NO x emission at that time was measured. The results are shown in Table 1.

（実施例２）
酸化領域22の貴金属をPtからPdに変更したこと以外は実施例１と同様の触媒を調製し、実施例１と同様にして第２センサ33の出力値と定常走行時のNOx エミッションを測定した。結果を図５及び表１に示す。 (Example 2)
A catalyst similar to that of Example 1 was prepared except that the noble metal in the oxidation region 22 was changed from Pt to Pd, and the output value of the second sensor 33 and NO x emission during steady running were measured in the same manner as in Example 1. did. The results are shown in FIG.

（比較例）
酸化領域22を形成しなかったこと、つまりRh領域21を排ガス流出側端面まで 110mmの範囲に形成したこと以外は実施例１と同様の触媒を調製し、実施例１と同様にして耐久処理後の第２センサ33の出力値と定常走行時のNOx エミッションを測定した。結果を図５及び表１に示す。 (Comparative example)
A catalyst similar to that of Example 1 was prepared except that the oxidation region 22 was not formed, that is, the Rh region 21 was formed within a range of 110 mm from the exhaust gas outlet side end surface. The output value of the second sensor 33 and the NO x emission during steady running were measured. The results are shown in FIG.

（従来例）
実施例１と同様にしてコート層が形成されたハニカム基材１を用意し、所定濃度のRhCl3 水溶液にコート層全体（ハニカム基材１の全長）を浸漬して吸着担持し、 120℃で乾燥後 500℃で１時間焼成してRhを担持した。Rhの担持量は、ハニカム基材１リットルあたり 0.4ｇである。次いで所定濃度のPt(NO2)2(NH3)2水溶液の所定量を全体に含浸させ、 120℃で乾燥後 650℃で３時間焼成してPtを担持した。Ptの担持量は、ハニカム基材１リットルあたり 1.5ｇである。 (Conventional example)
In the same manner as in Example 1, a honeycomb substrate 1 on which a coating layer was formed was prepared, and the entire coating layer (the entire length of the honeycomb substrate 1) was immersed in an aqueous RhCl 3 solution having a predetermined concentration and adsorbed and supported at 120 ° C. After drying, it was calcined at 500 ° C. for 1 hour to carry Rh. The amount of Rh supported is 0.4 g per liter of honeycomb substrate. Next, a predetermined amount of a Pt (NO 2 ) 2 (NH 3 ) 2 aqueous solution having a predetermined concentration was impregnated on the whole, dried at 120 ° C. and then calcined at 650 ° C. for 3 hours to carry Pt. The amount of Pt supported is 1.5 g per liter of honeycomb substrate.

この触媒を用いたこと以外は実施例１と同様にして、耐久処理後の第２センサ33の出力値と定常走行時のNOx エミッションを測定した。結果を図５及び表１に示す。 Except that this catalyst was used, the output value of the second sensor 33 after the endurance treatment and the NO x emission during steady running were measured in the same manner as in Example 1. The results are shown in FIG.

＜試験・評価＞   <Test and evaluation>

Figure 2006205134
Figure 2006205134

図５より、比較例では、実施例１〜２及び従来例に比べて第２センサ33の出力急変点が短時間側へ大きくシフトしている。すなわち比較例では、触媒入ガスがリッチに切り替わってから短い間に触媒でガスがリッチ雰囲気であると判定されることになる。したがって図４に示す制御では、早期にステップ 103の制御が行われて空燃比がストイキとなるため、従来例に比べてリッチ雰囲気の時間が短くなりNOx の浄化にとって不利となる。 From FIG. 5, in the comparative example, the sudden change point of the output of the second sensor 33 is greatly shifted to the short time side as compared with the first and second embodiments and the conventional example. That is, in the comparative example, it is determined that the gas is rich in the catalyst in a short time after the catalyst input gas switches to rich. In the control shown in FIG. 4, therefore, since early in control is performed in step 103 the air-fuel ratio becomes stoichiometric, time of rich atmosphere is disadvantageous for purifying shorter becomes NO x than the conventional example.

しかし実施例１〜２では、従来例に比べて第２センサ33の出力急変点のシフト量が小さく、しかも長時間側へのシフトとなっている。したがってステップ 105でリッチと判定されるまでの時間を十分確保することができ、NOx 浄化性能が向上する。そして表１より、比較例は実施例１〜２に比べてNOx エミッションが悪く、これは第２センサ33の出力急変点が短時間側へシフトしたことに起因していることが明らかである。 However, in the first and second embodiments, the shift amount of the output sudden change point of the second sensor 33 is smaller than that in the conventional example, and the shift is toward the long time side. Therefore, it is possible to secure a sufficient time until it is determined to be rich in step 105, and the NO x purification performance is improved. From Table 1, it is clear that the comparative example has worse NO x emission than Examples 1-2, and this is due to the fact that the output sudden change point of the second sensor 33 has shifted to the short time side. .

なお従来例において第２センサ33の出力急変点が実施例１〜２より短時間側へシフトし、NOx エミッションが比較例より悪化しているのは、耐久処理時にRhとPtとの合金化による劣化が生じたためと考えられる。 In the conventional example, the sudden change point of the output of the second sensor 33 is shifted to a shorter time than in Examples 1 and 2, and the NO x emission is worse than that of the comparative example. The alloying of Rh and Pt during the durability treatment This is thought to be due to the deterioration caused by.

本発明の一実施例の触媒の斜視図である。It is a perspective view of the catalyst of one Example of this invention. 本発明の一実施例の触媒の断面図である。It is sectional drawing of the catalyst of one Example of this invention. 本発明の一実施例の排ガス浄化制御装置のブロック図である。It is a block diagram of the exhaust gas purification control apparatus of one Example of this invention. 本発明の一実施例の排ガス浄化制御装置の制御内容を示すフローチャートである。It is a flowchart which shows the control content of the exhaust gas purification control apparatus of one Example of this invention. リーンからリッチへ切り替わったときの A/F値と第２センサ33の出力値との関係を示すタイムチャートである。6 is a time chart showing the relationship between the A / F value and the output value of the second sensor 33 when switching from lean to rich.

符号の説明Explanation of symbols

１：ハニカム基材 ２：触媒担持層 20：共存領域 21：Rh領域
22：酸化領域 ３：エンジン ４：制御装置 1: Honeycomb substrate 2: Catalyst support layer 20: Coexistence region 21: Rh region
22: Oxidation area 3: Engine 4: Controller

Claims (5)

排ガス流路をもつ担体基材と、該排ガス流路の表面に形成され多孔質酸化物担体と貴金属とを含んでなる触媒担持層と、を有する排ガス浄化用触媒であって、
該触媒担持層は、貴金属としてロジウムのみを担持したRh領域と、該Rh領域の排ガス下流側に形成され少なくとも酸化活性を有する触媒金属を担持した酸化領域と、を有することを特徴とする排ガス浄化用触媒。 An exhaust gas purifying catalyst comprising: a carrier substrate having an exhaust gas flow path; and a catalyst support layer formed on a surface of the exhaust gas flow path and including a porous oxide support and a noble metal,
The catalyst-carrying layer has an Rh region carrying only rhodium as a noble metal and an oxidation region formed on the exhaust gas downstream side of the Rh region and carrying a catalytic metal having at least an oxidation activity. Catalyst. 前記Rh担持領域の排ガス上流側における前記触媒担持層には、ロジウム及び白金を担持した共存領域を有する請求項１に記載の排ガス浄化用触媒。   The exhaust gas purifying catalyst according to claim 1, wherein the catalyst supporting layer on the exhaust gas upstream side of the Rh supporting region has a coexistence region supporting rhodium and platinum. 前記共存領域は前記担体基材の全長の４／10以下であり、ロジウムに対する白金の比率が重量比で10≦Pt／Rh≦60の範囲にある請求項２に記載の排ガス浄化用触媒。   3. The exhaust gas purifying catalyst according to claim 2, wherein the coexistence region is 4/10 or less of the total length of the carrier base material, and a ratio of platinum to rhodium is in a range of 10 ≦ Pt / Rh ≦ 60. 前記多孔質酸化物担体は少なくともセリアを含む請求項１に記載の排ガス浄化用触媒。   The exhaust gas purifying catalyst according to claim 1, wherein the porous oxide support contains at least ceria. 内燃機関の排気経路に配置された請求項１〜４のいずれかに記載の排ガス浄化用触媒と、該排ガス浄化用触媒の排ガス上流側に配置され触媒入ガス雰囲気に関連した物理量を検出する第１センサと、該排ガス浄化用触媒の排ガス下流側に配置され触媒出ガス雰囲気に関連した物理量を検出する第２センサと、該第１センサ及び該第２センサの検出信号を受けて該内燃機関の空燃比を制御する制御装置と、からなることを特徴とする排ガス浄化制御装置。
An exhaust gas purifying catalyst according to any one of claims 1 to 4 disposed in an exhaust path of an internal combustion engine, and a physical quantity associated with a catalyst input gas atmosphere disposed on an exhaust gas upstream side of the exhaust gas purifying catalyst. 1 sensor, a second sensor that is disposed on the exhaust gas downstream side of the exhaust gas purification catalyst and detects a physical quantity related to the catalyst outgas atmosphere, and receives the detection signals of the first sensor and the second sensor, and the internal combustion engine An exhaust gas purification control device comprising: a control device for controlling the air-fuel ratio of the exhaust gas.
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CA002595717A CA2595717A1 (en) 2005-01-31 2006-01-19 Catalyst for purifying exhaust gases and exhaust-gas purification controller using the same
EP06701445A EP1841529A1 (en) 2005-01-31 2006-01-19 Catalyst for purifying exhaust gases and exhaust-gas purification controller using the same
CN200680003588XA CN101111309B (en) 2005-01-31 2006-01-19 Catalyst for purifying exhaust gases and exhaust-gas purification controller using the same
US11/883,444 US20090124494A1 (en) 2005-01-31 2006-01-19 Catalyst For Purifying Exhaust Gases and Exhaust-Gas Purification Controller Using the Same
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009226249A (en) * 2008-03-19 2009-10-08 Cataler Corp Exhaust gas cleaning catalyst
US8323579B2 (en) 2007-05-18 2012-12-04 Toyota Jidosha Kabushiki Kaisha S storage catalyst and exhaust-gas converting apparatus
WO2020008981A1 (en) * 2018-07-05 2020-01-09 株式会社キャタラー Exhaust gas purification catalyst device
US11154842B2 (en) 2016-03-09 2021-10-26 Cataler Corporation Exhaust gas purification underfloor catalyst and catalyst system

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7870724B2 (en) 2004-11-09 2011-01-18 Ford Global Technologies, Llc Lean NOx trap with PGM zoned axially
JP4760625B2 (en) * 2006-09-06 2011-08-31 マツダ株式会社 Exhaust gas purification catalyst device
US7718150B2 (en) * 2007-04-17 2010-05-18 Ford Global Technologies, Llc Reverse platinum group metal zoned lean NOx trap system and method of use
DE102011100017A1 (en) * 2011-04-29 2012-10-31 Süd-Chemie AG Process for the preparation of zoned catalysts
CN111263661B (en) * 2017-10-27 2023-05-30 株式会社科特拉 Exhaust gas purifying device using metal base material and method for manufacturing same

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6178438A (en) * 1984-09-21 1986-04-22 Toyota Motor Corp Monolithic catalyst for purifying exhaust gas
JPS62125856A (en) * 1985-11-27 1987-06-08 Toyota Motor Corp Exhaust gas purifying monolith catalyst
JPS6384635A (en) * 1986-09-26 1988-04-15 Nissan Motor Co Ltd Catalyst for purifying exhaust gas
US20040082470A1 (en) * 2002-10-24 2004-04-29 Gandhi Haren S. Catalyst system for lean burn engines
JP2007521953A (en) * 2004-02-11 2007-08-09 ユミコア・アクチエンゲゼルシャフト・ウント・コムパニー・コマンディットゲゼルシャフト Exhaust gas purification catalyst having a noble metal concentration changing in the axial direction, and method for producing the catalyst

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU604083B2 (en) * 1987-01-20 1990-12-06 Nippon Shokubai Kagaku Kogyo Co. Ltd. Catalyst for purifying exhaust gas and method for production thereof
JP3327054B2 (en) * 1995-06-07 2002-09-24 トヨタ自動車株式会社 Exhaust gas purification catalyst
JP2006075724A (en) * 2004-09-09 2006-03-23 Toyota Motor Corp Catalyst for exhaust gas cleaning

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6178438A (en) * 1984-09-21 1986-04-22 Toyota Motor Corp Monolithic catalyst for purifying exhaust gas
JPS62125856A (en) * 1985-11-27 1987-06-08 Toyota Motor Corp Exhaust gas purifying monolith catalyst
JPS6384635A (en) * 1986-09-26 1988-04-15 Nissan Motor Co Ltd Catalyst for purifying exhaust gas
US20040082470A1 (en) * 2002-10-24 2004-04-29 Gandhi Haren S. Catalyst system for lean burn engines
JP2007521953A (en) * 2004-02-11 2007-08-09 ユミコア・アクチエンゲゼルシャフト・ウント・コムパニー・コマンディットゲゼルシャフト Exhaust gas purification catalyst having a noble metal concentration changing in the axial direction, and method for producing the catalyst

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8323579B2 (en) 2007-05-18 2012-12-04 Toyota Jidosha Kabushiki Kaisha S storage catalyst and exhaust-gas converting apparatus
JP2009226249A (en) * 2008-03-19 2009-10-08 Cataler Corp Exhaust gas cleaning catalyst
US11154842B2 (en) 2016-03-09 2021-10-26 Cataler Corporation Exhaust gas purification underfloor catalyst and catalyst system
WO2020008981A1 (en) * 2018-07-05 2020-01-09 株式会社キャタラー Exhaust gas purification catalyst device
JP2020006301A (en) * 2018-07-05 2020-01-16 株式会社キャタラー Exhaust gas purification device
US11352924B2 (en) 2018-07-05 2022-06-07 Cataler Corporation Exhaust gas purification catalyst device
JP7245613B2 (en) 2018-07-05 2023-03-24 株式会社キャタラー Exhaust gas purification catalyst device

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