JP5051393B2 - Exhaust purification device - Google Patents

Exhaust purification device Download PDF

Info

Publication number
JP5051393B2
JP5051393B2 JP2008327857A JP2008327857A JP5051393B2 JP 5051393 B2 JP5051393 B2 JP 5051393B2 JP 2008327857 A JP2008327857 A JP 2008327857A JP 2008327857 A JP2008327857 A JP 2008327857A JP 5051393 B2 JP5051393 B2 JP 5051393B2
Authority
JP
Japan
Prior art keywords
catalyst
catalyst layer
exhaust
cdpf
nox
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.)
Active
Application number
JP2008327857A
Other languages
Japanese (ja)
Other versions
JP2010150962A (en
Inventor
均一 岩知道
Original Assignee
三菱自動車工業株式会社
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 三菱自動車工業株式会社 filed Critical 三菱自動車工業株式会社
Priority to JP2008327857A priority Critical patent/JP5051393B2/en
Publication of JP2010150962A publication Critical patent/JP2010150962A/en
Application granted granted Critical
Publication of JP5051393B2 publication Critical patent/JP5051393B2/en
Application status is Active legal-status Critical
Anticipated expiration legal-status Critical

Links

Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection
    • Y02A50/20Air quality improvement or preservation
    • Y02A50/23Emission reduction or control
    • Y02A50/234Physical or chemical processes, e.g. absorption, adsorption or filtering, characterised by the type of pollutant
    • Y02A50/2351Atmospheric particulate matter [PM], e.g. carbon smoke microparticles, smog, aerosol particles, dust
    • Y02A50/2352Atmospheric particulate matter [PM], e.g. carbon smoke microparticles, smog, aerosol particles, dust the particulate matter coming from a source on-board a vehicle, e.g. removed by diesel particulate filters [DPF]

Description

  The present invention relates to an exhaust emission control device.

  An automobile equipped with a diesel engine is equipped with an exhaust purification device including a diesel particulate filter (DPF) in order to reduce particulate matter in exhaust gas, so-called particulate matter (PM).

  The DPF includes a catalyst-supporting type (PM purification) that is configured so that noble metal is contained in the catalyst layer supported on the particulate filter, and combustion of PM trapped on the particulate filter during general traveling can be promoted. With function) there is a diesel particulate filter (hereinafter referred to as CDPF). In CDPF, noble metals are thermally deteriorated due to thermal endurance, so that the PM combustion ability at low temperatures is lowered, and the exhaust purification performance may be lowered. In this case, the desired PM combustion capacity can be exhibited when the CDPF temperature is in a certain high temperature region, for example, 550 ° C., but in general driving in a diesel vehicle, the CDPF temperature is such a high temperature. It is rare to become an area. For this reason, it is necessary to perform forced combustion in which PM deposited on the CDPF is forcibly burned by injecting fuel, which causes deterioration of fuel consumption.

Therefore, in order to improve the PM combustion capacity of CDPF, a CDPF catalyst layer containing an alkali metal is known (for example, see Patent Document 1).
JP 2007-83114 A (Claim 1, FIG. 4, etc.)

  In view of the fact that potassium (K) as an alkali metal easily binds to silicon (Si) in the support, that is, easily moves to the support, CDPF described in Patent Document 1 uses soda as a clathrate material in the catalyst layer. Light is added to suppress the movement of K to the carrier. However, since sodalite is added, there is a problem that catalyst preparation is complicated and cost is high.

  Accordingly, an object of the present invention is to eliminate the problems of the prior art, and to provide an exhaust purification device that is easy to prepare a catalyst and has high exhaust purification performance.

The exhaust purification device of the present invention is arranged such that a first catalyst layer containing potassium (K) is supported on a metal carrier having an acute angle portion, and is disposed downstream of the NOx storage reduction exhaust purification catalyst. And a particulate filter in which a second catalyst layer is supported on a filter that captures particulate matter in the exhaust, and the first catalyst layer is supported to have a maximum thickness at the acute angle portion. The NOx occlusion reduction exhaust purification catalyst is configured to disperse the potassium (K) in accordance with an increase in the thermal load of the NOx occlusion reduction exhaust purification catalyst and adhere to the second catalyst layer. To do.

In the present invention, since the first catalyst layer containing K in the NOx trap catalyst is supported on the metal carrier, K is scattered on the particulate filter and adheres to the second catalyst layer. The low K can be stably held by the particulate filter, and the exhaust gas purification performance of the particulate filter is improved. In this case, the particulate filter does not need to contain a clathrate material such as sodalite, so the effect of K can be obtained and the catalyst can be easily prepared. The particulate filter in the present invention refers to a catalyst-supporting particulate filter.
The basic component of the second catalyst layer is Al 2 O 3 , and the content of Al 2 O 3 is preferably 1 to 40 g / L with respect to the carrier volume.

  The catalyst component of the second catalyst layer is preferably palladium (Pd). When the nitric oxide (NO) -carbon monoxide (CO) reaction at a low temperature in the presence of K contains Pd that is higher than Pt, the combustion efficiency of PM can be further increased.

  The amount of potassium (K) added to the first catalyst layer is preferably 15 to 30 g / L with respect to the carrier volume so that a sufficient amount of K is scattered in the downstream particulate filter.

  The catalyst component of the second catalyst layer of the particulate filter is palladium (Pd) and platinum (Pt), and in this case, the ratio of Pd and Pt is preferably 1: 1 to 1: 5. When the addition amount is within this range, the exhaust purification performance can be suitably exhibited with K adhering to the particulate filter.

  According to the exhaust emission control device of the present invention, an excellent effect of high exhaust purification performance can be achieved.

  The exhaust emission control device of this embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram showing a configuration of an internal combustion engine including an exhaust purification device according to the present embodiment.

  A multi-cylinder diesel engine (hereinafter simply referred to as an engine) 11 mounted on a vehicle includes a cylinder 13, and a piston 14 is accommodated in the cylinder 13 so as to be reciprocally movable. An intake pipe 15 is connected to the cylinder head of the cylinder 13. An exhaust pipe (exhaust passage) 16 is further connected to the cylinder head. A turbocharger 17 is provided in the middle of the intake pipe 15 and the exhaust pipe 16.

  When exhaust gas flows from the engine 11 into the turbocharger 17, the turbocharger 17 rotates the turbine by the flow of the exhaust gas, and the compressor rotates along with the rotation of the turbine, and the turbocharger 17 enters the turbocharger 17 from the intake pipe 15. Air is sucked and pressurized. The air pressurized by the turbocharger 17 is supplied to the intake port of the engine 11 via the intake pipe 15.

  In the present embodiment, a diesel oxidation catalyst (hereinafter simply referred to as an oxidation catalyst) 18 that is an exhaust purification catalyst is provided in the exhaust pipe 12 on the downstream side of the turbocharger 17, and the exhaust purification apparatus 10 of the present embodiment is provided downstream thereof. Is provided. The exhaust gas purification apparatus 10 includes a NOx trap catalyst 19 and a CDPF 20 arranged in order from the upstream side. A known oxidation catalyst can be used as the oxidation catalyst 18.

  The NOx trap catalyst 19 will be described with reference to FIGS. FIG. 2 is a partial cross-sectional schematic view of a metal carrier used for the NOx trap catalyst, and FIG. 3 is a partial cross-sectional schematic view of a catalyst layer of the NOx trap catalyst.

The NOx trap catalyst 19 traps NOx in the exhaust gas as nitrate X-NO 3 when the exhaust air-fuel ratio is a lean air-fuel ratio, and traps when the exhaust air-fuel ratio in which a large amount of reducing component is present is the stoichiometric air-fuel ratio or the rich air-fuel ratio. It is an exhaust purification catalyst having an excellent function of releasing NOx that has been reduced and reducing it to N 2 . The NOx trap catalyst 19 includes a configured metal carrier 21 and a catalyst layer 22 supported on the metal carrier 21.

  As shown in FIGS. 2 and 3, the metal carrier 21 constituting the NOx trap catalyst 19 is formed of, for example, a plate material formed by laminating a SUS flat plate 23 a and a corrugated plate 23 b to form a large number of cells 24. Is formed. The catalyst layer 22 is supported on the wall surface of each cell 24.

The catalyst layer 22 includes at least one selected from Pt, Pd, and Rh as a catalyst component (noble metal component). Further, the catalyst layer 22, as a base component includes a base component of the known catalyst, preferably alumina (Al 2 O 3) as a base component. The noble metal component preferably contains Pt and Pd. The content of the catalyst component in the catalyst layer 22 is preferably 0.1 g / L to 10 g / L, more preferably 0.5 g / L to 5 g / L with respect to the carrier volume. If it is less than 0.1 g / L, the amount of catalyst is too small to perform NOx purification. On the other hand, if it exceeds 10 g / L, it is too much to aggregate Pt and not only improve the catalyst performance. The catalyst cost is unsuitable. The content of the base material component is preferably 10 g / L to 400 g / L, more preferably 50 g / L to 300 g / L, relative to the carrier volume.

  K that functions as a NOx trapping agent is added to the catalyst layer 22. In particular, by using K, it is possible to improve the NOx purification performance as compared to Ba and to widen the temperature range of the catalyst. Further, use of K increases resistance to sulfur (S) poisoning.

  The effect of the addition of K will be described in detail with reference to FIGS.

  FIG. 4 is a result of an experiment for showing that NOx purification efficiency is improved by adding K, and a NOx trap catalyst to which K is added (the same as the NOx trap catalyst of the present embodiment) and a NOx trap to which Ba is added. It is a graph which shows the NOx purification efficiency with respect to a catalyst and each catalyst inlet_port | entrance temperature. As shown in FIG. 4, when K is added, the NOx purification efficiency is higher in most temperature ranges than when Ba is added. In particular, when Ba is added at 400 ° C. or more, the NOx purification efficiency is reduced, but when K is added, it is not reduced. Therefore, it can be seen that if K is added as the NOx trapping agent, the NOx purification efficiency is high and the temperature range that can be purified is wide.

  FIG. 5 shows experimental results for showing resistance to S. When K is added (the same as the NOx trap catalyst of this embodiment) and when Ba is added, each NOx trap catalyst is changed to an electron probe micro. It is the figure observed with the analyzer (EPMA). The endurance conditions for S poison are fuel: S concentration of 300 ppm-wt, catalyst temperature: maintained at 550 ° C., engine state: excess oxygen, endurance time: 7 hours. In the S poison regeneration, the catalyst temperature is 700 ° C., the engine state is excessive fuel, and the regeneration time is 10 minutes.

  As shown in FIG. 5, after S poisoning and after S poison regeneration, K or Ba remained in the catalyst layer both when K was added and when Ba was added. However, in the case of K addition, the S poisoning is less than in the case of Ba addition, and after the S poisoning regeneration, unlike the case of Ba addition, S hardly remains in the catalyst layer. . Therefore, it can be seen that the addition of K as a NOx trapping agent can further suppress S poisoning and improve S poisoning regeneration.

  Therefore, in the present embodiment, K is added to the catalyst layer 22 as a NOx trapping agent to expand the exhaust gas purification temperature range and improve S poisoning resistance.

  In the present embodiment, in the exhaust purification device 10, in addition to improving the NOx purification performance of the NOx trap catalyst 19 using K for the NOx trap catalyst 19 disposed on the upstream side, K is used as the CDPF 20 on the downstream side. The PM combustion performance of the CDPF 20 is improved by being scattered and adhered (trapped) to the CDPF 20.

  That is, in a carrier made of a ceramic material such as cordierite, K is bonded to and moved by Si in cordierite at a high temperature. However, in this embodiment, a metal carrier 21 made of SUS or the like is used, and therefore the metal carrier 21 is used. And K are not bound to each other, and K is likely to scatter to the CDPF 20 on the downstream side.

  In this case, conventionally, it was difficult to support K in the CDPF catalyst layer because K contained in the CDPF catalyst layer was easily bonded to Si in the support. By causing the scattered K to adhere to the catalyst layer of the CDPF 20, the PM combustibility is further improved.

  As described above, conventionally, K is not scattered, but in the present embodiment, the catalyst layer to which K is added is supported on the metal carrier to extend the travel distance of the vehicle, that is, the heat of the NOx trap catalyst 19. As the load increases, K is scattered to adhere to the downstream CDPF 20 to improve the exhaust purification performance of the NOx trap catalyst 19 and the CDPF 20. In this case, not all K scatters and adheres to the CDPF 20 on the downstream side, and a certain amount is kept in the NOx trap catalyst 19.

  Here, the scattering of K will be described with reference to FIG. FIG. 6 shows a NOx trap catalyst using the metal carrier (the same as the NOx trap catalyst of the present embodiment) and a NOx trap catalyst using the cordierite carrier (the catalyst layer configuration is the same as that of the present embodiment) 850. It is an experimental result which shows the residual amount of K after carrying out heat endurance (aging) at 64 degreeC. In FIG. 6, the vertical axis indicates the K amount (%), and the initial carrying amount is 100.

  In the case of a NOx trap catalyst using a cordierite carrier, the amount of movement to the carrier is 40% or more, but in the case of a NOx trap catalyst using a metal carrier, there is no amount of movement to the carrier. Then, the remaining amount in the catalyst is increased correspondingly, and the scattering amount is increased. Therefore, in the case of a NOx trap catalyst using a metal carrier, K does not bind to the carrier, and a large amount of K can be scattered. Therefore, in this embodiment, a catalyst layer is carried on the metal carrier, and K is A large amount is scattered.

  The amount of K added is preferably 5 g / L to 40 g / L, more preferably 15 g / L to 30 g / L, relative to the carrier volume. If the amount is less than 5 g / L, the amount of addition is too small to often exhibit the desired effect in the downstream CDPF 20, and if it is more than 40 g / L, the amount of addition in the catalyst is too large and the oxidation performance of the NOx trap catalyst 19 is high. Is not suitable because it significantly decreases.

  When K is added to the NOx trap catalyst 19, it is preferable to further add zeolite in order to keep this K stable. In this case, known zeolites such as A-type zeolite, X-type zeolite, and Y-type zeolite can be used as the zeolite, and it is particularly preferable to use Y-type zeolite. Zeolite is preferably contained in an amount of 5 to 30 g / L based on the carrier volume. If it is less than 5 g / L, the amount added in the catalyst is too small to contribute to the stability of K. On the other hand, if it exceeds 30 g / L, the oxidation performance of the NOx trap catalyst 19 is lowered, which is not suitable.

Furthermore, in this embodiment, the base material contains magnesia (MgO), ceria (CeO 2 ) , and titania (TiO 2 ) as additives. By containing MgO, large pores can be provided in the catalyst layer 22 at the time of catalyst firing, whereby the exhaust gas can diffuse to the deep part of the catalyst layer 22. In this case, the added MgO has an average particle diameter of 0.1 μm to 3.0 μm before catalyst firing, and, for example, pores of about 1 μm to 10 μm are formed in the catalyst layer 22 by firing. . Thus, by increasing the pores by adding MgO, the diffusion of the exhaust gas can be promoted, and the purification performance can be improved. The content of MgO is preferably 0.5 g / L to 10 g / L, more preferably 2 g / L to 5 g / L with respect to the carrier volume. If the amount is less than 0.5 g / L, a large number of pores cannot be provided, so that the diffusibility of the exhaust gas is not sufficient. If the amount is more than 10 g / L, the adhesion of the catalyst layer 22 to the metal carrier 21 decreases. This is because the catalyst layer 22 is easily peeled off.

When Pt is contained as a catalyst component, the decrease in the activity of Pt is suppressed by further containing CeO 2 . The content of CeO 2 is preferably 10 g / L to 100 g / L, more preferably 15 g / L to 40 g / L with respect to the carrier volume. This is because if the amount is less than 10 g / L, the decrease in Pt activity cannot be suppressed, and if the amount is more than 100 g / L, the adhesion of the catalyst layer 22 to the metal carrier 21 is lowered and the catalyst layer 22 is easily peeled off.

The amount of suppressing TiO 2 the S poisoning is preferably 1 g / 50 g / L with respect to the support volume. If it is less than 1 g / L, the amount added in the catalyst is too small to contribute to the suppression of S poisoning, and if it is more than 50 g / L, the amount added in the catalyst is too large to support the catalyst layer 22. This is because the adhesiveness to 21 is lowered and the catalyst layer 22 is easily peeled off.

  The CDPF 20 disposed on the downstream side of the NOx trap catalyst 19 will be described below with reference to FIG. FIG. 7 is an enlarged schematic cross-sectional view for explaining a CDPF catalyst layer. In the CDPF 20, a catalyst layer 26 is supported on a particulate filter 25 for capturing PM. Examples of the particulate filter 25 include a known filter made of ceramic, for example, cordierite or silicon carbide (SiC). Even if the particulate filter 25 contains Si, in the present embodiment, most of the K adheres to the catalyst layer 26, and therefore the amount of Si and K in the particulate filter 25 is extremely small.

The catalyst layer 26 includes at least one selected from Pt, Pd, and Rh as a noble metal component. Further, the catalyst layer 26, as a base component includes a base component of the known catalyst, preferably as the base component comprises Al 2 O 3. K scattered from the upstream NOx trap catalyst 19 adheres to the base material component. Al 2 O 3 is particularly susceptible to K adhesion.

  The adhesion of K with CDPF will be described with reference to FIG. FIG. 8 shows an observation result of providing a CDPF having the same base material as that of the present embodiment on the downstream side of the NOx trap catalyst 19, aging the CDPF, and observing a cross section with EPMA. In FIG. 8, the white portion is K, and the higher the K concentration, the stronger the white. As shown in FIG. 8, K was not present in the catalyst layer before aging, but K was present in the catalyst layer after aging. Therefore, even in the CDPF 20 of the present embodiment using the same base material, K scattered from the upstream NOx trap catalyst 19 is captured by the catalyst layer of the CDPF 20. Thereby, K can be substantially stably held in the CDPF 20, and as a result, PM combustibility is improved.

  The point which PM combustibility improves because scattered K adheres to the catalyst layer 26 of CDPF20 is demonstrated using FIG. FIG. 9 is an experimental result showing CDPF after K deposition, CDPF before K deposition, and the respective carbon (carbon, C) combustion temperatures. As shown in FIG. 9, the C combustion temperature was about 400 ° C. after K deposition, but was about 550 ° C. before K deposition. This is probably because oxygen (O) in the exhaust gas is attracted by the strong electron donating action of K and reacts well with O in PM accumulated in the DPF 20 to improve combustibility. Therefore, when K adheres to the catalyst layer 26, the C combustion temperature is lowered, that is, the PM combustibility is improved.

  Note that the PM combustibility does not decrease until K is scattered from the upstream NOx trap catalyst 19 as the thermal load of the NOx trap catalyst 19 increases. That is, in the present embodiment, the scattering of K starts from the vicinity where the PM combustibility decreases due to the deterioration of the downstream CDPF 20, and the PM combustibility of the CDPF 20 is intended to be improved by the K scattering.

  As the catalyst component, it is particularly preferable to contain Pd. This is because Pd has a higher NO-CO reaction at a low temperature in the presence of K than Pt. That is, in the present embodiment, K is scattered from the upstream NOx trap catalyst 19, so that even in this case, Pd is included as a catalyst component so as not to lower the PM combustion performance of the downstream CDPF 20. It is preferable.

Here, as long as Pd is contained, Pt may further be contained. In this case, the ratio of Pd to Pt is preferably 0.2 to 0.5. When the ratio of Pd is less than 0.2, improvement in NOx purification performance by NO-CO reaction cannot be expected, and when it is more than 0.5, PM combustion performance by C-nitrogen dioxide (NO 2 ) reaction is not achieved. It is unsuitable because it drops.

Further, Rh may be added to the catalyst layer 26 in order to further improve the NOx purification performance. The content of the catalyst component in the catalyst layer 26 is preferably 0.1 g / L to 15 g / L, more preferably 0.5 g / L to 5 g / L with respect to the carrier volume. If the amount is less than 0.1 g / L, the amount of catalyst is too small to perform PM combustion or oxidation of carbon monoxide (CO) or hydrocarbon (HC). On the other hand, if the amount exceeds 15 g / L, the amount of catalyst This is not suitable because the cost is too high. The content of Al 2 O 3 is preferably 1 g / L to 40 g / L, more preferably 4 g / L to 20 g / L with respect to the carrier volume.

When Pt is contained as a noble metal component, the decrease in the activity of Pt can be suppressed by further containing CeO 2 . Further, TiO 2 may be added to suppress S poisoning.

  When the exhaust gas purification apparatus 10 including the NOx trap catalyst 19 and the CDPF 20 formed in this way is measured for the combustion temperature of PM while aging, as shown in FIG. Although the combustion temperature rises, it is difficult to reach 550 ° C. However, in the case of the conventional example described in conjunction with FIG. 10, the PM combustion temperature exceeds 550 ° C. after a certain period of time. In other words, exhaust purification performance is improved by using the exhaust purification device 10 of the present embodiment.

Examples of the method for preparing the catalyst are as follows. The slurry of the catalyst layer 22 and the catalyst layer 26 is adjusted, respectively. Specifically, a water-soluble salt of a noble metal as a catalyst component, a base material component, a water-soluble salt of K, and optionally zeolite, MgO, CeO 2 and TiO 2 are dissolved / dispersed in water. Wet pulverize to prepare a slurry for the catalyst layer 22. Similarly, the slurry for the catalyst layer 26 is prepared by dissolving / dispersing a water-soluble salt of a noble metal as a catalyst component, a base component, and optionally CeO 2 and TiO 2 in water, and wet-pulverizing the solution / dispersion. To do. Then, the carrier is immersed in each slurry, and excess slurry is removed, followed by drying and firing, whereby the catalyst layer 22 and the catalyst layer 26 are formed as a single unit. The drying temperature is preferably 100 ° C to 250 ° C, and the firing temperature is preferably 350 ° C to 650 ° C.

  The exhaust purification device of the present invention is applied to the exhaust passage of a diesel engine and used for exhaust purification of the diesel engine, but can also be provided in the exhaust passage of a direct injection gasoline engine. In this embodiment, the diesel oxidation catalyst 18 is also provided in the exhaust passage, but it may not be provided.

  The exhaust purification catalyst of the present invention can be used, for example, in an exhaust purification device such as an automobile. Therefore, it can be used in the automobile manufacturing industry.

1 is a schematic configuration diagram of an internal combustion engine including an exhaust purification device according to the present embodiment. It is a partial cross section schematic diagram for demonstrating the metal carrier used for the NOx trap catalyst which concerns on this embodiment. It is an expanded sectional schematic diagram for demonstrating the catalyst layer of the NOx trap catalyst which concerns on this embodiment. It is a graph which shows that NOx purification efficiency improves by K addition. It is the EPMA observation result which shows the tolerance with respect to S. It is a graph which shows the residual amount of K for every support | carrier. It is an expanded sectional schematic diagram for demonstrating the catalyst layer of CDPF concerning this embodiment. It is an EPMA observation result explaining that K adheres to the same catalyst layer as CDPF. It is a graph which shows C combustion temperature of CDPF after K adhesion and before K adhesion. It is a graph which shows PM combustion start temperature with respect to heat endurance time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Exhaust purification apparatus 11 Engine 12 Exhaust pipe 13 Cylinder 14 Piston 15 Intake pipe 16 Exhaust pipe 17 Turbocharger 18 Diesel oxidation catalyst 19 NOx trap catalyst 20 CDPF
21 Metal carrier 22 Catalyst layer 23a Flat plate 23b Corrugated plate 24 Cell 25 Particulate filter 26 Catalyst layer

Claims (5)

  1. A NOx occlusion reduction exhaust purification catalyst in which a first catalyst layer containing potassium (K) is supported on a metal carrier having an acute angle portion, and a particulate matter in the exhaust gas disposed downstream of the NOx occlusion reduction exhaust purification catalyst the second catalyst layer on the filter to capture a particulate filter carrying a,
    The first catalyst layer is supported to have a maximum thickness at the acute angle portion, and the NOx storage reduction exhaust purification catalyst increases the heat load of the NOx storage reduction exhaust purification catalyst with the potassium (K). The exhaust emission control device is configured to be scattered according to the above and attached to the second catalyst layer .
  2. 2. The exhaust gas according to claim 1 , wherein the basic component of the second catalyst layer is Al 2 O 3 , and the content of Al 2 O 3 is 1 to 40 g / L with respect to the carrier volume. Purification equipment.
  3. The exhaust emission control device according to claim 1 or 2, wherein the catalyst component of the second catalyst layer is palladium (Pd).
  4. The exhaust emission control device according to any one of claims 1 to 3, wherein an addition amount of potassium (K) in the first catalyst layer is 15 to 30 g / L with respect to the carrier volume.
  5. The second catalyst layer of the particulate filter is characterized in that the catalyst component contains palladium and (Pd) platinum (Pt), and the ratio of Pd to Pt is 1: 1 to 1: 5. The exhaust emission control device according to any one of claims 1 to 4 .
JP2008327857A 2008-12-24 2008-12-24 Exhaust purification device Active JP5051393B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008327857A JP5051393B2 (en) 2008-12-24 2008-12-24 Exhaust purification device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2008327857A JP5051393B2 (en) 2008-12-24 2008-12-24 Exhaust purification device

Publications (2)

Publication Number Publication Date
JP2010150962A JP2010150962A (en) 2010-07-08
JP5051393B2 true JP5051393B2 (en) 2012-10-17

Family

ID=42570330

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2008327857A Active JP5051393B2 (en) 2008-12-24 2008-12-24 Exhaust purification device

Country Status (1)

Country Link
JP (1) JP5051393B2 (en)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4539809B2 (en) * 2001-09-13 2010-09-08 三菱自動車工業株式会社 Exhaust purification device
JP4333160B2 (en) * 2003-02-24 2009-09-16 トヨタ自動車株式会社 Exhaust gas purification system for internal combustion engine
JP4438957B2 (en) * 2005-06-13 2010-03-24 三菱自動車工業株式会社 Exhaust gas purification device for internal combustion engine
JP2008151100A (en) * 2006-12-20 2008-07-03 Toyota Motor Corp Exhaust emission control device

Also Published As

Publication number Publication date
JP2010150962A (en) 2010-07-08

Similar Documents

Publication Publication Date Title
JP6315717B2 (en) Exhaust gas purification device
US9789443B2 (en) Filter substrate comprising three-way catalyst
KR20170142154A (en) Particulate filter with hydrogen sulphide block function
RU2668191C2 (en) Positive ignition engine and exhaust system comprising catalysed zone-coated filter substrate
JP2020008022A (en) Pollutant reduction equipment for gasoline vehicles
JP6416098B2 (en) Catalytic soot filter
CA2796830C (en) Gasoline engine emissions treatment systems having particulate filters
JP5753167B2 (en) Oxygen storage catalyst with low ceria reduction temperature
JP2018159380A (en) Exhaust system for vehicular positive ignition internal combustion engine
JP5854995B2 (en) Gasoline engine exhaust gas treatment system
EP2501464B1 (en) Zoned catalyzed soot filter
JP2013099748A (en) Pressure-balanced, catalyzed exhaust article
US8844274B2 (en) Compact diesel engine exhaust treatment system
JP6312210B2 (en) Internal combustion engine exhaust gas purification method
US20170043322A1 (en) NOx TRAP
Fino et al. Open issues in oxidative catalysis for diesel particulate abatement
US8057768B2 (en) Device for the purification of diesel exhaust gases
EP2324904B1 (en) Catalyst-carrying filter and exhaust gas purification system
US8640440B2 (en) Removal of particulates from the exhaust gas of internal combustion engines operated with a predominantly stoichiometric air/fuel mixture
JP4682151B2 (en) Exhaust gas purification catalyst
US7998424B2 (en) Exhaust system comprising zoned oxidation catalyst
JP5869202B2 (en) Diesel exhaust gas treatment system catalyst monitoring
ES2688995T3 (en) Enhanced catalyzed soot filter
EP1789161B1 (en) Catalytically coated particle filter and method for producing the same and its use
JP4835193B2 (en) Diesel particulate filter

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20110204

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20120113

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20120118

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20120319

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20120627

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20120710

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20150803

Year of fee payment: 3