JP2008264631A - Filter catalyst for purifying exhaust gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter catalyst for purifying an exhaust gas which increases the amount of tolerance accumulation of particulates to the filter diaphragm to reduce the frequency of regeneration treatment without worsening the fuel consumption. <P>SOLUTION: The filter catalyst for purifying the exhaust gas is comprised of a ceramic honeycomb structure and provided with a gas inflow aperture, a gas effluence aperture, a filter body to divide the gas inflow aperture and the gas effluence aperture and to have the filter diaphragm acting a filter upon gas circulation, a sub-diaphragm to separate at least the gas effluent aperture to a plurality of sub-apertures and an exhaust gas purification layer formed on the surface of the sub-diaphragm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exhaust gas purifying filter catalyst. More specifically, the present invention relates to a wall flow type diesel exhaust gas purification filter catalyst that collects and processes particulates (particulate matter) contained in exhaust gas of a diesel engine or the like.

  NOx and particulate matter are problems in environmental pollution by exhaust gas from diesel engines. This particulate is a fine particle substance, and is mainly composed of solid carbon fine particles (SOOT) and organic solvent soluble matter (SOF). As such a particulate processing means, a ceramic plugged honeycomb body (diesel particulate filter (hereinafter referred to as DPF)) is known. The DPF defines a gas inflow hole plugging the opening at the downstream end of the cell of the ceramic honeycomb structure, a gas outflow hole plugging the opening at the upstream end of the cell, and a gas inflow hole and a gas outflow hole. In addition, it has a filter partition wall that serves as a filter during gas flow, and suppresses particulate discharge by filtering exhaust gas through the pores of the filter partition wall and collecting particulates in the filter partition wall. .

  However, in the DPF, the pressure loss increases depending on the volume of the particulates, so it is necessary to periodically remove and regenerate the particulates deposited by some means.

  Conventionally, when pressure loss increases, DPF is regenerated by burning particulates accumulated by a burner or an electric heater. However, in this case, as the volume of the particulates increases, the temperature at the time of combustion rises, and the DPF may be damaged by the thermal stress caused thereby.

  Therefore, in recent years, a continuous regeneration type DPF has been developed in which a coating layer is formed of alumina or the like on the cell partition of the DPF, and a catalytic metal made of a noble metal such as platinum (Pt) is supported on the coating layer.

  As such a continuously regenerating filter, there has been proposed an exhaust gas purifying filter catalyst in which catalyst metal is supported in pores formed on the surface or inside of a filter partition wall, and particulates are introduced into the pores and burned. (See Patent Document 1). In such an exhaust gas purifying filter catalyst, the catalyst is uniformly supported on the surface of the pores of the partition walls of the filter. Therefore, the particulates are burned in the pores and efficiently removed.

  However, the exhaust gas purifying filter catalyst described above has a smaller total coating amount than the conventional filter in which the coat layer is formed on the surface of the filter partition and the catalyst is supported. . Therefore, more particulates are collected than particulates removed by combustion, and the particulates gradually accumulate, which may inhibit the passage of exhaust gas through the filter partition walls and increase the pressure loss of the filter. .

For this reason, when the amount of accumulated particulates reaches a predetermined amount, DPF regeneration processing is required in which the accumulated particulates are forcibly burned by adding fuel to the exhaust gas by post-injection or light oil spray. This DPF regeneration treatment is performed by controlling the bed temperature of the exhaust gas purifying filter catalyst at 600 to 650 ° C., but the catalyst is uniformly supported on the pore surfaces of the filter partition walls. Is completely burned and the calorific value is increased. Further, the exhaust gas purifying filter catalyst has a high heat receiving efficiency due to the wall flow type structure in which the heat generated by the combustion passes through the inside of the cell wall. For this reason, when the amount of accumulated particulates is large, there is a possibility that heat accumulation increases and breaks due to thermal stress. Therefore, it is necessary to suppress the accumulation amount of particulates and to burn them frequently, which also contributes to deterioration of fuel consumption due to an increase in regeneration frequency.
JP-A-9-94434

  The present invention has been made to solve the above-described problem, and increases the allowable accumulation amount of particulates on the filter partition walls, thereby reducing the frequency of regeneration processing and causing no deterioration in fuel consumption. It is an object to provide a filter catalyst for purification.

  The filter catalyst for purification of exhaust gas of the present invention is a ceramic honeycomb structure, and is a filter that partitions a gas inflow hole, a gas outflow hole, the gas inflow hole and the gas outflow hole, and serves as a filter for gas circulation It has a filter main body having a partition, a sub partition that divides at least a gas outflow hole into a plurality of sub holes, and an exhaust gas purification layer formed on the surface of the sub partition.

  In the exhaust gas purifying filter catalyst of the present invention, the exhaust gas purifying layer may include an oxidation catalyst layer composed of a porous oxide and an oxidation catalyst.

  Further, in the exhaust gas purifying filter catalyst of the present invention, the sub partition wall may be formed by dividing the substantially quadrangular cross section of the gas outflow hole into two substantially in a letter shape or four in a substantially cross shape.

The exhaust gas purifying filter catalyst of the present invention has a gas inflow hole having an inlet end opened and an outlet end plugged, and a gas outflow having an inlet end plugged and an outlet end opened with respect to an exhaust gas flow. A wall flow type exhaust gas purifying filter catalyst that has a hole, a gas partition hole that divides the gas inflow hole and the gas outflow hole, and serves as a filter for gas flow. A formed sub-partition is provided. Particulates in the exhaust gas flowing into the gas inflow hole are collected by the filter partition wall and are deposited on or inside the filter partition wall. The collected particulates are burned by the regeneration process, but since the exhaust gas purification layer is not formed on the filter partition wall, incomplete combustion that generates CO ₂ gas and CO gas occurs on the filter partition wall. For this reason, the calorific value at the time of particulate combustion is small, and the temperature rise of the exhaust gas purifying filter catalyst is low. The CO gas generated by the incomplete combustion passes through the filter partition wall and enters the gas outflow hole, and flows out along the sub partition wall provided in the gas outflow hole. At this time, since the CO gas comes into contact with the oxidation catalyst of the exhaust gas purification layer formed in the sub partition wall, it becomes CO ₂ gas by its catalytic action. The reaction heat generated by this oxidation reaction is hardly released to the outside together with the exhaust gas and is not stored in the sub partition wall, so the exhaust gas purification filter catalyst is not overheated. Therefore, a larger amount of particulates than conventional can be deposited on the filter partition wall, and as a result, the frequency of the DPF regeneration process can be reduced. That is, it is possible to avoid damage to the exhaust gas purification filter catalyst due to the DPF regeneration process and to suppress deterioration in fuel consumption.

  A preferred embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 schematically shows the configuration of the exhaust gas purifying filter catalyst of the present invention. (A) is the fragmentary sectional view of the filter catalyst for exhaust gas purification of this invention, (b) is the fragmentary top view which looked at the filter catalyst for exhaust gas purification from the exhaust gas entrance side (A view), (c) is It is the partial top view seen from the waste gas exit side (B view).

  The exhaust gas purifying filter catalyst 10 of the present invention includes a filter body 12, a sub partition wall 14, and an exhaust gas purification layer 16 formed on the sub partition wall 14.

  The filter body 12 is a porous ceramic honeycomb structure, and includes a gas inflow hole 18, a gas outflow hole 20, and a filter partition wall 22 that divides these and serves as a filter for gas flow. Here, the porous ceramic honeycomb structure is composed of a honeycomb-shaped cell composite having a cell diameter of about 1 mm to 2.5 mm, and each cell of the cell composite is surrounded by a filter partition wall 22. Is formed. The filter partition has a wall thickness of about 0.15 mm to 0.5 mm.

  The gas inflow hole 18 is a cell hole serving as an inlet when the exhaust gas G enters the filter main body 12, and the cell upstream end located upstream in the exhaust gas flow direction is open, and the cell located downstream of the exhaust gas. This is a cell hole whose downstream end is plugged and closed. The gas outflow hole 20 is a cell hole that becomes an outlet of the exhaust gas G when the exhaust gas G flows through the filter body 12, and is a cell hole in which the cell upstream end is plugged and closed, and the cell downstream end is opened. . The exhaust gas G that has entered the filter main body 12 from the gas inflow hole 18 passes through the filter partition wall 22, and the exhaust gas from which the particulates have been filtered is discharged from the gas outflow hole 20.

The filter body 12 can be made of heat resistant ceramics. Specifically, a commercially available porous honeycomb ceramic DPF can be used, and as a raw material, a heat-resistant ceramic raw material such as cordierite or SiC that is generally used can be used. Here, in order to perform good exhaust gas purification, the cell density composed of the gas inflow holes 18 and the gas outflow holes 20 is preferably 31.0 cells / cm ² or more.

  The sub partition 14 is a partition that divides at least the gas outflow hole 20 of the filter main body 12 into a plurality of sub holes 20a, and extends substantially parallel to the gas outflow hole 20 toward the cell downstream end. For this reason, the sub-partition wall 14 is not significantly involved in pressure loss and does not have a large particulate collection ability.

  When the cross section of the gas outflow hole 20 of the filter main body 12 is substantially rectangular and the gas outflow hole 20 is divided into two or four by the sub partition wall 14, the gas inflow resistance when the gas flows into the filter main body 12 is increased excessively. The sub-partition wall 14 can be provided without any problem, and its thickness is preferably about 50 to 300 μm.

  In the exhaust gas purification filter catalyst 10 of the present invention, the exhaust gas purification layer 16 carrying the oxidation catalyst is formed only on the sub partition 14, and such an exhaust gas purification layer is not formed on the filter partition 22.

  The filter partition wall 22 has pores (not shown) that serve as gas flow paths when gas flows inside and / or on the surface thereof. The size of the pores is not particularly limited, but in order to introduce the particulates into the pores and collect the particulates in the pores, the pores should be large enough to allow the particulates to flow. . Specifically, the average particle size of the particulates is 10 to 30 nm, and the particulates are usually connected in a straight chain, so that the pore size is preferably larger than this, and 20 to 40 μm. It should be about.

  The exhaust gas purification layer formed on the surface of the sub partition wall 14 has an oxidation catalyst layer made of a porous oxide and an oxidation catalyst.

The porous oxide is an oxide having a large specific surface area. For example, an oxide such as Al ₂ O ₃ , ZrO ₂ , CeO ₂ , TiO ₂ , SiO ₂ , zeolite, or a composite oxide composed of a plurality of these is used. Can be used.

  The oxidation catalyst only needs to promote the oxidation of the particulates by catalytic reaction, and one or more selected from noble metals such as Pt, Rh, and Pd and metals such as Ag, Cu, Fe, Ni, Co, and Mn. Seeds can be used. Among these, noble metals such as Pt, Rh, and Pd are preferable.

  The exhaust gas purification layer preferably includes at least the porous oxide and the oxidation catalyst, but may be a layer containing various exhaust gas purification components represented by NOx adsorbent, NOx occlusion reduction catalyst, and the like. The exhaust gas purification layer may be a single layer by mixing these exhaust gas purification components, or may be a multilayer of two or more layers in which each exhaust gas purification component is formed in separate layers.

  Next, the operation of the exhaust gas purifying filter catalyst 10 of the present invention will be described with reference to FIG. FIG. 2 is a partial cross-sectional schematic diagram for explaining the operation of the exhaust gas purifying filter catalyst 10 of the present invention. In the filter partition wall 22, the particulates P are deposited.

  Particulates P in the exhaust gas G flowing into the gas inflow hole 18 from the cell upstream end of the filter body 12 are collected by the filter partition wall 22 and accumulated on the surface of the gas inflow hole 18 of the filter partition wall 22 or in the filter partition wall. Since no oxidation catalyst layer (exhaust gas purification layer) is formed on the filter partition wall 22, the amount of particulate P deposited on the filter partition wall 22 gradually increases. When the accumulation of particulates reaches a predetermined amount (when the differential pressure becomes a predetermined value or more), fuel is added to the exhaust gas by post injection or light oil spraying, so that the accumulated particulate P is forcibly burned. .

However, since the exhaust gas purification layer supporting the oxidation catalyst is not formed on the filter partition wall 22 as described above, the particulate P cannot be completely burned and burns incompletely to generate CO ₂ gas and CO gas. Arise. The incomplete combustion gas g containing the CO ₂ gas and the CO gas passes through the pores of the filter partition wall 22 and flows into the gas outlet hole 20, and contacts the sub partition wall 14 while flowing through the gas outlet hole 20. Circulate in the direction. Since the exhaust gas purification layer 16 carrying the oxidation catalyst is formed on the sub-partition wall 14, the CO gas in the incomplete combustion gas is brought into contact with the oxidation catalyst 16, so that the oxidation is promoted and becomes CO ₂ gas. The gas is discharged from the gas outlet 20 into the atmosphere.

  That is, the calorific value due to incomplete combustion on the surface and inside of the filter partition 22 is smaller than the calorific value due to complete combustion with catalytic action, and only CO gas generated by incomplete combustion is catalyzed in the sub-partition. Since it is oxidized, its calorific value is small. Therefore, since the collected particulates are completely burned in two stages, the amount of heat generated by the combustion is dispersed, and an increase in the bed temperature of the exhaust gas purifying filter catalyst can be suppressed. In this way, when the amount of particulates accumulated is the same, the bed temperature during the regeneration process can be lowered by using the exhaust gas purification filter catalyst of the present invention as compared with the conventional exhaust gas purification filter catalyst. . In other words, if the bed temperature during regeneration is the same, the exhaust gas purification filter catalyst of the present invention can deposit more particulates on the filter partition wall than the conventional exhaust gas purification filter catalyst. is there. That is, the exhaust gas purifying filter catalyst of the present invention can increase the particulate regeneration limit amount (also referred to as particulate deposition allowable limit amount).

  Hereinafter, the exhaust gas purification filter catalyst of the present invention will be described in more detail with reference to Examples and Comparative Examples.

<Filter catalyst for exhaust gas purification>
(Example)
The exhaust gas purifying filter catalyst of the present embodiment has a filter body and a sub partition wall that divides the gas outflow hole of the filter body into four crosses, and an oxidation catalyst layer is formed on the sub partition wall.

As a material of the filter body, a cordierite porous ceramic honeycomb structure having a cross section of 160 mm and a length of 100 mm was used. This porous ceramic honeycomb structure has a volume of 2 liters, a porosity of 65%, a cell density of 46.5 cells / cm ² , a cell downstream end of the cell hole serving as the gas inflow hole, and a cell of the cell hole serving as the gas outflow hole. The upstream end is sealed with a plug made of the same material as the filter body to form a filter body.

  The gas outflow hole has a quadrangular cross section, and is divided into four in a cross shape by a sub partition wall, and is divided into sub holes having a square cross section with one side of the cell being 0.5 mm. The gas inflow hole has a square cross section and a cell diameter of 1.2 mm. The wall thickness of the filter partition wall is 0.3 mm, and the wall thickness of the sub partition wall is 0.15 mm.

The exhaust gas purification layer contains Al ₂ O ₃ having an average particle diameter of 1 μm as a porous oxide and carries Pt as an oxidation catalyst. The exhaust gas purification layer (oxidation catalyst layer) is formed on the surface of the sub partition wall, but is not formed on the filter partition wall.

  The exhaust gas purifying filter catalyst of this example as described above was produced as follows.

First, a slurry containing 20% by mass of Al ₂ O ₃ powder having an average particle size of 0.5 μm and 5% by mass of a binder such as alumina sol was prepared. Next, the slurry was immersed in this slurry so that the exhaust gas inflow end side of the filter main body was on the upper side in the vertical direction. In this way, the slurry was adhered to the filter partition wall and the sub partition wall surface of the gas outflow hole. Thereafter, the filter main body was taken out of the slurry, and the slurry adhering to the filter partition by suction from the gas outflow hole side of the filter main body was removed by suction air from the gas inflow hole. At this time, since air flows through the gas outflow holes along the surface of the sub partition wall, the slurry adhering to the sub partition wall remains on the surface of the sub partition wall. Thereafter, the filter main body was dried at 250 ° C., and further fired at 500 ° C. for 30 minutes to form a porous oxide layer for supporting the oxidation catalyst on the surface of the sub partition wall.

Subsequently, the filter main body in which the porous oxide layer was formed on the sub-partition was immersed in a nitric acid aqueous solution containing dinitrodiamine platinum, and Pt was supported on the porous oxide layer on the surface of the sub-partition. Then, in the same manner as described above, the aqueous solution containing dinitrodiamine platinum impregnated in the filter partition wall was removed by suction from the gas outlet hole side of the filter body. In this way, the filter main body in which Pt is supported only on the sub-partition is dried at 250 ° C. and further calcined at 500 ° C. for 30 minutes to have the oxidation catalyst layer supporting Pt on the surface of the sub-partition. A filter catalyst was obtained. The sub-partition of the filter catalyst of the example obtained in this way holds 30 g of Al ₂ O ₃ per liter of the filter body, and the amount of Pt supported in the oxidation catalyst layer is the volume of the filter body. It was 0.5 g per liter.

(Comparative example)
The exhaust gas purifying filter catalyst of this comparative example is a conventional exhaust gas purifying filter catalyst, and an exhaust gas purifying layer containing an oxidation catalyst is formed on the filter partition wall of the filter body.

As a material of the filter body, a cordierite porous ceramic honeycomb structure having a cross section of 160 mm and a length of 100 mm was used. This porous ceramic honeycomb structure has a volume of 2 liters, a porosity of 65%, a pore size of 10 to 100 μm, a cell density of 46.5 cells / cm ² , a cell downstream end of a cell hole serving as a gas inflow hole, The cell upstream end of the cell hole serving as the outflow hole is sealed with a plug made of the same material as the filter main body to form a wall flow type filter main body. In addition, the sub partition is not provided. Further, the gas inflow hole and the gas outflow hole have a square cross section and a cell diameter of 1.2 mm, and the wall thickness of the filter partition wall is 0.3 mm.

The exhaust gas purification layer contains Al ₂ O ₃ having an average particle diameter of 0.5 μm as a porous oxide and carries Pt as an oxidation catalyst. This exhaust gas purification layer is formed on the surface of the filter partition and the surface of the internal pores.

The exhaust gas purification layer holds 0.5 g of Pt per liter of the filter body, and the filter partition wall holds 30 g of Al ₂ O ₃ per liter of the filter body.

  The exhaust gas purifying filter catalyst of this comparative example as described above was manufactured as follows.

First, a slurry containing 20% by mass of Al ₂ O ₃ powder having an average particle size of 0.5 μm and 5% by mass of a binder such as alumina sol is prepared, and this slurry is sucked from the gas inlet hole side of the filter body to filter partition walls. Was impregnated with an Al ₂ O ₃ slurry. Thereafter, the filter body was taken out of the slurry and further sucked from the gas outflow hole side of the filter body to remove excess slurry. Subsequently, the filter main body was dried at 250 ° C., and further fired at 500 ° C. for 30 minutes to form a porous oxide layer that supports the oxidation catalyst on the surface and inside of the filter partition wall.

  Subsequently, an aqueous nitric acid solution containing 9% by mass of Pt powder was impregnated from the inflow hole side of the filter body on which the porous oxide layer was formed, and Pt was supported on the porous oxide layer inside and on the surface of the filter partition wall. . Then, it dried at 250 degreeC, and also baked for 30 minutes at 500 degreeC, and obtained the filter catalyst for exhaust gas purification of the comparative example which has an exhaust gas purification layer on the surface and inside of a filter partition.

<Particulate combustion test>
Particulate combustion tests were performed using the exhaust gas purifying filter catalysts of the above-mentioned Examples and Comparative Examples, and the allowable particulate deposition limit amounts capable of performing DPF regeneration without damaging the honeycomb structure were determined.

  First, for each of the exhaust gas purifying filter catalysts of Examples and Comparative Examples, five levels of test filter catalysts were prepared by changing the amount of particulates deposited. In addition, the particulate deposit amount of each sample filter catalyst was changed by changing the particulate collection time.

  Next, as shown in FIG. 3, an exhaust gas purification apparatus 50 was obtained by arranging a straight flow type oxidation catalyst 30 upstream of the obtained filter catalyst 10. The straight flow type oxidation catalyst 30 is usually used as an oxidation catalyst for a diesel engine of a passenger car. Here, 18461-0R030 (capacity: 1.3 L, Pt: 3 g / L) was used. The exhaust gas purification device 50 was installed on the exhaust side of the diesel engine, and an exhaust gas G of about 300 ° C. was introduced. At this time, the operating conditions of the engine were: rotation speed: 2000 rpm, torque: 100 N · m, intake air amount (Ga): 40 g / s. Then, when the temperature on the outlet side p1 of the oxidation catalyst 30 reached 300 ° C., the light oil spray 40 was started. The light oil spray amount was set to a constant value. When the sprayed light oil is combusted by the oxidation catalyst 30 and the bed temperature of the test filter catalyst 10 (measured at the point p2 in FIG. 3) reaches 700 ° C., the light oil spray 40 is stopped and the operating condition is set to the idle condition (engine Rotational speed: 700 rpm, torque: 0 N · m, Ga = 12 g / s). During this time, the temperature change at the point p3 in the vicinity of the outflow side of the test filter catalyst 10 was measured to obtain the maximum temperature Tmax generated by the combustion of the particulates, and the test filter catalyst was taken out and visually checked for damage.

  FIG. 4 shows the relationship between the particulate deposition amount obtained in this way, the maximum temperature Tmax, and the crack generation limit. Here, ◯ indicates that no crack was observed by visual inspection after the particulate combustion test, and × indicates that a crack was observed.

  It can be seen from FIG. 4 that the maximum temperature Tmax (° C.) increases in proportion to the particulate deposition amount M. The results obtained with the test filter catalyst of the example are indicated by a solid line I, and the results obtained with the test filter catalyst of the comparative example are indicated by a broken line II. That is, if the particulate deposition amount is the same, it can be seen that the maximum temperature Tmax (° C.) of the solid line I is lower than the maximum temperature Tmax (° C.) of the broken line II. In the graph of FIG. 4, the allowable particulate deposition limit M is shown as a ratio where the allowable particulate deposition limit of the comparative example is 1.

  In this test, the allowable particulate deposition limit of the example was 1.4. That is, the exhaust gas purifying filter catalyst of the embodiment can deposit 1.4 times the particulates of the conventional exhaust gas purifying filter catalyst and can reduce the regeneration frequency thereof, so that the fuel efficiency is higher than that of the conventional exhaust gas purifying filter catalyst. Can be improved.

  The exhaust gas purifying filter catalyst of the present invention is not limited to the above-described embodiment, and may be changed without departing from the gist of the present invention. For example, in the above embodiment, the sub partition is provided perpendicular to the side of the gas outflow hole having a substantially square cross section, but may be provided in a diagonal line as shown in FIG. FIG. 5 is a partial plan view of the exhaust gas purification filter catalyst as viewed from the exhaust gas outflow side, and the same parts as those in FIG. By providing the sub partition wall 14 on the diagonal line of the gas outflow hole 20, the rigidity of the honeycomb structure can be increased. Moreover, you may provide the sub-partition which has an exhaust gas purification layer also in a gas inflow hole similarly to a gas outflow hole.

  The exhaust gas purifying filter catalyst of the present invention is suitable as a wall flow type exhaust gas purifying filter catalyst that collects and processes particulates contained in exhaust gas such as diesel engines.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the filter catalyst for exhaust gas purification of this invention, (a) is a fragmentary sectional view, (b) is the partial top view which looked at the exhaust gas purification filter catalyst from the exhaust gas containing side (A view), (C) is the partial top view seen from the waste gas exit side (B view). It is a partial cross-sectional schematic diagram explaining the effect | action of the filter catalyst 10 for exhaust gas purification of this invention. It is the schematic explaining the structure of the apparatus for exhaust gas purification used for the particulate combustion test. It is a graph which shows the relationship between the amount of particulate deposits, and catalyst bed temperature. It is the fragmentary top view seen from the waste gas exit side which shows the other aspect of a sub partition.

Explanation of symbols

10: Exhaust gas purification catalyst 12: Filter body 14: Sub partition 16: Exhaust gas purification layer (oxidation catalyst layer) 18: Gas inflow hole 20: Gas outflow hole 22: Filter partition 30: Straight flow type oxidation catalyst 40: Fuel injection 50 : Exhaust gas purification device

Claims (3)

A ceramic honeycomb structure having a gas inflow hole, a gas outflow hole, a filter main body having a filter partition wall that divides the gas inflow hole and the gas outflow hole and serves as a filter during gas flow;
A sub-partition dividing at least the gas outflow hole into a plurality of sub-holes;
An exhaust gas purification filter catalyst comprising an exhaust gas purification layer formed on a surface of the sub partition wall.   The exhaust gas purification layer catalyst according to claim 1, wherein the exhaust gas purification layer includes an oxidation catalyst layer made of a porous oxide and an oxidation catalyst.   3. The exhaust gas purifying filter catalyst according to claim 1, wherein the sub-partition wall divides a substantially square cross section of the gas outflow hole into two substantially in a letter shape or four in a substantially cross shape.

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