JP5330044B2 - Oxidation catalyst equipment for exhaust gas purification - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxidation catalyst device for purifying an exhaust gas which can oxidize and fire particulates in the exhaust gas under lower temperature and in a shorter time. <P>SOLUTION: The oxidation catalyst device 1 for purifying the exhaust gas is provided with a porous filter substrate 2 and a catalyst carried by the porous filter substrate 2 wherein the porous filter substrate 2 is equipped with an influent cell 4, effluent cell 5 and cell septum 6. The catalyst consists of a first catalyst layer 3a carried by the surface of the influent cell 4 side of the cell septum 6 and a second catalyst layer carried by the surface of the wall face of the pore 7 of the cell septum 6. The particulates in the exhaust gas are oxidized and purified by the catalyst. The catalyst is represented by general formula: Y<SB>1-x</SB>Ag<SB>x</SB>Mn<SB>1-y</SB>Ti<SB>y</SB>O<SB>3</SB>, and consists of a composite metal oxide wherein 0.01&le;x&le;0.30 and 0.005&le;y&le;0.30 and a porous material which is a mixture with zirconium oxide. The catalyst layers 3a, 3b are comprised of a porous material equipped with a pore of which the diameter is 0.01-3.0 &mu;m and the porosity of the whole of the porous filter substrate 2 and the catalyst layers 3a, 3b is 30-55 vol%. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an oxidation catalyst device for exhaust gas purification that purifies particulates contained in exhaust gas of an internal combustion engine by oxidizing and burning them using a catalyst made of a composite metal oxide.

  Conventionally, an oxidation catalyst device for exhaust gas purification using a catalyst made of a perovskite-type composite metal oxide to oxidize, burn, and purify particulates and hydrocarbons contained in exhaust gas of an internal combustion engine is known.

  As the oxidation catalyst device for exhaust gas purification, a porous filter substrate having a wall flow structure in which one end portion is an exhaust gas inflow portion and the other end portion is an exhaust gas outflow portion, and is supported on the porous filter substrate. (For example, refer to Patent Document 1).

  The porous filter base material having the wall flow structure includes a plurality of inflow cells in which an exhaust gas inflow portion is opened and an exhaust gas outflow portion is blocked among a plurality of through holes formed to penetrate in the axial direction. The exhaust gas inflow portions of the plurality of through holes are closed and the exhaust gas outflow portions are opened, and the inflow cells and the cell partition walls separating the outflow cells are provided. On the other hand, the catalyst includes a first catalyst layer supported on the surface of the cell partition wall on the inflow cell side, and a second catalyst layer supported on a wall surface forming pores of the porous filter substrate. Consists of.

  According to the oxidation catalyst device for exhaust gas purification, the particulate matter in the exhaust gas is oxidized by the catalyst while the exhaust gas of the internal combustion engine flowing in from the exhaust gas inflow portion is circulated to the outflow cell through the cell partition wall. The exhaust gas that has been burned and purified is discharged from the exhaust gas outlet.

In the conventional oxidation catalyst device for exhaust gas purification, the catalyst is represented by the general formula AMO ₃ , and the A site has one or more of La, Y, Dy, Nd, etc., and 1 of Sr, Ba, Mg, etc. It is said that perovskite type composite metal oxides containing at least one kind of metal and at least one kind of metal such as Mn, Fe, Co and the like at the M site are used. Specific examples of the perovskite-type composite metal oxide include La _1-x Sr _x FeO ₃ (0.1 ≦ x ≦ 0.65) and La _1-x Ba _x FeO ₃ (0.1 ≦ x ≦ 0). .65) and the like.

Further, the present inventors, as the catalyst, represented by general formula _{Y 1-x Ag x Mn 1} -y A y O 3, A is one selected Ti, Nb, Ta, from the group consisting of Ru A perovskite-type composite metal oxide satisfying 0.01 ≦ x ≦ 0.15 and 0.005 ≦ y ≦ 0.2 has been proposed (see Patent Document 2).

  According to the oxidation catalyst device for exhaust gas purification provided with the perovskite-type composite metal oxide, the combustion temperature of the particulates can be lowered, but the combustion temperature can be further lowered, and combustion is performed in a short time. An oxidation catalyst device for exhaust gas purification that can be used is desired.

Japanese Patent Laid-Open No. 2007-237012 JP 2008-1000018 A

  An object of the present invention is to provide an oxidation catalyst device for purifying exhaust gas that can oxidize and burn particulates in exhaust gas of an internal combustion engine at a lower temperature and in a shorter time.

In order to achieve this object, the present invention provides a porous filter base material having a wall flow structure in which one end portion is an exhaust gas inflow portion and the other end portion is an exhaust gas inflow portion, and the porous filter base material The porous filter base material includes a plurality of through holes formed so as to penetrate in the axial direction, and the exhaust gas inflow portion is opened and the exhaust gas outflow portion is closed. An inflow cell, a plurality of outflow cells in which the exhaust gas inflow portions of the plurality of through holes are closed and the exhaust gas outflow portions are opened, and a cell partition wall that separates the inflow cells and the outflow cells, A first catalyst layer supported on at least a surface of the cell partition wall on the inflow cell side, and a second catalyst layer supported on a pore wall surface of the porous filter substrate forming the cell partition wall. Flow from the exhaust gas inlet For exhaust gas purification by oxidizing the particulates in the exhaust gas by the catalyst and flowing the purified exhaust gas out of the exhaust gas outflow part while circulating the exhaust gas of the internal combustion engine through the cell partition wall to the outflow cell in the oxidation catalyst device, the catalyst is represented by the general formula _{Y 1-x Ag x Mn 1} -y Ti y O 3, is 0.01 ≦ x ≦ 0.30 and 0.005 ≦ y ≦ 0.30 It consists of the porous body of the mixture of a composite metal oxide and a zirconium oxide.

The oxidation catalyst device for purifying exhaust gas according to the present invention comprises a first catalyst layer carried on at least the surface of the cell partition wall of the porous filter substrate having the wall flow structure, and the porous filter substrate. the catalyst to form the second catalyst layer supported on the wall surface forming the pores, is represented by the general formula _{Y 1-x Ag x Mn 1} -y Ti y O 3, 0.01 ≦ x ≦ 0. Combusting particulates in the exhaust gas of an internal combustion engine at a lower temperature and in a shorter time by using a porous body of a mixture of a complex metal oxide of 30 and 0.005 ≦ y ≦ 0.30 and zirconium oxide Can be made.

In the general formula _{Y 1-x Ag x Mn 1} -y A y O 3 of the complex metal oxide, the x is less than 0.01, the effect of enhancing the catalytic activity is insufficient, x is greater than 0.30 And the heat resistance of an oxidation catalyst falls and sufficient performance cannot be obtained. On the other hand, if y is less than 0.005, the effect of increasing the catalyst activity is insufficient, and if y exceeds 0.30, the heat resistance of the oxidation catalyst is lowered and sufficient performance cannot be obtained.

  In the oxidation catalyst device for exhaust gas purification according to the present invention, each of the catalyst layers is made of a porous body having pores having a diameter in a range of 0.01 to 3.0 μm, and the porous filter substrate and the entire catalyst layers The porosity is preferably in the range of 30 to 55% by volume. In the oxidation catalyst device for exhaust gas purification of the present invention, the pore diameter of the porous body forming each catalyst layer is within the above range, or the porous filter base material and the entire catalyst layer When the porosity is within the above range, the combustion temperature of the particulates in the exhaust gas of the internal combustion engine can be sufficiently lowered.

  In the oxidation catalyst device for exhaust gas purification of the present invention, pressure loss may increase when the pore diameter of the porous body forming each catalyst layer is less than 0.01 μm. On the other hand, when the pore diameter of each catalyst layer exceeds 3.0 μm, the particulates in the exhaust gas cannot sufficiently contact the surface of the pores, and the combustion temperature of the particulates is reduced. The effect of lowering may not be obtained sufficiently.

  Further, in the oxidation catalyst device for exhaust gas purification according to the present invention, when the porosity of the porous filter base material and each of the catalyst layers is less than 30% by volume, the pressure when the exhaust gas passes through the pores. Loss may increase. On the other hand, when the porosity of the entire porous filter substrate and each catalyst layer exceeds 55% by volume, the contact probability between the exhaust gas and the catalyst layer is lowered, and the combustion temperature of the particulates is lowered. The effect may not be obtained sufficiently.

It is explanatory drawing of the oxidation catalyst apparatus for exhaust gas purification of this invention, Fig.1 (a) is explanatory sectional drawing, FIG.1 (b) is a typical enlarged view of the A section of Fig.1 (a). ₂ is a graph showing the CO ₂ concentration of exhaust gas by the exhaust gas purification oxidation catalyst device of Example 1. FIG. 3 is a graph showing the pore diameters of the porous filter base material and each catalyst layer in the oxidation catalyst device for exhaust gas purification of Example 1. FIG. 3 is a graph showing the porosity of the porous filter base material and the entire catalyst layers in the oxidation catalyst device for exhaust gas purification of Example 1. FIG. FIG. 5A is a cross-sectional image of a cell partition wall of the oxidation catalyst device for exhaust gas purification of Example 1, FIG. 5A is a cross-sectional image at a magnification of 50 times, and FIG. 5B is an enlarged view of part A in FIG. A cross-sectional image with a magnification of 500 times shown. Explanatory drawing which shows the catalyst evaluation apparatus used for a catalyst performance evaluation test. The graph which shows the particulate combustion time by the oxidation catalyst apparatus for exhaust gas purification of Example 2-6. The graph which shows the diameter of the pore of the porous filter base material and each catalyst layer in the oxidation catalyst apparatus for exhaust gas purification of Example 2. FIG. The graph which shows the porosity of the porous filter base material in the oxidation catalyst apparatus for exhaust gas purification of Example 2-6 and each catalyst layer whole. 6 is a graph showing the pore diameters of the porous filter base material and each catalyst layer in the oxidation catalyst device for exhaust gas purification of Example 3. FIG. 6 is a graph showing the pore diameters of the porous filter base material and each catalyst layer in the oxidation catalyst device for exhaust gas purification of Example 4. FIG. 7 is a graph showing the pore diameters of the porous filter base material and each catalyst layer in the oxidation catalyst device for exhaust gas purification of Example 5. FIG. 7 is a graph showing pore diameters of a porous filter base material and each catalyst layer in an exhaust gas purification oxidation catalyst device of Example 6. FIG. The graph which shows the particulate combustion time by the oxidation catalyst apparatus for exhaust gas purification of Example 7-10. 10 is a graph showing the pore diameters of the porous filter base material and each catalyst layer in the oxidation catalyst device for exhaust gas purification of Example 7. FIG. The graph which shows the porosity of the porous filter base material in the oxidation catalyst apparatus for exhaust gas purification of Example 7-10 and each catalyst layer whole. 9 is a graph showing pore diameters of a porous filter base material and each catalyst layer in an oxidation catalyst device for exhaust gas purification of Example 8. FIG. The graph which shows the diameter of the pore of the porous filter base material and each catalyst layer in the oxidation catalyst apparatus for exhaust gas purification of Example 9. FIG. The graph which shows the diameter of the pore of the porous filter base material and each catalyst layer in the oxidation catalyst apparatus for exhaust gas purification of Example 10. FIG.

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. As shown in FIG. 1 (a), the exhaust gas purifying oxidation catalyst device 1 of this embodiment has a wall flow structure in which one end is an exhaust gas inflow portion 1a and the other end is an exhaust gas outflow portion 1b. A porous filter substrate 2 and a catalyst supported on the porous filter substrate 2 are provided.

  The porous filter substrate 2 is a porous body made of, for example, SiC, and includes a plurality of pores having a diameter in a range of 20 to 25 μm and a porosity in a range of 55 to 60% by volume. . The porous filter substrate 2 has, for example, a rectangular parallelepiped shape, and a plurality of through-holes penetrating in the axial direction are arranged in a cross-sectional lattice shape. It has. In the inflow cell 4, the end 4a on the exhaust gas inflow portion 1a side is opened, and the end 4b on the exhaust gas outflow portion 1b side is closed. On the other hand, in the outflow cell 5, the end portion 5a on the exhaust gas inflow portion 1a side is closed and the end portion 5b on the exhaust gas outflow portion 1b side is opened. The inflow cells 4 and the outflow cells 5 are alternately arranged so as to have a checkered cross section, and are separated from each other by cell partition walls 6 that form boundaries between the cells 4 and 5.

As shown in FIG. 1A, the exhaust gas purifying oxidation catalyst device 1 includes a first catalyst layer 3a supported on the surface of the cell partition wall 6 on the inflow cell 4 side, and a catalyst shown in FIG. As shown, a second catalyst layer 3b carried on the wall surface of the pore 7 of the cell partition wall 6 is provided. Each catalyst layer 3a, 3b is a porous body having pores (not shown) having a diameter in the range of 0.01 to 3.0 μm, and has a general formula Y _1-x Ag _x Mn _1-y Ti _y O ₃ and composed of a mixture of a composite metal oxide of 0.01 ≦ x ≦ 0.30 and 0.005 ≦ y ≦ 0.30 and zirconium oxide. The porous filter base material 2 and the catalyst layers 3a and 3b have a total porosity in the range of 30 to 55% by volume. Although not shown, a regulating member made of metal that regulates the outflow of exhaust gas is provided on the outer peripheral portion of the outermost cell partition wall 6.

  In the oxidation catalyst device 1 for exhaust gas purification, the first catalyst layer 3a is supported only on the surface on the inflow cell 4 side of the cell partition wall 6, but the surface on the inflow cell 4 side and the surface on the outflow cell 5 side It may be carried on both. Moreover, although the porous body which consists of SiC is used as the porous filter base material 2, you may use the porous body which consists of Si-SiC.

  Next, the operation of the exhaust gas purifying oxidation catalyst device 1 of the present embodiment will be described with reference to FIG. First, the exhaust gas purifying oxidation catalyst device 1 is installed so that the exhaust gas inflow portion 1a is upstream of the exhaust gas flow path of the internal combustion engine. In this way, since the end portion 5a of the outflow cell 5 is closed, the exhaust gas is introduced into the inflow cell 4 from the end portion 4a as indicated by an arrow in FIG.

  At this time, since the end portion of the inflow cell 4 on the exhaust gas outflow portion 1 b side is closed, the exhaust gas introduced into the inflow cell 4 is circulated into the outflow cell 5 through the pores 7 of the cell partition wall 6. It is done. During the circulation, the particulates in the exhaust gas are supported by the first catalyst layer 3 a supported on the surface of the cell partition wall 6 and the second catalyst layer 3 b supported on the wall surface of the pore 7. And is oxidized, burned and removed by the action of the catalyst of each catalyst layer 3a, 3b.

  As a result, the exhaust gas from which the particulates have been burned and removed is discharged to the outside from the end portion 5b of the outflow cell 5 on the exhaust gas outflow portion 1b side.

According to the exhaust gas purifying oxidation catalyst device 1 of the present embodiment, the catalyst to form a first catalyst layer 3a and the second catalyst layer 3b has the general formula _{Y 1-x Ag x Mn 1} -y Ti y O 3 In the exhaust gas of the internal combustion engine, the particulates in the exhaust gas of the internal combustion engine are formed by a mixture of a composite metal oxide expressed by the following formula: 0.01 ≦ x ≦ 0.30 and 0.005 ≦ y ≦ 0.30. It can be oxidized, burned and purified at a lower temperature and in a shorter time.

  Moreover, according to the oxidation catalyst device 1 for exhaust gas purification of the present embodiment, the first catalyst layer 3a and the second catalyst layer 3b are made of a porous body, and pores having a diameter in the range of 0.01 to 3.0 μm. 7 and the whole of the porous filter substrate 2 and the catalyst layers 3a and 3b has a porosity in the range of 30 to 55% by volume. As a result, the contact probability between the particulates in the exhaust gas and the catalyst layers 3a and 3b can be increased. Therefore, according to the present invention, it is possible to oxidize, burn and purify the particulates in the exhaust gas of the internal combustion engine at a lower temperature as compared with the oxidation catalyst device for exhaust gas purification of the prior art.

  Next, examples and comparative examples of the present invention are shown.

  In this example, first, yttrium nitrate pentahydrate, silver nitrate, manganese nitrate hexahydrate, anatase-type titanium oxide, citric acid, and water were added at 0.95: 0.05: 0. The mixture mixed at a molar ratio of 95: 0.05: 6: 40 was mixed and ground in a mortar at a temperature of 25 ° C. for 15 minutes, and then held at a temperature of 400 ° C. for 1 hour for primary firing. Next, a water-dispersed zirconia sol obtained by dispersing zirconium oxide powder in water (the content of zirconium oxide powder is 20% by mass), the content of zirconium oxide powder with respect to the resultant product obtained by the primary firing is as follows. The mixture was mixed so as to be 10% by mass, mixed and pulverized in a mortar for 15 minutes, and then mixed and pulverized at 100 rpm for 5 hours using a rotary ball mill to prepare a catalyst precursor slurry.

Next, a porous filter base material 2 (SiC porous body manufactured by Nippon Choshi Co., Ltd., trade name: MSC14) in which a plurality of through-holes penetrating in the axial direction was arranged in a lattice shape was prepared. The porous filter substrate 2 has a rectangular parallelepiped shape with an apparent volume of 65000 mm ³ having dimensions of 36 × 36 × 50 mm, and an average pore diameter is in the range of 20 to 25 μm.

  Next, every other end of the through hole of the porous filter base material 2 (that is, so as to have a cross-sectional checkered cross section), and clogged with a ceramic adhesive mainly composed of silica, An outflow cell 5 was formed. Next, by pouring the slurry into the porous filter substrate 2 from the side where the end is closed, the plurality of through holes whose ends are not closed (that is, cells other than the outflow cell 5). The slurry was allowed to flow into the inside, and then the excess slurry was removed from the porous filter substrate 2.

Next, the porous filter base material 2 to which the slurry was adhered was held at a temperature of 800 ° C. for 1 hour for secondary firing. As a result, on the surface of the cell partition wall 6 of the cells other than the outflow cell 5, the composite metal oxide represented by the chemical formula Y _0.95 Ag _0.05 Mn _0.95 Ti _0.05 O ₃ and zirconium oxide A first catalyst layer 3 a made of a porous mixture was formed, and a second catalyst layer 3 b made of the porous mixture was formed on the wall surfaces of the pores 7 of the cell partition walls 6. The catalyst layers 3a and 3b are porous bodies having pores having a diameter in the range of 0.01 to 3.0 μm by the secondary firing. The catalyst layers 3a and 3b have a total loading amount of 80 g per 1 L of apparent volume of the porous filter substrate 2.

  Next, by closing the end of the cell other than the outflow cell 5 on the side opposite to the side where the end is closed with a ceramic adhesive mainly composed of silica, the inflow cell 4 is formed. An exhaust gas purification oxidation catalyst device 1 having the configuration shown in FIG. The exhaust gas purifying oxidation catalyst device 1 has a porosity in the range of 30 to 55% by volume as a whole, including the porous filter substrate 2 and the catalyst layers 3a and 3b.

  Next, a catalyst performance evaluation test was performed on the oxidation catalyst device 1 for exhaust gas purification of this example as follows. First, the exhaust gas purification oxidation catalyst device 1 was mounted on an exhaust system of a diesel engine having a displacement of 2.4 L installed in an engine bench. Next, by operating the diesel engine for 20 minutes, the exhaust gas purification oxidation catalyst device 1 was allowed to collect 2 g of particulate per 1 L apparent volume of the exhaust gas purification oxidation catalyst device 1. The operating conditions of the diesel engine were an inflow gas temperature of 180 ° C. to the exhaust gas purification oxidation catalyst device 1, an engine speed of 1500 rpm, and a torque of 70 N / m.

Next, the exhaust gas-purifying oxidation catalyst device 1 in which the particulates were collected was taken out from the exhaust system and fixed in a quartz tube in a flow-type temperature rising device. Next, an atmospheric gas formed by mixing oxygen and nitrogen is supplied from one end portion (supply port) of the quartz tube and discharged from the other end portion (discharge port) of the quartz tube, and the exhaust gas purification oxidation catalyst. Apparatus 1 was heated. The atmospheric gas was supplied at a space velocity of 20000 / hour with a volume ratio of oxygen and nitrogen of 10:90. Further, the heating was performed by a tubular muffle furnace of the flow-type temperature raising device, and the exhaust gas purification oxidation catalyst device 1 was heated from room temperature to a temperature of 700 ° C. at a rate of 3 ° C./min. At this time, the CO ₂ concentration of the exhaust gas from the quartz tube was measured using a mass spectrometer. The results are shown in FIG. In FIG. 2, the temperature corresponding to the peak of the CO ₂ concentration corresponds to the combustion temperature of the particulates.

  Next, three 5 mm square cubes were cut out by cutting the oxidation catalyst device 1 for exhaust gas purification of this example with a diamond cutter.

  Next, for the first cubic exhaust gas purification oxidation catalyst device 1, using an automatic mercury porosimeter, the diameter of the pores of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a, 3b, The total porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b was measured. The measurement results of the diameter of the pores of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are shown in FIG. FIG. 4 shows the measurement results of the entire porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b.

  As shown in FIG. 3, in the oxidation catalyst device 1 for exhaust gas purification of the present embodiment, the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate 2 is in the range of 20 to 25 μm, the diameter of the pores of the catalyst layers 3a and 3b is considered to be in the range of 0.01 to 2.0 μm. It is done. Further, as shown in FIG. 4, in the exhaust gas purification oxidation catalyst device 1 of the present embodiment, the total porosity of the porous filter base material 2 and the catalyst layers 3a and 3b is 50.4% by volume. Is clear.

  Next, the cross-sectional image was image | photographed using the transmission electron microscope with respect to the oxidation catalyst apparatus 1 for exhaust gas purification of the 2nd cube. FIGS. 5A and 5B show cross-sectional images of the oxidation catalyst device 1 for exhaust gas purification. As shown in FIG. 5 (b), it is clear that the second catalyst layer 3b is formed on the wall surface of the pore 7 of the cell partition wall 6 in the exhaust gas purification oxidation catalyst device 1 of the present embodiment. .

Next, the components of the catalyst constituting the catalyst layers 3a and 3b were evaluated with respect to the third cubic oxidation catalyst device 1 for exhaust gas purification using an X-ray diffractometer. From the results of X-ray diffraction of the catalyst layers 3a and 3b, the catalyst was converted into zirconium oxide having a crystal peak due to YMO ₃ (M is a metal) which is a composite metal oxide and a main peak around 2θ = 31 °. Resulting crystal peaks.

Therefore, it is apparent that the catalyst is composed of a mixture of a complex metal oxide represented by the chemical formula Y _0.95 Ag _0.05 Mn _0.95 Ti _0.05 O ₃ and zirconium oxide. In addition, the said zirconium oxide is a cubic formed by dissolving a part of yttrium in Y _0.95 Ag _0.05 Mn _0.95 Ti _0.05 O ₃ , which is a composite metal oxide, in the zirconium oxide. Crystalline yttrium stabilized zirconia.
[Comparative Example 1]
In this comparative example, an exhaust gas purification oxidation catalyst device was manufactured in exactly the same manner as in Example 1 except that the catalyst layers 3a and 3b were not formed at all.

  Next, a catalyst performance evaluation test was performed on the oxidation catalyst device for exhaust gas purification of this comparative example in exactly the same manner as in Example 1. The results are shown in FIG.

  From FIG. 2, according to the oxidation catalyst device 1 for exhaust gas purification of Example 1, the particulates in the exhaust gas of the internal combustion engine are oxidized and burned at a lower temperature than the oxidation catalyst device for exhaust gas purification of this comparative example. Obviously it can be.

  Next, by cutting the oxidation catalyst device for exhaust gas purification of this comparative example with a diamond cutter, one 5 mm square cube was cut out.

  Next, the pore diameter of the porous filter substrate was measured with respect to the cubic oxidation catalyst device for exhaust gas purification using an automatic mercury porosimeter. The measurement results of the pore diameter of the porous filter substrate are shown in FIG.

As shown in FIG. 3, in the exhaust gas purifying oxidation catalyst device of this comparative example, it is apparent that the pores of the porous filter substrate have an average diameter in the range of 20 to 25 μm.
[Comparative Example 2]
In this comparative example, first, except that yttrium nitrate pentahydrate, manganese nitrate hexahydrate, citric acid, and water were mixed at a molar ratio of 1: 1: 6: 40, Example 1 A catalyst precursor slurry was prepared in exactly the same manner as in Example 1.

Next, using the catalyst precursor slurry obtained in this comparative example, a first catalyst layer and a second catalyst layer made of a porous mixture of a composite metal oxide represented by the chemical formula YMnO ₃ and zirconium oxide are used. Except that was formed, the oxidation catalyst device for exhaust gas purification of this comparative example was manufactured exactly the same as Example 1.

  Next, a catalyst performance evaluation test was performed on the oxidation catalyst device for exhaust gas purification of this comparative example in exactly the same manner as in Example 1. The results are shown in FIG.

  From FIG. 2, according to the oxidation catalyst device 1 for exhaust gas purification of Example 1, the particulates in the exhaust gas of the internal combustion engine are oxidized and burned at a lower temperature than the oxidation catalyst device for exhaust gas purification of this comparative example. Obviously it can be.

  Next, one 5 mm square cube was cut out from the oxidation catalyst device for exhaust gas purification of this comparative example exactly as in Example 1, and the pore diameter of the porous filter substrate and the first and second catalysts The pore diameter of the layer and the total porosity of the porous filter substrate and the first and second catalyst layers were measured. FIG. 3 shows the measurement results of the pore diameter of the porous filter substrate and the pore diameters of the first and second catalyst layers. FIG. 4 shows the measurement results of the entire porosity of the porous filter substrate and the first and second catalyst layers.

  As shown in FIG. 3, in the oxidation catalyst device for exhaust gas purification of this comparative example, the pore diameter of the porous filter substrate and the pore diameters of the first and second catalyst layers are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate is in the range of 20 to 25 μm, the diameter of the pores of the first and second catalyst layers is in the range of 0.20 to 5.0 μm. it is conceivable that. Further, as shown in FIG. 4, in the oxidation catalyst device for exhaust gas purification of this comparative example, the pore diameter of the porous filter substrate and the total porosity of the first and second catalyst layers are 61.1. It is clear that the volume is%.

  In this example, first, a catalyst precursor slurry was prepared in the same manner as in Example 1 except that the temperature of the primary firing was 350 ° C.

  Next, an oxidation catalyst device 1 for exhaust gas purification was manufactured in exactly the same manner as in Example 1 except that the catalyst precursor slurry obtained in this example was used.

  Next, a catalyst performance evaluation test was performed on the oxidation catalyst device 1 for exhaust gas purification of this example as follows. First, the exhaust gas purification oxidation catalyst device 1 was mounted on an exhaust system of a diesel engine having an exhaust amount of 2.2 L installed in an engine bench. Next, by operating the diesel engine, the exhaust gas purification oxidation catalyst device 1 was allowed to collect 1.4 g of particulate per liter apparent volume of the exhaust gas purification oxidation catalyst device 1. The operating conditions of the diesel engine were an inflow gas temperature of 300 ° C. to the exhaust gas purification oxidation catalyst device 1, an engine speed of 1500 rpm, and a torque of 80 N / m.

  Next, the exhaust gas-purifying oxidation catalyst device 1 in which a predetermined amount of particulates was collected was taken out of the exhaust system and fixed in the quartz tube 12 of the catalyst evaluation device 11 shown in FIG. Here, the catalyst evaluation apparatus 11 includes a heating furnace 13 around the quartz tube 12 and a plurality of gas cylinders 14, 15, and 16 on the one end 12 a side of the quartz tube 12. The gas cylinder 14 contains nitrogen monoxide, the gas cylinder 15 contains oxygen, and the gas cylinder 16 contains nitrogen.

  Next, the nitrogen gas supplied from the gas cylinder 16 is supplied from the one end portion 12a (supply port) of the quartz tube 12 at a flow rate of 12.8 L / min. The temperature was raised to 600 ° C.

  Next, nitrogen monoxide, oxygen, and nitrogen were supplied from the gas cylinders 14, 15, and 16 to generate a mixed gas having a volume ratio of 0.02: 3.8: 96.18. Next, the mixed gas was supplied from the one end portion 12a of the quartz tube 12 at a flow rate of 13.5 L / min. And the gas analyzer (the exhaust gas purifying oxidation catalyst device 1) connected to the other end portion 12b (exhaust port) of the quartz tube 12 with the carbon monoxide and carbon dioxide generated by the oxidation and combustion of the particulates. The product was introduced to HORIBA, Ltd., trade name: MEXA-7500D) 17. Next, the gas analyzer 17 measures the concentrations of carbon monoxide and carbon dioxide, and the time required until 90% by mass of the particulates collected in the exhaust gas purification oxidation catalyst device 1 are burned. Was measured. The results are shown in FIG.

  Next, one 5 mm square cube is cut out from the oxidation catalyst device 1 for exhaust gas purification of this example in exactly the same manner as in Example 1, and the pore diameter and catalyst layers 3a, 3b of the porous filter substrate 2 are cut out. The diameter of each of the pores 7 and the overall porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b were measured. FIG. 8 shows the measurement results of the pore diameter of the porous filter substrate 2 and the diameters of the pores 7 of the catalyst layers 3a and 3b. FIG. 9 shows the measurement results of the entire porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b.

  As shown in FIG. 8, in the exhaust gas purification oxidation catalyst device 1 of the present embodiment, the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate 2 is in the range of 20 to 25 μm, the diameter of the pores of the catalyst layers 3a and 3b is considered to be in the range of 0.01 to 2.0 μm. It is done. Moreover, as shown in FIG. 9, in the oxidation catalyst device 1 for exhaust gas purification of the present embodiment, the total porosity of the porous filter base material 2 and the catalyst layers 3a and 3b is 41.5% by volume. Is clear.

  In this example, first, yttrium nitrate pentahydrate, silver nitrate, manganese nitrate hexahydrate, anatase-type titanium oxide, citric acid, and water were 0.90: 0.10: 0. A catalyst precursor slurry was prepared in exactly the same manner as in Example 2 except that the mixture was mixed at a molar ratio of 95: 0.05: 6: 40.

Next, using the catalyst precursor slurry obtained in this example, a mixture of a composite metal oxide represented by the chemical formula Y _0.9 Ag _0.1 Mn _0.95 Ti _0.05 O ₃ and zirconium oxide. Exhaust gas purification oxidation catalyst device 1 was manufactured in exactly the same manner as in Example 2, except that the first catalyst layer 3a and the second catalyst layer 3b made of the porous material were formed.

  Next, exactly the same as Example 2 except that 1.9 g of particulates per 1 L of apparent volume of the exhaust gas purification oxidation catalyst device 1 was collected with respect to the exhaust gas purification oxidation catalyst device 1 of the present example. Thus, a catalyst performance evaluation test was conducted. The results are shown in FIG.

  Next, one 5 mm square cube is cut out from the oxidation catalyst device 1 for exhaust gas purification of this example in exactly the same manner as in Example 2, and the pore diameter of the porous filter substrate 2 and the catalyst layers 3a, 3b are cut out. The diameter of each of the pores 7 and the overall porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b were measured. FIG. 10 shows the measurement results of the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b. FIG. 9 shows the measurement results of the entire porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b.

  As shown in FIG. 10, in the oxidation catalyst device 1 for exhaust gas purification according to the present embodiment, the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate 2 is in the range of 20 to 25 μm, the diameter of the pores of the catalyst layers 3a and 3b is considered to be in the range of 0.02 to 2.0 μm. It is done. Further, as shown in FIG. 9, in the exhaust gas purification oxidation catalyst device 1 of the present embodiment, the total porosity of the porous filter base material 2 and the catalyst layers 3a and 3b is 41.0% by volume. Is clear.

  In this example, first, yttrium nitrate pentahydrate, silver nitrate, manganese nitrate hexahydrate, anatase-type titanium oxide, citric acid, and water were added at 0.85: 0.15: 0. A catalyst precursor slurry was prepared in exactly the same manner as in Example 2 except that the mixture was mixed at a molar ratio of 95: 0.05: 6: 40.

Next, using the catalyst precursor slurry obtained in this example, a mixture of a composite metal oxide represented by the chemical formula Y _0.85 Ag _0.15 Mn _0.95 Ti _0.05 O ₃ and zirconium oxide Exhaust gas purification oxidation catalyst device 1 was manufactured in exactly the same manner as in Example 2, except that the first catalyst layer 3a and the second catalyst layer 3b made of the porous material were formed.

  Next, exactly the same as Example 2 except that 1.8 g of particulate per 1 L apparent volume of the exhaust gas purification oxidation catalyst device 1 was collected with respect to the exhaust gas purification oxidation catalyst device 1 of this example. Thus, a catalyst performance evaluation test was conducted. The results are shown in FIG.

  Next, one 5 mm square cube is cut out from the oxidation catalyst device 1 for exhaust gas purification of this example in exactly the same manner as in Example 2, and the pore diameter of the porous filter substrate 2 and the catalyst layers 3a, 3b are cut out. The diameter of each of the pores 7 and the overall porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b were measured. FIG. 11 shows the measurement results of the pore diameter of the porous filter substrate 2 and the diameters of the pores 7 of the catalyst layers 3a and 3b. FIG. 9 shows the measurement results of the entire porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b.

  As shown in FIG. 11, in the oxidation catalyst device 1 for exhaust gas purification of the present embodiment, the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate 2 is in the range of 20 to 25 μm, the diameter of the pores of the catalyst layers 3a and 3b is considered to be in the range of 0.02 to 3.0 μm. It is done. Moreover, as shown in FIG. 9, in the exhaust gas purification oxidation catalyst device 1 of the present embodiment, the total porosity of the porous filter base material 2 and the catalyst layers 3a and 3b is 42.0% by volume. Is clear.

  In this example, first, yttrium nitrate pentahydrate, silver nitrate, manganese nitrate hexahydrate, anatase-type titanium oxide, citric acid, and water were added at 0.80: 0.20: 0. A catalyst precursor slurry was prepared in exactly the same manner as in Example 2 except that the mixture was mixed at a molar ratio of 95: 0.05: 6: 40.

Next, using the catalyst precursor slurry obtained in this example, a mixture of a composite metal oxide represented by the chemical formula Y _0.8 Ag _0.2 Mn _0.95 Ti _0.05 O ₃ and zirconium oxide. Exhaust gas purification oxidation catalyst device 1 was manufactured in exactly the same manner as in Example 2, except that the first catalyst layer 3a and the second catalyst layer 3b made of the porous material were formed.

  Next, exactly the same as Example 2 except that 1.8 g of particulate per 1 L apparent volume of the exhaust gas purification oxidation catalyst device 1 was collected with respect to the exhaust gas purification oxidation catalyst device 1 of this example. Thus, a catalyst performance evaluation test was conducted. The results are shown in FIG.

  Next, one 5 mm square cube is cut out from the oxidation catalyst device 1 for exhaust gas purification of this example in exactly the same manner as in Example 2, and the pore diameter of the porous filter substrate 2 and the catalyst layers 3a, 3b are cut out. The diameter of each of the pores 7 and the overall porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b were measured. The measurement results of the pore diameter of the porous filter substrate 2 and the diameters of the pores 7 of the catalyst layers 3a and 3b are shown in FIG. FIG. 9 shows the measurement results of the entire porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b.

  As shown in FIG. 12, in the exhaust gas purifying oxidation catalyst device 1 of the present embodiment, the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate 2 is in the range of 20 to 25 μm, the diameter of the pores of the catalyst layers 3a and 3b is considered to be in the range of 0.02 to 2.0 μm. It is done. Further, as shown in FIG. 9, in the exhaust gas purification oxidation catalyst device 1 of the present embodiment, the total porosity of the porous filter base material 2 and the catalyst layers 3a and 3b is 47.8% by volume. Is clear.

  In this example, first, yttrium nitrate pentahydrate, silver nitrate, manganese nitrate hexahydrate, anatase-type titanium oxide, citric acid, and water were 0.70: 0.30: 0. A catalyst precursor slurry was prepared in exactly the same manner as in Example 2 except that the mixture was mixed at a molar ratio of 95: 0.05: 6: 40.

Next, using the catalyst precursor slurry obtained in this example, a mixture of a composite metal oxide represented by the chemical formula Y _0.7 Ag _0.3 Mn _0.95 Ti _0.05 O ₃ and zirconium oxide. Exhaust gas purification oxidation catalyst device 1 was manufactured in exactly the same manner as in Example 2, except that the first catalyst layer 3a and the second catalyst layer 3b made of the porous material were formed.

  Next, the exhaust gas purification oxidation catalyst device 1 of the present embodiment is exactly the same as the embodiment 2 except that 1.7 g of particulate per 1 L apparent volume of the exhaust gas purification oxidation catalyst device 1 is collected. Thus, a catalyst performance evaluation test was conducted. The results are shown in FIG.

From FIG. 7, the porosity of the mixture of the composite metal oxide represented by the general formula Y _1-x Ag _x Mn _0.95 Ti _0.05 O ₃ (0.05 ≦ x ≦ 0.30) and zirconium oxide In the oxidation catalyst device 1 for exhaust gas purification of Examples 2 to 6 including the first catalyst layer 3a and the second catalyst layer 3b made of 90% by mass of 90% by mass of the collected particulates. It is clear that all the time required is less than 250 seconds. Therefore, it is clear that the oxidation catalyst device 1 for exhaust gas purification of Examples 2 to 6 can oxidize and burn the particulates in the exhaust gas of the internal combustion engine in a short time.

  Next, one 5 mm square cube is cut out from the oxidation catalyst device 1 for exhaust gas purification of this example in exactly the same manner as in Example 2, and the pore diameter of the porous filter substrate 2 and the catalyst layers 3a, 3b are cut out. The diameter of each of the pores 7 and the overall porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b were measured. The measurement results of the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are shown in FIG. FIG. 9 shows the measurement results of the entire porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b.

  As shown in FIG. 13, in the oxidation catalyst device 1 for exhaust gas purification of the present embodiment, the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate 2 is in the range of 20 to 25 μm, the diameter of the pores of the catalyst layers 3a and 3b is considered to be in the range of 0.02 to 2.0 μm. It is done. Further, as shown in FIG. 9, in the exhaust gas purification oxidation catalyst device 1 of the present embodiment, the total porosity of the porous filter base material 2 and the catalyst layers 3a and 3b is 41.3% by volume. Is clear.

From FIG. 7, among the oxidation catalyst devices 1 for exhaust gas purification of Examples 2 to 6, the composite metal oxide represented by the chemical formula Y _0.8 Ag _0.2 Mn _0.95 Ti _0.05 O ₃ and zirconium oxide It is clear that the time for the oxidation catalyst device 1 for exhaust gas purification of Example 5 provided with the first catalyst layer 3a and the second catalyst layer 3b made of a porous mixture of the above and the like is the shortest.

  Therefore, in this example, first, yttrium nitrate pentahydrate, silver nitrate, manganese nitrate hexahydrate, anatase-type titanium oxide, citric acid, and water were added at 0.80: 0.20: A catalyst precursor slurry was prepared in exactly the same manner as in Example 5 except that mixing was performed at a molar ratio of 0.90: 0.10: 6: 40.

Next, using the catalyst precursor slurry obtained in this example, a mixture of a composite metal oxide represented by the chemical formula Y _0.8 Ag _0.2 Mn _0.9 Ti _0.1 O ₃ and zirconium oxide Exhaust gas purification oxidation catalyst device 1 was manufactured in exactly the same manner as in Example 5, except that the first catalyst layer 3a and the second catalyst layer 3b made of the porous material were formed.

  Next, the exhaust gas purification oxidation catalyst device 1 of this example is exactly the same as Example 5 except that 1.4 g of particulates per 1 L apparent volume of the exhaust gas purification oxidation catalyst device 1 were collected. Thus, a catalyst performance evaluation test was conducted. The results are shown in FIG.

  Next, one 5 mm square cube was cut out from the oxidation catalyst device 1 for exhaust gas purification of this example exactly as in Example 5, and the pore diameter of the porous filter substrate 2 and the catalyst layers 3a, 3b were cut out. The diameter of each of the pores 7 and the overall porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b were measured. FIG. 15 shows the measurement results of the pore diameter of the porous filter substrate 2 and the diameters of the pores 7 of the catalyst layers 3a and 3b. FIG. 16 shows the measurement results of the entire porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b.

  As shown in FIG. 15, in the exhaust gas purifying oxidation catalyst device 1 of the present embodiment, the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate 2 is in the range of 20 to 25 μm, the diameter of the pores of the catalyst layers 3a and 3b is considered to be in the range of 0.02 to 2.0 μm. It is done. Moreover, as shown in FIG. 16, in the oxidation catalyst device 1 for exhaust gas purification of the present embodiment, the total porosity of the porous filter base material 2 and the catalyst layers 3a and 3b is 48.6% by volume. Is clear.

  In this example, first, yttrium nitrate pentahydrate, silver nitrate, manganese nitrate hexahydrate, anatase-type titanium oxide, citric acid, and water were added at 0.80: 0.20: 0. A catalyst precursor slurry was prepared in exactly the same manner as in Example 5 except that the mixing was performed at a molar ratio of 85: 0.15: 6: 40.

Next, using the catalyst precursor slurry obtained in this example, a mixture of a composite metal oxide represented by the chemical formula Y _0.8 Ag _0.2 Mn _0.85 Ti _0.15 O ₃ and zirconium oxide. Exhaust gas purification oxidation catalyst device 1 was manufactured in exactly the same manner as in Example 5, except that the first catalyst layer 3a and the second catalyst layer 3b made of the porous material were formed.

  Next, exactly the same as Example 5 except that 1.6 g of particulate per 1 L apparent volume of the exhaust gas purification oxidation catalyst device 1 was collected with respect to the exhaust gas purification oxidation catalyst device 1 of the present example. Thus, a catalyst performance evaluation test was conducted. The results are shown in FIG.

  Next, one 5 mm square cube was cut out from the oxidation catalyst device 1 for exhaust gas purification of this example exactly as in Example 5, and the pore diameter of the porous filter substrate 2 and the catalyst layers 3a, 3b were cut out. The diameter of each of the pores 7 and the overall porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b were measured. FIG. 17 shows the measurement results of the pore diameter of the porous filter substrate 2 and the diameters of the pores 7 of the catalyst layers 3a and 3b. FIG. 16 shows the measurement results of the entire porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b.

  As shown in FIG. 17, in the oxidation catalyst device 1 for exhaust gas purification according to the present embodiment, the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate 2 is in the range of 20 to 25 μm, the diameter of the pores of the catalyst layers 3a and 3b is considered to be in the range of 0.01 to 0.5 μm. It is done. Further, as shown in FIG. 16, in the exhaust gas purification oxidation catalyst device 1 of the present embodiment, the total porosity of the porous filter base material 2 and the catalyst layers 3a and 3b is 35.5% by volume. Is clear.

  In this example, first, yttrium nitrate pentahydrate, silver nitrate, manganese nitrate hexahydrate, anatase-type titanium oxide, citric acid, and water were added at 0.80: 0.20: 0. A catalyst precursor slurry was prepared in exactly the same manner as in Example 5 except that the mixing was performed at a molar ratio of 80: 0.20: 6: 40.

Next, using the catalyst precursor slurry obtained in this example, a mixture of a composite metal oxide represented by the chemical formula Y _0.8 Ag _0.2 Mn _0.8 Ti _0.2 O ₃ and zirconium oxide. Exhaust gas purification oxidation catalyst device 1 was manufactured in exactly the same manner as in Example 5, except that the first catalyst layer 3a and the second catalyst layer 3b made of the porous material were formed.

  Next, the exhaust gas purification oxidation catalyst device 1 of this example is exactly the same as Example 5 except that 1.4 g of particulates per 1 L apparent volume of the exhaust gas purification oxidation catalyst device 1 were collected. Thus, a catalyst performance evaluation test was conducted. The results are shown in FIG.

  Next, one 5 mm square cube was cut out from the oxidation catalyst device 1 for exhaust gas purification of this example exactly as in Example 5, and the pore diameter of the porous filter substrate 2 and the catalyst layers 3a, 3b were cut out. The diameter of each of the pores 7 and the overall porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b were measured. FIG. 18 shows the measurement results of the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b. FIG. 16 shows the measurement results of the entire porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b.

  As shown in FIG. 18, in the oxidation catalyst device 1 for exhaust gas purification of this example, the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate 2 is in the range of 20 to 25 μm, the diameter of the pores of the catalyst layers 3a and 3b is considered to be in the range of 0.20 to 1.0 μm. It is done. Further, as shown in FIG. 16, in the exhaust gas purification oxidation catalyst device 1 of the present embodiment, the total porosity of the porous filter base material 2 and the catalyst layers 3a and 3b is 41.2% by volume. Is clear.

  In this example, first, yttrium nitrate pentahydrate, silver nitrate, manganese nitrate hexahydrate, anatase-type titanium oxide, citric acid, and water were added at 0.80: 0.20: 0. A catalyst precursor slurry was prepared in exactly the same manner as in Example 5 except that mixing was performed at a molar ratio of 70: 0.30: 6: 40.

Next, using the catalyst precursor slurry obtained in this example, a mixture of a composite metal oxide represented by the chemical formula Y _0.8 Ag _0.2 Mn _0.7 Ti _0.3 O ₃ and zirconium oxide. Exhaust gas purification oxidation catalyst device 1 was manufactured in exactly the same manner as in Example 5, except that the first catalyst layer 3a and the second catalyst layer 3b made of the porous material were formed.

  Next, exactly the same as Example 5 except that 1.5 g of particulate per 1 L apparent volume of the exhaust gas purification oxidation catalyst device 1 was collected with respect to the exhaust gas purification oxidation catalyst device 1 of the present example. Thus, a catalyst performance evaluation test was conducted. The results are shown in FIG.

  Next, one 5 mm square cube was cut out from the oxidation catalyst device 1 for exhaust gas purification of this example exactly as in Example 5, and the pore diameter of the porous filter substrate 2 and the catalyst layers 3a, 3b were cut out. The diameter of each of the pores 7 and the overall porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b were measured. FIG. 19 shows the measurement results of the pore diameter of the porous filter substrate 2 and the diameters of the pores 7 of the catalyst layers 3a and 3b. FIG. 16 shows the measurement results of the entire porosity of the porous filter substrate 2 and the catalyst layers 3a and 3b.

  As shown in FIG. 19, in the exhaust gas purification oxidation catalyst device 1 of the present embodiment, the pore diameter of the porous filter substrate 2 and the diameter of the pores 7 of the catalyst layers 3a and 3b are in the range of 0.01 to 100 μm. It was in. Here, considering that the average diameter of the pores of the porous filter substrate 2 is in the range of 20 to 25 μm, the diameter of the pores of the catalyst layers 3a and 3b is considered to be in the range of 0.02 to 2.0 μm. It is done. Moreover, as shown in FIG. 16, in the exhaust gas purification oxidation catalyst device 1 of the present embodiment, the total porosity of the porous filter base material 2 and the catalyst layers 3a and 3b is 43.3% by volume. Is clear.

From FIG. 14, the porosity of the mixture of the composite metal oxide represented by the general formula Y _0.8 Ag _0.2 Mn _1-y Ti _y O ₃ (0.05 ≦ y ≦ 0.30) and zirconium oxide. In the oxidation catalyst device 1 for exhaust gas purification of Examples 5 and 7 to 10 including the first catalyst layer 3a and the second catalyst layer 3b made of 90% of the collected particulates are burned. It is clear that all of the time required until is less than 130 seconds. Therefore, the oxidation catalyst device 1 for exhaust gas purification of Examples 5 and 7 to 10 has a shorter particulate matter in the exhaust gas of the internal combustion engine than the oxidation catalyst device 1 for exhaust gas purification of Examples 2 to 4 and 6. It is clear that it can oxidize and burn in time.

  DESCRIPTION OF SYMBOLS 1 ... Oxidation catalyst apparatus for exhaust gas purification, 2 ... Porous filter base material, 3a ... 1st catalyst layer, 3b ... 2nd catalyst layer, 4 ... Inflow cell, 5 ... Outflow cell, 6 ... Cell partition, 7 ... Pores.

Claims (2)

A porous filter base material having a wall flow structure in which one end portion is an exhaust gas inflow portion and the other end portion is an exhaust gas outflow portion, and a catalyst supported on the porous filter base material,
The porous filter base material includes: a plurality of inflow cells in which an exhaust gas inflow portion is opened and an exhaust gas outflow portion is blocked, and the plurality of through holes among the plurality of through holes formed to penetrate in the axial direction A plurality of outflow cells in which the exhaust gas inflow portion is closed and the exhaust gas outflow portion is opened, and the inflow cell and a cell partition partitioning the outflow cell,
The catalyst includes a first catalyst layer supported on at least the surface of the cell partition wall on the inflow cell side, and a second catalyst layer supported on the pore wall surface of the porous filter base material forming the cell partition wall. Consisting of a catalyst layer,
While the exhaust gas of the internal combustion engine flowing in from the exhaust gas inflow part is circulated to the outflow cell through the cell partition wall, the particulates in the exhaust gas are oxidized by the catalyst, and the purified exhaust gas is converted into the exhaust gas outflow part. In the oxidation catalyst device for exhaust gas purification that flows out from
The catalyst is represented by the general formula _{Y 1-x Ag x Mn 1} -y Ti y O 3, and complex metal oxides is 0.01 ≦ x ≦ 0.30 and 0.005 ≦ y ≦ 0.30 An oxidation catalyst device for exhaust gas purification comprising a porous body of a mixture with zirconium oxide.   Each of the catalyst layers is made of a porous body having pores having a diameter in the range of 0.01 to 3.0 μm, and the porosity of the porous filter substrate and the entire catalyst layers is 30 to 55% by volume. The oxidation catalyst device for exhaust gas purification according to claim 1, wherein the oxidation catalyst device is in a range.