JP4900663B2 - Exhaust gas purification filter and manufacturing method thereof - Google Patents

Description

  The present invention relates to an exhaust gas purification filter in which a filter base material for an exhaust gas purification filter is composed of a new material system, and more specifically, manufactured using a specific ternary compound ceramic material as a filter base material. The present invention relates to an exhaust gas purifying filter having advantages such as high thermal conductivity, vibration damping properties, and thermal shock resistance, and a method for manufacturing the same. The present invention uses a ternary compound, which is a new material system, as a filter substrate, and thus has low thermal conductivity and low thermal shock resistance, which are disadvantages of conventional cordierite and silicon carbide exhaust gas purification filters. A new exhaust gas purification system that improves low-vibration performance and improves wettability, especially for metal savings, and enables higher performance and lower cost of exhaust gas purification filters. It provides new technologies and new products related to filter members.

Exhaust gas purification filters such as diesel engines and gasoline engines capture PM in order to reduce particulate matter (PM), hydrocarbons (HC), and nitrogen suboxide (NO _x ) contained in the exhaust gas. It is used to oxidize PM, HC, and NO _x to CO ₂ , H ₂ O, and NO ₂ with a catalyst that is collected or supported on a filter. Since this exhaust gas purifying filter is exposed to high temperature exhaust gas for a long time, a high melting point, stability that does not decompose at high temperature, high temperature strength, and high temperature oxidation resistance are required.

  Further, in order to realize a thermal shock resistance against a thermal shock caused by abnormal combustion of the engine, a high specific surface area for efficiently collecting PM, and a low pressure loss, a narrow pore size distribution is required. Further, immediately after the engine is started, the temperature of the catalyst is low and the catalyst is not activated. Therefore, in order to activate the catalyst in a short time, the filter is required to have high thermal conductivity. Furthermore, good catalyst wettability for reducing the amount of catalyst supported is required. Moreover, in order to reduce the exhaust sound which is a noise, damping property is calculated | required.

  Cordierite, silicon carbide, or the like is used as a material that satisfies these conditions to some extent. As an exhaust gas purification filter using an intermetallic compound, tungsten carbide, molybdenum carbide, silicon carbide, tungsten silicide, molybdenum silicide, and tantalum silicide are chemically vaporized as the catalyst stationary phase between the filter substrate and the catalyst. The thing formed by the phase evaporation method (CVD) is proposed (patent document 1). This is for heating by energizing the catalyst stationary phase in order to shorten the catalyst activation time immediately after the engine is started. In addition, various honeycomb structures, diesel particulate filter devices, diesel exhaust gas purification technologies, and the like have been proposed (Patent Documents 2 to 3, Non-Patent Documents 1 and 2).

  However, cordierite has good thermal shock resistance due to its low thermal expansion coefficient, but its thermal conductivity is low, so the initial activation time of the catalyst is insufficiently shortened. Also, silicon carbide DPF, which has higher strength and higher thermal conductivity than cordierite, is being applied mainly for small passenger cars, but its thermal shock resistance is insufficient. In order to relieve the thermal stress, a structure of extruding to about 3 cm square and bonding after sintering is adopted. However, this structure increases the manufacturing cost, and it is particularly difficult to apply to a large size. In addition, none of the materials has sufficient vibration damping properties, and the effect of reducing exhaust noise is insufficient. Furthermore, in general, a platinum catalyst is supported on DPF using γ-alumina as a carrier for regeneration, and reduction of the amount of catalyst used is essential for cost reduction. For this purpose, a material having a surface with high wettability to γ-alumina is required. In general, non-oxides have poor polarity and poor wettability, so that a high concentration of slurry is used to carry the catalyst excessively.

Japanese Patent Laid-Open No. 06-055034 JP 2004-298709 A JP 2004-263593 A Shinichi Miwa, “Honeycomb Ceramics for Diesel Exhaust Gas Purification”, Industrial Materials, Monthly Industrial Newspaper, vol. 50, no. 13, pp. 22-26, December 2002 Supervision by Narusaki Sugawara, “Diesel vehicle exhaust gas particulate removal technology”, CMMC, pp. 204-222, 2001

Under such circumstances, the present inventors have found that the low heat conductivity, low thermal shock resistance, low vibration damping, and metal saving, which are the disadvantages of conventional exhaust gas purification filters made of cordierite or silicon carbide. Results of intensive research with the goal of developing new exhaust gas purification filter members that can improve the wettability and improve the performance and cost of exhaust gas purification filters , one of the specific transition metal element, used one of the 3 B or group 4 B group element, and specific ternary compound ceramic material consisting of three elements of carbon or nitrogen as the filter substrate It has been found that the intended purpose can be achieved by using the filter member, and further research has been made to complete the present invention. It is an object of the present invention to provide a new exhaust gas purifying filter that uses the above-mentioned specific ternary compound as a filter base material, and which can improve the performance and cost of the filter, and a method for producing the same. To do.

The present invention for solving the above-described problems comprises the following technical means.
(1) In the exhaust gas purifying filter, the filter substrate is, Ti transition metal element, Nb, Cr, Ta, V, one of M o, 3 B or Group 4 B group element Al, Si, one, and ternary ternary compounds made filter substrate der Rukoto of pores with a controlled configured size or shape having therein a compound consisting of three elements of carbon or nitrogen in the S n , And the wettability based on the fine structure of the atomic surface generated on the surface of the ternary compound, the surface is coated with any of γ-alumina, ceria, zirconia or a composite oxide thereof. And an exhaust gas purifying filter , wherein a catalyst component is supported .
(2) one of the transition metal elements: one 3 B or Group 4 B group element: element ratio of a ternary compound consisting of three elements carbon or nitrogen, in this order 3: 1: 2 or 2: The exhaust gas purifying filter according to the above (1), which is 1: 1 or 4: 1: 3.
(3) a transition metal element, 3 a B group or a 4 B group element, a mixture of flour powder or whiskers or fibers ternary compound material consisting of three elements of carbon or nitrogen, heated to the reaction A method for producing a ternary compound for a filter, comprising producing a ternary compound having pores whose sizes and shapes are controlled therein .
(4) a transition metal elements, 3 B or Group 4 one B group element, a mixture of powder or whiskers or fibers having a predetermined particle size distribution of the ternary compound material consisting of three elements of carbon or nitrogen Is manufactured into a filter shape and then heated to synthesize and sinter the ternary compound to produce a ternary compound filter base material having pores whose size and shape are controlled inside. A method for producing an exhaust gas purifying filter base material.
( 5 ) A powder having a predetermined particle size distribution obtained by pulverizing and classifying the ternary compound produced by the method described in ( 3 ) above was molded into a filter shape and then sintered to control the size. The method for producing a filter base material for exhaust gas purification according to (4), wherein a filter base material made of a ternary compound having pores is produced.
( 6 ) The exhaust gas purification filter substrate according to ( 4 ) or ( 5 ), wherein Al or Si is further added as a fourth element for lowering the sintering temperature to the composition of the ternary compound raw material. Production method.
( 7 ) The surface of the filter substrate according to any one of ( 4 ) to ( 6 ) is coated with any one of α-alumina, ceria, zirconia, or a composite oxide thereof and loaded with a catalyst component. A method for producing a filter for purifying exhaust gas, which is characterized.

Next, the present invention will be described in more detail.
The present invention, in the discharged gas purifying filter, the filter substrate is one of transition metal elements (Ti, Nb, Cr, Ta , V, Mo), 3 B or Group 4 B group element (Al, Si , Sn), and a specific ternary compound composed of three elements of carbon or nitrogen. In the present invention, the ternary compound, its element ratio, the transition metal element: 3 B or Group 4B group elements, carbon or nitrogen = 3: 1: 2 or 2: 1: 1 or 4: 1: 3 It is a preferred embodiment.

  When these ternary compounds are used as filter substrates, it is possible to give the filter a thermal conductivity more than twice that of metallic titanium, a thermal shock resistance with a temperature difference of 1400 ° C, and sufficient vibration damping properties. It is. Therefore, the present invention uses the above ternary compound as a filter base material, so that the thermal conductivity exceeding the conventional cordierite filter, the thermal shock resistance exceeding the silicon carbide filter, and the vibration damping exceeding both. It becomes possible to construct and provide a filter for purifying exhaust gas having the property.

Further, the present invention is a method for manufacturing a ternary compound for the filter, transition metal elements, 3 B or Group 4 B group element, carbon or nitrogen (carbide or nitride of a transition metal, 3 B or Group 4 The ternary compound is produced by heating and reacting a powder or a mixture of whiskers or fibers having a narrow particle size distribution of a group B element carbide or nitride). The synthesis reaction of the ternary compound proceeds by diffusing the group 3 B or group 4 B element, carbon, or nitrogen into the transition metal particles. Therefore, 3 B or Group 4 B group element, a mixture of particles or whiskers or fibers of raw material containing carbon or nitrogen, 3 B or Group 4 B group element, by a carbon or nitrogen diffuses into the transition metal particles, A ternary compound and member having pores whose sizes and shapes are controlled can be manufactured by utilizing the formation of cavities and the change in the shape of transition metal particles due to diffusion.

  In the present invention, the exhaust gas purifying filter can be produced by forming the above-mentioned powder, whisker, or fiber mixture into a filter shape and then heating to synthesize and sinter the ternary compound. it can. This makes it possible to manufacture and provide a filter made of a ternary compound having pores whose size and shape are controlled inside.

  In the present invention, the exhaust gas purifying filter is manufactured by forming a powder having a narrow particle size distribution obtained by pulverizing and classifying the ternary compound produced by the above-described method into a filter shape, and then sintering the powder. can do. By sintering a powder having a narrow particle size distribution, a ternary compound filter having pores with controlled sizes inside can be produced and provided. In general, a surface with irregularities on the surface is more easily wet than a smooth surface. The ceramic material obtained in the present invention has micron to nano level fine steps, and the surface is uniformly coated with slurry of γ alumina, ceria, zirconia, etc., and as a result, the amount of catalyst is also reduced. can do.

In the method of manufacturing the exhaust gas purifying ternary compounds of the present invention, first, a transition metal element used as the starting material, 3 B or Group 4 B group element, carbon or nitrogen (carbon, carbides of transition metals, nitride of a transition metal objects, 3 carbides B or group 4 B group element, 3 a B group or a 4 narrow powder or whiskers or fibers particle size distribution of the ternary compound consisting of three elements of nitrides of B group element), object 3 Mix in a combination and mixing ratio suitable for the synthesis of the original compound.

  Mixing may be dry or wet, and may be mechanical mixing or manual mixing. Usually, dry (in air or inert gas) mixing using a V-type mixer or turbula mixer or wet (in an organic solvent such as ethanol or hexane) mixing using a rotary ball mill is performed for about 1 to 50 hours. The particle diameter of the powder, the diameter of the whisker, or the fiber is set so as to obtain the target pore diameter. Further, in order to perform extrusion molding into a filter shape, a shape-retaining material may be mixed and kneaded.

  This mixture is put in a container made of graphite, alumina, or the like, and heated in vacuum or in an inert gas atmosphere under conditions (temperature, time) necessary for synthesis, thereby synthesizing a target ternary compound powder. This synthetic powder is pulverized using a pulverizer such as a ball mill, and classified using a classifier such as a sieve or an airflow classifier, and divided into powders having a narrow particle size distribution. In order to obtain a desired pore size distribution, a raw material having an appropriate particle size is formed into a filter shape by a powder press device or an extrusion device, and solidified by a sintering device. Sintering is performed in a vacuum or an inert gas, and the sintering temperature is mainly in the range of 1400 ° C to 1700 ° C. The sintering temperature holding time is mainly 30 minutes to 4 hours.

  If the sintering temperature is less than 1400 ° C., the sintering is not sufficient, and if the sintering temperature exceeds 1700 ° C., decomposition of the ternary compound may occur. If the sintering time is less than 30 minutes, sintering is not sufficient, and if it exceeds 4 hours, energy may be wasted. However, these conditions are not fixed, and suitable conditions are appropriately selected depending on the type of the target ternary compound. A small amount of a fourth element (Al, Si, etc.) that lowers the sintering temperature can be added to the composition of the ternary compound raw material.

  Without synthesizing the ternary compound powder, the raw material mixture is molded into a filter shape by a powder press or extrusion molding device, and then heated in a vacuum or an inert gas to synthesize and sinter solidify the ternary compound. It is also possible to produce a ternary compound filter. In the case of extrusion molding, an appropriate shape-retaining material is required. The heating conditions (temperature, time) can be the same as or lower than the above sintering conditions and in a short time, but these conditions are not fixed, and are the types of target ternary compounds. The suitable conditions are appropriately selected according to the above.

The present invention provides a filter for purifying exhaust gases, as a filter substrate, one of transition metal elements (Ti, Nb, Cr, Ta , V, Mo), 3 B or Group 4 B group element (Al, Si , Sn), and a ternary compound composed of three elements of carbon or nitrogen. Since the synthesized ternary compound easily grows in the A-axis direction during the synthesis process, it becomes a layered structure, and has a large number of atoms consisting of the c-plane and the side a-plane of steps (height: several tens to several hundreds of nm). It is characterized by the fine structure of the surface that the surface generates. It is possible to uniformly coat γ alumina, ceria, zirconia or their composite oxides on the surface by utilizing high wettability based on minute steps of micron to nano level formed on the surface. As a result, the amount of catalyst supported can be reduced.

The present invention has the following effects.
(1) Improved the performance and cost by improving the low thermal conductivity, low thermal shock resistance, low vibration damping and wettability for metal saving, which are the disadvantages of conventional cordierite or silicon carbide filters. Therefore, it is possible to provide a new exhaust gas purifying filter that makes it possible.
(2) By using a synthesized ternary compound as a filter base, it becomes possible to uniformly coat γ-alumina, ceria, zirconia, or a composite oxide thereof and a catalyst component on the surface. As a result, the amount of catalyst used can be greatly reduced.
(3) It is possible to provide a novel exhaust gas purification filter that can be suitably used as an exhaust gas purification filter for diesel engines and gasoline engines.
(4) The filter member of the present invention has high thermal conductivity, the catalyst activation time immediately after engine startup is shortened, and the amount of harmful substances contained in the exhaust gas can be reduced immediately after engine startup.

Next, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. In addition, Ti ₃ SiC ₂ was cited as an example, but other compounds such as Ti ₃ AlC ₂ and Ti ₂ Al could be synthesized.

Ti powder (purity 99.9%, particle diameter 150 μm or less), Si powder (99.9%, 10 μm or less), and TiC powder (99%, 2 to 5 μm) were mixed with Ti: Si: TiC = 2: 2: The mixture was weighed to a molar ratio of 3 and mixed with a turbula mixer in an argon atmosphere for 24 hours. After this mixed powder was compression molded at a pressure of 50 MPa, the compact was heated in a vacuum heat treatment furnace at 1500 ° C. for 2 hours to synthesize a substantially single-phase Ti ₃ SiC ₂ sintered body. FIG. 1 shows an X-ray diffraction pattern of the sintered body. It can be seen that single-phase Ti ₃ SiC ₂ was obtained.

  3 × 4 × 50mm from the sintered body material, and a groove is provided in the part about 5mm from the end. Using the groove, the wire is tied with platinum wire, and the sample is placed in the quartz core tube so that the sample is almost in the center. Hanging more. After heating to a predetermined temperature in a tubular furnace, it was held for 10 minutes. After heating and holding the sample, the sample was dropped into a water tank (water temperature 22 ° C.) placed 15 cm below and subjected to thermal shock. A sample was taken out and left in a drying furnace to sufficiently remove moisture, and then subjected to a bending test.

  FIG. 2 shows a change in strength after heating the sample to a predetermined temperature, dropping it into water, and applying thermal stress by rapid cooling. A similar test was performed using silicon carbide for comparison. From the results shown in the figure, it was found that in the comparative material (silicon carbide), the critical temperature difference ΔTc at which cracking occurs due to thermal stress generated on the surface during rapid cooling and the strength greatly deteriorates is around 350 ° C. On the other hand, in the sample of the present invention, it was found that there was almost no deterioration in strength even when the quenching temperature difference was 1400 ° C. This is because, unlike silicon carbide, in the sample of the present invention, plastic deformation occurs and thermal stress is relieved.

A substantially single phase Ti ₃ SiC ₂ sintered body was synthesized by the same method as described above. A γ-alumina aqueous slurry (1 g / 1 ml) having an average particle size of about several μm was prepared, and the developed material of the present invention having the same porosity of about 50%, cordierite (Comparative Example 1), silicon carbide (Comparative Example 2) 50 μL of the slurry was dropped onto the surface of) with a micropipette, and the spread at that time was compared. As a result, it was found that the slurry was most easily wetted with respect to the surface of the developed material of the present invention and could be coated uniformly. FIG. 3 shows the wettability test method and the wetting angle (degree) on the substrate surface of the alumina slurry.

  FIG. 4 shows the microstructure of the material according to the present invention. Whereas silicon carbide and cordierite have a smooth surface at a microscopic level, the material used in the present invention has many fine steps formed on the surface and has a stepped shape. I understand that. In general, the wettability of the liquid on the surface of the solid is evaluated by the contact angle θ, and the following relationship exists between the value and the surface energy of the solid, the liquid and the energy of the solid-liquid interface.

cos θ = (γ _S −γ _SL ) / γ _L
γ _SL = γ _S + γ _L -2 (γ _S '· γ _L ') ^1/2
γ _S : surface energy of solid γ _L : surface energy of liquid γ _SL : interface energy of solid liquid

On the other hand, when the surface multiplication factor is R (R> 1), cos θ _f = R · (γ _S −γ _SL ) / γ _L from the balance of energy.
It becomes. That is, when θ <90 on a smooth surface, it becomes easier to wet on a surface with fine steps.

  Ti powder (purity 99.9%, average particle diameter 10 μm), Si powder (99.9%, 10 μm or less), and TiC powder (99%, 2 to 5 μm) were mixed with Ti: Si: TiC = 2: 2: Weighed to a molar ratio of 3. 140 wt% of water was blended with respect to the total weight of the powder and mixed by a ball mill. Then, it was made to dry and the water | moisture content was removed. 10% of polyethylene powder (pore forming agent) with a particle size of 70 microns is added to 100% of the mixed powder, and 12% methylcellulose, 1.5% glycerin and 15% water are added as molding aids and pressurized. A molding composition was prepared by kneading for about 1 hour using a kneader.

  The obtained composition was formed into a honeycomb molded body using an extrusion molding machine provided with a honeycomb molding die. The honeycomb molded body had an outer diameter of 150 mm, a length of 200 mm, and a cell wall thickness of 0.2 mm (300 cpi). The ends of the exhaust gas inlet / outlet passage were alternately sealed (so-called plug type = wall flow type ceramic filter). This was dried and then fired at a maximum of 1600 ° C. in a vacuum atmosphere.

  As a result of observing pore portions of the obtained sintered body, it was confirmed that the pores having a diameter of about 15 microns as a central value were 50% in terms of porosity. The filter further supported platinum particles after supporting Ce-based compound particles as a co-catalyst. Here, the Ce compound functions as an oxygen storage / release material. Collection and regeneration tests were performed for 10,000 cycles in the bench test, and the filter was taken out and observed. However, there was no occurrence of cracks and the like, and the filter function was maintained. In the case of silicon carbide, it is widely known that the thermal shock resistance is poor and it is necessary to use a split type (see FIG. 5).

  A performance test was conducted using the same filter as above. Separately, an 800 cpi honeycomb having a cell thickness of about 50 microns was also produced. The size is the same as the above filter. These are not sealed. The honeycomb was loaded with γ-alumina and platinum particles by wash coating. Here, this honeycomb is an oxidation catalyst. The oxidation catalyst was placed in the front stage and the filter was placed in the rear in a half-like housing made of SUS. These were fixed using an interlam mat. Furthermore, the half-shaped casing was covered from above, and the mating surfaces were joined by welding. The obtained DPF was subjected to a bench test. For comparison, an integrated DPF having the same volume was used.

  FIG. 6 shows the PM collection efficiency, the change in pressure loss over time, and FIG. 7 shows the results of measuring the particle diameter of PM contained in the exhaust gas. In the data, the present invention is a DPF provided with a honeycomb composed of a ternary compound, and the comparative example is a normal wall flow type DPF. The DPF was installed in the exhaust pipe connecting the exhaust manifold and the muffler of the diesel engine, and PM purification of the exhaust gas discharged from the diesel engine was performed. As a result, as shown in FIG. 6, the present invention showed a higher purification rate and collection time than the conventional product. Moreover, according to this invention, it turned out that PM of fine particle can be purified compared with the conventional DPF.

  In the case of a honeycomb composed of a ternary compound, even if the porosity is the same, an ultrafine particle in which the substantial collection area is increased and the Brownian motion is dominant as compared with silicon carbide having a smooth surface. It becomes easy to collect. As a result, it is considered that the pressure loss is small and the collection performance including the ultrafine particles is improved.

Table 1, Ti as transition metal elements, Cr, Mo, 3 B or Group 4 Al as B element, Si, further to prepare a filter by ternary compound consisting of three elements of carbon or nitrogen, a γ-alumina slurry The result of putting together the state of the coating in the case of carrying a catalyst using a platinum solution after wash coating and the amount of platinum carried at that time is shown. As comparative examples, Comparative Example 1: SiC and Comparative Example 2: Cordierite were shown. In all cases, the porosity was in the range of 53 to 56%, which was an appropriate level for filters. First, in the present invention, each component is excellent in wettability with γ-alumina and has a relatively smooth surface after coating, whereas Comparative Examples 1 and 2 tend to be lumpy. Admitted.

  The obtained filter was fixed to the inside of the enclosure using an interlam mat, and a bench test was conducted using a diesel engine with a displacement of 2L. As a result of investigating the post-injection time required for regeneration, both the comparative example and the present invention are in the range of 5.0 to 5.5 seconds. Therefore, in the present invention, equivalent performance can be obtained even if the amount of platinum is reduced. I understood. In the case of the present invention, it is considered that the wettability with the slurry can be controlled by selecting the components, and the amount of the catalyst that does not function in the past has been reduced. As a result, it is considered that loss is reduced and the amount of catalyst particles is also reduced.

  The present invention relates to an exhaust gas purification filter and a method for producing the same, and according to the present invention, a high melting point required for diesel and gasoline engine exhaust gas purification filters, stability that does not decompose at high temperatures, high temperature strength, and high temperature acid resistance. Provided are a ternary compound filter having a chemical property, a thermal shock resistance, a high specific surface area, a low pressure loss, a narrow pore size distribution, a high thermal conductivity, a good catalyst wettability and a vibration damping property, and a method for producing the same. Can do. As a result, compared to conventional cordierite or silicon carbide filters, the catalyst activation time immediately after engine startup is shortened, and the amount of harmful substances contained in the exhaust gas can be reduced from the time of engine startup. In addition, exhaust noise can be reduced, and noise can be reduced. The present invention provides a filter with high thermal conductivity more than twice that of metallic titanium, thermal shock resistance with a temperature difference of 1400 ° C., and sufficient vibration damping, and a reduction in the amount of catalyst supported. It is highly technical as it provides new technologies and new products related to exhaust gas purification filters with new materials that enable higher performance and lower cost than conventional cordierite filters and silicon carbide filters. It has significance.

The X-ray diffraction pattern of a sintered compact is shown. The relationship between quenching temperature difference and intensity ratio is shown. The outline of the wettability test method and the wetting angle (degree) on the substrate surface of the alumina slurry are shown. 2 shows the microstructure of the ceramic material of the present invention. The difference in structure between the integrated filter and the split filter is shown. The relationship between collection time, PM collection efficiency, and pressure loss is shown. The PM particle number distribution is shown.

Claims (7)

In the exhaust gas purifying filter, the filter substrate is a transition metal element Ti, Nb, Cr, Ta, V, one of M o, of 3 B or Group 4 B group element Al, Si, of S n one, and ternary ternary compounds made filter substrate der Rukoto of pores with a controlled configured size or shape having therein a compound consisting of three elements of carbon or nitrogen in, and the Utilizing wettability based on the fine structure of the atomic surface generated on the surface of the ternary compound, the surface is coated with either γ-alumina, ceria, zirconia or a composite oxide thereof and a catalyst component Exhaust gas purification filter characterized by being supported . One of the transition metal elements: one 3 B or Group 4 B group element: element ratio of a ternary compound consisting of three elements carbon or nitrogen, in this order 3: 1: 2 or 2: 1: 1 Or the filter for exhaust gas purification of Claim 1 which is 4: 1: 3. One transition metal element, 3 a B group or a 4 B group element, a mixture of flour powder or whiskers or fibers ternary compound material consisting of three elements of carbon or nitrogen, by reacting by heating A method for producing a ternary compound for a filter, comprising producing a ternary compound having pores whose sizes and shapes are controlled inside . One transition metal element, 3 a B group or a 4 B group element, a mixture of powder or whiskers or fibers having a predetermined particle size distribution of the ternary compound material consisting of three elements of carbon or nitrogen, filter After forming into a shape, by heating, a ternary compound is synthesized and sintered to produce a filter base made of a ternary compound having pores whose size and shape are controlled inside. Manufacturing method of filter substrate for exhaust gas purification. A powder having a predetermined particle size distribution obtained by pulverizing and classifying the ternary compound produced by the method according to claim 3 is molded into a filter shape and then sintered to have pores whose size is controlled. The manufacturing method of the filter base material for exhaust-gas purification | cleaning of Claim 4 which manufactures the filter base material made from another ternary compound . The method for producing a filter base material for exhaust gas purification according to claim 4 or 5 , wherein Al or Si is further added as a fourth element for lowering a sintering temperature to the composition of the ternary compound raw material. An exhaust gas purification system characterized in that the surface of the filter base material according to any one of claims 4 to 6 is coated with any one of α-alumina, ceria, zirconia or a composite oxide thereof and supports a catalyst component. Method for manufacturing filters.