WO2007083779A1 - Catalyseur de purification de gaz d'échappement - Google Patents

Catalyseur de purification de gaz d'échappement Download PDF

Info

Publication number
WO2007083779A1
WO2007083779A1 PCT/JP2007/050857 JP2007050857W WO2007083779A1 WO 2007083779 A1 WO2007083779 A1 WO 2007083779A1 JP 2007050857 W JP2007050857 W JP 2007050857W WO 2007083779 A1 WO2007083779 A1 WO 2007083779A1
Authority
WO
WIPO (PCT)
Prior art keywords
exhaust gas
filter substrate
catalyst
alkali metal
cells
Prior art date
Application number
PCT/JP2007/050857
Other languages
English (en)
Inventor
Hitoshi Kato
Yoshitsugu Ogura
Original Assignee
Toyota Jidosha Kabushiki Kaisha
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyota Jidosha Kabushiki Kaisha filed Critical Toyota Jidosha Kabushiki Kaisha
Priority to BRPI0706869-7A priority Critical patent/BRPI0706869A2/pt
Priority to EP07713661A priority patent/EP1979070A1/fr
Priority to CA002635082A priority patent/CA2635082A1/fr
Publication of WO2007083779A1 publication Critical patent/WO2007083779A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/944—Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
    • B01D46/2403—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies characterised by the physical shape or structure of the filtering element
    • B01D46/2418—Honeycomb filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56—Platinum group metals
    • B01J23/58—Platinum group metals with alkali- or alkaline earth metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J33/00—Protection of catalysts, e.g. by coating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0242—Coating followed by impregnation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0244—Coatings comprising several layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0248—Coatings comprising impregnated particles

Definitions

  • the present invention relates to an exhaust gas-purifying catalyst capable of purifying particulate material (hereinafter, referred to as "PM") , which is contained in a diesel exhaust gas or the like and mainly contains carbon, from a low-temperature range.
  • the exhaust gas-purifying catalyst according to the present invention is particularly useful as a catalyst for purifying exhaust gas for diesel engines because it can purify not only PM, but also HC, CO, or NO x .
  • Known exhaust gas purifiers for diesel engines which have been developed up to date, are mainly classified into a trap type (wall flow structure) and an open type (straight flow structure) .
  • a trap type exhaust gas purifier a clogged honeycomb structure (a diesel PM filter (hereinafter, referred to as a "DPF") ) made of ceramic is known.
  • a DPF is known which includes a ceramic honeycomb structure with cells clogged at opposite ends of openings thereof in the form of a checkered pattern alternately.
  • the DPF includes inlet cells each clogged at an exhaust gas downstream side thereof, outlet cells each arranged adjacent to the inlet cells and clogged at an exhaust gas upstream side thereof, and cell partition walls partitioning the inlet cells and the outlet cells from each other.
  • exhaust gas is filtered by pores of the cell partition walls, which capture PM, so that emission of PM is suppressed.
  • Japanese Patent Publication No. 7-106290 discloses a filter catalyst, the filter catalyst comprises a coating layer made of alumina, etc. and formed on surfaces of cell partition walls of a DPF, and a catalytic metal such as platinum (Pt) supported on the coating layer.
  • a catalytic metal such as platinum (Pt) supported on the coating layer.
  • Japanese Patent Application Publication No. 9-094434 also discloses a filter catalyst wherein a coating layer supporting a catalytic metal is formed not only on cell partition walls, but also on pores of the cell partition walls. Since the catalytic metal is also supported in the pores of the cell partition walls, the catalytic metal is likely to contact the PM. The PM captured by the pores can also be oxidized and burnt.
  • Supporting alkali metal or alkaline earth metal on a coating layer of a filter catalyst, together with noble metal is also disclosed in Japanese Patent Application Publication No. 2003-049627 or Japanese Patent Application Publication No. 2003-049631. The alkali metal or alkaline earth metal forms a nitrate or sulfate in an exhaust gas.
  • the filter catalyst including the coating layer supporting alkali metal or alkaline earth metal, together with noble metal also has a problem in that a sufficient PM oxidation performance cannot be exhibited in a general operation range of about 400 0 C or below.
  • the present invention has been made in view of the above-mentioned problems, and it is an aspect of the invention to provide an exhaust gas-purifying catalyst which is capable of oxidizing PM even in a low-temperature range of 300 0 C or below and enhancing PM oxidation performance.
  • the present invention provides an exhaust gas-purifying catalyst comprising: a filter substrate having a wall flow structure, the filter substrate including inlet cells each clogged at an exhaust gas downstream side of the inlet cell, outlet cells each arranged adjacent to the inlet cells and clogged at an exhaust gas upstream side of the outlet cell, and porous cell partition walls partitioning the inlet cells and the outlet cells from each other and having a plurality of pores; and a catalyst bed formed on the cell partition walls, wherein the catalyst bed contains a porous oxide, a noble metal supported on the porous oxide, and an alkali metal supported on the porous oxide in an amount of 0.6 mole or more per IL of the filter substrate, and oxidizes particulate material (PM) , which mainly contains carbon, and is captured by the filter substrate, from a low-temperature range of 300 0 C or below.
  • the catalyst may further comprise a protection layer formed between the filter substrate and the catalyst bed, and made of an oxide reactable with the alkali
  • FIG. 1 is an explanation view illustrating a structure of an exhaust gas-purifying catalyst according to an exemplary embodiment of the present invention
  • FIG. 2 is a graph depicting a PM oxidation initiation temperature and a PM oxidation peak temperature
  • FIG. 3 is a graph depicting a relation between temperature and differential pressure
  • FIG. 4 is a graph depicting a relation between potassium supporting amount and PM oxidation initiation temperature.
  • FIG. 5 is an explanation view illustrating a structure of an exhaust gas-purifying catalyst according to another exemplary embodiment of the present invention.
  • the present invention provides an exhaust gas-purifying catalyst including a filter substrate and a- catalyst bed formed on cell partition walls of the filter substrate.
  • the filter substrate has a wall flow structure similar to a conventional DPF including inlet cells each clogged at an exhaust gas downstream side thereof, outlet cells each arranged adjacent to the inlet cells and clogged at an exhaust gas upstream side thereof, and porous cell partition walls partitioning the inlet cells and the outlet cells from each other and having a plurality of pores.
  • the filter substrate may be formed of a metal foam or a heat-resistant non-woven fabric.
  • the filter substrate may also be made of heat-resistant ceramics such as cordierite or silicon carbide.
  • a clayey slurry containing cordierite powder as a major component thereof is prepared. The prepared slurry is shaped by extrusion, and is then calcined. In place of the cordierite powder, a mixture of alumina powder, magnesia powder and silica powder having the same composition as the cordierite may be prepared. Openings of the cells at one end of the filter substrate are clogged in the form of a checkered pattern by clayey slurries having a shape similar to that of the cell openings, respectively.
  • a filter substrate having a honeycomb structure can be fabricated.
  • the cross-sectional shapes of the inlet cells and outlet cells may be triangular, square, hexagonal, circular, etc. Of course, they are not limited to such shapes.
  • the cell partition walls have.a porous structure allowing an exhaust gas to pass therethrough. In order to form pores in the cell partition walls, combustible powder such as carbon powder, wood powder, starch, or resin powder is mixed with the slurry.
  • pores are formed in the cell partition walls. It is possible to control the diameter and volume of the pores by adjusting the size and content of the combustible powder.
  • the inlet cells and outlet cells are communicated with each other by the pores . Accordingly, although PM is captured in the pores, gas can flow from the inlet cells to the outlet cells via the pores.
  • the cell partition walls have a porosity of 40% to 70%.
  • the pores preferably have an average diameter of 10 ⁇ m to 40 ⁇ m.
  • the cell partition walls have the porosity and average pore diameter ranging as described above, it is possible to suppress an- increase in pressure loss even when the catalyst bed is formed to range from 100g/L to 200g/L. It is also possible to suppress a decrease in strength. Thus, capture of PM can be more effectively achieved.
  • the catalyst bed is provided at the cell partition walls of the filter substrate.
  • the catalyst bed may be formed only on the surfaces of the cell partition walls, it is preferred that the catalyst bed be also formed on the surfaces of the pores in the cell partition walls.
  • the catalyst bed contains a porous oxide, noble metal supported on the porous oxide, and alkali metal supported on the porous oxide.
  • the porous oxide may include alumina, zirconia, titania, silica, or ceria conventionally used as a catalyst support, or a composite oxide or mixture of at least two of the catalyst supports. Among these materials, ⁇ -alumina having a large specific surface area is preferable.
  • the noble metal supported on the porous oxide may be selected from Pt, Pd, Rh, Ir, Ru, etc. Among these elements, it is preferable to select Pt, which exhibits a high oxidation activity to PM.
  • the supported amount of the noble metal ranges from O.lg to 5g per IL of the filter substrate. When the supported amount of the noble metal is less than the above range, it is impractical due to an excessively low activity. On the other hand, when the supported amount of the noble metal is more than the above range, saturated activity is exhibited, and the costs are increased.
  • the supporting of the noble metal may be achieved by an adsorption supporting method, a impregnating supporting method, or the like using a solution containing a nitrate of the noble metal dissolved therein.
  • the alkali metal supported on the porous oxide Na, K, Li, Cs, etc. maybe used.
  • K is preferable which exhibits a particularly-high oxidation activity to PM.
  • the supported amount of the alkali metal is 0.6 mole or more per IL of the filter substrate.
  • the supported amount of the alkali metal is less than the above range, it is difficult to initiate oxidation of PM at a temperature of 300 0 C or below.
  • the supported amount of the alkali metal have an upper limit of about 2 moles per IL of the filter substrate, for purification of exhaust gases of vehicles.
  • the supported amount of the alkali metal exceeds the upper limit, a degradation in the activity of the noble metal occurs, thereby degrading the performance capable of purifying HC, CO, NO x , etc.
  • the catalyst bed is formed by preparing a slurry of the porous oxide powder with a binder ingredient such as an alumina sol and water, applying the slurry to the cell partition walls, and calcining the applied slurry, thereby forming a coating layer.
  • a slurry may be prepared using catalyst powder prepared by previously supporting the noble metal on the porous oxide powder.
  • the supporting of the alkali metal may be performed after the formation of the catalyst bed using the prepared slurry.
  • the application of the slurry to the cell partition walls may be achieved using a general dipping method. However, it is preferable to remove a surplus of the slurry filled in the pores, while forcibly filling the slurry in the pores of the cell partition walls by air blow or air suction.
  • the formation amount of the coating layer or catalyst bed preferably ranges from 3Og to 200g per IL of the filter substrate.
  • the formation amount of the coating layer or catalyst bed is less than 30g/L, it is impossible to prevent a degradation in the durability of the noble metal.
  • the formation amount of the coating layer or catalyst bed exceeding 200g/L is impractical due to an excessively high pressure loss.
  • a protection layer made of an oxide reactable with the alkali metal is formed between the filter substrate and the catalyst bed.
  • the protection layer functions to suppress the alkali metal supported in the catalyst bed from migrating to the filter substrate in a high-temperature atmosphere, and thus, to suppress a degradation in the strength of the filter substrate. It is also possible to suppress a degradation in the concentration of the alkali metal in the catalyst bed caused by the migration of the alkali metal to the filter substrate. Accordingly, a degradation in PM oxidation activity can be suppressed.
  • Examples of the oxide reactable with the alkali metal may be TiO 2 , SiO 2 , Al 2 O 3 , B 2 O 3 , P 2 O 5 , etc.
  • the formation amount of the protection layer corresponds to a thickness of O.OOl ⁇ m to 5 ⁇ m or ranges from Ig to 5Og per IL of the filter substrate.
  • the formation amount of the protection layer is less than the above range, it is difficult to suppress the migration of the alkali metal to the filter substrate.
  • the formation amount of the protection layer exceeding the above range is impractical due to an excessive increase in pressure loss.
  • alkali metal is supported in an amount of 0.6 mole or more per IL of the filter substrate.
  • PM can be oxidized, is lowered, so that PM can be oxidized at a low temperature of 300 °C or below.
  • the exhaust gas-purifying catalyst according to the present invention can purify PM by oxidation from a low-temperature range lower than 300 0 C, so that the PM oxidation performance can be considerably enhanced. As a result, accumulation of PM is suppressed, thereby suppressing an increase in pressure loss. Thus, continuous regeneration of the catalyst for PM purification can be stably achieved, so that it is possible to prevent defects such as cracks caused by forced regeneration.
  • a protection layer made of an oxide reactable with the alkali metal is formed between the filter substrate and the catalyst bed, as described above, it is possible to suppress the alkali metal from migrating to the filter substrate by the protection layer.
  • FIG. 1 illustrates an exhaust gas-purifying catalyst according to this example.
  • This catalyst includes: a filter substrate 1 including inlet cells 10 each clogged at an exhaust gas downstream side thereof, outlet cells 11 each arranged adjacent to the inlet cells, and clogged at an exhaust gas upstream side thereof, and porous cell partition walls 12 partitioning the inlet cells 10 and the outlet cells 11 from each other; and a catalyst bed 2 formed on the surfaces of the cell partition walls 12 and on the surfaces of pores formed in the cell partition walls 12.
  • a commercially-available DPF made of cordierite is used.
  • This DPF has a test piece size (35cc, 30mm (diameter) x 50mm (length) ) , and a porosity of 60% to 67%, a pore volume of 0.58cc/g to 0.65cc/g, and an average pore diameter of 25 ⁇ m to 35 ⁇ m at the cell partition walls 12.
  • a detailed description of the structure of the catalyst bed 2 will be given through a description of a method for manufacturing the catalyst bed 2.
  • a slurry is prepared by mixing catalyst powder previously supporting Pt with Y-AI 2 O 3 powder (specific surface area of 220m 2 /g) , together with an alumina sol and ion-exchanged water, such that the mixture has a viscosity of lOOcps or less.
  • the prepared slurry is milled such that solid grains thereof have an average diameter of l ⁇ m or less . Thereafter, the filter substrate 1 is dipped in the slurry, to allow the slurry to be introduced into the cells.
  • the slurry is then sucked from the end of the filter substrate 1 opposite to the dipped end in a state in which the filter substrate 1 has been upwardly taken out of the slurry, to remove a surplus of the slurry from the filter substrate 1.
  • the filter substrate 1 is calcined at 500 0 C for 3 hours. This procedure is performed two times, in order to adjust the formation of the coating layer such that the coating layer is formed on the inlet cells 10 and outlet cells 11 in substantially same amounts, respectively.
  • the formation amount of the coating layer is 15Og per IL of the filter substrate 1.
  • the coating layer is formed on the surfaces of the inlet cells 10 and outlet cells 11 and on the surfaces of the pores.
  • the Pt supporting amount of the coating layer is 3g/L.
  • Example 2 An exhaust gas-purifying catalyst according to Comparative Example 1 is prepared in the same manner as Example 1, except that the supported amount of Li is 0.3 mole/L. (Example 2) [0035] An exhaust gas-purifying catalyst according to Example
  • Example 2 is prepared in the same manner as Example 1, except that a potassium acetate aqueous solution is used in place of the lithium acetate aqueous solution, and K is supported in the coating layer in an amount of 0.6 mole/L.
  • Example 3 is prepared in the same manner as Example 1, except that a potassium acetate aqueous solution is used in place of the lithium acetate aqueous solution, and K is supported in the coating layer in an amount of 1.5 mole/L.
  • An exhaust gas-purifying catalyst according to Comparative Example 2 is prepared in the same manner as Example 1, except that a potassium acetate aqueous solution is used in place of the lithium acetate aqueous solution, and K is supported in the coatinq layer in an amount of 0.3 mole/L.
  • An exhaust qas-purifying catalyst according to Comparative Example 3 is prepared in the same manner as Example 1, except that the alkali metal is not supported.
  • An exhaust gas-purifying catalyst according to Comparative Example 4 is prepared in the same manner as Example 1, except that a barium acetate aqueous solution is used in place of the lithium acetate aqueous solution, and Ba is supported in the coating layer in an amount of 0.3 mole/L.
  • Each PM-attached catalyst was loaded in an evaluation apparatus, and was then subjected to an increase in temperature from room temperature to a temperature of 600 0 C at a rate of 10°C/min under the condition in which a model gas consisting of 10% of O 2 , 500 ppm of NO, and the balance of N 2 flowed through the catalyst at a flow rate of 0.03m 3 /min. •
  • the catalysts of the examples exhibit a low PM oxidation initiation temperature and a low PM oxidation peak temperature, as compared to the catalysts of Comparative Examples 1 and 2. That is, it can be clearly seen that the catalysts of the examples can oxidize PM from a low-temperature range, and exhibit a high PM oxidation activity in the low-temperature range.
  • the supported amount of K is preferable to be 1.5g/L, as compared to 0.6g/L, because the catalyst of Example 3 exhibits a lower temperatures than that of Example 2. Also, it can be seen that K is more preferable than Li because the catalyst of Example 2 exhibitsa lower temperatures than that of Example 1. On the other hand, it can be seen that Ba representing the alkaline earth metal of Comparative Example 4 has no effect obtained in a supported state.
  • a plurality of catalysts were prepared in the same manner as that of Example 2, except that they had different K supporting amounts within a range of 0 mole/L to 1.5 mole/L, respectively.
  • a PM oxidation initiation temperature was measured in accordance with the above-described method.
  • FIG. 4 depicts the measured results.
  • FIG. 5 illustrates an exhaust gas-purifying catalyst according to this example.
  • the catalyst according to this example includes: a filter substrate 1 including inlet cells 10 each clogged at an exhaust gas downstream side thereof, outlet cells 11 each arranged adjacent to the inlet cells and clogged at an exhaust gas upstream side thereof, and cell partition walls 12 partitioning the inlet cells 10 and the outlet cells 11 from each other; a protection layer 3 formed on the surfaces of the cell partition walls 12 and on the surfaces of pores formed in the cell partition walls 12; and a catalyst bed 2 formed on the 'surface of the protection layer 3.
  • This catalyst is identical to that of Example 2, except that the catalyst includes the protection layer 3. Accordingly, a detailed description of the structure of the catalyst bed 2 will be given through a description of a method for manufacturing the catalyst bed 2.
  • the filter substrate 1 is dipped in a slurry, in which a silica sol is distributed, to allow the slurry to be introduced into the cells.
  • the slurry is then sucked from the end of the filter substrate 1 opposite to the dipped end in a state in which the filter substrate 1 has been upwardly taken out of the slurry, to remove a surplus of the slurry from the filter substrate 1.
  • the filter substrate 1 is calcined at 500 0 C for 3 hours. This procedure is performed two times, in order to adjust the formation of the protection layer such that the protection layer is formed on the inlet cells 10 and outlet cells 11 in substantially same amounts, respectively.
  • the formation amount of the protection layer is 2Og per IL of the filter substrate 1 (substantially a thickness of I ⁇ m) .
  • the catalyst bed 2 is formed in the same manner as that of Example 2. (Example 5)
  • the protection layer 3 which is made of TiO 2 is formed in the same manner as that of Example 4, except that a titania sol is used in place of the silica sol. Thereafter, the catalyst bed 2 is formed in the same manner as that of Example 2. (Example 6)
  • the protection layer 3 which is made of Al 2 O 3 is formed in the same manner as that of Example 4, except that an" alumina sol is used in place of the silica sol. Thereafter, the catalyst bed 2 is formed in the same manner as that of Example 2.
  • Experimental Example 4 • Evaluation>
  • a high-temperature durability test was carried out by maintaining the catalyst in a heated state in an electric furnace at 700 0 C for 10 hours. Thereafter, the above-described test was carried out to measure a PM oxidation initiation temperature.
  • the strength of the filter substrate 1 was measured by Autograph. Based on the measured results, the catalysts were evaluated to be ⁇ O" when exhibiting a compressive strength of more than 2 MPa, N ⁇ ⁇ " when exhibiting a compressive strength ranging from 1.5 MPa to 2 MPa, or "X" when exhibiting a compressive strength of less than 1.5 MPa. Table 1 shows the evaluated results.
  • Example 2 exhibits a degradation in substrate strength after the high-temperature durability test.
  • a degradation in substrate strength can be suppressed by forming a protection layer, as in Examples 4 to 6.
  • a protection layer made of SiO 2 or TiO 2 is formed, results similar to those of Comparative Example 3 supporting no K are obtained. In this case, accordingly, it is possible to greatly suppress a degradation in substrate strength.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • General Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Analytical Chemistry (AREA)
  • Biomedical Technology (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Health & Medical Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Geometry (AREA)
  • Catalysts (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Processes For Solid Components From Exhaust (AREA)
  • Filtering Of Dispersed Particles In Gases (AREA)

Abstract

Catalyseur de purification de gaz d'échappement, qui comprend un substrat filtrant à structure de flux de paroi et un lit catalytique formé sur des parois de séparation de cellule de ce substrat. Le lit catalytique comprend un oxyde poreux, un métal noble soutenu sur l'oxyde poreux, et enfin un métal alcalin soutenu sur l'oxyde poreux en quantité de 0,6 mole ou plus par litre de substrat filtrant. Étant donné qu'une grande quantité de métal alcalin est soutenue, le métal alcalin peut entrer en contact avec un matériau particulaire contenant essentiellement du carbone. En conséquence, la température d'oxydation du matériau particulaire peut être abaissée. Ainsi, il est possible d'oxyder ce matériau même à une température faible de 300° C ou moins.
PCT/JP2007/050857 2006-01-17 2007-01-15 Catalyseur de purification de gaz d'échappement WO2007083779A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BRPI0706869-7A BRPI0706869A2 (pt) 2006-01-17 2007-01-15 Catalisador de purificação de gás de exaustão
EP07713661A EP1979070A1 (fr) 2006-01-17 2007-01-15 Catalyseur de purification de gaz d'échappement
CA002635082A CA2635082A1 (fr) 2006-01-17 2007-01-15 Catalyseur de purification de gaz d'echappement

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2006-008894 2006-01-17
JP2006008894A JP2007190459A (ja) 2006-01-17 2006-01-17 Ｐｍ浄化用触媒

Publications (1)

Publication Number Publication Date
WO2007083779A1 true WO2007083779A1 (fr) 2007-07-26

Family

ID=38016781

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2007/050857 WO2007083779A1 (fr) 2006-01-17 2007-01-15 Catalyseur de purification de gaz d'échappement

Country Status (8)

Country Link
EP (1) EP1979070A1 (fr)
JP (1) JP2007190459A (fr)
KR (1) KR20080078894A (fr)
CN (1) CN101374586A (fr)
BR (1) BRPI0706869A2 (fr)
CA (1) CA2635082A1 (fr)
RU (1) RU2008133623A (fr)
WO (1) WO2007083779A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3673996A4 (fr) * 2017-09-21 2020-10-07 Cataler Corporation Catalyseur pour la purification des gaz d'échappement

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008039684A1 (de) * 2008-08-26 2010-03-04 Schott Ag Thermokatalytische Beschichtung
JP6581934B2 (ja) * 2016-03-24 2019-09-25 日本碍子株式会社 ハニカムフィルタ
JP6529639B1 (ja) * 2018-05-17 2019-06-12 エヌ・イーケムキャット株式会社 排ガス浄化触媒の製造方法
CN110201666B (zh) * 2019-06-20 2022-01-25 中自环保科技股份有限公司 一种汽油机颗粒捕集催化剂及其制备方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030083197A1 (en) * 2001-01-19 2003-05-01 Naomi Noda Catalyst element
EP1319436A1 (fr) * 2000-09-08 2003-06-18 Ngk Insulators, Ltd. Proc d de production d'un corps catalyseur et support porteur d'alumine
EP1350554A1 (fr) * 2002-03-19 2003-10-08 Toyota Jidosha Kabushiki Kaisha Catalyseur pour purifier de gaz d'échappement

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4548968B2 (ja) * 2000-06-05 2010-09-22 株式会社日本自動車部品総合研究所 セラミック担体およびセラミック触媒体
JP3748202B2 (ja) * 2000-09-26 2006-02-22 トヨタ自動車株式会社 排ガス浄化用触媒
JP3855777B2 (ja) * 2002-01-23 2006-12-13 トヨタ自動車株式会社 内燃機関のパティキュレートフィルタ
JP3933015B2 (ja) * 2002-09-03 2007-06-20 三菱自動車工業株式会社 内燃機関の排気浄化装置
JP4567285B2 (ja) * 2002-11-22 2010-10-20 日本碍子株式会社 排ガス浄化用触媒体
JP2004202427A (ja) * 2002-12-26 2004-07-22 Toyota Motor Corp 排ガス浄化フィルタ触媒

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1319436A1 (fr) * 2000-09-08 2003-06-18 Ngk Insulators, Ltd. Proc d de production d'un corps catalyseur et support porteur d'alumine
US20030083197A1 (en) * 2001-01-19 2003-05-01 Naomi Noda Catalyst element
EP1350554A1 (fr) * 2002-03-19 2003-10-08 Toyota Jidosha Kabushiki Kaisha Catalyseur pour purifier de gaz d'échappement

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3673996A4 (fr) * 2017-09-21 2020-10-07 Cataler Corporation Catalyseur pour la purification des gaz d'échappement
US10981113B2 (en) 2017-09-21 2021-04-20 Cataler Corporation Exhaust gas purification catalyst body

Also Published As

Publication number Publication date
CN101374586A (zh) 2009-02-25
BRPI0706869A2 (pt) 2011-04-12
KR20080078894A (ko) 2008-08-28
EP1979070A1 (fr) 2008-10-15
CA2635082A1 (fr) 2007-07-26
JP2007190459A (ja) 2007-08-02
RU2008133623A (ru) 2010-02-27

Similar Documents

Publication Publication Date Title
KR100545299B1 (ko) 배기가스 정화용 필터 촉매 및 이의 제조 방법
JP4845795B2 (ja) 排ガス浄化フィルタとその製造方法
JP5237630B2 (ja) ハニカム構造体
EP1371826B1 (fr) Filtre catalytique pour la purification des gaz d'échappement
JP5767770B2 (ja) 極薄触媒酸化塗膜を有するディーゼル粉塵フィルター
JP4393039B2 (ja) 触媒つきフィルタ、その製造方法及び排気ガス浄化システム
US20070140928A1 (en) Low pressure drop coated diesel exhaust filter
KR20070067098A (ko) 표면 필터를 미분 고형물로 피복하는 방법, 당해 방법으로수득한 필터 및 당해 필터의 용도
KR101457238B1 (ko) 개선된 매연 필터
JP2003080080A (ja) セラミックフィルタおよび触媒付セラミックフィルタ
KR20020048433A (ko) 촉매 및 그의 제조방법
JP2009160547A (ja) 排ガス浄化用触媒とその製造方法
JP4006645B2 (ja) 排ガス浄化装置
WO2007083779A1 (fr) Catalyseur de purification de gaz d'échappement
JP2006231116A (ja) 排ガス浄化フィルタ触媒
JP2005248726A (ja) 排ガス浄化用フィルタ触媒
JP2001314764A (ja) 触媒およびその製造方法
JP2007117954A (ja) ディーゼル排ガス浄化用触媒
JP5502885B2 (ja) 軽油成分の燃焼に適した酸化触媒
JP4218559B2 (ja) ディーゼル排ガス浄化装置
JP2009247995A (ja) 排ガス浄化用触媒及びその製造方法
JP2006159020A (ja) 排ガス浄化フィルタ及び排ガス浄化触媒
JP5524820B2 (ja) パティキュレート燃焼触媒、その製造方法、パティキュレートフィルター及びその製造方法
JP2006007100A (ja) 排ガス浄化フィルタ
JP5242214B2 (ja) ハニカム構造体およびそのハニカム構造体からなる触媒体

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2007713661

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 2635082

Country of ref document: CA

WWE Wipo information: entry into national phase

Ref document number: 6147/DELNP/2008

Country of ref document: IN

WWE Wipo information: entry into national phase

Ref document number: 1020087017134

Country of ref document: KR

WWE Wipo information: entry into national phase

Ref document number: 200780003277.8

Country of ref document: CN

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2008133623

Country of ref document: RU

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: PI0706869

Country of ref document: BR

Kind code of ref document: A2

Effective date: 20080715