JP2003170056A - Exhaust gas cleaning catalyst and exhaust gas cleaning material using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust gas cleaning catalyst having high exhaust gas cleaning efficiency and an exhaust gas cleaning material extremely excellent in durability and economical efficiency. <P>SOLUTION: The exhaust gas cleaning catalyst contains an inorganic oxide having heat resistance, a transition metal oxide catalyst layer supported on the surface of the inorganic oxide, a first catalyst having a noble metal layer and a second catalyst having a sulfate of at least one kind of an alkali metal. The exhaust gas cleaning material has a three-dimensional structure having heat resistance, the inorganic oxide having heat resistance supported on the surface of the three-dimensional structure, the transition metal oxide catalyst layer supported on the surface of the inorganic oxide and a layer of an exhaust gas cleaning catalyst containing the first catalyst having a noble metal layer and the second catalyst having at least one kind of an alkali metal sulfate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to particulates (solid carbon fine particles, liquid or solid high molecular weight hydrocarbon fine particles, hereinafter, abbreviated as PM) contained in exhaust gas discharged from a diesel engine. There is)
TECHNICAL FIELD The present invention relates to an exhaust gas purification catalyst for burning exhaust gas to purify exhaust gas and an exhaust gas purification material using the same.

[0002]

2. Description of the Related Art In recent years, the particulates emitted from diesel engines have a particle size of 1 micron or less, and are easily suspended in the atmosphere and easily taken into the human body by breathing. It has become clear that carcinogenic substances such as the above are contained, and their effects on the human body have become a serious problem.
For this reason, the emission control of particulates emitted from diesel engines has been further strengthened, and accordingly, exhaust gas purifying catalysts and exhaust gas purifying materials that can efficiently remove particulates are desired.

Conventionally, as one of the methods for removing particulates from exhaust gas, an exhaust gas purifying material composed of a heat-resistant three-dimensional structure is used to collect particulates in the exhaust gas, resulting in an increase in back pressure. After that, there is a method in which the exhaust gas purifying body is heated by a heating means such as a burner or an electric heater, the deposited particulates are burned, converted into carbon dioxide gas, and discharged to the outside.

However, the above method has a problem that the combustion temperature of the particulates is high and a large amount of energy is required to burn and remove the collected particulates and regenerate the filter. It was
Further, there is a problem that the filter is melted and broken due to combustion in a high temperature range and its reaction heat. Furthermore,
Since a special device is required, there is a problem that the purification device becomes large-sized and costly.

On the other hand, there is a method in which a catalyst is used to cause a combustion reaction of fine particles by a catalytic action, and combustion regeneration is performed at a temperature of exhaust gas in exhaust gas without using a heating means such as a heater.

As the catalyst-supported exhaust gas purifying material, there is a heat-resistant three-dimensional structure carrying an exhaust gas purifying catalyst composed of a metal oxide or the like. The particulates collected here are exhaust gas purifying materials. The catalytic action of the catalyst for use enables combustion at a lower temperature.

If the particulates can be burned at the exhaust gas temperature by using the exhaust gas purifying material carrying such an exhaust gas purifying catalyst, it is not necessary to dispose the heating means in the exhaust gas purifying apparatus, and the exhaust gas purifying apparatus is not required. The configuration can be simplified.

However, at present, it is difficult for an exhaust gas purifying material carrying an exhaust gas purifying catalyst to sufficiently burn particulates at the exhaust gas temperature, and it is essential to use it together with a heating means. Therefore, development of an exhaust gas purifying catalyst and an exhaust gas purifying material carrying an exhaust gas purifying catalyst having high catalytic activity capable of burning particulates at a lower temperature is desired.

It has been known so far that catalysts using metal oxides such as copper and vanadium have relatively high activity as exhaust gas purifying catalysts.

For example, Japanese Patent Application Laid-Open No. 58-143840 (hereinafter referred to as "A") describes "At least one selected from copper and its compounds, and a metal and its compounds capable of taking a plurality of oxidation states. A catalyst for purifying particulates in combination with at least one of the above is disclosed.

JP-A-58-174236 (hereinafter, referred to as
JP-B-2) discloses a "catalyst for purifying particulates in exhaust gas consisting of at least one selected from vanadium and vanadium compounds".

Japanese Examined Patent Publication No. 4-42063 (hereinafter referred to as "Cha") describes "Exhaust gas purifying catalyst in which an oxide of an alkali metal and a noble metal are added to a metal oxide such as copper, manganese, molybdenum, and a method for producing the same. Is disclosed.

[0013]

However, the above conventional exhaust gas purifying catalyst and exhaust gas purifying material have the following problems.

(1) In the exhaust gas purifying catalysts described in the publications A and B, since the catalytic activity of the exhaust gas purifying catalyst is not high enough to burn the particulates sufficiently at a low exhaust gas temperature, the exhaust gas purifying material There is a problem that the particulates collected in the above cannot be combusted at the exhaust gas temperature, and it is indispensable to use them together with a heating means.

(2) The exhaust gas-purifying catalyst described in Japanese Patent Publication (C) uses an alkali metal oxide in the structure of the exhaust gas-purifying catalyst. However, the alkali metal oxide is inferior in heat resistance and is a heat of exhaust gas. Therefore, there is a problem in that the particles are scattered or react with other catalyst components.

(3) The exhaust gas-purifying catalyst described in Japanese Patent Publication No. 3 (c) has a problem that it is poisoned by the sulfur oxides contained in the exhaust gas and the catalytic activity is lowered.

The present invention solves the above-mentioned conventional problems. It has a high catalytic activity for particulate combustion and can sufficiently exhibit its respective catalytic properties, and at the same time as the exhaust gas temperature, the particulates are sufficiently provided. An object of the present invention is to provide an exhaust gas purifying catalyst that can be removed by combustion and has a high exhaust gas purification rate, and an exhaust gas purifying material that can burn and remove particulates with extremely high efficiency and that is extremely excellent in durability and economy. .

[0018]

In order to solve the above problems, an exhaust gas purifying catalyst of the present invention comprises a heat resistant inorganic oxide and a transition metal oxide catalyst layer and a noble metal supported on the surface of the inorganic oxide. A first catalyst having a layer, a second catalyst having at least one alkali metal sulfate,
It has a structure containing.

Thus, by allowing the catalysts having different functions to exist, it becomes possible to sufficiently bring out different catalyst characteristics, prevent deterioration of activity, and obtain a highly active exhaust gas purifying catalyst. it can.

Further, by forming a catalyst component on the surface of the heat-resistant inorganic oxide, the catalyst surface area is increased, and as a result, the number of contact points with particulates in diesel exhaust gas is increased, and a highly active exhaust gas purification catalyst is obtained. Can be obtained.

The exhaust gas purifying material of the present invention is a heat-resistant three-dimensional structure, and a heat-resistant inorganic oxide and a transition carried on the surface of the inorganic oxide, which is formed on the three-dimensional structure. First having metal oxide catalyst layer and noble metal layer
And a layer of an exhaust gas purifying catalyst containing the second catalyst containing at least one kind of alkali metal sulfate.

Thus, by allowing each catalyst having a different function to exist, the reaction between the heat-resistant three-dimensional structure and the catalyst component can be suppressed, and a highly active exhaust gas purification material can be obtained.

Further, it is possible to obtain an exhaust gas purifying material which can reduce the required amount of noble metal, realize low cost, and is excellent in economic efficiency.

Further, the pressure loss of the filter can be suppressed and more catalyst components can be supported.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The exhaust gas purifying catalyst according to claim 1 of the present invention comprises a heat-resistant inorganic oxide, and a transition metal oxide catalyst layer and a noble metal layer carried on the surface of the inorganic oxide. It has a structure containing a first catalyst and a second catalyst containing at least one kind of alkali metal sulfate.

With this configuration, the following effects can be obtained.

(1) By forming a catalyst component on the surface of a heat-resistant inorganic oxide, the catalyst surface area is increased, and as a result, the number of contact points with particulates in diesel exhaust gas is increased, resulting in highly active exhaust gas. A purification catalyst can be obtained.

(2) By forming a catalyst component on the surface of a heat-resistant inorganic oxide, the required amount of the catalyst can be reduced, and an exhaust gas purifying catalyst can be obtained at low cost, which is economical. Excel.

(3) By individually providing a catalyst in which a transition metal oxide and a noble metal are supported on a heat-resistant inorganic oxide and an alkali metal sulfate catalyst, the function of each catalyst can be brought out. The catalytic activity can be increased.

(4) The transition metal oxide and the noble metal and the alkali metal sulfate are provided by individually providing a catalyst in which a transition metal oxide and a noble metal are supported on a heat-resistant inorganic oxide and an alkali metal sulfate catalyst. The necessary and sufficient amount of salt can be reduced, and an exhaust gas purification catalyst can be obtained at low cost, which is excellent in economic efficiency.

(5) By providing a catalyst in which a transition metal oxide and a noble metal are supported on a heat-resistant inorganic oxide and a catalyst for an alkali metal sulfate, respectively, as seen in particulate combustion, etc. It is possible to prevent the catalysts from reacting with each other due to heat and sufficiently exhibit different catalyst characteristics, and it is possible to prevent deterioration of catalyst activity and improve durability.

The exhaust gas purifying catalyst according to claim 2 of the present invention is a heat-resistant inorganic oxide, a transition metal oxide catalyst first layer supported on the surface of the inorganic oxide, and a transition metal oxide. It has a structure containing a first catalyst having a noble metal catalyst second layer as an upper layer of the catalyst first layer and a second catalyst having at least one alkali metal sulfate.

With this configuration, in addition to the function of claim 1,
The following effects are obtained.

(1) By locating the noble metal catalyst layer having a function of purifying gas components in diesel exhaust gas above the transition metal oxide catalyst layer having a function of purifying solid components in diesel exhaust gas, It is possible to obtain a highly active exhaust gas purifying catalyst having a function of purifying both a gas component and a solid component in exhaust gas at the same time.

The exhaust gas purifying catalyst according to claim 3 of the present invention comprises at least a heat-resistant inorganic oxide, a first catalyst having a transition metal oxide and a noble metal supported on the surface of the inorganic oxide, and And a second catalyst having one type of alkali metal sulfate.

With this configuration, the following effects can be obtained.

(1) By forming a catalyst component on the surface of a heat-resistant inorganic oxide, the catalyst surface area is increased, and as a result, the number of contact points with particulates in diesel exhaust gas is increased, resulting in highly active exhaust gas. A purification catalyst can be obtained.

(2) By forming a catalyst component on the surface of a heat-resistant inorganic oxide, the required amount of the catalyst can be reduced, and an exhaust gas purifying catalyst can be obtained at low cost, which is economical. Excel.

(3) By individually providing a catalyst in which a transition metal oxide and a noble metal are supported on a heat-resistant inorganic oxide and an alkali metal sulfate catalyst, the function of each catalyst can be brought out. The catalytic activity can be increased.

(4) The transition metal oxide, the noble metal and the alkali metal sulfate are provided by individually providing a catalyst in which a transition metal oxide and a noble metal are supported on a heat-resistant inorganic oxide and an alkali metal sulfate catalyst. The necessary and sufficient amount of salt can be reduced, and an exhaust gas purification catalyst can be obtained at low cost, which is excellent in economic efficiency.

(5) By providing a catalyst in which a transition metal oxide and a noble metal are supported on an inorganic oxide having heat resistance and a catalyst for an alkali metal sulfate, respectively, as seen in the case of particulate combustion, etc. It is possible to prevent the catalysts from reacting with each other due to heat and sufficiently exhibit different catalyst characteristics, and it is possible to prevent deterioration of catalyst activity and improve durability.

An exhaust gas purifying catalyst according to a fourth aspect of the present invention is the exhaust gas purifying catalyst according to the first to third aspects, wherein the noble metal contains Pt.

With this configuration, the following actions can be obtained in addition to the actions of the first to third aspects.

(1) Since the noble metal contains Pt, S other than the carbon component in the particulates by the noble metal catalyst is used.
The OF component and the like can be burned and purified most efficiently and stably, and the exhaust gas purification capability is extremely excellent.

The exhaust gas purifying catalyst according to claim 5 of the present invention is the exhaust gas purifying catalyst according to any one of claims 1 to 4, wherein the transition metal oxide is Cu,
At least one selected from Mn, Co, V, Mo, W
It has a structure containing a kind of metal oxide.

With this configuration, the following actions can be obtained in addition to the actions of the first to fourth aspects.

(1) The oxide of the transition metal is Cu, Mn, C
Since it contains at least one metal oxide selected from o, V, Mo and W, it is possible to obtain an exhaust gas purifying catalyst having a high catalytic activity when burning particulates.

The exhaust gas purifying catalyst according to claim 6 of the present invention is the exhaust gas purifying catalyst according to any one of claims 1 to 5, wherein the transition metal oxide is Cu.
It has a structure containing at least one Cu oxide selected from O, Cu ₂ O, and Cu ₂ O ₃ .

With this configuration, the following actions can be obtained in addition to the actions of the first to fifth aspects.

(1) Cu oxide is CuO, Cu ₂ O,
Since it is at least one selected from Cu ₂ O _3, it is possible to obtain an exhaust gas purifying catalyst having a high catalytic activity when burning particulates.

An exhaust gas purifying catalyst according to a seventh aspect of the present invention is the exhaust gas purifying catalyst according to the first to sixth aspects, wherein the transition metal oxide contains a composite metal oxide containing Cu and V.

With this structure, the following actions are obtained in addition to the actions of the first to sixth aspects.

(1) Since the transition metal oxide contains a composite metal oxide composed of Cu and V, particulates can be efficiently burned and removed, and the catalytic activity can be enhanced.

(2) Particulates can be removed by an oxidation reaction at a predetermined exhaust gas temperature.

The exhaust gas purifying catalyst according to claim 8 of the present invention is the exhaust gas purifying catalyst according to any one of claims 1 to 7, wherein the transition metal oxide is Cu ₅
It has a structure containing at least one mixed metal oxide selected from V ₂ O ₁₀ , CuV ₂ O ₆ , and Cu ₃ V ₂ O ₈ .

With this structure, the following actions are obtained in addition to the actions of the first to seventh aspects.

(1) The composite metal oxide is Cu ₅ V ₂ O ₁₀ , C
Since it is at least one selected from uV ₂ O ₆ and Cu ₃ V ₂ O _8, it is possible to obtain an exhaust gas purifying catalyst having higher catalytic activity when burning particulates.

An exhaust gas purifying catalyst according to a ninth aspect of the present invention is the exhaust gas purifying catalyst according to the first to eighth aspects, wherein the alkali metal sulfate contains cesium sulfate.

With this structure, the following actions are obtained in addition to the actions of the first to eighth aspects.

(1) Since the alkali metal sulfate contains cesium sulfate, the catalytic activity can be enhanced and the particulates can be burned efficiently, and the exhaust gas purification ability is extremely excellent.

An exhaust gas purifying catalyst according to a tenth aspect of the present invention is the catalyst according to any one of the first to ninth aspects, wherein the alkali metal sulfate contains a mixture of cesium sulfate and potassium sulfate.

With this configuration, the following actions can be obtained in addition to the actions of the first to ninth aspects.

(1) Since the alkali metal sulfate contains a mixture of cesium sulfate and potassium sulfate, it is possible to obtain an exhaust gas purifying catalyst having an extremely high catalytic activity when burning particulates.

The exhaust gas purifying catalyst according to claim 11 of the present invention is the exhaust heat purifying catalyst according to any one of claims 1 to 10, wherein the heat-resistant inorganic oxide is Ta ₂ O ₅ , Nb ₂ O ₅ , WO ₃ , SnO ₂ , SiO ₂ , Ti
It has a structure containing at least one inorganic oxide selected from O ₂ , Al ₂ O ₃ and ZrO ₂ .

With this structure, the following actions can be obtained in addition to the actions of the first to tenth aspects.

(1) As a carrier for supporting a transition metal oxide, Ta ₂ O ₅ , Nb ₂ O ₅ , WO ₃ , SnO ₂ , Si
Since it contains at least one inorganic oxide selected from O ₂ , TiO ₂ , Al ₂ O ₃ and ZrO ₂ , the surface area of the transition metal oxide catalyst becomes large, and as a result, the contact with particulates increases. Therefore, the oxidation performance of particulates can be exhibited most efficiently and stably.

An exhaust gas purifying catalyst according to a twelfth aspect of the present invention has a constitution according to any one of the first to eleventh aspects, in which the heat-resistant inorganic oxide is a powder having a particle size in the range of 0.1 μm to 1000 μm. ing.

With this structure, the following actions are obtained in addition to the actions of the first to eleventh aspects.

(1) As a carrier for supporting an oxide of a transition metal, a heat-resistant inorganic oxide has a particle size of 0.1 μm to 1000 μm.
Since the powder is in the range of μm, the number of contact points between the catalyst and the particulates is increased, so that the oxidation performance of the particulates can be most efficiently and stably exhibited.

The exhaust gas purifying material according to claim 13 of the present invention comprises a three-dimensional structure having heat resistance, and an exhaust gas purifying catalyst layer according to claim 1 formed on the three-dimensional structure. It has a configuration including.

With this configuration, in addition to the function of claim 1,
The following effects are obtained.

(1) By providing a transition metal oxide catalyst, a catalyst supporting a noble metal catalyst, and an alkali metal sulfate catalyst individually on the surface of a heat-resistant inorganic oxide, The reaction between the three-dimensional structure and the catalyst component can be suppressed, the catalytic activity can be enhanced, and deterioration of the catalyst can be prevented, resulting in excellent durability.

(2) By allowing each catalyst having a different function to exist separately, the reaction between the heat-resistant three-dimensional structure and the catalyst component can be suppressed, and a highly active exhaust gas purifying material can be obtained.

The exhaust gas purifying material according to claim 14 of the present invention comprises a three-dimensional structure having heat resistance, and an exhaust gas purifying catalyst layer according to claim 2 formed on the three-dimensional structure. , Is provided.

With this configuration, in addition to the function of claim 2,
The following effects are obtained.

(1) By providing a transition metal oxide catalyst, a catalyst supporting a noble metal catalyst, and an alkali metal sulfate catalyst individually on the surface of a heat-resistant inorganic oxide, The reaction between the three-dimensional structure and the catalyst component can be suppressed, the catalytic activity can be enhanced, and deterioration of the catalyst can be prevented, resulting in excellent durability.

(2) By allowing each catalyst having a different function to exist separately, the reaction between the heat-resistant three-dimensional structure and the catalyst component can be suppressed, and a highly active exhaust gas purification material can be obtained.

Here, as the heat resistant three-dimensional structure, a material such as metal or ceramic is used.

The exhaust gas purifying material according to claim 15 of the present invention comprises a three-dimensional structure having heat resistance, and an exhaust gas purifying catalyst layer according to claim 3 formed on the three-dimensional structure. , Is provided.

With this configuration, in addition to the function of claim 3,
The following effects are obtained.

(1) By providing a transition metal oxide catalyst, a catalyst supporting a noble metal catalyst, and an alkali metal sulfate catalyst individually on the surface of a heat-resistant inorganic oxide, The reaction between the three-dimensional structure and the catalyst component can be suppressed, the catalytic activity can be enhanced, and deterioration of the catalyst can be prevented, resulting in excellent durability.

(2) The presence of the catalysts having different functions separately suppresses the reaction between the heat-resistant three-dimensional structure and the catalyst component, and a highly active exhaust gas purification material can be obtained.

The method of forming the exhaust gas purifying catalyst according to claim 3 on the three-dimensional structure having heat resistance is not particularly limited, and any method can be used. For example, an impregnation method or a wash coat. There are methods such as methods.

An exhaust gas purifying material according to a sixteenth aspect of the present invention has the structure according to the thirteenth to fifteenth aspects, wherein the noble metal contains Pt.

With this structure, the following actions are obtained in addition to the actions of the thirteenth to fifteenth aspects.

(1) Since the noble metal contains Pt, S other than the carbon component in the particulates by the noble metal catalyst is used.
The OF component and the like can be burned and purified most efficiently and stably, and the exhaust gas purification capability is extremely excellent.

The exhaust gas purifying material according to claim 17 of the present invention is the exhaust gas purifying material according to any one of claims 13 to 16, wherein the transition metal oxide is C.
It has a structure containing at least one metal oxide selected from u, Mn, Co, V, Mo and W.

With this structure, the following actions are obtained in addition to the actions of the thirteenth to sixteenth aspects.

(1) The transition metal oxide is Cu, Mn, or C
Since it contains at least one metal oxide selected from o, V, Mo and W, it is possible to obtain an exhaust gas purifying material having a high catalytic activity when burning particulates.

The exhaust gas purifying material according to claim 18 of the present invention is the exhaust gas purifying material according to any one of claims 13 to 17, wherein the transition metal oxide is C.
at least 1 selected from uO, Cu ₂ O, and Cu ₂ O ₃
It has a structure containing a Cu oxide of a seed.

With this structure, the following actions are obtained in addition to the actions of the thirteenth to seventeenth aspects.

(1) The oxide of the transition metal is CuO, Cu ₂
Since it is at least one selected from O and Cu ₂ O _3, it is possible to obtain an exhaust gas purifying material having a high catalytic activity when burning particulates.

The exhaust gas purifying material according to claim 19 of the present invention is the exhaust gas purifying material according to any one of claims 13 to 18, wherein the transition metal oxide is C.
It has a structure containing a composite metal oxide composed of u and V.

With this structure, the following actions are obtained in addition to the actions of the thirteenth to eighteenth aspects.

(1) Since the transition metal oxide contains a composite metal oxide composed of Cu and V, it is possible to obtain an exhaust gas purifying material having a high catalytic activity when burning particulates.

The exhaust gas purifying material according to claim 20 of the present invention is the exhaust gas purifying material according to any one of claims 13 to 19, wherein the transition metal oxide is C.
It has a structure containing at least one mixed metal oxide selected from u ₅ V ₂ O ₁₀ , CuV ₂ O ₆ , and Cu ₃ V ₂ O ₈ .

With this structure, the following actions can be obtained in addition to the actions of the thirteenth to nineteenth aspects.

(1) The composite metal oxide is Cu ₅ V ₂ O ₁₀ , C
Since it is at least one selected from uV ₂ O ₆ and Cu ₃ V ₂ O _8, it is possible to obtain an exhaust gas purifying material having higher catalytic activity when burning particulates.

The exhaust gas purifying material according to a twenty-first aspect of the present invention has the structure according to the thirteenth to twentieth aspects, in which the alkali metal sulfate contains cesium sulfate.

With this structure, the following actions are obtained in addition to the actions of the thirteenth to twentieth aspects.

(1) Since the alkali metal sulphate contains cesium sulphate, the catalytic activity can be increased and the particulates can be burned efficiently and the exhaust gas purification ability is extremely excellent.

An exhaust gas purifying material according to a twenty-second aspect of the present invention is the exhaust gas purifying material according to the thirteenth to twenty-first aspects, wherein the alkali metal sulfate contains a mixture of cesium sulfate and potassium sulfate.

With this structure, the following actions are obtained in addition to the actions of the thirteenth to twenty-first aspects.

(1) Since the alkali metal sulphate contains a mixture of cesium sulphate and potassium sulphate, it is possible to obtain an exhaust gas purifying material having an extremely high catalytic activity when burning particulates.

The exhaust gas purifying material according to claim 23 of the present invention is the exhaust gas purifying material as claimed in claims 13 to 22, wherein the heat-resistant inorganic oxide is Ta ₂ O ₅ , Nb ₂ O ₅ , WO ₃ , SnO ₂ , SiO ₂ , Ti
It has a structure containing at least one inorganic oxide selected from O ₂ , Al ₂ O ₃ and ZrO ₂ .

With this configuration, the following actions can be obtained in addition to the actions of the thirteenth to twenty-second aspects.

(1) As a carrier for supporting a transition metal oxide, Ta ₂ O ₅ , Nb ₂ O ₅ , WO ₃ , SnO ₂ , Si
Since it contains at least one inorganic oxide selected from O ₂ , TiO ₂ , Al ₂ O ₃ and ZrO ₂ , the surface area of the transition metal oxide catalyst becomes large, and as a result, the contact with particulates increases. Therefore, the oxidation performance of particulates can be exhibited most efficiently and stably.

An exhaust gas purifying material according to a twenty-fourth aspect of the present invention is the exhaust gas purifying material according to the thirteenth to twenty-fourth aspects, wherein the heat-resistant three-dimensional structure is a wall-through type honeycomb filter, or a flow-through type foam or metal. It has a configuration that is a filter.

With this structure, the following actions can be obtained in addition to the actions of the thirteenth to twenty-fourth aspects.

(1) Since the tertiary structure having heat resistance is formed of a wall-through type honeycomb filter, a flow-through type foam or a metal filter, approximately 100% of the particulate component is used as a filter. It can be collected and the collection efficiency can be maximized.

(2) Since the three-dimensional structure is formed of the wall-through type honeycomb filter, the flow-through type foam or the metal filter, the contact area between the exhaust gas purifying catalyst and the particulates increases,
The particulates can be efficiently burned and removed,
It is possible to obtain an exhaust gas purifying material having extremely excellent exhaust gas purifying ability.

Each component of the exhaust gas purifying catalyst and the exhaust gas purifying material in the embodiment of the present invention will be described.

First, the heat-resistant inorganic oxide as a carrier will be described. As the heat-resistant inorganic oxide that supports a transition metal oxide and a noble metal, Ta is used.
₂ O ₅ , Nb ₂ O ₅ , WO ₃ , SnO ₂ , SiO ₂ , TiO ₂ ,
At least one inorganic oxide selected from Al ₂ O ₃ and ZrO ₂ can be used. In addition, you may use 2 or more types. Then, the oxide of the transition metal and the catalyst component of the noble metal are supported on the surface of the inorganic oxide, the surface area of the catalyst component increases, the chances of contact with PM increase, and the purification efficiency improves. Furthermore, the required amount of the catalyst can be reduced, and the cost can be reduced.

Next, the transition metal oxide catalyst will be described. First, as transition metals, Cu, Mn, Co, V,
Mo, W and the like can be mentioned, and one or more of these oxides can be used.

Specific examples of these transition metal oxides include CuO, V ₂ O ₅ , CoO ₃ , MnO ₂ , MoO ₃ ,
WO _{3 and the} like can be mentioned, and one or more of these can be used.

Particularly, Cu oxide is preferable, and as the Cu oxide, at least one selected from CuO, Cu ₂ O and Cu ₂ O ₃ can be used.

Further, the complex oxide is preferably a complex oxide composed of Cu and V, such as Cu ₅ V ₂ O ₁₀ , CuV ₂ O ₆ and Cu.
_At least one selected from ₃ V ₂ O ₈ can be used. Other composite oxides include CuMoO ₄ .

These transition metal oxides can efficiently remove PM by burning and enhance the catalytic activity. Further, by using the composite oxide composed of Cu and V, PM can be removed at a temperature close to the exhaust gas temperature.

Next, the noble metal will be described. Examples of the noble metal include Pt, Pd, Rh, Ru and the like, and one or more of these can be used. Then, the noble metal can reduce harmful components such as carbon monoxide, nitrogen oxides, and hydrocarbons that coexist with PM in the exhaust gas. Furthermore, by reacting with hydrocarbons and carbon monoxide in the exhaust gas from a low temperature, the exhaust gas temperature rises, and the catalytic activity of the transition metal oxide catalyst for PM can be improved. Among these precious metals, Pt is PM
It is particularly preferable because, for example, the SOF component other than the carbon component in 2) can be burned and purified very efficiently.

In addition, as the inorganic oxide, titania (TiO 2
₂ ) using platinum (Pt) as a noble metal and a complex oxide of copper (Cu) and vanadium (V) as a complex oxide of a transition metal, respectively, and a precious metal catalyst and an oxide of the transition metal. The combination with a catalyst has extremely high catalytic activity and is particularly preferable.

Here, the oxide of the transition metal and the noble metal carried on the surface of the inorganic oxide may be in a continuous layer state or in a discontinuous striped state on the surface of the inorganic oxide. Is also good. Furthermore, the oxide of the transition metal and the noble metal may be dispersed. That is, in the present invention, the transition metal oxide catalyst layer and the noble metal layer include a discontinuous striped state and a dispersed state.

Examples of the alkali metal salt include lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and cesium (Cs), and one or more of these alkali metals can be used in sulfuric acid. It is preferable to use a salt.

Specific examples of the alkali metal sulfates include lithium sulfate, sodium sulfate, potassium sulfate, rubidium sulfate and cesium sulfate, which contain cesium sulfate alone or a mixture of cesium sulfate and potassium sulfate. Is particularly preferable. By using the alkali metal sulfate, it is possible to prevent the catalyst component from being deteriorated by the sulfur content in the exhaust gas, and it is possible to maximize the catalytic activity for PM.

As the heat-resistant three-dimensional structure carrying the above exhaust gas purifying catalyst, a material such as metal or ceramic is used.

As the metal, it is possible to use metals such as iron, copper, nickel and chromium alone or alloys in which two or more metals are combined.

As the material of the ceramic, cordierite, aluminum titanate, mullite, α-alumina, zirconia, titania, silicon carbide, silica, silica-alumina, alumina-zirconia or the like can be used.

As the heat-resistant three-dimensional structure for forming the exhaust gas purifying catalyst, a wall-through type ceramic honeycomb, a ceramic foam, a wall-through type metal honeycomb, a metal foam, a metal mesh, or the like is used. A through type ceramic honeycomb is preferably used.

A wall-through type honeycomb filter or a flow-through type foam or metal filter is preferable.

Here, the material of the honeycomb filter is
Although not particularly limited, metals, ceramics, etc. are used.

The foam may have any shape such as a foam type filter having continuous pores in the three-dimensional direction.

The material of the foam is not particularly limited, and may be metal, ceramic or the like, but cordierite ceramic foam is preferably used.

The expansion ratio of the foam is preferably from 5 to 50 pores / square inch, more preferably 1
0 to 30 pieces / square inch.

The present invention is applicable not only to exhaust gas from automobile engines, but also to engines for transport engines such as cultivators, ships and trains.
It can be used for removing particulates in industrial engines, combustion furnaces, boilers and the like.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0135]

EXAMPLE A more specific example will be described below.

(Example 1) Titania powder (manufactured by Ishihara Sangyo,
MC-90) 1000 g, copper sulfate pentahydrate (made by Wako Pure Chemical Industries) 350 g as copper salt, vanadium oxide sulfate (manufactured by Wako Pure Chemical Industries Ltd.) 95 g as vanadium salt, and tetramine dichloroplatinum (soedagawa) as platinum salt. (Chemical) 36 g and 3300 g of purified water and sufficiently stirred, dried under reduced pressure by a cold evaporator, and the obtained powder is fired at 900 ° C. for 5 hours in an electric furnace to form a platinum-copper-vanadium composite. A powder in which oxide (Cu ₅ V ₂ O ₁₀ ) was supported on titania was obtained.

Thus obtained platinum and 10 g of a powder in which copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) as a transition metal was supported on titania, and reagent 1 of cesium sulfate.
0 g was mixed in a powder state in an agate mortar to obtain a powder catalyst containing cesium sulfate and a powder in which platinum and a copper-vanadium complex oxide (Cu ₅ V ₂ O ₁₀ ) were supported on titania.

(Example 2) Titania powder (manufactured by Ishihara Sangyo,
MC-90) 1000 g, copper sulfate pentahydrate (made by Wako Pure Chemical Industries) 350 g as a salt of copper, and vanadium oxide sulfate (made by Wako Pure Chemical Industries) 95 g as a salt of vanadium purified water 33
After being added to 00 g and sufficiently stirred, it was dried under reduced pressure with a cold evaporator, and the obtained powder was heated in an electric furnace to 900
Baking at 5 ° C for 5 hours gives a copper-vanadium composite oxide (C
A powder in which u ₅ V ₂ O ₁₀ ) was supported on titania was obtained.

As a transition metal thus obtained, 580 g of a powder of copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) supported on titania and 18 g of tetramine dichloroplatinum (manufactured by Soekawa Chemical Co., Ltd.) were purified. After adding to 1600 g of water and stirring sufficiently, it was dried under reduced pressure with a cold evaporator, and the obtained powder was baked in an electric furnace at 600 ° C. for 5 hours to obtain platinum and copper-vanadium composite oxide (Cu ₅ V
A powder in which ₂ O ₁₀ ) was supported on titania was obtained.

10 g of the powder thus obtained, on which platinum and a copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) were supported on titania, and 10 g of a cesium sulfate reagent, were placed in a powder state in an agate mortar. By mixing, platinum and a copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) were obtained as a powder catalyst containing a powder in which titania was supported and cesium sulfate.

(Comparative Example 1) Titania powder (manufactured by Ishihara Sangyo,
MC-90) 1000 g, copper sulfate pentahydrate (made by Wako Pure Chemical Industries) 350 g as a salt of copper, and vanadium oxide sulfate (made by Wako Pure Chemical Industries) 95 g as a salt of vanadium purified water 33
After being added to 00 g and sufficiently stirred, it was dried under reduced pressure with a cold evaporator, and the obtained powder was heated in an electric furnace to 900
Firing was performed at 5 ° C for 5 hours to obtain a powder in which copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) as a transition metal was supported on titania.

Also, titania powder (manufactured by Ishihara Sangyo, MC-
90 g), and tetramine dichloroplatinum (made by Soegawa Chemical Co., Ltd.) as a salt of platinum (36 g) were added to purified water (3300 g) and sufficiently stirred, followed by vacuum drying with a cold evaporator, and the obtained powder in an electric furnace. Baking was performed at 600 ° C. for 5 hours to obtain a powder in which platinum was supported on titania.

10 g of the powder obtained by carrying out the copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) thus obtained on titania, and 10 g of the powder carrying platinum on titania,
10 g of a cesium sulfate reagent was mixed in a powder state in an agate mortar, and a powder of copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) supported on titania and a powder of platinum supported on titania and sulfuric acid were mixed. A powder catalyst containing cesium was obtained.

Evaluation Example 1 With respect to the powder catalysts obtained in Examples 1, 2 and Comparative Example 1, the following particulate burning experiment was conducted.

Powders of each powder catalyst and simulated particulates (carbon made by Nakarai) were mixed at a weight ratio of 1: 1 in a mortar, and the mixture was filled in a quartz glass reaction tube having an inner diameter of 12 mm. 5vol% oxygen and 50pp in the reaction tube
m ₂ SO ₂ and a test gas consisting of nitrogen gas containing 250 ppm of NO gas at a flow rate of 500 cc / min, while heating the inside of the reaction tube at a constant speed in a tubular electric furnace arranged on the outer periphery of the reaction tube. did. At this time, the concentration of carbon dioxide in the test gas was detected by a carbon dioxide sensor arranged on the exhaust gas side, and the temperature at which 5% of particulates burned (hereinafter abbreviated as 5% burning temperature). It was determined. The burning rate was calculated from the carbon amount (known amount) of the charged particulates and the generated CO + CO ₂ amount (measured value).
The 5% combustion temperature of each exhaust gas purifying catalyst in the above combustion test is shown in (Table 1).

[0146]

[Table 1]

As is clear from (Table 1), even when the same kind of catalyst composition is used, the exhaust gas obtained in Examples 1 and 2 as compared with the exhaust gas purification catalyst obtained in Comparative Example 1 as the exhaust gas purification catalyst. It was found that the purification catalyst can burn particulates at a lower temperature.

(Example 3) Cu as an oxide of a transition metal
_A powder catalyst was obtained in the same manner as in Example 1 except that CuO was used instead of ₅ V ₂ O ₁₀ .

(Example 4) Cu as an oxide of a transition metal
_A powder catalyst was obtained in the same manner as in Example 1 except that MnO ₂ was used instead of ₅ V ₂ O ₁₀ .

(Example 5) Cu as an oxide of a transition metal
_A powder catalyst was obtained in the same manner as in Example 1 except that CoO ₃ was used instead of ₅ V ₂ O ₁₀ .

(Example 6) Cu as an oxide of a transition metal
_A powder catalyst was obtained in the same manner as in Example 1 except that V ₂ O ₅ was used instead of ₅ V ₂ O ₁₀ .

(Example 7) Cu as an oxide of a transition metal
_A powder catalyst was obtained in the same manner as in Example 1 except that MoO ₃ was used instead of ₅ V ₂ O ₁₀ .

(Example 8) Cu as an oxide of a transition metal
_A powder catalyst was obtained in the same manner as in Example 1 except that WO ₃ was used instead of ₅ V ₂ O ₁₀ .

(Example 9) Cu as oxide of transition metal
_A powder catalyst was obtained in the same manner as in Example 1 except that Cu ₂ O was used instead of ₅ V ₂ O ₁₀ .

(Example 10) C as an oxide of a transition metal
Example 1 except that Cu ₂ O ₃ was used instead of u ₅ V ₂ O _10.
A powder catalyst was obtained in the same manner as in.

(Example 11) C as an oxide of a transition metal
A powder catalyst was obtained in the same manner as in Example 1 except that CuV ₂ O ₆ was used instead of u ₅ V ₂ O ₁₀ .

(Example 12) C as an oxide of a transition metal
A powder catalyst was obtained in the same manner as in Example 1 except that Cu ₃ V ₂ O ₈ was used instead of u ₅ V ₂ O ₁₀ .

(Comparative Example 2) Cu as an oxide of a transition metal
_A powder catalyst was obtained in the same manner as in Example 1 except that LaMnCoO ₃ was used instead of ₅ V ₂ O ₁₀ .

(Evaluation Example 2) With respect to the powder catalysts obtained in Examples 3 to 12 and Comparative Example 2, a particulate combustion experiment was conducted in the same manner as in Evaluation Example 1. The 5% combustion temperature of each exhaust gas-purifying catalyst in the combustion test is shown in (Table 2).

[0160]

[Table 2]

As is clear from Table 2, when the exhaust gas purifying catalysts having the same structure are used, the exhaust gas purifying catalysts carrying the compounds shown in Examples 3 to 12 as the metal oxide of the transition metal to be carried. However, it was found that the particulates could be burned at a lower temperature.

Example 13 Example 1 was repeated, except that potassium cesium sulfate and cesium sulfate were mixed at a weight ratio of 1: 1 instead of cesium sulfate as the alkali metal sulfate.
A powder catalyst was obtained in the same manner as in.

(Comparative Example 3) A powder catalyst was obtained in the same manner as in Example 1 except that calcium sulfate was used instead of cesium sulfate as the alkali metal sulfate.

(Evaluation Example 3) With respect to the powder catalysts obtained in Example 13 and Comparative Example 3, a particulate burning experiment was conducted in the same manner as in Evaluation Example 1. The 5% combustion temperature of each exhaust gas purifying catalyst in the combustion test is shown in (Table 3).

[0165]

[Table 3]

As is clear from (Table 3), when the exhaust gas purifying catalyst having the same structure was used, the exhaust gas purifying catalyst supporting the compound shown in Example 13 as the metal oxide of the transition metal to be supported was It was found that particulates could be burned at lower temperatures.

Example 14 A powder catalyst was obtained in the same manner as in Example 1 except that Ta ₂ O ₅ was used as the catalyst carrier instead of titania.

Example 15 A powder catalyst was obtained in the same manner as in Example 1 except that Nb ₂ O ₃ was used as the catalyst carrier instead of titania.

Example 16 A powder catalyst was obtained in the same manner as in Example 1 except that WO ₃ was used as the catalyst carrier instead of titania.

Example 17 A powder catalyst was obtained in the same manner as in Example 1 except that SnO ₂ was used as the catalyst carrier instead of titania.

Example 18 A powder catalyst was obtained in the same manner as in Example 1 except that SiO ₂ was used as the catalyst carrier instead of titania.

Example 19 A powder catalyst was obtained in the same manner as in Example 1 except that Al ₂ O ₃ was used as the catalyst carrier instead of titania.

Example 20 A powder catalyst was obtained in the same manner as in Example 1 except that ZrO ₂ was used instead of titania as the catalyst carrier.

(Comparative Example 4) A powder catalyst was obtained in the same manner as in Example 1 except that Fe ₂ O ₃ was used as the catalyst carrier instead of titania.

(Evaluation Example 4) The powder catalysts obtained in Examples 14 to 20 and Comparative Example 4 were subjected to a particulate combustion experiment in the same manner as in Evaluation Example 1. The 5% combustion temperature of each exhaust gas purifying catalyst in the combustion test is shown in (Table 4).

[0176]

[Table 4]

As is clear from (Table 4), when the exhaust gas purifying catalysts having the same structure are used, the exhaust gas purifying catalysts using the carriers shown in Examples 14 to 20 are used as the carriers to be used at low temperatures. It turns out that the curate can be burned.

(Example 21) 1000 g of titania powder (manufactured by Ishihara Sangyo, MC-90), 350 g of copper sulfate pentahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) as a salt of copper, and vanadium oxide sulfate (sum of vanadium) Kogaku Yakuhin Co., Ltd.) 95 g, and tetramine dichloroplatinum (made by Soekawa Chemical Co., Ltd.) 36 g as a platinum salt were added to 3300 g of purified water and sufficiently stirred, and then dried under reduced pressure by a cold evaporator, and the obtained powder was placed in an electric furnace. Baking was performed at 900 ° C. for 5 hours to obtain a powder in which platinum and a copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) were supported on titania.

8 g of the powder thus obtained, 0.6 g of Poriti (manufactured by Lion) as a dispersant, and purified water 2
00g and 100g of 2mm zirconia balls
It was put in a closed vessel of ml and dispersed for 2 hours with a slurry disperser (made by Red Devil) to obtain a slurry.

Next, a wall-flow type cordierite filter (5.66 inches made by NGK, 100 cells / inch) was used as a heat-resistant three-dimensional structure in 2 cells ×
It is cut into 5 cells × 15 mm, impregnated with the slurry solution obtained above, the excess slurry is removed with an air gun, and then heat treatment is performed at 600 ° C. for 5 hours in an electric furnace.

On the other hand, 60 g of cesium sulfate (manufactured by Soekawa Chemical)
Was added to 500 g of purified water and sufficiently stirred to obtain an aqueous solution containing cesium sulfate. The filter obtained above was impregnated with this aqueous solution, the excess solution was removed with an air gun, and then dried with a drier, and the filter was placed in an electric furnace at 60
An exhaust gas purification material was manufactured by heat treatment at 0 ° C. for 5 hours.

(Example 22) 1000 g of titania powder (manufactured by Ishihara Sangyo, MC-90), 350 g of copper sulfate pentahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) as a copper salt, and vanadium oxide sulfate (sum of vanadium salt) (Koujunyaku Co., Ltd.) (95 g) and purified water (3300 g) were thoroughly stirred and dried under reduced pressure with a cold evaporator.
Firing was carried out at 00 ° C. for 5 hours to obtain a powder in which copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) was supported on titania.

As a transition metal thus obtained, 580 g of a powder of copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) supported on titania and 18 g of tetramine dichloroplatinum (manufactured by Soekawa Chemical Co., Ltd.) were purified. After adding to 1600 g of water and stirring sufficiently, it was dried under reduced pressure with a cold evaporator, and the obtained powder was baked in an electric furnace at 600 ° C. for 5 hours to obtain platinum and copper-vanadium composite oxide (Cu ₅ V
A powder in which ₂ O ₁₀ ) was supported on titania was obtained.

8 g of the powder thus obtained, 0.6 g of Poriti (manufactured by Lion) as a dispersant, and purified water 2
00g and 100g of 2mm zirconia balls
It was put in a closed vessel of ml and dispersed for 2 hours with a slurry disperser (made by Red Devil) to obtain a slurry.

Next, a wall flow type cordierite filter (5.66 inches made by NGK, 100 cells / inch) was used as a heat-resistant three-dimensional structure for 2 cells ×
It is cut into 5 cells × 15 mm, impregnated with the slurry solution obtained above, the excess slurry is removed with an air gun, and then heat treatment is performed at 600 ° C. for 5 hours in an electric furnace.

On the other hand, 60 g of cesium sulfate (manufactured by Soekawa Chemical Co., Ltd.)
Was added to 500 g of purified water and sufficiently stirred to obtain an aqueous solution containing cesium sulfate. The filter obtained above was impregnated with this aqueous solution, the excess solution was removed with an air gun, and then dried with a drier, and the filter was placed in an electric furnace at 60
An exhaust gas purification material was manufactured by heat treatment at 0 ° C. for 5 hours.

(Comparative Example 5) Titania powder (manufactured by Ishihara Sangyo,
MC-90) 1000 g, copper sulfate pentahydrate (made by Wako Pure Chemical Industries) 350 g as a salt of copper, and vanadium oxide sulfate (made by Wako Pure Chemical Industries) 95 g as a salt of vanadium purified water 33
After being added to 00 g and sufficiently stirred, it was dried under reduced pressure with a cold evaporator, and the obtained powder was heated in an electric furnace to 900
Firing was performed at 5 ° C for 5 hours to obtain a powder in which copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) as a transition metal was supported on titania.

Also, titania powder (manufactured by Ishihara Sangyo, MC-
90) 1000 g and 36 g of tetramine dichloroplatinum (made by Soegawa Chemical Co., Ltd.) as a salt of platinum were added to 3300 g of purified water and sufficiently stirred, and then dried under reduced pressure with a cold evaporator, and the obtained powder was 600 in an electric furnace. Firing was performed at 5 ° C. for 5 hours to obtain a powder in which platinum was supported on titania.

4 g of a powder of the thus obtained copper-vanadium composite oxide (Cu ₅ V ₂ O ₁₀ ) supported on titania, 4 g of a powder of platinum supported on titania, and a dispersant were used. Polite (made by Lion) 0.6g and purified water 2
00g and 100g of 2mm zirconia balls
It was put in a closed vessel of ml and dispersed for 2 hours with a slurry disperser (made by Red Devil) to obtain a slurry.

Next, a wall flow type cordierite filter (5.66 inches made by NGK, 100 cells / inch) was used as a heat-resistant three-dimensional structure, and 2 cells ×
It is cut into 5 cells × 15 mm, impregnated with the slurry solution obtained above, the excess slurry is removed with an air gun, and then heat treatment is performed at 600 ° C. for 5 hours in an electric furnace.

On the other hand, 60 g of cesium sulfate (manufactured by Soekawa Chemical Co., Ltd.)
Was added to 500 g of purified water and sufficiently stirred to obtain an aqueous solution containing cesium sulfate. The filter obtained above was impregnated with this aqueous solution, the excess solution was removed with an air gun, and then dried with a drier, and the filter was placed in an electric furnace at 60
An exhaust gas purification material was manufactured by heat treatment at 0 ° C. for 5 hours.

(Evaluation Example 5) With respect to the exhaust gas purifying materials obtained in Examples 21 to 22 and Comparative Example 5, the following particulate burning experiment was conducted.

One of the exhaust gas purifying materials obtained in Examples 21 to 22 and Comparative Example 5 was made to carry powder of simulated particulates (carbon made by Nakarai) on the filter surface and made of quartz glass having an inner diameter of 12 mm. The reaction tube was filled.

5 vol% oxygen and 50 pp in the reaction tube
m ₂ SO ₂ and a test gas consisting of nitrogen gas containing 250 ppm of NO gas at a flow rate of 500 cc / min, while heating the inside of the reaction tube at a constant speed in a tubular electric furnace arranged on the outer periphery of the reaction tube. At this time, the carbon dioxide concentration in the test gas was detected by the carbon dioxide sensor provided at the position on the gas outflow side, and the temperature at which 5% of particulates burned (hereinafter referred to as 5% combustion temperature abbreviated). Yes.) The burning rate was calculated from the carbon amount (known amount) of the charged particulates and the generated CO + CO ₂ amount (measured value).
The 5% combustion temperature of each exhaust gas purification material in the above combustion test is shown in (Table 5).

[0195]

[Table 5]

As is clear from Table 5, the exhaust gas purifying materials obtained in Examples 21 to 22 are the exhaust gas purifying materials obtained in Comparative Example 5 even when the same kind of catalyst composition is used. It has been found that it is possible to burn particulates at lower temperatures.

(Example 23) C as an oxide of a transition metal
Example 21 except that CuO was used instead of u ₅ V ₂ O _10.
An exhaust gas purification material was obtained in the same manner as in.

(Example 24) C as an oxide of a transition metal
Example 2 except that MnO ₂ was used instead of u ₅ V ₂ O _10.
An exhaust gas purification material was obtained in the same manner as in 1.

Example 25 C as an oxide of a transition metal
Example 2 except that CoO ₃ was used instead of u ₅ V ₂ O _10.
An exhaust gas purification material was obtained in the same manner as in 1.

Example 26 C as an oxide of a transition metal
Example 21 except that V ₂ O ₅ was used instead of u ₅ V ₂ O _10.
An exhaust gas purification material was obtained in the same manner as in.

Example 27 C as an oxide of a transition metal
Example 2 except that MoO ₃ was used instead of u ₅ V ₂ O _10.
An exhaust gas purification material was obtained in the same manner as in 1.

Example 28 C as an oxide of a transition metal
Example 21 except that WO ₃ was used instead of u ₅ V ₂ O _10.
An exhaust gas purification material was obtained in the same manner as in.

Example 29 C as an oxide of a transition metal
Example 2 except that Cu ₂ O was used instead of u ₅ V ₂ O _10.
An exhaust gas purification material was obtained in the same manner as in 1.

(Example 30) C as an oxide of a transition metal
Example 2 except that Cu ₂ O ₃ was used instead of u ₅ V ₂ O _10.
An exhaust gas purification material was obtained in the same manner as in 1.

(Example 31) C as an oxide of a transition metal
An exhaust gas purifying material was obtained in the same manner as in Example 21, except that CuV ₂ O ₆ was used instead of u ₅ V ₂ O ₁₀ .

(Example 32) C as an oxide of a transition metal
An exhaust gas purifying material was obtained in the same manner as in Example 21, except that Cu ₃ V ₂ O ₈ was used instead of u ₅ V ₂ O ₁₀ .

(Comparative Example 6) Cu as an oxide of a transition metal
An exhaust gas purification material was obtained in the same manner as in Example 1 except that LaMnCoO ₃ was used instead of ₅ V ₂ O ₁₀ .

Evaluation Example 6 With respect to the exhaust gas purifying materials obtained in Examples 23 to 32 and Comparative Example 6, a particulate combustion test was conducted in the same manner as in Evaluation Example 5. The 5% combustion temperature of each exhaust gas purifying catalyst in the combustion test is shown in (Table 6).

[0209]

[Table 6]

As is clear from (Table 6), when the exhaust gas purifying catalysts having the same structure are used, the exhaust gas purifying materials using the oxides shown in Examples 23 to 32 as the transition metal oxides used are It was found that particulates could be burned at lower temperatures.

(Example 33) Example 2 was repeated except that potassium sulfate and cesium sulfate were mixed at a weight ratio of 1: 1 instead of cesium sulfate as the alkali metal sulfate.
An exhaust gas purification material was obtained in the same manner as in 1.

Comparative Example 7 An exhaust gas purifying material was obtained in the same manner as in Example 21 except that calcium sulfate was used as the alkali metal sulfate instead of cesium sulfate.

Evaluation Example 7 With respect to the exhaust gas purifying materials obtained in Example 33 and Comparative Example 7, a particulate combustion test was conducted in the same manner as in Evaluation Example 5. The 5% combustion temperature of each exhaust gas purifying catalyst in the combustion test is shown in (Table 7).

[0214]

[Table 7]

As is clear from (Table 7), when the exhaust gas purifying catalyst having the same structure was used, the exhaust gas purifying material carrying the compound shown in Example 33 as the alkali sulfate to be carried was used at a lower temperature. It turns out that the particulates can be burned.

Example 34 An exhaust gas purifying material was obtained in the same manner as in Example 21, except that Ta ₂ O ₅ was used as the catalyst carrier instead of titania.

Example 35 An exhaust gas purifying material was obtained in the same manner as in Example 21 except that Nb ₂ O ₃ was used as the catalyst carrier instead of titania.

(Example 36) An exhaust gas purifying material was obtained in the same manner as in Example 21 except that WO ₃ was used as the catalyst carrier instead of titania.

Example 37 An exhaust gas purifying material was obtained in the same manner as in Example 21 except that SnO ₂ was used as the catalyst carrier instead of titania.

Example 38 An exhaust gas purifying material was obtained in the same manner as in Example 21 except that SiO ₂ was used as the catalyst carrier instead of titania.

Example 39 An exhaust gas purifying material was obtained in the same manner as in Example 21 except that Al ₂ O ₃ was used as the catalyst carrier instead of titania.

Example 40 An exhaust gas purifying material was obtained in the same manner as in Example 21 except that ZrO ₂ was used as the catalyst carrier instead of titania.

Comparative Example 8 An exhaust gas purifying material was obtained in the same manner as in Example 21, except that Fe ₂ O ₃ was used as the catalyst carrier instead of titania.

(Evaluation Example 8) The powder catalysts obtained in Examples 34 to 40 and Comparative Example 8 were subjected to a particulate combustion experiment in the same manner as in Evaluation Example 5. The 5% combustion temperature of each exhaust gas purifying catalyst in the combustion test is shown in (Table 8).

[0225]

[Table 8]

As is clear from Table 8, when the exhaust gas purifying materials having the same structure are used, the exhaust gas purifying materials using the carriers shown in Examples 34 to 40 are used as the carrier to be used at low temperatures. It turns out that the curate can be burned.

[0227]

As described above, according to the exhaust gas catalyst of the present invention and the exhaust gas purifying material using the same, the particulates in the exhaust gas can be burned and removed at a low temperature close to that of the exhaust gas, and the high catalytic activity for burning the particulates. An exhaust gas purifying catalyst having the above and an exhaust gas purifying material using the same can be provided.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F01N 3/02 301 F01N 3/10 A 321 3/24 E 3/10 3/28 301G 3/24 301S 3 / 28 301 B01D 46/42 B 53/36 104B // B01D 46/42 ZAB (72) Inventor Masaaki Arita 1006 Daimon Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Nobuyuki Tokubuchi Kadoma, Osaka Prefecture 1006 City Kadoma Matsushita Electric Industrial Co., Ltd. (72) Inventor Yohta Hashimoto Kadoma City Osaka Prefecture 1006 Kadoma Matsushita Electric Industrial Co., Ltd. F-term (reference) BA00 BA01 BA15 BA19 GA06 GA19 GA20 GB01W GB01X GB02W GB04W GB05W GB06W GB10W GB10X GB16X HA08 HA14 4D048 AA14 AB01 BA03X BA06X BA07X BA08X BA10X B A14X BA21X BA23X BA24X BA26X BA27X BA28X BA30X BA35X BA36X BA37X BA39Y BA41X BA42X BA46X BB02 BB09 BB14 4D058 JA32 JB06 JB28 MA44 SA08 TA06 4G069 AA03 BA01A BA01B BA02A BA02B BA04A BA04B BA05A BA05B BA13A BA17 BB02A BB02B BB04A BB04B BB06A BB06B BB10A BB10B BC01A BC03A BC03B BC06A BC06B BC22A BC22B BC29A BC31A BC31B BC54A BC54B BC55A BC55B BC56A BC56B BC59A BC59B BC60A BC60B BC62A BC62B BC67A BC67B BC69A BC75A BC75B CA02 CA03 CA07 CA18 EA18 EA27 EB11 EB12Y EB14Y EC28

Claims (24)

[Claims] 1. A first catalyst having a heat-resistant inorganic oxide, a transition metal oxide catalyst layer and a noble metal layer supported on the surface of the inorganic oxide, and at least one alkali metal sulfate. An exhaust gas purifying catalyst, comprising: 2. An inorganic oxide having heat resistance, and a transition metal oxide catalyst first layer supported on the surface of the inorganic oxide,
A first catalyst having a noble metal catalyst second layer on the first layer of the transition metal oxide catalyst and a second catalyst having at least one alkali metal sulfate. Exhaust gas purification catalyst. 3. A first catalyst having a heat-resistant inorganic oxide, a transition metal oxide and a noble metal supported on the surface of the inorganic oxide, and a first catalyst having at least one alkali metal sulfate. 2. An exhaust gas purifying catalyst, which comprises: 4. The exhaust gas purifying catalyst according to claim 1, wherein the noble metal contains Pt. 5. The transition metal oxide is Cu, Mn, C.
The exhaust gas purifying catalyst according to any one of claims 1 to 4, which contains at least one metal oxide selected from o, V, Mo, and W. 6. The oxide of the transition metal is CuO, Cu
The exhaust gas purifying catalyst according to any one of claims 1 to 5, comprising at least one Cu oxide selected from ₂ O and Cu ₂ O ₃ . 7. The compound of claim 1, wherein the oxide of the transition metal contains a complex metal oxide composed of Cu and V.
6. The exhaust gas purifying catalyst according to any one of 6 above. 8. The transition metal oxide is Cu_FiveV₂O_Ten, C
uV₂O₆, Cu₃V₂O ₈At least one selected from
2. The composite metal oxide according to claim 1 is contained.
~ The exhaust gas purifying catalyst according to any one of 7 to 7. 9. The exhaust gas purification catalyst according to claim 1, wherein the sulfate of the alkali metal contains cesium sulfate. 10. The exhaust gas purifying catalyst according to any one of claims 1 to 9, wherein the alkali metal sulfate contains a mixture of cesium sulfate and potassium sulfate. 11. The heat-resistant inorganic oxide is Ta ₂ O ₅ , N.
b ₂ O ₅ , WO ₃ , SnO ₂ , SiO ₂ , TiO ₂ , Al
The exhaust gas purifying catalyst according to any one of claims 1 to 10, which contains at least one inorganic oxide selected from ₂ O ₃ and ZrO ₂ . 12. The heat-resistant inorganic oxide has a particle size of 0.1 μm.
The exhaust gas purifying catalyst according to any one of claims 1 to 11, which is a powder in the range of m to 1000 µm. 13. A three-dimensional structure having heat resistance, and
An exhaust gas purification material comprising: the exhaust gas purification catalyst layer according to claim 1 formed on a three-dimensional structure. 14. A three-dimensional structure having heat resistance, and
An exhaust gas purifying material, comprising: the exhaust gas purifying catalyst layer according to claim 2 formed on a three-dimensional structure. 15. A three-dimensional structure having heat resistance, and
An exhaust gas purifying material, comprising: the exhaust gas purifying catalyst layer according to claim 3 formed on a three-dimensional structure. 16. The exhaust gas purifying material according to claim 13, wherein the noble metal contains Pt. 17. The transition metal oxide is Cu, Mn, C.
The exhaust gas purification material according to any one of claims 13 to 16, which contains at least one metal oxide selected from o, V, Mo, and W. 18. The transition metal oxide is CuO, Cu ₂
O, the exhaust gas purifying material according to any one of claims 13 to 17, characterized in that it contains an oxide of at least one of Cu is selected from Cu ₂ O _3. 19. The compound of claim 1, wherein the transition metal oxide contains a composite metal oxide of Cu and V.
The exhaust gas purifying material according to any one of 3 to 18. 20. The transition metal oxide is Cu ₅ V ₂ O ₁₀ ,
At least 1 selected from CuV ₂ O ₆ and Cu ₃ V ₂ O ₈
The exhaust gas purifying material according to any one of claims 13 to 19, which contains one kind of a mixed metal oxide. 21. The exhaust gas purifying material according to claim 13, wherein the alkali metal sulfate contains cesium sulfate. 22. The exhaust gas purifying material as claimed in claim 13, wherein the alkali metal sulfate contains a mixture of cesium sulfate and potassium sulfate. 23. The heat-resistant inorganic oxide is Ta ₂ O ₅ , N.
b ₂ O ₅ , WO ₃ , SnO ₂ , SiO ₂ , TiO ₂ , Al
The exhaust gas purification material according to any one of claims 13 to 22, characterized in that it contains at least one inorganic oxide selected from ₂ O ₃ and ZrO ₂ . 24. The heat-resistant three-dimensional structure is a wall-through type honeycomb filter, or a flow-through type foam or metal filter, according to any one of claims 13 to 23. Exhaust gas purification material described.