JP7295616B2 - Catalyst structure for volatile organic substances, method for producing the same, and device for removing volatile organic substances - Google Patents

Description

TECHNICAL FIELD The present invention relates to a volatile organic substance catalyst structure comprising a carrier having a porous structure and a volatile organic substance catalyst, a method for producing the same, and a volatile organic substance removing device.

Demand for air purification is increasing with the recent heightening of environmental awareness, and removal of volatile organic substances (hereinafter sometimes referred to as "VOC") is required. VOCs include, for example, toluene, benzene, chlorofluorocarbons, dichloromethane, etc. These are widely used because they are important substances as solvents and fuels. However, when VOCs are released into the environment, they cause health hazards such as pollution.

Therefore, the removal of VOCs by a catalyst has been studied, and for example, the removal of VOCs by an oxidation reaction has been studied. As the catalyst, a Pt-based catalyst is used from the viewpoint of high catalytic activity and stability. On the other hand, since Pt-based catalysts are expensive, the use of non-noble metal-based catalysts instead of Pt-based catalysts is also being investigated. However, non-precious metal catalysts can reduce the price, but the reaction temperature is higher than that of Pt catalysts.

Non-Patent Document 1 reports many catalyst systems in which Pt is supported on a carrier and exhibits excellent activity.

Industrial Materials January 2017 Vol. 65 No. 1 p. 71-74

However, in the conventional catalyst structure as described above, the catalyst particles are supported on the surface or near the surface of the carrier. inside the catalyst particles, and agglomeration (sintering) of the catalyst particles tends to occur. Agglomeration of the catalyst particles reduces the effective surface area of the catalyst, lowering the catalytic activity and shortening the life of the catalyst. Furthermore, aggregation of catalyst particles makes it difficult to remove catalyst poisons, which are compounds containing N, S, etc. derived from VOCs, and the catalytic function is likely to be deactivated.

An object of the present invention is to suppress a decrease in catalytic activity, facilitate the removal of catalyst poisons to prevent deactivation of the catalytic function, and prevent leakage of the catalyst from the catalyst structure. An object of the present invention is to provide a catalyst structure, a manufacturing method thereof, and a volatile organic substance removing apparatus.

As a result of intensive studies to achieve the above object, the present inventors have found that a volatile organic substance oxidizing agent comprising a carrier having a porous structure composed of a zeolite-type compound and at least one metal inherent in the carrier and a catalyst, wherein the carrier has passages communicating with each other, and the volatile organic substance oxidation catalyst is present in at least the passages of the carrier, thereby increasing the catalytic activity of the volatile organic substance oxidation catalyst. The present inventors have found that it is possible to obtain a catalyst structure for volatile organic substances that can suppress the decrease and realize a longer life, and have completed the present invention based on such findings.

That is, the gist and configuration of the present invention are as follows.
[1] a carrier having a porous structure composed of a zeolite-type compound;
at least one metal volatile organic substance oxidation catalyst inherent in the carrier;
with
the carrier has passages that communicate with each other;
A catalyst structure for volatile organic substances, wherein the volatile organic substance oxidation catalyst is present in at least the passages of the carrier.
[2] The passage is defined by the framework structure of the zeolite-type compound, and any of the one-dimensional, two-dimensional, and three-dimensional pores, and the one-dimensional, two-dimensional, and three-dimensional pores. for volatile organic substances according to [1] above, characterized in that it has an enlarged diameter portion different from any of them, and the volatile organic substance oxidation catalyst is present at least in the enlarged diameter portion. catalyst structure.
[3] The volatile according to [2] above, wherein the enlarged diameter portion communicates with a plurality of holes constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole Catalytic structures for organic substances.
[4] The catalyst structure for volatile organic substances according to the above [2] or [3], wherein the volatile organic substance oxidation catalyst is metal fine particles.
[5] The catalyst for volatile organic substances according to [4] above, wherein the average particle size of the fine metal particles is larger than the average inner diameter of the passage and equal to or smaller than the inner diameter of the expanded diameter portion. Structure.
[6] The above [5], wherein the metal element (M) of the metal fine particles is contained in an amount of 0.5 to 2.5% by mass with respect to the catalyst structure for volatile organic substances. A catalyst structure for volatile organic substances according to .
[7] The catalyst structure for volatile organic substances according to any one of [4] to [6] above, wherein the metal fine particles have an average particle size of 0.08 nm to 30 nm.
[8] The catalyst structure for volatile organic substances according to [7] above, wherein the average particle diameter of the metal fine particles is 0.4 nm to 11.0 nm.
[9] The volatilization according to any one of [4] to [8] above, wherein the ratio of the average particle diameter of the metal fine particles to the average inner diameter of the passage is 0.05 to 300. catalytic structures for organic substances.
[10] The catalyst structure for volatile organic substances according to [9] above, wherein the ratio of the average particle size of the fine metal particles to the average inner diameter of the passage is 0.1 to 30.
[11] The catalyst structure for volatile organic substances according to [10] above, wherein the ratio of the average particle size of the fine metal particles to the average inner diameter of the passage is 1.4 to 3.6. .
[12] the passage has an average inner diameter of 0.1 nm to 1.5 nm;
The catalyst structure for volatile organic substances according to any one of [2] to [11] above, wherein the inner diameter of the enlarged diameter portion is 0.5 nm to 50 nm.
[13] The volatile material according to any one of [1] to [12] above, further comprising at least one other volatile organic substance oxidation catalyst held on the outer surface of the carrier. Catalytic structures for organic substances.
[14] The content of the at least one volatile organic substance oxidation catalyst inherent in the carrier is greater than the content of the at least one other volatile organic substance oxidation catalyst retained on the outer surface of the carrier. The catalyst structure for volatile organic substances according to [13] above, characterized in that:
[15] The catalyst structure for volatile organic substances according to any one of [1] to [14] above, wherein the zeolite-type compound is a silicate compound.
[16] A volatile organic substance removing device comprising the volatile organic substance catalyst structure according to any one of [1] to [15] above.
[17] A calcination step of calcining the precursor material (A) impregnated with a metal-containing solution for obtaining a carrier having a porous structure composed of a zeolite-type compound;
a hydrothermal treatment step of hydrothermally treating the precursor material (C) obtained by firing the precursor material (B);
a step of subjecting the hydrothermally treated precursor material (C) to a reduction treatment;
A method for producing a catalyst structure for volatile organic substances, characterized by comprising:
[18] The volatile according to [17] above, characterized in that 50 to 500% by mass of a nonionic surfactant is added to the precursor material (A) before the baking step. A method for producing a catalyst structure for organic substances.
[19] impregnating the precursor material (A) with the metal-containing solution by adding the metal-containing solution to the precursor material (A) in multiple portions before the firing step; A method for producing a catalyst structure for volatile organic substances according to the above [17] or [18].
[20] When the precursor material (A) is impregnated with the metal-containing solution before the firing step, the amount of the metal-containing solution added to the precursor material (A) is In terms of the ratio (atomic ratio Si/M) of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to (A), The method for producing a catalyst structure for volatile organic substances according to any one of [17] to [19] above, wherein the adjustment is made so as to be 10 to 1000.
[21] The method for producing a catalyst structure for volatile organic substances according to [17] above, wherein the precursor material (C) and a structure-directing agent are mixed in the hydrothermal treatment step.
[22] The method for producing a catalyst structure for volatile organic substances according to [17] above, wherein the hydrothermal treatment step is performed in a basic atmosphere.

According to the present invention, it is possible to suppress a decrease in catalytic activity, facilitate removal of catalyst poisons to prevent deactivation of the catalytic function, and prevent leakage of the catalyst from the catalyst structure. A catalyst structure, a manufacturing method thereof, and a volatile organic substance removing device can be provided.

1A and 1B schematically show the internal structure of a catalyst structure for volatile organic substances according to an embodiment of the present invention. FIG. ), and FIG. 1(b) is a partially enlarged sectional view. FIG. 2 is a partially enlarged cross-sectional view for explaining an example of the function of the catalyst structure for volatile organic substances in FIG. 1, FIG. 2(a) explaining the sieve function, and FIG. It is a figure to do. FIG. 3 is a flow chart showing an example of a method for manufacturing the catalyst structure for volatile organic substances of FIG. FIG. 4 is a schematic diagram showing a modification of the volatile organic substance catalyst structure of FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Structure of catalyst structure for volatile organic substances]
1A and 1B are diagrams schematically showing the configuration of a catalyst structure for volatile organic substances according to an embodiment of the present invention. is a partially enlarged cross-sectional view. Note that the volatile organic substance catalyst structure in FIG. 1 shows an example thereof, and the shape, dimensions, etc. of each component according to the present invention are not limited to those in FIG.

As shown in FIG. 1( a ), the volatile organic substance catalyst structure 1 includes a carrier 10 having a porous structure made of a zeolite-type compound and at least one volatile and metal fine particles 20 that are an organic substance oxidation catalyst material. The volatile organic matter oxidation catalyst material functions as a volatile organic matter removal catalyst by oxidizing the volatile organic matter.

In the volatile organic substance catalyst structure 1, the plurality of metal fine particles 20, 20, . . . Details of the metal fine particles will be described later.

The carrier 10 has a porous structure, and as shown in FIG. 1(b), preferably has a plurality of holes 11a, 11a, . Here, the metal fine particles 20 are present in at least the passages 11 of the carrier 10 and preferably held in at least the passages 11 of the carrier 10 .

With such a configuration, movement of the metal fine particles 20 within the carrier 10 is regulated, and aggregation of the metal fine particles 20, 20 is effectively prevented. As a result, it is possible to effectively suppress the decrease in the effective surface area of the metal fine particles 20, which are volatile organic substance oxidation catalyst substances, and the catalytic activity of the metal fine particles 20 is maintained over a long period of time. That is, according to the volatile organic substance catalyst structure 1, it is possible to suppress the deterioration of the catalytic activity due to the aggregation of the metal fine particles 20, which are the volatile organic substance oxidation catalyst substance. Life can be extended. In addition, by extending the life of the volatile organic substance catalyst structure 1, the replacement frequency of the volatile organic substance catalyst structure 1 can be reduced, and the disposal amount of the used volatile organic substance catalyst structure 1 can be greatly reduced. can be reduced to 2, and resource saving can be achieved.

Generally, when the catalyst structure 1 for volatile organic substances is used in a fluid containing VOC, it may receive an external force from the fluid. In this case, if the metal microparticles 20 are only held in an adhering state on the outer surface of the carrier 10, there is a problem that they tend to separate from the outer surface of the carrier 10 under the influence of the external force from the fluid. On the other hand, in the volatile organic substance catalyst structure 1, the metal fine particles 20 are present at least in the passages 11 of the carrier 10. Therefore, even if the metal fine particles 20 are affected by the external force of the fluid, the metal fine particles 20 are released from the carrier 10. Hard to leave. That is, when the volatile organic substance catalyst structure 1 is in a fluid, the fluid flows into the passage 11 from the holes 11a of the carrier 10, so the speed of the fluid flowing in the passage 11 is reduced by the flow resistance ( It is thought that the speed of the fluid flowing on the outer surface of the carrier 10 becomes slower due to the frictional force). Due to the influence of such channel resistance, the pressure that the metal microparticles 20 in the passage 11 receive from the fluid is lower than the pressure that the metal microparticles 20 receive from the fluid outside the carrier 10 . Therefore, separation of the metal fine particles 20 inherent in the carrier 11 can be effectively suppressed, and the catalytic activity of the metal fine particles 20 can be stably maintained for a long period of time. It is believed that the flow path resistance as described above increases as the passage 11 of the carrier 10 has a plurality of bends and branches and the inside of the carrier 10 has a more complicated three-dimensional three-dimensional structure. .

In addition, the passage 11 is defined by the framework structure of the zeolite-type compound, and any of the one-dimensional, two-dimensional, and three-dimensional pores, and the one-dimensional, two-dimensional, and three-dimensional pores It is preferable to have an enlarged diameter portion 12 different from any of them, and at this time, it is preferable that the metal fine particles 20 exist at least in the enlarged diameter portion 12 and are enclosed by at least the enlarged diameter portion 12 is more preferable. The one-dimensional pore here means a tunnel-shaped or cage-shaped pore that forms a one-dimensional channel, or a plurality of tunnel-shaped or cage-shaped pores that form a plurality of one-dimensional channels (a plurality of one-dimensional pores). channel). A two-dimensional pore refers to a two-dimensional channel in which a plurality of one-dimensional channels are two-dimensionally connected, and a three-dimensional pore refers to a three-dimensional channel in which a plurality of one-dimensional channels are three-dimensionally connected. Point. As a result, the movement of the metal fine particles 20 within the carrier 10 is further restricted, and separation of the metal fine particles 20 and agglomeration of the metal fine particles 20, 20 can be more effectively prevented. Inclusion refers to a state in which the metal fine particles 20 are included in the carrier 10 . At this time, the metal fine particles 20 and the carrier 10 do not necessarily have to be in direct contact with each other, and another substance (for example, a surfactant or the like) is interposed between the metal fine particles 20 and the carrier 10. Also, the metal microparticles 20 may indirectly exist on the carrier 10 .

Although FIG. 1B shows the case where the metal fine particles 20 are present in the diameter-enlarged portion 12 , it is not limited to this configuration, and a part of the metal fine-particles 20 is outside the diameter-enlarged portion 12 . It may exist in the passage 11 in a protruded state. Moreover, the fine metal particles 20 may be partially embedded in a portion of the passage 11 other than the enlarged diameter portion 12 (for example, an inner wall portion of the passage 11), or may be present by being fixed or the like.
Moreover, it is preferable that the diameter-enlarging portion 12 communicates with a plurality of holes 11a, 11a forming any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole. As a result, a passage different from the one-dimensional hole, the two-dimensional hole, or the three-dimensional hole is provided inside the carrier 10, so that the function of the metal fine particles 20 can be exhibited more effectively.

Further, the passage 11 is formed three-dimensionally inside the carrier 10 including a branched portion or a confluence, and the enlarged diameter portion 12 is preferably provided at the branched portion or the confluence of the passage 11. .

The average inner diameter D _F of the passages 11 formed in the carrier 10 is calculated from the average value of the short diameter and long diameter of the holes 11a constituting any one of the one-dimensional, two-dimensional and three-dimensional holes. It is 0.1 nm to 1.5 nm, preferably 0.5 nm to 0.8 nm. Further, the inner diameter D _E of the expanded diameter portion 12 is, for example, 0.5 nm to 50 nm, preferably 1.1 nm to 40 nm, more preferably 1.1 nm to 3.3 nm. The inner diameter D _E of the expanded diameter portion 12 depends, for example, on the pore diameter of the precursor material (A) described later and the average particle diameter D _C of the existing metal fine particles 20 . The inner diameter D _E of the expanded diameter portion 12 is a size in which the metal fine particles 20 can exist.

Carrier 10 is composed of a zeolite-type compound. Examples of zeolite-type compounds include zeolite (aluminosilicate), cation-exchanged zeolite, silicate compounds such as silicalite, zeolite-related compounds such as aluminoborates, aluminoarsenates, and germanates, and molybdenum phosphate. phosphate-based zeolite-like substances, and the like. Among them, the zeolite-type compound is preferably a silicate compound.

The skeleton structure of the zeolite type compound is FAU type (Y type or X type), MTW type, MFI type (ZSM-5), FER type (ferrierite), LTA type (A type), MWW type (MCM-22). , MOR type (mordenite), LTL type (L type), BEA type (beta type), etc., preferably MFI type, more preferably ZSM-5. A zeolite-type compound is formed with a plurality of pores having a pore size corresponding to each skeleton structure. be.

The metal fine particles 20, which are the volatile organic substance oxidation catalyst material, will be described in detail below.

The fine metal particles 20 may be primary particles _or may be secondary particles formed by agglomeration of primary particles _. and equal to or less than the inner diameter D _E of the enlarged diameter portion 12 (D _F <D _C ≦D _E ). Such fine metal particles 20 are present in the diameter-enlarged portion 12 in the passage 11 and are preferably enclosed, so that movement of the fine metal particles 20 within the carrier 10 is restricted. Therefore, even when the metal microparticles 20 receive an external force from the fluid, the movement of the metal microparticles 20 within the carrier 10 is suppressed, and the expanded diameter portions 12, 12, . . can be effectively prevented from coming into contact with each other.

In addition, the average particle diameter D _C of the metal fine particles 20 is preferably 0.08 nm to 30 nm, more preferably 0.08 nm or more and less than 25 nm, and even more preferably 0.4 nm to 11.0 nm, particularly preferably 0.8 nm to 2.7 nm. In addition, the ratio of the average particle diameter D _C of the metal fine particles 20 to the average inner diameter D _F of the passage 11 (D _C /D _F ) is preferably 0.05 to 300, more preferably 0.1 to 30. , more preferably 1.1 to 30, particularly preferably 1.4 to 3.6.
Further, when the volatile organic substance oxidation catalyst material 20 is metal fine particles, the metal element (M) of the metal fine particles is contained in an amount of 0.5 to 2.5% by mass with respect to the catalyst structure 1 for volatile organic substances. more preferably 0.5 to 1.5% by mass with respect to the catalyst structure 1 for volatile organic substances. For example, when the metal element (M) is Co, the content (% by mass) of the Co element is [(mass of Co element)/(mass of all elements in catalyst structure 1 for volatile organic substances)]× It is represented by 100.

The metal fine particles 20 may be composed of a metal that is not oxidized, and may be composed of, for example, a single metal, or a mixture of two or more metals. In this specification, the “metal” (as a material) that constitutes the metal fine particles refers to a single metal containing one type of metal element (M) and a metal alloy containing two or more types of metal elements (M). is a generic term for metals containing one or more metal elements.

Examples of such metals include platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), silver (Ag) and the like, and any one or more of the above may be used as a main component. is preferred.

Further, the ratio of silicon (Si) constituting the carrier 10 to the metal element (M) constituting the metal fine particles 20 (atomic ratio Si/M) is preferably 10 to 1000, more preferably 50 to 200. is more preferred. If the above ratio is more than 1000, the activity is low, and there is a possibility that the action as a volatile organic substance oxidation catalyst substance cannot be sufficiently obtained. On the other hand, if the ratio is less than 10, the ratio of the fine metal particles 20 becomes too large, and the strength of the carrier 10 tends to decrease. The metal fine particles 20 referred to here refer to fine particles that are present inside the carrier 10 and are preferably held or supported, and do not include metal fine particles adhering to the outer surface of the carrier 10 .

[Function of catalyst structure for volatile organic substances]
As described above, the catalyst structure 1 for volatile organic substances comprises a carrier 10 having a porous structure and at least one fine metal particle 20 present in the carrier. The catalyst structure 1 for volatile organic substances exhibits a catalytic ability corresponding to the catalytic activity of the metal fine particles 20 when the metal fine particles 20 contained in the carrier come into contact with the fluid. Specifically, the fluid coming into contact with the outer surface 10a of the volatile organic substance catalyst structure 1 flows into the inside of the carrier 10 through the holes 11a formed in the outer surface 10a, is guided into the passage 11, and is guided into the passage 11. , and exits the volatile organic substance catalyst structure 1 through another hole 11a. When the fluid comes into contact with the metal microparticles 20 present in the passageway 11 on the path along which the fluid moves through the passageway 11 , a catalytic reaction occurs according to the catalytic ability of the metal microparticles 20 . Further, the catalyst structure 1 for volatile organic substances has a molecular sieving ability due to the porous structure of the carrier.

First, the molecular sieving ability of the catalyst structure 1 for volatile organic substances will be described with reference to FIG. . As shown in FIG. 2( a ), VOCs (e.g., benzene, toluene, etc.) composed of molecules having a size equal to or smaller than the diameter of the holes 11 a , in other words, the inner diameter of the passage 11 flow into the carrier 10 . can do. On the other hand, the non-VOC components 15 having a size exceeding the pore diameter of the pores 11 a cannot flow into the carrier 10 . In this way, when the fluid contains multiple types of compounds, the reaction of the compounds that cannot flow into the carrier 10 is regulated, and the compounds that can flow into the carrier 10 can react.

Among the compounds produced in the carrier 10 by the reaction, only compounds composed of molecules having a size equal to or smaller than the pore diameter of the pores 11a can exit the carrier 10 through the pores 11a and are obtained as reaction products. On the other hand, compounds that cannot exit the carrier 10 through the pores 11a can be expelled from the carrier 10 by converting them into compounds composed of molecules having a size that allows them to exit the carrier 10. . Thus, by using the catalyst structure 1 for volatile organic substances, a specific reaction product can be selectively obtained.

In the volatile organic substance catalyst structure 1, as shown in FIG. When the average particle diameter D _C of the metal fine particles 20 is larger than the average inner diameter D _F of the passage 11 and smaller than the inner diameter D _E of the expanded diameter portion 12 (D _F <D _C <D _E ), the metal fine particles 20 and the enlarged diameter portion 12, a small passage 13 is formed. 2(b), the VOC-containing fluid that has flowed into the small passage 13 comes into contact with the fine metal particles 20. As shown in FIG. Since each metal fine particle 20 exists in the expanded diameter portion 12 , movement within the carrier 10 is restricted. This prevents aggregation of the metal fine particles 20 and 20 in the carrier 10 . As a result, a large contact area between the metal microparticles 20 and the fluid can be stably maintained.

Then, when the VOC that has flowed into the passage 11 comes into contact with the metal fine particles 20, the VOC is oxidized by an oxidative decomposition reaction caused by the metal fine particles 20. As shown in FIG. For example, when ruthenium contained in the metal fine particles 20 is used as a catalyst, VOCs are decomposed into carbon dioxide, water, and the like to be rendered harmless. By performing the oxidative decomposition treatment with the metal fine particles 20 in this way, the VOC can be rendered harmless. Moreover, a volatile organic substance removal device may be formed using the volatile organic substance catalyst structure 1 . By using the volatile organic substance catalyst structure 1 according to the above embodiment, it is possible to obtain a volatile organic substance removing device that exhibits the same effects as those described above.

[Method for producing catalyst structure for volatile organic substances]
FIG. 3 is a flow chart showing a method of manufacturing the catalyst structure 1 for volatile organic substances of FIG. An example of a method for producing a catalyst structure for volatile organic substances, in which the volatile organic substance oxidation catalyst material present in the carrier is metal fine particles, will be described below.

(Step S1: preparation process)
As shown in FIG. 3, first, a precursor material (A) for obtaining a carrier having a porous structure composed of a zeolite-type compound is prepared. The precursor material (A) is preferably a regular mesoporous material, and can be appropriately selected according to the type (composition) of the zeolite compound that constitutes the carrier of the catalyst structure for volatile organic substances.

Here, when the zeolite-type compound constituting the carrier of the catalyst structure for volatile organic substances is a silicate compound, the regular mesoporous material has pores with a pore diameter of 1 to 50 nm. It is preferably a compound consisting of a Si—O skeleton that has a uniform size and is regularly developed two-dimensionally or three-dimensionally. Such regular mesoporous materials can be obtained as various synthetic products depending on the synthesis conditions. 16, MCM-41 and the like, among which MCM-41 is preferred. The pore diameter of SBA-1 is 10 to 30 nm, the pore diameter of SBA-15 is 6 to 10 nm, the pore diameter of SBA-16 is 6 nm, the pore diameter of KIT-6 is 9 nm, and the pore diameter of FSM-16 is 3 nm. ˜5 nm, and the pore size of MCM-41 is 1-10 nm. Examples of such ordered mesoporous materials include mesoporous silica, mesoporous aluminosilicate, mesoporous metallosilicate, and the like.

Precursor material (A) may be either commercially available or synthetic. Synthesis of the precursor material (A) can be carried out by a known method for synthesizing ordered mesoporous materials. For example, a mixed solution containing raw materials containing constituent elements of the precursor material (A) and a templating agent for defining the structure of the precursor material (A) is prepared, and the pH is adjusted as necessary. , perform hydrothermal treatment (hydrothermal synthesis). After that, the precipitate (product) obtained by the hydrothermal treatment is recovered (for example, filtered), washed and dried as necessary, and further calcined to obtain a powdery ordered mesoporous material. A precursor material (A) is obtained. Here, as the solvent of the mixed solution, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used. The raw material is selected according to the type of carrier, and examples thereof include silica agents such as tetraethoxysilane (TEOS), fumed silica, and quartz sand. As the templating agent, various surfactants, block copolymers, etc. can be used, and it is preferable to select them according to the type of synthetic material of the regular mesoporous material. is preferably a surfactant such as hexadecyltrimethylammonium bromide. The hydrothermal treatment can be carried out, for example, in a closed vessel under conditions of 80 to 800° C., 5 hours to 240 hours, and 0 to 2000 kPa. The calcination treatment can be performed, for example, in the air at 350 to 850° C. for 2 to 30 hours.

(Step S2: impregnation step)
Next, the prepared precursor material (A) is impregnated with a metal-containing solution to obtain a precursor material (B).

The metal-containing solution may be any solution containing a metal component (for example, metal ion) corresponding to the metal element (M) constituting the metal fine particles of the catalyst structure for volatile organic substances. It can be prepared by dissolving a metal salt containing the element (M). Examples of such metal salts include metal salts such as chlorides, hydroxides, oxides, sulfates and nitrates, with nitrates being preferred. As the solvent, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used.

The method for impregnating the precursor material (A) with the metal-containing solution is not particularly limited. It is preferable to divide and add little by little each time. In addition, from the viewpoint of making it easier for the metal-containing solution to penetrate into the pores of the precursor material (A), a surfactant is added as an additive to the precursor material (A) in advance before adding the metal-containing solution. It is preferable to add. Such an additive has the function of coating the outer surface of the precursor material (A), suppresses the metal-containing solution added thereafter from adhering to the outer surface of the precursor material (A), It is believed that the contained solution is more likely to penetrate into the pores of the precursor material (A).

Examples of such additives include nonionic surfactants such as polyoxyethylene oleyl ether, polyoxyethylene alkyl ether and polyoxyethylene alkylphenyl ether. Since these surfactants have a large molecular size and cannot penetrate into the pores of the precursor material (A), they do not adhere to the inside of the pores and prevent the metal-containing solution from entering into the pores. not considered to be a hindrance. As a method for adding the nonionic surfactant, for example, it is preferable to add 50 to 500% by mass of the nonionic surfactant to the precursor material (A) before the baking step described later. If the amount of the nonionic surfactant added to the precursor material (A) is less than 50% by mass, the above suppressing action is difficult to manifest, and the nonionic surfactant is added to the precursor material (A) in an amount of 500% by mass. Adding more than % by mass is not preferable because the viscosity increases too much. Therefore, the amount of the nonionic surfactant added to the precursor material (A) is set within the above range.

In addition, the amount of the metal-containing solution added to the precursor material (A) is the amount of the metal element (M) contained in the metal-containing solution impregnated into the precursor material (A) (that is, the amount of the precursor material (B ) is preferably adjusted as appropriate in consideration of the amount of the metal element (M) to be incorporated in ). For example, before the firing step to be described later, the addition amount of the metal-containing solution added to the precursor material (A) is set to In terms of the ratio of silicon (Si) constituting the precursor material (A) (atomic ratio Si/M), it is preferably adjusted to be 10 to 1000, and adjusted to be 50 to 200. is more preferable. For example, if a surfactant is added as an additive to the precursor material (A) before adding the metal-containing solution to the precursor material (A), the addition of the metal-containing solution to the precursor material (A) By setting the amount to 50 to 200 in terms of the atomic ratio Si/M, the metal element (M) of the metal fine particles is 0.5 to 2.5 with respect to the catalyst structure 1 for volatile organic substances. It can be contained in mass %. In the state of the precursor material (B), the amount of the metal element (M) present inside the pores is the same under conditions such as the metal concentration of the metal-containing solution, the presence or absence of the above additives, and other conditions such as temperature and pressure. If so, it is roughly proportional to the amount of the metal-containing solution added to the precursor material (A). Further, the amount of the metal element (M) inherent in the precursor material (B) is in a proportional relationship with the amount of the metal element constituting the metal fine particles inherent in the carrier of the catalyst structure for volatile organic substances. Therefore, by controlling the addition amount of the metal-containing solution to be added to the precursor material (A) within the above range, the inside of the pores of the precursor material (A) can be sufficiently impregnated with the metal-containing solution. , the amount of metal microparticles incorporated in the carrier of the catalyst structure for volatile organic substances can be adjusted.

After impregnating the precursor material (A) with the metal-containing solution, a washing treatment may be performed as necessary. As the cleaning solution, water, an organic solvent such as alcohol, or a mixed solution thereof can be used. Moreover, it is preferable that the precursor material (A) is impregnated with the metal-containing solution, washed as necessary, and then dried. Drying treatments include natural drying for about one night and high-temperature drying at 150° C. or less. In addition, when the precursor material (A) is subjected to the firing treatment described later in a state in which a large amount of water contained in the metal-containing solution or the washing solution remains in the precursor material (A), regular mesopores of the precursor material (A) Sufficient drying is preferable because the skeleton structure of the substance may be destroyed.

(Step S3: Firing step)
Next, the precursor material (B) in which the metal-containing solution is impregnated in the precursor material (A) for obtaining a carrier having a porous structure composed of a zeolite-type compound is calcined to obtain a precursor material (C). get

The calcination treatment is preferably carried out, for example, in the air at 350 to 850° C. for 2 to 30 hours. By such a calcination treatment, the metal component impregnated in the pores of the ordered mesoporous material undergoes crystal growth to form fine metal particles in the pores.

(Step S4: hydrothermal treatment step)
Next, a mixed solution is prepared by mixing the precursor material (C) and a structure-directing agent, and the precursor material (C) obtained by baking the precursor material (B) is hydrothermally treated to obtain a volatile A catalyst structure for an organic material is obtained.

The structure-directing agent is a templating agent for defining the skeleton structure of the carrier of the catalyst structure for volatile organic substances, and for example, a surfactant can be used. The structure-directing agent is preferably selected according to the skeleton structure of the carrier of the catalyst structure for volatile organic substances. and other surfactants are suitable.

Mixing of the precursor material (C) and the structure-directing agent may be performed during the main hydrothermal treatment step or before the hydrothermal treatment step. The method for preparing the mixed solution is not particularly limited, and the precursor material (C), the structure-directing agent, and the solvent may be mixed at the same time, or the precursor material (C) and the structure-directing agent may be mixed together in the solvent. Each dispersion solution may be mixed after dispersing each of the agents into individual solutions. As the solvent, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used. Moreover, it is preferable that the mixed solution is adjusted in pH with an acid or a base before the hydrothermal treatment.

The hydrothermal treatment can be carried out by a known method, and is preferably carried out in a closed vessel under treatment conditions of 80 to 800° C., 5 hours to 240 hours, and 0 to 2000 kPa. Also, the hydrothermal treatment is preferably performed in a basic atmosphere. Although the reaction mechanism here is not necessarily clear, by performing hydrothermal treatment using the precursor material (C) as a raw material, the skeletal structure of the precursor material (C) as an ordered mesoporous substance gradually collapses. While the position of the metal fine particles inside the pores of the precursor material (C) is generally maintained, the action of the structure-directing agent creates a new skeleton structure (porous structure) as a support for the catalyst structure for volatile organic substances. ) is formed. The catalyst structure for a volatile organic substance thus obtained comprises a carrier having a porous structure and fine metal particles present in the carrier. At least a portion of the fine metal particles resides in the passages of the carrier.
In the present embodiment, in the hydrothermal treatment step, a mixed solution is prepared by mixing the precursor material (C) and the structure-directing agent, and the precursor material (C) is hydrothermally treated. Alternatively, the precursor material (C) may be hydrothermally treated without mixing the precursor material (C) and the structure-directing agent.

The precipitate (catalyst structure for volatile organic substances) obtained after the hydrothermal treatment is preferably recovered (for example, filtered) and then washed, dried and calcined as necessary. As the cleaning solution, water, an organic solvent such as alcohol, or a mixed solution thereof can be used. Drying treatments include natural drying for about one night and high-temperature drying at 150° C. or less. It should be noted that if the calcination treatment is carried out in a state in which a large amount of water remains in the precipitate, the skeleton structure as a carrier of the catalyst structure for volatile organic substances may be destroyed, so it is preferable to dry the precipitate sufficiently. Further, the calcination treatment can be performed, for example, in the air under the treatment conditions of 350 to 850° C. for 2 to 30 hours. By such a calcination treatment, the structure-directing agent adhering to the volatile organic substance catalyst structure is burned off. In addition, the catalyst structure for volatile organic substances can be used as it is without calcining the collected precipitate depending on the purpose of use. For example, if the environment in which the catalyst structure for volatile organic substances is used is a high-temperature environment with an oxidizing atmosphere, the structure-directing agent will be burned away by exposing it to the environment for a certain period of time, which is the same as in the case of calcination. is obtained, it is possible to use it as it is.

The manufacturing method described above is an example in which the metal element (M) contained in the metal-containing solution with which the precursor material (A) is impregnated is a metal species that is difficult to be oxidized (eg, noble metal).

When the metal element (M) contained in the metal-containing solution with which the precursor material (A) is impregnated is a metal species that is easily oxidized (e.g., Fe, Co, Cu, etc.), after the hydrothermal treatment step, It is preferable to subject the hydrothermally treated precursor material (C) to a reduction treatment. If the metal element (M) contained in the metal-containing solution is a metal species that is easily oxidized, the metal component will be oxidized by the heat treatment in the steps (steps S3 and S4) after the impregnation treatment (step S2). . Therefore, the carrier formed in the hydrothermal treatment step (step S4) contains the metal oxide fine particles. Therefore, in order to obtain a catalyst structure for a volatile organic substance in which metal fine particles are inherent in the carrier, after the above hydrothermal treatment, the collected precipitate is calcined and then reduced in an atmosphere of a reducing gas such as hydrogen gas. is desirable (step S5: reduction treatment step). By performing the reduction treatment, the metal oxide fine particles inherent in the carrier are reduced to form metal fine particles corresponding to the metal element (M) constituting the metal oxide fine particles. As a result, a catalyst structure for volatile organic substances is obtained in which the metal fine particles are contained in the carrier. Such a reduction treatment may be performed as necessary. For example, when the environment in which the catalyst structure for volatile organic substances is used is a reducing atmosphere, exposing it to the usage environment for a certain period of time Since the metal oxide fine particles are reduced, the same catalyst structure for volatile organic substances as in the case of the reduction treatment can be obtained, so that the carrier can be used as it is in a state in which the oxide fine particles are contained therein.

[Modified Example of Catalyst Structure 1 for Volatile Organic Substances]
FIG. 4 is a schematic diagram showing a modification of the volatile organic substance catalyst structure 1 of FIG.
Although the catalyst structure 1 for volatile organic substances in FIG. 1 is provided with the carrier 10 and the metal fine particles 20 contained in the carrier 10, it is not limited to this configuration. As shown, the volatile organics catalyst structure 2 may further comprise other metal particles 30 of volatile organics oxidation catalyst material retained on the outer surface 10a of the carrier 10 .

The other metal microparticles 30 are substances that exhibit one or more catalytic functions. The catalytic ability of the other fine metal particles 30 may be the same as or different from the catalytic ability of the fine metal particles 20 . Moreover, when both of the metal fine particles 20 and 30 are substances having the same catalytic ability, the material of the other metal fine particles 30 may be the same as or different from the material of the metal fine particles 20 . According to this configuration, the content of the volatile organic substance oxidation catalyst substance held in the volatile organic substance catalyst structure 2 can be increased, further promoting the catalytic activity of the volatile organic substance oxidation catalyst substance. be able to.

In this case, the content of the metal fine particles 20 inherent in the carrier 10 is preferably higher than the content of the other metal fine particles 30 retained on the outer surface 10a of the carrier 10 . As a result, the catalytic activity of the metal fine particles 20 held inside the carrier 10 becomes dominant, and the catalytic activity of the volatile organic substance oxidation catalyst substance is exhibited stably.

Although the catalyst structure for volatile organic substances according to the embodiments of the present invention has been described above, the present invention is not limited to the above embodiments, and various modifications and changes can be made based on the technical idea of the present invention. It is possible.

(Examples 1 to 384)
[Synthesis of precursor material (A)]
A mixed aqueous solution is prepared by mixing a silica agent (tetraethoxysilane (TEOS), manufactured by Wako Pure Chemical Industries, Ltd.) and a surfactant as a template agent, and the pH is adjusted as appropriate. Hydrothermal treatment was performed at 350° C. for 100 hours. After that, the produced precipitate is filtered off, washed with water and ethanol, and further calcined in the air at 600° C. for 24 hours to obtain the precursor material (A) having the types and pore sizes shown in Tables 1 to 8. Obtained. The following surfactants were used according to the type of the precursor material (A) (“type of precursor material (A): surfactant”).
・ MCM-41: hexadecyltrimethylammonium bromide (CTAB) (manufactured by Wako Pure Chemical Industries, Ltd.)
・ SBA-1: Pluronic P123 (manufactured by BASF)

[Production of precursor materials (B) and (C)]
Next, according to the metal element (M) constituting the metal fine particles of the types shown in Tables 1 to 8, a metal salt containing the metal element (M) is dissolved in water to prepare a metal-containing aqueous solution. bottom. The following metal salts were used according to the type of metal fine particles (“metal fine particles: metal salt”).
・ Pt: chloroplatinic acid hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
・ Pd: Palladium (II) nitrate hydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
・Ru: Ruthenium chloride (III) n-hydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
・ Rh: rhodium nitrate (III) (n-hydrate) (manufactured by Wako Pure Chemical Industries, Ltd.)

Next, the metal-containing aqueous solution is added to the powdery precursor material (A) little by little in multiple portions, dried at room temperature (20° C.±10° C.) for 12 hours or more, and precursor material (B) is obtained. got

In addition, when the condition of the presence or absence of additives shown in Tables 1 to 8 is "Yes", polyoxyethylene (15) as an additive is added to the precursor material (A) before adding the metal-containing aqueous solution. Pretreatment was performed by adding an aqueous solution of oleyl ether (NIKKOL BO-15V, manufactured by Nikko Chemicals Co., Ltd.), and then a metal-containing aqueous solution was added as described above. In addition, in the case of "absent" in the condition of the presence or absence of additives, pretreatment with additives as described above was not performed.

The amount of the metal-containing aqueous solution added to the precursor material (A) is determined by the ratio of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing aqueous solution ( Numerical values when converted to the atomic number ratio (Si/M) were adjusted to the values shown in Tables 1-8.

Next, the precursor material (B) impregnated with the metal-containing aqueous solution obtained as described above was calcined in the air at 600° C. for 24 hours to obtain the precursor material (C).

The precursor material (C) obtained as described above was mixed with the structure-directing agents shown in Tables 1 to 8 to prepare a mixed aqueous solution, which was heated at 80 to 350° C. in a closed container at Tables 1 to 8. Hydrothermal treatment was performed under the pH and time conditions shown in . After that, the produced precipitate was filtered off, washed with water, dried at 100° C. for 12 hours or more, and further calcined in the air at 600° C. for 24 hours. After that, the fired product was collected and subjected to a reduction treatment at 400° C. for 350 minutes under an inflow of hydrogen gas to obtain a catalyst structure having a carrier shown in Tables 1 to 8 and fine metal particles as a catalyst substance ( Examples 1-384).

(Comparative example 1)
In Comparative Example 1, MFI-type silicalite was mixed with cobalt oxide powder (II, III) (manufactured by Sigma-Aldrich Japan LLC) having an average particle size of 50 nm or less, and hydrogen reduction treatment was performed in the same manner as in Examples to obtain a carrier. A catalyst structure was obtained in which fine cobalt particles were adhered as a catalyst substance to the outer surface of silicalite as a catalyst. MFI-type silicalite was synthesized in the same manner as in Examples 52 to 57, except for the step of adding metal.

(Comparative example 2)
In Comparative Example 2, MFI-type silicalite was synthesized in the same manner as in Comparative Example 1, except that the step of attaching fine cobalt particles was omitted.

[evaluation]
Various characteristic evaluations were performed under the conditions shown below for the catalyst structures of the above examples and the silicalite of the comparative examples, each having a carrier and a catalyst material.

[A] Observation of cross section For the catalyst structure of the above example comprising a carrier and a catalyst material and the silicalite of Comparative Example 1, observation samples were prepared by a pulverization method and observed with a transmission electron microscope (TEM) (TITAN G2, FEI). (manufactured) was used to observe the cross section.
As a result, it was confirmed that in the catalyst structures of the above examples, the catalyst substance was contained and held inside the carrier made of silicalite or zeolite. On the other hand, in the silicalite of Comparative Example 1, the catalyst substance was attached only to the outer surface of the carrier and was not present inside the carrier.
In addition, for the catalyst structure in which the metal is fine iron particles (Fe) in the above examples, a cross section was cut out by FIB (focused ion beam) processing, and SEM (SU8020, manufactured by Hitachi High-Technologies Corporation), EDX (X-Max, A cross-sectional elemental analysis was performed using HORIBA, Ltd.). As a result, Fe element was detected from inside the carrier.
From the results of cross-sectional observation by TEM and SEM/EDX, it was confirmed that iron fine particles were present inside the carrier.

[B] The average inner diameter of the carrier passage and the average particle diameter of the catalyst material. The minor diameters _were measured, and the average inner diameter was calculated (N=500). In the same manner, 500 catalyst substances were arbitrarily selected from the TEM image, the particle size of each was measured (N = 500), and the average value was obtained. The particle size was defined as D _C. The results are shown in Tables 1-8.
In addition, in order to confirm the average particle diameter and dispersion state of the catalyst substance, analysis was performed using SAXS (small angle X-ray scattering). Measurements by SAXS were performed using Spring-8 beamline BL19B2. The obtained SAXS data was fitted with a spherical model by the Guinier approximation method to calculate the particle size. Particle size was measured for catalyst structures in which the metal was fine iron particles. As a comparative object, commercially available iron fine particles (manufactured by Wako) were observed and measured by SEM.
As a result, the iron oxide fine particles of various sizes with a particle size range of about 50 nm to 400 nm exist randomly in the commercial product, whereas the average particle size obtained from the TEM image is 1.2 nm to 2.0 nm. In the catalyst structure of each example, a scattering peak with a particle size of 10 nm or less was also detected in the SAXS measurement results. From the SAXS measurement results and SEM/EDX cross-sectional measurement results, it was found that catalytic substances with particle sizes of 10 nm or less were present inside the carrier in a highly dispersed state with a uniform particle size.

[C] Relationship between the amount of metal-containing solution added and the amount of metal clathrated inside the carrier Addition amount of atomic number ratio Si/M = 50, 100, 200, 1000 (M = Co, Ni, Fe, Cu) , a catalyst structure in which fine metal particles were included inside the carrier was produced, and then the amount (% by mass) of the metal enclosed inside the carrier of the catalyst structure produced with the above addition amount was measured. In this measurement, the catalyst structures with atomic ratios Si/M = 100, 200, 1000 are the same as the catalyst structures with atomic ratios Si/M = 100, 200, 1000 in Examples 1 to 384, respectively. The catalyst structure with the atomic ratio Si/M = 50 was prepared by adjusting the amount of the metal-containing solution added by the method of No., except that the amount of the metal-containing solution added was changed. = 100, 200 and 1000 catalyst structures.
The amount of metal was quantified by ICP (high frequency inductively coupled plasma) alone or by combining ICP and XRF (X-ray fluorescence analysis). XRF (energy dispersive X-ray fluorescence spectrometer "SEA1200VX", manufactured by SSI Nanotechnology) was performed under the conditions of a vacuum atmosphere and an acceleration voltage of 15 kV (using a Cr filter) or an accelerating voltage of 50 kV (using a Pb filter).
XRF is a method of calculating the amount of metal present based on fluorescence intensity, and a quantitative value (in terms of mass %) cannot be calculated using XRF alone. Therefore, the metal content of the catalyst structure to which the metal was added at Si/M = 100 was quantified by ICP analysis, and the metal content of the catalyst structure to which the metal was added at Si/M = 50 and less than 100 was the result of XRF measurement. and calculated based on the ICP measurement results.
As a result, it was confirmed that at least within the range of the atomic number ratio Si/M of 50 to 1000, the amount of the metal clathrated in the catalyst structure increased as the amount of the metal-containing solution added increased. rice field.

[D] Performance Evaluation The catalyst structures of the above examples and the silicalite of the comparative example, each having a carrier and a catalyst material, were evaluated for the catalytic ability of the catalyst material. The results are shown in Tables 1-8.

(1) Catalytic activity Catalytic activity was evaluated under the following conditions.
First, 0.2 g of the catalyst structure was charged in a normal pressure flow reactor, and nitrogen gas (N ₂ ) was used as a carrier gas (5 ml/min) at 400° C. for 2 hours toluene (VOC model substance) gas. decomposition reaction was performed.
After completion of the reaction, the recovered product gas and product liquid were subjected to component analysis by gas chromatography-mass spectrometry (GC/MS). A TRACE 13 10GC (manufactured by Thermo Fisher Scientific Co., Ltd., detector: thermal conductivity detector) was used as a generated gas analyzer.
Furthermore, based on the results of the above component analysis, the yield (mol%) of compounds having molecular weights smaller than that of toluene (specifically, CO ₂ , CO, HCOH, etc.) was determined. The yield of the above compound was calculated as a percentage (mol%) of the total amount (mol) of compounds having molecular weights smaller than that of toluene contained in the generated gas, relative to the amount (mol) of toluene before the start of the reaction. .
In this example, when the yield of a compound having a molecular weight smaller than that of toluene contained in the generated gas is 80 mol% or more, it is judged that the catalytic activity (decomposition) is excellent, and "⊚", 50 mol% or more. If it is less than 80 mol%, it is determined that the catalytic activity is good, and if it is 20 mol% or more and less than 50 mol%, it is determined that the catalytic activity is not good but is acceptable. Δ”, and when it was less than 20 mol %, it was judged that the catalytic activity was inferior (improper) and was evaluated as “x”.

(2) Durability (service life)
Durability was evaluated under the following conditions.
First, the catalyst structure used in the above evaluation (1) was collected and heated at 650° C. for 12 hours to prepare a heated catalyst structure. Next, using the obtained catalyst structure after heating, decomposition reaction of toluene (VOC model substance) gas is performed by the same method as in the above evaluation (1), and furthermore, the same method as in the above evaluation (1) is performed. The component analysis of the generated gas was performed by the method.
Based on the obtained analysis results, the yield (mol%) of compounds having a molecular weight smaller than that of toluene was determined in the same manner as in the above evaluation (1). Furthermore, compared to the yield of the compound by the catalyst structure before heating (yield determined in the above evaluation (1)), to what extent is the yield of the compound by the catalyst structure after heating maintained? compared whether there are Specifically, the yield of the compound from the catalyst structure after heating (this evaluation (2)) is compared with the yield of the compound from the catalyst structure before heating (yield determined in the evaluation (1)). The percentage (%) of the yield obtained in ) was calculated.
In this example, the yield of the compound from the catalyst structure after heating (yield determined in this evaluation (2)) was the same as the yield of the compound from the catalyst structure before heating (in the evaluation (1) above). Compared to the obtained yield), the durability (heat resistance) is judged to be excellent when 80% or more is maintained, and the durability when 50% or more and less than 80% is maintained. (Heat resistance) is determined to be good and "○", and when 20% or more and less than 50% is maintained, the durability (heat resistance) is not good but is judged to be at a passing level (acceptable). "Δ", and when it was reduced to less than 20%, it was judged that the durability (heat resistance) was inferior (improper) and was evaluated as "x".

Performance evaluations similar to the above evaluations (1) and (2) were also performed for Comparative Examples 1 and 2. Incidentally, Comparative Example 2 is the carrier itself and does not have a catalytic substance. Therefore, in the above performance evaluation, only the carrier of Comparative Example 2 was filled instead of the catalyst structure. Table 8 shows the results.

As is clear from Tables 1 to 8, in the catalyst structures (Examples 1 to 384) in which it was confirmed that the catalyst substance was present inside the carrier by cross-sectional observation, the catalyst substance was simply deposited on the outer surface of the carrier. Compared to the catalyst structure that is only attached (Comparative Example 1) or the carrier itself that does not have any catalytic substance (Comparative Example 2), it exhibits excellent catalytic activity in the decomposition reaction of toluene, and can be used as a catalyst. It was also found to be excellent in durability.

On the other hand, the carrier itself of Comparative Example 2, which does not have any catalytic substance, exhibits almost no catalytic activity in the toluene decomposition reaction, and compared with the catalyst structures of Examples 1 to 384, the catalytic activity and durability are high. Both were inferior.

In addition, the catalyst structure of Comparative Example 1, in which the catalyst substance was attached only to the outer surface of the carrier, had a higher catalytic activity in the toluene decomposition reaction than the carrier itself of Comparative Example 2, which did not have any catalyst substance. Although improved, the durability as a catalyst was inferior to that of the catalyst structures of Examples 1-384.

Reference Signs List 1 Catalyst structure for volatile organic substances 10 Support 10a Outer surface 11 Passage 11a Hole 12 Expanded diameter portion 20 Fine metal particles 30 Fine metal particles D _C average particle diameter D _F average inner diameter D _E inner diameter

Claims (18)

a carrier having a porous structure composed of a zeolite-type compound;
at least one metal volatile organic substance oxidation catalyst inherent in the carrier;
with
the carrier has passages that communicate with each other;
The passageway is defined by the framework structure of the zeolite-type compound, and any one of the one-dimensional, two-dimensional, and three-dimensional pores. has a different diameter expansion part,
the volatile organic matter oxidation catalyst is present in at least the passageway of the carrier ;
the volatile organic substance oxidation catalyst is a metal fine particle,
The average particle size of the fine metal particles is larger than the average inner diameter of the passages, wherein the average inner diameter of the passages constitutes any one of the one-dimensional, two-dimensional, and three-dimensional holes. It is calculated from the average value of the short diameter and long diameter of the hole,
The average particle diameter of the metal fine particles is 0.4 nm to 30 nm,
A catalyst structure for a volatile organic substance, wherein the volatile organic substance oxidation catalyst is included in at least the enlarged diameter portion . 2. The catalyst for volatile organic substances according to claim 1 , wherein said enlarged diameter portion communicates with a plurality of holes constituting any one of said one-dimensional hole, said two-dimensional hole and said three-dimensional hole. Structure. 3. The catalyst structure for volatile organic substances according to claim 1 , wherein the average particle size of said fine metal particles is equal to or smaller than the inner diameter of said enlarged diameter portion. 4. The volatile material according to claim 3 , wherein the metal element (M) of the metal fine particles is contained in an amount of 0.5 to 2.5% by mass with respect to the volatile organic substance catalyst structure. catalytic structures for organic substances. 5. The catalyst structure for volatile organic substances according to any one of claims 1 to 4 , wherein the average particle diameter of said metal fine particles is 0.4 nm to 11.0 nm. The catalyst structure for volatile organic substances according to any one of claims 1 to 5 , characterized in that the ratio of the average particle size of said fine metal particles to the average inner diameter of said passage is 1.1 to 300. body. 7. The catalyst structure for volatile organic substances according to claim 6 , wherein the ratio of the average particle size of said fine metal particles to the average inner diameter of said passage is 1.1-30 . 8. The catalyst structure for volatile organic substances according to claim 7 , wherein the ratio of the average particle size of said fine metal particles to the average inner diameter of said passage is 1.4 to 3.6. The average inner diameter of the passage is 0.1 nm to 1.5 nm,
The catalyst structure for volatile organic substances according to any one of claims 1 to 8 , characterized in that the inner diameter of said enlarged diameter portion is 0.5 nm to 50 nm. Catalyst structure for volatile organic substances according to any one of claims 1 to 9 , characterized in that it further comprises at least one other volatile organic substance oxidation catalyst held on the outer surface of said carrier. . The content of the at least one volatile organic substance oxidation catalyst inherent in the carrier is higher than the content of the at least one other volatile organic substance oxidation catalyst retained on the outer surface of the carrier. The catalyst structure for volatile organic substances according to claim 10 , wherein A catalyst structure for volatile organic substances according to any one of claims 1 to 11 , characterized in that said zeolite-type compound is a silicate compound. A volatile organic substance removal device comprising the volatile organic substance catalyst structure according to any one of claims 1 to 12 . a calcination step of calcining the precursor material (A) , which is an ordered mesoporous material for obtaining a carrier having a porous structure composed of a zeolite-type compound, impregnated with a metal-containing solution (B); ,
a hydrothermal treatment step of mixing the precursor material (C) obtained by sintering the precursor material (B) with a structure-directing agent and performing hydrothermal treatment;
a step of subjecting the hydrothermally treated precursor material (C) to a reduction treatment;
A method for producing a catalyst structure for volatile organic substances, characterized by comprising: 15. The catalyst for volatile organic substances according to claim 14 , characterized in that 50 to 500% by mass of a nonionic surfactant is added to the precursor material (A) before the calcination step. A method of manufacturing a structure. The precursor material (A) is impregnated with the metal-containing solution by adding the metal-containing solution to the precursor material (A) in multiple batches before the firing step. 16. A method for producing a catalyst structure for volatile organic substances according to claim 14 or 15 . When the precursor material (A) is impregnated with the metal-containing solution before the firing step, the amount of the metal-containing solution added to the precursor material (A) is 10 to 1000 in terms of the ratio (atomic ratio Si/M) of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to 17. The method for producing a catalyst structure for volatile organic substances according to any one of claims 14 to 16 , characterized in that the adjustment is made so that 15. The method of claim 14 , wherein the hydrothermal treatment step is performed under a basic atmosphere.

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