JP2019048269A - Porous catalyzer membrane and gas treatment device using the same - Google Patents

Abstract

To provide a catalyzer membrane having improved catalyst activity and a gas treatment device using the same.SOLUTION: There is provided a porous catalyzer membrane having: a membrane supporter area consisted by selecting one or more kind from a group consisting of a solid particle, a fiber, an aggregate of the fiber or the solid particle, and a monolith structure, and supporting a shape maintenance of the membrane; and a catalyzer area which is adjacent to the membrane supporter area in the membrane and porous having pores opening on a membrane surface, in which catalyst particles containing noble metal and/or noble metal oxide are carried in the pore.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a porous catalyst membrane capable of decomposing a compound acting as a harmful component or the like by oxidation, and a gas treatment apparatus using the same.

  Since exhaust gases generated from internal combustion engines such as automobiles and factories contain harmful components such as trace amounts of carbon monoxide, they are released into the atmosphere after they are removed using removing means. Further, in a closed storage or the like, a slight amount of offensive odor may be produced and an ammonia odor may be generated, and various removal means are provided.

  As a method of removing harmful components, adsorption onto adsorbents such as activated carbon, radical by plasma generator, decomposition and removal method by active species such as ozone, etc. are widely used. However, in the adsorption treatment with an adsorbent, there is an upper limit to the adsorption amount of harmful components of the adsorbent, and periodical replacement of the adsorbent is necessary.

  As a method of decomposing and removing harmful components, in addition to a method of oxidizing and decomposing with a physically generated active species such as the above-mentioned plasma method, a method of oxidizing and decomposing using a catalyst is also widely used. There is. As an oxidation catalyst body, in order to widen the contact area, a structure in which an active material (catalyst particles) is supported on a carrier which is inorganic particles is used (Patent Document 1). In addition, a catalyst body in which catalyst particles are supported in the pores of an inorganic mesoporous carrier having cylindrical mesopores has also been developed (patent documents 2 and 3), but the moisture in the air is adsorbed to the pores. There is a problem that the catalyst activity is likely to be gradually reduced by

Furthermore, a composite porous body in which solid fine particles as a catalyst and a porous body are complexed has been proposed (Patent Document 4). Although it has been stated that it has three-dimensional pores and high molecular selectivity, the solid fine particles that are catalysts are outside the pores, and the particle size is a relatively large particle larger than the pore diameter. As compared with the catalyst particles supported in the pores, the specific surface area is not large, and the catalytic activity per unit weight of the composite is not always sufficient.
Patent Document 5 discloses porous particles produced from an acid catalyst, an alcohol, a nonionic surfactant, a metal alkoxide, and at least one particle of metal and metal oxide particles. Some of the oxide particles are used to form porous partition walls, and the pores are only used as adsorption sites for the gas to be treated. There is no mention of catalysis of metal and metal oxide particles, but even if it has the effect, the particle size of the particles is larger than the pore size as in Patent Document 4, so the catalytic activity is not always sufficient. .

  Depending on the intended use, the catalyst body may be adjusted to an appropriate shape, but it is also necessary to contain an appropriate amount of catalyst. In the case of a membrane-like catalyst, the absolute amount of the supported catalyst also depends on the film thickness, so it is desirable to be able to form a thick film. In general, in the case of film formation, it is manufactured by applying a solution in which a component or precursor of a catalyst body is dissolved in a solvent to a substrate. To increase the film thickness, a solution with high viscosity may be used. However, as described in Patent Documents 2 and 3, when the high temperature treatment is performed when forming the pores for supporting the catalyst, detachment of the film and the like occur. It was difficult to form a thick film.

  As a method of forming a thick film, there is disclosed a method of manufacturing a thick film without exposure to high temperature by decomposing an organic compound as a template of pores by UV irradiation in a vacuum state when forming pores. (Patent Document 7). However, the method requires a vacuum device and an ultraviolet irradiation device for production, and also requires several hours of irradiation, which is a costly method. In addition, since the high temperature treatment is performed when the catalyst is supported in the pores, the temperature change at that time may cause distortion, which may cause detachment of the membrane.

Japanese Patent Application Publication No. 2003-080077 JP 2004-283770 A Japanese Patent Application Publication No. 2007-326094 Patent No. 5167482 gazette JP, 2011-006273, A International Publication No. 2013/42328 JP, 2006-130889, A

  All the above-mentioned catalyst bodies have insufficient catalytic activity, and further improvement of the catalytic activity is required. The present inventors have proposed a removal method combining a plasma generation device and a metal fine particle catalyst (Patent Document 6), but the decomposing ability of harmful components is not necessarily sufficient depending on the application, and the purification device is further improved Is also required.

  Then, this invention is made in order to solve the said subject, Comprising: It aims at providing the novel porous catalyst body film | membrane improved about the catalyst activity.

The gist of the present invention is as follows.
[1] A membrane support region which is constituted by one or more selected from the group consisting of solid particles, fibers, fibers or aggregates of solid particles, and monolithic structure, and which helps maintain the shape of the membrane,
A catalyst region which is a porous film having a pore adjacent to the membrane support region in the membrane and opening at the membrane surface, and in which the catalyst particles containing a noble metal and / or a noble metal oxide are supported in the pore And a porous catalyst body membrane characterized by comprising:
[2] The porous catalyst membrane according to [1], wherein the membrane support region is composed of a metal oxide and / or a silicon oxide.
[3] The metal oxide and / or silicon oxide is composed of at least one or more of SiO ₂ , Al ₂ O _3, TiO ₂ , Fe ₂ O ₃ , ZrO ₂ , and CeO ₂ The porous catalyst membrane according to [1] or [2].
[4] The porous catalyst membrane according to any one of [1] to [3], wherein the membrane support region is composed of solid particles and / or solid particle aggregates.
[5] The porous member according to [4], wherein the membrane support region is constituted by a solid particle aggregate, and the solid particle aggregate is a continuous structure in which the particles are sintered. Catalyst membrane.
[6] At least a part of the membrane support region has pores, and catalyst particles containing a noble metal and / or a noble metal oxide are supported on the pores. [1] to [5] ] The porous catalyst body membrane as described in any one of the above.
[7] In any one of [1] to [6], the catalyst particle loading amount of the porous catalyst membrane is 0.050 mg / cm ² or more and 1.000 mg / cm ² or less The porous catalyst body membrane of description.
[8] The film support area is 60% or more and 95% or less by mass ratio with respect to the total of the support area excluding the catalyst particles and the catalyst area [1] to [1] 7] The porous catalyst body membrane as described in any one of 7).
[9] Any of the above-mentioned [1] to [8], wherein the catalyst particle is a particle containing a substance selected from one or more selected from the group consisting of gold, platinum, palladium and oxides thereof. The porous catalyst membrane according to any one of the preceding claims.
[10] A metal oxide in which the porous body in the catalyst body region is one or more selected from the group consisting of SiO ₂ , Al ₂ O ₃ , TiO ₂ , Fe ₂ O ₃ , ZrO ₂ , and CeO ₂ And the porous catalyst membrane according to any one of [1] to [9].
[11] The porous catalyst membrane according to any one of [1] to [10], wherein the particle size of the catalyst particles is 2 nm or more and 9 nm or less.
[12] The supported amount of the catalyst particles is 30% by mass or more and 70% by mass or less with respect to 100% by mass of the catalyst region, described in any one of [1] to [11] Porous catalyst membrane.
[13] The porous catalyst membrane according to any one of [1] to [12], wherein the catalyst region has mesopores.
[14] The porous catalyst membrane according to [13], wherein the average pore diameter of the mesopores measured by the BET method is 3 nm or more and 10 nm or less.
[15] The porous catalyst membrane according to any one of [1] to [14], wherein the porous catalyst membrane is an oxidation reaction catalyst of carbon monoxide or an organic compound.
[16] A film-like body having pores obtained by applying a solution containing solid particles, a hydrolyzate of alkoxysilane or metal alkoxide, and a surfactant to a substrate and then calcining, and contained in the oxidation catalyst particles, Contact with a solution in which the metal compound corresponding to the noble metal and / or noble metal oxide is dissolved,
The porous catalyst according to any one of [1] to [15], which comprises calcining and / or reducing treatment to form oxidation catalyst particles in the pores of the film-like body. Method of manufacturing medium film.
[17] At least a first electrode, a second electrode, and a dielectric disposed between the first electrode and the second electrode, the first electrode and the second electrode A plasma generation unit that generates a plasma by applying a voltage between them to generate a discharge;
A flow path through which a gas to be treated flows, which is formed in a region where the plasma generated by the plasma generation unit is present;
A gas processing apparatus comprising: the porous catalyst membrane according to any one of [1] to [15] disposed in the flow path.

According to the present invention, a catalyst membrane with improved catalyst activity can be provided.
The catalyst membrane of the present invention can be used, for example, in a gas processing apparatus.

It is a figure which shows the outline | summary of a structure of the porous catalyst body film | membrane of this embodiment (solid particle). It is a figure which shows the outline | summary of a structure of the porous catalyst body membrane of this embodiment (fiber). It is a figure which shows the outline | summary of a structure of the porous catalyst body membrane of this embodiment (monolith structure body). It is the figure which represented typically a part of cross section of the gas processing apparatus 200 of 1st Embodiment. It is the figure which represented typically a part of cross section of the gas processing apparatus 300 of 2nd Embodiment. It is the figure which represented typically a part of cross section of the gas treatment apparatus 400 of 3rd Embodiment. It is the figure which represented typically a part of cross section of the gas processing apparatus 500 of 4th Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The porous catalyst body membrane 100 (hereinafter, also simply referred to as “catalyst body membrane”) of the present embodiment is a member having air permeability, and has a catalyst body region 51 and a membrane support region 53. The membrane support region 53 is selected from one or more selected from the group consisting of solid particles, fibers, fibers or aggregates of solid particles, and monolithic structures, and supports the shape of the membrane. The catalyst region 51 is adjacent to the membrane support region 53. In addition, the catalyst region 51 constitutes at least a part of the surface of the porous catalyst membrane, and has open pores in which the gas can flow. The catalyst region 53 further includes noble metal and / or noble metal oxide catalyst particles 55 (hereinafter, may be simply referred to as “catalyst particles”) supported in the pores. 1 shows the case where the membrane support region 53 is a solid particle or a solid particle aggregate, FIG. 2 shows the case where the membrane support region 53 is a fiber or a fiber aggregate, and FIG. 3 shows the membrane support region 53 The cases of monolith structures are shown as schematic diagrams.

  By exposing the gas to be treated to the surface of the catalyst membrane 100 of the present embodiment, the gas to be treated diffuses into the interior of the catalyst membrane 100 through the pores and contacts the catalyst particles 55 in the pores, whereby the gas to be treated is treated. Hazardous components in the product are oxidized and decomposed.

The catalyst film 100 according to the present embodiment is in the form of a film, and is less likely to be in a powdery aggregation form, so the distance between the pores in which the catalyst particles 55 are present and the gas to be processed outside the catalyst film 100 is It tends to be short as compared with a catalyst having pores of other shapes such as powdery (hereinafter also referred to as “conventional catalyst”). Therefore, in the catalyst body film 100 of the present embodiment, the gas to be treated is easily diffused to the inside, and fine particles formed not only in the pores formed in the surface layer portion of the catalyst body film 100 but also in the catalyst body film 100. The gas to be treated can easily reach the holes. For this reason, in the catalyst body film 100 of the present embodiment, all of the catalyst particles 55 contained in the catalyst body film 100 easily come in contact with the gas to be processed.
On the other hand, in the conventional catalyst body, the distance to the gas to be treated outside the catalyst body tends to be longer as compared with the catalyst body film 100 of the present embodiment, so the gas to be treated reaches the pores formed inside. It is difficult to do. For this reason, in the conventional catalyst body, a part of catalyst particles contained in the catalyst body is unlikely to be in contact with the gas to be treated.
Here, when the catalyst particles and a compound to be treated (hereinafter simply referred to as harmful components) such as harmful components contact, the catalyst particles are poisoned to cause harmful components to adhere to the catalyst particles or decompose the harmful components. In some cases, the reaction intermediate formed may adhere to the catalyst particles and the catalytic activity of the catalyst may be lost. In the conventional catalyst body, the deposition tends to occur more on the catalyst because the gas to be treated is easily in contact with a part of the catalyst. As a result, even if all of the catalyst particles contained in the catalyst body are not poisoned, the catalyst activity of the catalyst body is easily lost. That is, conventional catalyst bodies have difficulty in maintaining catalytic activity.
However, in the catalyst membrane 100 of the present embodiment, the catalyst particles contained in the catalyst membrane 100 are more easily in contact with the gas to be treated, so the activity of the catalyst membrane is maintained until all catalyst particles are poisoned. . Therefore, the catalyst membrane 100 of the present embodiment can maintain the catalyst activity for a long time.

  Further, as described above, in the catalyst body film 100 of the present embodiment, the gas to be treated is easily diffused inside, so when moisture in the gas to be treated is adsorbed in the pores, the concentration of water to the gas to be treated A gradient is likely to occur. Therefore, re-diffusion of the adsorbed water to the gas to be treated proceeds, and as a result, there is an effect that the adsorbed water is suppressed to a fixed amount. On the other hand, in the conventional catalyst, the distance from the pores inside the powder to the gas to be treated outside the catalyst is relatively long, and in particular, the re-diffusion of water adsorbed inside the powder is difficult to occur. . For this reason, it is presumed that clogging of pores by the adsorbed water is likely to occur, and the catalytic activity is reduced.

  The catalyst film 100 of the present embodiment can be formed, for example, on the substrate 57. At this time, it is not particularly limited whether the substrate has air permeability. In the case where the catalyst film 100 of the present embodiment is disposed on the non-air-permeable substrate 57, the surface of the catalyst film 100 may be embossed by embossing or the like. When the unevenness is formed on the surface of the catalyst film 100, the contact area between the gas to be treated and the catalyst film is increased, so that the oxidation reaction of harmful components and the like in the gas to be treated can be further promoted.

  As long as the base material 57 on which the catalyst film 100 is formed has an air-permeable shape such as a honeycomb shape or a mesh shape, the process gas may be circulated in the thickness direction of the catalyst film 100. The catalyst film 100 of the present embodiment may be formed on both sides of the substrate 57, and which form to use is determined according to the design of the apparatus incorporating the catalyst film 100 of the present embodiment. Good.

Although the film thickness of the catalyst film 100 of the present embodiment is not particularly limited, it is desirable that the film thickness be 300 nm or more and 5,000 nm or less.
If it is less than 300 nm, the absolute amount of the catalyst particles 55 that can be supported on the catalyst region 51 is reduced as compared with the case where it is within the above range, so it is difficult to sufficiently decompose harmful components in the gas to be treated Become. If the thickness is larger than 5,000 nm, the gas to be treated is less likely to diffuse into the catalyst film 100, and the catalyst particles in the catalyst film 100 are less likely to come in contact with the gas to be treated. In addition, the water adsorbed in the mesopores present inside the catalyst membrane 100 is less likely to be diffused again, the amount of water adsorbed in the mesopores increases, and the action of the catalyst particles is likely to be inhibited. For this reason, compared with the case where it is in the said range, it becomes difficult to maintain the catalyst activity of the catalyst membrane 100. The film thickness of the catalyst film 100 of the present embodiment can be measured by observing the cross section of the catalyst film 100 by TEM and measuring the size of the cross-sectional image.

  The catalyst body film 100 of the present embodiment can decompose harmful components in the gas to be treated into an innocuous substance such as carbon dioxide or water by an oxidation reaction, and discharge it into the atmosphere. As compounds that can be treated in the catalyst body film 100 of the present embodiment, substances that volatilize from materials such as automobile interior materials, house construction materials and interior materials, housings and members of home appliances, for example, paints, adhesives, cleaning Substances that volatilize from organic solvents such as Specifically, hydrocarbons such as ethylene, benzene, xylene, toluene, ethylbenzene and styrene, alcohols such as methanol, ethanol and propyl alcohol, aldehydes such as formaldehyde and acetaldehyde, ketones such as acetone and ethyl methyl ketone And ammonia. In addition, carbon monoxide produced by incomplete combustion of cigarettes and burning processes in factories and kitchens, household heaters, etc. can also be treated.

The film support region 53, which is a component of the present embodiment, may be made of any of an inorganic material, an organic material, and an inorganic-organic composite material, and the type of gas to be treated and the catalyst film are applied. It may be selected according to the device and various environmental conditions. Among these, it is preferable to use an inorganic material having higher heat resistance, because high temperature treatment is performed at the time of pore formation of the porous body. Examples of the inorganic material include γ-Al ₂ O ₃ , α-Al ₂ O ₃ , θ-Al ₂ O ₃ , η-Al ₂ O ₃ , amorphous Al ₂ O ₃ , TiO ₂ , ZrO ₂ and SnO _2. , SiO ₂ , MgO, ZnO ₂ , Bi ₂ O ₃ , In ₂ O ₃ , In ₂ O ₃ , MnO ₂ , Mn ₂ O ₃ , Nb ₂ O ₅ , FeO, Fe ₂ O ₃ , Fe ₃ O ₄ , Sb ₂ O ₃ , CuO , Cu ₂ O, NiO, Ni ₃ O ₄ , Ni ₂ O ₃ , CoO, Co ₃ O ₄ , Co ₂ O ₃ , WO ₃ , CeO ₂ , Pr ₆ O ₁₁ , Y ₂ O ₃ , In ₂ O ₃ , A single inorganic oxide such as PbO or ThO ₂ can be mentioned. Also, for example, SiO ₂ -Al ₂ O ₃ , SiO ₂ -B ₂ O ₃ , SiO ₂ -P ₂ O ₅ , SiO ₂ -TiO ₂ , SiO ₂ -ZrO ₂ , Al ₂ O ₃ -TiO ₂ , Al ₂ O ₃ -ZrO ₂ , Al ₂ O ₃ -CaO, Al ₂ O ₃ -B ₂ O ₃ , Al ₂ O ₃ -P ₂ O ₅ , Al ₂ O ₃ -CeO ₂ , Al ₂ O ₃ -Fe ₂ O _{3 , TiO 2 -CeO 2, TiO 2} -ZrO 2, TiO 2 -WO 3, ZrO 2 -WO 3, SnO 2 -WO 3, CeO 2 -ZrO 2, SiO 2 -TiO 2 -ZrO 2, Al 2 O 3 substance constituting the _{-TiO 2 -ZrO 2, SiO 2 -Al} 2 O 3 -TiO 2, SiO 2 -TiO 2 -CeO 2, composite oxides such as cerium-zirconium-bismuth composite oxide even film support region 53 Can be mentioned as
For example, one or more of the single inorganic oxide and the composite oxide may be included in the catalyst film 100 as a material constituting the film support region 53 according to the present embodiment. In particular, the below-mentioned solid particles and the like may be constituted of these substances. Note that the cerium-zirconium-bismuth composite oxide is a solid solution represented by the general formula _{Ce 1-X-Y Zr X} Bi Y O 2-δ, X, Y, the value is 0.1 ≦ X ≦ each [delta] 0 .3, 0.1 ≦ Y ≦ 0.3, and 0.05 ≦ δ ≦ 0.15.
Among them, the film support region is preferably composed of metal oxide and / or silicon oxide from the viewpoint of the above heat resistance, and SiO ₂ , Al ₂ O _3, TiO ₂ , Fe ₂ O ₃ , ZrO _{2 2,} and it is more preferable that among the CeO ₂ is composed of at least one or more.

  The material of the membrane support region 53 and the material of the catalyst region 51 may be the same or different. However, the film support region 53 and the catalyst region 51 are strongly connected if they are the same. It is more preferable because a membrane-like catalyst body firmly bonded to is obtained.

Depending on the application, the catalyst needs to contain a necessary amount of catalyst, but the amount of catalyst particles supported on the catalyst membrane 100 is 0.050 mg / cm ² or more and 1.000 mg / cm ² or less Is preferred. If it is less than 0.050 mg / cm ² , the catalytic activity of the catalyst membrane is lower than in the case of 0.050 mg / cm ² or more, and harmful components in the gas to be treated can not be sufficiently removed. . If it exceeds 1.000 mg / cm ² , the film thickness becomes too thick, which makes the catalyst film easily detached, or the catalyst particles aggregate to lower the catalytic activity, which is not preferable.
In the case of a membrane-like catalyst as in this embodiment, the absolute amount of the supported catalyst depends on the film thickness. The catalyst support film 100 of the present embodiment contains the film support region 53, so that the film support region 53 acts as a thickener for the precursor in the manufacturing process described later, and also as a scaffold for film formation. By functioning, it is easier to form a thicker membrane compared to a membrane without a membrane support area. In other words, the membrane support region 53 assists in maintaining the shape of the membrane and contributes to the provision of a membrane of the intended thickness. On the other hand, in the case where the membrane support region is not contained, when the membrane is exposed to high temperature when forming the pores, desorption of the membrane itself occurs, and it is difficult to maintain the thickness of the membrane. By increasing the film thickness, the supported amount of catalyst particles can be increased, and the catalyst film 100 with higher catalytic activity can be obtained.

  For example, in the method for producing a catalyst membrane described later, a solution containing a surfactant serving as a template, a hydrolyzate of metal alkoxide and solid particles (hereinafter referred to as “precursor solution”) is applied to a substrate and heated Thus, the solvent is volatilized to obtain a film. When using a precursor solution that does not contain the material that forms the membrane support region, it is difficult to form a thick film because the viscosity of the precursor solution is low.

The membrane support region 53 is configured by selecting one or more types of materials from the group consisting of solid particles, fibers, solid particle aggregates, fiber aggregates, and monolith structures in a catalyst body film.
There is no particular limitation on the method of forming the catalyst film so as to include the film support region, but the film support region and the catalyst are dispersed by, for example, dispersing the material constituting the film support region in the solution containing the raw material of the catalyst region. The regions may be simultaneously formed in the form of a film, and after forming the film support region in the form of a film on the base material, the catalyst region is formed in the space existing around the film support region. The catalyst membrane may be obtained by

When the film support region 53 is composed of solid particles, the average particle diameter of the solid particles is not particularly limited, but the average particle diameter of the solid particles is preferably 0.01 μm or more and 1 μm or less. Solid particles of 0.01 μm or less are difficult to manufacture, and if 1 μm or more, the solid particles are uniformly dispersed in the film because they are easily precipitated in the precursor solution of the catalyst region in the process of manufacturing the catalyst film. It becomes difficult to produce a catalyst membrane.
The average particle diameter of the solid particles can be measured using a TEM as in the case of the catalyst particles described later.

  When the membrane support region 53 is a fiber, the average fiber diameter and the average fiber length are not particularly limited, but the average fiber diameter is preferably 0.01 μm to 1 μm, and the average fiber length is preferably 1 μm to 100 μm. When the average fiber diameter is less than 0.01 μm or the average fiber length is less than 1 μm, the fibers are difficult to manufacture, and when the average fiber diameter is 1 μm or more or when the average fiber length is 100 μm or more, the catalyst film is manufactured. In the process, the fibers easily settle in the precursor solution in the catalyst region, which makes it difficult to produce a catalyst film in which the fibers are uniformly dispersed in the film. In addition, an average fiber diameter and an average fiber length can also be measured using TEM.

A solid particle aggregate is an aggregate in which solid particles that are constituent units are physically fixed, and includes particles (secondary particles) in which a large number of solid particles (primary particles) are collected. Further, at least a part of the primary particles may be in a continuous body chemically bonded to each other by sintering or the like.
The average particle diameter of the solid particle aggregate is preferably 0.01 μm or more and 1 μm or less as in the case of the solid particles. Solid particle aggregates less than 0.01 μm are difficult to manufacture, and when larger than 1 μm, solid particle aggregates are in the film because they are easily precipitated in the precursor solution of the second region in the catalyst membrane manufacturing process. It becomes difficult to produce a uniformly dispersed catalyst membrane.

The fiber assembly is, like the solid particle assembly, an assembly in which fibers are physically fixed, includes fibers (secondary fibers) in which a large number of fibers (primary fibers) are collected, etc., and at least a part of the primary fibers It may be a continuous body chemically bonded to each other by sintering or the like. In addition, the fiber assembly may be a fiber structure composed of a woven fabric, a net, a non-woven fabric, and the like. In addition, the membrane support region 53 may be a monolithic structure which is an integral structure having a mesh-like continuous structure.
As described above, various shapes of materials can be used as the film support region 53, but the solid particles or solid particle aggregates are desirably dispersed by dispersing them in a porous precursor solution in the process of producing a catalyst film described later. Is preferable because it can be easily produced. In addition, when the solid particles or the solid particle aggregate are composed of solid particles having pores, the catalyst particles can be supported also in the pores, so that the catalytic activity of the catalyst membrane can be further enhanced. Yes, even more preferable.

Moreover, it is also preferable to use a material having adsorption activity of harmful components, such as zeolite and activated carbon, as the membrane support region 53. When the harmful component more than the oxidative decomposition ability of the supported catalyst particles is supplied to the catalyst membrane, the flow rate of the gas to be treated increases, the concentration of harmful components in the non-treatment gas increases, etc. If 53 does not have adsorption activity, harmful components exceeding the oxidative degradation capacity pass through the catalyst membrane without oxidative degradation.
On the other hand, when the membrane support region 53 has adsorption activity, even if harmful components more than the oxidative decomposition ability of the catalyst particles are temporarily supplied to the catalyst film, the harmful components exceeding the treatment capacity of the catalyst particles are film supported Once adsorbed to the body region 53, the harmful component is released from the membrane support region 53 when the supply amount of the harmful component decreases, and is oxidized and decomposed by the catalyst particles. Therefore, the amount of oxidative decomposition can be equalized, and a catalyst membrane that can cope with fluctuations in the supply of harmful components can be obtained.

  The ratio of the membrane support area to the total of the membrane support area excluding the catalyst particles and the catalyst area is preferably 60% to 95% by weight, more preferably 70% to 90%. is there. When the membrane support area is 60% or more, the amount of supported catalyst particles is increased as compared with the case of less than 60%, which is preferable because the catalytic activity becomes higher. On the other hand, if it exceeds 95%, for example, the viscosity of the precursor solution becomes high in the production process of the catalyst membrane described later, and it becomes difficult to uniformly apply the solution on the substrate. It is not preferable because it becomes difficult compared to the case of% or less.

  The catalyst region 51, which is a component of the catalyst membrane of the present embodiment, is a porous body and has pores, but if the pores are mesopores, the activity of the catalyst particles supported in the pores is It is preferable because it increases. In the present specification, mesopores refer to pores communicating with at least two openings formed on the surface of the catalyst region 51 and having a diameter of 2 nm or more and 50 nm or less. The shape of the mesopores and the positional relationship of the openings thereof are not particularly limited. For example, a cylinder shape (for example, mesopores) extending in the same straight line toward two opposing surfaces of the surface of the catalyst region 51 (for example, The honeycomb structure may be a so-called communication structure in which mesopores are branched inside the catalyst region 51 and connected to other mesopores. Among these, in the communication structure, one mesopore is connected to a larger number of openings as compared with a cylinder shape or the like, so the gas to be treated is easily diffused to the inside of the catalyst film 100 and the inside of the mesopore Even if catalyst particles formed in the opening portion are formed, the air permeability is unlikely to be impaired. Further, even if water adheres to the mesopores in the catalyst region 51, the air permeability is not easily impaired. For this reason, the communication structure is more preferable. Here, the diameter of the mesopores is preferably 3 nm or more and 10 nm or less. When the diameter of the mesopores is within the above range, the particle diameter of the supported catalyst particles 55 is also within the above range, and the specific surface area of the catalyst particles becomes larger compared to the catalyst particles 55 having a particle diameter exceeding 10 nm. Because of the ease, a catalyst membrane with higher activity can be obtained. In addition, the catalyst particles 55 are supported on the mesopores, whereby the catalyst particles 55 are less likely to aggregate and the catalyst activity is further maintained. The diameter of the mesopores in the catalyst region 51 according to the present embodiment is the average diameter of the mesopores formed in the catalyst region 51, and the automatic specific surface area / thin diameter by BET method based on JIS-Z-8831 is It is a value measured using a hole distribution measuring device.

  The catalyst particle 55 which is a component of the catalyst body film 100 of the present embodiment may be a particle containing a noble metal or a noble metal oxide having catalytic activity for promoting an oxidation reaction, or both, and is not particularly limited.

As used herein, noble metals refer to gold, silver and ruthenium of the platinum group, rhodium, palladium, osmium, iridium and platinum. The noble metal oxides are oxides of the above-mentioned noble metals and their hydrates, and more specifically, Au ₂ O ₃ , Ag ₂ O, AgO, Ag ₂ O.Ag ₂ O ₃ , RuO ₂ , RuO ₄ , Rh ₂ It refers to O ₃ , PdO, OsO ₂ , OsO ₄ , IrO ₂ , Ir ₂ O ₃ .nH ₂ O, PtO ₂ , PtO ₂ .H ₂ O, platinum black and the like.
Preferably, the catalyst particles 55 are composed of at least one of gold (Au), platinum (Pt), palladium (Pd) and their oxides, which have higher oxidation catalytic ability. As the catalyst particles 55, one or more of Au, Pt, Pd, Au ₂ O ₃ , Ag ₂ O, Ag ₂ O, Ag ₂ O.Ag ₂ O ₃ , PdO, PtO ₂ , PtO ₂ · H ₂ O, platinum black, etc. The particle comprised can be mentioned.

  The particle size of the catalyst particles 55 is smaller than the diameter of the mesopores because the catalyst particles 55 are supported in the mesopores, but the catalyst particles 55 supported in the mesopores and the gas to be treated diffused in the mesopores It is desirable that the particle size of the catalyst particles 55 be 90% or less of the diameter of the mesopores, in order to secure a sufficient passage for the gas to be treated to contact. When the particle size is larger than 90%, the gas to be treated hardly diffuses to the inside of the catalyst film 100 as compared with the case of 90% or less, and it becomes difficult to maintain the catalyst activity for a long time. Decomposing efficiency of harmful components in it tends to decrease. In addition, if the particle size of the catalyst particles 55 is 9 nm or less (more preferably 2 nm or more and 6 nm or less), the specific surface area of the catalyst particles is increased and the catalyst activity is dramatically increased as compared to the case where the particle size exceeds 9 nm. It improves and the decomposition efficiency of harmful components in the gas to be treated is further enhanced. Therefore, the particle size of the catalyst particles 55 is more preferably 9 nm or less. In addition, when the catalyst particles 55 are metal or metal oxide when the particle size is smaller than 2 nm, they are very unstable as a substance, and the catalyst activity tends to be low. In addition, the particle size of the catalyst particles 55 is obtained by acquiring an image photograph of the catalyst particles 55 using a transmission electron microscope (TEM), and 300 or more catalyst particles 55 randomly extracted from the catalyst particles 55 shown in the image photograph. It is the value which measured the Feret diameter of and arithmetically averaged the Feret diameter. In the image of the catalyst particle which can be confirmed by TEM, the Feret diameter is the two longest distance among the straight lines parallel to any straight line passing (including being in contact with) the catalyst particle. It is the distance between parallel lines.

  The loading amount of the catalyst particles 55 is preferably 30% by mass or more and 70% by mass or less, and more preferably 40% by mass or more and 70% by mass or less with respect to 100% by mass of the catalyst region in the state of supporting the catalyst particles. It is mass% or less, More preferably, they are 50 mass% or more and 70 mass% or less. When it exceeds 70% by mass, the catalyst particles are easily aggregated with each other, and the catalytic activity is likely to be reduced as compared with the case of being in the above range. Moreover, if it is less than 30 mass%, compared with the case where it exists in the said range, sufficient catalyst activity is hard to be acquired. In order to support 30% by mass or more of catalyst particles 55 having a particle diameter of 2 nm or more and 9 nm or less, it is difficult if the pores do not have mesopores.

  In addition to the catalyst particles, the catalyst film 100 of the present embodiment may contain promoter particles, metals other than noble metals, metal oxides, and the like, and is not particularly limited. Specifically, the composite catalyst may be one in which co-catalyst particles and catalyst particles are mixed, or a composite catalyst composed of composite particles in which metal elements other than noble metals are complexed with the catalyst particles. In the case of using the catalyst particles alone or in the case of using a mixture of catalyst particles and co-catalyst particles, the catalyst particles can be in the above-mentioned size range (particle diameter is 2 nm or more and 9 nm or less). Further, in the case of composite particles in which a metal element other than a noble metal is complexed with catalyst particles, the size of the composite particles can be set within the above-described size range (particle diameter is 2 nm or more and 9 nm or less). Examples of metal particles (nanoparticles) other than catalyst particles that can be used in cocatalyst particles or composite catalysts include base metals and oxides thereof. Two or more types of these noble metals and their oxides, base metals and particles of their oxides may be mixed and supported on the inner surface of mesopores formed in the catalyst region 51.

  The catalyst region 51 according to the present embodiment is preferably made of silicon oxide or metal oxide. The catalyst region 51 made of silicon oxide or metal oxide can act on the catalyst particles 55 to improve the catalytic activity of the catalyst film. The catalyst region 51 formed of other materials than silicon oxide or metal oxide is less likely to act on the catalyst particles, and it is difficult to improve the catalyst activity of the catalyst particles. In addition, in the case of the catalyst region 51 formed of silicon oxide or other material other than metal oxide, the activity of the catalyst particles is increased by using the co-catalyst particles, but the upper limit for the amount of particles that can be supported porously If both the promoter particles and the catalyst particles are supported in a porous manner, there is a limit to increase the supported amount of catalyst particles (for example, 10% by mass of catalyst particles relative to 100% by mass of the catalyst region) More difficult to carry). Furthermore, metal oxides are preferable because they have heat resistance and physical properties are unlikely to change when subjected to a high temperature state in the manufacturing process.

The metals are Group 1 (excluding H), Groups 2 to 12, 13 (excluding B), 14 (excluding C and Si), and 15 (excluding N, P and As) in the periodic table. , And elements belonging to Group 16 (except O, S, Se, and Te), and lanthanoids and actinoids. As metal oxides, for example, γ-Al ₂ O ₃ , α-Al ₂ O ₃ , θ-Al ₂ O ₃ , η-Al ₂ O ₃ , amorphous Al ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ MgO, ZnO ₂ , Bi ₂ O ₃ , In ₂ O ₃ , In ₂ O ₃ , MnO ₂ , Mn ₂ O ₃ , Nb ₂ O ₅ , FeO, Fe ₂ O ₃ , Fe ₃ O ₄ , Sb ₂ O ₃ , CuO, Cu _{2 O, NiO, Ni 3 O} 4, Ni 2 O 3, CoO, Co 3 O 4, Co 2 O 3, WO 3, CeO 2, Pr 6 O 11, Y 2 O 3, In 2 O 3, PbO, Metal oxides such as ThO ₂ can be mentioned. Also, metal oxides, _{e.g., Al 2 O 3 -TiO 2,} Al 2 O 3 -ZrO 2, Al 2 O 3 -CaO, Al 2 O 3 -CeO 2, Al 2 O 3 -Fe 2 O 3, _{TiO 2 -CeO 2, TiO 2 -ZrO} 2, TiO 2 -WO 3, ZrO 2 -WO 3, SnO 2 -WO 3, CeO 2 -ZrO 2, Al 2 O 3 -TiO 2 -ZrO 2, cerium-zirconium A complex oxide containing two or more metals such as bismuth complex oxide may be used. For example, the catalyst region 51 according to the present embodiment may be configured of one or more of these metal oxides. Note that the cerium-zirconium-bismuth composite oxide is a solid solution represented by the general formula _{Ce 1-X-Y Zr X} Bi Y O 2-δ, X, Y, the value is 0.1 ≦ X ≦ each [delta] 0 .3, 0.1 ≦ Y ≦ 0.3, and 0.05 ≦ δ ≦ 0.15.

In the case where the catalyst film 100 of the present embodiment also has a function as the dielectric 13 described later, the catalyst region 51 may be formed of a metal oxide at least a part of which is an insulator. As a metal oxide to be an insulator, for example, ZrO ₂ , γ-Al ₂ O ₃ , α-Al ₂ O ₃ , θ-Al ₂ O ₃ , η-Al ₂ O ₃ , amorphous Al ₂ O ₃ , Magnesium titanate, barium titanate and the like can be mentioned. By forming the dielectric 13 from a metal oxide, plasma resistance and heat resistance can be improved.

The silicon oxide or metal oxide forming the catalyst region 51 is preferably at least one or more of SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , TiO ₂ , ZrO ₂ and CeO ₂ . The catalyst region 51 formed of at least one or more of SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , TiO ₂ , ZrO ₂ and CeO ₂ can support the catalyst particles 55 more firmly, so 55 is hard to aggregate. Further, it can be more firmly adhered to the base material 57, and it is more desirable because it easily acts on the catalyst particles 55 and the catalytic activity of the catalyst particles 55 is higher than other metal oxides and the like.

  The catalyst membrane 100 of the present embodiment can be formed on the substrate 57 as described above. By using a base material, it works as a support for a film precursor to be described later, so that it can be easily formed into a film shape at the time of producing the catalyst film 100, which is preferable. As described above, the base material 57 may have a non-air-permeable structure such as a plate shape or a structure having air-permeability. The air-permeable structure is, for example, a sheet-like one having a large number of through holes formed by punching, a fiber, a cloth, a mesh, and a fiber composed of a woven fabric, a net, a non-woven fabric, etc. A structure (filter-like) can be mentioned. In addition, those of various shapes and sizes suitable for the purpose of use can be appropriately used.

  Since the base material 57 on which the catalyst film 100 is formed may be heated to a high temperature when forming a film-like body, it is desirable to use a material having heat resistance to withstand the heating temperature. Specifically, metal materials, ceramics, glass, carbon fibers, silicon carbide fibers, heat-resistant organic polymer materials, and the like are preferable, and metals, metal oxides, and glasses are more preferable.

  As metal materials used for the base material 57, refractory metals such as tungsten, molybdenum, tantalum, niobium, TZM (Titanium Zirconium Molybdenum), W-Re (tungsten-rhenium), noble metals such as silver, ruthenium and the like, and metals thereof Alloys or oxides, special metals such as titanium, nickel, zirconium, chromium, inconel, hastelloy, etc., general metals such as aluminum, copper, stainless steel, zinc, magnesium, iron and alloys containing these general metals or oxidation of these general metals A thing can be used. Moreover, you may use the member in which the film of the metal, the alloy, or the oxide mentioned above was formed by various plating, vacuum evaporation, CVD method, a sputtering method etc. as a metal material.

  Furthermore, as ceramics used for the base material 57, ceramics, such as earthenware, pottery, ceramic, ceramics such as magnetism, cement, gypsum, enamel, and fine ceramics can be mentioned. The composition of the ceramic may be elemental, oxide, hydroxide, carbide, carbonate, nitride, halide, phosphate or the like, and a composite thereof May be.

  Moreover, as ceramics used for the base material 57, barium titanate, lead zirconate titanate, ferrite, alumina, forsterite, zirconia, zircon, mullite, steatite, cordierite, aluminum nitride, silicon nitride, and the like are further used. Ceramics such as silicon carbide, new carbon, high strength ceramics, functional ceramics, superconductive ceramics, nonlinear optical ceramics, antibacterial ceramics, biodegradable ceramics, bioceramics and the like can be mentioned.

  Moreover, as glass used for the base material 57, soda lime glass, potash glass, crystal glass, quartz glass, chalcogen glass, uranium glass, water glass, polarizing glass, tempered glass, laminated glass, heat resistant glass / borosilicate glass, bulletproof Glass, glass fiber, dichroic, gold stone (brown gold stone, sand gold stone, purple gold stone), glass ceramics, low melting point glass, metallic glass, new glass, and glass such as saffilet can be mentioned.

  In addition to the base material 57, ordinary portland cement, early strength portland cement, ultra early strength portland cement, moderate heat portland cement, low heat portland cement, sulfate resistant portland cement, and portland cement with blast furnace slag, fly ash, It is also possible to use cements such as blast furnace cement, silica cement, and fly ash cement which are mixed cements to which a siliceous mixed material is added.

  In addition, as the base material 57, it is possible to use titania, zirconia, alumina, ceria (cerium oxide), zeolite, apatite, silica, activated carbon, diatomaceous earth or the like. Furthermore, it is also possible to use a metal oxide composed of chromium, manganese, cobalt, nickel, tin or the like as the base material.

  Furthermore, the base material 57 may be made of polyimide, polyetheretherketone, polyphenylene sulfide, polyaramid, polybenzothiazole, polybenzoxazole, polybenzimidazole, polyquinoline, polyquinoxaline, fluorine resin, etc., or heat such as phenol resin or epoxy resin It is also possible to use heat-resistant organic polymer materials known to those skilled in the art, such as curable resins.

  Next, an example of a method of obtaining the catalyst membrane 100 of the present embodiment will be described. In the method, solid particles are used as a material for forming the film support region 53, and a film-like precursor is first formed. The film-like body containing the porous material having pores forms, for example, a precursor of the film-like body on a substrate in a state of containing a substance acting as a mesopore template in the porous inside, and then the template It can be obtained by decomposing and removing the substance acting as.

A specific example of the method will be described. First, a solution (hereinafter, referred to as “precursor solution”) containing a surfactant serving as a template, a hydrolyzate of metal alkoxide and solid particles is prepared. More specifically, for example, a metal alkoxide is added to a solution in which a surfactant is dissolved, and pH adjustment is performed to hydrolyze the metal alkoxide. This produces a metal hydroxide. Surfactants form micelles in solution and become templates for mesopores. Furthermore, solid particles are added to the obtained solution and dispersed to obtain a precursor solution. The order of adding the solid particles is not particularly limited, and the metal alkoxide may be added after the solid particles are added to the solution in which the surfactant is dissolved.
The precursor solution is applied to a substrate, and the solvent is volatilized by heating, and the metal hydroxide is condensed and cured to form a film-like precursor on the substrate surface. Thereafter, by further baking at a high temperature of 300 ° C. or more, the surfactant which is a template in the precursor is removed by decomposition and volatilization, and a catalyst having a membrane support region 53 constituted by solid particles and pores A film-like body including the medium region 51 is obtained. The heating of the precursor solution applied to the substrate and the firing of the film-like precursor may be performed simultaneously, and when these are simultaneously performed, the precursor solution applied to the substrate is heated to 300 ° C. The firing may be performed as above.

  The precursor solution can include, for example, four components of (1) hydrolyzate of metal alkoxide, (2) solvent (solvent), (3) surfactant, and (4) solid particle. In the case of obtaining a hydrolyzate by subjecting a metal alkoxide to a hydrolysis treatment in a solution to obtain a hydrolyzate, it is preferable to use water or a mixed solvent of water and an alcohol such as ethanol or methanol since water is required. . In addition, a catalyst for hydrolyzing the metal alkoxide may be further contained in the solution, and it is preferable to use an acid such as nitric acid or hydrochloric acid as the catalyst. The blending ratio (blending amount) of the surfactant to be blended to obtain the precursor solution and the blending ratio (blending amount) of the metal alkoxide are not particularly limited, can be appropriately set, and are not particularly limited. By changing the molar ratio of surfactant to metal alkoxide (surfactant (mol) / metal alkoxide (mol)), it is possible to control the volume fraction of pores and the porosity in the resulting catalyst region 51. In addition, the specific surface area of the catalyst region 51, the volume of the pores (hereinafter, also referred to as "pore volume"), the diameter of the pores (hereinafter referred to as "pore volume") , "Pore diameter" can be controlled.

  In addition, it is preferable from the viewpoint of formation of a catalyst body film (film-like body) having a uniform film thickness that it is not acidic (pH is less than 7) that precipitates are not generated in the precursor solution before application to a substrate. The formation of precipitates can be avoided by using the alcohol of Alternatively, only the molar ratio of water to metal alkoxide is adjusted, the molar ratio is adjusted with pH adjustment, alcohol is added with pH adjustment, or the adjustment of molar ratio and alcohol is added It is also possible to avoid the formation of precipitates by doing both.

As the surfactant, polyoxyethylene ether, polyalkylene oxide block copolymer and the like can be used. The polyoxyethylene ether _{C 12 H 25 (CH 2 CH} 2 O) 10 OH, C 16 H 33 (CH 2 CH 2 O) 10 OH, C 18 H 37 (CH 2 CH 2 O) 10 OH, C 12 H ₂₅ (CH ₂ CH ₂ O) ₄ OH, C ₁₆ H ₃₃ (CH ₂ CH ₂ O) ₂ OH and the like can be mentioned. Polyalkylene oxide block copolymers include block copolymers of ethylene oxide and propylene oxide.

  Since the chain length of the surfactant affects the diameter of the pores, the surfactant may be selected according to the diameter of the intended pore. Alternatively, a hydrophobic compound such as mesitylene may be added to the precursor solution, and since the hydrophobic compound can increase the micelle diameter in the precursor solution, it can be used to adjust the pore diameter. .

  As the metal alkoxide, tetrapropoxyaluminum, tetrapropoxytin, tetrapropoxytitanium, tetrapropoxyzirconium and the like can be used.

  The precursor solution can be applied to the substrate by any method as long as the precursor solution can be applied uniformly and thinly, but the spin coating method or the dip & blow method that blows off unnecessary solution after immersing the substrate in the precursor solution Applicable The method of applying the precursor solution may be selected in accordance with the shape of the substrate to be applied. Also, the heating conditions for removing the template molecule (surfactant (micelle)) after forming the porous precursor are not particularly limited. For example, if the precursor of the film-like body is heated at 300 to 600 ° C. Good.

  Next, the catalyst particles are supported by the pores in the catalyst region 51 of the film-like body to obtain the catalyst film of the present embodiment. First, the pores of the membrane are brought into contact with a solution in which the noble metal compound is dissolved and / or dispersed (hereinafter referred to as “precious metal compound solution”), and the noble metal compound solution is Introduce. Thereafter, reduction treatment is performed to form catalyst particles in the pores of the catalyst region 51, whereby the catalyst film of the present embodiment can be obtained.

  Specifically, for example, after a film-like body is immersed in a noble metal compound solution, reduction treatment can be performed. More specifically, while the noble metal compound solution is heated to 20 to 90 ° C., preferably 50 to 70 ° C. and stirred, the pH is adjusted to 3 to 10, preferably 5 to 8, using an alkaline solution. Thereafter, the base material having a filmy body formed on the surface thereof is immersed in a noble metal compound solution, followed by vacuum degassing to make the noble metal compound solution penetrate the pores, and then heated at 200 to 300 ° C. Baking to perform reduction treatment.

  Also, instead of heating and baking at 200 to 300 ° C., a hydrogen reduction method using a hydrogen stream at 100 to 200 ° C., a liquid phase reduction method to be immersed in a sodium borohydride solution, and microwave heating with ethylene glycol added. The noble metal compound may be reduced by a known method such as a wave method.

Examples of noble metal compounds include gold compounds such as HAuCl ₄ · 4H ₂ O, NH ₄ AuCl ₄ , KAuCl ₄ · nH ₂ O, KAu (CN) ₄ , Na ₂ AuCl ₄ , KAuBr ₄ · 2H ₂ O, NaAuBr _{4 and the} like. However, for platinum compounds, chloroplatinic acid, dinitrodiammine platinum, dichlorotetraammine platinum and the like can be mentioned, and for palladium compounds, dinitrodiammine palladium, ammonium chloropalladate and the like can be mentioned. The concentration of the metal compound in the metal compound solution is not particularly limited, but it is preferable to prepare the solution as 1 × 10 ⁻² to 1 × 10 ⁻⁵ mol / L because the generated catalyst particles are hard to aggregate.

As described above, since the catalyst body film 100 of the present embodiment is in the form of a film, all of the catalyst particles contained in the catalyst body film easily come in contact with the gas to be treated, and can maintain excellent catalyst activity. In addition, the catalyst film of the present embodiment can be thicker to form a catalyst film, and a catalyst film having more excellent catalytic activity can be provided.
The porous catalyst membrane of the present embodiment can be decomposed and removed by oxidizing harmful components such as hydrocarbons, carbon monoxide, and ammonia, and the catalyst activity is unlikely to be reduced, and can be used for a long time.

  Next, a gas processing apparatus in which the catalyst membrane 100 of the present embodiment is used will be described. FIG. 2: is the figure which represented typically a part of cross section of the gas processing apparatus 200 of 1st Embodiment. The gas processing apparatus 200 according to the present embodiment uses the plasma generated in the gas processing apparatus 200 and the function of the catalyst film 100 to generate harmful components in the gas to be processed supplied in the direction of arrow A to the gas processing apparatus 200. It is a device that oxidizes and decomposes.

  The gas processing apparatus 200 has a plasma generation unit including an application electrode 11, a ground electrode 12, and a dielectric 13. The application electrode 11 is connected to a (high voltage) power supply 14 which is a power supply unit. The ground electrode 12 and the application electrode 11 are disposed to face each other, and the dielectric 13 is disposed between the ground electrode 12 and the application electrode 11. The dielectric 13 adheres only to the ground electrode 12 and is separated from the application electrode 11. In the gas processing apparatus 200, the application electrode 11, the ground electrode 12, and the dielectric 13 are members / devices (plasma generation units) for generating plasma, and between the application electrode 11 and the ground electrode 12 by the power supply 14. Voltage is applied, and a low temperature plasma reaction layer (a region where plasma exists) is formed between the application electrode 11 and the dielectric 13 by the application electrode 11, the ground electrode 12, and the dielectric 13. . Note that one of the application electrode 11 and the ground electrode 12 is a first electrode, and the other is a second electrode. In addition, even when a plurality of application electrodes 11 and a plurality of ground electrodes 12 are combined in another embodiment, one of the plurality of electrodes of each type is the first electrode, and each of the plurality of electrodes of the other type is It is a second electrode. Further, in the present embodiment, the dielectric 13 is provided only between the ground electrode 12 and the catalyst film 100, but in addition to the space between the ground electrode 12 and the catalyst film 100, the dielectric 13 and the application electrode 11 are provided. It may be provided between the catalyst membrane 100.

  The application electrode 11 is an electrode to which a voltage is applied by the power supply 14. The ground electrode 12 is grounded by the ground line 12a. The application electrode 11, the ground electrode 12, and the dielectric 13 have a breathable structure through which the gas to be treated can pass. Specifically, examples of the structure of the application electrode 11, the ground electrode 12, and the dielectric 13 include a lattice shape, a ridge shape, a porous shape by punching process, an expanded mesh shape, and a honeycomb structure. The structure which combined 2 or more types may be sufficient. The application electrode 11 and the ground electrode 12 may have a needle-like structure. Further, the application electrode 11, the ground electrode 12, and the dielectric 13 may have the same shape or structure among the above-described shapes and structures. In FIG. 2, the application electrode 11 has a large number of small openings such as meshes, and the ground electrode 12 and the dielectric 13 have a large number of small openings such as porous by punching.

  The to-be-processed gas supplied to the plasma generation part from the arrow A direction reaches the low temperature plasma reaction layer formed between the application electrode 11 and the dielectric 13 through the opening formed in the application electrode 11. The gas to be treated that has reached the low temperature plasma reaction layer is either discharged directly to the outside of the plasma generating portion, or outside the plasma generating portion through the opening formed in the dielectric 13 and the opening formed in the ground electrode 12. Discharged into That is, in the plasma generating portion, a flow constituted by the application electrode 11, the opening formed in the ground electrode 12 and the dielectric 13, and the low temperature plasma reaction layer formed between the application electrode 11 and the dielectric 13 A path is formed.

  In the low temperature plasma reaction layer (between the application electrode 11 and the dielectric 13) in the flow path formed in the plasma generation part, the catalyst film 100 in close contact with the dielectric 13 and the application electrode 11 is disposed. . For this reason, the to-be-processed gas which flows through the flow path and reaches the low temperature plasma reaction layer can pass through the catalyst membrane 100 through the pores. Therefore, harmful components in the gas to be treated are oxidized and decomposed by the function of the catalyst film 100 on which the plasma acts.

  As the application electrode 11 and the ground electrode 12 used in the gas treatment apparatus 200, materials that function as electrodes can be used. As a material of the application electrode 11 and the ground electrode 12, for example, a metal such as Cu, Ag, Au, Ni, Cr, Fe, Al, Ti, W, Ta, Mo, or Co, or an alloy thereof can be used.

The dielectric 13 may have the property of being an insulator. As a material of the dielectric 13, for example, ZrO ₂ , γ-Al ₂ O ₃ , α-Al ₂ O ₃ , θ-Al ₂ O ₃ , η-Al ₂ O ₃ , amorphous Al ₂ O ₃ , alumina nitride Ride, mullite, stearite, forsterite, cordierite, magnesium titanate, barium titanate, SiC, Si ₃ N ₄ , Si-SiC, mica, inorganic materials such as glass, polyimide, liquid crystal polymer, PTFE (poly Examples include polymeric materials such as tetra fluoro ethylene, ETFE (ethylene tetra fluoro ethylene), PVF (poly vinyl fluoride), PVDF (poly vinylidene difluoride), polyether imide, and polyamide imide. In view of plasma resistance and heat resistance, inorganic materials are more preferable.

  As described above, when the catalyst film 100 also has a function as a dielectric (for example, when a part of the catalyst film 100 is an insulator), the catalyst film 100 can also be used as a dielectric. Therefore, the dielectric 13 may not be provided. Further, in the gas processing apparatus 200 of the present embodiment, the usage conditions such as the amount of the processing target gas flowing in the flow path and the flow rate are not particularly limited. For example, a blower may be connected to the gas processing apparatus 200, and a predetermined amount of gas to be treated may be sent to the flow path at a predetermined flow rate, or the gas treatment apparatus 200 is left in the gas to be treated, and the gas to be treated is naturally It may only flow into the flow path.

  The power supply 14 is a power supply to which a high voltage can be applied. As the power supply 14, a high voltage power supply such as an AC high voltage or a pulse high voltage, a power supply in which an alternating current or a pulse is superimposed on a DC bias, or the like can be used. Examples of AC high voltage include sine wave AC, rectangular wave AC, triangular wave AC, sawtooth AC and the like. A predetermined voltage may be applied between the application electrode 11 and the ground electrode 12 so that plasma is generated in the discharge space formed by the application electrode 11, the ground electrode 12, and the dielectric 13 by the power supply 14. The voltage applied by the power source 14 fluctuates depending on the concentration of harmful components contained in the gas to be treated, etc., but may be generally 1 to 20 kV, preferably 2 to 10 kV. The type of discharge generated by the power supplied from the power supply 14 for generating plasma is not particularly limited as long as the plasma can be generated. For example, silent discharge, creeping discharge, corona discharge, pulse discharge, etc. I hope there is. Also, two or more of these discharges may be generated in combination to generate plasma.

  Further, the output frequency of the power supply 14 is preferably a high frequency, and specifically, can be 0.5 kHz or more. Furthermore, 0.5 kHz or more and 30 kHz or less are preferable, and more preferably 1 kHz or more and 20 kHz or less. If the frequency is less than 0.5 kHz, the amount of intermediate products and ozone produced may increase, and if it is greater than 30 kHz, the decomposition by oxidation may be suppressed for any harmful component to be treated.

  Although the dielectric 13 is in close contact with the ground electrode 12 in the present embodiment, the present invention is not limited to this. It is sufficient that the plasma can be generated, and the dielectric 13 should be in close contact with at least one of the application electrode 11 and the ground electrode 12. Alternatively, the dielectric 13 may be disposed in close contact with each of the application electrode 11 and the ground electrode 12, and the catalyst film 100 may be provided between the two dielectrics 13. Furthermore, when the catalyst film 100 is formed on the above-described base material, the dielectric 13 can also be used as a base material.

  Next, a gas treatment apparatus 300 of the second embodiment will be described. In the present embodiment, the same reference numerals are used for members having the same functions as the members described in the first embodiment, and the detailed description will be omitted. The differences from the first embodiment are mainly described below.

  FIG. 3: is the figure which represented typically a part of cross section of the gas processing apparatus 300 of 2nd Embodiment. The gas processing apparatus 300 of the present embodiment generates plasma by silent discharge. The gas processing apparatus 300 of the present embodiment has a laminated structure in which two opposing dielectrics 13 are disposed between the application electrode 11 and the ground electrode 12, and each of the dielectrics 13 corresponds to the application electrode 11 and the ground. It is in close contact with the electrode 12.

  The gas processing apparatus 300 forms a low temperature plasma reaction layer between the two dielectrics 13 by applying a voltage between the application electrode 11 and the ground electrode 12 using the high voltage power supply 14. In FIG. 3, the dielectrics 13 are stacked in close contact with both the application electrode 11 and the ground electrode 12, but only one of the dielectrics 13 may be provided.

  In the gas processing apparatus 300 of the present embodiment, the application electrode 11, the ground electrode 12, and the dielectric 13 have a non-air-permeable structure through which the gas to be treated does not pass. For this reason, the gas to be treated supplied to the plasma generation unit from the direction of arrow a in FIG. 3 passes through the low temperature plasma reaction layer formed between the two dielectrics 13 and is discharged to the outside of the plasma generation unit. (Direction of arrow b). That is, in the plasma generating portion, a flow path constituted by a low temperature plasma reaction layer (a region where plasma exists) formed between the two dielectrics 13 is formed. In the flow path formed in the low temperature plasma reaction layer, two opposing catalyst films 100 in close contact with different dielectrics 13 are disposed at a predetermined interval. Therefore, the processing target gas flowing through the low temperature plasma reaction layer can pass through the catalyst film 100 through the mesopores. Therefore, the harmful components in the gas to be treated are oxidized and decomposed by the function of the catalyst film 100 on which the plasma acts, as in the first embodiment. The catalyst film 100 may or may not be in close contact with the dielectric 13. Although depending on the amount of the gas to be treated, if the pressure loss in the flow path is high, the catalyst film 100 should not be in close contact with the dielectric 13. Also in the present embodiment, the catalyst film 100 may be used as the dielectric 13, and the dielectric 13 may also be used as a base on which the catalyst film 100 is formed.

  The gas processing device 300 can easily secure a flow path by having a multilayer structure. Therefore, the amount of gas to be treated can be easily increased, and a large amount of harmful components can be efficiently decomposed. The gas processing apparatus 300 is installed so that the harmful components can be efficiently oxidized and decomposed according to the amount of harmful components to be treated and the use conditions such as the flow velocity. The catalyst film 100 may be a single layer or a plurality of layers, and may be set arbitrarily.

  Next, a gas treatment apparatus 400 according to a third embodiment will be described. In the present embodiment, the same reference numerals are used for members having the same functions as the members described in the first embodiment, and the detailed description will be omitted. The differences from the first embodiment are mainly described below.

  FIG. 4: is the figure which represented typically a part of cross section of the gas processing apparatus 400 of 3rd Embodiment. In the gas processing apparatus 400 of the present embodiment, an application is provided between two opposing ground electrodes 12, two dielectrics 13 disposed between the two ground electrodes 12, and two dielectrics 13. An electrode 11 is provided. The ground electrode 12 and the dielectric 13 are in close contact with each other, and the dielectric 13 and the application electrode 11 are disposed at a predetermined interval. The gas processing apparatus 400 generates plasma between the two dielectrics 13 and the application electrode 11 by applying a voltage between the application electrode 11 and the ground electrode 12 using the high voltage power supply 14. As a result, two plasma reaction layers sandwiching the application electrode 11 can be formed.

  In the gas processing apparatus 400 of the present embodiment, the ground electrode 12 and the dielectric 13 have a non-air-permeable structure through which the process gas does not pass. On the other hand, the application electrode 11 has a plurality of openings, and has a gas-permeable structure through which the gas to be treated passes. For this reason, the gas to be treated supplied to the plasma generating portion from the direction of arrow a in FIG. 3 passes through the low temperature plasma reaction layer while moving through the two plasma reaction layers through the opening formed in the application electrode 11. And are discharged to the outside of the plasma generation unit. That is, in the plasma generating portion, an opening formed in the application electrode 11 and a flow path constituted by two plasma reaction layers are formed.

  A catalyst film 100 in close contact with the application electrode 11 is disposed in each of two low temperature plasma reaction layers (between the two dielectrics 13 and the application electrode 11) in the flow path formed in the plasma generation portion. There is. For this reason, the to-be-processed gas which moves a flow path can pass the catalyst body film | membrane 100 through a pore. Therefore, harmful components in the gas to be treated are oxidized and decomposed by the function of the catalyst film 100 on which the plasma acts.

  Similar to the gas processing apparatus 300 of the second embodiment, the gas processing apparatus 400 has a multilayer structure, which makes it easy to secure the flow path. Therefore, the amount of gas to be treated can be easily increased, and a large amount of harmful components can be efficiently decomposed. The gas processing apparatus 400 is installed so that the harmful components can be efficiently oxidized and decomposed according to the amount of harmful components to be treated and the use conditions such as the flow velocity. The catalyst film 100 may be a single layer or a plurality of layers, and may be set arbitrarily.

  Next, a gas processing apparatus 500 of the fourth embodiment will be described. In the present embodiment, the same reference numerals are used for members having the same functions as the members described in the first embodiment, and the detailed description will be omitted. The differences from the first embodiment are mainly described below.

  FIG. 5: is the figure which represented typically a part of cross section of the gas processing apparatus 500 of 4th Embodiment. The gas processing apparatus 500 of the present embodiment generates plasma by silent discharge to decompose harmful components. In the gas processing apparatus 500 of the present embodiment, the cylindrical application electrode 11, the catalyst film 100, and the dielectric 13 are laminated radially outward in an annual ring shape with the cylindrical ground electrode 12 as a central axis. It has a cylindrical structure.

  In the gas processing apparatus 500, two dielectrics 13 are provided. One dielectric 13 is disposed radially outside the ground electrode 12 and is in close contact with the ground electrode 12. The other dielectric 13 is disposed radially inward of the application electrode 11 and is in close contact with the application electrode 11. The gas processing apparatus 500 can form a low temperature plasma reaction layer by discharge between two dielectrics 13 by applying a voltage between the application electrode 11 and the ground electrode 12 using the high voltage power supply 14 it can. In FIG. 5, the dielectric 13 is in close contact with and laminated on each of the application electrode 11 and the ground electrode 12. However, only one dielectric 13 may be provided.

  In the gas processing apparatus 500 of the present embodiment, the application electrode 11, the ground electrode 12, and the dielectric 13 have a structure that does not allow gas to be treated to pass therethrough. Therefore, the gas to be treated supplied to the plasma generating portion from one of the circular end faces (the direction of the arrow a in FIG. 4) passes through the low temperature plasma reaction layer formed between the two dielectrics 13 It is discharged from the other end face side (arrow b direction in FIG. 4). That is, in the plasma generation portion, a flow path constituted by the low temperature plasma reaction layer formed between the two dielectrics 13 is formed. A catalyst film 100 separated from the two dielectrics 13 is disposed in the flow path formed in the low temperature plasma reaction layer. Therefore, the processing target gas flowing through the low temperature plasma reaction layer can pass through the catalyst film 100 through the mesopores. Therefore, the harmful components in the gas to be treated are oxidized and decomposed by the function of the catalyst film 100 on which the plasma acts, as in the first to third embodiments. In FIG. 5, a space is formed between the catalyst film 100 and the two dielectrics 13. In addition, the catalyst film 100 may be in close contact with one of the dielectrics 13 or may not be in close contact.

  As in the gas processing device 500 of the present embodiment, the annual ring-shaped multilayer structure may be used, and the multilayer structure makes it easy to secure the flow path. Therefore, the amount of gas to be treated can be easily increased, and a large amount of harmful components can be efficiently decomposed. The number of cylindrical annual rings of the catalyst film 100 is such that the gas processing apparatus 500 can efficiently oxidize and decompose the gas to be treated according to the amount of harmful components to be treated and the use conditions such as the flow rate. It is possible to optionally set one or more pieces.

Here, in the gas processing apparatuses according to the first to fourth embodiments, when the harmful component contained in the gas to be treated is treated, the harmful component is contained in a state where a voltage is applied to the application electrode 11 by the power supply 14. The gas to be treated is supplied to the flow path. As a result, harmful components in the gas to be treated that flow in the flow path and reach the pores are oxidized and decomposed at normal temperature without being heated by the catalyst film 100. Furthermore, harmful components in the gas to be treated may be oxidized and decomposed by plasma.
Moreover, if the catalyst film 100 alone is in contact with harmful components, the surface of the catalyst film 100 (more specifically, the catalyst particles in the pores opening on the surface) is poisoned and the catalyst activity is lost. And may form reaction intermediates such as formaldehyde. In the gas processing apparatus of the first to fourth embodiments, the surface of the catalyst film 100 is cleaned by using plasma together, and the catalytic activity is maintained for a long time. Furthermore, in the gas treatment devices of the first to fourth embodiments, the amount of reaction intermediates produced is also very small, and the decomposition by the oxidation of harmful components can be maintained for a longer period of time.

  Further, in the gas processing apparatus 200 of the first embodiment, the application electrode 11 is described as being disposed on the upstream side in the gas flow direction. However, the present invention is not limited thereto, and gas may flow from the ground electrode 12 side.

  The gas processing apparatuses according to the first to fourth embodiments described above can suppress the formation of reaction intermediates by combining the catalyst film 100 capable of maintaining the catalytic activity and maintaining the catalytic activity, and plasma. At the same time, even if the catalyst film 100 (specifically, catalyst particles) is poisoned in the process of decomposition treatment, the catalyst film 100 is cleaned by plasma, so the catalyst activity of the catalyst film 100 is maintained for a longer period of time can do. Therefore, according to the gas processing apparatuses of the first to fourth embodiments, it is possible to realize a gas processing apparatus capable of oxidizing and decomposing harmful components for a long time.

  Next, the present invention will be more specifically described by way of examples. However, the present invention is not limited to only these examples.

Example 1
(Glass substrate on which zirconium oxide particle-containing zirconium oxide film is immobilized)
1 mL of ethanol was added to 0.2 g of surfactant (P123) and stirred for 20 minutes to obtain solution A.
Furthermore, 0.286 mL of acetic acid, 0.1 mL of pure water and 0.5 g of zirconium oxide particles (manufactured by Shin Nippon Electric Co., Ltd.) are added to 0.58 g of zirconium (IV) propoxide (Zr (OPr) 4) The mixture was stirred for 10 minutes to obtain solution B.
After adding solution A to solution B, 0.093 mL of hydrochloric acid was added, and the mixture was stirred for 1 hour to obtain a precursor solution of a porous zirconium oxide film.
Thereafter, using a precursor solution of a porous zirconium oxide film, a film was formed on a glass substrate using a spin coater at a rotational speed of 3000 rpm. The formed glass substrate was placed in a petri dish, and allowed to stand for 2 hours in an environment (freezer) at -20 ° C and 20% RH. After removing from the freezer and returning to normal temperature, the lid of the petri dish was opened to take out the glass substrate. It baked at 450 degreeC for 4 hours with an electric furnace, and obtained the glass substrate which fixed the porous zirconium oxide film | membrane. The temperature was raised and lowered at 1 ° C./min.
The aqueous solution of chloroauric acid having a predetermined concentration was placed in a beaker and heated to 70 ° C. with a water bath. The pH was adjusted to 7 by slow addition of 0.1 M aqueous sodium hydroxide solution. The chloroauric acid aqueous solution was cooled to normal temperature, and the glass substrate on which the mesoporous zirconium oxide film was immobilized was immersed and degassed for about 15 minutes under reduced pressure. The mixture was heated again to 70 ° C. with a water bath and stirred for 1 hour after reaching 70 ° C. The glass substrate on which the porous zirconium oxide film was immobilized was taken out and washed five times with pure water, and excess water was removed with a rag. The glass substrate was sintered at 300 ° C. for 2 hours in an electric furnace to obtain an Au-supported porous zirconium oxide film immobilized thereon.
When the film thickness and mass of the Au-supporting porous zirconium oxide film were measured, the film thickness was 890 nm and the film mass with respect to the substrate area was 0.587 mg / cm ² , and the zirconium oxide particles and the porous body (the catalyst particles were removed The mass ratio of the medium area, hereinafter the same) was 77:23. Further, when measured by atomic absorption, the supported amount of Au relative to the substrate area was 0.063 g / cm ² . The glass substrate on which the Au-supporting porous zirconium oxide film is immobilized is measured by the BET method, and the specific surface area, pore volume and pore diameter of the porous zirconia oxide film are 148 m ^{2 /} g and 0.38 g / cm, respectively. ³ , 3.28 nm. Moreover, when the particle size of Au was observed by TEM, it was 2.5 nm.

Example 2
(Glass substrate on which titanium oxide particle-containing zirconium oxide film is immobilized)
A glass substrate on which an Au-supporting porous zirconium oxide film was immobilized was obtained in the same manner as in Example 1 except that the zirconium oxide particles were changed to titanium oxide particles (manufactured by Nippon Aerosil Co., Ltd.).
When the film thickness and mass of the Au-supporting porous zirconium oxide film were measured, the film thickness was 1614 nm, the film mass to the substrate area was 0.830 mg / cm ² , and the mass ratio of titanium oxide particles to the porous body was 77:23. Met. Further, when measured by atomic absorption, the amount of Au supported on the substrate area was 0.102 g / cm ² . The glass substrate on which the Au-supported mesoporous zirconium oxide film is immobilized is measured by BET method, and the specific surface area, pore volume, and pore diameter of the mesoporous zirconium oxide film are 148 m ^{2 /} g and 0.38 g / cm ³ , respectively. It was 3.28 nm. Moreover, when the particle size of Au was observed by TEM, it was 2.5 nm.

[Example 3]
(Glass substrate on which zirconium oxide particle-containing zirconium oxide film is immobilized)
A glass substrate on which an Au-supported porous zirconium oxide film was immobilized was obtained in the same manner as in Example 1 except that the firing temperature was changed to 350 ° C.
When the film thickness and mass of the Au-supporting porous zirconium oxide film were measured, the film thickness was 1236 nm, the film mass with respect to the substrate area was 0.823 mg / cm ² , and the volume ratio of zirconium oxide particles to the porous body was 77:23 Met. Further, when measured by atomic absorption, the amount of Au supported on the substrate area was 0.095 g / cm ² . The glass substrate on which the Au-supporting porous zirconium oxide film is immobilized is measured by the BET method, and the specific surface area, pore volume, and pore diameter of the porous zirconium oxide film are 220 m ^{2 /} g and 0.45 g / cm, respectively. ³ , 3.28 nm. Moreover, when the particle size of Au was observed by TEM, it was 2.5 nm.

Example 4
(Glass substrate on which a zirconium oxide film containing cerium oxide particles is immobilized (1))
A glass substrate on which an Au-supporting porous zirconium oxide film was immobilized was obtained in the same manner as in Example 1 except that 0.5 g of zirconium oxide particles was changed to 1.0 g of cerium oxide particles (manufactured by Shin-Etsu Chemical Co., Ltd.) .
When the film thickness and mass of the Au-supporting porous zirconium oxide film were measured, the film thickness was 1790 nm, the film mass with respect to the substrate area was 1.532 mg / cm ² , and the mass ratio of the cerium oxide particles to the porous body was 87:33 Met. Further, when measured by atomic absorption, the supported amount of Au relative to the substrate area was 0.272 g / cm ² . The glass substrate on which the Au-supporting porous zirconium oxide film is immobilized is measured by BET method, and the specific surface area, pore volume and pore diameter of the porous zirconium oxide film are 148 m ^{2 /} g and 0.38 g / cm, respectively. ³ , 3.28 nm. Moreover, when the particle size of Au was observed by TEM, it was 2.5 nm.

[Example 5]
(Glass substrate on which a zirconium oxide film containing cerium oxide particles is immobilized (2))
A glass substrate on which an Au-supporting porous zirconium oxide film was immobilized was obtained in the same manner as in Example 1 except that the zirconium oxide particles were changed to cerium oxide particles (manufactured by Shin-Etsu Chemical Co., Ltd.).
When the film thickness and mass of the Au-supporting porous zirconium oxide film were measured, the film thickness was 834 nm, the film mass to the substrate area was 0.749 mg / cm ² , and the mass ratio of the cerium oxide particles to the porous body was 77:13. Met. Further, when measured by atomic absorption, the supported amount of Au relative to the substrate area was 0.173 g / cm ² . The glass substrate on which the Au-supporting porous zirconium oxide film is immobilized is measured by BET method, and the specific surface area, pore volume and pore diameter of the porous zirconium oxide film are 148 m ^{2 /} g and 0.38 g / cm, respectively. ³ , 3.28 nm. Moreover, when the particle size of Au was observed by TEM, it was 2.5 nm.

[Example 6]
(Glass substrate on which a zirconium oxide film containing cerium oxide particles is immobilized (3))
A glass substrate on which an Au-supporting porous zirconium oxide film was immobilized was obtained in the same manner as in Example 1 except that 0.5 g of zirconium oxide particles was changed to 0.3 g of cerium oxide particles (manufactured by Shin-Etsu Chemical Co., Ltd.) .
When the film thickness and mass of the Au-supporting porous zirconium oxide film were measured, the film thickness was 571 nm, the film mass relative to the substrate area was 0.387 mg / cm ² , and the mass ratio of the cerium oxide particles to the porous body was 67:23 Met. Moreover, when measured by atomic absorption, the supported amount of Au with respect to the substrate area was 0.075 g / cm ² . The glass substrate on which the Au-supporting porous zirconium oxide film is immobilized is measured by BET method, and the specific surface area, pore volume and pore diameter of the porous zirconium oxide film are 148 m ^{2 /} g and 0.38 g / cm, respectively. ³ , 3.28 nm. Moreover, when the particle size of Au was observed by TEM, it was 2.5 nm.

Comparative Example 1
A glass substrate on which an Au-supporting porous zirconium oxide film was immobilized was obtained by the same method as in Example 1 except that a precursor solution was prepared without using zirconium oxide particles.
When the film thickness and mass of the Au-supporting porous zirconium oxide film were measured, the film thickness was 109 nm, and the film mass with respect to the substrate area was 0.082 mg / cm ² . In addition, when measured by atomic absorption, the amount of Au supported on the substrate area was 0.018 mg / cm ² . The glass substrate on which the Au-supported zirconium oxide film is immobilized is measured by BET method, and the specific surface area, pore volume and pore diameter of the porous zirconia oxide film are 148 m ^{2 /} g and 0.38 g / cm ³ , respectively. It was 3.28 nm. Moreover, when the particle size of Au was observed by TEM, it was 2.5 nm.

Comparative Example 2
A commercially available zirconium oxide fine particle (PCD, manufactured by Nippon Denko Corporation) was dispersed as 10.0% by mass in methanol as inorganic fine particles, and the pH was adjusted to 4.0 with hydrochloric acid, and then pulverized and dispersed to an average particle diameter of 20 nm by a bead mill. . Thereafter, using the obtained dispersion, a film was formed on a glass substrate at a rotational speed of 3000 rpm using a spin coater, to obtain a glass substrate on which only zirconium oxide fine particles were immobilized. In the same manner as in Example 1, a glass substrate on which the Au-supported zirconium oxide fine particle film was immobilized was obtained. In addition, since this film | membrane was comprised only with microparticles | fine-particles, adhesiveness with a glass substrate was bad, and the film fell off when an impact etc. were added.
When the film thickness and mass of the Au-supported zirconium oxide film were measured, the film thickness was 156 nm, and the film mass with respect to the substrate area was 0.106 mg / cm ² . Further, when measured by atomic absorption, the supported amount of Au relative to the substrate area was 0.014 mg / cm ² . When a glass substrate on which an Au-supported zirconium oxide film is immobilized is measured by BET method, it is confirmed that the specific surface area of the zirconium oxide film is 10 m ² / g and this zirconium oxide film does not have a mesoporous structure It was done. Moreover, when the particle size of Au was observed by TEM, it was 2.5 nm.
The characteristics of the catalyst membranes obtained in Examples 1 to 6 and Comparative Examples 1 and 2 are shown in Table 1.

(CO removal test)
The carbon monoxide oxidation (CO) was used as a harmful | toxic component, and the CO oxidation reaction of the catalyst body film of the Example and the comparative example was evaluated. Specifically, a test apparatus in which glass substrates on which the catalyst films of the Examples and Comparative Examples are immobilized is installed in a flow channel so as to have a predetermined flow channel width and height (width 5 cm, height 1 mm). Prepared. Carbon monoxide (concentration 1,000 ppm) and air were mixed to prepare a gas to be treated, and the gas to be treated was supplied to the flow path while the flow rate was controlled by a mass flow controller, and a CO removal test was performed.

In the analysis of the gas to be treated before treatment and the gas to be treated after treatment by the test apparatus, an infrared spectrophotometer (FTIR-6000, manufactured by JASCO Corporation) loaded with a gas cell with a long light path (2.5 m) was used. The reaction conditions were: carbon monoxide concentration 1,000 ppm, oxygen concentration 20%, relative humidity 50%, gas flow rate 0.1 L / min, catalyst size 25 cm ² , reaction temperature room temperature, treatment time 1 hour.

The concentration of CO in the gas to be treated (hereinafter also referred to as “initial CO concentration”) before being supplied to the test apparatus using the infrared spectrophotometer described above, and the gas to be treated after being treated for 1 hour in the test device The concentration of CO in the medium (hereinafter, also referred to as “the concentration of CO after reaction”) was measured, and the CO removal rate was calculated using the following equation.
CO removal rate (%) = {(initial CO concentration-post-reaction CO concentration) / initial CO concentration} × 100

(Test Example 1)
The glass substrate obtained in Example 1 was placed in a test apparatus, and a CO removal test was performed.
(Test Example 2)
The glass substrate obtained in Example 2 was placed in a test apparatus, and the CO removal test was performed in the same manner as in Test Example 1.
(Test Example 3)
The glass substrate obtained in Example 3 was placed in a test apparatus, and the CO removal test was performed in the same manner as in Test Example 1.
(Test Example 4)
The glass substrate obtained in Example 4 was placed in a test apparatus, and the CO removal test was performed in the same manner as in Test Example 1.
Test Example 5
The glass substrate obtained in Example 5 was placed in a test apparatus, and the CO removal test was performed in the same manner as in Test Example 1.
(Test Example 6)
The glass substrate obtained in Comparative Example 1 was placed in a test apparatus, and the CO removal test was performed in the same manner as in Test Example 1.
Test Example 7
The glass substrate obtained in Comparative Example 2 was placed in a test apparatus, and the CO removal test was performed in the same manner as in Test Example 1.

  The CO removal rates in Test Examples 1 to 7 are shown in Table 2.

As shown in Table 1, compared with the catalyst films of Comparative Examples 1 and 2, the catalyst films of Examples 1 to 6 have a large film mass per unit area and a large amount of gold particles supported, and carry a large number of catalyst particles. I was able to confirm that I was doing.
In addition, as shown in Table 2, in Examples 1 to 5 in which the catalyst films of Examples 1 to 5 were used, the CO removal rate was 30% or more in all cases. 6 to 7 had a CO removal rate of 4% or less. From these results, it was confirmed that the porous catalyst membranes of Examples 1 to 5 have superior catalytic activity as compared with the catalyst membranes of Comparative Examples 1 and 2. The above results show the effectiveness of the present invention.

Claims (17)

A membrane support region configured to be one or more selected from the group consisting of solid particles, fibers, an aggregate of fibers or solid particles, and a monolithic structure, and which assists in maintaining the shape of the membrane;
A catalyst body region which is porous adjacent to the membrane support region in the membrane and has pores opened at the membrane surface, and in which the catalyst particles containing noble metal and / or noble metal oxide are supported in the pores A porous catalyst membrane characterized by comprising:   The porous catalyst membrane according to claim 1, wherein the membrane support region is composed of a metal oxide and / or a silicon oxide. The metal oxide and / or silicon oxide is composed of at least one or more of SiO ₂ , Al ₂ O _3, TiO ₂ , Fe ₂ O ₃ , ZrO ₂ , and CeO _2. Item 3. The porous catalyst membrane according to Item 1 and 2.   The porous catalyst membrane according to any one of claims 1 to 3, wherein the membrane support region is composed of solid particles and / or solid particle aggregates.   5. The porous catalyst membrane according to claim 4, wherein the membrane support region is constituted by a solid particle aggregate, and the solid particle aggregate is a continuous structure in which the particles are sintered. .   The film support region according to any one of claims 1 to 5, wherein at least a part of the membrane support region has pores, and the pores support a catalyst particle containing a noble metal and / or a noble metal oxide. The porous catalyst body membrane as described in 1). The porous catalyst according to any one of claims 1 to 6, wherein a catalyst particle loading amount of the porous catalyst membrane is 0.050 mg / cm ² or more and 1.000 mg / cm ² or less. Medium membrane.   The membrane support region according to any one of claims 1 to 7, wherein the mass ratio is 60% or more and 95% or less with respect to the total of the support region excluding the catalyst particles and the catalyst region. The porous catalyst body membrane described in one.   9. The method according to any one of claims 1 to 8, wherein the catalyst particles are particles containing a substance selected from one or more selected from the group consisting of gold, platinum, palladium and oxides thereof. Porous catalyst membrane. The porous body in the catalyst body region contains a metal oxide selected from the group consisting of SiO ₂ , Al ₂ O ₃ , TiO ₂ , Fe ₂ O ₃ , ZrO ₂ and CeO _2. The porous catalyst membrane according to any one of claims 1 to 9, characterized in that   The porous catalyst membrane according to any one of claims 1 to 10, wherein the particle size of the catalyst particles is 2 nm or more and 9 nm or less.   The porous catalyst body membrane according to any one of claims 1 to 11, wherein a loading amount of the catalyst particles is 30% by mass or more and 70% by mass or less with respect to 100% by mass of the catalyst body region. .   The porous catalyst membrane according to any one of claims 1 to 12, wherein the catalyst region has mesopores.   The porous catalyst membrane according to claim 13, wherein the average pore diameter of the mesopores measured by the BET method is 3 nm or more and 10 nm or less.   The porous catalyst membrane according to any one of claims 1 to 14, wherein the porous catalyst membrane is an oxidation reaction catalyst of carbon monoxide or an organic compound. A film-like body having pores obtained by applying a solution containing solid particles, a hydrolyzate of alkoxysilane or metal alkoxide, and a surfactant to a substrate followed by calcination, a noble metal contained in the oxidation catalyst particle, and And / or contacting with a solution in which the metal compound corresponding to the noble metal oxide is dissolved,
The porous catalyst membrane according to any one of claims 1 to 15, comprising forming an oxidation catalyst particle in pores of the membrane by calcination and / or reduction treatment. Manufacturing method. At least a first electrode, a second electrode, and a dielectric disposed between the first electrode and the second electrode, and between the first electrode and the second electrode A plasma generation unit that generates a plasma by applying a voltage to generate a discharge;
A flow path through which a gas to be treated flows, which is formed in a region where the plasma generated by the plasma generation unit is present;
A gas processing apparatus comprising: the porous catalyst membrane according to any one of claims 1 to 15 disposed in the flow path.