JP2018134615A - Organic gas reduction device and organic gas reduction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel technique for reducing the concentration of organic gas by oxidizing the organic gas in gas to be treated.SOLUTION: Provided is an organic gas reduction device including: a gas permeable member having a surface on which a film-like substrate with mesopores is formed; and a gas supply part which supplies gas to be treated to the film-like substrate. In the mesopores of the film-like substrate, oxidation catalyst particles are carried which contain one or two kinds or more substances selected from a group consisting of platinum, a unit body of palladium, and their oxides. In the organic gas reduction device, organic gas in the gas to be treated supplied to the film-like substrate is oxidized.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus and method for oxidizing an organic gas component in a gas to be treated, particularly in the atmosphere.

Since exhaust gas generated from internal combustion engines such as automobiles and factories contains trace amounts of harmful components such as carbon monoxide, they are released into the atmosphere after they are removed using removal means. In addition, in a closed storage room or the like, a trace amount of malodorous substances may be produced and a mold odor may be generated, and various removal means are applied.
In addition, agricultural products release ethylene having a ripening action, and the aging of the product progresses. Therefore, keeping the temperature and humidity constant and reducing the ethylene gas concentration are said to be effective for maintaining the freshness for a long time.

  Methods for removing organic trace components in the atmosphere include adsorption on an adsorbent such as activated carbon, radicals by a plasma generator, and decomposition and removal methods using active species such as ozone. However, in the adsorption treatment with the adsorbent, there is an upper limit to the amount of adsorbed harmful gas by the adsorbent, and it is necessary to periodically exchange the adsorbent. A treatment method using active species such as plasma is difficult to use because there is concern about apparent changes such as decolorization in storage of agricultural products.

  In the method of decomposing and removing organic components, in addition to the method of using the physically generated active species as described above, a method of oxidative decomposition using a catalyst is also widely used and applied to a freshness maintaining device. (Patent Document 1). In order to increase the contact area of the oxidation catalyst body, a structure in which an active substance (catalyst particle) is supported on a carrier that is an inorganic particle is used (Patent Documents 1 and 2). A catalyst body in which catalyst particles are supported in the pores of an inorganic mesoporous carrier having cylindrical mesopores has also been developed. Compared with a catalyst body in which catalyst particles are supported on the outer surface of inorganic particles, A catalyst body having a large specific surface area and high activity has been obtained (Patent Documents 3 and 4). In addition, a freshness maintaining apparatus that decomposes ethylene in the air using a photocatalyst has been disclosed (Patent Document 5).

Japanese Patent Laid-Open No. 2006-090088 Japanese Patent Laid-Open No. 2003-080077 JP 2004-283770 A JP 2007-326094 A JP 2007-097528 A

However, the catalyst body in which the oxidation catalyst particles are supported on the above-described cylindrical mesoporous support has a problem that although the initial catalytic activity is high, the catalytic activity decreases with use. The cause is not clearly understood, but the moisture in the atmosphere is adsorbed in the pores, so that the contact between the catalyst particles and the gas to be treated is hindered, and the decomposition reaction of harmful components does not proceed, or the pores May be sealed with adsorbed water, and the flow of the gas to be treated into the pores itself may be hindered. In order to maintain freshness, a low humidity and a high humidity environment with a relative humidity of 80% or more may be used. Under these conditions, the catalytic activity is further reduced.
In addition, in a freshness maintaining apparatus using a photocatalyst, ultraviolet light or visible light is required for the catalyst to act, but since a storage in storage is generally not lit, the apparatus is not equipped with a catalyst. Illumination is required, the structure is complicated, and extra power is required for illumination.

  An object of this invention is to provide the novel technique which reduces the organic gas density | concentration by oxidizing the organic gas in to-be-processed gas.

The gist of the present invention is as follows.
[1] A member having air permeability and having a membranous support having a mesopore formed on a surface thereof, and a gas supply unit that supplies a gas to be processed to the membranous support,
In the mesopores of the membrane-like support, oxidation catalyst particles containing one or more substances selected from the group consisting of simple substances of platinum and palladium and oxides thereof are supported. An organic gas reducing device that oxidizes an organic gas in a supplied gas to be treated.
[2] The organic gas reducing device according to [1], wherein the organic gas contained in the gas to be treated is ethylene.
[3] The gas supply unit has a blower mechanism that blows non-processed gas to the film-like support, and a space velocity of blown air by the blower mechanism is 10,000 / h or more and 150,000 / h or less. The organic gas reduction device according to [1] or [2].
[4] From [1], further comprising a member supporting a compound having at least one of antibacterial property, antifungal property, and antiviral property disposed on the upstream side in the air flow direction of the member. [3] The organic gas reducing device according to any one of [3].
[5] The organic gas reduction device according to any one of [1] to [4], wherein the film-like support has a thickness of 50 nm to 1000 nm.
[6] The organic gas reduction device according to any one of [1] to [5], wherein the film-like support is made of SiO ₂ .
[7] The organic gas reduction device according to any one of [1] to [6], wherein an average pore diameter of the mesopores measured by a BET method is 2 nm or more and 10 nm or less.
[8] The organic gas reduction device according to any one of [1] to [7], wherein an average particle diameter of the oxidation catalyst particles is 1 nm or more and 10 nm or less.
[9] A membranous membrane having mesopores and carrying oxidation catalyst particles containing a substance selected from the group consisting of platinum and palladium alone and their oxides in the mesopores An organic gas reduction method comprising: supplying a gas to be treated to a support and diffusing the gas to reduce an organic gas concentration contained in the gas.

  ADVANTAGE OF THE INVENTION According to this invention, the novel technique which oxidizes the organic gas in to-be-processed gas and reduces an organic gas density | concentration can be provided.

It is a figure which shows the outline | summary of 1 aspect of the organic gas reduction apparatus of this invention. It is a figure which shows the outline | summary of 1 aspect of the member which has the film-form support body by which the oxidation catalyst particle with which the organic gas reduction apparatus of this invention is equipped was carry | supported. It is a figure which shows the outline | summary of the other aspect of the member which has the film-form support body by which the oxidation catalyst particle with which the organic gas reduction apparatus of this invention is equipped was carry | supported. It is a figure which shows the outline | summary of the other aspect of the organic gas reduction apparatus of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a diagram showing an outline of the organic gas reduction device of the present embodiment. 2 and 3 show oxidation catalyst particles containing a substance selected from the group consisting of platinum and palladium alone and their oxides according to the present embodiment (hereinafter also referred to simply as oxidation catalyst particles). It is a figure which shows the outline | summary of the member which has a membrane-like support body with which it was supported. In the drawing, solid arrows indicate the direction of air movement, and broken arrows indicate the diffusion of air in the oxidation catalyst layer 33.
The organic gas reduction device 100 of the present embodiment is a device that can be used to oxidize a trace amount of organic gas in the atmosphere or the like to provide a good atmospheric state for growth of fruits and vegetables, for example, and has air permeability. And a member 30 having a membranous support 34 having mesopores 37 formed on the surface thereof, and a gas supply unit 10 for supplying a gas to be processed to the membranous support 34. Oxidation catalyst particles are carried in the holes 37 and oxidize the organic gas in the gas to be treated supplied to the membrane-like support 34. In the following description, the membrane support 34 on which the oxidation catalyst particles are supported is also referred to as an oxidation catalyst layer 33. When the gas to be treated is supplied to the oxidation catalyst layer 33 by the gas supply unit 10 and diffused and penetrated, the organic gas component contained in the non-treatment gas is oxidized by the oxidation catalyst particles in the oxidation catalyst layer 33.
According to the organic gas reduction device 100 of the present embodiment, the concentration of the organic gas such as ethylene can be reduced to 0.1 ppm or less, depending on the volume of the oxidation catalyst layer 33 and the amount of supported oxidation catalyst particles. it can.

First, the oxidation catalyst layer 33 will be described.
The oxidation catalyst layer 33 of the present embodiment is formed on the surface of the base material 31. Specifically, in a state where the air permeability is maintained on the surface facing the ventilation portion 35 of the base material 31 having a ventable shape such as a filter shape or a mesh shape (specifically, the ventilation portion 35 of the base material 35). It is formed into a film shape (with air permeability maintained). The base material 31 may be a plate-like, sheet-like, or porous block body as long as it has a structure that allows gas to pass therethrough. As a porous block body, a member having a honeycomb-like void has a large surface area and good air permeability, and is preferable as the substrate.

  Since the oxidation catalyst layer 33 of the present embodiment is in the form of a film, it does not take an agglomerated form like a powder. Therefore, the distance from the mesopores where the oxidation catalyst particles are present to the gas flow of the gas to be treated is It is shorter than other shapes of mesoporous catalyst bodies. Therefore, when moisture in the gas is adsorbed in the mesopores 37 of the oxidation catalyst layer 33 of the embodiment, a concentration gradient to the gas flow to be treated is generated, and the re-diffusion of the adsorbed water to the air flow proceeds. As a result There is an effect that adsorbed water is suppressed to a constant amount. On the other hand, the conventional powdery mesoporous catalyst body has a relatively long distance from the mesopores inside the powder to the air current, and is particularly difficult to desorb moisture adsorbed inside the powder. It is assumed that the catalytic activity of the oxidation catalyst in the mesopores is reduced due to the above.

  The film thickness of the oxidation catalyst layer 33 formed on the substrate 31 is desirably 50 nm or more and 1000 nm or less. If the thickness is less than 50 nm, the absolute amount of the oxidation catalyst is reduced, so that it is difficult to sufficiently oxidize the organic gas component in the gas to be treated as compared with the case where the oxidation catalyst is within the range. If it is larger than 1000 nm, the moisture adsorbed in the mesopores 37 existing at a position away from the gas to be treated is difficult to be re-released, so the amount of moisture adsorbed in the pores increases and the oxidation catalyst particles are inhibited from acting. The catalytic efficiency of the oxidation catalyst layer is reduced as compared with the case where it is within the range. In addition, the film thickness of the oxidation catalyst body layer 33 of this embodiment can be measured by observing the cross section of the film with a TEM and measuring the size of the cross-sectional image.

  The oxidation catalyst layer 33 of the present embodiment can treat organic gas, which is an organic component in the gas to be treated, into carbon dioxide, water, or the like by an oxidation reaction and discharge it into the atmosphere. Gases that can be treated in the oxidation catalyst layer 33 of the present embodiment are not particularly limited. However, compounds emitted from plants such as agricultural products and flower buds, automobile interior materials, residential building materials / interior materials, home appliance housings, Substances that volatilize from materials such as members and substances that volatilize from organic solvents such as paints, adhesives, and cleaning agents. Specifically, hydrocarbons such as methane, ethane, propane, butane, ethylene, propylene, isoprene, benzene, xylene, toluene, ethylbenzene, styrene, α-farnesene, β-farnesene, methanol, ethanol, propane-1- All, butan-1-ol, pentan-1-ol, hexane-1-ol, heptan-1-ol, octan-1-ol, trans-2-hexenol, cis-2-hexenol, trans-3-hexenol, Alcohols such as cis-3-hexenol, linalool, benzyl alcohol, formaldehyde, acetaldehyde, propionaldehyde, butanal, pentanal, nonanal, benzaldehyde, hexanal, trans-2-hexenal, cis-2-hexa Aldehydes such as nal, trans-2-octenal, trans-2-nonenal, cis-2-nonenal, trans, cis-2,6-nonadienal, trans, cis-2,4-decadienal, acetone, ethylmethyl Ketones such as ketone, diethyl ketone, methyl isobutyl ketone, cyclohexanone, acetophenone, methyl formate, ethyl acetate, pentyl acetate, isopentyl acetate, octyl acetate, hexyl acetate, benzyl acetate, methyl butyrate, ethyl butyrate, pentyl butyrate, methyl salicylate, Ethyl caproate Pentyl valerate, ethyl-2-methylpropanoate, ethylbutanoate, methyl-2-methylbutanoate, ethyl-2-methylbutanoate, ethyl-3-methylbutanoate, methyl-3 -Hydroxybutano , Methylhexanoate, ethylhexanoate, hexylhexanoate, methyl-3-hydroxyhexanoate, octylhexanoate, ethyloctanoate, methyl-3-hydroxyoctanoate, ethyl nicotinate, Esters such as γ-hexalactone, γ-octalactone, δ-octalactone, γ-decalactone, δ-decalactone, γ-dodecalactone, δ-dodecalactone, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, capron Examples thereof include carboxylic acids such as acid, enanthic acid, caprylic acid, 2-methylpropanoic acid and 2-methylbutanoic acid, terpenes such as trans-nerolidol, cis-nerolidol and farnesol, and phenols such as eugenol and vanillin. The

The membranous support 34 that is a component of the oxidation catalyst layer 33 of the present embodiment has pores that are mesopores. In this specification, a mesopore refers to a pore having an average diameter of 2 nm or more and 50 nm or less by BET method in which an opening on one surface communicates with another opening on the same or different surface.
The shape of the meso-hole 37 and the positional relationship between the openings are not particularly limited. For example, even in a cylinder shape in which the upper surface and the lower surface of the membrane-like support 34 communicate with each other in a straight line, the meso-hole is branched inside the support 34. A so-called communication structure connected to other meso holes may be used. Since more openings are connected in the communication structure, even if moisture adheres to the inside of the support 34, the air permeability is not easily lost. Therefore, the communication structure is more preferable.

  Here, it is preferable that the average diameter of the mesopores 37 by the BET method is 2 nm or more and 10 nm or less because the particle diameter of the supported oxidation catalyst particles is also within the range and a more highly active catalyst body can be obtained. Note that the diameter of the pores of the support according to the present embodiment is a value calculated using an automatic specific surface area / pore distribution measuring device based on the BET method based on JIS-Z-8831.

Further, if the average particle diameter of the oxidation catalyst particles is 10 nm or less (more preferably 1 nm or more and 10 nm or less, and even more preferably 1 nm or more and 6 nm or less), the specific surface area of the oxidation catalyst particles is increased and the catalytic activity is dramatically improved. And since the oxidation efficiency of the organic gas in to-be-processed gas increases further, it is preferable.
The average particle diameter of the oxidation catalyst particles can be obtained as an average value obtained by calculating individual particle sizes in a transmission electron microscope (TEM) image photograph.

  These oxidation catalyst particles are preferably supported by 0.1 to 20% by mass with respect to the oxidation catalyst layer 33, and more preferably 0.5 to 10% by mass. When the amount is more than 20% by mass, the oxidation catalyst particles are likely to aggregate with each other, and the catalytic activity is reduced as compared with the case where the oxidation catalyst particles are within the range. It is not preferable because sufficient catalytic activity cannot be obtained.

  Note that the oxidation catalyst layer 33 of the present embodiment may include promoter particles and various metal elements in addition to the oxidation catalyst particles, and is not particularly limited. Specifically, the catalyst may be a mixture of cocatalyst particles obtained by combining the cocatalyst and oxidation catalyst particles and oxidation catalyst fine particles, or a composite catalyst composed of composite particles obtained by combining various metal elements with catalyst particles. When the oxidation catalyst particles are used alone or when a promoter is mixed with the oxidation catalyst particles, the oxidation catalyst particles may be within the above-mentioned size range. Examples of the metal particles (nanoparticles) other than the catalyst particles used in the promoter or composite catalyst include noble metals other than Pt and Pd and oxides thereof, base metals and oxides thereof. Two or more kinds of these noble metals and oxides thereof, base metals and oxides thereof may be mixed and supported on the inner surface of the membrane-like support pore.

  The membranous support 34 according to the present embodiment may have any mesopores 37 and can support the oxidation catalyst particles in the mesopores. However, the mesopores may be formed using a template compound. In consideration of the fact that it may be produced including a step of forming 37 and removing the compound by heating, it is preferable that the material does not deteriorate at a heating temperature or higher.

Examples of the metal oxide constituting the film support 34 include γ-Al ₂ O ₃ , α-Al ₂ O ₃ , θ-Al ₂ O ₃ , η-Al ₂ O ₃ , and amorphous Al ₂ O _3. , TiO ₂ , ZrO ₂ , SnO ₂ , SiO ₂ , MgO, ZnO ₂ , Bi 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 Examples thereof include single inorganic oxides such as ₂ O ₃ , In ₂ O ₃ , PbO, and ThO ₂ . 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 film-like support 34 is composed of _{-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 You may do it. 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, 0.05 ≦ δ ≦ 0.15.

What is necessary is just to select the material of the film-form support body 34 according to various environmental conditions in which the organic gas reduction apparatus 100 of this embodiment is used. SiO ₂ is more desirable because it can support the oxidation catalyst particles more firmly and can adhere more strongly to the base material 31.

The oxidation catalyst layer 33 of the present embodiment can be formed on the substrate 31 as described above. It is preferable to form the catalyst body film 33 of the present embodiment on the substrate 31 because the thickness of the oxidation catalyst layer 33 of the present embodiment can be more easily reduced. The shape of the base material 31 is not particularly limited as long as it has air permeability. For example, the base material 31 has a sheet-like shape in which a large number of through holes are formed by punching, a fiber shape, a cloth shape, a mesh shape, a woven fabric, It can be set as the fiber structure (filter shape) comprised from a net | network thing, a nonwoven fabric, etc. In addition, various shapes and sizes suitable for the purpose of use can be used as appropriate.
By using the base material 31, the film-like shape of the support 34 can be easily maintained.

  Since the base material 31 may be heated when the oxidation catalyst layer 33 is formed, it is desirable to use a heat-resistant material that can 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 glass are more preferable.

  Metal materials used for the base material 31 include refractory metals such as tungsten, molybdenum, tantalum, niobium, TZM (Titanium Zirconium Molybdenum), W-Re (tungsten-rhenium), noble metals such as silver and ruthenium, and their Alloys or oxides, special metals such as titanium, nickel, zirconium, chromium, inconel, hastelloy, general metals such as aluminum, copper, stainless steel, zinc, magnesium, iron, and alloys containing these general metals or oxidation of these general metals Can be used. Further, the above-described metal, alloy, or oxide film may be formed on another inorganic material by various plating and vacuum deposition, a CVD method, a sputtering method, or the like.

  It should be noted that a natural oxide thin film is usually formed on the metal surface and the alloy surface thereof, and when the film-like support is formed from a silane compound, the substrate and the film-like support are made using this natural oxide thin film. The body can be firmly fixed. In this case, it is preferable to remove oil and dirt adhering to the surface of the oxide thin film in advance by an ordinary known method in order to fix stably and firmly. Also, instead of using a natural oxide film, an oxide thin film is chemically formed on a metal surface or alloy surface by a known method, or an oxide thin film is formed by a known electrochemical method such as anodic oxidation. Also good.

  Furthermore, examples of ceramics used for the base material 31 include ceramics such as earthenware, earthenware, plaster, magnetism, and ceramics such as glass, cement, gypsum, enamel, and fine ceramics. Examples of the composition of the ceramic to be configured include elemental, oxide, hydroxide, carbide, carbonate, nitride, halide, and phosphate ceramics. These composites may be used.

  Further, as the ceramic used for the substrate 31, further, barium titanate, lead zirconate titanate, ferrite, alumina, forsterite, zirconia, zircon, mullite, steatite, cordierite, aluminum nitride, silicon nitride, Examples thereof include silicon carbide, new carbon, and new glass, and ceramics such as high-strength ceramics, functional ceramics, superconducting ceramics, nonlinear optical ceramics, antibacterial ceramics, biodegradable ceramics, and bioceramics.

  Moreover, as glass used for the base material 31, 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 Glasses such as glass, glass fiber, dichroic, gold stone (brown stone / sand gold stone / purple gold stone), glass ceramics, low melting point glass, metallic glass, and saphiret can be used.

  In addition to the base material 31, normal Portland cement, early-strength Portland cement, ultra-early strong Portland cement, medium heat Portland cement, low heat Portland cement, sulfate-resistant Portland cement, and Portland cement blast furnace slag, fly ash, It is possible to use cement 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, titania, zirconia, alumina, ceria (cerium oxide), zeolite, apatite, silica, activated carbon, diatomaceous earth, or the like can be used for the base material 31. Furthermore, a metal oxide made of chromium, manganese, iron, cobalt, nickel, copper, tin, or the like can be used for the substrate.
Furthermore, the base material 31 is made of heat such as polyimide, polyether ether ketone, polyphenylene sulfide, polyaramide, polybenzothiazole, polybenzoxazole, polybenzimidazole, polyquinoline, polyquinoxaline, fluororesin, phenol resin or epoxy resin. It is also possible to use a heat-resistant organic polymer material known to those skilled in the art, such as a curable resin.

  Next, an example of a method for obtaining the oxidation catalyst layer 33 of the present embodiment will be described. The oxidation catalyst layer 33 is formed, for example, by forming a membranous support 34 having mesopores 37 on a base material 31 having air permeability, and supporting the oxidation catalyst particles in the mesopores 37 of the obtained membranous support 34. Can be obtained.

In the method, first, the film-like support 34 is formed.
The membranous support 34 having the mesopores 37 is formed, for example, by forming a membranous precursor on the substrate 31 in a state in which a substance acting as a mesopore template inside the support is contained, and then the template It can be obtained by decomposing and removing the substance acting as.

An example of the method will be described. First, a solution containing a surfactant as a template and a hydrolyzate of alkoxysilane or metal alkoxide (hereinafter referred to as a precursor solution) is prepared. Specifically, alkoxysilane or metal alkoxide is added to a solution in which a surfactant as a template is dissolved, and pH is adjusted to hydrolyze the alkoxysilane or metal alkoxide. This produces a silanol group or a metal hydroxide. The surfactant forms micelles in the solution and becomes a template for mesopores.
The precursor solution is applied to the base material 31 and heated to volatilize the solvent, and the silanol group or metal hydroxide is condensed and cured to form a precursor of the film-like support on the surface of the base material 31. . Thereafter, by further baking to a high temperature of 300 ° C. or higher, the surfactant as a template in the precursor is removed by decomposing and volatilizing, and the membranous support 34 having mesopores is obtained.

For example, the precursor solution can include three components: (1) a hydrolyzate of alkoxysilane or metal alkoxide, (2) a solvent (solvent), and (3) a surfactant. Since water is necessary when hydrolyzing the alkoxysilane or metal alkoxide in a solution, the solvent is preferably a water or a mixed solvent of water and a water-soluble organic solvent such as methanol or ethanol. . Further, a catalyst for hydrolysis treatment of alkoxysilane or metal alkoxide may be further included in the solution, and it is preferable to use an acid such as nitric acid or hydrochloric acid as the catalyst.
The ratio of the surfactant, alkoxysilane, or metal alkoxide is not particularly limited and can be set as appropriate. By changing the molar ratio of surfactant / alkoxysilane or metal alkoxide, the pore volume ratio and the porosity of the obtained membrane-like support 34 can be controlled.

  In order to obtain a film-like support 34 having a more uniform film thickness, it is preferable not to generate a precipitate in the precursor solution before application to the substrate 31, and the precursor is obtained by using an alcohol solution having an acidic pH. Precipitation can be avoided. Alternatively, the precipitation can be achieved by adjusting only the molar ratio of water to alkoxysilane or metal alkoxide, adjusting the molar ratio with pH adjustment, or adding alcohol, or both molar ratio adjustment and alcohol addition. It can also be avoided.

As the surfactant, polyoxyethylene ether, polyalkylene oxide block copolymer and the like can be used. As 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. Examples of the polyalkylene oxide block copolymer include block copolymers of ethylene oxide and propylene oxide.

  Since the differential length of the surfactant affects the mesopore diameter, the surfactant may be selected according to the target mesopore diameter. Moreover, you may make it add hydrophobic compounds, such as mesitylene, Since the said hydrophobic compound can increase the micelle diameter in a precursor solution, it can be used for preparation of a mesopore diameter.

  The alkoxysilane used is tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane. Hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, and the like. As the metal alkoxide, tetrapropoxyaluminum, tetrapropoxytin, tetrapropoxytitanium, tetrapropoxyzirconium and the like can be used.

  The method of applying the precursor solution to the base material 31 is not limited as long as the precursor solution can be uniformly and thinly applied to the base material 31, but the unnecessary solution is blown off after the spin coating method or the base material is immersed in the precursor solution. The Dip & Blow method can be applied, and it may be selected according to the shape of the substrate to be applied. Moreover, the heating conditions for removing the template molecules after forming the precursor are not particularly limited, and for example, the precursor may be heated at 300 to 600 ° C.

Next, the oxidation catalyst particles are supported on the mesopores 37 of the membrane support 34 to obtain the oxidation catalyst layer 33 of the present embodiment.
First, the mesopores of the membranous support are brought into contact with the membranous support 34 and a solution in which a platinum compound and / or a palladium compound corresponding to the oxidation catalyst particles to be supported are dissolved (hereinafter referred to as a metal compound solution). Introduce a metal compound solution. Then, the oxidation catalyst layer 33 of the present embodiment can be obtained by performing oxidation and / or reduction treatment to form oxidation catalyst particles in the mesopores.

Specifically, for example, after the film-like support 34 is immersed in a metal compound solution, firing and / or reduction treatment can be performed.
More specifically, while heating and stirring the metal compound solution at 20 to 90 ° C., preferably 50 to 70 ° C., the pH is adjusted to 3 to 10, preferably 5 to 8, using an alkaline solution. Thereafter, the base material 31 on which the film-like support 34 is formed is immersed in the metal compound solution, followed by vacuum degassing treatment to infiltrate the metal compound solution into the pores, and then 200 to 600 By carrying out a heat baking treatment at 0 ° C., particles containing platinum oxide and / or palladium oxide in the pores can be obtained.

  Moreover, after making a metal compound solution osmose | permeate as mentioned above, it immerses in the hydrogen reduction method which performs the baking process of 200-600 degreeC, and the process exposed to a 100-300 degreeC hydrogen stream, or a sodium borohydride solution. The oxidation catalyst particles can also be obtained in the pores by performing a known reduction operation such as a liquid phase reduction method. Depending on the type of platinum compound and / or palladium compound to be used, the oxidation catalyst particles can be obtained in the pores only by heating and baking at 200 to 600 ° C. without performing the above-described known reduction operation. Further, the reduction of platinum oxide and / or palladium oxide may be limited to a part, and platinum and / or palladium alone and platinum oxide and / or palladium oxide may coexist in the oxidation catalyst particles in the mesopores. .

Examples of the platinum compound used include chloroplatinic acid, dinitrodiammine platinum, and dichlorotetraammine platinum. Examples of the palladium compound include dinitrodiammine palladium and ammonium chloropalladate.
The concentration of the platinum compound and / or palladium compound in the platinum compound and / or palladium compound solution is not particularly limited, but it is the oxidation catalyst produced that the solution is prepared as 1 × 10 ⁻² to 1 × 10 ⁻⁵ mol / L. This is preferable because the particles are less likely to aggregate.

Next, the mechanism 10 that blows the gas to be processed to the oxidation catalyst layer 33 according to the present embodiment will be described. The mechanism corresponds to the gas supply unit of the present invention, and is hereinafter also referred to as a blower mechanism 10.
The blowing mechanism 10 according to the present embodiment forcibly brings the gas to be treated into contact with the oxidation catalyst layer 33 by blowing the gas to be treated to the oxidation catalyst layer 33 (FIG. 1). Thereby, the organic gas concentration contained in the gas can be reduced more efficiently. Therefore, the blowing mechanism 10 only needs to be able to deliver an amount of air that can be oxidized by the catalyst of the catalyst layer 33, and the necessary amount of air may be designed based on the capacity design of the device, but the space velocity of the air is 10,000 / h or more and 150,000. / h or less is desirable.
When the space velocity of the air blow is less than 10,000 / h, the amount of gas to be processed delivered to the oxidation catalyst layer 33 is small, and the amount of organic gas oxidized and removed is also small. The amount of reduction in organic gas concentration in the installed environment is small. Moreover, since the oxidation removal rate of the catalyst is reduced when the space velocity is higher than 150,000 / h, the reduction of the organic gas concentration in the gas to be treated is small, and the apparatus is installed as compared with the case of being within the range. Reduces the amount of organic gas concentration in the environment.
The above space velocity is defined as the volume of the gas to be processed that has passed through the catalyst layer divided by the volume of the catalyst layer.

  The gas to be treated flows in a direction (Y-axis direction in FIG. 2) perpendicular to the film thickness direction of the oxidation catalyst layer (film-like support), and the gas to be treated diffuses and penetrates into the oxidation catalyst layer 33. The form to do is desirable. As shown in FIG. 3, if the gas to be treated is caused to flow parallel to the film thickness direction of the oxidation catalyst layer, all the gas to be treated must pass through the mesopores 37 of the oxidation catalyst layer 33. It becomes difficult to obtain the above-mentioned preferable space velocity.

  In addition, when the oxidation catalyst layer 33 is formed on the surface of the fiber assembly such as a mesh or a non-woven fabric, if the oxidation catalyst layer 33 is formed so as not to block the opening of the fiber assembly, microscopically, the fiber assembly An oxidation catalyst layer 33 is formed on the surface of each fiber. That is, the base material 31 in FIG. 2 corresponds to one of the fibers forming the fiber assembly. At this time, the gas to be treated can flow along the surface of each fiber. Therefore, even if the gas to be processed is transmitted in the same direction as the gas is normally transmitted to the filter, that is, the direction perpendicular to the plane of the fiber assembly, the above-mentioned gas to be processed is in the film thickness direction of the oxidation catalyst layer. It is possible to satisfy an orthogonal flow state and obtain a suitable space velocity.

The blower mechanism 10 may be a known blower such as the electric fan 11 and is not particularly limited. In addition, although the ventilation mechanism 10 comprised by a ventilation apparatus etc. was mentioned as an example and demonstrated as a gas supply part, it is not limited to this, It is comprised so that to-be-processed gas may be supplied to the oxidation catalyst layer 33 in the apparatus 100. It only has to be.
Moreover, you may arrange | position the ventilation mechanism 10 so that the airflow produced by the ventilation mechanism 10 etc. may contact functional layers other than the member provided with the catalyst layer 33 and the antibacterial agent mentioned later. For example, a dustproof filter that removes suspended matters such as dust in the air may be installed as a functional layer upstream of the oxidation catalyst layer 33 in the air flow direction. By installing a dustproof filter, it contributes to preventing the suspended matter in the air from adhering to the oxidation catalyst layer 33 and inhibiting the contact between the gas to be treated and the oxidation catalyst layer 33 and preventing the decomposition of the organic gas from proceeding. Can do.

  The power source of the blower mechanism 10 such as the electric fan 11 may be alternating current or direct current. In the case of direct current, power may be supplied to the device 100 through a built-in primary or secondary battery or via an AC adapter. When the battery is built-in, the device 100 can be easily placed in a storage without an outlet. The apparatus 100 can be installed. On the other hand, in the case of an AC power source or a DC power source converted by an AC adapter, there is no need for battery replacement required for a built-in battery power source, and continuous operation can be easily performed. The type of power source may be appropriately selected according to the installation conditions of the device 100.

  In the apparatus 100 of the present embodiment, the gas to be treated is disposed on the member 50 such as a filter carrying a compound having at least one of antibacterial property, antifungal property, and antiviral property (hereinafter also simply referred to as an antibacterial agent). You may install in the at least one before and behind in the air distribution direction of the member 30 which has the oxidation catalyst layer 33 so that it may permeate | transmit (FIG. 4). By killing bacteria, mold spores, and viruses floating in the gas to be treated, especially in the atmosphere, it also prevents the deterioration caused by bacteria, molds, and viruses in articles and building interiors such as fruits and vegetables stored in the environment. Can be granted.

An antibacterial agent means a substance capable of killing bacteria and / or molds and / or viruses. Examples of the antifungal compound include silver, copper, zinc, tin, magnesium, calcium, strontium, aluminum, manganese, nickel, titanium and other inorganic compounds such as phosphates and halogen salts, or these metals. As inorganic compounds or organic compounds supported on zeolite or the like, organic acid salts such as 8-oxyquinoline copper and sodium diacetate, halogenated organic compounds such as triclosan, chlorohexidine and 3-iodo-2-propylbutylcarbamate, bronopol Pyridines such as chlorothalonil and methylsulfonyltetrachloropyridine, imidazoles such as enylconazole, triazines such as N, N ', N "-trishydroxyethylhexahydro-s-triangine, biphenyl and orthophenylphenol Aromatic compounds such as enol, zinc pyrithione, benzalkonium chloride, benzethonium chloride, cetylpyridium chloride, alkyltrimethylammonium salts and other organic salts and complexes, chitin, chitosan, catechin, hinokitiol, mustard, wasabi essential oil, polylysine Compounds known to those skilled in the art such as natural organic compounds such as can be used.
Compounds having at least one of antibacterial and antiviral properties (hereinafter referred to as antibacterial and antiviral agents) include atoms such as polyphenol compounds, quaternary ammonium salts, inorganic copper compounds, inorganic silver compounds, zinc, iron and the like. Inorganic compounds containing copper, organic compounds containing atoms such as copper, silver, zinc, iron, platinum, iodine compounds, pyridine compounds, ester compounds, sulfamide compounds, and the like.
These antibacterial agents and the like may be contained in combination of two or more.

  The antibacterial antiviral agent contained in the member 50 carrying the antibacterial agent is preferably a substance that is relatively safe and exhibits high bactericidal and / or antiviral properties in a small amount. Specifically, the antibacterial antiviral agent is a compound selected from the group consisting of a polyphenol compound, a quaternary ammonium salt, an inorganic copper compound and an inorganic silver compound, or an organic compound and copper, silver, It is preferable to contain a salt with zinc or iron. A compound selected from at least one selected from the group consisting of silver iodide (I), copper iodide (I), and copper thiocyanate (I) is more effective and preferable.

  The form of the antibacterial agent in the member 50 carrying the antibacterial agent is not particularly limited as long as the air permeability of the gas to be treated is not hindered, but a particulate form that does not easily affect the air permeability is preferable. The size of the antibacterial agent particles is not particularly limited and can be appropriately set by those skilled in the art, but is preferably fine particles having an average particle diameter of 1 nm or more and less than 500 nm. If it is less than 1 nm, the material becomes unstable, so that the antibacterial agent particles aggregate and are difficult to form on the substrate. Moreover, when it is 500 nm or more, it will fall rather than the case where adhesiveness with a base material exists in the range. The average particle size of the antibacterial agent particles is a volume average particle size (D50), and can be measured using a particle size distribution meter.

  Examples of polyphenol compounds include catechin, anthocyanin, flavone, isoflavone, flavan, flavanone, rutin, theaflavin, tannin, chlorogenic acid, ellagic acid, gallic acid, propyl gallate, lignans, curcumins, and coumarins. .

  The quaternary ammonium salts include benzalkonium chloride, benzethonium chloride, methylbenzethonium chloride, cetylpyridinium chloride, cetrimonium bromide, didecyldimethylammonium chloride, domifene, octyldecyldimethylammonium chloride, dioctyldimethylammonium chloride, Stearyldimethylbenzylammonium chloride, stearyltrimethylammonium chloride, stearylpentaethoxyammonium chloride, alkylisoquinolinium bromide, domifene bromide, dimethyliminopolyethylene chloride, dimethyldimethylammonium chloride, 3-chloro-2-hydroxypropyltrimethylammonium chloride 2,3-epoxypropyltrimethylammonium chloride, lauryl chloride trimethyla Monium, cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, N-decyl-N-isononyldimethylammonium chloride, dicetyldimethylammonium chloride, dimethyldistearylammonium chloride, myristyldimethylbenzylammonium chloride, laurylpyridinium chloride, cetylpyridinium chloride, Tri (polyoxyethylene) stearylmethylammonium chloride, tri (polyoxyethylene) oleylmethylammonium chloride, distearyldimethylammonium chloride, dodecyltrimethylammonium chloride, ditallowdimethylammonium bromide, dioleyldimethylammonium bromide, stearoyl N, N- Dimethylethylenediamide dimethyl sulfate quaternized product, distearoyl diethyl Triamine dimethyl sulfate quaternized, myristyl dimethyl ethyl ammonium chloride, dioctyl dimethyl ammonium chloride, didecyl dimethyl ammonium chloride, dicetyl dimethyl ammonium chloride, dilauryl dimethyl ammonium chloride, lauryl dimethyl benzyl ammonium chloride, myristyl dimethyl dichloro benzyl ammonium chloride, coco Examples thereof include alkyldimethylbenzylammonium chloride.

  The inorganic copper compound may be a monovalent copper compound or a divalent copper compound. Inorganic copper compounds include copper oxide (I), copper sulfide (I), copper iodide (I), copper chloride (I), copper acetate (I), copper hydroxide (I), copper bromide (I) , Copper peroxide (I), copper thiocyanate (I), copper hydroxide (II), copper oxide (II), copper chloride (II), copper acetate (II), copper sulfate (II), copper nitrate (II ), Copper fluoride (II), copper iodide (II), copper bromide (II), copper iodate, copper perchlorate, copper cyanide, copper chloride ammonium, copper tetraborate, ammonium copper sulfate, amidosulfuric acid Examples include copper, ammonium chloride, copper pyrophosphate, and copper carbonate.

  Inorganic silver compounds include silver oxide (I), silver sulfide, silver iodide, silver chloride, silver bromide, copper peroxide (I), silver thiocyanate, silver sulfate, silver fluoride, silver iodate, perchlorine Examples thereof include silver oxide, silver cyanide, silver tetrafluoroborate, silver amidosulfate, silver copper hexafluorophosphate, and silver carbonate.

  Examples of the salt of an organic compound and copper include, for example, copper formate, copper acetate, copper propionate, copper butyrate, copper valerate, copper caproate, copper enanthate, copper caprylate, copper pelargonate, copper caprate, mistin Copper oxide, copper palmitate, copper margarate, copper stearate, copper oleate, copper lactate, copper malate, copper citrate, copper benzoate, copper phthalate, copper isophthalate, copper terephthalate, copper salicylate, melitto Copper oxide, copper oxalate, copper malonate, copper succinate, copper glutarate, copper adipate, copper fumarate, copper glycolate, copper glycerate, copper gluconate, copper tartrate, copper acetylacetone, copper ethylacetoacetate, iso Copper valerate, copper β-resorcylate, copper diacetoacetate, copper formyl succinate, copper salicylamine acid, copper bis (2-ethylhexanoate), copper sebacate, copper naphthenate Oxine copper, copper acetylacetonate, ethyl acetoacetate copper trifluoromethanesulfonate, copper phthalocyanine, copper ethoxide, copper isopropoxide, copper methoxide, dimethyl dithiocarbamates include pyrithione copper.

  Salts of organic compounds and silver include silver acetate, silver propionate, silver butyrate, copper valerate, silver caproate, silver caprylate, silver caprate, silver myristate, silver palmitate, silver margarate, stearic acid Silver, silver oleate, silver neodecanoate, silver lactate, malic acid, silver citrate, silver phthalate, silver isophthalate, silver terephthalate, silver salicylate, silver benzoate, silver melitrate, silver toluenesulfonate, oxalic acid Silver, silver malonate, silver succinate, silver glutarate, silver adipate, silver fumarate, silver glycolate, silver glycerate, silver gluconate, silver tartrate, acetylacetone silver, ethyl ethylacetoacetate, silver isovalerate, β -Silver resorcylate, silver diacetoacetate, silver formylsuccinate, silver 2-ethylhexanoate, silver sebacate, silver naphthenate, silver trifluoromethanesulfonate, Taroshianin silver, silver ethoxide, silver isopropoxide, silver methoxide, diethyldithiocarbamate, silver silver pyrithione and the like.

  Examples of the salt of an organic compound and iron include ferric citrate / n-hydrate, iron gluconate, iron citrate, iron fumarate, iron oxalate, and iron phthalocyanine.

  In addition, as a salt of an organic compound and zinc, zinc citrate, zinc gluconate, zinc malate, zinc formate, zinc lactate, zinc oxalate, pyrithione zinc, bis (dimethyldithiocarbamate) zinc, ethylenebis (dithiocarbamate) ) Zinc, zinc acetate, zinc acrylate, zinc benzoate, zinc butyrate, zinc glycerate, zinc glycolate, zinc picolinate, zinc propionate, zinc salicylate, zinc tartrate, zinc undecylenate, zinc malonate, zinc succinate , Zinc phthalocyanine, zinc glutarate, zinc phenolsulfonate, zinc cresolsulfonate, zinc toluenesulfonate, zinc benzenesulfonate, zinc methanesulfonate, zinc 2-propanolsulfonate, and the like.

  For example, as one embodiment, as shown in FIG. 4, the above-described antibacterial agent or the like may be carried on a base material and installed further upstream in the air flow direction of a member having an oxidation catalyst layer. The mode of carrying is not particularly limited, and a method known to those skilled in the art may be used. For example, an antibacterial agent such as particles may be adsorbed or adhered to the surface of the substrate. Adsorption or adhesion may be physical adhesion by physical interaction such as electrostatic attraction or van der Waals force, or may be based on The material and antibacterial agent particles may be chemically bonded by chemical bonding via a coupling molecule such as a silane monomer, but chemical bonding is desirable because the base material and the antibacterial agent are firmly bonded.

  For physical adhesion, the base material is immersed in a solvent in which an antibacterial agent or the like is dispersed, and then the dispersed solvent is volatilized. As the solvent for dispersing the antibacterial agent, general-purpose solvents such as water, methanol, ethanol, MEK, acetone, xylene, and toluene can be used.

  In order to adhere more firmly, the surface of the substrate may be previously hydrophilized by plasma treatment or a resin binder may be added. A known binder can be used as the resin binder. Specific examples include polyester resin, amino resin, epoxy resin, polyurethane resin, acrylic resin, water-soluble resin, vinyl resin, fluororesin, silicon resin, fiber resin, phenol resin, xylene resin, toluene resin, and natural resin. May be dry oils such as castor oil, linseed oil and tung oil.

  Chemical adhesion is fixing to a substrate through a chemical bond with a binder. The binder to be used is not particularly limited, but the silane monomer and the oligomer that is a polymer thereof have a low molecular weight, and therefore, the contact between the antibacterial agent particles and the bacteria is low and effective. It is preferable because it can be sterilized. Moreover, since the molecular weight is low, the adhesiveness with the base material is high, and the antimicrobial agent particles can be stably supported on the base material.

Specific examples of the silane monomer include silane monomers represented by a general formula of X—Si (OR) _n (n is an integer of 1 to 3). X is a functional group that reacts with an organic substance, such as a vinyl group, an epoxy group, a styryl group, a methacrylo group, an acryloxy group, an isocyanate group, a polysulfide group, an amino group, a mercapto group, or a chloro group. OR is an alkoxy group such as a hydrolyzable methoxy group or ethoxy group, and the three functional groups related to the silane monomer may be the same or different. These alkoxy groups composed of methoxy groups and ethoxy groups are hydrolyzed to form silanol groups. It is known that functional groups having silanol groups, vinyl groups, epoxy groups, styryl groups, methacrylo groups, acryloxy groups, isocyanate groups, and unsaturated bonds have high reactivity. Particles such as antibacterial agents are firmly held on the surface of the base material by chemical bonding through such a reactive silane monomer.

  Examples of the silane monomer represented by the above general formula include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-amino. Propyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxy Silane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- Methacryloki Cypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-aminopropyltrimethoxysilane 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-2- (aminoethyl)- 3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane 3-mercaptopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, special aminosilane, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, methyltrimethoxy Silane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, hexamethyldisilazane, hexyltrimethoxysilane, decyltrimethoxysilane, hydrolyzable group-containing siloxane, fluoroalkyl group-containing oligomer, methylhydrogensiloxane, Examples thereof include silicone quaternary ammonium salts.

  Examples of the silane oligomer include KC-89S, KR-500, X-40-9225, KR-217, KR-9218, KR-213, and KR-510 manufactured by Shin-Etsu Chemical Co., Ltd., which are commercially available. These silane oligomers may be used alone or in combination of two or more, and may be used in combination with one or more of the aforementioned silane monomers.

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples.

Example 1
10.4 g of tetraethoxysilane (TEOS) was put in a beaker, and 12.0 g of ethanol was further added. To this, 4.5 g of 0.01M hydrochloric acid was further added and stirred at room temperature for 20 minutes (solution A). In a separate beaker, 3.3 g of a nonionic surfactant (Brij56) and 8.0 g of ethanol were added and stirred at room temperature for 30 minutes (Liquid B). Then, B liquid was added to A liquid, mixed under room temperature conditions, and further stirred for 3 hours to obtain a precursor solution of mesoporous silica. A ceramic honeycomb (manufactured by Iwatani Corporation) serving as a base material was immersed in the mesoporous silica precursor solution, and the pressure was reduced for 15 minutes. Thereafter, the ceramic honeycomb was pulled up, and the excess solution was removed by air blowing. Then, the temperature was raised at 1 ° C./min and fired at 450 ° C. for 4 hours to obtain a ceramic honeycomb substrate on which the mesoporous silica film was fixed.
Thereafter, the ceramic honeycomb with the mesoporous silica film immobilized thereon is immersed in a solution containing diamine dinitroplatinum nitrate, and the excess solution is removed by air blow, and the mixture is reduced to 250 ° C. in a reducing gas containing 10% hydrogen gas and 90% nitrogen gas. After firing for 1 hour, a honeycomb substrate having a platinum oxidation catalyst layer was obtained.
The amount of Pt supported on the mesoporous silica film (including Pt particles, hereinafter the same) was 1 wt%. When the pore diameter was measured by the BET method, it was 3.2 nm. The mesoporous silica film had a thickness of 500 nm. Moreover, when the particle size of Pt was observed with TEM, it was 2.8 nm.
A blower mechanism (fans the gas to be treated in the direction perpendicular to the film thickness direction, the same as in Comparative Example 1) is attached so that the gas to be treated passes through the oxidation catalyst layer of the obtained honeycomb substrate, and the organic gas reduction device is installed. Produced.

(Comparative Example 1)
A titanium oxide coating agent (ST-K211 manufactured by Ishihara Sangyo Co., Ltd.) was placed in a beaker, and a ceramic honeycomb (manufactured by Iwatani Sangyo Co., Ltd.) was further immersed therein, and the pressure was reduced for 15 minutes. Thereafter, the ceramic honeycomb was pulled up, and the excess solution was removed by air blowing. Then, the temperature was raised at 1 ° C./min and fired at 450 ° C. for 4 hours to obtain a ceramic honeycomb coated with titanium oxide.
A blower mechanism was attached so that the gas to be treated permeated into the oxidation catalyst layer of the obtained honeycomb substrate, and an organic gas reduction device was produced.

[Test Example 1]
The inside of the sealed space with a volume of 120 L was adjusted so that the temperature was 5 ° C., the humidity was 90%, and the ethylene concentration was 0.5 ppm. Thereafter, the organic gas reduction device of Example 1 was installed in the sealed space, and the change in ethylene concentration in the sealed space over time was blown to the honeycomb substrate having the oxidation catalyst layer at a space velocity of 48,000 / h. Measured. The space velocity was calculated from the air volume of 14.4 m ³ / h with respect to the volume of the oxidation catalyst layer of 300 cm ³ (10 cm × 10 cm × 3 cm).

[Test Example 2]
The test was performed in the same manner as in Test Example 11 except that the honeycomb substrate having the oxidation catalyst layer was blown at a space velocity of 96,000 / h. The space velocity was calculated from the air volume of 28.8 m ³ / h with respect to the volume of the oxidation catalyst layer of 300 cm ³ (10 cm × 10 cm × 3 cm).

[Test Example 3]
The test was carried out in the same manner as in Test Example 1 except that no organic gas reduction device was installed, and the concentration change of ethylene in the sealed space was measured over time.

[Test Example 4]
The test was performed in the same manner as in Test Example 1 except that the honeycomb substrate having the oxidation catalyst layer was blown at a space velocity of 300,000 / h. The space velocity was calculated from the air volume of 90 m ³ / h with respect to the volume of the oxidation catalyst layer of 300 cm ³ (10 cm × 10 cm × 3 cm).

[Test Example 5]
Similar to Test Example 4 except that the organic gas reduction device of Comparative Example 1 was installed, irradiated with ultraviolet rays having an ultraviolet illuminance of 10 W / m ² using a unit equipped with an ultraviolet lamp, and blown at a space velocity of 48,000 / h. It was carried out by the method. The space velocity was calculated from the air volume of 14.4 m ³ / h with respect to a volume of 300 cm ³ (10 cm × 10 cm × 3 cm) of the ceramic honeycomb coated with titanium oxide.

  From the results of Table 1, the ethylene concentration in the box after 6 hours of Test Examples 3 and 5 was 0.44 ppm to 0.46 ppm. On the other hand, in Test Examples 1, 2, and 4 using the apparatus of Example 1, the ethylene concentration in the box after 6 hours was 0.23 ppm or less, particularly in Test Examples 1 and 2, which was not detected, and 0 0.1 ppm or less. From the above, it has been shown that the apparatus of Example 1 can efficiently reduce ethylene at a low concentration of 0.5 ppm even in a low temperature and high humidity environment of 5 ° C. and a humidity of 90%.

DESCRIPTION OF SYMBOLS 10 Air blow mechanism 11 Electric fan 30 Member which has oxidation catalyst layer 31 Base material 33 Oxidation catalyst layer 34 Film-like support 35 Ventilation part 37 Mesopore 50 Member which has antibacterial agent 100 Organic gas reduction device

Claims (9)

A member having air permeability and having a membranous support formed on the surface thereof, and a gas supply unit for supplying a gas to be processed to the membranous support;
In the mesopores of the membrane-like support, oxidation catalyst particles containing one or more substances selected from the group consisting of simple substances of platinum and palladium and oxides thereof are supported. An organic gas reducing device that oxidizes an organic gas in a supplied gas to be treated.   2. The organic gas reducing device according to claim 1, wherein the organic gas contained in the gas to be treated is ethylene.   The gas supply unit has a blower mechanism that blows non-processed gas to the film-like support, and a space velocity of blown air by the blower mechanism is 10,000 / h or more and 150,000 / h or less. The organic gas reduction device according to 1 or 2.   The member according to any one of claims 1 to 3, further comprising a member supporting a compound having at least one of antibacterial property, antifungal property, and antiviral property, which is disposed on the upstream side in the air flow direction of the member. The organic gas reduction device according to claim 1.   5. The organic gas reduction device according to claim 1, wherein the film-like support has a thickness of 50 nm to 1000 nm. The membrane support is an organic emission reduction apparatus according to any one of claims 1 to 5, characterized in that it formed of SiO _2.   The organic gas reduction device according to any one of claims 1 to 6, wherein an average pore diameter of the mesopores measured by a BET method is 2 nm or more and 10 nm or less.   The organic gas reduction device according to any one of claims 1 to 7, wherein an average particle diameter of the oxidation catalyst particles is 1 nm or more and 10 nm or less.   A membranous support having mesopores and carrying oxidation catalyst particles containing a substance selected from the group consisting of platinum, palladium alone and oxides thereof in the mesopores A method for reducing an organic gas, characterized in that a gas to be treated is supplied and diffused to reduce the concentration of the organic gas contained in the gas.