JP2001276194A - Deodorizing catalyst material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deodorizing catalyst material capable of efficiently removing various odor components over a long period. SOLUTION: The deodorizing catalyst material contains an adsorbent, a photocatalyst and an inorganic complex composition. The adsorbent is an inorganic porous substance containing at least one kind selected from the group consisting of activated charcoal, high silica zeolite, silica gel, sepiolite, bentonite, and magnesium sulfide. The photocatalyst is either titanium oxide, zinc oxide, tin oxide or tungsten oxide. The inorganic complex composition contains a bivalent metal hydroxide and a tetravalent metal phosphate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a deodorizing catalyst material comprising an adsorbent, a photocatalyst and an inorganic composite composition.

[0002]

2. Description of the Related Art In recent years, there has been an increasing interest in various odors in living environments such as homes, offices, and hospitals. These odorous and harmful components include numerous compounds,
For example, ammonia, nitrogen-containing compounds such as amines (eg, trimethylamine, triethylamine, etc.),
Sulfur-containing compounds such as hydrogen sulfide and methyl mercaptan,
Aldehydes such as formaldehyde and acetaldehyde, and lower fatty acids such as formic acid, acetic acid, propionic acid and valeric acid are included. Thus, in the living environment, there are various odor components such as acidic odor components such as lower fatty acids, basic odor components such as nitrogen-containing compounds, neutral odor components such as sulfur-containing compounds and aldehydes. The actual malodorous components are complicated, and it is difficult to effectively remove a plurality of different types of components.

[0003] In recent years, studies on techniques for treating such malodors have become active, and various countermeasures such as a masking method, a chemical method, a biological deodorizing method, and an adsorption method have been proposed.

[0004] In order to remove malodorous substances, various deodorizing catalysts, for example, deodorizing catalysts in which an adsorbent is supported on fibers are used.

[0005] Photocatalysts such as titanium oxide have been used as deodorizing materials by utilizing their strong oxidizing power for maintenance-free purposes.

In addition, a deodorizing catalyst in which an adsorbent and titanium oxide are supported on fibers has been proposed.

However, as an adsorbent for removing odor components in gas, it is effective for either acidic components such as hydrogen sulfide or basic components such as ammonia, but not so effective for the other. Things are common.

[0008]

The deodorizing catalyst material which has been conventionally used is composed of only an adsorbent.
Since the adsorption capacity is limited, it has been impossible to deodorize when the adsorption amount of the odor component reaches the saturated adsorption capacity.

[0009] When a photocatalyst is used, the reaction takes place on a solid surface.
Once the components in the air are adsorbed on the catalyst surface
However, oxidation and titanium have a specific surface area of 30%.
0m ^Two/ G and not so large, so the adsorption speed
The photocatalyst alone was too slow and the performance was insufficient.

Further, in a deodorizing catalyst in which an adsorbent and titanium oxide are supported on fibers, even if the adsorbent has a sufficient adsorbing ability, the titanium oxide is a solid acid.
Adsorption to acid gas is performed only by the adsorbent,
Diffusion into titanium oxide is difficult. The acidic gas fills the adsorption site of the adsorbent without being diffused and decomposed, and the deodorizing effect is lost when the acid gas reaches the saturated adsorption capacity. For this reason, a separate catalyst for adsorbing the acid gas had to be prepared.

Accordingly, an object of the present invention is to provide a deodorizing catalyst material capable of efficiently removing various odor components for a long period of time. Another object of the present invention is to provide a deodorizing catalyst material having a high ability to remove acidic odor components and basic odor components. Still another object of the present invention is to provide a deodorizing catalyst material that can efficiently remove odor components regardless of the presence or absence of light irradiation. Still another object of the present invention is to provide a deodorizing catalyst material having the above excellent properties.

[0012]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that an adsorbent, a photocatalyst, and an inorganic composite composition, particularly an adsorbent for an inorganic porous substance, titanium oxide, By using a deodorizing catalyst material in which a photocatalyst having a photocatalytic function such as zinc oxide and a composite composition comprising a specific phosphate and hydroxide are used, it is possible to remove various odor components and remove odor components. Noh has been found to last for a long time, and the present invention has been completed.

[0013] The first invention provides a deodorizing catalyst material comprising an adsorbent, a photocatalyst, and an inorganic composite composition.

In the present invention, the adsorbent, which has adsorbed only a specific gas, exhibits high catalytic activity and can adsorb various odor components, because of the presence of the composite composition on the surface of each material. become. Even if the photocatalyst is a solid acid, the acidic gas is diffused into the photocatalyst, and a series of adsorption, diffusion, and decomposition reactions of the odor component occur, and the deodorizing effect is maintained for a long time.

According to a second aspect of the present invention, there is provided the deodorizing catalyst material according to the first aspect, wherein the adsorbent is an inorganic porous substance.

In the present invention, the inorganic porous material used has a large specific surface area, so that it has a high adsorption speed and is an excellent adsorbent. In the case of an alkaline odor, the odorous substance can be adsorbed on the porous portion or the odorous component can be combined (dissolved) with the moisture adsorbed on the porous portion to enable adsorption and deodorization. Adsorption of acidic odors such as hydrogen sulfide is also possible due to the presence of the composite composition. In addition, since it is an inorganic porous substance, it is not decomposed by its own photocatalyst, so that an intermediate product causing an unpleasant odor is not generated.

In the third invention, the deodorizing method according to the second invention, wherein the inorganic porous substance contains at least one selected from the group consisting of activated carbon, high silica zeolite, silica gel, sepiolite, bentonite, and magnesium sulfate. Provide a catalyst material.

In the present invention, the inorganic porous substance used adsorbs odorous components, and further supports a photocatalyst.
Although it is for fixing, it is desirable to use at least one member selected from the above group since general inorganic porous substances have a great difference in their ability to adsorb and fix a photocatalyst. When such a specific substance is used, the content of the photocatalyst in the deodorizing catalyst can be greatly improved.

In a fourth aspect of the present invention, the photocatalyst is any one of titanium oxide, zinc oxide, tin oxide and tungsten oxide. A catalyst material for deodorization.

In the present invention, when a malodorous component is decomposed by using a photocatalyst having a high activity and a high oxidizing power, the adsorbent or the photocatalyst itself recovers the adsorbing ability and adsorbs and fixes a further malodorous substance. By repeating the above operations, deodorization can be repeatedly performed over a long period of time. In particular, TiO2 is an anatase type, a brookite type,
Any of rutile type, amorphous type and the like may be used. Preferred TiO2 includes anatase type titanium oxide.

[0021] In a fifth aspect, the inorganic composite composition according to any one of the first to fourth aspects, wherein the inorganic composite composition contains a metal hydroxide and a metal phosphate. Provide a catalyst material for deodorization.

In the present invention, by using the inorganic composite composition, a mixed gel compound of a hydroxide and a water-insoluble phosphate is formed, and mixed with an adsorbent and a photocatalyst to obtain a specific odor component. However, the catalyst activity and adsorption capacity are improved, but various odor components can be efficiently removed over a long period of time.

According to a sixth aspect, there is provided the deodorizing catalyst material according to the fifth aspect, wherein the metal of the metal hydroxide is divalent.

In the present invention, a mixed gel compound of a hydroxide and a water-insoluble phosphate is produced by using a hydroxide of a divalent metal, and mixed with an adsorbent and a photocatalyst to form an acidic component, especially Sulfide deodorization is enhanced.

The divalent metal forming the hydroxide may be a divalent metal irrespective of the group of the periodic table. The divalent metal includes, for example, a periodic table group 1B element such as copper, a periodic table group 2A element such as magnesium, calcium, strontium and barium, a periodic table group 2B element such as zinc and cadmium, and a periodic table such as chromium and molybdenum. Examples include Group 7A elements, Group 7A elements such as manganese, and Group 8 elements such as iron, ruthenium, cobalt, rhodium, nickel, and palladium. These divalent metal hydroxides may be used alone or in combination of two or more.

Preferred divalent metals are transition metals, for example,
Periodic table group 1B element such as copper, periodic table group 2B element such as zinc, periodic table group 7A element such as manganese, iron, cobalt,
Includes Group 8 elements of the periodic table, such as nickel. Particularly preferred divalent metals include copper, zinc, and the like, and iron, cobalt, and nickel are also preferred.

These divalent metal hydroxides are generally insoluble or poorly soluble in a weakly acidic or weakly alkaline region (pH 4 to 10). The hydroxide may be crystalline, but is often amorphous. The hydroxide may be one kind or two or more kinds of metal hydroxides.

In the seventh invention, the metal hydroxide (M-
The catalyst for deodorization according to the fifth or sixth invention, wherein the metal of OH) has a low electronegativity.

In the present invention, when the electronegativity of the metal (symbol M) of the metal hydroxide is low, the metal tends to repel the electron pair of the oxygen ion, and the bond is weakened. Conversely, the O—H bond is strengthened, and the dissociation of MOH⇔M ⁺ + OH ⁻ is advantageous, and the surface metal ion acts as a base point, so that deodorization of acidic components, particularly sulfides, is enhanced.

The metals having a low electronegativity include, for example, lithium, sodium, potassium, rubidium, cesium, beryllium magnesium, calcium, strontium, barium, scandium, yttrium, titanium, zirconium, hafnium, vanadium, niobium,
Examples include tantalum, chromium, manganese, tungsten, zinc, cadmium, aluminum, gallium, and indium. Among these metals, zinc is particularly preferable, and magnesium, calcium, beryllium, and aluminum are also preferable.

According to an eighth aspect, there is provided the deodorizing catalyst material according to any one of the fifth to seventh aspects, wherein the metal of the metal phosphate is tetravalent.

In the present invention, when a tetravalent metal is used,
A mixed gel compound of the hydroxide and the water-insoluble phosphate is generated and mixed with the adsorbent and the photocatalyst, whereby the adsorbing ability of the adsorbent and the photocatalyst is improved.

The group in the periodic table is not particularly limited as long as the tetravalent metal forming the phosphate is a tetravalent metal.
The tetravalent metal includes a Group 4 element of the periodic table, for example, a Group 4A element (such as titanium, zirconium, hafnium, and thorium) and a Group 4B element (such as germanium, tin, and lead). Among these metals, metals belonging to Group 4A elements of the periodic table, for example, titanium, zirconium, hafnium, and Group 4B elements, for example, tin are preferable. Particularly, titanium and zirconium are preferable, and tin is also preferable.

The phosphoric acid constituting the phosphate includes various phosphoric acids, for example, orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid and the like. Phosphoric acid is often orthophosphoric acid, metaphosphoric acid or pyrophosphoric acid. Phosphates also include hydrogen phosphates such as ortho hydrogen phosphate. In addition, in this specification, unless specifically mentioned, "phosphoric acid" means orthophosphoric acid.

These tetravalent metal phosphates are usually insoluble or poorly soluble in water. Further, the phosphate is
It may be a crystalline salt, but is preferably an amorphous salt. These tetravalent metal phosphates can be used alone or in combination of two or more.

According to a ninth aspect, there is provided a deodorizing catalyst member having a substrate whose surface is coated with the deodorizing catalyst material according to any one of the first to eighth aspects.

In the present invention, by coating the substrate surface with a deodorizing catalyst material, various odor components can be removed, and a catalyst having a long-lasting ability to remove odor components can be obtained.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples, but the present invention is not limited to these examples.

[0039]

EXAMPLE 1 Here, an example in which the inorganic porous material is activated carbon and the photocatalyst is titanium oxide will be described. Activated carbon and a phosphate mixture of titanium as a tetravalent metal and a titanium oxide mixture containing a hydroxide of zinc as a metal having a low valency and a low electronegativity of 5% by weight
The mixture was mixed at 0:50, a binder and water were added, and the mixture was dispersed to prepare a slurry. The slurry was applied to an inorganic base material and dried to obtain a base material holding the powder of the catalyst composition.

Comparative Example 1 Activated carbon and titanium oxide were added in an amount of 5% without adding the inorganic composite composition.
The mixture was mixed at 0:50, a binder and water were added, and the mixture was dispersed to prepare a slurry. The slurry was applied to an inorganic base material and dried to obtain a base material holding the powder of the catalyst composition.

Comparative Example 2 A binder and water were added to a titanium oxide mixture containing titanium phosphate and zinc hydroxide without adding an adsorbent, and the mixture was dispersed to prepare a slurry. The slurry was applied to an inorganic base material and dried to obtain a base material holding the powder of the catalyst composition.

The ability of the substrates obtained in Example 1 and Comparative Example to remove odor components was measured for hydrogen sulfide gas and ammonia gas as follows.

The obtained substrates were laminated at regular intervals, and set in an evaluation device as shown in FIG. Odor components (hydrogen sulfide, ammonia) were injected, and the air flow rate of the fan was set so that the inlet concentrations of the catalyst were 4 ppm of hydrogen sulfide and 20 ppm of ammonia, respectively.

Odor components were injected into the case where ultraviolet light was not irradiated, and the odor component was injected. The outlet concentration of the catalyst was measured using a detector tube to determine the initial deodorizing performance (removal rate).

[0045]

[Table 1]

As is clear from Table 1, when the catalyst obtained in Example 1 was used, the basic odor component and the acidic odor component could be removed without light irradiation, and the light irradiance was further increased by the light irradiation. It can be removed even more efficiently.

In this embodiment, as the inorganic porous material,
Activated carbon was used as a representative example. However, activated carbon and high silica zeolite tend to have a hydrophobic material surface, and exhibit excellent adsorption characteristics even in a system containing moisture in the atmosphere. In addition, adsorption to these is mainly physical adsorption by van der Waals force, reversible and desorbs by changing conditions such as high temperature and reduced pressure,
Concentration and recovery become possible. As a result, the photocatalyst is excellent in ability to adhere and has good adsorption power, so that it is suitably used, and good deodorizing performance can be obtained. Considering the characteristics mainly of physical adsorption, it is estimated that similar results can be obtained by using silica gel, sepiolite, bentonite, magnesium sulfate, or the like.

[0048]

[Brief description of the drawings]

Fig. 1 Photocatalyst deodorizer evaluation device

[Explanation of symbols]

 1 deodorizing catalyst 2 ultraviolet lamp 3 blower fan

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Claims (9)

[Claims] 1. A deodorizing catalyst material comprising an adsorbent, a photocatalyst and an inorganic composite composition. 2. The deodorizing catalyst material according to claim 1, wherein the adsorbent is an inorganic porous substance. 3. The deodorizing catalyst material according to claim 2, wherein the inorganic porous substance contains at least one selected from the group consisting of activated carbon, high silica zeolite, silica gel, sepiolite, bentonite, and magnesium sulfate. 4. The photocatalyst is titanium oxide, zinc oxide,
The deodorizing catalyst material according to any one of claims 1 to 3, wherein the material is any one of tin oxide and tungsten oxide. 5. The deodorizing catalyst material according to claim 1, wherein the inorganic composite composition contains a metal hydroxide and a metal phosphate. 6. The deodorizing catalyst material according to claim 5, wherein the metal of the metal hydroxide is divalent. 7. The deodorizing catalyst material according to claim 5, wherein the metal hydroxide has a low electronegativity of the metal. 8. The deodorizing catalyst material according to claim 5, wherein the metal of the metal phosphate is tetravalent. 9. A deodorizing catalyst member having a substrate whose surface is coated with the deodorizing catalyst material according to any one of claims 1 to 8.