JPH057776A - Catalyst and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a catalyst which can be used efficiently as an ozone decomposition catalyst or an ozone deodorizing catalyst, and provide an efficient manufacture for enhancing the performance of the catalyst. CONSTITUTION:A composition consisting of an Mn oxide and a metal Pd and/or a Pd oxide as essential ingredients is formed on a carrier in the form of a thin film. In addition, a catalyst consisting of the Mn oxide and Pd as essential ingredients is manufactured with alumina sol as a binder.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an ozone decomposition catalyst for catalytically decomposing and removing ozone contained in a gas, or catalytic oxidation of a malodorous component contained in a gas in the presence of ozone. The present invention relates to a catalyst body used as an ozone deodorizing catalyst for decomposition and removal, and a method for producing such a catalyst body.

[0002]

2. Description of the Related Art Ozone has a strong oxidizing ability, and when it decomposes it becomes harmless oxygen. Therefore, deodorizing, sterilizing, bleaching and C
It is widely used in various fields for the purpose of reducing OD. However, some of the ozone used for the above-mentioned purposes is released into the atmosphere in an unreacted state, which may cause secondary pollution such as photochemical smog. Further, when the aircraft flies in the stratosphere, air containing ozone is introduced into the aircraft, which may adversely affect passengers and tower crews. Further, in recent years, various high-voltage generators, such as dry-type copying machines, have become widespread, and even if the amount of ozone generated from these devices is very small, the interior of the room is contaminated, which is a situation that cannot be ignored for environmental hygiene. is there.

Ozone not only has an unpleasant odor, but also has a strong toxic effect on the human body. If the concentration exceeds a certain level, it damages the respiratory tract, and even if a minute amount, ozone is extremely harmful if inhaled for a long time. Therefore, it is desired to establish a technology for detoxifying waste ozone generated from various sources by decomposing and removing it.

The conventional waste ozone treatment methods are:
(I) Activated carbon treatment method, (II) Chemical cleaning treatment method, (III) Thermal decomposition treatment method, (IV) Ozone decomposition catalyst treatment method, etc. are known. The method is said to be the most advantageous method for ozone decomposition because it has no risk of ignition and explosion, does not require wastewater treatment, and can decompose and remove ozone at low cost.

As an ozone decomposition catalyst, various techniques have been developed up to now, but especially JP-A-62-976.
The catalyst disclosed in Japanese Patent Laid-Open No. 43-43 is an ozone decomposition catalyst having excellent characteristics, and it is necessary to heat the ozone decomposition catalyst in the related art at a high temperature, whereas the catalyst has a low temperature activity to increase the activity even at room temperature. It has been put to practical use as a usable ozone decomposition catalyst. However, in recent years, environmental problems have been particularly attracting attention, and there is a demand for a catalyst having even higher activity than conventional products even for ozone decomposition catalysts.

On the other hand, bad smell pollution has been widely taken up as a social problem, and deodorizing techniques for removing bad smell components causing bad smell have been studied from various angles. The deodorizing methods that have been used so far are (I) water washing method, (II) chemical washing method, (III) adsorption method, (IV) direct combustion method, (V) catalytic combustion method, (VI) ozone oxidation method Etc. are known, but each has advantages and disadvantages. Among them, the ozone oxidation method is a method of treating a malodorous component by utilizing the strong oxidizing action of ozone,
Since it can be carried out at a relatively low temperature such as room temperature, it is an advantageous method because the running cost is lower than that of the above various methods. However, there is a drawback that a long reaction zone is required because the reaction rate of ozone and malodorous components in the gas phase is small. Further, since unreacted ozone is released into the atmosphere, it has a drawback that it causes secondary pollution such as photochemical smog.

As a means for eliminating the above-mentioned drawbacks in the ozone oxidation method, a method using a catalyst has been proposed. In this method, a malodorous component is decomposed by a catalyst (hereinafter referred to as an ozone deodorizing catalyst) in the presence of ozone. According to this method, the malodorous components and ozone react rapidly without a large reaction space, and not only the deodorization efficiency is dramatically improved, but also ozone is completely decomposed and unreacted ozone is released into the atmosphere. Don't worry.

Various techniques have been developed as ozone deodorizing catalysts, but the effect may not be sufficiently exhibited depending on the use conditions. That is, when used continuously for a long period of time or when used under high humidity conditions, there is a drawback that the activity of the catalyst decreases early. Therefore, there is a demand for a catalyst having higher activity than conventional products.

[0009]

The present invention has been made in view of such circumstances, and its object is to provide a catalyst body which can be effectively utilized as an ozone decomposition catalyst or an ozone deodorization catalyst, and a catalyst body thereof. It is to provide a useful method for producing such a catalyst body.

[0010]

[Means for Solving the Problems] The catalyst body of the present invention which has achieved the above object is a composition containing Mn oxide and metal Pd and / or Pd oxide as essential components on a carrier. The point is that it is formed into a thin film. The catalyst body can be effectively used as an ozone decomposition catalyst for catalytically decomposing ozone contained in a gas or as an ozone deodorizing catalyst for catalytically oxidizing and decomposing a malodorous component in the presence of ozone.

The method for producing a catalyst body according to the present invention includes Mn oxide, metal Pd and / or Pd compound,
In addition, it has a gist in that a slurry containing an inorganic oxide sol as a binder is coated on a carrier. Further, the method for producing a catalyst body according to the present invention has a gist in that Mn oxide and metal Pd or Pd oxide are used as essential components and alumina sol is used as a binder. In carrying out the above-mentioned production method, it is optimum to form the catalyst body in the form of a thin film on the carrier, and such a form can maximize the performance of the catalyst body.

[0012]

The present inventors have investigated various aspects of the catalyst body that can be effectively used for the above-mentioned uses. First, the catalyst body containing Mn oxide and metal Pd and / or Pd oxide as essential components has a high ozone decomposing ability and a long life, and a high deodorizing ability in the presence of ozone. It was also found that it is excellent in the treatment effect of excess ozone.

According to the experiments conducted by the inventors of the present invention, by combining Mn oxide and Pd (metal Pd and / or Pd oxide), it is possible to obtain high performance which is not obtained by Mn oxide or Pd alone. It was found that, especially, Mn oxide alone or a composition containing Mn oxide impregnated and supported with Pd had extremely high ozone decomposing ability and ozone deodorizing ability. That is, Mn
The performance of the catalyst combining the oxide and Pd is more than the sum of the respective properties of the Pd-containing catalyst (however, not including Mn oxide) and the Mn oxide-containing catalyst (however, not including Pd). , Mn oxide and Pd coexist,
It was thought that they would mutually affect each other in the direction of improving the performance.

The present inventors have continued to earnestly research since then, from the viewpoint of further improving the performance of the above catalyst. As a result, it was found that the catalyst body of the present invention is most preferably used in the form of a thin film on a carrier, and in this form, the effect of the catalyst body of the present invention is fully exerted. .

That is, the catalyst body of the present invention comprises Mn oxide and
A composition containing metal Pd and / or Pd oxide as an essential component is formed in a thin film on a carrier.
Further, in the method for producing a catalyst body of the present invention, a carrier is coated with a slurry containing Mn oxide, metal Pd and / or Pd compound, and an inorganic oxide sol as a binder.

The catalyst body of the present invention contains Mn oxide and Pd (metal Pd and / or Pd oxide) as essential components, and the mixing ratio of both is 1: 1 in terms of atomic ratio of Mn and Pd.
About 0.001 to 1: 0.15 is suitable. The Mn oxide used in the present invention is not particularly limited, and various ones such as MnO, Mn ₃ O ₄ , Mn ₂ O ₃ , and MnO ₂ can be used, but electrolytic manganese dioxide (MnO ₂ MnO ₂ ). On the other hand, the starting material of Pd used in the present invention is not particularly limited, and examples thereof include palladium nitrate, palladium chloride, palladium sulfate,
Others (NH ₄ ) ₂ PdCl ₄ , [Pd (NH ₃ ) ₄ C
Various kinds of complex salts such as [1 ₂ ] can be used.

The carrier used in the present invention includes various carriers such as cordierite and other inorganic carriers, metal carriers and the like. Examples of the inorganic carrier include T
Although it can be composed of an oxide of one or more elements selected from the group consisting of i, Si, Al, Zr and Mg, these components exhibit excellent adsorptivity even at room temperature. Is a preferable coexisting component.

In the present invention, the overall shape of the catalyst body is not particularly limited, and may be honeycomb shape, pellet shape, cylindrical shape, cylindrical shape, plate shape, ribbon shape, corrugated plate shape, pipe shape, It can be formed into various shapes such as a donut shape and a lattice shape. Further, the thickness of the thin film is not particularly limited, but about 5 to 250 μm is suitable. Further, when the catalyst body of the present invention is used for ozone treatment, it can be applied over a wide range of the ozone content in the gas of about 0.01 to 50,000 ppm, but is not limited to this range.

As the inorganic oxide sol, alumina sol,
Examples thereof include silica sol, titania sol, zirconia sol, etc., and particularly when alumina sol is used as described later, a catalyst body having excellent performance can be obtained. As a method of coating the slurry on the carrier, for example, a method of immersing the carrier in the slurry for coating, a method of spraying the slurry on the carrier, or the like may be used.

More specific examples of the method for producing the catalyst body of the present invention include the methods (1) and (2) below. (1) Mn oxide, metal Pd and / or Pd compound,
Also, water is mixed, after appropriately heating and cooling, an inorganic oxide sol such as alumina sol or silica sol is added as a binder to form a slurry, and the carrier is immersed in the slurry and then taken out and blown with compressed air. A method of obtaining a catalyst body in which a catalyst component is coated in a thin film on a carrier by removing excess slurry attached and further drying and firing. (2) Mn oxide and water are mixed, heated appropriately, metal Pd and / or Pd compound is added and mixed, and after cooling, an inorganic oxide sol such as alumina sol or silica sol is added as a binder to form a slurry. Then, the carrier is dipped in the slurry, taken out, and compressed slurry is blown to remove the excessively attached slurry, and further dried and calcined to obtain a catalyst body in which the catalyst component is coated on the carrier in a thin film form. Method.

It has also been found that the performance of the catalyst body is further improved by using alumina sol as a binder during the production. That is, there are various binders used in the production of the catalyst body, such as inorganic ones and organic ones. Among them, the inorganic silica sol is most commonly used, but the alumina sol is used as the binder. According to the above, it was found that the above-mentioned expected catalyst performance-improving effect is remarkably obtained especially under high humidity conditions. Although the details of the reason why such an effect is obtained are not clear, there is no doubt that the catalyst in which Mn oxide and Pd are combined is favorably influenced by the coexistence of alumina. Is.

As described above, the catalyst body according to the present invention contains Mn oxide and Pd as essential components. Specifically, a composition comprising Mn oxide and Pd is prepared by using alumina sol and predetermined. In the form of a catalyst body and Mn
A catalyst body in which oxide and Pd are supported by alumina sol, a catalyst body in which a composition containing Mn oxide and Pd is formed into a thin film on a carrier by using an ordinary binder (silica sol, etc.), and further Mn oxide It is intended to include various forms such as a catalyst body in which a composition containing Pd and Pd is formed into a thin film on a carrier using alumina sol. In particular, the form is
The effect of the catalyst of the present invention can be maximized.

The procedure for producing the catalyst body using alumina sol is not particularly limited, but typical production methods include the following methods (1) and (2). (1) Mn oxide, metal Pd and / or Pd compound,
In addition, a method in which an alumina sol is kneaded, extrusion-molded, further dried and fired to obtain an integrally molded catalyst body. (2) Mn oxide, metal Pd and / or Pd compound,
Also, after immersing the carrier in a slurry containing alumina sol, removing it and removing compressed slurry by blowing compressed air, etc., and further drying and firing, a catalyst body coated with a catalyst component in a thin film is formed. How to get.

The present invention will be described in more detail with reference to the following examples. However, the following examples are not intended to limit the present invention, and any change in the design of the present invention can be made without departing from the spirit of the preceding and the following. It is included in the technical scope.

[0025]

EXAMPLES Example 1 A catalyst was prepared as follows. First, a composite oxide composed of Ti and Si was prepared by the following procedure. As a Ti source, a sulfuric acid aqueous solution of titanyl sulfate having the following composition was used. TiOSO ₄ 250 g / liter (as TiO ₂ ) Total H ₂ SO ₄ 1100 g / liter

Ammonia water (NH ₃ ,
(25%) 28 liters, and 2.4 kg of Snowtex-NCS-30 (Nissan Chemical's silica sol, containing about 30% by weight as SiO ₂ ) were separately prepared, and the sulfuric acid aqueous solution was added thereto. An aqueous solution of titanium-containing sulfuric acid diluted by adding 15.3 liters to 30 liters of water was gradually added dropwise with stirring to form a coprecipitated gel.
Let stand for 5 hours. TiO ₂ —Si thus obtained
The O ₂ gel was filtered, washed with water and dried at 200 ° C. for 10 hours.

Then, it was baked at 550 ° C. in an air atmosphere for 6 hours. The composition of the obtained powder is TiO ₂ : SiO ₂ =
It was 4: 1 (molar ratio) and the BET surface area was 185 m ² / g. Using the obtained powder (hereinafter referred to as TS-1 powder), an ozone decomposition catalyst was prepared by the procedure described below.

An appropriate amount of water was added to 10 kg of the above TS-1 powder, and well mixed by a kneader, and then sufficiently kneaded by a kneader, and a uniform kneaded product was extrusion-molded to have a vertical length of 50 mm,
Lattice honeycomb with width 50mm and length 50mm (wall thickness 0.15mm,
(Opening 0.89 mm) is manufactured and dried at 150 ° C for 5 hours,
Then, it was fired at 500 ° C. in an air atmosphere for 2 hours to obtain a honeycomb formed body.

Next, 450 g of manganese dioxide powder having a specific surface area of 45 m ² / g and an appropriate amount of water were added to a palladium nitrate aqueous solution containing 9 g of Pd, and the mixture was stirred and mixed at room temperature for 30 minutes.
Subsequently, the mixture was heated to 90 ° C. and kept stirring for 30 minutes, then cooled to room temperature, and an appropriate amount of silica sol was added to prepare a slurry.

The lattice honeycomb was immersed in the slurry for about 30 seconds. After that, it was taken out of the slurry, and the excess slurry in the cells was blown with compressed air to remove the clogging in all the cells, and then dried at 150 ° C. for 2 hours and calcined at 350 ° C. for 2 hours to obtain a finished catalyst. . The catalyst thus obtained was MnO 2 per liter of catalyst.
A thin film containing ₂ (75 g) and Pd (1.5 g) was formed on the carrier. The thickness of the thin film in the cell was 50 μm at the maximum corner portion and 5 μm at the minimum inner wall portion.

Example 2 Instead of TS-1 powder, γ-A having a specific surface area of 130 m ² / g
A lattice-shaped honeycomb was produced in the same manner as in Example 1 except that the l ₂ O ₃ powder was used, and a completed catalyst was obtained in the same manner as in Example 1 except that the lattice-shaped honeycomb was used. The catalyst thus obtained had MnO ₂ (75
A thin film containing g) and Pd (1.5 g) was formed on the carrier.

Example 3 A carrier made of alumina-silica inorganic fiber having a cross section of 500 gas inflow cells per square inch was used in place of the honeycomb formed body made of TS-1 powder. A completed catalyst was obtained in the same manner as in Example 1. The catalyst thus obtained had MnO 2 per liter of the catalyst.
A thin film containing ₂ (75 g) and Pd (1.5 g) was formed on the carrier.

Example 4 To 450 g of manganese dioxide powder having a specific surface area of 45 m ² / g, an appropriate amount of water was added, dispersed by stirring, heated to 90 ° C., and then P
A palladium nitrate aqueous solution containing d9 g was added dropwise. After completion of dropping, the mixture was stirred and maintained at 90 ° C. for 30 minutes, then cooled to room temperature, and an appropriate amount of silica sol was added to prepare a slurry.

Next, the lattice honeycomb obtained in Example 1 was immersed in the above slurry for about 30 seconds. After that, the slurry was taken out from the slurry, and the excess slurry in the cells was blown with compressed air to remove the clogging in all cells, followed by drying at 150 ° C for 2 hours and then firing at 350 ° C for 2 hours to obtain a finished catalyst. It was In the catalyst thus obtained, a thin film containing MnO ₂ (75 g) and Pd (1.5 g) was formed on the carrier per liter of the catalyst.

Example 5 Manganese dioxide having a specific surface area of 45 m ² / g was used.
A completed catalyst was obtained in the same manner as in Example 1 except that the amount was doubled to 00 g. In the catalyst thus obtained, a thin film containing MnO ₂ (150 g) and Pd (1.5 g) was formed on the carrier per liter of the catalyst.

Example 6 Instead of an aqueous palladium nitrate solution containing 9 g of Pd, 4.
A completed catalyst was obtained in the same manner as in Example 1 except that an aqueous palladium nitrate solution containing 5 g of Pd was used. The catalyst thus obtained had MnO ₂ (75
A thin film containing g) and Pd (0.75 g) was formed on the carrier.

Example 7 Dinitrodiaminopalladium [Pd (NH ₃ ) ₂ (NO ₃ ) ₂ ] was used in place of palladium nitrate, except that
A completed catalyst was obtained in the same manner as in Example 1. The catalyst thus obtained had MnO ₂ (75
A thin film containing g) and Pd (1.5 g) was formed on the carrier.

Example 8 A palladium nitrate aqueous solution containing 10.4 g of Pd was added to a manganese nitrate aqueous solution in which 1 kg of manganese nitrate [Mn (NO ₃ ) ₂ .6H ₂ O] was dissolved, and a 5% KMnO ₄ aqueous solution 1 was added with stirring.
0 liter was added dropwise. After completion of dropping, the mixture was further stirred for 1 hour, and then the precipitate was separated by filtration while sufficiently washing with distilled water. The solid obtained is dried at 120 ° C and then 400 ° C.
520 manganese dioxide containing 10.3 g of Pd after firing
g was prepared. Distilled water was added to the above manganese dioxide and wet-milled, and silica sol was subsequently added to prepare a slurry.

Next, the lattice honeycomb obtained in Example 1 was immersed in the above slurry for about 30 seconds. After that, it is taken out of the slurry, and the excess slurry in the cells is blown with compressed air to remove the clogging in all the cells, and then dried at 150 ° C for 2 hours and calcined at 350 ° C for 2 hours to obtain a finished catalyst. It was In the catalyst thus obtained, a thin film containing MnO ₂ (72 g) and Pd (1.4 g) was formed on the carrier per liter of the catalyst.

Example 9 A palladium nitrate aqueous solution containing 10 g of Pd was added to a manganese nitrate aqueous solution in which 1.65 kg of manganese nitrate [Mn (NO ₃ ) ₂ .6H ₂ O] was dissolved, and a 2N sodium hydroxide aqueous solution was added with stirring. 6.5 liters were dropped. After completion of dropping, the mixture was further stirred for 1 hour, and then the precipitate was separated by filtration while sufficiently washing with distilled water. The obtained solid was dried at 120 ° C. and further calcined at 400 ° C. to prepare 490 g of manganese dioxide containing 9.7 g of Pd. Thereafter, in the same manner as in Example 8, MnO ₂ (70 g) and Pd were added per liter of the catalyst.
A lattice-shaped honeycomb catalyst on which a thin film containing (1.4 g) was formed was obtained.

Comparative Example 1 The honeycomb formed body obtained in Example 1 was impregnated with an aqueous solution of manganese nitrate, dried at 120 ° C. for 3 hours, and fired at 450 ° C. for 3 hours. Subsequently, it was impregnated with an aqueous palladium nitrate solution, dried at 120 ° C. for 2 hours, and calcined at 450 ° C. for 2 hours to obtain a finished catalyst. The catalyst thus obtained contained TS-1 (408 g), MnO ₂ (1
02g) and Pd (2g).

Example 10 A durability test was conducted on each of the catalysts obtained in Examples 1 to 9 and Comparative Example 1. That is, each catalyst was filled in a stainless steel reaction tube, and air containing 150 ppm of ozone was supplied at a temperature of 25 ° C. and a relative humidity of 40% at a linear velocity of 0.5 m / sec (space velocity 72000 hr ⁻¹ ) for 80 hours. It was introduced into a catalyst layer and a durability test was conducted to investigate the ozone decomposition rate before and after the durability test. The ozone decomposition rate was measured before and after the durability test. The ozone concentration was 5 ppm, the temperature was 25 ° C, and the relative humidity was 40.
%, And the space velocity was 72,000 hr ^{−1, and} the ^value was calculated by the following equation (1). Ozone decomposition rate = (1−catalyst layer outlet side ozone concentration / catalyst inlet side ozone concentration) × 100 (1) The results are shown in Table 1, and a catalyst satisfying the requirements of the present invention has a high ozone decomposing ability. It is also clear that the excellent ozone decomposition rate is maintained even after the durability test for 80 hours.

[0043]

[Table 1]

Example 11 With respect to each of the catalysts obtained in Examples 1 and 4 and Comparative Example 1, the deodorization rate was determined as follows. That is, each catalyst was filled in a stainless steel reaction tube, and the temperature was 25 ° C and the relative humidity was 40
%, Air containing 20 ppm of methyl mercaptan and 20 ppm of ozone was introduced at a flow rate of 0.31 m / sec linear velocity (space velocity 45000 hr ⁻¹ ) to determine the deodorization rate after 22 hours. The deodorization rate was calculated by the following equation (2). Deodorization rate = (1-catalyst outlet side methylcaptan concentration / catalyst inlet side methylcaptan concentration) × 100 (2) The results are shown in Table 2, but the catalyst satisfying the requirements of the present invention is high even after 22 hours have passed. It can be seen that the deodorization rate is shown. After deodorization, there was almost no excess ozone, and ozone was almost completely decomposed.

[0045]

[Table 2]

Example 12 A catalyst composition slurry was prepared by the following means. After adding an appropriate amount of water to 450 g of manganese dioxide powder having a specific surface area of 45 m ² / g, stirring and dispersing the mixture, and heating to 90 ° C., Pd9
An aqueous palladium nitrate solution containing g was added dropwise. After completion of dropping, the mixture was stirred and protected at 90 ° C. for 30 minutes, then cooled to room temperature, and 761 g of alumina sol (milky white, containing about 10 wt% as Al ₂ O ₃ ) was added to prepare a slurry. The grid-shaped honeycomb obtained in Example 1 was added to the above slurry to about 3 times.
It was immersed for 0 seconds. After that, the slurry was taken out from the slurry, the excess slurry in the cells was removed by spraying compressed air to remove the clogging in all cells, followed by drying at 150 ° C. for 2 hours and then firing at 350 ° C. for 2 hours to obtain a finished catalyst. . The catalyst thus obtained is
A thin film containing MnO ₂ (75 g) and Pd (1.5 g) was formed on the carrier.

Example 13 Instead of using a milky white alumina sol, a yellow transparent alumina sol (containing about 10% by weight as Al ₂ O ₃ ) was used.
A completed catalyst was obtained in the same manner as in Example 12 except that 61 g was used.

Example 14 The amount of milky white alumina sol used was 761 g to 380 g.
A finished catalyst was obtained in the same manner as in Example 12 except that The catalyst thus obtained is
A thin film containing MnO ₂ (75 g) and Pd (1.5 g) was formed on the carrier.

Example 15 γ-A having a specific surface area of 130 m ² / g instead of TS-1 powder
A lattice-shaped honeycomb was produced in the same manner as in Example 1 except that 1 ₂ O ₃ powder was used, and a completed catalyst was obtained in the same manner as in Example 12 except that the lattice-shaped honeycomb was used. The catalyst thus obtained had MnO ₂ (75
A thin film containing g) and Pd (1.5 g) was formed on the carrier.

Example 16 A corrugated carrier made of alumina-silica inorganic fiber having a cross section of 500 gas inflow cells per square inch is used instead of the honeycomb formed body made of TS-1 powder. A completed catalyst was obtained in the same manner as in Example 12. In the catalyst thus obtained, a thin film containing MnO ₂ (75 g) and Pd (1.5 g) was formed on the carrier per liter of the catalyst.

Example 17 A completed catalyst was prepared in the same manner as in Example 12 except that a carrier having 600 gas inflow cells per square inch in cross section was used instead of the honeycomb formed body made of TS-1 powder. Obtained. In the catalyst thus obtained, a thin film containing MnO ₂ (75 g) and Pd (1.5 g) was formed on the carrier per liter of the catalyst.

Example 18 10 kg of manganese dioxide powder having a specific surface area of 45 m ² / g was added with P
A palladium nitrate aqueous solution containing 33.9 g of d was added dropwise, and after the addition was completed, the mixture was kneaded for 2 hours, and then alumina sol (milky white,
2030 g of Al ₂ O _{3 (} containing about 10% by weight) was added, mixed well with a kneader, and further thoroughly kneaded by a kneader. A uniform kneaded product is extruded and the external shape is 50 mm in length,
Lattice honeycomb with width 50mm and length 50mm (wall thickness 0.15
mm, opening 0.89 mm), dried at 150 ° C. for 5 hours, and then fired at 500 ° C. in an air atmosphere for 2 hours to obtain a honeycomb catalyst. The catalyst thus obtained had MnO ₂ (590 g) and Pd (2
g) was included.

Example 19 Alumina sol (milky white, about 10% by weight as Al ₂ O ₃
Instead of using 761 g of zirconia sol (Z)
A completed catalyst was obtained in the same manner as in Example 1 except that 304 g of rO _{2 (} containing about 25% by weight) was used. The catalyst thus obtained had MnO ₂ (7
A thin film containing 5 g) and Pd (1.5 g) was formed on the carrier.

Example 20 Alumina sol (milky white, about 10% by weight as Al ₂ O ₃
Instead of using 761 g of (containing), titania sol (Ti
A finished catalyst was obtained in the same manner as in Example 1 except that 761 g of O _{2 (} containing about 10% by weight) was used. The catalyst thus obtained had MnO ₂ (75
A thin film containing g) and Pd (1.5 g) was formed on the carrier.

Example 21 Alumina sol (milky white, about 10% by weight as Al ₂ O ₃
Instead of using 761 g of ceria) (CeO)
_A finished catalyst was obtained in the same manner as in Example 1 except that 572 g (containing about 13.3% by weight as ₂ ) was used. The catalyst thus obtained had MnO ₂ (7
A thin film containing 5 g) and Pb (1.5 g) was formed on the carrier.

Example 22 An ozone decomposition test was conducted on each of the catalysts obtained in Examples 1 and 12 to 21. That is, each catalyst was cut to a length of 25 mm, filled in a stainless steel reaction tube, and heated to a temperature of 2
0.5ppm ozone in an atmosphere of 5 ° C and 80% relative humidity
The contained air was introduced into the catalyst layer at a flow rate of 16.25 Nm ³ / hour (space velocity 260000 hr ⁻¹ ) and the ozone decomposition rate after 20 hours was investigated. The ozone decomposition rate was measured by the above formula (1). The results are shown in Table 3, and it can be clearly seen that the catalyst obtained by the present invention maintains an excellent ozone decomposition rate even with dilute ozone.

[0057]

[Table 3]

[0058]

The present invention is constituted as described above, and by adding the requirement of forming a thin film on a carrier and / or the requirement of using alumina sol as a binder during production, Mn oxide and Pd are added. It was possible to further improve the performance of the catalyst body containing as an essential component.

Claims (6)

[Claims] 1. A catalyst body comprising a Mn oxide and a composition containing metal Pd and / or Pd oxide as essential components formed in a thin film on a carrier. 2. A catalyst body according to claim 1, which is an ozone decomposition catalyst for catalytically decomposing ozone contained in a gas. 3. A catalyst body according to claim 1, which is an ozone deodorizing catalyst for catalytically oxidatively decomposing a malodorous component in the presence of ozone. 4. In producing the catalyst body according to claim 1, a carrier is coated with a slurry containing Mn oxide, metal Pd and / or Pd compound, and an inorganic oxide sol as a binder. Method for producing catalyst body. 5. The method for producing a catalyst body according to claim 4, wherein alumina sol is used as a binder as the inorganic oxide sol. 6. A method for producing a catalyst body, which comprises Mn oxide and metal Pd and / or Pd oxide as essential components and uses alumina sol as a binder.