JPS5820655B2 - Method for producing catalyst precursor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a precursor of a contact body, and more specifically, to a method for producing a precursor of a contact body, and more specifically, it is structured as a large molded body having microscopic gaps extending into the interior. This invention relates to a method for manufacturing the front and main body of a catalyst body, which allows a catalyst to be attached only to the surface of the carrier without penetrating the inside thereof.

In addition, the precursor of the catalyst body as used in the present invention refers to a state before becoming a catalyst body, and the precursor of the catalyst body of the present invention is heated at the decomposition temperature of an organic thermally decomposable substance. By doing so, the organic thermally decomposable substance can be decomposed and diffused, and the catalyst can be supported on the surface of the carrier to easily form a catalyst body.

In conventional catalyst precursors, the catalyst is supported not only on the surface of the carrier but also inside the carrier.

When a reaction is carried out on the surface of a catalyst, the catalyst inside cannot be utilized and expensive catalyst is wasted.

This problem is particularly noticeable when the catalyst body is used as a surface heating element to catalytically burn city gas, propane gas, etc., for example.

This is because when catalytically burning gas that contains almost no 02, such as city gas or propane gas, these gases mix with 02 when they pass through the catalyst and are catalytically combusted by the action of the catalyst. However, the only catalyst involved in this combustion is the catalyst that exists near the area where the gas mixes with 0□ - in other words, the catalyst that exists only near the surface of the catalyst body on the gas outlet side.

The reason why the catalyst is supported even inside the carrier is due to the manufacturing method of the precursor.

This is because the conventional manufacturing method is called the immersion method, in which the carrier is immersed in an aqueous solution of the metal salt, which causes the metal salt to penetrate into the interior of the carrier.

A method of brushing or spraying an aqueous solution of a metal salt onto the carrier has also been adopted; however, similar to the immersion method described above, the aqueous solution of the metal salt permeates into the inside of the carrier, and the metal salt coats the carrier. It gets inside.

There is also a method called precipitation method.

This is a process in which an alkali or the like is added to an aqueous solution of metal salts to form a precipitate, and then the precipitate is washed, filtered, and dried, and then molded with or without asbestos, diatoms, etc. This also has a catalyst inside the molded product.

The present inventors have conducted various studies to eliminate the above-mentioned drawbacks of conventional catalyst precursors, and have completed a method for producing a catalyst precursor as described below.

That is, there are the following two precursors of the catalyst body obtained by the present invention.

(1) A catalyst precursor characterized in that an organic thermally decomposable substance containing a catalyst is attached only to the surface of the carrier.

(2) An organic thermally decomposable substance is attached to the surface of the carrier,
A precursor of a catalyst body, further comprising an organic thermally decomposable substance containing a catalyst attached to its surface.

The precursor of the catalyst described above can be produced by the following three methods.

First, the precursor of the catalyst (1) above can be produced by the following two methods.

(b) A film made of an organic thermally decomposable substance containing a catalyst is placed on one surface of the carrier, and the pressure on the surface side of the carrier where the film is not placed is lower than that on which the film is placed. 1. A method for producing a precursor for a catalyst body, which comprises: closely adhering a film to the surface of a carrier; heating and melting the film; and depositing an organic thermally decomposable substance containing a catalyst only on one surface of the carrier.

Middle) Apply a solvent that dissolves an organic thermally decomposable substance to the surface of the carrier, and before the solvent dries, place a film made of an organic thermally decomposable substance containing a catalyst on the surface of the carrier, A method for producing a precursor for a catalyst body, which comprises dissolving the film in the solvent and depositing an organic thermally decomposable substance containing a catalyst on the surface of the carrier.

Further, the precursor of the catalyst in (2) above can be produced by the following method.

09 A solution made of an organic thermally decomposable substance is applied to the surface of the carrier, and before this solution dries, a film made of an organic thermally decomposable substance containing a catalyst is placed on the carrier surface, and the solution is bonded. A method for producing a precursor of a catalyst body, which comprises adhering an organic thermally decomposable substance containing a catalyst to the surface of a carrier by adhering the film as an agent.

Next, a detailed explanation of the present invention The organic thermally decomposable substance is, for example, an acrylic resin such as an acrylic ester resin or a methacrylic ester resin, or a solution of which is applied, such as starch, and then the solvent is removed. A substance that can form a film and decomposes when heated, leaving no residue.

The organic thermally decomposable substance containing a catalyst refers to the above organic thermally decomposable substance containing a catalyst.

When adding a catalyst to an organic thermally decomposable substance, it is necessary to add co-catalysts and fine catalyst carrier particles that improve the activity of the catalyst, and to check the affinity and dispersibility between the catalyst and the organic thermally decomposable substance. Solvents, surfactants, etc. may be added to improve the properties.

As the catalyst, platinum, palladium, rhodium, vanadium, cobalt, nickel, iron, copper, manganese, a metal effective for the desired reaction, or a metal salt is used.

The carrier material may be asbestos, glass fiber, diatomaceous earth, ceramic, etc., and is selected depending on the intended use of the catalyst.

Further, the shape of the carrier can be any shape depending on the purpose of application, such as flat plate, corrugated plate, cylindrical, spherical, etc.

A film made of an organic thermally decomposable substance containing a catalyst is a film formed by adding a catalyst to an organic thermally decomposable substance, or a film formed from an organic thermally decomposable substance. It refers to a product with a catalyst attached to it.

A solvent that dissolves an organic thermally decomposable substance is a solvent that has an affinity for the organic thermally decomposable substance.For example, when using acrylic resin as the organic thermally decomposable substance, the solvent should be acrylic. For example, alcohols, carboxylic acids, esters, ketones, benzene, toluene, xylene, and derivatives thereof, etc., which have an affinity with the system resin, can be used.

A method of placing a film made of an organic thermally decomposable substance containing a catalyst on one surface of a carrier and applying pressure to the surface side of the carrier where the film is not placed is lower than that on which the film is placed is to use a film. It depends on whether you apply reduced pressure on the side where the film is not placed or pressurize the side where the film is placed.

Examples of the present invention are shown below.

Example 1 A solution of 0.17 chloroplatinic acid dissolved in 301 rLl of n-butyl alcohol as a catalyst and LO-126-GH30P manufactured by Gooh Kagaku Kogyo Co., Ltd. as a 30% by weight acrylic acid ester copolymer were stirred. The obtained mixture was applied onto a glass plate (3Q Omm x 300mm) and air-dried to obtain a film made of an organic thermally decomposable substance containing a catalyst and having a thickness of Q, 1 mm.

Next, the ceramic fiber molded body (300mm x 300mm x
20 mm) was placed as a carrier in a rectangular funnel-shaped container with a depth of 15 mm, the film was placed on the top of the carrier, and a vacuum pump was applied from the tip of the funnel-shaped container to reduce the pressure on the lower surface of the carrier to transfer the film to the carrier. With the film in close contact with the top surface, heat the top surface of the film with a Bunsen burner. When the film begins to melt, stop suction, and then heat and melt the film with a burner to release organic heat containing catalyst onto the top surface of the carrier. A decomposable substance was attached to obtain a precursor of a catalyst body.

Example 2 Ceramic fiber molded body (300mmX 300mmX2
After applying isopropyl alcohol to one side of the carrier with a brush, a film made of an organic thermally decomposable material containing the same catalyst as that used in Example 1 was immediately placed on top of the isopropyl alcohol. The contact surface of the film was dissolved with alcohol, and an organic thermally decomposable substance containing a catalyst was adhered to the surface of the carrier to obtain a catalyst precursor.

Example 3 A ceramic fiber molded body (300 mm x 300 mm x 20 strips) was used as a carrier, and 35% by weight of an acrylic ester copolymer LO-12 manufactured by Gooh Kagaku Kogyo Co., Ltd. was coated on one surface of the carrier.
Immediately after brushing the 6GH solution, a film made of an organic thermally decomposable material containing the same catalyst as that used in Example 1 was placed on top of this, and the film was coated on a carrier using the solution as an adhesive. A catalyst precursor having an organic thermally decomposable substance containing a catalyst adhered to one surface of the catalyst was obtained.

When the catalyst precursor obtained in the example described above is heated at the decomposition temperature of the organic thermally decomposable substance, the organic thermally decomposable substance is decomposed and diffused, and the catalyst is supported on the surface of the carrier. It can be easily made into a catalyst.

As a heating method, a method using high-temperature gas is common, but a method using combustion exhaust gas, a method using infrared rays, a method using high frequency, a method using an electric heater,
A method using a gas burner, etc. can be used.

The first precursors of the catalyst bodies obtained in each of the above Examples were referred to as A, B, and C1 sequentially from Example 1 to Example 3, and for comparison, the precursors of the catalyst body obtained by the conventional immersion method, i.e. Ceramic fiber molded body (300imX300mmX20mm
) was directly immersed in a 0.5% by weight chloroplatinic acid aqueous solution for 1 minute, then pulled out and dried at 140°C. The precursor was fired at 500°C using a city gas heating furnace to obtain a catalyst body.

The amount of platinum supported on these catalyst bodies was as shown in Table 1.

The catalyst bodies A, B, C, and F were set in a combustor as shown in FIG. 1, and butane gas was combusted to conduct a comparative test of catalytic combustion.

The results are shown in Figure 2.

In FIG. 1, reference numeral 1 indicates a catalyst body for a combustor, 2 indicates a metal container, and 3 indicates a fuel gas supply port provided at the center of the lower part of the metal container 2.

FIG. 2 shows the relationship between the heat load and the CO concentration in the combustion waste gas.

As is clear from this result, the amount of platinum supported is 3.2 y/rrl in the case of the conventional dipping method, while it is one-eighth of that in the production method of the present invention. It was confirmed that the amount of heat load was increased, and in addition, the amount of CO in the waste gas was reduced.

As is clear from the above results, when used as a catalyst, the catalyst precursor according to the present invention exhibits excellent performance in that the amount of catalyst used is small, the heat load is high, and the amount of CO in waste gas is small. It was confirmed that this was obtained.

As explained above, in the method for producing a catalyst precursor of the present invention, the density of the catalyst is increased only on the surface of the carrier, and the catalyst is uniformly supported, and the amount of catalyst supported is smaller than that of the conventional method. It has the characteristics of being easy to use.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of a flat plate combustor equipped with a combustor catalyst body, Figure 2 is a front view of the catalyst body of the present invention, a structure in which the skeleton is used as a catalyst body, and a conventional catalyst body in Figure 1. It is a graph which shows the relationship between the heat load amount when butane gas is combusted using the flat plate type combustor shown in FIG. In the figure, 1 is a combustion catalyst, 2 is a metal container, and 3 is a fuel gas supply port.

Claims (1)

[Claims] 1. A film made of an organic thermally decomposable substance containing a catalyst is placed on one surface of a carrier, and the surface side of the carrier on which the film is not placed is subjected to a lower pressure than the side on which the film is placed. The first step of the catalyst body is characterized in that the film is brought into close contact with the surface of the carrier, the film is heated and melted, and an organic thermally decomposable substance containing a catalyst is attached only to one surface of the carrier. Body manufacturing method. 2. Apply a solvent that dissolves an organic thermally decomposable substance to the surface of the carrier, and before the solvent dries, place a film made of an organic thermally decomposable substance containing a catalyst on the surface of the carrier, and remove the film. A method for producing a catalyst precursor, which comprises dissolving it in the solvent and depositing an organic thermally decomposable substance containing a catalyst on the surface of a carrier. 3 Apply a solvent that dissolves an organic thermally decomposable substance to only one surface of the carrier, and before the solvent dries, apply a film made of an organic thermally decomposable substance containing a catalyst to only one surface of the carrier. 3. The method for producing a precursor of a catalyst body according to claim 2, wherein the film is dissolved in the solvent, and an organic thermally decomposable substance containing a catalyst is attached to only one surface of the carrier. 4 Applying a solution made of an organic thermally decomposable substance to the surface of the carrier, and before this solution dries, placing a film made of an organic thermally decomposable substance containing a catalyst on the surface of the carrier,
1. A method for producing a precursor for a catalyst body, which comprises adhering the film using the solution as an adhesive, thereby attaching an organic thermal decomposition substance containing a catalyst only to the surface of the carrier. 5. A solution made of an organic thermally decomposable substance is applied to only one surface of the carrier, and before this solution dries, a film made of an organic thermally decomposable substance containing a catalyst is applied to only one surface of the carrier. 5. The method for producing a precursor of a catalyst body according to claim 4, wherein an organic thermally decomposable substance containing a catalyst is attached to only one surface of the carrier by placing the film on the carrier and using the solution as an adhesive.