JPH0352641A - Production of inorganic porous body carrying catalyst - Google Patents

Abstract

PURPOSE:To obtain a carrier which enhances catalytic function by using a swellable laminer compd. which is dried and in a swelled state with inorg. pillar material inserted thereinto among layers. CONSTITUTION:First, the swellable inorg. laminer compd. 1 as the main material is mixed with a solvent such as water and kneaded as required to obtain a swelled state containing the solvent among layers. A cation-type inorg. compd. is added into an inorg. compd. in a colloid state to prepare a solution containing inorg. pillar material 2 the surface of which is modified with the cation-type inorg. compd. This solution is added to the swelled inorg. laminer compd. 1 to insert the inorg. pillar material into the interlayer spaces 1a of the inorg. laminer compd. 1. Then this compd. is dried to obtain the inorg. porous body, which can be used as a carrier of catalyst. Since the obtd. carrier effectively carries the catalyst, the catalytic effect can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a catalyst-supported inorganic porous body in which a catalyst is supported on the inorganic porous body.

[Conventional technology]

Conventionally, catalyst-supported porous alumina is used as a catalyst-supported inorganic porous body. This material is obtained by stirring porous alumina powder (particle size of about 1 to several nanometers) while dropping an aqueous solution containing a catalyst (for example, Pt), followed by drying and burning.

[Problem to be solved by the invention]

Recently, it has been strongly desired to further enhance the catalytic function of the above-mentioned inorganic porous materials.

An object of the present invention is to provide a method for manufacturing a catalyst-supported inorganic porous body that can effectively support a catalyst so that the catalyst function is further enhanced.

[Means to solve the problem]

In order to solve the above problems, the method for producing a catalyst-supported inorganic porous body according to claims 1 to 11 uses a porous body obtained by drying a swellable layered compound in a swollen state with an inorganic pillar material inserted between the layers, A catalyst is supported on this porous body.

The swellable layered compound is preferably dried in a supercritical state (supercritical drying) as in the invention of claim 2, but other drying methods such as hot air drying or freeze drying may also be used. Good too.

Before supporting the catalyst, it is preferable to once burn the porous body as in the third aspect of the invention.

As the inorganic pillar material, for example, at least one of a colloid, a do-like inorganic compound, and a hydrolyzate of a metal alcoholate is used.
In this case, specifically, as in the invention of claim 5, as the colloidal inorganic compound, S ion + Sbt
Ox, Fe, Ox, ArmO@. T t
Ox, and at least one selected from the group consisting of ZrOz, and as the metal alcoholate to be a hydrolyzate, Si(OR)4. /l! (OR)W,
and at least one selected from the group consisting of Ge(OR)4.

The inorganic pillar material may be used after its surface has been modified with at least one of a cationic inorganic compound and a metal alcoholate. In this case, specifically, as in the invention according to claim 7, the cationic inorganic compound is a titanium-based compound. Zirconium compounds, hafnium compounds, iron compounds, copper compounds, chromium compounds, nitrous compounds,
Zinc-based compounds. Aluminum compounds. At least one selected from the group consisting of manganese compounds, phosphorus compounds, and boron compounds is mentioned, and the metal alcoholate used for modification includes Ti(OR)4, Z
r (OR)4, PO (OR)2, and B
(OR), at least one selected from the group consisting of.

Furthermore, as in the eighth aspect of the invention, organic pillars may be inserted between the layers of the swellable layered compound together with the inorganic pillar material. In this case, the organic pillars include water-soluble polymer compounds and quaternary ammonium salts, but also include higher fatty acids, amphoteric surfactants, choline compounds, and the like. These organic pillars may be used alone or in combination.

More specifically, as in the invention described in claim 9, the water-soluble polymer compound for organic pillars is polyvinyl alcohol, polyethylene glycol. Polyethylene oxide, methylcellulose. Carpoxymethyl cellulose (C
MC), polyacrylic acid, sodium polyacrylate, polyacrylamide, and polyvinylpyrrolidone, and may be used alone or in combination. .

There are various possible quaternary ammonium salts and higher fatty acids, among which octadecyl group,
Those having at least one group selected from the group consisting of a hexadecyl group, a tetradecyl group, and a dodecyl group are preferred. Specifically, as the quaternary ammonium salt, octadecyltrimethylammonium salt. Dioctadecyldimethylammonium salt 9 Hexadecyltrimethylammonium salt, dihexadecyldimethylammonium salt, tetradecyltrimethylammonium salt, ditetradecyldimethylammonium salt, etc., and higher fatty acids such as valmitic acid (hexadecyl acid), stearic acid ( octadecyl acid), olein i%t (cis
-9-octadecenoic acid), linoleic acid (cis-9,
cis-1 2-octadecadienoic acid) and the like may be used alone or in combination of two or more.

Various choline compounds can be considered, for example,
(HOCHt CH*N (CHI)R)”○H
- (i.e. C4 H.%No.), CI H. ．． C
ANO, C% Hl4NOC. H% 04, C&H
l4NOC= Hv O,, Cs HI4NOC- H
．． oy is preferred, and each is used alone or in combination of two or more.

Various types of amphoteric surfactants can be considered, but among them, those whose cation moiety is an aliphatic amine type and whose anion moiety is a carboxyl group, sulfate ester group, sulfone group, or phosphate ester group are considered as amphoteric surfactants. Those having at least one group selected from these are preferred.

As the catalyst to be supported, platinum, ruthenium, palladium. At least one selected from the group consisting of gold and vanadium oxide may be mentioned, while examples of the swelling layered compound include Na-montmorillonite, Ca-montmorillonite. Synthetic hecl light. Synthetic smectite (
For example, a 3-octahedral one can be mentioned. Examples of the 3-octahedral type include synthetic saponite, Na-hectorite, Si-hectorite, Na-teniolite, Li-teniolite, acid clay, and phyllosilicate minerals such as synthetic mica. (here,
They may be either natural products or synthetic products, and may be used alone or in combination of two or more. In addition,
When using a poorly swellable inorganic layered compound such as Ca-montmorillonite or acid clay, it is necessary to apply strong shearing force due to crosstalk or the like during swelling.

It goes without saying that the compounds and treatments used in this invention are not limited to those exemplified above. Next, the method for manufacturing the catalyst-supported inorganic porous material according to the present invention will be explained in more detail step by step.First, the swellable inorganic layered compound as the main material is mixed with a solvent such as water, and further, if necessary, and knead to form a state in which the solvent is impregnated between the layers (swelled state). The interlayer spacing of the inorganic layered compound during swelling is, for example, about 150 in the case of clay minerals.

As the solvent used for swelling the inorganic layered compound, polar solvents such as water, ethanol, methanol, DMF (dimethylformamide), DMSO (dimethyl sulfoxide), and acetone can be used alone or in combination of two or more. Generally, water is often used.

On the other hand, a cationic inorganic compound is added to a colloidal inorganic compound to prepare a solution containing a colloidal inorganic compound (inorganic pillar material) whose surface is modified with the cationic inorganic compound, and this solution is swollen. The inorganic pillar material is added to and mixed with the layered inorganic compound, and the inorganic pillar material is inserted between the layers of the inorganic layered compound. Subsequently, a quaternary ammonium salt (organic pillar) is further added and mixed to insert the organic pillar between the layers of the inorganic layered compound. The temperature at which the inorganic pillar material and organic pillar material are added and mixed is not particularly limited, but is approximately 60 to 70°C. The mixture thus obtained is centrifuged to form a gel, and then oriented into a plate using a spatula or the like.

Then, this plate-like body is dried.

For example, when drying in a supercritical state, do the following. Of course, drying may be started from the mixed liquid state.

Here, the supercritical state includes not only the case where the critical point is exceeded but also the case where the state is exactly at the critical point. A specific method for drying in a supercritical state is, for example, by directly heating and pressurizing the solvent contained in the swellable layered inorganic compound, such as water contained between the layers, to reach a state above its critical point. There is also a method of removing the solvent and drying it in a state where the critical point of water is the critical temperature 3 7
4. The extremely high values of 2°C and critical pressure of 217.6 atm necessitate the use of an autoclave or the like. In order to avoid this, it is necessary to replace the water in the swellable layered compound with, for example, ethanol, and then add carbon dioxide.While gradually replacing ethanol with carbon dioxide, the two components of carbon dioxide and ethanol are added. The supercritical state may be brought about by heating and pressurizing the system to a temperature and pressure above the critical point of the system. After the ethanol has been extracted and removed, the drying process is completed when the temperature and pressure are returned to normal. In this case, it is also possible to send carbon dioxide above the critical point into the system for substitution.

Note that fluids that can be used as solvents are not limited to those mentioned above. There are various substances that can be made into supercritical fluids within a practical range, such as ethanol, methanol, carbon dioxide, difluoromethane, and ethylene. For reference, critical conditions for major fluids are shown in Table I.

Table 1 This supercritical drying prevents the condensation of inorganic layered compounds and the aggregation of inorganic layered compounds, and while maintaining the structure before drying, the petal-like or cicada-like feather-like material becomes a card house-like or sponge-like material. An inorganic porous body is obtained, which is a collection of aggregates. Therefore, when supercritical drying is used, a porous body with a larger pore volume can be obtained than when hot air drying or freeze drying is used. In other words, as shown in Fig. 1, the inorganic layered compound 1 has an inorganic layer 2 inserted between the layers 1a, and not only is there a sufficient gap between the layers 1, but also between the inorganic layered compounds 1. Sufficient voids exist, resulting in a very large pore volume.

Usually, a burning precept is performed after drying. This burning stabilizes the structure of the inorganic pores. Furthermore, if organic pillars remain in the porous body, the remaining organic pillars can be removed by burning.

Next, the process moves on to the catalyst supporting step, and the present invention is characterized in that the catalyst is supported on the inorganic porous body thus obtained. A solution containing a catalyst substance is added dropwise to the burnt inorganic porous body using a mortar or the like and stirred to carry the catalyst.

For example, an aqueous solution containing Hz P t Cla .6 Hz O is added dropwise and stirred. Thereafter, it is dried and calcined at about 450° C. in an H gas stream to obtain a Pt-supported inorganic porous body. By performing the burning in this H8 gas flow, the catalytic function becomes more stable and more effective. In the obtained catalyst-supported inorganic porous material,
As shown in FIG. 2, the catalysts 3 are supported between the layers 1a of the inorganic layered compounds 1 and between the inorganic layered compounds 1 in a manner that allows them to function effectively.

[For production]

In the method for producing an inorganic porous body of the present invention, a catalyst is effectively supported in a porous body obtained by drying a swellable layered compound in a swollen state with an inorganic pillar material inserted between the layers. be able to. Inorganic pillars can also be used as catalysts depending on the type of inorganic pillars selected.

When using a porous material that dries a swellable layered compound in a supercritical state, it is possible to support the catalyst in a way that allows it to function more effectively. Ru.

〔Example〕

Hereinafter, specific examples and comparative examples of the present invention will be described.

Example 1 - Ethanol and 2N hydrochloric acid were added to metal alcoholate St(QC■H,)4 to perform a hydrolysis reaction, and further T
i (OCm H-) 4 dissolved in 2N hydrochloric acid is added to make an inorganic pillar material, and this is added to a 0.8 wt% aqueous solution of Na-montmorillonite (Kunipia F manufactured by Kunimine Industries Co., Ltd.) swollen with water. was added to cause a reaction. The reaction temperature and reaction time were 60'C and 1.5 hours. After the reaction, washing with water and centrifugation were repeated several times, and the porous material was oriented into a plate shape with a spatula, dried with hot air (80°C, 8 hours), and then burned at 500°C for 4 hours to form a porous body. Obtained. Next, the obtained porous body was crushed lightly in a mortar, and an aqueous solution of HyoptClm .6Hzo was added dropwise thereto while stirring to support the catalyst (Pt). This was followed by drying (80'C, 8 hours) and then calcination in a stream of H8 (
450'C for 4 hours) to obtain an inorganic porous body supporting Pt (catalyst). The ratio (weight ratio) of each component in this inorganic porous material is Na-montmorillonite: SiO*:
TiOt:Pt=1:0. 6: 0.06:
It was 0.05. Example 2 - S t (O Cz
Ethanol and 2N hydrochloric acid were added to Hs) a to perform a hydrolysis reaction, and then Ti (QC.H-) 4 was added to 2
Add the material dissolved with N-hydrochloric acid to make inorganic pillar material.
This is Na-montmorillonite that is swollen with water.
(Kunipia F manufactured by Kunimine Kogyo Co., Ltd.) 0; 8wt%
The mixture was added to an aqueous solution for reaction.

The reaction temperature and reaction time were 60'C and 1.5 hours. After the reaction, octadecyltrimethylammonium chloride (NOF NL Nifsan Cation AB), which is a quaternary ammonium salt, was further added and reacted as an organic pillar. Reaction time and reaction temperature were 40 minutes, 6
It was set to 0'C.

Subsequently, washing with water and centrifugation were repeated several times, oriented into a plate shape with a spatula, dried with hot air (80°C, 8 hours), and then burned at 500°C for 4 hours to obtain a porous body.

The porous body thus obtained was lightly crushed in a mortar, and an aqueous solution containing HyoPtCNa.6HtO was added dropwise to the porous body and stirred to support Pt (catalyst). Thereafter, it was dried (80°C, 8 hours) and then burned in an H gas stream (450°C, 4 hours) to obtain an inorganic porous body supporting Pt (catalyst). The proportion (weight ratio) of each component in the body is Na-montmorillonite: St
ow: Tilt:Pt=1:0.6:0.06:1
:0.05.

Example 3 - In Example 1, after the insertion reaction of the inorganic pillar material, washing with ethanol and centrifugation were repeated several times, and then the material was oriented in a plate shape with a spatula, and carbon dioxide (Cot), which has a relatively low critical point, was ) at 40°C and 80 atm.
Supercritical drying over time? A PT-supported inorganic porous material was obtained in the same manner as in Example 1, except that the material was heated and then baked at 500° C. for 4 hours. The ratio (weight ratio) of each precept in this inorganic porous material is Na-montmorillonium-:SiO
■:TiOa:Pt= 1: 0.6: 0.0
6:0.05.

Example 4 A colloidal inorganic compound, S iO t sol (Snowtex
i (OCs Hy ) 4 dissolved in 2N hydrochloric acid was added to make an inorganic pillar material, and this was mixed with 0.8 wt% of Na-montmorillonite (Kunipia F manufactured by Kuni Tsune Kogyo Co., Ltd.) swollen with water. The mixture was added to an aqueous solution for reaction.

The reaction temperature and reaction time were 60°C and 1.5 hours. After the reaction, washing with ethanol and centrifugation were repeated several times, oriented into a plate shape with a spatula, and heated at 40°C and 80 atm while adding carbon dioxide (CO.), which has a relatively low critical point.
After supercritical drying over a period of time, it was burned at 500° C. for 4 hours.

Lightly crush the porous material obtained in this way in a mortar? An aqueous solution of R u C l m .3H■O was added dropwise to this while stirring to support Ru (catalyst). Thereafter, it was dried (80° C., 8 hours) and then calcined in a H3 stream (450° C., 4 hours) to obtain an inorganic porous body supporting Ru (catalyst). Each certain proportion (weight ratio) in this inorganic porous body is Na-montmorillonite: Si
O*:TiOt:Ru=l: 0. 6:0.06
:0.05. Example 5 - Metal alcoholate S i (O Cm Hs
) 4 was added with ethanol and 2N hydrochloric acid to perform a hydrolysis reaction, and further T i C la (4a+ol/1
) was added to prepare an inorganic pillar material, and this was added to a 0.8wL% aqueous solution of Na-montmorillonite (Kunivia F, manufactured by Kunishine Kogyo Co., Ltd.) in a swollen state with water.

The reaction temperature and reaction time were 60°C and 1.5 hours. After this reaction, a quaternary ammonium salt, octadecyltrimethylammonium chloride (Ninsan Cation AB, manufactured by NOF Corporation), was further added as an organic pillar for reaction. The reaction time and temperature are 40 minutes and 60°C. After the reaction, washing with ethanol and centrifugation were repeated several times, and the mixture was oriented into a plate shape using a filter, and was heated at 40°C and 80 atm for 8 hours while adding carbon dioxide (CO), which has a relatively low critical point. After supercritical drying, it was fired at 500°C for 4 hours.

The porous body thus obtained was lightly crushed in a mortar, and an aqueous solution containing p d C 1 t was added dropwise thereto while stirring to support Pd (catalyst). After this, dry (8
0°C, 8 hours), then calcined in H, air flow (450°C).
℃ for 4 hours> to obtain an inorganic porous body supporting Pd (catalyst). Ratio of each precept (weight ratio) in this inorganic porous material
is Na-monmolyte: SiOt:TiOx:
Pd=1:0. 6:0. 0 6:0.
It was 05.

Example 6 In Example 3, HxPtC1. An Au (catalyst) supported inorganic porous body was obtained in the same manner except that an aqueous solution containing HAuCf4 .4H,0 was used instead of an aqueous solution containing .6H,○. The ratio (weight ratio) of each precept in this inorganic porous body is Na-montmorillonite: S
iOz:TiOg:Au=1:0. 6:0
．． o6: o. It was o5.

- Example 7 - In Example 3, Hz P t C Its ・6
Instead of an aqueous solution containing H80, H A u C j!
4 ・4H. An inorganic porous body supporting Au (catalyst) and Pd (catalyst) was obtained in the same manner except that an aqueous solution containing O and P d C l m was used. The ratio (weight ratio) of each precept in this inorganic porous body is Na-montmorillonite:SiOz:TiOz:Au:Pd=1
: 0.6 : 0.0 6:0.05:0.05.

Comparative Example 1 A lightly crushed r-Alz Os porous body (inorganic porous) was
-riptcz・6H. Pt was supported by stirring an aqueous solution containing Pt0 dropwise, followed by drying (80°C for 8 hours) and further burning in an H8 stream (450°C for 4 hours).
A (catalyst) supported inorganic porous body was obtained. The ratio (weight ratio) of each component in this inorganic porous material is γ-AI. ○s:
Pt=1: 0.05.

The specific surface area and pore volume of each of the catalyst-supported inorganic porous bodies of Examples 1 to 7 and Comparative Example 1 were measured. The specific surface area and pore volume were investigated using the BET method in the nitrogen adsorption method. The measurement results are shown in Table 1.

Further, the catalyst-supported inorganic porous bodies of Examples and Comparative Examples had a deodorizing function, and the degree of the deodorizing function was investigated as follows. Fill the container with NH. In addition to allowing the air containing (120 ppm) to flow, a catalyst-supported inorganic porous material is placed inside the container, and the NH of the air coming out of the container is
．． The concentration was measured using an ammonia detection tube. In addition, in the case of the catalyst-supported porous bodies of Examples 1 to 5 and Comparative Example, the porous bodies were heated to a temperature of 150°C. In the case of the catalyst-supported porous bodies of Examples 6 and 7, the porous bodies were not heated.

The catalyst-supported inorganic porous bodies of Examples 1 to 7 all exhibited superior deodorizing effects compared to those of the comparative examples, and each catalyst was supported so as to effectively exhibit its catalytic function. I can clearly see that there are. As seen in Examples 6 and 7,
It can be seen that the catalyst-supported inorganic porous material exhibits an excellent deodorizing effect without being heated, and is therefore easy to use and highly practical.

〔Effect of the invention〕

As described above, the production method of the present invention uses an inorganic porous material obtained by drying a swellable layered compound in a swollen state with inorganic pillars inserted between the layers, and supports a catalyst on the inorganic porous material. Therefore, it is possible to obtain an excellent catalyst-supported inorganic porous material in which the catalyst is effectively supported so that the catalyst can exhibit sufficient catalytic function.

[Brief explanation of drawings]

FIG. 1 is a schematic illustration of an inorganic porous body used in the production method of the present invention, and FIG. 2 is a schematic illustration of a catalyst-supported inorganic porous body obtained by the production method of the present invention. 1... Inorganic layered compound 1 a... Interlayer 2... Inorganic pillar 3... Catalyst

Claims (1)

[Scope of Claims] 1. When supporting a catalyst on an inorganic porous body, the inorganic porous body is made by drying a swellable layered compound in which an inorganic pillar material is inserted between the layers in a swollen state. A method for producing a catalyst-supported inorganic porous material. 2. The method for producing a catalyst-supported inorganic porous material according to claim 1, wherein the drying of the swellable layered compound is supercritical drying. 3. The method for producing a catalyst-supported inorganic porous body according to claim 1 or 2, wherein the porous body is fired before supporting the catalyst. 4. The method for producing a catalyst-supported inorganic porous material according to any one of claims 1 to 3, wherein the inorganic pillar material is at least one of a colloidal inorganic compound and a hydrolyzate of a metal alcoholate. 5 The colloidal inorganic compound is SiO_2, Sb_3O
_2, Fe_2O_2, Al_2O_2, TiO_2,
and a metal alcoholate which is at least one selected from the group consisting of ZrO_2 and becomes a hydrolyzate,
Si(OR)_4, Al(OR)_2, and Ge(
5. The method for producing a catalyst-supported inorganic porous material according to claim 4, wherein the catalyst is at least one selected from the group consisting of OR)_4. 6. The method for producing a catalyst-supported inorganic porous material according to any one of claims 1 to 5, wherein the inorganic pillar material has a surface modified with at least one of a cationic inorganic compound and a metal alcoholate. 7 The cationic inorganic compound is a titanium-based compound, a zirconium-based compound, a hafnium-based compound, an iron-based compound, a copper-based compound, a chromium-based compound, a nickel-based compound, a zinc-based compound, an aluminum-based compound, a manganese-based compound, a phosphorus-based compound compound, and at least one selected from the group consisting of boron-based compounds, and the metal alcoholate used for modification is Ti(OR)_4, Zr(OR)_4,
The method for producing a catalyst-supported inorganic porous body according to claim 6, wherein the catalyst is at least one selected from the group consisting of PO(OR)_2 and B(OR)_3. 8. Any of claims 1 to 7, wherein an organic pillar is inserted between the layers of the swellable layered compound together with the inorganic pillar material, and the organic pillar is at least one of a water-soluble polymer compound and a quaternary ammonium salt. A method for producing a catalyst-supported inorganic porous material according to claim 1. 9 The water-soluble polymer compound is polyvinyl alcohol, polyethylene glycol, polyethylene oxide, methylcellulose, carboxymethylcellulose, polyacrylic acid, sodium polyacrylate, polyacrylamide,
and at least one selected from the group consisting of polyvinylpyrrolidone, and the quaternary ammonium salt has at least one group selected from the group consisting of octadecyl group, hexadecyl group, tetradecyl group, and dodecyl group. The method for producing a catalyst-supported inorganic porous material according to claim 8. 10. The method for producing a catalyst-supported inorganic porous material according to any one of claims 1 to 9, wherein the catalyst is at least one selected from the group consisting of platinum, ruthenium, palladium, gold, and vanadium oxide. 11 The swelling layered compound is Na-montmorillonite,
Ca-montmorillonite, acid clay, 3-octahedral synthetic smectite, Na-hectorite, Li-hectite, Na-teniolite, Li-teniolite, and
The method for producing a catalyst-supported inorganic porous material according to any one of claims 1 to 10, wherein the catalyst is at least one selected from the group consisting of synthetic mica.