JP2002145665A - Method for preparing transition metal-containing organic zirconium based compound porous body and transition metal-containing organic zirconium based compound porous body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently produce a transition metal-containing organic zirconium based compound porous body by a method only using inexpensive raw materials, by which waste exerting harmful influence on the environment is hardly produced. SOLUTION: In this method for producing a transition metal-containing organic zirconium based compound porous body, hydrogen peroxide is added to an alcohol solution of zirconium sulfate and a transition metal compound to form precipitates consisting essentially of a zirconium oxide compound and a transition metal comound. Then, the precipitates are foamed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a transition metal which can be used for electrolytes and electrodes of fuel cells, oxygen sensors, oxygen-enriched membranes, heating elements, supports such as biosensors and bioreactors, catalysts and catalyst carriers. The present invention relates to a method for obtaining a porous zirconium oxide-containing compound and a transition metal-containing porous zirconium oxide compound obtained by the method.
More specifically, a method for obtaining a transition metal-containing zirconium oxide-based compound porous body by foaming a transition metal-containing zirconium oxide-based compound by using a clean reagent called hydrogen peroxide water, and a transition metal-containing compound obtained by the production method thereof The present invention relates to a porous zirconium oxide-based compound.

[0002]

2. Description of the Related Art Zirconium oxide (zirconia) and a solid solution or crystal thereof or a porous material containing the same are excellent in heat resistance and corrosion resistance and have high oxygen ion conductivity and high electron conductivity. It is used for electrolytes and electrodes of fuel cells, oxygen sensors, oxygen-enriched membranes, heating elements, supports such as biosensors and bioreactors, catalysts and catalyst carriers.

[0003] In particular, zirconium oxide having a porous structure is expected to be used as a material for various furnaces and mechanical parts because it is lightweight, withstands rapid temperature changes, and has a high soundproofing effect. Further, the zirconium oxide compound-based porous body containing a transition metal while having a porous structure can be applied to an acid-base catalyst, an oxidation catalyst, and the like.

Conventionally, as a method for preparing a porous zirconium oxide-based compound, a substance such as carbon powder is mixed with zirconia powder and molded, and then the carbon powder and the like are burnt and removed in air.
A method of forming a porous structure by leaving a void is mainly used. For example, in Japanese Patent No. 2725732, zirconia powder and methylcellulose or hemicellulose are mixed. In Japanese Patent Application Laid-Open No. 03-257081, zirconia powder and granulated carbon powder are mixed and molded. A method for obtaining a compound molding is shown. Patent 2510044
Discloses a method of adding a zirconia powder, ammonium polyacrylate, ammonium stearate, and water, stirring, foaming, drying, and firing to obtain a porous zirconium oxide-based compound.

[0005]

However, in these methods, a relatively expensive yttria-containing stabilized zirconia or the like is used as a raw material as a zirconia powder, so that the obtained porous zirconium oxide-based compound is expensive. There is a problem that it becomes a thing. When yttria-containing stabilized zirconia requires structural stability at a high temperature of 1000 ° C. or higher, it is a suitable material, but a support for a biosensor or a bioreactor used at around room temperature, a carrier for an enzyme reaction, Or 500
Such a stability is not required for a catalyst or a catalyst carrier used in a reaction at about ℃ to 600 ℃, and a method using less expensive raw materials is required.

In addition, in the conventional method, in order to obtain a pore structure, organic substances must be burned and removed at a high temperature while introducing air, which increases the energy cost, and also causes a bad smell and a large amount of dioxide during combustion. Since carbon or tar is generated, it is not a very preferable method in consideration of environmental problems.

[0007] Furthermore, when a transition metal is contained in these porous bodies, an already established impregnation method, ion exchange method, CVD method, or the like can be applied. It is multi-stage and complicated.

An object of the present invention is to provide a method for efficiently producing a transition metal-containing porous zirconium oxide-based compound by a method using only inexpensive raw materials and hardly generating waste that has a harmful effect on the environment. About.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to achieve the above object, and as a result, have found that a desired zirconium oxide based porous material containing a transition metal can be converted into a zirconium compound and a transition metal compound. The present inventors have found a method for obtaining an alcohol solution and a hydrogen peroxide solution by a simple operation, and have completed the present invention. That is, the method for producing a transition metal-containing zirconium oxide-based compound porous body of the present invention comprises adding an aqueous solution of hydrogen peroxide to an alcohol solution of a zirconium compound and a transition metal compound, and allowing the mixture to stand or reflux to obtain a zirconium oxide compound and The present invention relates to a method for producing a transition metal-containing porous zirconium oxide-based compound, which comprises forming a precipitate containing a transition metal compound as a main component and foaming the precipitate. The present invention also relates to a transition metal-containing zirconium oxide-based compound porous body obtained by the above-mentioned production method.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A transition metal-containing porous zirconium oxide compound can be produced by the present invention, for example, as follows. The zirconium compound in the present invention is not particularly limited, but preferably includes zirconium chloride, zirconium sulfate, zirconyl nitrate, and zirconyl chloride. Zirconium sulfate (Zr (SO ₄ ) ₂ ) is particularly preferably used. The zirconium compound may be an ordinary commercially available one, or may be in the form of a hydrate.

The transition metal compound in the present invention includes:
Although not particularly limited, nitrates and sulfates of various transition metals,
Inorganic salts such as halides such as chlorides, acetates and carbonates,
Also, transition metal compounds having almost any shape such as acetylacetonate salts, alcoholate compounds such as methylate, and organometallic compounds such as carbonyl complex can be used. These transition metal compounds may be used alone or in a mixture of two or more. Cobalt sulfate, nickel sulfate, copper nitrate, nickel nitrate, cobalt nitrate, copper acetate,
Nickel acetate, cobalt acetate, copper chloride, cobalt chloride,
Nickel chloride or the like is preferably used.

In the present invention, the zirconium compound and the transition metal compound are used by dissolving them in an alcohol solvent. For example, in a methanol solution, the total of zirconium and transition metal elements usually has a concentration of 10 ^-2 to 10 ^-1 mol / l. Solutions are preferably used. Even at a concentration lower than this, a similar compound can be obtained if the precipitation time is sufficiently long.

As the alcohol solvent in the present invention,
But not limited to methanol, ethanol,
Nol and lower alcohols are most preferably used. Ma
Use a combination of two or more alcohols
Or a mixture with water. Water in solution
The concentration of is not particularly limited, but is preferably 10^-6-10
^-1Vol% is good.

Although the aqueous hydrogen peroxide in the present invention is not particularly limited, 30 to 35% by weight of aqueous hydrogen peroxide is preferably used. The addition amount of the hydrogen peroxide solution is a molar ratio of the hydrogen peroxide solution: zirconium compound = 1: 10 to 10:
1, preferably 1: 5 to 5: 1. If the amount of the hydrogen peroxide solution is excessively small, a sufficient foaming state cannot be realized, and even if the amount of the hydrogen peroxide solution is excessively increased, the foaming effect is not improved, and the transition metal-containing zirconium oxide is not used. The precipitation amount of the system compound tends to decrease.

[0015] Precipitates can be deposited by allowing the mixed solution to which the hydrogen peroxide solution has been added to stand or reflux. Settle the raw material mixture in a closed container at 0 ° C.
To the boiling point of the solvent, but from 20 ° C to 5
A range of 0 ° C. is preferred. The standing time is from one hour to one week,
Preferably, it is 12 to 48 hours. Reflux can be suitably performed using a flask equipped with a usual reflux condenser. The reflux temperature varies depending on the solvent. Generally, the range of ± 10 ° C. near the boiling point of the solvent is preferable. The processing time is not particularly limited, but is 1 hour to 10 hours, preferably 2 hours to 5 hours. In addition, at the time of precipitation by standing or reflux treatment, or coexist with an organic film such as a porous film,
Silica, alumina, or, for example, cordierite,
When a honeycomb made of stainless steel or the like coexists, it is possible to stably fix the honeycomb on the honeycomb. The precipitate is left at a predetermined temperature and humidity. The temperature at this time is 0 ° C to 80 ° C, preferably 10 ° C to 30 ° C.
Humidity is 0% to 100%, preferably 70% to 99%
It is. Thereafter, vacuum drying is performed for the purpose of removing the solvent.

Next, a foaming treatment is performed. Foaming at room temperature 1
It can be carried out by leaving it to stand for 10 to 10 hours, can be carried out by heating at 100 to 1500 ° C. for 1 to 10 hours, or can be a means such as high-frequency heating by electromagnetic waves. The processing conditions for foaming by high-frequency heating vary depending on the processing amount, but when processing about 10 g using a household microwave oven of about 500 W, heating may be performed for about 0.5 to 30 minutes. . After foaming, a heat treatment may be performed at a temperature of 300 to 1500 ° C. for 1 to 72 hours to stabilize the obtained porous foam.

The present invention will be described below in detail with reference to Examples, but the present invention is not limited to these Examples.

[0018]

Example 1 4.263 g of zirconium sulfate (Zr
(SO ₄ ) ₂ ) · 4H ₂ O) was added to 200 ml of methanol and stirred to dissolve. To this solution, cobalt sulfate (C
further added and stirred oSO ₄ · 7H ₂ O) 0.67g was completely dissolved. This is designated as mixture A. 2.7 g of 30
% Hydrogen peroxide solution was added to 5 ml of methanol. This is called mixture B. Mixture B is added dropwise to mixture A over about 3 minutes. The reaction was stirred at room temperature for another 3 hours.
The precipitate obtained by this operation is separated by filtration, and
It was left for 15 hours under conditions of 5 ° C. and 95% humidity. This was irradiated with microwaves in a microwave oven with an output of 480 W for 5 minutes to foam. A scanning electron micrograph of this foam is shown in FIG. 1, and an ultraviolet-visible spectrum is shown in FIG. Table 1 shows the amounts of zirconium and cobalt.

[0019]

Example 2 4.263 g of zirconium sulfate (Zr
(SO ₄ ) ₂ .4H ₂ O) was added to 200 ml of methanol, and the mixture was stirred and dissolved. Nickel sulfate (Ni
(0.67 g of SO ₄ .7H ₂ 0) was added, and the mixture was further stirred and completely dissolved. This is designated as mixture A. 30% of 4.1 g
Hydrogen peroxide solution was added to 10 ml of methanol. This is called mixture B. Mixture B is added dropwise to mixture A over about 3 minutes. The reaction was stirred at room temperature for another 3 hours.
The precipitate obtained by this operation is separated by filtration, and
It was left for 15 hours under conditions of 5 ° C. and 95% humidity. This was irradiated with microwaves in a microwave oven with an output of 480 W for 5 minutes to foam. A scanning electron micrograph of this foam is shown in FIG. 3, and an ultraviolet-visible spectrum is shown in FIG. Table 1 shows the amounts of zirconium and nickel.

[0020]

Example 3 2.13 g of zirconium sulfate (Zr (S
O ₄ ) ₂ .4H ₂ O) is added to 100 ml of methanol,
Stir and dissolve. To this solution, cobalt sulfate (CoSO
₄ · 7H ₂ 0) was further added and stirred 0.17g was completely dissolved. The solution was adjusted to pH 7 with triethylamine. This is designated as mixture A. 1.36g 30%
Hydrogen peroxide solution was added to 5 ml of methanol. This is called mixture B. Mixture B is added dropwise to mixture A over about 3 minutes. The reaction was stirred at room temperature for a further 3 hours, filtered and
The collected precipitate was left for 15 hours at 15 ° C. and 95% humidity. This was irradiated with microwaves in a microwave oven with an output of 480 W for 5 minutes to foam. A scanning electron micrograph of this foam is shown in FIG. 5, and an ultraviolet-visible spectrum is shown in FIG.
Table 1 shows the amounts of zirconium and cobalt.

[0021]

Example 4 2.13 g of zirconium sulfate (Zr (S
O ₄ ) ₂ .4H ₂ O) is added to 100 ml of methanol,
Stir and dissolve. Nickel sulfate (NiSO
₄ · 7H ₂ 0) was further added and stirred 0.16g was completely dissolved. The solution was adjusted to pH 7 with triethylamine. This is designated as mixture A. 1.36g 30%
Hydrogen peroxide solution was added to 5 ml of methanol. This is called mixture B. Mixture B is added dropwise to mixture A over about 3 minutes. The reaction was stirred at room temperature for a further 3 hours, filtered and
The collected precipitate was left for 15 hours at 15 ° C. and 95% humidity. This was irradiated with microwaves in a microwave oven with an output of 480 W for 5 minutes to foam. The ultraviolet-visible spectrum of this foam is shown in FIG. Table 1 shows the amounts of zirconium and nickel.

[0022]

Example 5 4.26 g of zirconium sulfate (Zr (S
O_Four)_Two・ 4H_TwoO) to 200 ml of methanol,
Stir and dissolve. Copper nitrate (Cu (NO_Three)_Two
・ 3H _Two0) Add 0.29 g and further stir to completely dissolve
I let it. Further, this solution was adjusted to pH 4.
5 was prepared. This is designated as mixture A. 2.7 g of 30
% Hydrogen peroxide solution was added to 5 ml of methanol. this
Mixture B. The mixture B is dropped on the mixture A in about 3 minutes.
Down. The reaction was stirred at room temperature for a further 3 hours and filtered.
Separately, the collected precipitate is subjected to 15 ° C. and 95% humidity conditions.
Left for hours. This is a microwave oven with an output of 480W for 5 minutes
Microwave irradiation and foaming. UV-visible of this foam
The spectrum is shown in FIG. Also, the amount of zirconium and copper
Are shown in Table 1.

[0023]

[Table 1]

[0024]

Comparative Example 1.07 g of zirconium sulfate (Zr (SO
_{4) 2} · 4H ₂ O) was added to dimethylformamide 100 ml, was stirred and heated to dissolve. To this solution was further added and stirred cobalt sulfate _{(CoSO 4 · 7H 2 O)} 0.085g were completely dissolved. To this solution, 0.34 g of hydrogen peroxide was diluted and added with 5 ml of dimethylformamide, and the mixture was further stirred for 3 hours. When this reaction solution was allowed to stand at 35 ° C. for 12 hours, transparent fine crystals were obtained. The crystals were separated from the solution by decantation and left at 15 ° C. and a humidity of 95% for about 1 hour to completely deliquefy and become liquid. This was irradiated with microwaves in a microwave oven with an output of 480 W for 5 minutes, but no good foam was obtained. Also, the obtained white product deliquesces in the air to become liquid. Thus, it can be seen that a good foam as in Examples 1 to 5 cannot be obtained even if a deposit is prepared using a solvent other than alcohol and foaming is performed.

According to the present invention, it is possible to obtain a transition metal-containing zirconium oxide-based compound porous body simply and without a complicated process, and without by-producing substances that pollute the environment. .

[Brief description of the drawings]

FIG. 1 is a diagram instead of an electron micrograph showing the structure of a transition metal-containing zirconium oxide-based compound porous body obtained in the present invention.

FIG. 2 is an ultraviolet-visible absorption spectrum of a porous transition metal-containing zirconium oxide-based compound obtained in the present invention.

FIG. 3 is a diagram instead of an electron micrograph showing the structure of a porous body of a transition metal-containing zirconium oxide-based compound obtained in the present invention.

FIG. 4 is an ultraviolet-visible absorption spectrum of the transition metal-containing zirconium oxide-based compound porous body obtained in the present invention.

FIG. 5 is a drawing instead of an electron micrograph showing the structure of the transition metal-containing zirconium oxide-based compound porous body obtained in the present invention.

FIG. 6 is an ultraviolet-visible absorption spectrum of the transition metal-containing zirconium oxide-based compound porous body obtained in the present invention.

FIG. 7 is an ultraviolet-visible absorption spectrum of the transition metal-containing zirconium oxide-based compound porous body obtained in the present invention.

FIG. 8 is an ultraviolet-visible absorption spectrum of the porous transition metal-containing zirconium oxide-based compound obtained in the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) H01M 4/88 H01M 4/88 T 8/02 8/02 Z 8/12 8/12 (72) Inventor Takashi Backguchi 8-1 Goi South Coast, Ichihara City, Chiba Prefecture Ube Industries, Ltd. Polymer Research Laboratory F-term (reference) 4G019 FA15 GA04 4G031 AA12 AA22 AA23 BA01 BA21 BA27 CA09 GA01 4G048 AA01 AA06 AA07 AC06 AC08 AD01 AE05 5H018 AA06 AS02 BB16 DD01 EE12 5H026 AA06 BB08 BB10 EE12

Claims (3)

[Claims] 1. A transition metal-containing zirconium oxide-based system, comprising: depositing a precipitate from a mixture of a solution in which a zirconium compound and a transition metal compound are dissolved in alcohol and adding hydrogen peroxide solution; and foaming the precipitate. A method for producing a compound porous body. 2. The method according to claim 1, wherein the zirconium compound is zirconium sulfate. 3. A transition metal-containing zirconium oxide-based compound porous material obtained by the production method according to claim 1.