JPH0733410A - Production of hydrogen peroxide - Google Patents

Abstract

PURPOSE:To obtain a high concn. hydrogen peroxide in high selectivity without the presence of a halogen ion by using a platinum group metal catalyst modified with a specified metallic element and allowing oxygen to react catalystically with hydrogen in a reaction medium. CONSTITUTION:This reaction catalyst is obtained by depositing a platinum group metal catalyst which is obtained by modifying 1-10wt.% platinum group element such as palladium and platinum per catalyst carrier with more than 1/2 times, by wt., at least one kind of element selected among lead, zinc, gallium and bismuth on the catalyst carrier such as titanium oxide. The acidic aq. soln. which is obtained by adding the inorg. acid such as sulfuric acid, nitric acid, phosphoric acid which does not contain a halogen ion is used as the reaction medium, and >=1g reaction catalyst per 1l reaction medium and a stabilizing agent in need are added to the reaction medium, and the gaseous mixture of gaseous hydrogen, oxygen and nitrogen on volume base is fed into an autoclave, and the hydrogen peroxide is produced by allowing to react under agitation at a pressure of 3-150kg/cm<2>.G and a temp. of 0-50 deg.C for 30min-6hr.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an improved process for catalytically reacting oxygen and hydrogen in a reaction medium to produce hydrogen peroxide. More specifically, the present invention relates to a method for producing hydrogen peroxide by reacting oxygen and hydrogen in the presence of a platinum group catalyst in a reaction medium containing no cocatalyst such as halogen ions.

[0002]

2. Description of the Related Art Currently, the main method of industrially producing hydrogen peroxide is an autoxidation method using alkylanthraquinone as a medium. The problem with this method is that it requires many steps such as reduction of alkylanthraquinone, oxidation, extraction and separation of the produced hydrogen peroxide, purification and concentration, which complicates the process, resulting in equipment costs and operating costs. Is large. Further, there are problems such as loss due to deterioration of alkyl anthraquinone and deterioration of activity of the reduction catalyst. In order to improve these problems, a manufacturing method other than the above manufacturing method has been attempted, and one of them is
There is a method of producing hydrogen peroxide directly from oxygen and hydrogen using a catalyst in a reaction medium. For example, a method of producing hydrogen peroxide from oxygen and hydrogen using a platinum group metal as a catalyst has been proposed, and it is known that a considerably high concentration of hydrogen peroxide is produced (for example, Japanese Patent Publication No. No. 47121,
JP-B-55-18646, JP-B-1-23401, JP-A-63-15600
No. 5). In each of these, an aqueous solution in which an acid or an inorganic salt is dissolved is used as a reaction medium. In particular, it has been shown that by including a halogen ion in the reaction medium, the activity of the catalyst is suppressed, the selectivity of the hydrogen peroxide generation reaction is significantly improved, and the concentration of hydrogen peroxide obtained is increased. JPA
63-156005 discloses a method for producing hydrogen peroxide from oxygen and hydrogen under pressure in a sulfuric acid acidic aqueous solution using a platinum group catalyst by coexisting halogen ions such as bromide ion in the aqueous solution. , Shows that high concentration hydrogen peroxide can be selectively produced. That is, in the conventional technique, in the method of producing hydrogen peroxide by catalytically reacting oxygen and hydrogen in a reaction medium, in order to obtain hydrogen peroxide with a high selectivity, it is necessary to use a halogen ion or the like. It was necessary to use a catalyst.

[0003]

DISCLOSURE OF THE INVENTION In a method for producing hydrogen peroxide by catalytically reacting oxygen and hydrogen in a reaction medium, the conventional known technique is to obtain a practical concentration of hydrogen peroxide. It was necessary to coexist an acid and a halogen ion in the reaction medium. Thus, when a high concentration of halogen ions is present in the acidic reaction medium, the material of the equipment that can be used in its handling is limited, and as a result,
There is an economical problem because an expensive corrosion-resistant reaction container is required. Further, there is a problem that the platinum group metal, which is the active component of the catalyst, is eluted in the reaction medium. In particular, the amount of platinum group metal eluted increases in proportion to the concentration of halogen ions. The elution of the platinum group metal component causes a decrease in catalyst activity and a decrease in catalyst life, and becomes a serious economic problem when hydrogen peroxide is produced by an industrial continuous operation. As described above, the conventional technique of carrying out the reaction in the presence of halogen ions has various economic problems including the necessity of a purification step for removing halogen ions from the product.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention used a platinum group catalyst in the presence or absence of an inert gas such as nitrogen, which does not adversely affect the present reaction, to produce oxygen and hydrogen in a reaction medium. In the method of producing hydrogen peroxide by reacting catalytically, as a result of continuing the examination of the production method for obtaining a high concentration of hydrogen peroxide in a reaction medium containing no halogen ion, lead, zinc, gallium and bismuth It was found that by using a platinum group metal catalyst modified with at least one element selected from the above, a high concentration of hydrogen peroxide can be obtained using an acidic aqueous solution containing no halogen ion as a reaction medium.

That is, in the present invention, the platinum group metal is lead, zinc,
Using a catalyst modified with at least one element selected from gallium and bismuth, and using an acidic aqueous solution containing no halogen ions as a reaction medium, in the presence or in the presence of an inert gas such as nitrogen, which does not adversely affect this reaction. The present invention provides a method for producing hydrogen peroxide, which makes it possible to obtain a high concentration of hydrogen peroxide by reacting catalytically in the presence of hydrogen peroxide. INDUSTRIAL APPLICABILITY The present invention has solved the problems of the material of the reaction vessel and the deterioration of catalytic activity due to the coexistence of halogen ions.

In the present invention, a catalyst in which a platinum group element is supported on a carrier is used. As the platinum group element, specifically, palladium, platinum or the like can be used alone or as a mixture or alloy. Further, it is also possible to use a mixture or alloy containing ruthenium, osmium, rhodium, iridium or gold, which is mainly composed of them. Particularly, a catalyst containing palladium as a main component is preferably used.

The method for preparing the catalyst in the present invention is not particularly limited, but it is preferable to simultaneously add a salt of a platinum group element and a salt of lead, zinc, gallium or bismuth to a carrier used for ordinary catalyst preparation. After carrying, it is baked,
A method of preparing a catalyst by performing a reduction treatment can be adopted. In addition, lead, zinc, and
The catalyst may be prepared by carrying a salt of gallium or bismuth and then calcining and carrying out a reduction treatment. There is no particular limitation as a carrier used for the catalyst of the present invention, and any catalyst carrier can be used. Among them, a carrier having a large mechanical strength or specific surface area of the catalyst, that is, aluminum oxide, silicon oxide, Zirconium oxide,
Titanium oxide, zeolite, silica-alumina, activated carbon,
Adsorption resins and ion exchange resins are preferred.

Examples of the salt of the platinum group element include salts or complexes of palladium, platinum, ruthenium, osmium, rhodium, iridium or gold, preferably, nitrates, hydrochlorides or acetates of palladium or gold, or palladium. Alternatively, a gold tetraammine complex is used. The loading amount of the platinum group element is usually, with respect to the carrier,
It is 0.1 to 10% by weight. Examples of the lead, zinc, gallium or bismuth salt include lead, zinc, gallium or bismuth nitrate, hydrochloride, sulfate or acetate. The amount of lead, zinc, gallium or bismuth in the modified platinum group metal catalyst used in the present invention is at least 1/2 times the weight of the platinum group metal, preferably at least 10 times the weight of the platinum group metal.

The amount of the catalyst used in the production of hydrogen peroxide of the present invention is usually 1 gram or more per 1 liter of the reaction medium, and it can be used in the form of a slurry. Water is usually used as the reaction medium in the production of hydrogen peroxide of the present invention, but an acidic aqueous solution containing an inorganic acid containing no halogen ion such as sulfuric acid, nitric acid or phosphoric acid is preferably used. Known stabilizers for preventing decomposition of hydrogen peroxide (eg, aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), pyrophosphoric acid, or salts thereof. It is also preferable to add to the reaction medium: The reaction conditions in the production of hydrogen peroxide of the present invention are usually a reaction pressure of 3 to 150 kg / cm ² · G, a reaction temperature of 0 to 50 ° C., and a reaction time of 30 minutes. It is carried out under the condition of ~ 6 hours.

[0010]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. In Examples and Comparative Examples, the gas composition was analyzed by gas chromatography, and the concentration of hydrogen peroxide in the solution was measured by titration with a potassium permanganate solution under sulfuric acid acidity. Example 1 A catalyst was prepared by the following method. That is, 10 g of commercially available titanium oxide (TAYCA Corporation, anatase type)
50 ml of commercially available lead nitrate (manufactured by Komune Chemical Co., Ltd.) in a suspension of 100 ml of water.
A mixed solution of 50 ml of an aqueous solution dissolved in milliliter of water and a diluted solution of a palladium nitrate solution (manufactured by Ishifuku Metal Industry Co., Ltd., 1 g-Pd / liter) was added dropwise. After the dropping is completed, this suspension is evaporated and dried on a hot plate,
Further, it was dried in a dryer at 110 ° C. for 24 hours. Then, it was calcined in an air stream at 500 ° C. for 2 hours and then reduced in a hydrogen stream at 120 ° C. for 1 hour to obtain a catalyst. The following operation was performed as a reaction method for directly producing hydrogen peroxide from oxygen and hydrogen. In a glass container having an inner volume of 65 ml, 10 g of an aqueous solution prepared so as to have a sulfuric acid content of 0.1 mol / liter was placed. To this aqueous solution, 50 mg of the supported palladium catalyst prepared as described above was added, and the glass container was placed in an autoclave having a volume of 100 ml. Hydrogen gas was 3.5% by volume, oxygen gas was 35% by volume,
After performing a pressure test with a mixed gas of nitrogen gas having a composition of 61.5% by volume, 50 kg / cm 2 with a gas of the same composition
Until ² · G pressurized. 2,000 while keeping the temperature at 10 ℃
The mixture was stirred at 0 rpm for 1 hour. After completion of stirring, the hydrogen peroxide concentration in the aqueous solution was 0.62% by weight, and the hydrogen selectivity was 94%. The hydrogen selectivity was calculated by the following formula.

[Equation 1] Hydrogen selectivity (%) = [(mol amount of hydrogen peroxide produced by reaction) / (mol amount of theoretical production of hydrogen peroxide calculated from the amount of hydrogen consumed)] x 100

Example 2 When preparing a catalyst, commercially available titanium oxide (TAYCA
Catalyst preparation and reaction were performed in the same manner as in Example 1 except that 10 g of commercially available zirconium oxide (manufactured by Komune Chemical Co., Ltd.) was used instead of 10 g of anatase type manufactured by Co., Ltd. After stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.56% by weight, and the hydrogen selectivity was 51.
%Met.

Example 3 Similar to Example 2, except that 6.80 g of commercially available zinc nitrate (manufactured by Komune Chemical Co., Ltd.) was used in place of 2.40 g of commercially available lead nitrate in preparing the catalyst. The catalyst was prepared and reacted by the operation. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.44% by weight, and the hydrogen selectivity was 64%.

Example 4 In preparing the catalyst, a commercially available aluminum oxide (Mizusawa Chemical Co., Ltd.) was used as a carrier instead of the commercially available zirconium oxide.
Catalyst preparation and reaction were carried out by the same operations as in Example 3, except that the active alumina produced was used. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.22% by weight, and the hydrogen selectivity was 23%.

Example 5 Catalyst preparation and reaction were carried out in the same manner as in Example 3 except that commercially available silicon dioxide (manufactured by Mizusawa Chemical Co., Ltd.) was used as a carrier instead of commercially available zirconium oxide in the preparation of the catalyst. I went. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.21% by weight, and the hydrogen selectivity was 20%.

Example 6 In preparing the catalyst, the catalyst was prepared in the same manner as in Example 3 except that a commercially available titanium oxide (manufactured by TAYCA Corporation, anatase type) was used as the carrier instead of the commercially available zirconium oxide. And the reaction was carried out. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.25% by weight, and the hydrogen selectivity was 26%.

Example 7 A catalyst was prepared in the same manner as in Example 3 except that a commercially available zirconium hydroxide (manufactured by Mitsuwa Chemical Co., Ltd.) was used as a carrier in place of the commercially available zirconium oxide in preparing the catalyst. Preparation and reaction were performed. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.50% by weight, and the hydrogen selectivity was 60%.

Example 8 In preparing the catalyst, instead of adding a mixed solution of 50 ml of a dilute solution (1 g-Pd / liter) of a palladium nitrate solution and an aqueous solution containing 2.40 g of commercially available lead nitrate, commercially available bismuth nitrate ( Kanto Chemical Co., Ltd.) 3.46 g
A diluted solution of an aqueous solution in which is dissolved and a palladium nitrate solution (2 g
-Pd / l) A catalyst was prepared in the same manner as in Example 2, except that 50 ml of the mixed solution was added dropwise. The reaction was carried out by the same method as in Example 1 except that 500 mg of the catalyst prepared here was used. 1
After stirring for an hour, the concentration of hydrogen peroxide in the aqueous solution is 0.5
The hydrogen selectivity was 3% by weight and the hydrogen selectivity was 89%.

Example 9 In preparing a catalyst, a commercially available aluminum oxide (Mizusawa Chemical Co., Ltd.) was used as a carrier instead of the commercially available zirconium oxide.
Catalyst preparation and reaction were carried out by the same operations as in Example 8 except that activated alumina) was used. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.35% by weight, and the hydrogen selectivity was 40%.

Example 10 In the preparation of the catalyst, 7.94 g of commercially available gallium nitrate (manufactured by Soegawa Rikagaku Co., Ltd., gallium content 18.9%) was used instead of 2.40 g of commercially available lead nitrate, except that The catalyst was prepared in the same manner as in Example 1. The reaction was carried out by the same method as in Example 1 except that 500 mg of the catalyst prepared here was used. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.79% by weight, and the hydrogen selectivity was 90%.

Example 11 Except that in preparing the catalyst, an aqueous solution containing 1.20 g of commercially available lead nitrate and 3.40 g of commercially available zinc nitrate was used in place of the aqueous solution containing 2.40 g of commercially available lead nitrate.
Catalyst preparation and reaction were carried out in the same manner as in Example 1. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.55% by weight, and the hydrogen selectivity was 85%.

Example 12 In preparing the catalyst, 1.73 g of commercially available bismuth nitrate was used instead of the aqueous solution in which 3.46 g of commercially available bismuth nitrate was dissolved.
Catalyst preparation and reaction were performed in the same manner as in Example 8 except that an aqueous solution in which 3.97 g of commercially available gallium nitrate was dissolved was used. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.70% by weight, and the hydrogen selectivity was 90%.

Comparative Example 1 (Compared to Examples 1, 6, 10 and 11) Example 1 was repeated except that palladium was supported on the titanium oxide support without using commercially available lead nitrate in preparing the catalyst.
Catalyst preparation and reaction were performed by the same operation as above. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.00% by weight, and the hydrogen selectivity was 0%.

Comparative Example 2 (Comparative with Examples 2, 3, 8 and 12) Catalyst preparation and reaction were carried out in the same manner as in Comparative Example 1 except that zirconium oxide was used instead of titanium oxide in the catalyst preparation. It was After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.00% by weight, and the hydrogen selectivity was 0%.

Comparative Example 3 (Compared to Examples 4 and 9) Catalyst preparation and reaction were carried out in the same manner as in Comparative Example 1 except that aluminum oxide was used instead of titanium oxide in the catalyst preparation. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.00% by weight, and the hydrogen selectivity was 0%.

Comparative Example 4 (Comparative to Example 5) Catalyst preparation and reaction were carried out in the same manner as in Comparative Example 1 except that silicon dioxide was used instead of titanium oxide in preparing the catalyst. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the aqueous solution was 0.00% by weight, and the hydrogen selectivity was 0%.

[0026]

According to the present invention, a high concentration of hydrogen peroxide can be produced with a very high hydrogen selectivity. Further, in the present invention, it is not necessary to allow halogen ions to exist in an aqueous solution which is a reaction medium, and various problems caused by the coexistence of a high concentration of halogen ions in a reaction medium as in the conventional method are solved. It

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[Procedure amendment]

[Submission date] July 21, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

Examples of the salt of the platinum group element include salts or complexes of palladium, platinum, ruthenium, osmium, rhodium, iridium or gold, preferably, nitrates, hydrochlorides or acetates of palladium or platinum , or palladium. Alternatively, platinum tetraammine complex is used. The loading amount of the platinum group element is usually 0.1 to 10% by weight with respect to the carrier. Examples of the lead, zinc, gallium or bismuth salt include lead, zinc, gallium or bismuth nitrate, hydrochloride, sulfate or acetate. The amount of lead, zinc, gallium or bismuth in the modified platinum group metal catalyst used in the present invention is at least 1/2 times the weight of the platinum group metal, preferably at least 10 times the weight of the platinum group metal.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michiya Kawakami 6-1-1, Shinjuku, Katsushika-ku, Tokyo Mitsubishi Gas Chemical Co., Ltd. Tokyo Research Laboratory

Claims (6)

[Claims] 1. A method for producing hydrogen peroxide by catalytically reacting oxygen and hydrogen in a reaction medium, wherein lead, zinc,
A method for producing hydrogen peroxide, which comprises using a platinum group metal catalyst modified with at least one element selected from gallium and bismuth. 2. The platinum group metal is palladium.
The method for producing hydrogen peroxide described above. 3. The platinum group metal catalyst is a catalyst in which at least one element selected from lead, zinc, gallium and bismuth and a platinum group metal are both supported on a carrier. 1. The method for producing hydrogen peroxide according to 1. 4. The method for producing hydrogen peroxide according to claim 1, wherein the reaction medium is an acidic aqueous solution. 5. The method for producing hydrogen peroxide according to claim 1, wherein the reaction medium is an aqueous solution containing a stabilizer for hydrogen peroxide. 6. A stabilizer of hydrogen peroxide is aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,
The method for producing hydrogen peroxide according to claim 5, which is at least one selected from the group consisting of 1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), pyrophosphoric acid, and salts thereof.