JPH0543206A - Production of hydrogen peroxide - Google Patents

Abstract

PURPOSE:To produce hydrogen peroxide having high concn. by bringing oxygen and hydrogen into a catalytic reaction with a Pt family metal catalyst deposited on a carrier in a neutral aq. soln. contg. no CONSTITUTION:Oxygen and hydrogen are brought into a catalytic reaction with a Pt family metal catalyst deposited on a solid acid carrier or a solid acid carrier having ultrahigh acidity in a neutral aq. soln. contg. a co-catalyst such as a halogen compd. to produce hydrogen peroxide having high concn.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an improved process for producing hydrogen peroxide by catalytically reacting oxygen and hydrogen with a catalyst in a reaction medium. More specifically, it is a method for producing hydrogen peroxide in which oxygen and hydrogen are catalytically reacted with a platinum group catalyst supported on a solid acid carrier or a solid acid carrier having super strong acidity in a reaction medium containing a cocatalyst. ..

[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. As a problem of this method, reduction,
The processes such as oxidation, water extraction / separation, purification, and concentration are complicated, and the equipment cost and operation cost are high. Further, there are problems such as loss due to deterioration of alkyl anthraquinone and deterioration of hydrogenation catalyst. In order to improve these problems, production methods other than the above production methods have been attempted. One of them is to produce hydrogen peroxide directly from oxygen and hydrogen using a catalyst in a reaction medium. There is a way to do it.
A method for producing hydrogen peroxide from oxygen and hydrogen using a platinum group metal as a catalyst has already been proposed, and it has been shown that a considerable concentration of hydrogen peroxide is produced (Japanese Patent Publication No.
56-47121, Japanese Patent Publication No. 55-18646, Japanese Patent Publication No. 1-23401, and Japanese Patent Publication No. 63-156005). In each of these, an aqueous solution in which an acid or an inorganic salt is dissolved is used as a reaction medium, and in particular, the inclusion of a halogen ion in the reaction medium suppresses the activity of the catalyst and significantly increases the selectivity of hydrogen peroxide generation. Improved and higher concentrations of hydrogen peroxide have been obtained.
For example, in JP-A-63-156005, in a method of producing hydrogen peroxide from oxygen and hydrogen under pressure in an acidic aqueous solution using a platinum group catalyst, halogen ions such as bromine ions are allowed to coexist in the aqueous solution. Discloses that a high concentration of hydrogen peroxide can be selectively produced.

[0003]

In a method for producing hydrogen peroxide by catalytically reacting oxygen and hydrogen with a catalyst in a reaction medium, a high concentration of hydrogen peroxide can be practically obtained by the conventional known techniques. For this purpose, it was necessary to make a high concentration of acid and halogen ions coexist in the reaction medium. In this case, when a high-concentration acidic aqueous solution containing halogen ions is used as the reaction medium, the material of the apparatus that can be used for handling the same is limited, and elution of the catalyst metal into the acidic aqueous solution becomes a problem. The elution of the catalytic metal causes a decrease in catalytic activity and a reduction in catalyst life. Further, the catalytic metal eluted in the acidic aqueous solution deteriorates the quality of the product hydrogen peroxide, and it is extremely difficult to collect the eluted low-concentration metal, which is a serious problem. As described above, the conventional method requires a reactor made of a corrosion-resistant and expensive material, and depending on the use of the obtained hydrogen peroxide, requires post-treatment to remove high-concentration acid or halogen ions. It was also a financial problem because

[0004]

The present inventors have proposed a method of catalytically producing hydrogen peroxide from oxygen and hydrogen by using a neutral reaction medium without addition of acid in a method for catalytically producing hydrogen peroxide. As a result of continuing the study on the production method for obtaining hydrogen oxide, it was found that this object can be achieved by using an oxide having a solid acidity as a carrier of a catalyst having a platinum group element as an active component, and further, among solid acids. In particular, by using a solid acid having a super strong acidity (sometimes referred to as a solid super strong acid) as a carrier, it was found that the effect was more remarkable, and the present invention was completed.

That is, the first object of the present invention is to obtain a high concentration of hydrogen peroxide by catalytically reacting oxygen and hydrogen with a catalyst as a reaction medium in a neutral aqueous solution containing no acid. A method for producing hydrogen peroxide is provided.
The second object of the present invention is to eliminate the step of removing the acid from the obtained hydrogen peroxide because it is not necessary to allow the acid to be present in the reaction medium in the present invention. It is an object of the present invention to provide a method for producing hydrogen peroxide with simplified steps. A third object of the present invention is to provide a novel method for producing hydrogen peroxide, which enables commercial implementation of the method for producing hydrogen peroxide by catalytically reacting oxygen and hydrogen with a catalyst. ..

A solid superacid, which is a kind of solid acid that is a carrier of the catalyst used in the present invention, is a solid exhibiting surface acidity, and its presence depends on the color when an indicator is adsorbed, the adsorption of a base, and the like. It can be confirmed that the acidity is stronger than 100% sulfuric acid (acidity function: H 2 _O
It is a solid acid showing <-11.0 to -11.9). As the solid superacid which is a catalyst carrier used in the present invention, a sulfuric acid-supporting superacid, a metal oxide-supporting superstrong acid or the like can be used.

Specifically, the sulfuric acid-carrying super-strong acid is one in which sulfuric acid is carried on zirconia, titania, alumina, etc., and 0.05-0.5 mol / liter of hydroxide such as zirconium, titanium, aluminum, etc. After adding sulfuric acid so that it spreads over the entire surface and drying,
It can be obtained by firing at a temperature of 800 ° C, preferably 400 to 600 ° C. The metal oxide-supported super strong acid is zirconia-supported molybdenum, zirconia-supported tungsten, etc., and these are 0.1 to 50% by weight, preferably 1 to 30% by weight of molybdenum or molybdenum by the impregnation method, the coprecipitation method or the like. Zirconia added with tungsten is 200 to 1000 ° C., preferably 600 to 800 ° C.
It can be obtained by firing at.

When a solid super strong acid is used as a carrier, the shape thereof may be any of fine powder, granules, pellets and the like. The sulfuric acid-supported super strong acid may cause a problem of elimination of sulfate ion when it is placed in a reducing atmosphere for a long time, and therefore it is preferable to use the metal oxide-supported super strong acid in the reaction. Further, in addition to the super strong acid, a proton type MFI which is a high silica zeolite in which the ratio of silicon to aluminum (Si / Al) in the crystal structure is larger than 3.
-Type zeolite and proton-type mordenite and other solid acids (with an acidity function H _O of -12 <H _O <-3) are used as a carrier, so that hydrogen peroxide can be selectively selected in a reaction medium containing no acid. Can be generated. That is,
The solid acid used as a carrier in the present invention is a solid acid having an acidity function smaller than -3 (H _O <-3), preferably H _O <-11 to -11.9. It is a solid superacid. The shape of the solid acid used as a carrier is not particularly limited, and it may be selected in the form of granules or pellets.

On the other hand, when a carrier which does not exhibit solid acidity such as alumina-magnesia, magnesia and carbon is used as the carrier, the hydrogen selectivity as in the present invention cannot be obtained even under the same conditions.

The catalyst used in the present invention is used by supporting an active ingredient mainly composed of a platinum group element on a carrier made of the above-mentioned solid acid or solid acid exhibiting super strong acidity. As the platinum group element, specifically, palladium or platinum 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, or iridium as the main component. Preferably palladium or platinum is used,
Palladium is particularly preferable. The supported amount of these active metal components on the carrier is 0.1 to 10% by weight. As a method for supporting the platinum group metal on the solid acid carrier or the solid superacid carrier, a known method such as an impregnation method is adopted. When hydrogen peroxide is produced from oxygen and hydrogen, the platinum group catalyst of the present invention is used in an amount of 1 g per liter of reaction medium.
~ 200 g, preferably 5-50 g are used.

As the reaction medium containing a co-catalyst used in the present invention, a neutral aqueous solution containing various known co-catalysts such as halogen compounds (excluding compounds containing only fluorine) or amino acids such as norleucine is used. It As the cocatalyst, a halogen compound is particularly preferable, but as the halogen compound, specifically, a chlorine compound such as sodium chloride, potassium chloride or ammonium chloride,
Bromine compounds such as sodium bromate, sodium bromide, potassium bromide, ammonium bromide and hydrogen bromide, and iodine compounds such as sodium iodide, potassium iodide and ammonium iodide are used, and preferably bromic acid Sodium, sodium bromide, potassium bromide, ammonium bromide or ammonium chloride. In the present invention, hydrogen chloride, hydrogen bromide or the like can be used as a co-catalyst, but in this case, the aqueous solution used as the reaction medium becomes acidic. However, even in such an acidic aqueous solution, the catalyst prepared using the carrier of the present invention gives excellent results. Further, there is no problem in adding a known stabilizer for preventing decomposition of hydrogen peroxide, such as ethylenediaminetetra (methylenephosphonic acid), to the reaction medium.
As the stabilizer of hydrogen peroxide, in addition to the above, aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid or their sodium salts,
Sodium pyrophosphate and the like can be preferably used.

Next, the amount of the cocatalyst used depends on the amount of the catalyst used, but is usually 0.001 per liter of the reaction medium.
It is at least mmol, preferably at least 0.1 mmol.
The upper limit is not particularly limited, but even if added in a large excess, the effect corresponding to the increase in the added amount cannot be obtained. The optimum amount of the co-catalyst is determined in each case depending on the amount of the catalyst and the type of the co-catalyst used.

In the production of hydrogen peroxide of the present invention, oxygen and hydrogen are present in the reaction medium in the presence or absence of an inert gas such as nitrogen which does not interfere with the present reaction, and the reaction pressure is usually 3 to 150 kg. / Cm ² · G, reaction temperature 0 to 50 ° C,
It is carried out by bringing them into contact with each other under a reaction time of 30 minutes to 6 hours.

[0014]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. The analysis value of the gas composition used in the examples is a value obtained by gas chromatography. Further, the concentration of hydrogen peroxide in the reaction solution is measured by sulfuric acid acidity-
It was performed by a titration method using a potassium permanganate solution.

Example 1 A catalyst carrier was prepared by the following method. That is, to a commercially available zirconium hydroxide (manufactured by Mitsuwa Chemical Co., Ltd.), an aqueous solution of commercially available ammonium molybdate (manufactured by Kosou Chemical Co., Ltd.) completely dissolved in pure water was added to change the amount of molybdenum oxide to zirconium oxide. The loading was carried out by the impregnation method so that the ratio was 5% by weight. After drying in a drier at 110 ° C. for a whole day and night, it was calcined in air at 600 ° C. for 3 hours, and a zirconia-molybdenum solid superacid carrier [acidity function (H 2 _{O 2} ) is almost the same as that of zirconia-tungsten. ]
The carrier thus obtained was supported by an impregnation method using an aqueous solution of palladium nitrate so that the amount of palladium as an active ingredient was 1% by weight of the carrier, and the carrier was heated at 400 ° C. for 2 hours in an air stream. After calcination, the catalyst was obtained by reducing at 200 ° C. in a hydrogen stream for 1 hour.

The reaction for producing hydrogen peroxide from oxygen and hydrogen was carried out as follows. A glass container having an internal volume of 65 ml was charged with 10 g of an aqueous solution containing 0.5 mmol / liter of sodium bromate. To this aqueous solution was added 50 mg of the supported palladium catalyst prepared as described above, the glass container was placed in an autoclave having a volume of 100 ml, and then hydrogen gas was 4% by volume, oxygen gas was 40% by volume, and nitrogen gas was 56% by volume. After the air in the autoclave was replaced with the mixed gas having the composition No. 1, the gas having the same composition was pressurized to 50 kg / cm ² · G. The mixture was stirred at 2000 rpm for 1 hour while maintaining the temperature at 10 ° C. After stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.97 wt.
%, And the hydrogen selectivity was 84%. The hydrogen selectivity was calculated by the following formula.

Hydrogen selectivity (%) = [(amount of hydrogen peroxide produced by the reaction mol) / (theoretical amount of hydrogen peroxide produced from the amount of hydrogen consumed)] × 100 The catalyst was filtered off from the solution, and the palladium concentration in the reaction solution was measured by the inductively coupled plasma emission spectrometry (1200VR type analyzer manufactured by Seiko Instruments Inc.). As a result, it was 0.0 ppm.

Example 2 To a commercially available zirconium hydroxide (manufactured by Mitsuwa Chemical Co., Ltd.), an aqueous solution of commercially available ammonium tungstate (manufactured by Kosou Chemical Co., Ltd.) completely dissolved in pure water was added to obtain the amount of tungsten oxide. Of the zirconia-tungsten solid superacid (H) which was carried by the impregnation method so that the ratio was 5% by weight with respect to zirconium oxide, dried in a dryer at 110 ° C. for one day and then calcined in air at 600 ° C. for 3 hours. _O ≤ -14.5
Catalyst preparation and hydrogen peroxide production reaction were carried out in the same manner as in Example 1 except that 2) was used as the catalyst carrier. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 1.06 wt% and the hydrogen selectivity was 99%. Further, the catalyst was filtered off from the solution after the reaction, and the palladium concentration in the reaction solution was measured by inductively coupled plasma emission spectrometry (using a 1200 VR type analyzer manufactured by Seiko Instruments Inc.).
It was 0.1 ppm as a result of measurement.

Comparative Example 1 Commercially available silicon dioxide (manufactured by Mizusawa Chemical Co., Ltd.) was used as a catalyst carrier, and sodium bromate (0.5 mmol / mol) was used as a reaction medium.
Example 1 except that 10 g of an aqueous solution containing 0.1 mol / liter of sulfuric acid and 0.5 mmol / liter of sodium bromate was used instead of 10 g of an aqueous solution containing liter.
The same operation as above was carried out to carry out a catalyst preparation and a hydrogen peroxide production reaction. After stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.97 wt% and the hydrogen selectivity was 90%.
Met. Further, the catalyst was filtered off from the solution after the reaction, and the palladium concentration in the reaction solution was measured by an inductively coupled plasma emission spectrometry (1200VR type analyzer manufactured by Seiko Instruments Inc.). It was Compared with the results of Examples 1 and 2, it can be seen that the amount of palladium eluted is considerably large when sulfuric acid is used as in the known method.

Example 3 A catalyst was prepared in the same manner as in Example 1 except that the zirconia-molybdenum solid superacid used in Example 1 was calcined in air at 800 ° C. for 3 hours and used as a catalyst carrier. Preparation and hydrogen peroxide production reaction were performed. After stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.78 wt.
%, And the hydrogen selectivity was 80%.

Example 4 A catalyst was prepared in the same manner as in Example 1 except that the zirconia-tungsten solid superacid used in Example 2 was calcined in air at 800 ° C. for 3 hours and used as a catalyst carrier. Preparation and hydrogen peroxide production reaction were performed. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.77w
t%, and the hydrogen selectivity was 72%.

Example 5 A catalyst carrier was prepared by the following method. That is, with respect to 2 g of commercially available zirconium hydroxide (manufactured by Mitsuwa Chemical Co., Ltd.) on filter paper, 30 m of sulfuric acid of 0.5 mol / liter
1, poured in air, dried in a dryer at 110 ° C. for 24 hours, and then calcined in air at 600 ° C. for 3 hours to give a zirconia-supported sulfuric acid solid superacid carrier (H 2 _O ≦ −16.
04) was obtained. Except that the carrier obtained here was used, the same procedure as in Example 1 was carried out to carry out the catalyst preparation and hydrogen peroxide production reaction. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.25 wt% and the hydrogen selectivity was 67%.

Example 6 Similar to Example 2 except that 10 g of an aqueous solution containing 0.2 mol / liter of ammonium chloride was used as the reaction solution instead of 10 g of an aqueous solution containing 0.5 mmol / liter of sodium bromate. Then, the catalyst preparation and hydrogen peroxide production reaction were performed. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.70 wt% and the hydrogen selectivity was 61%.

EXAMPLE 7 The zirconia-molybdenum solid superacid carrier used in Example 1 was impregnated with an aqueous solution of hexachloroplatinic acid to obtain an amount of platinum as an active ingredient of 0.5% by weight based on the carrier.
Using a catalyst supported so as to have a ratio of 10 mM, 10 g of an aqueous solution containing 0.5 mmol / liter of potassium iodide was used as the reaction solution instead of 10 g of an aqueous solution containing 0.5 mmol / liter of sodium bromate. Except for the above, the same operation as in Example 1 was carried out to carry out a catalyst preparation and a hydrogen peroxide production reaction. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.58 wt% and the hydrogen selectivity was 48%.

Example 8 Proton-type mordenite (Si / Al = 1) was used as a catalyst carrier.
8, the same operation as in Example 1 was carried out except that H 2 _O <-5.6) was used to carry out a catalyst preparation and a hydrogen peroxide production reaction. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.64 wt% and the hydrogen selectivity was 38%.

Example 9 Proton-type MFI-type zeolite (S
The same operations as in Example 1 were carried out except that i / Al = 15 and H 2 _O <−5.6) were used to carry out a catalyst preparation and a hydrogen peroxide production reaction. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.49 wt% and the hydrogen selectivity was 46%.

Comparative Example 2 The following operation was carried out using an impregnation method as a method for preparing the catalyst carrier. That is, commercially available aluminum oxide (manufactured by Kanto Chemical Co., Inc.)
In contrast, separately sold magnesium nitrate (manufactured by Kanto Chemical Co., Inc.)
Was completely dissolved, and the mixture was added so that the weight ratio of alumina to magnesia was 85:15, and the mixture was stirred and mixed for 2 hours, evaporated to dryness on a hot plate, and further dried at 110 ° C in a dryer. After drying overnight, 5 in air flow
The carrier was obtained by baking at 00 ° C. for 2 hours. Except that the carrier obtained here was used, the same operations as in Example 1 were carried out to carry out the catalyst preparation and hydrogen peroxide production reaction. After stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.01 wt%
And the hydrogen selectivity was 2%.

Comparative Example 3 Catalyst preparation and hydrogen peroxide production reaction were performed in the same manner as in Example 1 except that commercially available magnesium oxide (manufactured by Kanto Chemical Co., Inc.) was used as the catalyst carrier. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.00 wt% and the hydrogen selectivity was 0%.

Comparative Example 4 Carbon powder supporting 5% by weight of palladium as a catalyst (manufactured by NE Chemcat: water content = 52.24%)
The same operation as in Example 1 was performed except that 21 mg of the product) was added to carry out a hydrogen peroxide production reaction. After stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.02 wt%
And the hydrogen selectivity was 1%.

Comparative Example 5 Proton type A-type zeolite (Si / Al =
Catalyst preparation and hydrogen peroxide production reaction were carried out in the same manner as in Example 1 except that 1, -3.0 <H 2 _O <+3.3) was used. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.15 wt% and the hydrogen selectivity was 18%.

Comparative Example 6 Sodium mordenite (Si / Al =
18, the same operation as in Example 1 was carried out except that -3.0 <H 2 _O <+3.3) was used to carry out catalyst preparation and hydrogen peroxide production reaction. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.08 wt% and the hydrogen selectivity was 5%.

Comparative Example 7 The same operation as in Example 1 was carried out except that sodium type MFI type zeolite (Si / Al = 15, −3.0 <H 2 _O <+3.3) was used as the catalyst carrier. Catalyst preparation and hydrogen peroxide production reaction were performed. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.10 wt% and the hydrogen selectivity was 8%.

Example 10 Instead of 10 g of an aqueous solution containing 0.5 mmol / liter of sodium bromate as a reaction solution, 75 ppm of ethylenediaminetetra (methylenephosphonic acid) and 0.5 ppm were added.
Aqueous solution containing 1 mmol / l sodium bromate
The same operations as in Example 2 were carried out except that 0 g was used to prepare a catalyst and carry out a hydrogen peroxide production reaction. After stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 1.04.
wt%, and the hydrogen selectivity was 90%.

Example 11 As a reaction solution, 10 g of an aqueous solution containing 60 ppm of sodium pyrophosphate and 0.5 mmol / liter of sodium bromate was used instead of 10 g of an aqueous solution containing 0.5 mmol / liter of sodium bromate. Except
The same operations as in Example 1 were carried out to prepare a catalyst and carry out a hydrogen peroxide production reaction. After completion of stirring for 1 hour, the hydrogen peroxide concentration in the reaction solution was 0.98 wt% and the hydrogen selectivity was 87%.

Example 12 As Example 2, except that 10 g of an aqueous solution containing 0.1 mmol / liter of sodium bromide was used in place of 10 g of an aqueous solution containing 0.5 mmol / liter of sodium bromate as a reaction solution. The same operation was performed to carry out a catalyst preparation and a hydrogen peroxide production reaction. After stirring for 1 hour,
The hydrogen peroxide concentration in the reaction solution was 0.78 wt%,
The hydrogen selectivity was 89%.

Comparative Example 8 The same operation as in Example 1 except that 10 g of an aqueous solution containing 50 mmol / liter of ammonium fluoride was used as the reaction solution instead of 10 g of an aqueous solution containing 0.5 mmol / liter of sodium bromate. Then, catalyst preparation and hydrogen peroxide production reaction were carried out. After stirring for 1 hour,
The hydrogen peroxide concentration in the reaction solution is 0.00 wt%,
The hydrogen selectivity was 0%.

[0037]

EFFECTS OF THE INVENTION In the examples of the present invention as compared with the comparative examples, the obtained concentration of hydrogen peroxide and the hydrogen selectivity are very high. By using the platinum group catalyst of the present invention, it is possible to obtain Highly concentrated hydrogen peroxide can be selectively produced without the presence of acid. As described above, in the present invention, since it is not necessary to allow a high concentration of acid to coexist in the reaction medium, it is possible to reduce problems such as the material of the reactor and elution of the catalyst into the reaction medium unlike the conventional method.

Claims (12)

[Claims] 1. A method for producing hydrogen peroxide by catalytically reacting oxygen and hydrogen with a platinum group catalyst in a reaction medium, comprising a solid acid carrier or super-strong acidity in a reaction medium containing a cocatalyst. A method for producing hydrogen peroxide, which comprises using a platinum group catalyst supported on a solid acid carrier. 2. The method for producing hydrogen peroxide according to claim 1, wherein the platinum group catalyst is palladium or platinum. 3. The method for producing hydrogen peroxide according to claim 1, wherein the solid acid carrier having super strong acidity is a sulfuric acid-supporting super strong acid carrier or a metal oxide-supporting super strong acid carrier. 4. The method for producing hydrogen peroxide according to claim 3, wherein the sulfuric acid-carrying superacid carrier according to claim 3 is one in which sulfuric acid is carried on zirconia, alumina, and titania. 5. The method for producing hydrogen peroxide according to claim 3, wherein the metal oxide-supported super strong acid carrier according to claim 3 is zirconia-supported molybdenum or zirconia-supported tungsten. 6. The method for producing hydrogen peroxide according to claim 1, wherein the solid acid carrier is a proton type mordenite or a proton type MFI type zeolite. 7. The method for producing hydrogen peroxide according to claim 1, wherein the co-catalyst is a halogen compound (excluding compounds containing only fluorine). 8. The method for producing hydrogen peroxide according to claim 7, wherein the halogen compound according to claim 7 is sodium bromate, sodium bromide, potassium bromide, ammonium bromide or ammonium chloride. 9. The method for producing hydrogen peroxide according to claim 1, wherein the reaction medium is an aqueous solution containing a cocatalyst. 10. The method for producing hydrogen peroxide according to claim 1, wherein the reaction medium is an aqueous solution containing a cocatalyst and a stabilizer for hydrogen peroxide. 11. The stabilizer of claim 10 is aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,
The method for producing hydrogen peroxide according to claim 10, which is one or more compounds selected from the group consisting of 1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid) or their sodium salts, and sodium pyrophosphate. 12. Oxygen and hydrogen in the presence or absence of an inert gas in a reaction medium in the presence of a catalyst at a reaction temperature of 0 ° C.
-50 ° C, reaction pressure 3 kg / cm ² · G-150 kg /
The method for producing hydrogen peroxide according to claim 1, wherein the reaction is performed at cm ² · G.