JP2000229239A - Supported ruthenium oxide catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the activity of a supported ruthenium oxide catalyst and to produce chlorine by the oxidation of hydrogen chloride with oxygen in the presence of a smaller amount of the catalyst at a lower reaction temperature by supporting a ruthenium oxide catalyst on a titanium dioxide support containing not less than a specified proportion of titanium dioxide having a rutile crystal system. SOLUTION: A ruthenium oxide catalyst supported on titanium dioxide having a rutile crystal system has higher activity than a ruthenium oxide catalyst supported on titanium dioxide having an anatase crystal system or amorphous titanium dioxide and the catalytic activity increases in accordance with the increase of the proportion of rutile crystals in titanium dioxide. It is necessary that titanium dioxide used contains >=20% rutile crystals and the preferred proportion of rutile crystals is >=30% or >=80% or >=90%. In respect of catalytic activity, an appropriate OH group content range is present according to the amount of the supported ruthenium compound and the resulting catalyst exhibits high activity in the range. The OH group content is usually 0.1×10-4-30×10-4 mol/per 1 g support.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a supported ruthenium oxide catalyst. More particularly, the present invention relates to a supported ruthenium oxide catalyst for producing chlorine by oxidizing hydrogen chloride with oxygen, which has a high activity and is characterized by being able to produce the target compound at a lower reaction temperature with a smaller amount of catalyst.

[0002]

2. Description of the Related Art It is known that a supported ruthenium oxide catalyst is useful as a catalyst in a method for producing chlorine by an oxidation reaction of hydrogen chloride, and is obtained by hydrolyzing, oxidizing and calcining ruthenium chloride. For example, Japanese Patent Laid-Open No. 9-67103
The publication describes that a ruthenium compound supported on titanium oxide can be obtained by hydrolyzing a ruthenium compound with an alkali metal hydroxide, and then supporting the compound on titanium hydroxide and calcining with air. We have also found that a supported ruthenium oxide catalyst can be obtained by oxidizing a supported metal ruthenium catalyst. As the supported metal ruthenium catalyst, for example, after supporting and drying ruthenium chloride on a carrier, a method of preparing a supported metal ruthenium catalyst by heating in a hydrogen stream or drying after supporting the ruthenium chloride on a carrier, A method of preparing a supported metal ruthenium catalyst by reduction with sodium borohydride may be mentioned. However, when ruthenium chloride is reduced with hydrogen, ruthenium sintering occurs, and there is a problem that a supported ruthenium oxide catalyst prepared by oxidizing a hydrogen reduction catalyst has low activity.

Conventionally, a supported ruthenium oxide catalyst using an anatase crystal system or amorphous titanium oxide as a carrier has been highly active in oxidizing hydrogen chloride. However, development of a catalyst having higher activity has been desired. .

[0004] Industrially, both high activity of the catalyst and high activity per unit weight of ruthenium contained in the catalyst are required. Since the activity per unit weight of ruthenium contained in the catalyst is high, the amount of ruthenium contained in the catalyst can be reduced, which is advantageous in cost. Generally, by using a highly active catalyst and conducting the reaction at a lower temperature, more favorable reaction conditions can be selected in an equilibrium manner. In addition, it is preferable to carry out the reaction at a lower temperature in terms of catalyst stability.

[0005] When the activity of the catalyst is low, a higher reaction temperature is required, but the reaction of oxidizing hydrogen chloride with oxygen to produce chlorine is an equilibrium reaction. And the equilibrium conversion of hydrogen chloride decreases. Therefore, if the catalyst has high activity, the reaction temperature can be lowered, so that the reaction becomes equilibrium advantageous and a higher conversion of hydrogen chloride can be obtained. In addition, when the reaction temperature is high, there is a possibility that the activity may be reduced due to the volatilization of the catalyst component. In view of this, the development of a catalyst having high activity and usable at a low temperature has been desired.

Conventionally, the surface OH of titanium oxide as a carrier is
When the group content was too large or too small, the catalyst with the optimum activity could not be obtained, and in some cases, the catalyst activity decreased.

[0007]

Under these circumstances, an object of the present invention is to provide a supported ruthenium oxide catalyst for oxidizing hydrogen chloride to produce chlorine, which has a higher activity and a smaller amount of catalyst. And to provide a catalyst capable of producing the target compound at a lower reaction temperature.

[0008]

That is, the present invention relates to a supported ruthenium oxide catalyst for producing chlorine by oxidizing hydrogen chloride with oxygen, comprising a titanium oxide carrier containing at least 20% of rutile crystalline titanium oxide. The present invention relates to a supported ruthenium oxide catalyst supported on.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The supported ruthenium oxide catalyst of the present invention is a supported ruthenium oxide catalyst using a titanium oxide containing 20% or more of rutile crystalline titanium oxide as a carrier. Crystal systems, anatase crystal systems, amorphous and the like are known. The titanium oxide containing 20% or more of the rutile crystal-based titanium oxide of the present invention refers to a titanium oxide that contains rutile crystals in which the ratio of rutile crystals to anatase crystals in titanium oxide is measured by X-ray diffraction analysis. . The measuring method will be described later in detail. When the chemical composition of the carrier of the present invention is titanium oxide alone, the ratio of rutile crystals is determined from the ratio of rutile crystals and anatase crystals in titanium oxide by X-ray diffraction analysis. In this case, the ratio of rutile crystals is determined by the following method. Examples of the oxide that is complexed with titanium oxide include elemental oxides, and preferably include alumina, zirconium oxide, and silica. The ratio of rutile crystals in the composite oxide is determined from the ratio of rutile crystals and anatase crystals in titanium oxide by X-ray diffraction analysis, but it is necessary to include at least 20% of rutile crystals. It is. At this time, the content of the oxide other than titanium oxide in the composite oxide is in the range of 60% by weight or less. Preferred carriers include titanium oxide containing no metal oxide other than titanium oxide.

The ruthenium oxide catalyst supported on rutile crystal titanium oxide has a higher activity than the ruthenium oxide catalyst supported on anatase crystal or amorphous titanium oxide, and the ratio of rutile crystal in titanium oxide is high. The higher the is, the greater the catalytic activity. Therefore, it is necessary that the titanium oxide contains rutile crystals in an amount of 20% or more. Preferably, the rutile crystal ratio is 30% or more, more preferably 80% or more, and most preferably 90% or more. That is all.

There are various methods for preparing titanium oxide containing rutile crystals, and the following preparation examples are generally given. For example, when titanium tetrachloride is used as a raw material, titanium tetrachloride is dropped and dissolved in ice-cooled water and neutralized with an aqueous ammonia solution to generate titanium hydroxide (ortho titanic acid). Thereafter, the generated precipitate is washed with water to remove chlorine ions. At this time, when the temperature at the time of neutralization becomes a high temperature of 20 ° C. or more, or when chlorine ions remain in the titanium oxide after washing, a stable transition to rutile crystal system at the time of firing occurs. More likely to happen. The firing temperature is 600 ° C
Above this, rutile occurs (catalyst preparation chemistry, 198).
9 years, 211 pages, Kodansha). In addition, for example, a reaction gas is prepared by passing an oxygen-nitrogen mixed gas into a titanium tetrachloride evaporator and introduced into the reactor. The reaction between titanium tetrachloride and oxygen starts at around 400 ° C., and titanium dioxide produced by the reaction of the TiCl ₄ —O ₂ system is mainly of anatase type, but when the reaction temperature exceeds 900 ° C., the formation of rutile type occurs. (Catalyst preparation chemistry, 1989, page 89, Kodansha). Further, for example, a method in which titanium tetrachloride is hydrolyzed in the presence of ammonium sulfate and then calcined (for example, Catalyst Engineering Course 10 Handbook of Catalysts by Element, 1978, 254)
Page, Jinjinshokan), a method of calcining anatase crystalline titanium oxide (for example, metal oxide and composite oxide, 1980)
Year, page 107, Kodansha). Further, a method of heating and hydrolyzing an aqueous solution of titanium chloride, or a method of previously mixing an aqueous solution of a titanium compound such as titanium sulfate or titanium chloride and titanium oxide powder of rutile crystal, and then subjecting the mixture to thermal hydrolysis or alkaline hydrolysis, By firing at a low temperature of about ℃, rutile crystal titanium oxide is also generated.

The method of determining the ratio of rutile crystals in titanium oxide is X-ray diffraction analysis, and various X-ray sources are used. For example, Kα radiation of copper and the like can be mentioned. When copper Kα radiation was used, the ratio of the rutile crystal and the ratio of the anatase crystal were respectively the intensity of the diffraction peak at 2θ = 27.5 degrees on the (110) plane and the intensity of the diffraction peak at (101).
It is determined using the intensity of the diffraction peak at 2θ = 25.3 degrees of the plane. The carrier used in the present invention has a peak intensity of rutile crystal and a peak intensity of anatase crystal.
Alternatively, it has a peak intensity of rutile crystal. That is, it has both the diffraction peak of the rutile crystal and the diffraction peak of the anatase crystal, or has only the diffraction peak of the rutile crystal. The ratio of the peak intensity of the rutile crystal to the sum of the peak intensity of the rutile crystal and the peak intensity of the anatase crystal is 20% or more, and preferably 30% or more.

Further, rutile crystal titanium oxide is used in an amount of 20%.
In a supported ruthenium oxide catalyst using the titanium oxide carrier contained above, the catalytic activity can be improved by optimizing the amount of OH groups contained in the carrier.
Generally, it is known that a hydroxyl group represented by OH bonded to Ti exists on the surface of titanium oxide. The titanium oxide used in the present invention contains an OH group, and a method for measuring the content will be described later in detail. When the chemical composition of the carrier used in the present invention is titanium oxide alone, it is determined from the OH group content in the titanium oxide. In the present invention, a composite oxide of titanium oxide and another metal oxide is also included. Examples of the oxide that is complexed with titanium oxide include elemental oxides, and preferably include alumina, zirconium oxide, and silica. At this time, the content of the oxide other than titanium oxide in the composite oxide is in the range of 0 to 60 wt%. Also in this case, the OH group content per unit weight of the carrier contained in the carrier is determined by a measurement method which will be described later in detail. Preferred carriers include titanium oxide containing no metal oxide other than titanium oxide.

When the OH group content of the carrier is large,
Ruthenium oxide may react and inactivate.
On the other hand, when the OH group content of the carrier is small,
Sintering and other phenomena of the catalyst
Performance may be reduced. That is, the catalytic activity is supported.
Depending on the amount of the ruthenium compound, an appropriate OH group content
There is a region, within which the catalytic activity increases with increasing OH groups
Gradually increased, peaked, and then declined.
You. Therefore, the catalyst has high activity within the appropriate OH group content.
Shows sex. The amount of OH groups in the titanium oxide carrier
0.1 × 10 ^-Four~ 30 × 10^-Four(Mol / g-carrier)
And preferably 0.2 × 10^-Four~ 20 × 10^-Four(M
ol / g-carrier), more preferably 3.0 × 10^-Four~ 1
0x10 ^-Four(Mol / g-carrier).

There are various methods for determining the OH group content of titanium oxide. For example, there is a method using a thermogravimetric method (TG). When the thermogravimetric method is used, the temperature is kept constant, excess water in the sample is removed, then the temperature is raised, and the OH group content is measured from the weight loss. In this method, the amount of the sample is small and accurate measurement is difficult. Further, when a thermally decomposable impurity is present in the carrier, there is a disadvantage that the actual OH group content cannot be determined accurately. Similarly, in the case of using the ignition loss measurement (Igloss) for measuring the OH group content from the weight loss of the sample, a high-precision measurement can be performed by increasing the amount of the sample. Affected by pyrolytic impurities. Furthermore, the weight loss obtained by the thermogravimetric method or the measurement of loss on ignition has a drawback that it includes up to the bulk OH group content which is not effective during catalyst preparation.

Further, there is a method using sodium naphthalene. In this method, an OH group in a sample is reacted with sodium naphthalene as a reagent, and the OH group content is measured from an appropriate amount of sodium naphthalene. In this case, a change in the concentration of the appropriate reagent or a small amount of water greatly affects the result, and the measurement result is affected by the storage state of the reagent, so that it is extremely difficult to obtain an accurate value.

Further, a suitable method using an alkyl alkali metal can be used. As an appropriate method using an alkyl alkali metal, a titanium oxide carrier or a titanium oxide carrier powder is suspended in a dehydrated solvent, and the alkyl alkali metal is dropped in a nitrogen atmosphere. A preferred method is a method for determining the amount of OH groups contained in the polymer. At that time, the water contained in the dehydrated solvent and the alkyl alkali metal react with each other to generate hydrocarbons. Therefore, the amount must be subtracted from the measured value to determine the OH group content in the titanium oxide.

The most preferable method is that a titanium oxide carrier or a titanium oxide carrier powder is suspended in dehydrated toluene, methyllithium is dropped in a nitrogen atmosphere, and the amount of methane generated is contained in the titanium oxide. There is a method for determining the OH group content, and the OH group content in the titanium oxide carrier defined in the claims of the present invention is a value determined by this method.

As a measuring procedure, for example, the following method can be mentioned. First, the sample was previously placed in air at 150 ° C.
After drying for 2 hours, the mixture is cooled in a desiccator. Thereafter, a predetermined amount of the sample is transferred into a flask purged with nitrogen,
Suspend in an organic solvent such as dehydrated toluene. The flask is cooled with ice to suppress heat generation, methyl lithium is dropped from the dropping funnel, the generated gas is collected, and the volume at the measured temperature is measured.

There are various methods for adjusting the content of the OH group contained in the titanium oxide carrier to a predetermined amount. For example, the firing temperature and firing time of the carrier can be mentioned. The OH groups in the titanium oxide carrier are eliminated by applying heat, but the OH group content can be controlled by changing the firing temperature and the firing time. The firing temperature of the carrier is usually 100 to 1000 ° C, preferably 150 to 800 ° C.
Is raised. The sintering time of the carrier is usually 30 minutes to 1
2 hours. In this case, it should be noted that the surface area of the support decreases as the firing temperature increases and the firing time increases. In addition, when the titanium oxide is produced in a gas phase, one having a small OH group content can be produced, and when the titanium oxide is produced from an aqueous phase such as an aqueous solution, one having a large OH group content can be produced. Further, there are a method of treating the OH group of the carrier with an alkali, and a method of reacting the OH group with an OH group using 1,1,1-3,3,3-hexamethyldisilazane or the like.

The present invention relates to a supported ruthenium oxide catalyst supported on the above-mentioned carrier, and the weight ratio of ruthenium oxide to the carrier is usually 0.1 / 99.9 to 20.0 / 80.0, preferably Is 0.5 / 99.5 to 15.0 / 85.
0, more preferably 1.0 / 99.0 to 15.0.
/85.0. If the ratio of ruthenium oxide is too low, the activity may decrease, and if the ratio of ruthenium oxide is too high, the price of the catalyst may increase. Examples of the ruthenium oxide to be supported include ruthenium dioxide, ruthenium hydroxide, and the like.

There are various methods for preparing a supported ruthenium oxide catalyst using the above-mentioned carrier.

A first example of the method for preparing a supported ruthenium oxide catalyst according to the present invention is a method in which a ruthenium compound supported on a carrier is reduced with a reducing hydrogenation compound and then oxidized to prepare the same.

As a ruthenium compound supported on a carrier
Is RuCl_Three, RuCl_ThreeRuthenium chloride such as hydrate
Thing, K_ThreeRuCl₆, [RuCl₆]^3-, K_TwoRuCl₆What
Which chlororuthenate, [RuCl_Five(H_TwoO)_Four]
^2-, [RuCl_Two(H_TwoO)_Four]⁺Such as chlororuthenium
Acid salt hydrate, K_TwoRuO_FourRuthenic acid salts such as Ru
_TwoOCI_Four, Ru_TwoOCI_Five, Ru_TwoOCI₆Such as Ruteniu
Moxy chloride, K_TwoRu_TwoOCI_Ten, Cs_TwoRu_TwoOCI
_FourRuthenium oxychloride salts such as [Ru (NH_Three)
₆]²⁺, [Ru (NH_Three)₆]³⁺, [Ru (NH_Three)_FiveH
_TwoO]²⁺Ruthenium ammine complex such as [Ru (N
H_Three)_FiveCl]²⁺, [Ru (NH_Three)₆] Cl_Two, [Ru
(NH_Three)₆] Cl_Three, [Ru (NH_Three)₆] Br_ThreeSuch as le
Chloride, bromide, RuBr of ruthenium ammine complex_Three,
RuBr_ThreeRuthenium bromide such as hydrates, other ruthenium
Ruthenium organic amine complex, ruthenium acetylacetona
Complex, Ru (CO)_Five, Ru_Three(CO)₁₂Such as lute
Carbonyl complex, [Ru_ThreeO (OCOCH_Three)
₆(H_TwoO)_ThreeOCOCH_ThreeHydrate, Ru_Two(RCOO)
_FourRuthene such as Cl (R = alkyl group having 1-3 carbon atoms)
Organic salt, K_Two[RuCl_FiveNO)], [Ru (NH
_Three)_Five(NO)] Cl_Three, [Ru (OH) (NH_Three)_Four(N
O)] (NO_Three)_Two, Ru (NO) (NO_Three)_ThreeSuch as le
Ruthenium nitrosyl complex, ruthenium phosphine complex
Which compounds are mentioned. Preferred ruthenium compounds
As a material, RuCl_Three, RuCl_ThreeLute such as hydrate
Chloride, RuBr_Three, RuBr_ThreeHydrates
Ruthenium compounds such as ruthenium bromide
Can be More preferably, ruthenium chloride hydrate is used.
Can be

Examples of the reducing hydrogenated compound for reducing a ruthenium compound supported on a carrier include NaBH ₄ , Na ₂ B _{2
H 6, Na 2 B 4 H} 10, Na 2 B 5 H 9, LiBH 4, K 2 B 2
_{H 6, K 3 B 4 H} 10, K 2 B 5 H 9, Al (BH 4) 3 borohydride compound such as, LiB _{[CH (CH 3) C 2 H} 5 ]
_{3 H, LiB (C 2 H} 5) 3 H, KB [CH (CH ₃₎ C ₂ H
₅ ] ₃ H, organometallic borohydride compounds such as KB [CH (CH ₃ ) CH (CH ₃ ) ₂ ] ₃ H, LiAlH, Na
Metal hydrides such as H, LiH and KH, [(CH ₃ ) ₂ C
HCH ₂ ] ₂ AlH and other organometallic hydrides. Preferred reducing agents include NaBH ₄ , Na ₂ B
_{2 H 6, Na 2 B 4} H 10, Na 2 B 5 H 9, LiBH 4, K 2 B
_{2 H 6, K 3 B 4} H 10, K 2 B 5 alkali metal borohydride compound such as H ₉ and the like. More preferably, NaBH
₄ are given.

As a specific example of preparing the supported ruthenium oxide catalyst of the present invention, a preparation method including the following steps can be mentioned. Ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier Reduction step: a step of reducing the one obtained in the ruthenium compound supporting step with a reductive hydride compound An oxidizing step: a step of oxidizing the one obtained in the reducing step

As a preferred specific example of preparing the supported ruthenium oxide catalyst of the present invention, a preparation method including the following steps can be mentioned. Ruthenium halide supporting step: a step of supporting ruthenium halide on a catalyst support Reduction step: a step of reducing the product obtained in the ruthenium halide supporting step with sodium borohydride

Further, as a more preferred specific example of preparing the supported ruthenium oxide catalyst of the present invention, a preparation method including the following steps can be mentioned. Ruthenium halide supporting step: Step of supporting ruthenium halide on the catalyst support Reduction step: Step of reducing the one obtained in the ruthenium halide impregnating step with sodium borohydride Alkali metal chloride adding step: One obtained in the reducing step Step of adding alkali metal chloride to the water Oxidation step: oxidation of the substance obtained in the alkali metal chloride impregnation step

The ruthenium halide supporting step is a step of supporting ruthenium halide on a catalyst carrier. Preferred ruthenium halide compounds include RuC
l ₃ , ruthenium chlorides such as RuCl ₃ hydrate, Ru
Ruthenium halide compounds such as ruthenium bromide such as Br ₃ and RuBr ₃ hydrate can be mentioned. More preferably, hydrated ruthenium chloride is used. Examples of the method for supporting ruthenium halide include an impregnation method and an equilibrium adsorption method. The impregnation method is a preferred method.

The amount of ruthenium halide used in the ruthenium halide supporting step is usually an amount corresponding to a preferable weight ratio of ruthenium oxide to the carrier. That is, the catalyst carrier exemplified above is impregnated with a solution of ruthenium halide. As the solvent, an organic solvent such as water or alcohol is used, and preferably, water is used. A ruthenium compound other than ruthenium halide can be used. However, when a compound that does not dissolve in water is used, a soluble organic solvent such as hexane or tetrahydrofuran is used as the solvent. Next, the impregnated material can be dried or reduced without drying, but a method of drying is a preferred example. The condition for drying the impregnated material is preferably 50 to 200 ° C., and preferably 1 to 10 hours.

In the reduction step, the product obtained in the ruthenium halide supporting step is subjected to sodium borohydride (NaBH ₄ ).
This is the step of reducing. As a method of the reduction step, there is a method of immersing the product obtained in the ruthenium halide supporting step in a solution of sodium borohydride. Examples of the sodium borohydride solution include an aqueous solution and a solution of an organic solvent such as alcohol, and a mixed solution of water and an organic solvent can also be used. Preferably, a mixed solvent of water and alcohol is used, and more preferably, a mixed solvent of water and ethanol is used. The concentration of the sodium borohydride solution is usually from 0.05 to 20% by weight, preferably from 0.1 to 10% by weight. The molar ratio of sodium borohydride to the supported ruthenium halide is usually from 1.0 to 30, preferably from 2.0 to 15. After the catalyst is reduced,
The washing may be performed with water, or the operation of a step of washing with an aqueous solution of an alkali metal chloride, which is the operation of the next alkali metal chloride adding step, may be performed. Preferably, a method of washing with water after reduction and drying is used.

The reduction can be carried out with a reducing hydride compound other than sodium borohydride. In this case, an aprotic anhydrous solvent is preferably used. For example, reduction of a ruthenium compound supported by a reducing hydride compound other than sodium borohydride using a toluene solvent may be mentioned as an example.

The alkali metal chloride addition step is a step of adding an alkali metal chloride to the product obtained in the reduction step. Although this step is not an essential step for preparing a supported ruthenium oxide catalyst, the activity of the catalyst is further improved by performing this step. That is, the catalyst is oxidized in the next oxidation step, in which case, in the presence of an alkali metal salt,
It is a preferred preparation example to convert the supported metal ruthenium to highly active supported ruthenium oxide by oxidation.

As the alkali metal salt, potassium chloride,
Alkali metal chlorides such as sodium chloride can be mentioned, preferably potassium chloride, sodium chloride,
More preferably, it is potassium chloride.

Here, the molar ratio of alkali metal salt / ruthenium is preferably from 0.01 to 10, more preferably from 0.1 to 5. If the amount of the alkali metal salt is too small, a sufficiently high activity catalyst cannot be obtained.

As a method of adding the alkali metal chloride aqueous solution, a method of impregnating a washed and dried supported metal ruthenium catalyst can be mentioned. A method of impregnating by washing with an aqueous metal chloride solution is also included.

After the addition of the alkali metal chloride, the catalyst is usually dried.

The oxidation step is a step of oxidizing the product obtained in the reduction step (when the alkali metal chloride addition step is not used).
Or a step of oxidizing the product obtained in the alkali metal chloride addition step (when the alkali metal chloride addition step is used). As the oxidation step, a method of firing in air can be mentioned. It is a preferable preparation example that the supported metal ruthenium is oxidized to highly active supported ruthenium oxide by calcining the supported metal ruthenium in the presence of an alkali metal salt in a gas containing oxygen. Air is usually used as the gas containing oxygen.

The firing temperature is usually 100 to 600 ° C., preferably 280 to 450 ° C. If the firing temperature is too low, a large amount of metal ruthenium particles may remain, and the catalytic activity may be insufficient. On the other hand, if the firing temperature is too high, agglomeration of the ruthenium oxide particles occurs, and the catalytic activity decreases. The firing time is usually 30 minutes to 10 hours.

In this case, the calcination is preferably performed in the presence of an alkali metal salt. By this method, finer particles of ruthenium oxide are produced, and higher catalytic activity can be obtained as compared with calcining in the substantial absence of an alkali metal salt.

By the calcination, the metal ruthenium supported on the carrier is converted into a supported ruthenium oxide catalyst. The conversion of metal ruthenium to ruthenium oxide can be confirmed by analysis such as X-ray diffraction or XPS (X-ray photoelectron spectroscopy). It is preferable that substantially all of the metal ruthenium is converted into ruthenium oxide, but it is acceptable that the metal ruthenium remains as long as the effect of the present invention is not impaired.

A preferred method is to oxidize the supported metal ruthenium and then wash and dry the remaining alkali metal chloride with water. It is preferable that the alkali metal chloride contained at the time of firing is sufficiently washed with water. As a method of measuring the residual amount of the alkali metal chloride after washing, there is a method of adding an aqueous solution of silver nitrate to the filtrate and examining the presence or absence of cloudiness. However, alkali metal chlorides may remain as long as the catalytic activity of the present catalyst is not impaired.

It is a preferred preparation method that the washed catalyst is then dried. Drying conditions are preferably 50 to 2
00 ° C., preferably for 1 to 10 hours.

The supported ruthenium oxide catalyst produced by the above steps has high activity, and is excellent in a method for producing chlorine by oxidizing hydrogen chloride with oxygen.

A second example of the method for preparing a supported ruthenium oxide catalyst according to the present invention is a method in which a ruthenium compound supported on a carrier is treated with a reducing compound and then oxidized for preparation. Preferably, the method includes a step of treating a ruthenium compound supported on a carrier with a basic compound and a step of treating the ruthenium compound with a reducing compound, and then oxidizing and preparing the compound. More preferably, there is a method in which a ruthenium compound supported on a carrier is treated with an alkaline solution of a reducing compound and then oxidized to prepare the compound.

Examples of the ruthenium compound supported on the carrier include the same ruthenium compounds as those described in the first example of the method for preparing the supported ruthenium oxide catalyst.

Preferred ruthenium compounds include R
ruthenium chlorides such as uCl ₃ , RuCl ₃ hydrate,
Ruthenium halide compounds such as ruthenium bromide such as RuBr ₃ and RuBr ₃ hydrate are exemplified. More preferably, hydrated ruthenium chloride is used.

As a method for supporting a ruthenium compound on a carrier, there are an impregnation method, an equilibrium adsorption method and the like.

Examples of the reducing compound for treating the ruthenium compound supported on the carrier include hydrazine, methanol, ethanol, formaldehyde, hydroxylamine and formic acid. Or an aqueous solution of hydrazine, methanol, ethanol, formaldehyde, hydroxylamine or formic acid or a solution of an organic solvent such as alcohol, preferably a solution of hydrazine, methanol, ethanol, formaldehyde and hydrazine, methanol, ethanol, formaldehyde. And more preferably hydrazine and a solution of hydrazine. Further, as a reducing compound for treating a ruthenium compound supported on a carrier, the oxidation-reduction potential is -0.8 to 0.5.
Examples of the compound V include an aqueous solution thereof and a solution of an organic solvent such as alcohol. Here, the standard electrode potential is used instead of the oxidation-reduction potential. Of the compounds exemplified above, hydrazine shows -0.2
3V, formaldehyde is 0.056V, formic acid is-
0.199V. It is also a preferable method to use an aqueous alkali solution of a reducing compound.

The preparation method including the step of treating a ruthenium compound supported on a carrier with a basic compound is a preferred catalyst preparation method, and the basic compound used in the preparation is ammonia and alkylamine, pyridine, aniline, trimethylamine, Amines such as amines, alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and lithium hydroxide, alkali metal carbonates such as potassium carbonate, sodium carbonate and lithium carbonate, hydroxides of quaternary ammonium salts, triethylaluminum and the like And the like.

As a method of treating a ruthenium compound supported on a carrier with a reducing compound, the ruthenium compound is dried after the ruthenium compound is supported on the carrier and immersed in a reducing compound or a solution of the reducing compound, or Or a method of impregnating with a solution of a reducing compound. In addition, immersion in an alkaline aqueous solution of a reducing compound is also a preferred method.

The method of adding an alkali metal chloride after treating with a reducing compound or an aqueous alkali solution of the reducing compound is also a preferable method.

Next, as a method of oxidation, a method of firing in air is exemplified.

As a specific example of preparing the supported ruthenium oxide catalyst of the present invention, a preparation method including the following steps can be mentioned. Ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier Alkali treatment step: a step of adding an alkali to the one obtained in the ruthenium compound supporting step Reducing compound treatment step: The one obtained in the alkali treatment step is a reducing compound Treatment Step Oxidation step: Step of oxidizing the product obtained in the reducing compound treatment step In order to simultaneously perform the alkali treatment step and the reducing compound treatment step in the above steps, it is also a preferable method to use an aqueous alkali solution of the reducing compound. is there.

As a preferred specific example of preparing the supported ruthenium oxide catalyst of the present invention, a preparation method including the following steps can be mentioned. Ruthenium halide compound supporting step: Step of supporting ruthenium halide on a catalyst carrier Alkali treatment step: Step of adding an alkali to the one obtained in the ruthenium compound supporting step Reducing compound treatment step: Hydrazine obtained by the alkali treatment step Step of treating with methanol, ethanol or formaldehyde Oxidation step: Step of oxidizing the substance obtained in the step of treating the reducing compound

In order to simultaneously perform the alkali treatment step and the reducing compound treatment step in the above steps, it is also a preferable method to use an aqueous alkali solution of the reducing compound.

Further, as a more preferred specific example of preparing the supported ruthenium oxide catalyst of the present invention, a preparation method including the following steps can be mentioned. Ruthenium halide supporting step: Step of supporting ruthenium halide on a catalyst carrier Alkali treatment step: Step of adding an alkali to the one obtained in the ruthenium halide supporting step Hydrazine treatment step: Treating the one obtained in the alkali treatment step with hydrazine Step of adding an alkali metal chloride: Step of adding an alkali metal chloride to the substance obtained in the hydrazine treatment step Oxidation step: Step of oxidizing the substance obtained in the step of adding an alkali metal chloride

In order to simultaneously carry out the alkali treatment step and the hydrazine treatment step in the above steps, it is also a preferable method to use an aqueous solution of hydrazine in alkali.

The ruthenium halide supporting step is a step of supporting the ruthenium halide on the catalyst carrier. Examples of the ruthenium compound to be supported on the carrier include various ruthenium compounds described above.
ruthenium chlorides such as uCl ₃ and RuCl ₃ hydrate;
Preferred examples include ruthenium halides such as ruthenium bromide such as uBr ₃ and RuBr ₃ hydrate. Preferred ruthenium halides are RuCl
_3, RuCl ruthenium chloride such as ₃ hydrate, RuBr
_3, ruthenium bromide such as RuBr ₃ hydrate, and the like. More preferably, hydrated ruthenium chloride is used.

As the amount of ruthenium halide used in the ruthenium halide supporting step, an amount corresponding to a preferable weight ratio of ruthenium oxide to the carrier is usually used. That is, the catalyst carrier is supported on the catalyst carrier exemplified above by impregnating a solution of ruthenium halide or by equilibrium adsorption. As the solvent, an organic solvent such as water or alcohol is used, and preferably, water is used. Next, the impregnated material can be dried, or can be subjected to an alkali treatment without drying, but a method of drying is a preferred example. The condition for drying the impregnated material is preferably 50 to 200 ° C., and preferably 1 hour to 10 hours.

The alkali treatment step is a step of adding an alkali to the one obtained in the ruthenium halide supporting step.
The alkali used in the alkali treatment step is an alkali metal hydroxide, carbonate, bicarbonate, and ammonia,
Examples thereof include aqueous solutions of ammonium carbonate and ammonium hydrogen carbonate, and solutions of organic solvents such as alcohol. As the alkali, hydroxides, carbonates and bicarbonates of alkali metals are preferably used. Water is preferably used as the solvent. The concentration of the alkali varies depending on the alkali used, but is preferably 0.1 to 10 mol.
1 / l. The molar ratio of the ruthenium halide to the alkali is, for example, 3 moles equivalent to 1 mole of the ruthenium halide in the case of sodium hydroxide. You. Examples of a method of adding an alkali include a method of impregnating with an alkali solution and a method of immersing in an alkali solution. The time for impregnation with an alkali solution is usually within 60 minutes, but if the time for impregnation is long, the activity of the catalyst is reduced. The temperature is preferably 0 to 100 ° C, more preferably 10 to 60 ° C.

The hydrazine treatment step is a step of treating the product obtained in the alkali treatment step with hydrazine. As a method of treating with hydrazine, there is a method of impregnating with a hydrazine solution, dipping in a hydrazine solution, or the like. The supported ruthenium halide and the alkali solution which have been subjected to the alkali treatment in the previous step may be added to the hydrazine solution in a mixed state, or the alkali solution may be filtered and then added to the hydrazine solution. A preferred method is to impregnate the supported ruthenium halide with an alkali and then immediately add it to the hydrazine solution.
The concentration of hydrazine used in the hydrazine treatment step is:
Preferably, it is 0.1 mol / l or more, but hydrazine hydrate such as hydrazine monohydrate may be used as it is. Alternatively, it is used as a solution of an organic solvent such as alcohol. Preferably, an aqueous solution or hydrazine hydrate is used. Hydrazine can be an anhydride or a monohydrate. The molar ratio of ruthenium halide to hydrazine is preferably 0.1 to 2 of ruthenium halide.
0-fold molar is used. The time for immersion in the hydrazine solution is preferably 5 minutes to 5 hours, and more preferably 10 minutes to 2 hours. The temperature is preferably 0 to 100 ° C, more preferably 1 to 100 ° C.
0 to 60 ° C. Preferably, after immersion in the hydrazine solution, the catalyst is filtered off from the solution.

In order to simultaneously carry out the alkali treatment step and the hydrazine treatment step in the above steps, it is also a preferable method to use an aqueous solution of hydrazine in alkali. As a method,
As a preferred method, a method in which the obtained amount of the ruthenium halide supporting step is gradually added to a mixture of a preferred alkali amount and a preferred hydrazine amount in the form of an aqueous solution and the mixture is treated for 5 minutes to 5 hours is mentioned as a preferred method. Can be

As a more preferable method, the catalysts produced in the alkali treatment step and the hydrazine treatment step are washed to remove the alkali and hydrazine, dried, and the alkali metal chloride is added in the next alkali metal chloride addition step. After that, drying and oxidizing are mentioned.

A more preferred method is a method in which the catalyst produced in the alkali treatment step and the hydrazine treatment step is washed with an aqueous solution of an alkali metal chloride, dried and oxidized. This method is preferable because the removal of alkali and hydrazine and the addition of alkali metal chloride can be performed in the same step.

The step of adding an alkali metal chloride is a step of adding an alkali metal chloride to those obtained in the alkali treatment step and the hydrazine treatment step. Although this step is not an essential step for preparing a supported ruthenium oxide catalyst, the activity of the catalyst is further improved by performing this step. That is, the catalyst is oxidized in the next oxidation step, and in this case, it is preferable to convert the alkali-treated and hydrazine-treated catalyst in the presence of an alkali metal salt to convert the catalyst into highly active supported ruthenium oxide. It is.

Examples of the alkali metal chloride include alkali metal chlorides such as potassium chloride and sodium chloride, and are preferably potassium chloride, sodium chloride, and more preferably potassium chloride. Here, the molar ratio of alkali metal salt / ruthenium is preferably 0.01 to 10, more preferably 0.1 to 5.0. If the amount of the alkali metal salt is too small, a sufficiently high activity catalyst cannot be obtained.

As a method of adding the alkali metal chloride,
A method of impregnating the washed, dried alkali-treated and hydrazine-treated ruthenium catalyst with an aqueous solution of an alkali metal chloride can be mentioned. The method of washing and impregnating is more preferable.

For the purpose of adjusting the pH during washing of the catalyst, hydrochloric acid can be added to an aqueous solution of an alkali metal chloride. The concentration of the aqueous solution of the alkali metal chloride is preferably from 0.01 to 10 mol / l, more preferably from 0.1 to 5 mol / l.

The purpose of washing is to remove the alkali and hydrazine, but the alkali and hydrazine can be left as long as the effects of the present invention are not impaired.

After impregnation with the alkali metal chloride, the catalyst is usually dried. Drying conditions are preferably 50-200.
° C, preferably for 1 to 10 hours.

The oxidation step is a step of oxidizing the one obtained in the alkali treatment step and the hydrazine treatment step (when the alkali metal chloride addition step is not used), or the one obtained in the alkali metal chloride addition step. This is a step of oxidizing (when an alkali metal chloride adding step is used).
As the oxidation step, a method of firing in air can be mentioned. It is a preferable preparation example to oxidize to a highly active supported ruthenium oxide by calcining a substance subjected to an alkali treatment and a hydrazine treatment in a gas containing oxygen in the presence of an alkali metal salt. The gas containing oxygen usually includes air.

The firing temperature is preferably 100 to 600 ° C.
And more preferably 280 to 450 ° C. If the firing temperature is too low, a large amount of particles generated by the alkali treatment and the hydrazine treatment remain as the ruthenium oxide precursor, and the catalytic activity may be insufficient. Also, if the firing temperature is too high, aggregation of ruthenium oxide particles occurs,
Catalyst activity decreases. The firing time is preferably 30 minutes or more.
10 hours.

In this case, it is important to perform calcination in the presence of an alkali metal salt. By this method, finer particles of ruthenium oxide are produced, and higher catalytic activity can be obtained as compared with calcining in the substantial absence of an alkali metal salt.

By the calcination, the particles produced by the alkali treatment and hydrazine treatment carried on the carrier are converted into a supported ruthenium oxide catalyst. The conversion of the particles generated by the alkali treatment and the hydrazine treatment to ruthenium oxide can be confirmed by analysis such as X-ray diffraction or XPS (X-ray photoelectron spectroscopy). The particles generated by the alkali treatment and the hydrazine treatment are preferably substantially all converted to ruthenium oxide.However, as long as the effects of the present invention are not impaired, the particles generated by the alkali treatment and the hydrazine treatment are preferably used. May be allowed to remain.

A preferred preparation method is to subject the alkali-treated and hydrazine-treated ones to an oxidation treatment, and then to wash and dry the remaining alkali metal chloride. It is preferable that the alkali metal chloride contained at the time of firing is sufficiently washed with water. As a method of measuring the residual amount of the alkali metal chloride after washing, there is a method of adding an aqueous solution of silver nitrate to the filtrate and examining the presence or absence of cloudiness. However, alkali metal chlorides may remain as long as the catalytic activity of the present catalyst is not impaired.

It is a preferred preparation method that the washed catalyst is then dried. Drying conditions are preferably 50 to 2
00 ° C., preferably for 1 to 10 hours.

The supported ruthenium oxide catalyst produced by the above steps had high activity, and was more active than the catalyst prepared by oxidizing the catalyst obtained by reducing ruthenium chloride with hydrogen.
In addition, a catalyst which is subjected to hydrazine treatment with alkali pretreatment or oxidized after simultaneous alkali treatment and hydrazine treatment has a higher activity than a catalyst which is obtained by subjecting conventional ruthenium chloride to hydrazine treatment and oxidation treatment. there were.

Using the above catalyst of the present invention, chlorine can be obtained by oxidizing hydrogen chloride with oxygen. In obtaining chlorine, a reaction system such as a fixed bed or a fluidized bed is used as a reaction system, and a gas phase reaction such as a fixed bed gas phase flow system or a gas phase fluidized bed flow system is preferably employed. The fixed-bed type does not require the separation of the reaction gas and the catalyst, and has an advantage that a high conversion can be achieved because the contact between the raw material gas and the catalyst can be sufficiently performed. Further, the fluidized bed method has an advantage that the heat in the reactor can be sufficiently removed and the width of the temperature distribution in the reactor can be reduced.

When the reaction temperature is high, ruthenium oxide in a highly oxidized state is volatilized. Therefore, it is desirable to carry out the reaction at a lower temperature, preferably 100 to 500 ° C., more preferably 200 to 400 ° C. And more preferably 200 to 380 ° C. The reaction pressure is usually about atmospheric pressure to about 50 atm. As the oxygen source, air may be used as it is, or pure oxygen may be used,
Preferably, pure oxygen containing no inert gas is used because other components are simultaneously released when the inert nitrogen gas is released outside the apparatus. The theoretical molar amount of oxygen with respect to hydrogen chloride is 1/4 mole, but usually 0.1 to 10 times the theoretical amount is supplied. The amount of the catalyst used is usually about 10 to 20,000 h ^{-1 in} the case of the fixed bed gas phase flow system, expressed as a ratio GHSV to the feed rate of the raw material hydrogen chloride under atmospheric pressure.

[0081]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 A catalyst was prepared by the following method. That is, 53.4 g of titanium oxide powder (STR-60N, 100% rutile crystal system) and 33.4 g of pure water and titanium oxide sol (CSB of Sakai Chemical Co., 38% by weight of TiO ₂ ) 6. 6g
Was added and kneaded. The kneaded material was blown with dry air at room temperature, and dried until the carrier became clay-like. At this time, the amount of water reduced by drying was 0.2 g. This clay-like solid was extruded into a 1.5 mmφ noodle shape. Next, it was dried in the air at 60 ° C. for 4 hours to obtain 46.3 g of white noodle-like titanium oxide. Next, the temperature was raised in the air from room temperature to 500 ° C. in 1.3 hours, and baked at the same temperature for 3 hours. After the firing, the noodle-like solid was trimmed to a length of about 5 mm to obtain 45.3 g of a white rod-like titanium oxide carrier. Next, 40.0 g of this carrier was impregnated with 3.23 g of commercially available ruthenium chloride (RuCl ₃ .nH ₂ O, Ru content of 37.3 wt%) and an aqueous solution prepared by dissolving in 21.9 g of pure water, and then heated at 60 ° C. For 2 hours. Next, the obtained solid was immersed in a solution composed of 16.7 g of a 2N potassium hydroxide solution, 241 g of pure water, and 4.1 g of hydrazine monohydrate at room temperature. Foaming occurred upon soaking. After 80 minutes, 500 ml of pure water was added, washed for 30 minutes, and filtered. This operation was repeated five times. At this time, the pH of the first cleaning solution was 9.2, and the pH of the fifth cleaning solution was 7.2. 0.5 to the filtered catalyst
After adding 50 g of a mol / l potassium chloride solution and stirring, the catalyst was filtered off again. This operation was repeated three times. The obtained solid was dried at 60 ° C. for 4 hours to obtain a gray solid.
Next, the temperature was raised from room temperature to 350 ° C. in air for 1 hour, and baked at the same temperature for 3 hours. After calcination, 500 ml of pure water was added and stirred, and then the catalyst was separated by filtration. This operation is 1
The process was repeated 0 times, and an aqueous solution of silver nitrate was added dropwise to the washing solution, and it was confirmed that potassium chloride did not remain. Next, this catalyst was dried at 60 ° C. for 4 hours to obtain 41.1 g of a blue-gray rod-like titanium oxide-supported ruthenium oxide catalyst.
The calculated value of the ruthenium oxide content is calculated as RuO ₂ / (R
uO ₂ + TiO ₂ ) × 100 = 3.8% by weight. The calculated value of the ruthenium content is Ru / (RuO ₂ + TiO ₂ )
× 100 = 2.9% by weight. The titanium oxide powder used was subjected to X-ray diffraction analysis under the following conditions. Apparatus Rotorflex RU200B (manufactured by Rigaku Corporation) X-ray Cu Kα ray X-ray output 40 kV-40 mA Divergence slit 1 ° Scattering slit 1 ° Light receiving slit 0.15 mm Scanning speed 1 ° / min Scanning range 5.0-75.0 ° Counter Monochromator Curved crystal monochromator peak intensity of rutile crystal at 2θ = 27.4 ° 1389c
The peak intensity of the anatase crystal at 2θ = 25.3 ° with respect to ps was 40 cps, and the ratio of the rutile peak intensity to the total value was 97%. 2.5 g of the titanium oxide-supported ruthenium oxide catalyst thus obtained was placed on a commercially available α-alumina carrier having a diameter of 2 mm (manufactured by Nikkato Corp., SSA9
95) The catalyst was diluted by thoroughly mixing with 10 g, and filled in a quartz reaction tube (inner diameter: 12 mm). 192 ml / min of hydrogen chloride gas and 192 ml / mi of oxygen gas
n (all at 0 ° C., 1 atm) was supplied under normal pressure. The quartz reaction tube was heated in an electric furnace, and the internal temperature (hot spot) was set at 298 ° C. 2.3 hours after the start of the reaction, sampling was performed by flowing the gas at the outlet of the reaction tube through a 30% aqueous solution of potassium iodide, and the amount of chlorine produced and the amount of unreacted chloride were determined by iodine titration and neutralization titration, respectively. The amount of hydrogen was measured. The chlorine formation activity per unit catalyst weight determined by the following equation is 8.9 × 10 ⁻⁴ mol / min · g-
It was a catalyst. Chlorine formation activity per unit catalyst weight (mol / min · g
−catalyst) = amount of exit chlorine produced per unit time (mol / m
in) / catalyst weight (g)

Example 2 A catalyst was prepared by the following method. That is, 15.0 g of titanium oxide powder (STR-60N, 100% rutile crystal system) from commercially available ruthenium chloride (RuCl) was used.
₃ · nH ₂ O, Ru content 37.3 wt%) 2.01 g and 2
It was immersed in an aqueous solution consisting of 6.7 g of pure water, and then evaporated at 50 ° C. for 4 hours under vacuum evacuation. Next, 6
Dry at 0 ° C. for 2 hours. After drying, the catalyst was pulverized well to obtain a black powder. This powder was immersed in a solution consisting of 10.4 g of 2N potassium hydroxide solution, 69.9 g of pure water and 2.53 g of hydrazine monohydrate at room temperature. Foaming occurred upon soaking. During the treatment for one hour, the foamed gas was collected and the volume was measured, and it was 74 ml in a standard state. Next, 500 ml of pure water was added, and the resultant was washed for 30 minutes and then filtered. This operation was repeated five times. At this time, the pH of the first cleaning solution was 9.4, and the pH of the fifth cleaning solution was
Was 7.1. After adding 50 g of a 2 mol / l potassium chloride solution to the filtered catalyst powder and stirring, the catalyst powder was filtered again. This operation was repeated three times. The obtained cake was dried at 60 ° C. for 4 hours to obtain a black-brown powder. Next, in air, the temperature is raised from room temperature to 350 ° C. in one hour,
It baked at the same temperature for 3 hours. After calcination, 500 ml of pure water was added and stirred, and then the catalyst was separated by filtration. This operation was repeated five times, and an aqueous solution of silver nitrate was added dropwise to the washing solution, and it was confirmed that potassium chloride did not remain. The catalyst was then added to 6
By drying at 0 ° C. for 4 hours, 14.5 g of a black powder was obtained. The obtained powder was molded and made into a 8.6 to 16.0 mesh to obtain a titanium oxide-supported ruthenium oxide catalyst. The calculated value of the ruthenium oxide content is Ru
O ₂ / (RuO ₂ + TiO ₂ ) × 100 = 6.2% by weight. The calculated value of the ruthenium content is Ru / (RuO ₂
+ TiO ₂ ) × 100 = 4.7% by weight. Also,
The OH group content of the carrier was measured as follows. That is, the sample was previously dried in air at 150 ° C. for 2 hours, and then cooled in a desiccator. Thereafter, 1.06 g of the sample was transferred into a nitrogen-purged flask, and suspended in 40 ml of a dehydrated toluene solvent. The flask was cooled with ice to suppress heat generation, and 5 ml of methyllithium was dropped from the dropping funnel. As a result, 52 ml of methane gas was generated. When the same operation was performed without the sample, 30 ml of methane gas was generated. The temperature at this time was 24 ° C. Using the following formula (1), the OH group content Q (mol / g-
When the carrier was calculated, Q = (V−V ₀ ) / (22.4 × (273 + T) / 273) / W (1) V: amount of generated gas (ml) At the temperature T of methane gas generated during the measurement, V ₀ : Amount of blank generated gas (ml) Amount of methane gas at temperature T generated from residual moisture in the measurement system when measurement is performed without a measurement sample T: Measurement temperature (° C) W: Sample amount (g) ) 8.5 × 10 ⁻⁴ (mol / g-carrier). In the same manner as in Example 1, 2.5 g of the titanium oxide-supported ruthenium oxide catalyst thus obtained was used as in Example 1 for a quartz reaction tube (inner diameter 1
2 mm), and the reaction was performed in accordance with the reaction method of Example 1 except that the internal temperature was set to 300 ° C. 2.2 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 5.1.
× 10 ⁻⁴ mol / min · g-catalyst.

Example 3 A catalyst was prepared by the following method. That is, pure water 27
0.1g and 30wt% titanium sulfate solution (Wako Pure Chemical Industries)
134.0 g were mixed at room temperature. 10.0 g of titanium oxide powder (PT-101, 100% rutile crystal system, manufactured by Ishihara Sangyo Co., Ltd.) was mixed with the obtained solution at room temperature. Next, the obtained suspension was heated to 102 ° C. with stirring using an oil bath, and heated and hydrolyzed for 7 hours. After hydrolysis, the mixture was cooled to room temperature, left overnight, and then filtered. 0.5 L of pure water was added to the obtained white precipitate, washed for 30 minutes, and filtered. This operation was repeated eight times. Next, the obtained precipitate was dried at 60 ° C. for 4 hours to obtain 25.0 g of a white powder. The powder was heated to 300 ° C. in air for 1 hour and calcined at the same temperature for 5 hours to obtain 23.2 g of a white solid. Further, 20.2 g of this powder was fractionated, heated to 500 ° C. in air for 1.4 hours, and calcined at the same temperature for 3 hours to obtain 19.5 g of a white solid. . The obtained solid was pulverized to obtain a titanium oxide powder. Commercially available ruthenium chloride (RuCl ₃ .nH ₂ O, Ru content 3) was added to 9.5 g of the obtained titanium oxide powder in advance.
(7.3 wt%), immersed in an aqueous solution composed of 1.27 g and 9.5 g of pure water, and then evaporated at 40 ° C. for 2 hours under vacuum evacuation. Next, it dried at 60 degreeC for 2 hours. After drying, the catalyst was thoroughly pulverized in a mortar to obtain a black powder. This powder was placed in a nitrogen solution at room temperature in nitrogen at 6.6.
g of pure water and 28.5 g of pure water, and stirred in a nitrogen atmosphere. One minute later, a solution consisting of 1.83 g of hydrazine monohydrate and 4.8 g of pure water was added to the stirring suspension, and the suspension was treated with hydrazine. Foaming occurred upon addition. One hour later, 500 ml of pure water was added, washed for 30 minutes, and filtered. This operation was repeated five times. At this time, the pH of the first cleaning solution was 8.2, and the pH of the fifth cleaning solution was
Was 6.6. 48 g of a 2 mol / l potassium chloride solution was added to the filtered catalyst powder and stirred, and then the catalyst powder was filtered again. This operation was repeated three times. The obtained cake was dried at 60 ° C. for 4 hours to obtain 10.2 g of a black powder. Next, the temperature was raised from room temperature to 350 ° C. in air for 1 hour, and baked at the same temperature for 3 hours. After firing, 500ml
After adding pure water and stirring, the catalyst was filtered off. This operation was repeated five times, and an aqueous solution of silver nitrate was added dropwise to the washing solution, and it was confirmed that potassium chloride did not remain. Next, 8.93 g of this catalyst was dried at 60 ° C. for 4 hours.
Was obtained as a black powder. The obtained powder was molded, and 8.6 to 1
By setting the mesh size to 6.0, a ruthenium oxide catalyst supporting titanium oxide was obtained. The calculated value of the ruthenium oxide content was calculated as RuO ₂ / (RuO ₂ + TiO ₂ ) × 100 = 6.2.
% By weight. The calculated value of the ruthenium content is Ru /
(RuO ₂ + TiO ₂ ) × 100 = 4.7% by weight. The titanium oxide powder used was subjected to X-ray diffraction analysis under the same conditions as in Example 1. As a result, the peak intensity of rutile crystal at 2θ = 27.4 ° was 1497 cps, and 2θ = 25.
No peak intensity of the anatase crystal at 3 ° was observed, and the ratio of the rutile peak intensity was 100%. The OH group content of the carrier was measured under the same conditions as in Example 2 except that the sample amount was changed to 2.36 g. As a result, 54 ml of methane gas was generated. The OH group content of the carrier is 3.7 × 10 ⁻⁴ (m
ol / g-carrier). 2.5 g of the titanium oxide-supported ruthenium oxide catalyst thus obtained was charged into a quartz reaction tube (inner diameter: 12 mm) in the same manner as in Example 1, and hydrogen chloride gas was introduced at 211 ml / min, and oxygen gas was introduced at 211 ml / min.
The reaction was carried out in accordance with the reaction method of Example 1 except that the mixture was circulated at a minimum temperature of 300 ° C. 2.3 hours after the start of the reaction, the chlorine generation activity per unit catalyst weight was 8.2.
× 10 ⁻⁴ mol / min · g-catalyst.

Example 4 A catalyst was prepared by the following method. That is, a titanium oxide powder (Sakai Chemical Co., Ltd., 100% rutile crystal form) was previously heated in air from room temperature to 500 ° C. for 1.4 hours, and calcined at the same temperature for 3 hours. Then fired 1
0.0 g of commercially available ruthenium chloride (RuCl ₃ .nH
₂ O, Ru content 37.3wt%) 1.34g and 17.8
g of pure water, and then evaporated at 40 ° C. for 2 hours under vacuum evacuation. Next, at 60 ° C
For 2 hours. After drying, the catalyst was pulverized well to obtain a black-brown powder. This powder was immersed in a solution consisting of 6.9 g of a 2N potassium hydroxide solution and 30.0 g of pure water in nitrogen at room temperature and stirred. One minute later, hydrazine 1 was added to the stirring suspension.
A solution consisting of 1.93 g of hydrate and 5.0 g of pure water was added,
Treated with hydrazine. Foaming occurred upon addition.
One hour later, 500 ml of pure water was added, washed for 30 minutes, and filtered. This operation was repeated five times. At this time, the pH of the first washing solution was 8.7, and the pH of the fifth washing solution was p.
H was 7.4. 2mol / l to the filtered catalyst powder
After adding 50 g of a potassium chloride solution and stirring, the catalyst powder was filtered off again. This operation was repeated three times. The obtained cake was dried at 60 ° C. for 4 hours to obtain a black powder. Next, in air, the temperature is raised from room temperature to 350 ° C. in one hour,
It baked at the same temperature for 3 hours. After calcination, 500 ml of pure water was added and stirred, and then the catalyst was separated by filtration. This operation was repeated five times, and an aqueous solution of silver nitrate was added dropwise to the washing solution, and it was confirmed that potassium chloride did not remain. The catalyst was then added to 6
By drying at 0 ° C. for 4 hours, 9.7 g of a black powder was obtained. The obtained powder was molded and made into a 8.6 to 16.0 mesh to obtain a titanium oxide-supported ruthenium oxide catalyst. The calculated value of the ruthenium oxide content is RuO
₂ / (RuO ₂ + TiO ₂ ) × 100 = 6.2% by weight. The calculated value of the ruthenium content is Ru / (RuO ₂ +
TiO ₂ ) × 100 = 4.7% by weight. X-ray diffraction analysis of the used titanium oxide powder under the same conditions as in Example 1 showed that the peak intensity of the rutile crystal at 2θ = 27.4 ° was 907 cps and the peak of the anatase crystal at 2θ = 25.3 °. No intensity was observed, and the ratio of the rutile peak intensity was 100%. The OH group content of the carrier was measured under the same conditions as in Example 2 except that the sample amount was 1.64 g, and 54 ml of methane gas was generated. The OH group content of the carrier was 6.0 × 10 ⁻⁴ (mol / g-carrier). 2.5 g of the titanium oxide-supported ruthenium oxide catalyst thus obtained was charged into a quartz reaction tube (inner diameter: 12 mm) in the same manner as in Example 1, and hydrogen chloride gas was added to the reaction tube.
The reaction was performed in accordance with the reaction method of Example 1 except that 1 ml / min and oxygen gas were passed at 211 ml / min and the internal temperature was set to 300 ° C. 1.8 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 7.9 × 10 ⁻⁴ mo.
1 / min · g-catalyst.

Comparative Example 1 A catalyst was prepared by the following method. That is, commercially available ruthenium chloride (RuCl ₃ .nH ₂ O, 10.0 g of titanium oxide powder (P25, manufactured by Nippon Aerosil Co., Ltd.)
(Ru content: 37.3 wt%) was impregnated with an aqueous solution prepared by dissolving 1.34 g in 4.8 g of pure water.
Dried for hours. After drying, the catalyst was thoroughly pulverized in a mortar to obtain a black powder. In order to reduce this powder with sodium borohydride, a solution in which 1.66 g of sodium borohydride was dissolved in 330 g of ethanol was prepared, and cooled in an ice bath. To this sodium borohydride solution, the total amount of titanium oxide supporting ruthenium chloride was added with stirring. Foaming occurred upon addition. After 1 hour, the supernatant was removed by decantation. Next, 500 ml of pure water was added, washed for 30 minutes, and filtered. This operation was repeated nine times. At this time, the pH of the first washing solution was 9.
The pH of the sixth and ninth washings was 7.7. The obtained cake was dried at 60 ° C. for 4 hours to obtain a black powder. Next, 1.22 g of potassium chloride and pure water were added to the obtained powder.
An aqueous solution consisting of 7 g was impregnated. Next, the temperature was raised from room temperature to 350 ° C. in air for 1 hour, and baked at the same temperature for 3 hours. After calcination, 500 ml of pure water was added and stirred, and then the catalyst was separated by filtration. This operation was repeated five times, and an aqueous solution of silver nitrate was added dropwise to the washing solution, and it was confirmed that potassium chloride did not remain. Next, the catalyst was dried at 60 ° C. for 4 hours to obtain 9.5 g of a black powder. The obtained powder was molded and made into a 8.6 to 16.0 mesh to obtain a titanium oxide-supported ruthenium oxide catalyst. In addition,
The calculated value of the ruthenium oxide content is RuO ₂ / (RuO ₂ +
TiO ₂ ) × 100 = 6.2% by weight. The calculated value of the ruthenium content is Ru / (RuO ₂ + TiO ₂ ) × 10
0 = 4.7% by weight. X-ray diffraction analysis of the used titanium oxide powder under the same conditions as in Example 1 showed that
Peak intensity of rutile crystal at θ = 27.4 ° 381 cps
And peak intensity of anatase crystal at 2θ = 25.3 ° 19
The ratio of the rutile peak intensity to the total value of 14 cps was 17%. From now on, the ratio of rutile crystals is 17%
Met. The sample amount was 4.08 g and the toluene amount was 8
OH of the carrier under the same conditions as in Example 2 except that the volume was 0 ml.
When the group content was measured, 88 ml of methane gas was generated. The OH group content of the carrier was 2.8 × 10 ⁻⁴ (mol /
g-carrier). 2.5 g of the titanium oxide-supported ruthenium oxide catalyst obtained in this manner was added to a commercially available titanium oxide carrier (Sakai Chemical CS-300S-12) having a diameter of 1 to 2 mm.
g, and the catalyst was diluted. The mixture was filled into a reaction tube in the same manner as in Example 1, and hydrogen chloride gas was supplied at 195 ml / m 2.
in, oxygen gas was flowed at 198 ml / min, and the internal temperature was set to 299 ° C., and the procedure was performed in accordance with Example 1. 2.0 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 4.31 × 10 ⁻⁴ mol / min · g-catalyst.

Comparative Example 2 A catalyst was prepared by the following method. That is, commercially available ruthenium chloride (RuCl ₃ .nH ₂ O,
(Ru content: 37.3 wt%) was impregnated with an aqueous solution prepared by dissolving 0.41 g in 3.5 g of pure water.
Dried for hours. After drying, the catalyst was thoroughly pulverized in a mortar to obtain a dark green powder. In order to reduce this powder with sodium borohydride, sodium borohydride is added.
A solution in which 50 g was dissolved in 100.0 g of ethanol was prepared, and cooled in an ice bath. To this sodium borohydride solution, the total amount of titanium oxide supporting ruthenium chloride was added with stirring. Foaming occurred upon addition. After 1 hour, the supernatant was removed by decantation. Next, 500 ml of pure water was added, washed for 30 minutes, and filtered. This operation was repeated five times. At this time, the pH of the first cleaning solution was 9.3, and the pH of the fifth cleaning solution was 4.2. A 2 mol / l potassium chloride solution was added to the filtered catalyst powder and stirred, and then the catalyst powder was filtered again. This operation was repeated three times. The amount of the added potassium chloride solution was 48.1 g for the first time, 52.9 g for the second time, and 47.
2 g. The obtained cake was dried at 60 ° C. for 4 hours to obtain a gray powder. Then, in air, from room temperature to 35
The temperature was raised to 0 ° C. in 1 hour and calcined at the same temperature for 3 hours. After calcination, 500 ml of pure water was added and stirred, and then the catalyst was separated by filtration. This operation was repeated five times, and an aqueous solution of silver nitrate was added dropwise to the washing solution, and it was confirmed that potassium chloride did not remain. Next, the catalyst was dried at 60 ° C. for 4 hours to obtain 9.2 g of a blue-gray powder. The obtained powder was molded and made into a 8.6 to 16.0 mesh to obtain a titanium oxide-supported ruthenium oxide catalyst. The calculated value of the ruthenium oxide content is calculated as RuO ₂ / (RuO ₂ + TiO ₂ )
× 100 = 1.9% by weight. The calculated value of the ruthenium content is Ru / (RuO ₂ + TiO ₂ ) × 100 = 1.5
% By weight. The catalyst was diluted by thoroughly mixing 2.5 g of the titanium oxide-supported ruthenium oxide catalyst thus obtained with 5 g of a commercially available titanium oxide carrier (Sakai Chemical CS-300S-12) having a diameter of 1 to 2 mm. Filled into a quartz reaction tube in the same manner as in 1, and hydrogen chloride gas was supplied at 195 ml / m
The reaction was carried out in the same manner as in Example 1 except that in and oxygen gas were passed at 198 ml / min and the internal temperature was set to 300 ° C. 2.0 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 5.56 × 10 ⁻⁴ mol / min ·
g-catalyst.

Comparative Example 3 A catalyst was prepared by the following method. That is, commercially available ruthenium chloride (RuCl ₃ .nH ₂ O,
Ru content: 37.3 wt%) was impregnated with an aqueous solution prepared by dissolving 0.40 g in 3.4 g of pure water.
Dried for hours. After drying, the catalyst was thoroughly pulverized in a mortar to obtain a dark green powder. This powder was immersed in a solution consisting of 2.1 g of 2N potassium hydroxide solution and 30.2 g of pure water at room temperature, and stirred while the flask was placed in an ultrasonic cleaner. One minute later, the hydrazine monohydrate was added to the suspension while stirring.
A solution consisting of 59 g and 5.1 g of pure water was added and treated with hydrazine. Foaming occurred upon addition. 15 minutes later,
After adding 500 ml of pure water and washing for 30 minutes, it was filtered off. This operation was repeated five times. At this time, the pH of the first cleaning solution was 7.8, and the pH of the fifth cleaning solution was 6.0.
Met. A 2 mol / l potassium chloride solution was added to the filtered catalyst powder and stirred, and then the catalyst powder was filtered again.
This operation was repeated three times. The amount of the added potassium chloride solution was 53.6 g for the first time, 62.4 g for the second time, and 3 times for the third time.
It was 9.4 g. The obtained cake was dried at 60 ° C. for 4 hours to obtain a beige powder. Next, the temperature was raised from room temperature to 350 ° C. in air for 1 hour, and baked at the same temperature for 3 hours. After firing, add 500 ml of pure water and stir,
The catalyst was filtered off. This operation was repeated five times, and an aqueous solution of silver nitrate was added dropwise to the washing solution, and it was confirmed that potassium chloride did not remain. Then, the catalyst was dried at 60 ° C. for 4 hours to obtain 8.4 g of a blue-gray powder. The obtained powder was molded and made into a 8.6 to 16.0 mesh to obtain a titanium oxide-supported ruthenium oxide catalyst. In addition,
The calculated value of the ruthenium oxide content is RuO ₂ / (RuO ₂ +
TiO ₂ ) × 100 = 1.9% by weight. The calculated value of the ruthenium content is Ru / (RuO ₂ + TiO ₂ ) × 10
0 = 1.4% by weight. 2.5 g of the titanium oxide-supported ruthenium oxide catalyst obtained in this way was
Commercially available titanium oxide carrier of spheres (Sakai Chemical CS-300S-1
2) The catalyst was diluted by thoroughly mixing with 5 g, and charged into a reaction tube in the same manner as in Example 1.
1 / min, oxygen gas was passed at 199 ml / min, and the reaction was carried out in accordance with the reaction method of Example 1 except that the internal temperature was 301 ° C. 2.0 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 5.33 × 10 ⁻⁴ mo.
1 / min · g-catalyst.

Comparative Example 4 A catalyst was prepared by the following method. That is, commercially available ruthenium chloride (RuCl ₃ .nH ₂ O, P25) was previously added to 19.7 g of titanium oxide powder (P25, manufactured by Nippon Aerosil Co., Ltd.).
(Ru content: 37.3 wt%) was impregnated with an aqueous solution prepared by dissolving 0.81 g in 6.0 g of pure water.
Dried for hours. After drying, the catalyst was thoroughly pulverized in a mortar to obtain a dark green powder. To reduce this powder with sodium borohydride sodium borohydride 1.
A solution in which 00 g was dissolved in 199.7 g of ethanol was prepared, and cooled in an ice bath. To this sodium borohydride solution, the total amount of titanium oxide supporting ruthenium chloride was added with stirring. Foaming occurred upon addition. After 1 hour, the supernatant was removed by decantation. Next, 500 ml of pure water was added, washed for 30 minutes, and filtered. This operation was repeated five times. At this time, the pH of the first cleaning solution was 9.8, and the pH of the fifth cleaning solution was 6.6. The obtained cake was dried at 60 ° C. for 4 hours. 18.0 g of a blue-gray powder were obtained. Next, the obtained powder was impregnated with an aqueous solution consisting of 0.66 g of potassium chloride and 9.0 g of pure water, and dried at 60 ° C. Next, the temperature was raised from room temperature to 350 ° C. in air for 1 hour, and baked at the same temperature for 3 hours. After calcination, 500 ml of pure water was added and stirred, and then the catalyst was separated by filtration. This operation was repeated five times, and an aqueous solution of silver nitrate was added dropwise to the washing solution, and it was confirmed that potassium chloride did not remain. Next, the catalyst was dried at 60 ° C. for 4 hours to obtain 17.3 g of a blue-gray powder. The obtained powder was molded and made into a 8.6 to 16.0 mesh to obtain a titanium oxide-supported ruthenium oxide catalyst. In addition,
The calculated value of the ruthenium oxide content is RuO ₂ / (RuO ₂ +
TiO ₂ ) × 100 = 2.0% by weight. The calculated value of the ruthenium content is Ru / (RuO ₂ + TiO ₂ ) × 10
0 = 1.5% by weight. 2.5 g of the titanium oxide-supported ruthenium oxide catalyst obtained in this way was
Commercially available titanium oxide carrier of spheres (Sakai Chemical CS-300S-1
2) The catalyst was diluted by mixing well with 5 g, and charged into a reaction tube as in Example 1;
1 / min, oxygen gas was passed at 198 ml / min, and the reaction was performed in accordance with the reaction method of Example 1 except that the internal temperature was set to 299 ° C. 2.0 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 4.41 × 10 ⁻⁴ mo.
1 / min · g-catalyst.

Comparative Example 5 A catalyst was prepared by the following method. That is, commercially available ruthenium chloride hydrate (RuCl ₃ .3H ₂ O, Ru content 3
(5.5%) 0.70 g was dissolved in 4.0 g of water. After stirring the aqueous solution well, it is adjusted to 12-18.5 mesh,
It was added dropwise to 5.0 g of silica (Caractact G-10, manufactured by Fuji Silysia K.K.) dried at 500 ° C. for 1 hour in the air, and ruthenium chloride was impregnated thereon. The supported material was heated from room temperature to 100 ° C. for 30 minutes under a nitrogen stream of 100 ml / min, dried at the same temperature for 2 hours, and allowed to cool to room temperature to obtain a black solid. 100 ml of the obtained solid
1 hour 3 from room temperature to 250 ° C under an air flow of / min3
The temperature was raised in 0 minutes, dried at the same temperature for 3 hours, and allowed to cool to room temperature to obtain 5.37 g of a black silica-supported ruthenium chloride catalyst. The calculated value of the ruthenium content is Ru /
(RuCl ₃ .3H ₂ O + SiO ₂ ) × 100 = 4.5% by weight. The silica-supported ruthenium chloride catalyst (2.5 g) thus obtained was filled in a reaction tube in the same manner as in Example 1 without diluting, and hydrogen chloride was supplied at a gas flow of 202 ml / min.
Oxygen gas is circulated at 213 ml / min and the internal temperature is 30
The procedure was performed in accordance with Example 1 except that the temperature was changed to 1 ° C. 1.7 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 0.49 × 10 ⁻⁴ mol / min · g-catalyst.

Comparative Example 6 A catalyst was prepared by the following method. That is, 8.0 g of spherical titanium oxide (manufactured by Sakai Chemical Industry Co., Ltd., CS-300) pulverized in a mortar and powdered, and 0.53 g of ruthenium dioxide powder (manufactured by NE Chemcat Co., Ltd.) were mortared. After mixing well with grinding, the mixture was formed into a mesh of 12 to 18.5 mesh to obtain a mixed catalyst of ruthenium oxide and titanium oxide. The calculated value of the ruthenium oxide content was 6.2% by weight.
Met. The calculated value of the ruthenium content was 4.7% by weight. The catalyst was diluted by thoroughly mixing 2.5 g of the thus-obtained ruthenium oxide titanium oxide mixed catalyst with 5 g of a commercially available titanium oxide carrier (Sakai Chemical CS-300S-12) having 1-2 mm spheres. In the same manner as in Example 1, the reaction tube was filled, hydrogen chloride gas was passed at 199 ml / min, oxygen gas was passed at 194 ml / min, and the internal temperature was set at 299 ° C., and the procedure was performed in accordance with Example 1. 2.3 hours after the start of the reaction, the activity of forming chlorine per unit catalyst weight was as follows:
It was 0.83 × 10 ⁻⁴ mol / min · g-catalyst.

Comparative Example 7 A catalyst was prepared by the following method. That is, 41.7 g of commercially available tetraethyl orthosilicate was dissolved in 186 ml of ethanol, and 56.8 g of titanium tetraisopropoxide was added while stirring at room temperature, followed by stirring at room temperature for 30 minutes. Next, an aqueous solution in which 93 ml of ethanol was well mixed with a 0.01 mol / l acetic acid aqueous solution prepared by dissolving 0.14 g of acetic acid in 233 ml of pure water was dropped into the above solution. A white precipitate formed as the solution was added. After the completion of the dropwise addition, the mixture was stirred at room temperature for 30 minutes, heated with stirring, and refluxed for 1 hour on a 102 ° C. oil bath. The liquid temperature at this time was 80 ° C. Next, the solution was allowed to cool, and then filtered through a glass filter.
, And filtered again. After repeating this operation twice, it is dried in air at 60 ° C. for 4 hours, and is dried at room temperature to 550 ° C.
The temperature was raised in 1 hour until the temperature was increased, and the mixture was calcined at the same temperature for 3 hours to obtain 27.4 g of a white solid. The obtained solid was pulverized to obtain titania silica powder. A commercially available ruthenium chloride hydrate (R) was added to 8.0 g of the obtained titania silica powder.
1.13 g of uCl ₃ .3H ₂ O, Ru content 35.5%)
Was dissolved in 8.2 g of water and then impregnated with
After drying at 1 ° C. for 1 hour, ruthenium chloride was supported. Next, the carrier was loaded with 50 ml / min of hydrogen and 100 ml / min of nitrogen.
min from a room temperature to 300 ° C for 1 hour 30
Then, the mixture was reduced at the same temperature for 1 hour, and then allowed to cool to room temperature to obtain 8.4 g of a grayish brown titania silica-supported metal ruthenium powder. 8.4 g of the obtained titania silica-supported metal ruthenium powder was heated from room temperature to 600 ° C. for 3 hours and 20 minutes in an air stream of 100 ml / min, and calcined at the same temperature for 3 hours to obtain 8.5 g of the powder. A gray powder was obtained. The obtained powder was molded and made to have a mesh size of 12 to 18.5 to obtain a ruthenium oxide catalyst supported on titania silica. The calculated value of the ruthenium oxide content is Ru
O ₂ / (RuO ₂ + TiO ₂ + SiO ₂ ) × 100 = 6.2
% By weight. The calculated value of the ruthenium content is Ru /
(RuO ₂ + TiO ₂ + SiO ₂ ) × 100 = 4.7% by weight. The titania silica-supported ruthenium oxide catalyst (2.5 g) thus obtained was not diluted but filled in a reaction tube in the same manner as in Example 1, and hydrogen chloride gas was supplied at 180 ml / mi.
n and oxygen gas were passed at 180 ml / min, and the reaction was carried out in accordance with the reaction method of Example 1 except that the internal temperature was set to 300 ° C. 1.8 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst is 0.46 × 10 ⁻⁴ mol / min.
G-catalyst.

Comparative Example 8 A catalyst was prepared by the following method. That is, 1-2 mm
φ spherical titanium oxide carrier (manufactured by Sakai Chemical Industry, CS-30
OSS-12) 10.1 g of an aqueous solution prepared by previously dissolving 1.34 g of commercially available ruthenium chloride (RuCl ₃ .nH ₂ O, Ru content 37.3% by weight) in 3.74 g of pure water was impregnated. Then, it was dried in air at 60 ° C. for 4 hours. A dark brown solid was obtained. In order to reduce this solid with hydrogen, hydrogen (20 ml / min) and nitrogen (200 ml / min) were used.
/ Min) in a mixed gas flow from room temperature to 250 ° C over 2 hours, and reduced at the same temperature for 8 hours. After reduction 10.3g
Of a black solid was obtained. Next, the obtained solid was heated to 350 ° C. in air for 1 hour, and calcined at the same temperature for 3 hours. 10.6 g of a black catalyst were obtained. The calculated value of the ruthenium oxide content is calculated as RuO ₂ / (RuO ₂ + Ti
O ₂ ) × 100 = 6.1% by weight. The calculated value of the ruthenium content is Ru / (RuO ₂ + TiO ₂ ) × 100 =
It was 4.7% by weight. Further, as a result of performing an X-ray diffraction analysis of the used titanium oxide powder under the same conditions as in Example 1,
Peak intensity 182 of anatase crystal at 2θ = 25.3 °
For 4 cps, no peak of the rutile crystal at 2θ = 27.4 ° was observed, indicating that the ratio of the rutile crystal was 0%. The catalyst was diluted by thoroughly mixing 2.5 g of the titanium oxide-supported ruthenium oxide catalyst thus obtained with 5 g of a commercially available titanium oxide carrier (Sakai Chemical CS-300S-12) having a diameter of 1 to 2 mm. In the same manner as in Example 1, the reaction tube was filled, hydrogen chloride gas was passed at 187 ml / min, oxygen gas was flowed at 199 ml / min, and the internal temperature was 300 ° C., and the procedure was performed in accordance with Example 1. 2.0 hours after the start of the reaction, the activity of forming chlorine per unit catalyst weight was 2.
It was 89 × 10 ⁻⁴ mol / min · g-catalyst.

Comparative Example 9 A catalyst was prepared by the following method. That is, 1-2 mm
0.5 g of 10.0 g of a 5 wt% supported metal ruthenium titanium oxide catalyst (manufactured by NE Chemcat Co., Ltd.)
The catalyst was impregnated with an aqueous ol / l potassium chloride solution until water appeared on the surface of the catalyst, and dried in air at 60 ° C. for 1 hour.
This operation was repeated twice. The impregnation amount of the aqueous potassium chloride solution was 3.31 g for the first time and 3.24 g for the second time, and the total was 6.
55 g. The calculated value of the molar ratio of potassium chloride to ruthenium was 0.66. Dry in air 3
The temperature was raised to 50 ° C. in 1 hour and calcined at the same temperature for 3 hours.
Next, the obtained solid was washed with 500 ml of pure water for 30 minutes and filtered. This operation was repeated five times. An aqueous solution of silver nitrate was added dropwise to the filtrate, and it was confirmed that potassium chloride did not remain. After washing, the solid was dried at 60 ° C. for 4 hours to obtain 9.9 g of a spherical black titanium oxide-supported ruthenium oxide catalyst. The calculated value of the content of ruthenium oxide is calculated as follows: RuO ₂ / (RuO ₂ + TiO ₂ ) × 100 = 6.
It was 6% by weight. The calculated value of the ruthenium content is Ru /
(RuO ₂ + TiO ₂ ) × 100 = 5.0% by weight. The catalyst was diluted by thoroughly mixing 2.5 g of the titanium oxide-supported ruthenium oxide catalyst thus obtained with 5 g of a commercially available titanium oxide carrier (Sakai Chemical CS-300S-12) having a diameter of 1 to 2 mm. A quartz reaction tube (inner diameter 12 mm) was filled in the same manner as in Example 1 and hydrogen chloride gas was supplied for 187 m
1 / min, oxygen gas was passed at 199 ml / min, and the reaction was performed in accordance with the reaction method of Example 1 except that the internal temperature was set to 300 ° C. 2.0 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 4.03 × 10 ⁻⁴ mo.
1 / min · g-catalyst.

Comparative Example 10 A catalyst was prepared by the following method. That is, 0.81 g of commercially available ruthenium chloride (RuCl ₃ .nH ₂ O, Ru content: 37.3 wt%) is dissolved in 6.4 g of pure water to prepare an aqueous solution, and titanium oxide powder (manufactured by Nippon Aerosil Co., Ltd .; P25) 20.0 g. Next, at 60 ° C., 2
Dried for hours. After drying, the catalyst was thoroughly pulverized in a mortar to obtain 20.3 g of a dark green powder. This operation was repeated 9 times to obtain 183.8 g of a dark green powder. Next, 10.4 g of this powder was immersed in a mixed solution of 2.1 g of potassium hydroxide solution adjusted to 2N at room temperature and 30.1 g of pure water in an ultrasonic cleaner for 1 minute. Next, a solution consisting of 0.61 g of a hydrazine monohydrate solution and 5.0 g of pure water was poured into the suspension of the immersed solution and the solution at room temperature while applying ultrasonic waves in nitrogen. Foaming was observed in the solution upon pouring. After standing for 15 minutes until the firing disappeared, the supernatant was removed by filtration.
Next, 500 ml of pure water was added, washed for 30 minutes, and filtered. This operation was repeated five times. At this time, the pH of the first cleaning solution was 9.1, and the pH of the fifth cleaning solution was 7.
It was 4. A 2 mol / l potassium chloride solution was added to the filtered catalyst powder and stirred, and then the catalyst powder was filtered again. This operation was repeated three times. The amount of the potassium chloride solution added was 54.4 g for the first time, 52.1 g for the second time, and 52.9 g for the third time. The procedure from the operation of dipping in the potassium hydroxide solution was similarly repeated six times to obtain 107.1 g of a cake. 53.1 g of the obtained cake was dried at 60 ° C. for 4 hours to obtain 34.1 g of a gray powder. Then, the temperature is raised from room temperature to 350 ° C. in air for one hour, and
Fired for hours. After calcination, 500 ml of pure water was added and stirred, and then the catalyst was separated by filtration. Repeat this operation 21 times,
An aqueous solution of silver nitrate was added dropwise to the washing solution, and it was confirmed that potassium chloride did not remain. The catalyst was then treated at 60 ° C. for 4 hours.
After drying for 2 hours, 28.0 g of a blue-gray powder was obtained. The obtained powder was molded and made into a 8.6 to 16.0 mesh to obtain a titanium oxide-supported ruthenium oxide catalyst. The calculated value of the ruthenium oxide content was calculated as RuO ₂ /
(RuO ₂ + TiO ₂ ) × 100 = 1.9% by weight. The calculated value of the ruthenium content is Ru / (RuO ₂ + T
iO ₂ ) × 100 = 1.5% by weight. 17. The titanium oxide-supported ruthenium oxide catalyst thus obtained.
8 g was filled into the same glass reaction tube divided into two zones. The inner diameter of the glass reaction tube is 15 mm and the inner diameter is 6
mm thermocouple protection tube was placed. The upper zone is a commercially available α-alumina carrier having 5.9 g of titanium oxide-supported ruthenium oxide catalyst and 2 mm spheres (Nikkato Co., Ltd., SSA995).
The catalyst was diluted and charged by mixing 23.6 g well. The lower zone was charged undiluted with 11.9 g of ruthenium oxide catalyst supported on titanium oxide. Hydrogen chloride gas was supplied at a flow rate of 96 ml / min, and oxygen gas was supplied from an upper part to a lower part under normal pressure of 53 ml / min (both at 0 ° C. and 1 atm). The upper zone of the glass reaction tube was heated with an electric furnace, and the internal temperature (hot spot) was set to 361 ° C. Similarly, the internal temperature (hot spot) of the lower zone was set to 295 ° C. 4.5 hours after the start of the reaction, sampling was carried out by flowing the gas at the outlet of the reaction tube through a 30% aqueous solution of potassium iodide, and the amount of chlorine produced and the unreacted chloride were measured by iodine titration and neutralization titration, respectively. The amount of hydrogen was measured. As a result, the conversion of hydrogen chloride was 93.0%. In addition, 146 ml / min of hydrogen chloride gas and 74 ml / min of oxygen gas (both at 0 ° C. and 1 atm) are supplied under normal pressure, the internal temperature of the upper zone is set to 360 ° C., and the internal temperature of the lower zone is set. When the reaction was carried out in accordance with the above-mentioned reaction method except that the temperature was changed to 300 ° C, the conversion of hydrogen chloride was 91.6% 4.5 hours after the start of the reaction.

[0096]

As described above, according to the present invention, there is provided a supported ruthenium oxide catalyst for producing chlorine by oxidizing hydrogen chloride, which has a high activity and produces a target compound at a lower reaction temperature with a smaller amount of catalyst. A possible catalyst could be provided.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takahiro Oizumi 6 Kitahara, Tsukuba, Ibaraki Sumitomo Chemical Co., Ltd. F-term (reference) 4G069 AA03 AA08 BA04A BA04B BC70A BC70B BD12A BD12B CB07 EC22X FA02 FB39 FB43

Claims (12)

[Claims] 1. A supported ruthenium oxide catalyst for producing chlorine by oxidizing hydrogen chloride with oxygen, wherein the supported ruthenium oxide catalyst is supported on a titanium oxide carrier containing 20% or more of rutile crystalline titanium oxide. 2. The catalyst according to claim 1, wherein the content of rutile crystalline titanium oxide in the titanium oxide is 30% or more. 3. The catalyst according to claim 1, wherein the content of the rutile crystalline titanium oxide in the titanium oxide is 80% or more. 4. The catalyst according to claim 1, wherein the content of rutile crystalline titanium oxide in the titanium oxide is 90% or more. 5. The amount of OH groups per unit weight of the carrier is 0.1%.
The catalyst according to claim 1, wherein titanium oxide containing from × 10 ^-4 to 30 × 10 ^-4 (mol / g-support) is used as the support. 6. The amount of OH groups per unit weight of the carrier is 0.2
The catalyst according to claim 1, wherein titanium oxide containing from × 10 ^{-4 to} 20 × 10 ^-4 (mol / g-support) is used as the support. 7. The amount of OH groups per unit weight of the carrier is 3 × 1
2. The catalyst according to claim 1, wherein titanium oxide containing 0 ^-4 to 10 × 10 ^-4 (mol / g-support) is used as the support. 8. The amount of OH groups per unit weight of the carrier is 3 × 1
4. The catalyst according to claim 3, wherein titanium oxide containing 0 ^-4 to 10 × 10 ^-4 (mol / g-support) is used as the support. 9. The amount of OH groups per unit weight of the carrier is 3 × 1
The catalyst according to claim 4, wherein titanium oxide containing 0 ^-4 to 10 x 10 ^-4 (mol / g-support) is used as the support. 10. The catalyst according to claim 1, which is prepared by a production method comprising the following steps. Ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier Reduction step: a step of reducing the one obtained in the ruthenium compound supporting step with a reductive hydride compound An oxidizing step: a step of oxidizing the one obtained in the reducing step 11. The catalyst according to claim 1, prepared by a production method comprising the following steps. Ruthenium compound supporting step: A step of supporting a ruthenium compound on a catalyst carrier Reducing compound treatment step: A step of treating the one obtained in the ruthenium compound supporting step with a reducing compound Oxidation step: Oxidizing the one obtained in the reducing compound treatment step Process 12. The catalyst according to claim 1, prepared by a production method comprising the following steps. Ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier Alkali treatment step: a step of adding an alkali to the one obtained in the ruthenium compound supporting step Reducing compound processing step: a reducing compound obtained in the ruthenium compound supporting step Oxidation step: Step of oxidizing the substance obtained in the reducing compound treatment step