JP2002292279A - Ruthenium oxide carrying catalyst and method for producing chlorine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ruthenium oxide carrying catalyst which has a high activity, produces chlorine with smaller quantity of catalyst and at lower temperature and is little in the sintering of ruthenium oxide particles on a carrier which are active species during a reaction and, further, to provide a method for producing chlorine which oxidizes hydrogen chloride with oxygen in the presence of the catalyst. SOLUTION: This ruthenium oxide carrying catalyst for producing chloride carries one kind of oxide selected from a group of oxides of Si, Zr, Al and Nb on the carrier surface. Likewise, in this method for producing chloride which is also a method for producing chlorine by oxidizing hydrogen chloride with oxygen, one kind of oxide selected from the group of oxides of Si, Zr, Al and Nb is carried on the carrier surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a supported ruthenium oxide catalyst and a method for producing chlorine. More specifically, the present invention relates to a method for producing chlorine by oxidizing a supported ruthenium oxide catalyst and hydrogen chloride, which is characterized in that it has high activity and can produce chlorine at a lower reaction temperature with a smaller amount of catalyst. Further, the present invention relates to a catalyst which causes less sintering of ruthenium oxide particles on a carrier which is an active species during the reaction, and a method for producing chlorine in which hydrogen chloride is oxidized by oxygen in the presence of the catalyst.

[0002]

2. Description of the Related Art A supported ruthenium oxide catalyst will be described. The 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. Is known to be. For example, JP-A-9-67103 describes that a ruthenium compound supported on titanium oxide can be obtained by hydrolyzing a ruthenium compound with an alkali metal hydroxide, supporting the compound on titanium hydroxide, and calcining with air. ing. We also oxidize the supported metal ruthenium catalyst, oxidize the ruthenium chloride supported on the carrier with air, fix the ruthenium chloride supported on the support, and then treat with hydrazine and oxidize. It has been found that a ruthenium oxide catalyst can be obtained. It is considered that the dispersity of the ruthenium oxide particles supported on the same carrier greatly affects the activity of the catalyst in any of the catalysts.

Under these circumstances, a catalyst in which an acid-resistant sintering-preventing compound is supported on a catalyst has high heat resistance, and the sintering of ruthenium oxide particles on a carrier, which is an active species, is small and high activity. The development of a supported ruthenium oxide catalyst has been desired.

Further, a method for producing chlorine will be described. Chlorine is useful as a raw material for vinyl chloride, phosgene and the like, and is also well known to be obtained by oxidation of hydrogen chloride. For example, Deaco using a Cu-based catalyst
The n reaction is well known. Further, for example, British Patent No. 1,046,313 describes a method of oxidizing hydrogen chloride using a catalyst containing a ruthenium compound, and further, among the ruthenium compounds, particularly, ruthenium (III) chloride Is also stated to be effective. Also described is a method in which a ruthenium compound is supported on a carrier and used, and examples of the carrier include silica gel, alumina, pumice, and ceramic materials. As an example, a ruthenium chloride catalyst supported on silica is mentioned. However, when an experiment was conducted using a catalyst prepared by following the preparation method of the silica-supported ruthenium (III) chloride catalyst described in the patent publication, the ruthenium compound as a catalyst component volatilized violently. Was found to be inconvenient for general use. In addition, for example, EP 0 844 413 A2 describes a method for oxidizing hydrogen chloride using a chromium oxide catalyst. However, the conventionally known method has a problem that the activity of the catalyst is insufficient and a high reaction temperature is required.

[0005] When the activity of the catalyst is low, a higher reaction temperature is required. However, 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-friendly 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. From this point of view, the development of a catalyst having high activity and usable at a low temperature has been desired.

[0006] 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. By using a highly active catalyst and carrying out the reaction at a lower temperature, more favorable reaction conditions can be selected equilibrium. It is also preferable to carry out the reaction at a lower temperature in terms of catalyst stability.

The catalyst used for the oxidation reaction of hydrogen chloride includes various supported ruthenium oxide catalysts.
A catalyst that supports an acid-resistant anti-sintering compound on the catalyst so that the sintering of ruthenium oxide particles on the carrier, which is an active species, is reduced during the reaction, and the activity decreases even when the reaction temperature increases. It has been desired to develop a catalyst having low heat resistance and high heat resistance.

[0008]

The present invention relates to a supported ruthenium oxide catalyst and a method for producing chlorine, characterized in that it has high activity and can produce chlorine at a lower reaction temperature with a smaller amount of catalyst. It is still another object of the present invention to provide a catalyst in which sintering of ruthenium oxide particles on a carrier which is an active species during the reaction is small, and a method for producing chlorine in which hydrogen chloride is oxidized by oxygen in the presence of the catalyst.

[0009]

That is, the first invention of the present invention is a supported ruthenium oxide catalyst,
The present invention relates to a supported ruthenium oxide catalyst which is a catalyst for producing chlorine in which one kind of oxide selected from the group consisting of oxides of i, Zr, Al and Nb is supported on the surface of a carrier. A second aspect of the present invention is a method for producing chlorine by oxidizing hydrogen chloride with oxygen, wherein the catalyst comprises Si, Zr, Al,
The present invention relates to a method for producing chlorine, which is a supported ruthenium oxide catalyst in which one kind of oxide selected from the group of Nb oxides is supported on the surface of a carrier.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Among the present invention, the supported ruthenium oxide catalyst in the first invention is Si, Zr, Al, Nb.
Is a supported ruthenium oxide catalyst which is a catalyst for producing chlorine in which a kind of oxide selected from the group of oxides is supported on the surface of a carrier.

The carrier used in the present invention includes oxides of elements such as titanium oxide, alumina, zirconium oxide, silica, titanium composite oxide, zirconium composite oxide, aluminum composite oxide, silicon composite oxide, and the like. Complex oxides are mentioned, and preferred carriers are titanium oxide, alumina, zirconium oxide and silica, and more preferred carriers are titanium oxide. Titanium oxide is amorphous,
Various crystal forms can be mentioned, and anatase type and rutile type are preferably used. More preferably, rutile crystal form titanium oxide is used.

Si, Zr, Al, N used in the present invention
The supported ruthenium oxide catalyst, which is a catalyst for chlorine production in which one kind of oxide selected from the group of oxides b is supported on the carrier surface, is formed on the surface of the catalyst supporting ruthenium oxide on the carrier. It is a catalyst. Si, Zr, A
An example of a specific method of supporting one kind of oxide selected from the group of oxides of l and Nb on the support surface will be described in the section of the example of the catalyst preparation method below.

An example of a specific method for preparing a catalyst in which ruthenium oxide is supported on the above-mentioned carrier is described in the section of a method for preparing a catalyst below. May be formed.

The weight ratio of ruthenium oxide to the carrier is preferably from 0.1 / 99.9 to 20.0 / 80.0,
More preferably, 0.5 / 99.5 to 15.0 / 85.
0, and still more preferably 1.0 / 99.0-1.
5.0 / 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 supported ruthenium oxide include ruthenium dioxide and ruthenium hydroxide.

The weight ratio of the supported oxides of Si, Zr, Al and Nb to the carrier is preferably 0.1 / 99.9.
０．０20.0 / 80.0, more preferably 0.1
/99.5 to 10.0 / 90.0, and still more preferably 0.1 / 99.0 to 5.0 / 95.0. If the ratio of the supported Si, Zr, Al, and Nb oxides is too high, the activity may decrease, and the supported Si, Z
If the ratio of the oxides of r, Al, and Nb is too low, sintering of the catalyst may not be suppressed.

Preferred specific examples 1 and 2 for preparing the supported ruthenium oxide catalyst according to the present invention will be described. Hereinafter, as more detailed preparation examples, the first to third preparation examples will be described.

As a preferred specific example 1 of preparing the supported ruthenium oxide catalyst in 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 Firing step: The product obtained in the ruthenium compound supporting step is heated at a temperature of 200 ° C. or more in an inert gas, an oxidizing gas, or a reducing gas. Firing step: An alkoxide compound supporting step: a step of supporting an alkoxide compound represented by the following formula (1) on the one obtained in the firing step: MX _n (OR) _m (1) where M = Si, Zr, Al, Nb , X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n is 0 to
4, m is in the range of 1 to 5. Oxide forming step: Step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step

As a more preferred specific example 2 for preparing the supported ruthenium oxide catalyst in 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 Firing step: the product obtained in the ruthenium compound supporting step is heated at a temperature of 200 ° C. or more in an inert gas, an oxidizing gas, or a reducing gas. Baking step washing step: step of washing the one obtained in the baking step with a neutral or alkaline solution alkoxide compound supporting step: supporting the alkoxide compound represented by the following formula (1) on the one obtained in the washing step Step MX _n (OR) _m (1) where M = Si, Zr, Al, Nb, X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n is 0 to 0
4, m is in the range of 1 to 5. Oxide forming step: Step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step

First, a specific example 1 will be described. The ruthenium compound supporting step will be described. As the carrier, the same carrier as the carrier described in the section of the carrier used in the present invention is used.

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
Such as ruthenium nitrosyl complex and ruthenium phosphine complex
Which compounds are mentioned. Preferred ruthenium compounds
As a material, RuCl_Three, RuCl_ThreeLute such as hydrate
Chloride, RuBr_Three, RuBr_ThreeSuch as hydrates
Ruthenium halide compounds such as ruthenium bromide
Can be More preferably, ruthenium chloride hydrate is used.
Can be

Examples of the method for supporting the ruthenium compound on the carrier include an impregnation method and an equilibrium adsorption method.

Next, the firing step will be described. As a method of firing the product obtained in the ruthenium compound-supporting step at a temperature of 200 ° C. or higher in an inert gas, an oxidizing gas or a reducing gas, the inert gas may be an inert gas such as nitrogen or helium. There is a method of firing in an atmosphere. Examples of the oxidizing gas include air, oxygen, and a mixed gas of nitrogen and oxygen. Examples of the reducing gas include hydrogen and a mixed gas of hydrogen and nitrogen.

In this step, the ruthenium compound is supported on the carrier, dried, and then the ruthenium compound is immobilized on the carrier. This is a step for enabling the processing to be performed. Compared with a catalyst that has not been subjected to this step, the next step is performed more stably, and the catalytic activity is dramatically increased. Preferably, a method of firing in an oxidizing gas or a reducing gas is used. More preferably, a method of firing in air or a mixed gas of hydrogen and hydrogen and nitrogen is used.

The firing temperature is preferably 100 to 600 ° C.
And more preferably 200 to 350 ° C. If the firing temperature is too low, the ruthenium compound is eluted in the next step, making it impossible to carry out a stable treatment, and the catalytic activity may be insufficient. On the other hand, if the firing temperature is too high, sintering of the ruthenium compound particles occurs, and the catalytic activity decreases. The firing time is preferably 30 minutes to 10 hours.

When calcined with a reducing gas at a temperature equal to or higher than the reduction temperature of the ruthenium compound supported in the ruthenium compound supporting step, the particles supported on the carrier are converted into metallic ruthenium, and the particles are converted to metal ruthenium at a temperature equal to or higher than the oxidation temperature. When calcined, the particles carried on the carrier are converted to ruthenium oxide. For example, when sintering ruthenium chloride hydrate supported on a carrier, sintering in air is
The ruthenium chloride hydrate is oxidized to ruthenium oxide at a temperature of 50 ° C. or higher, and when calcined in a hydrogen atmosphere, the ruthenium chloride hydrate is reduced at a temperature of 200 ° C. or higher and converted to metal ruthenium.

Next, the step of supporting the alkoxide compound will be described. This step is a step of supporting an alkoxide compound.
An alkoxide compound represented by the following formula (1) is exemplified. MX _n (OR) _m (1) where M = Si, Zr, Al, Nb, X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n is 0 to
4, m is in the range of 1 to 5.

Preferably, Si (OCH ₃ ) ₄ , Si (O
_{C 2 H 5) 4, Si} (OCH 2 CH 2 CH 3) 4, Si [OC
Alkoxides of silicon such as H (CH ₂ CH ₃ ) ₂ ] ₄ , Zr
(OC ₂ H ₅ ) ₄ , Zr (OCH ₂ CH ₂ CH ₃ ) ₄ , Zr
[OCH (CH ₃ ) ₂ ] ₄ , Zr [O (CH ₂ ) ₃ C
_{H 3] 4, Zr [OC} (CH 3) 3] alkoxides of zirconium, such as _{4, Al (OC 2 H 5} ) 3, Al (OCH 2 C
H ₂ CH ₃ ) ₃ , Al [OCH (CH ₃ ) ₂ ] ₃ , Al [O
Examples include aluminum alkoxides such as (CH ₂ ) ₃ CH ₃ ] ₃ and Al [OC (CH ₃ ) ₃ ] _3, and niobium alkoxides such as Nb (OC ₂ H ₅ ) ₅ . Also, SiCl
(OC ₂ H ₅ ) ₃ , SiCl ₂ (OC ₂ H ₅ ) ₂ , SiCl
Alkoxide chloride such as ₃ (OC ₂ H ₅ ), SiCl ₄
A mixed solution of ZrCl ₄ and alcohol, a mixed solution of AlCl ₃ and alcohol, and the like can also be used. More preferred are alkoxides of silicon and alkoxides of zirconium. As a method of supporting on a carrier, it is dissolved in a solvent such as alcohol,
There is a method of impregnation.

The present method can also be carried out when the oxide produced from the alkoxide compound used in this step becomes the same compound as the carrier used after the production of the catalyst.

Next, the oxide forming step will be described.
In this step, an oxide is formed on the surface of the product obtained in the alkoxide compound supporting step. As a method for forming an oxide, firing at a temperature of 200 ° C. or higher in an atmosphere of an inert gas such as nitrogen or helium, or firing in an atmosphere of an oxidizing gas such as air, oxygen, and a mixed gas of nitrogen and oxygen. Method. When a gas containing water is used in this step, the hydrolysis of the alkoxide proceeds simultaneously, which is a preferable method. The water content is preferably 1% to 12% by volume percentage, and more preferably 2% to 10%.

In this step, when the alkoxide compound supported on the catalyst surface is used for the oxidation reaction of hydrogen chloride,
Since the purpose is to form an oxide so that the oxide is not deteriorated by the reaction gas and the product gas, it is necessary to select a method of forming the oxide with the alkoxide compound to be supported. When an alkoxide of silicon or an alkoxide of zirconium is used as the alkoxide compound, a method of firing in air at a temperature of 250 ° C. or higher is preferably used.

Further, in the firing step, when the calcination is performed using an oxidizing gas at a temperature lower than the oxidation temperature of the ruthenium compound, the supported ruthenium compound is a partially oxidized compound. When oxidized using a reductant such as the above and an inert gas, it is present as a supported compound and is not converted to ruthenium oxide, so it is necessary to convert it to ruthenium oxide in this step. As a method of converting a compound partially oxidized in this step, a reductant such as metal ruthenium, or a supported compound to ruthenium oxide, baking with an oxidizing gas can be mentioned, and preferably a temperature of 250 ° C. or more. Firing in air.

In the firing step or the oxide forming step,
The ruthenium compound particles supported on the carrier are converted to a supported ruthenium oxide catalyst. The conversion of the produced particles to ruthenium oxide after catalyst preparation was confirmed by X-ray diffraction and XPS.
(X-ray photoelectron spectroscopy) or the like. After the catalyst is prepared, substantially all of the generated particles are preferably converted to ruthenium oxide. Can be done.

The weight ratio of ruthenium oxide to the carrier is preferably from 0.1 / 99.9 to 20.0 / 80.0,
More preferably, 0.5 / 99.5 to 15.0 / 85.
0, and still more preferably 1.0 / 99.0-1.
5.0 / 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 supported ruthenium oxide include ruthenium dioxide and ruthenium hydroxide.

The weight ratio of the oxide formed from the supported alkoxide compound to the carrier is preferably 0.1 / 9
9.9 to 20.0 / 80.0, more preferably
0.1 / 99.5 to 10.0 / 90.0, and still more preferably 0.1 / 99.0 to 5.0 / 95.0. If the ratio of the oxide generated from the supported alkoxide compound is too high, the activity may be reduced, and if the ratio of the oxide generated from the supported alkoxide compound is too low, the sintering of the catalyst may not be suppressed. .

Next, a more preferred embodiment 2 for preparing a supported ruthenium oxide catalyst according to the present invention will be described. The rest is the same as embodiment 1 except for the washing step.

That is, in the ruthenium compound supporting step, the supporting method and the ruthenium compound described in the section of the preferred embodiment 1 are similarly used.

Next, the firing step is the same as the method described in the preferred embodiment 1.

Next, the cleaning step will be described. Although this step is not an essential step, it is a preferable step because the activity of the catalyst is improved by performing this step. As a method for washing the product obtained in the sintering step, a method of washing with pure water, a neutral or alkaline solution may be mentioned, and as the pure water used, ion-exchanged water, distilled water, neutral As a solution, a solution of an alkali metal halide or the like, a solution of an organic solvent such as an alcohol, or an alkaline solution of an alkali metal hydroxide, carbonate, hydrogen carbonate, and ammonia, ammonium carbonate,
A solution such as a mixed solution of ammonium hydrogen carbonate, a hydroxide of an alkali metal and hydrazine may be used. Preferably, a solution of pure water or an alkali metal hydroxide, carbonate, bicarbonate, or ammonia is used. Water is preferably used as the solvent.

The product obtained in the washing step is usually dried.

For the alkoxide compound supporting step and the oxide forming step, the method described in the section of the first preferred embodiment is similarly used.

As for the weight ratio of ruthenium oxide to the carrier and the weight ratio of the oxide formed from the alkoxide compound to be carried to the carrier, the weight ratio described in the section of the first preferred embodiment is similarly used.

As a more preferred specific example of preparing the supported ruthenium oxide catalyst in the present invention, a preparation method including the following steps can be mentioned. Ruthenium halide supporting step: A step of supporting a ruthenium compound on a catalyst carrier Firing step: The product obtained in the ruthenium compound supporting step is heated at a temperature of 200 ° C. or more in an inert gas, an oxidizing gas, or a reducing gas. Washing step: washing the product obtained in the firing step with a neutral or alkaline solution alkoxide compound supporting step: carrying the alkoxide compound represented by the following formula (1) on the one obtained in the washing step MX _n (OR) _m (1) where M = Si, Zr, Al, Nb, X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n is 0 to
4, m is in the range of 1 to 5. Oxide forming step: Step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step

The ruthenium halide supporting step is a step of supporting the ruthenium halide on the catalyst carrier. Examples of the ruthenium halide supported on the carrier include various ruthenium halides already exemplified, and among them, RuCl ₃ , ruthenium chloride such as RuCl ₃ hydrate, RuBr ₃ , RuBr ₃ hydrate and the like A preferred example is a ruthenium halide such as ruthenium bromide. Preferred ruthenium halides include ruthenium chlorides such as RuCl ₃ and RuCl ₃ hydrate, and ruthenium bromides such as RuBr ₃ and RuBr ₃ hydrate. 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 not dried, but a method of drying is a preferred example.
This drying is an operation for removing the water content of the impregnated ruthenium halide aqueous solution, and is distinguished as an operation having a different meaning from the subsequent firing step.

For the firing step, the washing step, the alkoxide compound supporting step, and the oxide forming step, the same methods as those described in the preferred embodiment 1 are used.

Further, as the supported ruthenium oxide catalyst used in the present invention, a catalyst using a carrier containing rutile crystalline titanium oxide as a carrier can be used.

As the carrier, titanium oxide containing rutile crystal form, composite oxide of titanium oxide containing rutile crystal form, titanium oxide containing rutile crystal form and alumina, zirconium oxide, silica, zirconium composite oxide, aluminum composite oxide And a mixture with a silicon composite oxide. Preferred carriers are titanium oxide containing a rutile crystal form and a mixture of titanium oxide containing a rutile crystal form and alumina.

The titanium oxide containing rutile crystal-based titanium oxide used in the present invention is obtained by measuring the ratio of rutile crystal to anatase crystal in titanium oxide by X-ray diffraction analysis and including rutile crystal. Points to something. Various X-ray sources are used. For example, a Kα ray of copper is used. 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 2θ = 25.3 degrees on the (101) plane. Is determined using the intensity of the diffraction peak. The carrier used in the present invention has a peak intensity of rutile crystal and anatase crystal, or has a peak intensity of rutile crystal. That is, a substance having both the diffraction peak of the rutile crystal and the diffraction peak of the anatase crystal may be used, or a substance having only the diffraction peak of the rutile crystal may be used. Preferably, 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 10% or more.

Specific examples of preparation of the supported ruthenium oxide catalyst in the present invention will be specifically described from the first preparation example to the third preparation example.

First, a first preparation example will be described from Example 1 to Example 4. Examples 1 to 4 are preparation methods comprising the following steps.

Example 1 shows a ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier. A calcining step: the product obtained in the ruthenium compound supporting step was oxidized in an inert gas at a temperature of 200 ° C. or more. Baking step in gas or reducing gas alkoxide compound supporting step: step of supporting an alkoxide compound represented by the following formula (1) on the one obtained in the baking step: MX _n (OR) _m (1) = Si, Zr, Al, Nb, X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n is 0 to
4, m is in the range of 1 to 5. Oxide forming step: a preparation example comprising a step of forming an oxide on the surface of the one obtained in the alkoxide compound supporting step, and the preferred specific example 1 already described.
Is the same as

Example 2 shows a ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier. Baking step in medium or reducing gas washing step: washing the substance obtained in the baking step with a neutral or alkaline solution alkoxide compound supporting step: washing the alkoxide compound represented by the following formula (1) in the washing step MX _n (OR) _m (1) where M = Si, Zr, Al, Nb, X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n is 0 to 0
4, m is in the range of 1 to 5. Oxide forming step: a preparation example comprising a step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step, and the preferred specific example 2 already described.
Is the same as

Example 3 shows a ruthenium compound-supporting step: a step of supporting a ruthenium compound on a catalyst carrier. Step of firing in gas or reducing gas Reduction step: Step of treating the one obtained in the firing step with a reducing agent Alkoxide compound-supporting step: Obtained in the reduction step of an alkoxide compound represented by the following formula (1) MX _n (OR) _m (1) where M = Si, Zr, Al, Nb, X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n is 0 to 0
4, m is in the range of 1 to 5. Oxide forming step: This is a preparation example comprising a step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step.

Example 4 shows a ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier. Step of baking in medium or reducing gas Cleaning step: Step of washing the one obtained in the firing step with a neutral or alkaline solution Reduction step: Step of treating the one obtained in the washing step with a reducing agent Alkoxide compound Supporting step: a step of supporting the alkoxide compound represented by the following formula (1) on the one obtained in the reducing step: MX _n (OR) _m (1) where M = Si, Zr, Al, Nb, X = halogen element , R = a saturated alkyl group having 4 or less carbon atoms, n is 0 to
4, m is in the range of 1 to 5. Oxide forming step: This is a preparation example comprising a step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step.

The ruthenium compound supporting step, firing step, washing step, alkoxide compound supporting step, and oxide forming step in Examples 1 to 4 described above have been described in the preferred specific examples 1 and more preferred specific examples 2. ,
The reduction step will be described below.

That is, although the reduction step is not an essential step, it is a preferable step since the activity of the catalyst may be improved by performing this step. Preferred examples of the reducing agent include a borohydride compound and hydrogen. As a treatment method, the product obtained in the previous process
When treating with a borohydride compound, it is preferable to carry out in a liquid phase. In the case of treatment with hydrogen, treatment in a liquid phase or a gaseous phase is possible, but treatment in a gaseous phase is preferred.

Next, in a second preparation example, Examples 5 to 8 will be described. Examples 5 to 8 are preparation methods comprising the following steps.

Example 5 is as follows: a ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier. Firing step in gas or reducing gas Hydrazine treatment step: Step of treating the one obtained in the firing step with a mixed solution of hydrazine and alkali. MX _n (OR) _m (1) where M = Si, Zr, Al, Nb, X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n Is 0
4, m is in the range of 1 to 5. Oxide forming step: This is a preparation example comprising a step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step.

Example 6 shows a ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier. A calcining step: the product obtained in the ruthenium compound supporting step was subjected to oxidizing gas Step of firing in medium or reducing gas Hydrazine treatment step: Step of treating the one obtained in the firing step with a mixed solution of hydrazine and alkali Alkali metal chloride addition step: Addition of alkali metal chloride to the one obtained in hydrazine treatment Oxidation step: Step of oxidizing the substance obtained in the alkali metal chloride addition step Alkoxide compound supporting step: Step of supporting the alkoxide compound represented by the following formula (1) on the substance obtained in the oxidation step MX _n (OR) _m (1) However, M = Si, Zr, Al , Nb, X = halogen, R = the number of carbon atoms is 4 or less Sum alkyl group, n is 0
4, m is in the range of 1 to 5. Oxide forming step: This is a preparation example comprising a step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step.

Example 7 shows a ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier. A calcining step: the product obtained in the ruthenium compound supporting step was oxidized in an inert gas at a temperature of 200 ° C. or more. Firing in gas or reducing gas Hydrazine reducing step: Reducing the product obtained in the firing step with a mixed solution of hydrazine and alkali Alkoxide compound-supporting step: Hydrazine converting alkoxide compound represented by the following formula (1) MX _n (OR) _m (1) where M = Si, Zr, Al, Nb, X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n Is 0
4, m is in the range of 1 to 5. Oxide forming step: This is a preparation example comprising a step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step.

Example 8 shows a ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier. Firing in medium or in reducing gas Hydrazine reducing step: Processing the product obtained in the firing step with a mixed solution of hydrazine and alkali Alkali metal chloride addition step: Alkali metal chloride Oxidation step: Step of oxidizing the substance obtained in the alkali metal chloride addition step Alkoxide compound supporting step: Step of supporting the alkoxide compound represented by the following formula (1) on the substance obtained in the oxidation step MX _n (OR) _m (1) However, M = Si, Zr, Al , Nb, X = halogen, R = the number of carbon atoms is 4 or less Sum alkyl group, n is 0
4, m is in the range of 1 to 5. Oxide forming step: This is a preparation example comprising a step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step.

In the above Examples 5 to 8, the ruthenium compound supporting step, the calcination step, the alkoxide compound supporting step, and the oxide forming step are preferably the specific examples 1.
As described in the second embodiment, the hydrazine treatment step, the hydrazine reduction step, the alkali metal chloride addition step, and the oxidation step will be described below.

The hydrazine treatment step is a step of treating the product obtained in the firing step with a mixed solution of hydrazine and alkali. As a method of treating with a mixed solution of hydrazine and alkali, impregnating with a mixed solution of hydrazine and alkali,
There is a method such as immersion in a mixed solution of hydrazine and alkali. The concentration of hydrazine used in the hydrazine treatment step is preferably 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 water or alcohol. Preferably, an aqueous hydrazine 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 20 times the mole of ruthenium halide. 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, but preferably 0.1 to 20 times the equivalent of the ruthenium halide is used. You. The concentration of the alkali varies depending on the alkali used, but is preferably 0.1 to 10 mol / l. The immersion time in the solution of hydrazine and alkali is preferably 5 minutes to 5 minutes.
I have time. The temperature range is preferably from 0 to 50
C., but more preferably 10 to 50.degree. After immersion in a solution of hydrazine and alkali, the treated solid is preferably filtered off from the solution.

The hydrazine reduction step is the same operation as the hydrazine treatment step, except that the supported ruthenium is reduced to zero valence. The difference from the hydrazine treatment step is the reduction temperature.
Whereas the hydrazine reduction step is preferably performed at 50 ° C. or higher, more preferably 5 ° C.
0 to 100 ° C.

As a more preferred method, the one produced in the hydrazine treatment step or the hydrazine reduction step is washed to remove 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 preferable method is a method in which the catalyst produced in the hydrazine treatment step or the hydrazine reduction 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 alkali metal chloride addition step is a step of adding an alkali metal chloride to the product obtained in the hydrazine treatment step or the hydrazine 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, and in this case, it is preferable to convert the catalyst into a highly active supported ruthenium oxide by oxidizing the hydrazine-treated or hydrazine-reduced catalyst in the presence of an alkali metal salt. It is.

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

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

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

The purpose of the 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. The range of the drying conditions is preferably 50 to
200 ° C., preferably for 1 to 10 hours.

The oxidation step is a step of oxidizing the substance obtained in the hydrazine treatment step or the hydrazine reduction 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 used. It is a preferable preparation example to oxidize to a highly active supported ruthenium oxide by calcining a hydrazine-treated or hydrazine-reduced product in the presence of an alkali metal salt in a gas containing oxygen. The gas containing oxygen usually includes air.

The range of the firing temperature is preferably from 100 to 6
It is 00 ° C, more preferably 280-450 ° C. If the firing temperature is too low, many particles generated by hydrazine treatment or hydrazine reduction remain as ruthenium oxide precursors, and the catalytic activity may be insufficient.
On the other hand, if the firing temperature is too high, agglomeration of ruthenium oxide particles occurs, and the catalytic activity decreases. The firing time is preferably 30 minutes to 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 hydrazine treatment or hydrazine reduction carried on the carrier are converted to a supported ruthenium oxide catalyst. The conversion of particles produced by hydrazine treatment or hydrazine reduction to ruthenium oxide is confirmed by X-ray diffraction and XPS (X-ray photoelectron spectroscopy).
It can be confirmed by such an analysis. In addition, particles generated by hydrazine treatment or hydrazine reduction,
It is preferable that substantially the entire amount thereof is converted to ruthenium oxide, but particles produced by hydrazine treatment or hydrazine reduction may be allowed to remain as long as the effects of the present invention are not impaired.

A preferable preparation method is to subject the hydrazine-treated or hydrazine-reduced product to an oxidation treatment, 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 alkali metal chloride after washing, there is a method of adding an aqueous solution of silver nitrate to a 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. The range of drying conditions is preferably 5
It is 0-200 degreeC, Preferably it is 1-10 hours.

Next, Example 9 will be described in the third preparation example.
Example 9 is a preparation method comprising the following steps. Example 9 is a ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier. A drying step: a step of drying the product obtained in the ruthenium compound supporting step at a temperature from room temperature to 200 ° C. a reduction step: Step of reducing ruthenium with the obtained one using a reducing agent Alkoxide compound supporting step: Step of supporting an alkoxide compound represented by the following formula (1) on the one obtained in the reducing step: MX _n (OR) _m (1 However, M = Si, Zr, Al, Nb, X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n is 0 to
4, m is in the range of 1 to 5. Oxide forming step: This is a preparation example comprising a step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step.

The ruthenium compound supporting step, the alkoxide compound supporting step, and the oxide forming step in the above Example 9 have been described in the preferred specific example 1 and the more preferred specific example 2. The reduction step is the same as the reduction step described in the first preparation example, but will be described below.

[0081] After drying the ruthenium compound supported on the carrier, but are exemplified as a preferred method a method of reducing the liquid phase, as the reducing agent, hydrogen, 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
Borohydride compounds such as H ₆ , K ₃ B ₄ H ₁₀ , K ₂ B ₅ H ₉ , and Al (BH ₄ ) ₃ ; 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
And organic aluminum compounds such as HCH ₂ ] ₂ AlH, organic lithium compounds, organic sodium compounds, organic potassium compounds, and organic magnesium compounds.

When hydrogen is used as the reducing agent, a method of reducing in the gas phase is more preferable.
The reduction temperature is preferably from 150 ° C to 400 ° C,
~ 380 ° C is more preferred.

The supported ruthenium oxide catalyst produced by the above steps was highly active, and more active than the catalyst prepared by oxidizing ruthenium chloride with air. Further, after the ruthenium chloride was immobilized, the catalyst was subjected to hydrazine treatment, and the activity was higher than that of the oxidation-treated catalyst.

The change of the ruthenium oxide particles before and after the reaction of the produced supported ruthenium oxide catalyst can be observed by the measurement of X-ray absorption fine structure analysis (XAFS).

Here, the measurement of general X-ray absorption fine structure analysis (XAFS) will be described.
X-ray absorption fine structure Yasuo Udagawa (ed., 1993) ".

When a substance is placed on the X-ray beam line, the intensity of the X-ray (incident X-ray: I0) irradiated on the substance and the intensity of the X-ray transmitted through the substance (transmitted X-ray: It) are calculated as follows.
The X-ray absorbance of the substance is calculated. When the X-ray absorption spectrum is measured while changing the X-ray energy while monitoring the increase and decrease of the X-ray absorbance, a sharp rise (absorption edge) of the X-ray absorbance is observed at a certain energy position. X
In the line absorption spectrum, 30 to 10
A fine vibration structure appearing in a region on the high energy side of about 00 eV is called a wide area X-ray absorption fine structure (EXAFS). Such a variation in the absorption probability of the X-rays of the absorbing atoms is caused as a result of the interference effect between the photoelectron waves emitted from the absorbing atoms due to the absorption of the X-rays and the photoelectron waves which are scattered and returned by the surrounding atoms. Therefore, by analyzing this in detail, information on the local structure near the absorbed atoms can be obtained.

EXA extracted from X-ray absorption spectrum
When the Fourier transform is applied to the FS spectrum in an appropriate region,
A radial distribution function centered on the X-ray absorbing atoms is obtained. By examining this radial distribution function in detail, from the position of the maximum value of this function, the distance between the absorbing atom and the scattering atom,
From the intensity, information on the number of scattered atoms can be obtained, and structural information near the absorption atom of interest can be clarified.

Using the above measurement method, the change in the particle size of ruthenium oxide on the catalyst can be observed. That is, a is a catalyst used for the reaction, and the catalyst a before and after the reaction is measured by X-ray absorption fine structure analysis (XAFS). For example, at this time, a wide area X-ray absorption fine structure (EXAFS) at the RuK absorption edge obtained from an X-ray absorption spectrum
In the radial distribution function obtained by Fourier transform of the spectrum, the peak intensity of the spectrum corresponding to the number of the second closest ruthenium atoms of the ruthenium atoms in the ruthenium dioxide obtained from the peak intensity near 0.32 nm is determined as a molecule, The peak intensity in the case of ruthenium dioxide having a diameter of 10 nm or more is used as the denominator, and the peak intensity ratios A (a), B
Assuming that (a) is obtained, when A (a) and B (a) are determined as follows, B (a) / A (a) is calculated as Ru in the catalyst.
It can be used as an index of sintering of O ₂ . A (a): peak intensity ratio of the produced catalyst a obtained by the EXAFS method. B (a): The peak intensity ratio determined by the EXAFS method for catalyst a taken out of the produced catalyst after a reaction test for 50 hours shown below.

The ratio of these peak intensity ratios B (a) /
As A (a) approaches 1, it means that the sintering of the ruthenium oxide particles is suppressed, and as it increases from 1, the sintering occurs. However, since the value of A (a) does not change for ruthenium oxide having too large particles, the value of A (a) applicable to this measurement method is A (a) ≦ 0.8,
A catalyst having a higher value of A (a) has lower activity and cannot be said to be suitable for this reaction.

Here, 5 described in the description of B (a)
The method of the 0 hour reaction test will be described. That is,
A reaction tube is filled with 1.5 to 1.5 ml of the supported ruthenium oxide catalyst a. At this time, since the catalytic reaction generates heat, it is preferable to mix and fill with a diluent inert to the reaction. Preferably, the diluent is an α-alumina ball.
Next, under normal pressure, hydrogen chloride gas
77-0.094 mol / ml-cat · h,
The water vapor is adjusted to 0.058 to 0.071 mol / ml-cat.
h and circulate chlorine gas from 0.058 to 0.071 mol /
ml-cat · h and at the same time, oxygen gas at 0.0
68-0.083 mol / ml-cat · h,
While maintaining the hot spot of catalyst a at 380 ± 2 ° C, 5
The reaction is performed for 0 hours.

The Si, Zr, Al, N used in the present invention
The supported ruthenium oxide catalyst in which one kind of oxide selected from the group of oxides b is supported on the carrier surface has less sintering of the ruthenium oxide particles after reacting than the catalyst not supporting the oxide on the carrier surface, and B A catalyst having a small value of (a) / A (a) and suppressing sintering was prepared. The catalyst preferably has a B (a) / A (a) value of 2.0 or less, more preferably 1.5 or less. More preferably, those having 1.3 or less are mentioned.

The second invention of the present invention is a method for producing chlorine using the supported ruthenium oxide catalyst according to the first invention. The description of the catalyst is the same as the description of the supported ruthenium oxide catalyst in the first invention of the present invention.

According to the present invention, chlorine is obtained by oxidizing hydrogen chloride with oxygen using the above catalyst. 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, so that it is desirable to carry out the reaction at a lower temperature, preferably 100 to 500 ° C, more preferably 200 to 380 ° C. Can be 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. However, it is not preferable because other components are simultaneously released when the inert nitrogen gas is released outside the apparatus. Pure oxygen containing no active gas can be used. 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 10 to 20,000 in terms of the ratio GHSV to the feed rate of the raw material hydrogen chloride under atmospheric pressure in the case of the fixed bed gas phase flow system.
h ^-1 .

[0095]

EXAMPLES 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, 44.7 g of pure water and titanium oxide sol (CSB of Sakai Chemical Co., 38% by mass of TiO ₂ content) were added to 60.0 g of titanium oxide powder (Sakai Chemical Co., STR-60R, 100% rutile crystal system). .9
g was added and kneaded. This mixture was extruded into a 1.5 mmφ noodle shape. Next, it was dried in air at 60 ° C. for 2 hours to obtain 57.2 g of white noodle-like titanium oxide. The solid obtained is heated in air from room temperature to 700 ° C. for 2 hours.
The temperature was raised over a period of time and calcined at the same temperature for 3 hours to obtain 55.8 g of white noodle-like titanium oxide. After the firing, the noodle-like solid was trimmed to a length of about 5 mm to obtain a white extruded titanium oxide carrier. Then, the carrier 21.
0 g of commercially available ruthenium chloride (RuCl ₃ .nH ₂ O, R
(u content: 38.2 mass%) An aqueous solution prepared by dissolving in 1.67 g and 11.0 g of pure water was impregnated, and allowed to stand at room temperature overnight. The still thing was dried at 60 degreeC for 2 hours. Then
The obtained solid (22.5 g) was filled in a quartz tube, and hydrogen was passed through the tube furnace at a flow rate of 10 ml / min.
The temperature was raised to 0.2 ° C. in 0.2 hours and calcined at the same temperature for 1 hour to obtain 21.6 g of ruthenium metal supporting titanium oxide. From the calcined product, 7.2 g was fractionated, and 0.11 g of commercially available orthoethyl silicate and 2.8 ethanol were obtained.
g of solution and air-dried at room temperature in air. The obtained solid was dried at 60 ° C. for 2 hours, and then heated in air from room temperature to 300 ° C. in 0.8 hours.
Calcination was performed for 7.3 g to obtain 7.3 g of a black extruded titanium oxide-supported silicon oxide-ruthenium oxide catalyst. The calculated value of the content of ruthenium oxide is calculated as follows: RuO ₂ / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 =
It was 3.8% by mass. The calculated value of the ruthenium content is Ru / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 = 2.
It was 9% by mass. Also, the calculated value of the silicon oxide content is SiO ₂ / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 =
It was 0.43% by mass.

1 g of the thus-obtained titanium oxide-supported silicon oxide-ruthenium oxide catalyst was added to a commercially available α-alumina carrier having a diameter of 2 mm (manufactured by Nikkato Corporation, SSA995).
The catalyst was diluted by thoroughly mixing with 20 g, and charged into a quartz reaction tube (inner diameter: 12 mm).
Oxygen gas was supplied at normal pressure of 2 ml / min and 192 ml / min (both at 0 ° C. and 1 atm). Heat the quartz reaction tube in an electric furnace, and raise the internal temperature (hot spot) to 300 ° C.
It was. At 2.0 hours after the start of the reaction, sampling was performed by flowing the gas at the outlet of the reaction tube through a 30% by mass aqueous solution of potassium iodide, and the amount of chlorine produced and the unreacted amount were determined by an iodine titration method and a neutralization titration method, respectively. The amount of hydrogen chloride was measured. The chlorine production activity per unit catalyst mass determined by the following formula was 8.6 × 10 ⁻⁴ mol / min · g-catalyst. Chlorine formation activity per unit catalyst mass (mol / min · g
−catalyst) = amount of outlet chlorine produced per unit time (mol / m
in) / catalyst weight (g)

Next, a reaction test was performed for 50 hours. That is, 1.25 ml of the obtained titanium oxide-supported silicon oxide-ruthenium oxide catalyst (catalyst a) was thoroughly mixed with 11 g of a 1.7 mmφ titanium oxide-α-alumina extruded product (molded product having an average particle length of 5 mm). The catalyst was diluted and charged into a quartz reaction tube (inner diameter: 18 mm), and hydrogen chloride gas was supplied at a pressure of 0.077 to 0.09 per hour under normal pressure.
4 mol / ml-cat · h is circulated, and water vapor is 0.0
58-0.071 mol / ml-cat · h,
0.058-0.071 mol / ml-cat of chlorine gas
-Circulate the oxygen gas at the same time as 0.068-0.08
The reaction was carried out for 50 hours while maintaining the hot spot of the catalyst a at 380 ± 2 ° C. by flowing 3 mol / ml-cat · h. After performing the reaction for 50 hours, the catalyst was extracted, and the wide area X-ray absorption fine structure (EXAFS) of the RuO ₂ particles of the catalyst before and after the reaction was measured.

EXAFS Measurement Method The RuA absorption edge EXAFS of the catalyst a was measured with an XAFS measurement device at the beam line 10B (BL-10B) of the Synchrotron Radiation Experimental Facility at the Institute of Materials Structure Science, High Energy Accelerator Research Organization. Using a Si (311) channel cut spectral crystal, the incident X-ray intensity (I0) is a 17 cm ion chamber using Ar as a gas, and the transmitted light intensity (It) is
Using a 31 cm ion chamber using Kr,
It was measured at room temperature. In this case, the setting of the measurement area, the interval between immediate fixed points, and the integration time per one measurement point is as follows.

The energy (E) of the incident X-ray is 21590 e
The section from V to 22040 eV is integrated for each point for one second at intervals of 6.43 eV (the number of measurement points is 70). The energy (E) of the incident X-ray is from 22040 eV to 221
In the section up to 90 eV, each point is integrated for 1 second at intervals of 1 eV (the number of measurement points is 150). The energy (E) of the incident X-ray is 225 from 22190 eV.
The section up to 90 eV is integrated for each point for 2 seconds at 2.5 eV intervals (the number of measurement points is 160 points). The energy (E) of the incident X-ray is from 22590 eV to 231.
In the section up to 90 eV, each point is integrated for 2 seconds at intervals of 6 eV (the number of measurement points is 101). The energy was calibrated using the structure near the X-ray absorption edge of the K absorption edge of metallic copper (XANES: X-
ray Absorption Near-Edge
At the position of the energy value (8980.3 eV) of the pre-edge peak appearing in the (Structure) spectrum, the angle of the dispersive crystal was set to 24.934 degrees.

EXAFS analysis method The energy E0 at the absorption edge of the catalyst a was set to 22123 eV, which is the same as the K absorption edge energy E0 of ruthenium dioxide. E0 is an energy value at which the first-order differential coefficient becomes maximum in the spectrum near the X-ray absorption edge. The absorption coefficient in the energy region lower than the absorption edge is Vi
The background determined by applying the equation of ctoreen (Aλ ³ −Bλ ⁴ + C; λ is the wavelength of the incident X-ray and A, B, and C are arbitrary constants) by the least square method is subtracted, and subsequently, the weighted CubicSpline method is used. The absorbance of the isolated atoms was estimated, and the EXAFS function χ (k) was extracted.
Here, k is a wave number of photoelectrons defined by 5.123 × (E−E0) ^1/2 , and the unit of k at this time is nm ⁻¹ . Finally, EXAFS function k ³ χ weighted by the k ³
The (k), k is called for radial distribution function with the Fourier transform in the range of 159 nm ^-1 from 27 nm ^-1. The windowing function of the Fourier transform is a Hanning function, and the window width is 0.1.
5 nm ^-1 was used.

As ruthenium dioxide having a particle diameter of 10 nm or more, NE Chemcat (RuO ₂ : average particle diameter: 25.9 nm) was used.
A radial distribution function of XAFS was determined (FIG. 1). The peak around 0.32 nm of the radial distribution function shown in FIG.
The peak intensity ratio A (a) was determined by using the intensity of the catalyst a as a numerator and the peak intensity of ruthenium dioxide having a particle diameter of 10 nm or more as a denominator, to obtain a value of 0.44.
Similarly, the peak intensity ratio B (a) of the catalyst after the reaction of the catalyst a for 50 hours was determined, and a value of 0.43 was obtained.
The ratio B (a) / A (a) of these peak intensity ratios was 1.0.

Example 2 A catalyst was prepared by the following method. That is, the titanium oxide-supported metal ruthenium 2 obtained after the firing step of Example 1 was used.
From 1.6 g, 7.2 g was fractionated, and commercially available 70% by mass of zirconium propoxide (1-propanol solution) was added.
A solution consisting of 11 g and 2.9 g of ethanol was impregnated and air-dried in air at room temperature. The resulting solid is dried at 60 ° C. for 2 hours, then in air from room temperature to 300 ° C. for 0.8 hours.
The temperature was raised over a period of time and calcined at the same temperature for 3 hours to obtain 7.3 g of a black extruded titanium oxide-supported zirconium oxide-ruthenium oxide catalyst. The calculated value of the content of ruthenium oxide is calculated as follows: RuO ₂ / (RuO ₂ + ZrO ₂ + TiO ₂ ) × 100 =
It was 3.8% by mass. The calculated value of the ruthenium content is Ru / (RuO ₂ + ZrO ₂ + TiO ₂ ) × 100 = 2.
It was 9% by mass. The calculated value of the zirconium oxide content is ZrO ₂ / (RuO ₂ + ZrO ₂ + TiO ₂ ) × 100 =
0.93% by mass.

1 g of the thus-obtained zirconium oxide-ruthenium oxide catalyst supporting titanium oxide was placed on a commercially available α-alumina carrier having a diameter of 2 mm (manufactured by Nikkato Co., Ltd., SSA9
95) The reaction was carried out in accordance with the reaction method of Example 1 except that the catalyst was diluted by thoroughly mixing with 20 g, filled in a quartz reaction tube (inner diameter: 12 mm), and the internal temperature (hot spot) was set to 299 ° C. Was. 2.0 hours after the start of the reaction, the activity of forming chlorine per unit mass of the catalyst was 6.5 × 10 ⁻⁴ mo.
1 / min · g-catalyst.

Next, a reaction test was performed for 50 hours. That is, 1.25 ml of the obtained titanium oxide-supported zirconium oxide-ruthenium oxide catalyst (catalyst a) was 1.7 mm in size.
The catalyst was diluted by thoroughly mixing with 11 g of a titanium oxide-α-alumina extruded molded article having a diameter of 5 mm (average particle length of the molded article was 5 mm), and charged into a quartz reaction tube (18 mm in inner diameter). The reaction was performed according to the procedure. After performing the reaction for 50 hours, the catalyst was withdrawn, and the Ru of the catalyst before and after the reaction was measured.
For the O ₂ particles, a wide area X was measured in accordance with the measurement method of Example 1.
The line absorption fine structure (EXAFS) was measured. The peak around 0.32 nm of the radial distribution function shown in FIG.
The peak intensity ratio A (a) was determined using the intensity of the catalyst a as a numerator and the peak intensity of ruthenium dioxide having a particle size of 10 nm or more as a denominator, to obtain a value of 0.37.
Similarly, the peak intensity ratio B (a) of the catalyst a after 50 hours of the reaction of the catalyst a was determined, and a value of 0.40 was obtained.
The ratio B (a) / A (a) of these peak intensity ratios was 1.1.

Example 3 A catalyst was prepared by the following method. That is, 43.9 g of pure water and titanium oxide sol (CSB of Sakai Chemical Co., 38% by mass of TiO ₂ ) were added to 60.0 g of titanium oxide powder (STR-60R, 100% rutile crystal system) 7 .9
g was added and kneaded. This mixture was extruded into a 1.5 mmφ noodle shape. Next, it was dried in air at 60 ° C. for 2 hours to obtain 50.5 g of white noodle-like titanium oxide. The solid obtained is heated in air from room temperature to 700 ° C. for 2 hours.
The temperature was raised over a period of time and calcined at the same temperature for 3 hours to obtain 49.5 g of white noodle-like titanium oxide. After the firing, the noodle-like solid was trimmed to a length of about 5 mm to obtain a white extruded titanium oxide carrier. Then, the carrier 40.
0 g of commercially available ruthenium chloride (RuCl ₃ .nH ₂ O, R
(u content: 38.2% by mass) was impregnated with an aqueous solution prepared by dissolving in 4.82 g and 20.1 g of pure water, and allowed to stand at room temperature overnight. The still thing was dried at 60 degreeC for 2 hours. Then
44.8 g of the obtained solid was heated from room temperature to 250 ° C. in an air atmosphere for 1.3 hours, and calcined at the same temperature for 2 hours.
2.3 g of ruthenium oxide supporting titanium oxide was obtained. From the calcined product, 8.5 g was collected, 500 ml of pure water was added, washed for 30 minutes, and filtered. Perform this operation 8
I repeated it. The obtained solid was dried at 60 ° C. for 2 hours to obtain 8.5 g of a black solid. Next, the black solid was impregnated with a solution consisting of 0.13 g of commercially available orthoethyl silicate and 4.1 g of ethanol, and air-dried at room temperature in the air. The obtained solid was dried at 60 ° C. for 2 hours, then heated from room temperature to 300 ° C. in air for 0.8 hours, and calcined at the same temperature for 3 hours to obtain 8.5 g of an extruded black titanium oxide-supported oxide. A silicon-ruthenium oxide catalyst was obtained. The calculated value of the content of ruthenium oxide is calculated as follows: RuO ₂ / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 =
It was 5.7% by mass. The calculated value of the ruthenium content is: Ru / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 = 4.
It was 3% by mass. Also, the calculated value of the silicon oxide content is SiO ₂ / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 =
It was 0.44% by mass.

1 g of the titanium oxide-supported silicon oxide-ruthenium oxide catalyst thus obtained was placed on a commercially available α-alumina carrier having a diameter of 2 mm (manufactured by Nikkato Corporation, SSA995).
The reaction was carried out in accordance with the reaction method of Example 1 except that the catalyst was diluted by thoroughly mixing with 20 g, filled in a quartz reaction tube (inner diameter: 12 mm), and the internal temperature (hot spot) was set to 299 ° C. Was. 2.0 hours after the start of the reaction, the activity of forming chlorine per unit mass of the catalyst was 29.5 × 10 ^-4 m.
ol / min · g-catalyst.

Example 4 A catalyst was prepared by the following method. That is, the titanium oxide-supported ruthenium oxide 4 obtained after the firing step of Example 3 was used.
8.5 g of 2.3 g was collected, 500 ml of aqueous ammonia adjusted to 1.8 mass% was added, washed for 30 minutes, and filtered. This operation was repeated three times. Then, 500 ml of pure water was added to the obtained solid, washed for 30 minutes, and filtered. This operation was repeated six times. At this time, the pH of the first cleaning solution was 10.5, and the pH of the sixth cleaning solution was 8.3. The solid obtained is 60
Drying at 2 ° C. for 2 hours gave 8.4 g of a black solid. Next, this black solid was impregnated with a solution containing 0.14 g of commercially available orthoethyl silicate and 4.0 g of ethanol, and air-dried at room temperature in the air. The obtained solid was dried at 60 ° C. for 2 hours, then heated in the air from room temperature to 300 ° C. for 0.8 hours, and calcined at the same temperature for 3 hours, and 8.4 g of a black extruded titanium oxide-supported oxide was oxidized. A silicon-ruthenium oxide catalyst was obtained. The calculated value of the content of ruthenium oxide is calculated as follows: RuO ₂ / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 =
It was 5.7% by mass. The calculated value of the ruthenium content is: Ru / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 = 4.
It was 3% by mass. Also, the calculated value of the silicon oxide content is SiO ₂ / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 =
It was 0.46% by mass.

1 g of the thus-obtained titanium oxide-supported silicon oxide-ruthenium oxide catalyst was added to a commercially available α-alumina carrier having a diameter of 2 mm (manufactured by Nikkato Corporation, SSA995).
The catalyst was diluted by thoroughly mixing with 20 g, and charged into a quartz reaction tube (12 mm inner diameter). 2.0 hours after the start of the reaction, the activity of forming chlorine per unit mass of the catalyst was 28.3 × 10 ⁻⁴ m.
ol / min · g-catalyst.

Example 5 A catalyst was prepared by the following method. That is, 50.0 g of titanium oxide powder (STR-60R, 100% rutile crystal system, Sakai Chemical Co., Ltd.), 1.3 g of organic binder (Shin-Etsu Chemical, Metrosh, 65SH4000) and pure water 3
5.4g and titanium oxide sol (Sakai Chemical Co., Ltd. CSB, TiO
₂ content 38% by mass) was placed in each of two containers, and the mixture was placed in a non-babbling kneader (NBK-1 manufactured by Nippon Seiki Seisakusho Co., Ltd.) at 2000 r.p.m. p. m.
Kneaded for 2 minutes. After kneading the mixture by hand, 3mm
It was extruded into a noodle shape of φ. Then in air, 6
Dried at 0 ° C. for 2 hours, white noodle-like titanium oxide 5
1.4 g were obtained. The resulting solid is air-dried at room temperature to 7
The temperature was raised to 00 ° C in 2 hours, and calcined at the same temperature for 3 hours.
9.2 g of white noodle-like titanium oxide was obtained. After firing,
A white extruded titanium oxide support was obtained by trimming the noodle-like solid to a length of about 5 mm. Next, 6.45 g of this carrier was fractionated, and commercially available ruthenium chloride (R
uCl ₃ .nH ₂ O, Ru content 40.7% by mass) 0.48
An aqueous solution prepared by dissolving 7 g in 3.4 g of pure water was impregnated and allowed to stand at room temperature overnight. The still thing was dried at 60 degreeC for 2 hours. Next, 6.77 g of the obtained solid was heated from room temperature to 250 ° C. in an air atmosphere for 1.3 hours, and calcined at the same temperature for 2 hours to obtain 6.55 g of ruthenium oxide supporting titanium oxide. To the fired product, 300 ml of pure water was added, washed for 30 minutes, and then filtered. This operation 7
I repeated it. The obtained solid was dried at 60 ° C. for 2 hours to obtain 6.6 g of a black solid. Next, this black solid was impregnated with a solution composed of 0.415 g of commercially available orthoethyl silicate and 2.55 g of ethanol, and air-dried at room temperature in the air. The obtained solid was dried at 60 ° C. for 2 hours, then heated in air from room temperature to 400 ° C. for 1.0 hour, and calcined at the same temperature for 3 hours to oxidize 6.65 g of a black extruded titanium oxide-supported oxide. A silicon-ruthenium oxide catalyst was obtained.
The calculated value of the content of ruthenium oxide is calculated as follows: RuO ₂ / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 =
It was 3.8% by mass. The calculated value of the ruthenium content is Ru / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 = 2.
It was 9% by mass. Also, the calculated value of the silicon oxide content is SiO ₂ / (RuO ₂ + SiO ₂ + TiO ₂ ) × 100 =
1.76% by mass.

1.0 g of the thus-obtained titanium oxide-supported silicon oxide-ruthenium oxide catalyst was placed on a commercially available α-alumina carrier having a diameter of 2 mm (manufactured by Nikkato Co., Ltd., SSA99).
5) The reaction was carried out according to the reaction method of Example 1 except that the catalyst was diluted by thoroughly mixing with 30 g, filled in a quartz reaction tube (inner diameter: 12 mm), and the internal temperature (hot spot) was set to 300 ° C. Was done. 2.0 hours after the start of the reaction, the chlorine generation activity per unit catalyst mass was 20.7 × 1
It was 0 ^-4 mol / min · g-catalyst.

Next, a reaction test at 380 ° C. was performed. That is, 2 g of the obtained titanium oxide-supported silicon oxide-ruthenium oxide catalyst was filled in a quartz reaction tube (inner diameter: 18 mm), and hydrogen chloride gas was added at a pressure of 0.01 hour under normal pressure.
3 to 0.018 mol / g-cat.h, water at 0.04
2 to 0.045 mol / g-cat · h, and chlorine gas at a concentration of 0.
042-0.045 mol / g-cat.h, oxygen gas at 0.030-0.031 mol / g-cat.h, and keeping the hot spot of the catalyst at 380 ± 2 ° C. for 50 hours, 122 hours, and 155 hours. The reaction was performed for 0.5 hours. After 50 hours, 122 hours, and 155.5 hours, the catalyst was extracted, and the catalyst activity was measured.

1 g of the catalyst was added to a commercially available α-alumina of 2 mm sphere.
20g carrier (Nikkato Co., Ltd., SSA995)
The catalyst is diluted by mixing and the quartz reaction tube (inner diameter
12mm) and the internal temperature (hot spot) is 300
The reaction was carried out according to the reaction method of Example 1 except that
Was. 2.0 hours after the start of the reaction, the
After 50 hours, 122 hours, and 1 hour.
8.95 × 1 for each of the catalysts after 55.5 hours
0^-Fourmol / min · g-catalyst, 8.2 × 10 ^-Fourmol
/ Min · g-catalyst, 8.1 × 10^-Fourmol / min.
g-catalyst.

Comparative Example 1 A catalyst was prepared by the following method. That is, the titanium oxide-supported metal ruthenium 2 obtained after the firing step of Example 1 was used.
From 1.6 g, 7.2 g was fractionated, then heated in air from room temperature to 300 ° C. for 0.8 hours, calcined at the same temperature for 3 hours, and loaded with 7.4 g of black extruded titanium oxide. A ruthenium oxide catalyst was obtained. The calculated value of the content of ruthenium oxide was RuO ₂ / (RuO ₂ + TiO ₂ ) × 100 = 3.8% by mass. The calculated value of the ruthenium content was Ru / (RuO ₂ + TiO ₂ ) × 100 = 2.9% by mass.

The catalyst was diluted by mixing 1 g of the thus-obtained ruthenium oxide catalyst supported on titanium oxide with 20 g of a commercially available α-alumina carrier (manufactured by Nikkato Co., Ltd., SSA995) of 2 mm spheres to dilute the catalyst. A reaction tube (inner diameter: 12 mm) was filled, and the internal temperature (hot spot) was reduced to 299.
The reaction was performed according to the reaction method of Example 1 except that the temperature was changed to ° C.
2.0 hours after the start of the reaction, the activity of forming chlorine per unit mass of the catalyst was 9.3 × 10 ⁻⁴ mol / min · g-catalyst.

Next, a reaction test was performed for 50 hours. That is, 1.25 ml of the obtained titanium oxide-supported ruthenium oxide catalyst (catalyst a) was added to a 1.7 mmφ titanium oxide catalyst.
α-alumina extrusion molded product (molded product average particle length 5 mm)
The catalyst was diluted by well mixing with 11 g, filled in a quartz reaction tube (18 mm in inner diameter), and reacted according to the reaction method of Example 1. After performing the reaction for 50 hours, the catalyst was extracted, and the wide area X-ray absorption fine structure (EXAFS) was measured for the RuO ₂ particles of the catalyst before and after the reaction in accordance with the measurement method of Example 1. With respect to the peak around 0.32 nm of the radial distribution function shown in FIG.
When (a) was determined, a value of 0.37 was obtained. Similarly, the peak intensity ratio B (a) of the catalyst a after 50 hours of the reaction of the catalyst a was determined, and a value of 0.84 was obtained. The ratio B (a) / A (a) of these peak intensity ratios was 2.3.

Comparative Example 2 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% by weight) was dissolved in 4.0 g of pure water.
After well stirring the aqueous solution, it was adjusted to 12 to 18.5 mesh, and added dropwise to 5.0 g of silica (Carrieract G-10 manufactured by Fuji Silysia K.K.) dried in air at 500 ° C. for 1 hour. Was impregnated. The supported product was cooled to room temperature under nitrogen flow of 100 ml / min.
After heating to 0 ° C in 30 minutes and drying at the same temperature for 2 hours,
The mixture was allowed to cool to room temperature to obtain a black solid. The obtained solid is 10
From room temperature to 250 ° C under an air flow of 0 ml / min.
The temperature was raised for 30 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 =
It was 4.5% by weight.

The silica-supported ruthenium chloride catalyst (2.5 g) thus obtained was not diluted with an α-alumina carrier, but charged into a reaction tube in the same manner as in Example 1. 202 ml / min of hydrogen chloride gas,
The reaction was carried out according to Example 1, except that oxygen gas was passed at 213 ml / min. 1.7 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 0.1.
It was 49 × 10 ⁻⁴ mol / min · g-catalyst.

Comparative Example 3 A catalyst was prepared by the following method. That is, 8.0 g of powdered spherical titanium oxide (CS-300, manufactured by Sakai Chemical Industry Co., Ltd.) and crushed powder were mixed with 0.53 g of ruthenium dioxide powder (manufactured by NE Chemcat Co., Ltd.). After mixing well while grinding, the mixture was molded 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 titanium oxide carrier having a size of 12 to 18.5 mesh to dilute the catalyst. 12mm)
199 ml / min of hydrogen chloride gas and 194 of oxygen gas
The procedure was performed in accordance with Example 1 except that the solution was circulated at ml / min and the internal temperature was set to 299 ° C. 2.3 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 0.83.
× 10 ⁻⁴ mol / min · g-catalyst.

Comparative Example 4 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 was formed as the solution was dropped. After completion of the dropwise addition, the mixture was stirred at room temperature for 30 minutes, then heated with stirring and refluxed on an oil bath at 102 ° C. for 1 hour. 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,
The temperature was raised to 1 ° C. for 1 hour and 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.

To 8.0 g of the obtained titania silica powder, commercially available ruthenium chloride hydrate (RuCl ₃ .3H ₂ O, R
After impregnating a solution obtained by dissolving 1.13 g of u content (35.5% by weight) in 8.2 g of pure water, the solution was dried in air at 60 ° C. for 1 hour to carry ruthenium chloride. Next, the supported material was heated from room temperature to 300 ° C. for 1 hour and 30 minutes under a mixed gas flow of 50 ml / min of hydrogen and 100 ml / min of nitrogen for 1 hour and 30 minutes, reduced at the same temperature for 1 hour, and allowed to cool to room temperature. 8.4 g of brown titania silica-supported metal ruthenium powder was obtained.

8.4 g of the obtained titania silica-supported metal ruthenium powder was placed under an air stream of 100 ml / min.
The temperature was raised from room temperature to 600 ° C. for 3 hours and 20 minutes, and calcined at the same temperature for 3 hours to obtain 8.5 g of a gray powder. The obtained powder was molded and made to have a mesh of 12 to 18.5 to obtain a ruthenium oxide catalyst supported on titania silica. The calculated value of the content of ruthenium oxide is calculated as follows: RuO ₂ / (RuO ₂ + TiO ₂ + SiO ₂ ) × 100 =
It was 6.2% by weight. The calculated value of the ruthenium content is Ru / (RuO ₂ + TiO ₂ + SiO ₂ ) × 100 = 4.
7% by weight.

2.5 g of the thus obtained ruthenium oxide catalyst supported on titania silica was not diluted with an α-alumina carrier, but was charged into a reaction tube in the same manner as in Example 1, and hydrogen chloride gas was supplied at 180 ml / min and oxygen 180ml / min gas
The reaction was carried out in accordance with the reaction method of Example 1 except that the reaction was conducted as described above. 1.8 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 0.46 × 10 ⁻⁴ mol / min ·
g-catalyst.

Comparative Example 5 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 previously prepared by dissolving 1.34 g of commercially available ruthenium chloride (RuCl ₃ .nH ₂ O, Ru content 37.3% by weight) in 3.7 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 by hydrogen, hydrogen (20 ml / min) and nitrogen (200 ml / m
The mixture was heated from room temperature to 250 ° C. in 2 hours under a mixed gas stream of (in) for 2 hours, and reduced at the same temperature for 8 hours. After reduction, 10.3 g of a black solid was obtained. Next, the obtained solid is subjected to 35 in air.
The temperature was raised to 0 ° C. in 1 hour and calcined at the same temperature for 3 hours. 1
0.6 g of a black titanium oxide-supported ruthenium oxide catalyst was obtained. The calculated value of the content of ruthenium oxide was RuO ₂ / (RuO ₂ + TiO ₂ ) × 100 = 6.1% by weight. The calculated value of the ruthenium content was Ru / (RuO ₂ + TiO ₂ ) × 100 = 4.7% by weight.

The catalyst was prepared by thoroughly mixing 2.5 g of the thus-obtained ruthenium oxide catalyst supporting titanium oxide and 5 g of spherical titanium oxide having a diameter of 1 to 2 mm (CS-300S-12 Sakai Chemical Industry Co., Ltd.). The mixture was diluted and filled in a reaction tube in the same manner as in Example 1, and 187 ml / mi of hydrogen chloride gas
n, and carried out in accordance with Example 1 except that oxygen gas was passed at 199 ml / min. 2.0 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 2.89 ×
It was 10 ^-4 mol / min · g-catalyst.

Comparative Example 6 A catalyst was prepared by the following method. That is, 1-2 mm
0.5 g of 5.0 g of a 5 wt% supported metal ruthenium titanium oxide catalyst (manufactured by NE Chemcat Co., Ltd.)
The resultant was impregnated with an ol / l aqueous potassium chloride solution until water floated 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 solution of potassium chloride was 3.31 g for the first time and 3.24 g for the second time, and the total amount 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 a black ruthenium oxide catalyst supporting spherical titanium oxide.
9 g were obtained. The calculated value of the ruthenium oxide content was RuO ₂ / (RuO ₂ + TiO ₂ ) × 100 = 6.6% by weight. The calculated value of the ruthenium content was Ru / (RuO ₂ + TiO ₂ ) × 100 = 5.0% by weight.

The catalyst was obtained by thoroughly mixing 2.5 g of the thus obtained ruthenium oxide catalyst carrying titanium oxide and 5 g of spherical titanium oxide having a diameter of 1 to 2 mm (CS-300S-12 Sakai Chemical Industry Co., Ltd.). After dilution, the reaction tube was filled in the same manner as in Example 1 and hydrogen chloride gas was supplied at 187 ml / mi.
The reaction was performed in accordance with the reaction method of Example 1 except that n and oxygen gas were passed at 199 ml / min. Start of reaction 2.0
After a lapse of time, the activity of forming chlorine per unit weight of the catalyst was 4.03 × 10 ⁻⁴ mol / min · g-catalyst.

[0128]

As described above, according to the present invention, there is provided a supported ruthenium oxide catalyst and a method for producing chlorine, which are characterized in that they have high activity and can produce chlorine at a lower reaction temperature with a smaller amount of catalyst. Further, it was possible to provide a catalyst with less sintering of ruthenium oxide particles on a carrier which is an active species during the reaction. Further, a method for producing chlorine in which hydrogen chloride is oxidized by oxygen in the presence of the catalyst can be provided.

[Brief description of the drawings]

FIG. 1 shows EXAFS of ruthenium dioxide having a particle diameter of 10 nm or more used in Example 1, Example 2, and Comparative Example 1.
Is the radial distribution function of.

FIG. 2 is an EXAFS radial distribution function of ruthenium dioxide before and after the reaction of the catalyst used in Example 1.

FIG. 3 is an EXAFS radial distribution function of ruthenium dioxide before and after the reaction of the catalyst used in Example 2.

FIG. 4 is an EXAFS radial distribution function of ruthenium dioxide before and after the reaction of the catalyst used in Comparative Example 1.

Continued on the front page F term (reference) 4G048 AA02 AB01 AB05 AC08 AE05 4G069 AA03 AA08 BA01A BA02A BA02B BA04A BA04B BA05A BA05B BA21C BB04A BB08C BC16C BC51C BC55A BC55C BC70A BC70B BC70C BD05 CB12ECB EB07EC22 FB45 FC02 FC07

Claims (6)

[Claims] 1. A supported ruthenium oxide catalyst, which is a catalyst for producing chlorine in which one kind of oxide selected from the group consisting of oxides of Si, Zr, Al and Nb is supported on the surface of a carrier. 2. A method for producing chlorine by oxidizing hydrogen chloride with oxygen, wherein the catalyst is Si, Zr, Al, Nb.
A method for producing chlorine, which is a supported ruthenium oxide catalyst in which one kind of oxide selected from the group of oxides is supported on the surface of a carrier. 3. The production method according to claim 2, wherein the catalyst is a supported ruthenium oxide catalyst prepared by a preparation method comprising the following steps. Ruthenium compound supporting step: A step of supporting a ruthenium compound on a catalyst carrier Firing step: The product obtained in the ruthenium compound supporting step is heated at a temperature of 200 ° C. or more in an inert gas, an oxidizing gas, or a reducing gas. Firing step: An alkoxide compound supporting step: a step of supporting an alkoxide compound represented by the following formula (1) on the one obtained in the firing step: MX _n (OR) _m (1) where M = Si, Zr, Al, Nb , X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n is 0 to
4, m is in the range of 1 to 5 Oxide forming step: Step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step 4. The production method according to claim 2, wherein the catalyst is a supported ruthenium oxide catalyst prepared by a preparation method comprising the following steps. Ruthenium compound supporting step: a step of supporting a ruthenium compound on a catalyst carrier Firing step: the product obtained in the ruthenium compound supporting step is heated at a temperature of 200 ° C. or more in an inert gas, an oxidizing gas, or a reducing gas. Baking step washing step: step of washing the one obtained in the baking step with a neutral or alkaline solution alkoxide compound supporting step: supporting the alkoxide compound represented by the following formula (1) on the one obtained in the washing step Step MX _n (OR) _m (1) where M = Si, Zr, Al, Nb, X = halogen element, R = saturated alkyl group having 4 or less carbon atoms, n is 0 to 0
4, m is in the range of 1 to 5. Oxide forming step: Step of forming an oxide on the surface of the product obtained in the alkoxide compound supporting step 5. The production method according to claim 2, wherein the catalyst is a catalyst prepared by using the following ruthenium halide supporting step instead of the ruthenium compound supporting step according to claim 3 or 4. Ruthenium halide supporting step: Step of supporting ruthenium halide on a catalyst carrier 6. The production method according to claim 2, wherein the catalyst uses a carrier containing rutile crystalline titanium oxide as the carrier.