JP2001097922A - Production of phenyl ester and preparation of catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrially advantageous process for the production of a phenyl ester in high catalytic activity, selectivity and stability by the reaction of benzene with a carboxylic acid and molecular oxygen. SOLUTION: The phenyl ester is produced by reacting benzene with a carboxylic acid and molecular oxygen in the presence of a catalyst containing supported metallic palladium and metallic tellurium. The catalyst is produced by supporting the catalyst components on a carrier and washing with a basic solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the reaction of benzene, carboxylic acid and molecular oxygen in the presence of a specific catalyst,
The present invention relates to a method for stably producing a phenyl ester in a high yield. The product phenyl ester, for example, phenyl acetate, can be readily hydrolyzed to produce phenol.

[0002]

2. Description of the Related Art Various methods have been proposed for producing phenyl esters by reacting benzene, carboxylic acid and molecular oxygen in the presence of a specific catalyst. For example, various methods have been proposed. It is performed in a gas phase or a liquid phase using a noble metal.

[0003] As the liquid phase reaction, for example,
No. 18219 discloses a method for producing bismuth or tellurium and an alkali metal acetate in the presence of a palladium or platinum metal as a main catalyst. This method is not industrial because the activity of the catalyst is low and a large amount of an acetate of an alkali metal is required.

In Japanese Patent Publication No. 55-15455,
As a catalyst, a catalyst comprising palladium or a palladium compound and one or two or more selected from the group consisting of cadmium, zinc, uranium, tin, lead, antimony, bismuth, tellurium, thallium and their compounds, A method for producing phenylacetate in the presence of a mixture of a metal fatty acid salt and nitric acid is disclosed. This method is also not industrial because it has a low activity of the catalyst, requires a large amount of an acetate of an alkali metal, and has a problem such as corrosion of equipment due to the use of nitric acid.

[0005]

As described above, the prior art is not satisfactory particularly in terms of industrial productivity.
Further, since an alkali metal, a metal salt, an acid and the like are added, separation and recycling are complicated, which is not industrially preferable.

The present invention has been made in view of the above problems, and has as its object a method for industrially producing a phenyl ester which does not have these problems and has high activity, high selectivity and stability. Is to provide.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems of the prior art, and have found that benzene, carboxylic acid and molecular oxygen can be converted to metallic palladium and metallic tellurium. In the method of producing a phenyl ester by reacting in the presence of a supported catalyst, by performing a specific treatment on the catalyst, high activity, high selectivity,
In addition, they have found that phenyl esters can be stably produced, and have completed the present invention.

That is, the present invention relates to a method for producing a phenyl ester by reacting benzene, carboxylic acid and molecular oxygen in the presence of a catalyst carrying metal palladium and metal tellurium, wherein palladium and tellurium are used as the catalyst. Is carried out on a carrier, followed by washing with a basic solution.

Hereinafter, the present invention will be described in detail.

In the method of the present invention, a catalyst is used which is obtained by supporting metal palladium and metal tellurium on a carrier and then washing with a basic solution.

In the method of the present invention, the palladium raw material and tellurium raw material used for preparing the catalyst are not particularly limited. As the palladium raw material, for example, palladium metal, ammonium hexachloropalladate, potassium hexachloropalladate, sodium hexachloropalladate, ammonium tetrachloropalladate,
Potassium tetrachloropalladate, sodium tetrachloropalladate, potassium tetrabromobromopalladate, palladium oxide, palladium chloride, palladium bromide, palladium iodide, palladium nitrate, palladium acetate, potassium dinitrosulfite palladium,
Chlorocarbonyl palladium, dinitrodiammine palladium nitrate, tetraammine palladium nitrate, dichlorodiamine palladium, dichloro (ethylenediamine) palladium, potassium tetracyanopalladate and the like are used. As the tellurium raw material, metal tellurium, tellurium chloride (II), (IV) , Tellurium (IV) oxide, (V
I), telluric acid (H ₆ TeO ₆ ), potassium tellurate, sodium tellurate and the like are used.

As the catalyst carrier used in the method of the present invention, those which are inert to the reaction per se are preferable, and examples thereof include alumina, silica, silica alumina, activated carbon, and diatomaceous earth. Can be

In the method of the present invention, the amount of palladium supported on the carrier is 0.01 to 1 as palladium metal based on the total weight of palladium, tellurium, and the carrier.
0% by weight, preferably in the range of 0.1 to 5% by weight.

In the method of the present invention, the tellurium / palladium ratio is preferably 0.01 to 10 in terms of metal atomic ratio.
When the tellurium / palladium ratio is less than 0.01, the effect of adding tellurium is not sufficient, and when it is more than 10, the activity may be rather lowered.

The palladium and tellurium supported on a carrier is a metal state, further palladium and tellurium Pd ₃
It preferably has a Te alloy structure.

The method for preparing the catalyst is not particularly limited, and a conventionally known method for supporting a catalyst component on a carrier, for example, an impregnation method, a deposition method, an ion exchange method, or the like is used.

When preparing by the impregnation method, the palladium raw material and the tellurium raw material may be impregnated and supported at the same time, or one of them may be impregnated and supported, and then the other raw material may be impregnated and supported. In order to carry palladium and tellurium more uniformly, it is preferable to carry out impregnation at the same time.

After the support, the solvent is removed by an operation such as decantation, filtration, heating or heating under reduced pressure according to a conventional method of an impregnation method or an ion exchange method.

After the removal of the solvent, drying by heating, drying under reduced pressure, or the like can be used.

After drying, palladium and tellurium compounds may be decomposed by firing and then reduced. When calcination is performed, oxygen or oxygen diluted with an inert gas such as nitrogen, helium, argon or the like, or 200 to 7 in an air atmosphere is used.
It is good to carry out at 00 ° C.

A known method is used for the reduction to the catalyst. For example, a gas phase reduction method using hydrogen, carbon monoxide, ethylene, methanol, or the like as a reducing agent, or a liquid phase reduction method using hydrazine hydrate, formalin, formic acid, or the like can be used. In the case of the gas phase reduction method, the reduction temperature is 100 to 70.
It is carried out at 0 ° C, preferably at 200 to 600 ° C.

The washing treatment with a basic solution is preferably performed after reduction. If a washing treatment with a basic solution is performed before reduction, a large amount of the supported catalyst component elutes, which is not preferable. Examples of the basic solution include lithium hydroxide, lithium carbonate, lithium acetate, sodium hydroxide,
Hydroxides, carbonates, and carbonates of metals belonging to Group I of the periodic table such as sodium carbonate, sodium acetate, potassium hydroxide, potassium carbonate, potassium acetate, rubidium hydroxide, rubidium carbonate, rubidium acetate, cesium hydroxide, cesium carbonate, and cesium acetate An aqueous salt or carboxylate solution or an aqueous ammonia solution can be used. The temperature of the washing treatment with the basic solution is from room temperature to 100 ° C., and the time is from 0.1 to 12 hours. The concentration of the basic aqueous solution is 0.00001-6N
Can be done with If the concentration is higher than 6N, dissolution of palladium or the carrier may occur, and 0.00001
If it is less than N, it is not preferable because there is no effect of the washing treatment of the basic solution. The amount of the basic solution was 0.1 g per 1 g of the catalyst.
~ 1000 ml. After removing the basic solution, it may be washed with distilled water or the like. Drying is heat drying,
Drying under reduced pressure or the like can be performed.

The washing treatment of the basic solution may be repeated, but if the washing treatment is performed too much, the activity may be reduced in some cases.

In the method of the present invention, the reaction with benzene, carboxylic acid and molecular oxygen is carried out in the presence of a catalyst in a gas phase or a liquid phase, but is preferably carried out in a liquid phase.

The reactor is not particularly limited, and a conventionally known method, for example, a fixed-bed flow reactor, a batch reactor, a suspension bed, or the like is used.

In the method of the present invention, the number of carbon atoms is 10
Although not more than carboxylic acids can be used, lower carboxylic acids such as acetic acid and propionic acid are preferred.

The ratio of benzene to carboxylic acid can be freely changed, but preferably the benzene / carboxylic acid molar ratio is in the range of 1 / 0.1 to 1/100.

The amount of the catalyst used depends on the reaction method and cannot be specified uniformly. However, considering the economic efficiency,
For example, in the case of a fixed bed, the unit catalyst volume and the total supply amount of benzene and carboxylic acid per unit time (LHSV) are in the range of 0.1 to 50 h ^-1 , preferably 0.1 to 30 h ^-1.
h- ¹ is preferable, and in the case of a suspension bed, the catalyst concentration is preferably in the range of 0.05 to 30% by weight based on the raw material.

[0029] The reaction temperature is 100 to 300 ° C, preferably 100 to 250 ° C.

The reaction pressure may be 1 kg / cm ² or more, preferably 1 to 100 kg / cm ² .

In the method of the present invention, oxygen is used as an oxidizing agent. Oxygen may be diluted with an inert gas such as nitrogen, helium, or argon, and air may be used. The optimum supply amount of oxygen varies depending on the reaction temperature, the amount of the catalyst, and the like, but it is sufficient that the gas composition at the position passing through the catalyst is less than the explosion range.

The reaction time varies depending on how to set the reaction temperature, pressure, amount of catalyst, etc., or the reaction method, so that it is difficult to define its range in a straightforward manner. In the case of the formula, 0.5 hours or more is required. In a continuous reaction using a suspension bed or a continuous reaction using a fixed bed, the residence time may be 0.03 to 10 hours.

[0033]

According to the method of the present invention, when benzene, carboxylic acid and molecular oxygen are reacted in the presence of a catalyst on which metal palladium and metal tellurium are supported to produce a phenyl ester, By using a catalyst component supported on a carrier and then washed with a basic solution, phenylacetate can be industrially and advantageously produced with high activity, high selectivity, and stably. Is also very significant.

[0034]

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 1.3 g of telluric acid was dissolved in 20 ml of distilled water, and then 14.4 g of a 8.3% by weight dinitrodiammine palladium nitric acid solution was added.
The volume was 1 ml. To this aqueous solution, 40 g of silica beads (Caractact Q-30 (manufactured by Fuji Silysia)) was added and impregnated. After impregnation, it was dried under reduced pressure at 50 ° C. and 50 mbar, and further dried under vacuum at 100 ° C. for 3 hours.

Next, it was calcined at 400 ° C. for 5 hours in air, and then reduced at 400 ° C. in a hydrogen atmosphere.

After the reduction, washing with a basic solution was performed as follows. 50m of 0.01N potassium hydroxide aqueous solution
2 g of the substance after the reduction was added to 1 and stirred at room temperature for 3 hours. Then, after removing the potassium hydroxide aqueous solution, it was washed with distilled water and dried at 110 ° C. for 3 hours.

As a result of XPS measurement, palladium and tellurium of the obtained catalyst were Pd3d5 / 2 and Te, respectively.
It was confirmed from the binding energy of 3d5 / 2 that it was in a metallic state. Also, as a result of X-ray diffraction, 2θ = 39.9 °,
40.4 ° shows a main peak, and ASTM-No. 11-
0451 was consistent with the diffraction pattern of the Pd ₃ Te alloy.

The reaction was carried out using a stainless steel small autoclave of 10 ml. The previously prepared catalyst was replaced with 2
After the mesh was reduced to 00 mesh or less, 0.2 g was used. 1.1 g of benzene and 0.8 g of acetic acid were added to the autoclave,
Introducing oxygen 1 kg / cm @ 2, a nitrogen 6 kg / cm ² was added the total pressure was 7 kg / cm ^2. The reaction temperature was 190 ° C., and the reaction was performed for 30 minutes. The generated phenyl acetate was 110 μmol.

Example 2 [0040] Except that an aqueous ammonia solution was used as the basic solution,
A catalyst was prepared in the same manner as in Example 1.

The obtained catalyst was analyzed by XPS. As a result, palladium and tellurium were Pd3d5 / 2 and Te, respectively.
It was confirmed from the binding energy of 3d5 / 2 that it was in a metallic state. The obtained catalyst was analyzed by X-ray analysis to obtain 2θ
= 39.9 °, 40.4 °, showing a main peak, AS
TM-No. This was consistent with the diffraction pattern of 11-0451 Pd ₃ Te alloy.

The reaction was carried out under the same conditions as in Example 1.
The generated phenyl acetate was 119 μmol.

Comparative Example 1 After reduction, except that no washing treatment with a basic solution was performed.
A catalyst was prepared in the same manner as in Example 1.

The obtained catalyst was analyzed by XPS. As a result, palladium and tellurium were Pd3d5 / 2 and Te, respectively.
It was confirmed from the binding energy of 3d5 / 2 that it was in a metallic state. As a result of X-ray analysis, 2θ = 39.9 °,
40.4 ° shows a main peak, and ASTM-No. 1
1-0451 consistent with the diffraction pattern of Pd ₃ Te alloy.

The reaction was carried out under the same conditions as in Example 1.
The generated phenyl acetate was 14 μmol.

Example 3 Except that the number of times of the washing treatment with the basic solution was twice,
A catalyst was prepared in the same manner as in Example 2.

As a result of XPS measurement, palladium and tellurium of the obtained catalyst were Pd3d5 / 2 and Te, respectively.
It was confirmed from the binding energy of 3d5 / 2 that it was in a metallic state. The obtained catalyst was analyzed by X-ray analysis to obtain 2θ
= 39.9 °, 40.4 °, showing a main peak, AS
TM-No. This was consistent with the diffraction pattern of 11-0451 Pd ₃ Te alloy.

The reaction was carried out under the same conditions as in Example 1.
The generated phenyl acetate was 128 μmol.

Example 4 10 ml (4.1 g) of the catalyst prepared in the same manner as in Example 3 was charged into a stainless steel reaction tube having an inner diameter of 1.3 cm. A mixture of benzene and acetic acid (1: 1 (molar ratio)) is 2.2 min / min.
g, 27 ml / min oxygen, 183 ml / min nitrogen,
The reaction was conducted at a reaction pressure of 20 kg / cm ² and a reaction temperature of 190 ° C.

After the reaction, the reaction products were collected at 24 hours and 120 hours, and analyzed by gas chromatography.
The ratio of the amount of phenyl acetate produced at 120 hours to the amount of phenyl acetate produced at 24 hours (120 hr / 24 hr) was used as an indicator of the activity decrease. Table 1 shows the results.

[0051]

[Table 1]

Comparative Example 2 10 ml (4.1 g) of a catalyst prepared in the same manner as in Comparative Example 1
And the reaction was carried out under the same reaction conditions as in Example 4.

After the reaction, the reaction product was collected at 24 hours and 120 hours as in Example 4, and analyzed by gas chromatography. The ratio of the amount of phenyl acetate produced at 120 hours to the amount of phenyl acetate produced at 24 hours (120 hr / 24 hr) was used as an indicator of the activity decrease. The results are shown in Table 1.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4H006 AA02 AC48 BA25 BA27 BA81 BE30 BJ50 KA10 4H039 CA66 CC20 CD10 CD40

Claims (7)

[Claims] 1. A method for producing a phenyl ester by reacting benzene, carboxylic acid and molecular oxygen in the presence of a catalyst supporting metal palladium and metal tellurium, wherein a catalyst component is supported on a carrier as the catalyst. After
A method for producing a phenyl ester, comprising using a product washed with a basic solution. 2. The method for producing a phenyl ester according to claim 1, wherein the basic solution is an aqueous solution of a hydroxide, carbonate or carboxylate of a Group I metal of the periodic table. 3. The method for producing a phenyl ester according to claim 1, wherein the basic solution is an aqueous ammonia solution. 4. In preparing a catalyst for producing a phenyl ester from benzene, carboxylic acid and molecular oxygen in which metal palladium and metal tellurium are supported on a carrier, after supporting a catalyst component on the carrier, A method for preparing a catalyst for producing a phenyl ester, comprising washing with a basic solution. 5. The preparation method according to claim 4, wherein the catalyst component is carried on a carrier, reduced, and then washed with a basic solution. 6. The method according to claim 4, wherein the basic solution is an aqueous solution of a hydroxide, carbonate or carboxylate of a Group I metal of the periodic table. 7. The preparation method according to claim 4, wherein the basic solution is an aqueous ammonia solution.