JP7150476B2 - Crystalline porous titanosilicate catalyst, method for producing the same, and method for producing p-benzoquinones using the catalyst - Google Patents

Description

The present invention relates to a crystalline porous titanosilicate catalyst, a method for producing the same, and a method for producing p-benzoquinones using the catalyst.

Aromatic dihydroxy compounds are important as intermediates or starting materials for various organic synthesis, and are used in fields such as reducing agents, rubber chemicals, dyes, pharmaceuticals, agricultural chemicals, polymerization inhibitors, and oxidation inhibitors.
Aromatic dihydroxy compounds obtained by reacting phenols with hydrogen peroxide include, for example, hydroquinone, catechol and p-benzoquinone, and the production ratio of hydroquinone, catechol and p-benzoquinone differs depending on the production method. In recent years, p-benzoquinone has been used as an intermediate for pharmaceuticals and dyes, and as a polymerization inhibitor.

Patent Document 1 discloses a method for preparing p-benzoquinone by oxidizing phenol using copper nitrate as a catalyst. Further, Patent Document 2 discloses a method of preparing a p-benzoquinone derivative by oxidizing phenols using copper chloride or copper bromide as a catalyst.

Non-Patent Document 1 discloses a method of oxidation reaction of phenol using a micrometer-sized or nanometer-sized titanosilicate catalyst.

JP-A-58-128335 JP-A-60-013734

Catal. Today, vol. 148 (2009), p174-178

In the methods for preparing p-benzoquinone and its derivatives in Patent Documents 1 and 2, the control of the reaction is still insufficient, and there is room for improvement in the selectivity and yield of p-benzoquinone. In addition, in Non-Patent Document 1, catechol and hydroquinone are mainly produced by oxidation of phenol, and p-benzoquinone is produced only slightly as a by-product. It can not be said.

The present invention provides a crystalline porous titanosilicate catalyst that can highly selectively produce p-benzoquinones by the reaction of phenols and hydrogen peroxide, a method for producing the same, and phenols and peroxides using the catalyst. An object of the present invention is to provide a method for producing p-benzoquinones by reaction with hydrogen.

The present inventors have investigated the above problems and found that (A) a silica source, (B) a titanium source, (C) a quaternary ammonium salt and water are mixed in a specific ratio, and a mixture is hydrothermally treated. , found that a crystalline porous titanosilicate catalyst having a specific structure and capable of producing p-benzoquinones with high selectivity can be produced by performing a calcination treatment, thereby completing the present invention.

That is, the present invention includes matters described in [1] to [8] below.
[1] A crystalline porous titanosilicate catalyst for producing p-benzoquinones by reacting phenols with hydrogen peroxide, comprising tetrahedral TO ₄ (T=Si or Ti, O is oxygen atoms.) A mixture having a 10-membered ring consisting of 10 units and comprising (A) a silica source, (B) a titanium source, at least one (C) quaternary ammonium salt, and water, When the quaternary ammonium salt having the largest molar amount in the mixture is used as (C1) the main quaternary ammonium salt, hydrothermal treatment is performed under the following conditions (1) and / or (2), followed by calcination. A crystalline porous titanosilicate catalyst obtained by
(1) (A) molar amount of silica source/(B) molar amount of titanium source = 10 to 20
(2) (C1) molar amount of main quaternary ammonium salt/((A) molar amount of silica source + (B) molar amount of titanium source) = 0.09 to 0.14
[2] The crystalline porous titanosilicate catalyst according to [1], wherein the (C) quaternary ammonium salt is tetrapropylammonium hydroxide or dimethyldipropylammonium hydroxide.
[3] The crystalline porous titanosilicate catalyst according to [1] or [2], wherein the crystalline porous titanosilicate catalyst has an MFI type structure or an MSE type structure.
[4] The crystalline porous titanosilicate catalyst according to any one of [1] to [3], wherein the (A) silica source is alkoxysilane and the (B) titanium source is alkoxytitanium.
[5] The crystalline porous titanium according to any one of [2] to [4], wherein the mixture further contains (C2) a quaternary ammonium salt other than tetrapropylammonium hydroxide or dimethyldipropylammonium hydroxide. Nosilicate catalyst.
[6] A mixture containing (A) a silica source, (B) a titanium source, (C) a quaternary ammonium salt and water, and (C1) a quaternary ammonium salt having the highest molar amount in the mixture The crystalline porous titano according to any one of [1] to [5], which is hydrothermally treated under the following conditions (1) and/or (2) and calcined when converted to a quaternary ammonium salt. A method for producing a silicate catalyst.
(1) (A) molar amount of silica source/(B) molar amount of titanium source = 10 to 20
(2) (C1) molar amount of main quaternary ammonium salt/((A) molar amount of silica source + (B) molar amount of titanium source) = 0.09 to 0.14
[7] A method for producing p-benzoquinones by reacting phenols with hydrogen peroxide in the presence of the crystalline porous titanosilicate catalyst according to any one of [1] to [5].
[8] The method for producing p-benzoquinones according to [7], wherein the phenol is phenol and the p-benzoquinone is p-benzoquinone.

According to the crystalline porous titanosilicate catalyst of the present invention, p-benzoquinones can be produced with high selectivity by reacting phenols with hydrogen peroxide.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments according to the present invention will be described in detail.
(Crystalline porous titanosilicate catalyst)
The crystalline porous titanosilicate catalyst of the present invention is described below.

The crystalline porous titanosilicate catalyst of the present invention consists of a tetrahedral unit of SiO4 in which oxygen is arranged at _four vertexes around a silicon center, and a _tetrahedral unit of TiO4 in which titanium is arranged instead of silicon in the center. is a porous crystalline body having regularly three-dimensionally bonded parts, and is typically a kind of zeolite. It also has a 10-membered ring formed from 10 tetrahedral units in an arbitrary ratio.

A one-dimensional, two-dimensional, or three-dimensional pore is formed by the structure of the 10-membered ring (hereinafter referred to as "10-membered ring structure"). The presence or absence of a 10-membered ring structure can be confirmed by X-ray crystal structure analysis, an electron microscope, or the like.

The crystalline porous titanosilicate catalyst of the present invention is not particularly limited as long as it has the 10-membered ring. , BOG, BOZ, CGF, CGS, CON, CSV, DAC, DFO, EUO, EWS, FER, HEU, IFW, IMF, ITG, ITH, ITR, ITT, IWR, IWW, JRY, JST, LAU, LIT, MEL , MFI, MFS, MSE, MTT, MVY, MWW, NES, OBW, OKO, PAR, PCR, PON, PSI, PUN, RON, RRO, SEW, SFF, SFG, SFS, STF, STI, SVR, SZR, TER , TON, TUN, UOS, UOV, USI, UWY, WEI, and WEN, and preferably has any one of IMF, TUN, UWY, MFI, and MSE structures. It is more preferable in that it has pores, and the structure of either MFI or MSE has a three-dimensional pore due to a slightly larger 10-membered ring with a short axis and a long axis that are similar to the size of a benzene ring. Especially preferred.

A zeolite having an MFI type structure has, for example, a 10-membered ring structure of 5.1 Å (minor diameter) × 5.5 Å (major diameter) and a 10-membered ring structure of 5.3 Å (minor diameter) × 5.6 Å (major diameter) It has three-dimensional pores due to The zeolite can be produced by various production methods, for example, a method using a structure-directing agent. Structure-directing agents include specific quaternary ammonium salts such as tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapropylammonium bromide, bis-1,6-(tripropylammonium)hexamethylene diiodide, etc. is mentioned.

Zeolites having an MSE structure include, for example, a 5.2 Å (minor diameter) × 5.8 Å (major diameter) 10-membered ring structure and a 5.2 Å (minor diameter) × 5.2 Å (major diameter) 10-membered ring structure It has three-dimensional pores due to The zeolite can be produced by various production methods, for example, a method using a structure-directing agent. Structure-directing agents include certain quaternary ammonium salts such as dimethyldipropylammonium hydroxide, N,N,N',N'-tetraethylbicyclo[2,2,2]oct-7-ene-2, It can be produced using 3:5,6-dipyrrolidinium diiodide or the like.

The structure code of IZA designates only the geometric structure of the zeolite skeleton, and even if the composition and lattice constant are different, if the geometric structure is the same, they are included in the same structure code.
The crystalline titanosilicate catalyst of the present invention has the following features in addition to having the above 10-membered ring.

Regarding the molar amounts of the raw materials (A) silica source, (B) titanium source, and (C) quaternary ammonium salt used in the production of the crystalline porous titanosilicate catalyst of the present invention, B) The ratio of the number of moles of (A) silica source to the number of moles of titanium source, which is the ratio of (A) moles of silica source/(B) moles of titanium source, is preferably 10 to 20, It is more preferably 10-15. Also, the molar amount of (C1) the primary quaternary ammonium salt, which is the ratio of the molar amount of (C1) the primary quaternary ammonium salt to the sum of the molar amounts of (A) the silica source and the titanium source The value of /(molar amount of (A) silica source + molar amount of (B) titanium source) is preferably 0.09 to 0.14, more preferably 0.10 to 0.13. .

In the present invention, (C1) the main quaternary ammonium salt is the quaternary ammonium salt having the largest molar amount when two or more quaternary ammonium salts are contained in the mixture. means For example, if tetrapropylammonium hydroxide and tetrabutylammonium hydroxide were included in the mixture, the predominant quaternary ammonium salt would be tetrapropylammonium hydroxide, with the highest molarity being tetrapropylammonium hydroxide. It is propylammonium hydroxide. Also, the main quaternary ammonium salt preferably accounts for 50% or more, more preferably 80% or more, of the total number of moles of the quaternary ammonium salts in the mixture. When the mixture contains only one quaternary ammonium salt, the quaternary ammonium salt is the main quaternary ammonium salt.

(A) The silica source is not particularly limited as long as it can produce the crystalline porous titanosilicate catalyst of the present invention. point is preferable. Examples of alkoxysilanes include tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, ethyl triethoxysilane, propyltriethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltriethoxysilane, and the like. These (A) silica sources may be used alone or in combination of two or more.

(B) The titanium source is not particularly limited as long as it can produce the crystalline porous titanosilicate catalyst of the present invention. point is preferable. Alkoxy titanium includes, for example, titanium tetrabutoxide, titanium tetraisobutoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetraethoxide, titanium tetramethoxide, titanium tetrapentoxide and the like. These titanium sources can be used alone or in combination of two or more.

(C) The quaternary ammonium salt is not particularly limited as long as it can produce the crystalline porous titanosilicate catalyst of the present invention. The one used is preferred. That is, for example, when producing an MFI type crystalline porous titanosilicate catalyst, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapropylammonium bromide, bis-1,6-(tripropylammonium) hexamethylene and diiodide. Preference is given to using tetrapropylammonium hydroxide.

Further, when producing an MSE type crystalline porous titanosilicate catalyst, dimethyldipropylammonium hydroxide, N,N,N',N'-tetraethylbicyclo[2,2,2]oct-7-ene- 2,3:5,6-dipyrrolidinium diiodide and the like. Preference is given to using dimethyldipropylammonium hydroxide.

(C) when the quaternary ammonium salt is tetrapropylammonium hydroxide or dimethyldipropylammonium hydroxide, the mixture contains (C2) a quaternary ammonium hydroxide other than tetrapropylammonium hydroxide or dimethyldipropylammonium hydroxide; It may further contain an ammonium salt. For example, when tetrapropylammonium hydroxide is selected as (C) the quaternary ammonium salt, the mixture may further contain dimethyldipropylammonium hydroxide and/or other quaternary ammonium salts as (C2). . Further, when dimethyldipropylammonium hydroxide is selected as (C) the quaternary ammonium salt, the mixture may further contain tetrapropylammonium hydroxide and/or other quaternary ammonium salts as (C2). .

Examples of other quaternary ammonium salts include tetrabutylammonium hydroxide, tetrapropylammonium bromide, N,N,N',N'-tetraethylbicyclo[2,2,2]oct-7-ene-2 , 3:5,6-dipyrrolidinium diiodide.

(Method for producing crystalline porous titanosilicate catalyst)
The method for producing the crystalline porous titanosilicate catalyst of the present invention is described below. First, (A) a silica source, (B) a titanium source, at least one (C) quaternary ammonium salt and water are stirred and mixed to prepare a mixed solution. At this time, the molar ratio of (A) the silica source to (B) the titanium source in the mixed liquid during the hydrothermal treatment is 10-20, preferably 10-15. Further, the ratio of the molar amount of (C1) the main quaternary ammonium salt to the sum of the molar amounts of (A) the silica source and (B) the titanium source in the crystalline porous titanosilicate catalyst is 0 0.09 to 0.14, preferably 0.10 to 0.13. It is presumed that the binding state and surface state of titanium, which is an active site, in the crystalline porous titanosilicate catalyst differ from those of conventional catalysts, depending on the raw material ratio during the hydrothermal treatment. Therefore, it is presumed that p-benzoquinones are produced with high selectivity in the reaction between phenols and hydrogen peroxide.

Although there is no particular limitation on the order in which the raw materials are added, it is preferable to add and mix (B) the titanium source after mixing (A) the silica source, (C) the quaternary ammonium salt and water. A surfactant or an organic solvent may also be used to facilitate mixing.

Next, the obtained mixture is subjected to hydrothermal treatment. The hydrothermal treatment can be carried out by putting the mixture in a sealed pressure-resistant container and heating it. The treatment temperature is preferably 150°C to 200°C, more preferably 170°C to 190°C. The treatment time is preferably 1 to 10 hours, more preferably 2 to 7 hours, and particularly preferably 3 to 6 hours.

Subsequently, the product obtained by the hydrothermal treatment is calcined to obtain the crystalline porous titanosilicate catalyst of the present invention. The method of firing is not particularly limited, and examples thereof include a method of firing using an electric furnace, a gas furnace, or the like. As for the firing conditions, it is preferable to heat for 1 to 10 hours in an air atmosphere. The firing temperature is preferably 400°C to 800°C, more preferably 500°C to 700°C.

It is preferable to filter the treated material using a Nutsche or the like, wash the filtered material with water, and dry it before the calcination. The drying method is not particularly limited, but it is preferable to dry uniformly and quickly. For example, external heating methods such as hot air drying and superheated steam drying, and electromagnetic heating methods such as microwave heating drying and high frequency dielectric heating drying can be used.

(Method for producing p-benzoquinones)
Hereinafter, a method for producing p-benzoquinones by reacting phenols and hydrogen peroxide in the presence of the crystalline porous titanosilicate catalyst obtained above will be described.

The phenols used in the present invention mean unsubstituted phenol and substituted phenol. Here, the substituted phenol includes, for example, a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, a butyl group and a hexyl group, or an alkylphenol substituted with a cycloalkyl group. mentioned.

Examples of phenols include phenol, 2-methylphenol, 3-methylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 2-ethylphenol, 3-isopropylphenol, 2-butylphenol, 2- Examples include cyclohexylphenol and the like, with phenol being preferred.

The crystalline porous titanosilicate catalyst obtained in the present invention is used as a catalyst for producing p-benzoquinones. Various methods such as a fixed bed, a fluidized bed, a suspended bed, and a tray fixed bed are employed as the method of packing the catalyst, and any method may be used. Further, the catalyst may be used as it is, or may be used after being shaped according to the catalyst filling method. Extrusion molding, tableting molding, tumbling granulation, spray granulation, and the like are common methods for molding the catalyst. When the catalyst is used in a fixed bed system, extrusion molding and tablet molding are preferred. For suspended bed systems, spray granulation is preferred. Drying and baking may be performed after spray granulation. The average particle size of the spray-granulated catalyst preferably ranges from 0.1 μm to 1000 μm, more preferably from 5 μm to 100 μm. When it is 0.1 μm or more, handling such as filtration of the catalyst is easy, and when it is 1000 μm or less, the performance of the catalyst is good and the strength is high, so it is preferable.

The amount of the catalyst used is preferably from 0.1 to 0.1 in terms of external ratio with respect to the total mass of the reaction solution (the total mass of liquid components in the reaction system, excluding the mass of fixed components such as catalysts). 30 mass %, more preferably in the range of 0.4 to 20 mass %. A content of 0.1% by mass or more is preferable because the reaction is completed in a short time and the productivity is improved. When it is 30% by mass or less, it is preferable because the amount of the catalyst separated and recovered is small.

Further, it is preferable that the molar ratio of hydrogen peroxide to phenols is 0.01 or more and 1 or less. In addition, the concentration of hydrogen peroxide to be used is not particularly limited, but a normal 30% concentration aqueous solution may be used, or a higher concentration hydrogen peroxide solution may be used as it is or diluted with an inert solvent in the reaction system. may be used. Solvents used for dilution include alcohols and water. Hydrogen peroxide may be added all at once, or may be added gradually over time.

The reaction temperature is preferably in the range of 30°C to 130°C, more preferably in the range of 40°C to 100°C. Although the reaction proceeds even at a temperature outside this range, the above range is preferable from the viewpoint of improving productivity. The reaction pressure is not particularly limited.

The method of the reaction is not particularly limited, and the reaction may be performed in any of a batch method, a semi-batch method, and a continuous method. In the case of a continuous system, the reaction may be carried out in a homogeneous mixing tank of suspended bed type, a plug flow type of fixed bed circulation type, or a plurality of reactors in series and/or in parallel. may be connected. From the viewpoint of equipment costs, the number of reactors is preferably 1 to 4. Moreover, when using several reactors, you may divide and add hydrogen peroxide to them.

In order to obtain p-benzoquinones from the reaction solution, the reaction solution or the separated solution containing p-benzoquinones after separation of the catalyst may be subjected to a purification treatment such as removing unreacted components and by-products. good. Purification treatment is preferably carried out on this separated liquid containing p-benzoquinones after separation of the catalyst.

The purification treatment method is not particularly limited, and specific examples include oil-water separation, extraction, distillation, crystallization, and combinations thereof. The purification treatment method, procedure, and the like are not particularly limited, but for example, the following method can be used to purify a separated liquid containing p-benzoquinones after separating the reaction liquid and the catalyst.

Oil-water separation is possible when the reaction liquid separates into two phases, an oil phase and an aqueous phase. By oil-water separation, the aqueous phase with a low p-benzoquinone content is removed to recover the oil phase. In this case, p-benzoquinones may be recovered from the separated aqueous phase by extraction or distillation, or part or all of it may be used again for the reaction. Alternatively, the catalyst separated in the catalyst separation step of the present invention or the dried catalyst may be dispersed in the separated aqueous phase and supplied to the reactor. On the other hand, the oil phase is preferably further purified by extraction, distillation, crystallization, and the like.

Solvents such as 1-butanol, toluene, isopropyl ether, and methyl isobutyl ketone are used for extraction. By combining extraction and oil-water separation, the oil-water separation can be efficiently performed. The extracting solvent is preferably separated and recovered by a distillation column and recycled for use.

Distillation may be performed on the reaction liquid immediately after catalyst separation, or may be performed on the oil phase and water phase after the oil-water separation. Further, the extract may be distilled.
When distilling the reaction solution immediately after separating the catalyst, it is preferable to first separate low-boiling components such as water and alcohols. Water and alcohols may be separated in separate distillation columns or may be separated in one distillation column.

After separating water and alcohols by the above-described oil-water separation, extraction, distillation operation, etc., the phenols may be recovered by the next distillation operation and used again in the reaction. If the recovered phenols contain water that has not been completely separated, it can be removed by azeotropic distillation by adding isopropyl ether or toluene.

This azeotropic distillation can also be performed on water before recovery of phenols or liquid after separation of alcohols. The separated water may be used again for the reaction or may be used as waste water. If the recovered phenols contain impurities such as reaction by-products other than water, they can be further separated by distillation. When the impurities are reaction by-products such as hydroquinones and catechols, they can be re-supplied to the reactor together with phenols.

After separation of the phenols, components having a boiling point higher than that of the p-benzoquinones are removed by distillation, and the p-benzoquinones can be separated by a subsequent distillation operation. The high-boiling components and p-benzoquinones can also be separated in one distillation operation by withdrawing the p-benzoquinones from the middle stage of the distillation column.
The obtained p-benzoquinones can be purified by removing impurities by distillation or crystallization, if necessary.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.
(Production of crystalline porous titanosilicate catalyst)
(Example 1)
24.0 g of distilled water, 2.0 g of Tween 20 (manufactured by Tokyo Chemical Industry Co., Ltd.), 27.0 g of 25% tetra-n-propylammonium hydroxide aqueous solution (manufactured by Tokyo Chemical Industry Co., Ltd.), 32.0 g of Tetraethoxysilane (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed in a flask and stirred at room temperature for 60 minutes to obtain a mixed solution.

A mixed solution of 3.6 g of titanium tetrabutoxide (manufactured by Kanto Chemical Co., Ltd.) and 15.6 g of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise to this mixed solution, and the mixture was further stirred at room temperature for 60 minutes. Stirred. The obtained mixed solution was filled in a Teflon autoclave container, heated and stirred at 175° C. for 18 hours, and subjected to hydrothermal treatment. The resulting solid matter was washed with distilled water, air-dried, and calcined at 500° C. under atmospheric pressure for 5 hours to obtain 7.9 g of the crystalline porous titanosilicate catalyst of Example 1.

(Example 2)
10. Manufactured under the same conditions as in Example 1, except that the amount of 25% tetra-n-propylammonium hydroxide aqueous solution was 20.3 g, the amount of tetraethoxysilane was 36.0 g, and the amount of titanium tetrabutoxide was 1.8 g. 9 g of the crystalline porous titanosilicate catalyst of Example 2 were obtained.

(Example 3)
Except that 20.3 g of 25% tetra-n-propylammonium hydroxide aqueous solution and 13.3 g of tetra-n-butylammonium hydroxide were used instead of 27.0 g of 25% tetra-n-propylammonium hydroxide aqueous solution. It was produced under the same conditions as in Example 1 to obtain 11.2 g of the crystalline porous titanosilicate catalyst of Example 3.

(Comparative example 1)
Production was carried out under the same conditions as in Example 1, except that 36.0 g of tetraethoxysilane and 1.8 g of titanium tetrabutoxide were used to obtain 10.8 g of the crystalline porous titanosilicate catalyst of Comparative Example 1. rice field.

(Comparative example 2)
Hydrothermal treatment was carried out under the same conditions as in Example 1 except that the amount of 25% tetra-n-propylammonium hydroxide aqueous solution was 13.5 g, the amount of tetraethoxysilane was 36.0 g, and the amount of titanium tetrabutoxide was 1.8 g. A crystalline porous titanosilicate catalyst of the present invention having a crystalline structure was not obtained.

(Comparative Example 3)
Distilled water was 45.6 g, 7.1 g of tetrabutylammonium bromide was used instead of the 25% tetra-n-propylammonium hydroxide aqueous solution, and 1.1 g of sodium hydroxide was added under the same conditions as in Example 1. Although hydrothermal treatment was performed, the crystalline porous titanosilicate catalyst of the present invention having a crystal structure was not obtained.

(Comparative Example 4)
Hydrothermal treatment was carried out under the same conditions as in Comparative Example 3 except that 2.7 g of triethylamine was used instead of sodium hydroxide, but the crystalline porous titanosilicate catalyst of the present invention having a crystalline structure was not obtained.

All of the crystalline porous titanosilicate catalysts produced in Examples 1 to 3 and Comparative Example 1 had a 10-membered ring structure by X-ray crystal structure analysis. X-ray crystal structure analysis was performed using a powder X-ray diffractometer (MultiFlex) manufactured by Rigaku Co., Ltd., and measured in the range of 2θ=5 to 50°.

(Performance evaluation of each catalyst)
Catechol (CL) and hydroquinone (HQ) produced by reacting phenol with hydrogen peroxide in the presence of the catalysts obtained in Examples 1 to 3 and Comparative Example 1 and under conditions in which no catalyst was added. , and p-benzoquinone (p-BQ) were measured by the method described later. From the obtained results, catechol yield (%), hydroquinone yield (%), and p-benzoquinone yield (%) were calculated from the following formulas. Table 1 shows the results.
Catechol yield (%) = (number of moles of catechol produced) / (number of moles of added hydrogen peroxide) x 100
Hydroquinone yield (%) = (number of moles of hydroquinone produced) / (number of moles of hydrogen peroxide added) x 100
Yield of p-benzoquinone (%) = (Number of moles of p-benzoquinone produced)/(Number of moles of hydrogen peroxide added) x 100

（表中、ＴＰＡＯＨはテトラｎ-プロピルアンモニウムヒドロキシドを示し、ＴＢＡＯＨはテトラｎ-ブチルアンモニウムヒドロキシドを示し、ＴＰＡＢｒはテトラプロピルアンモニウムブロミドを示す。）

(In the table, TPAOH represents tetra-n-propylammonium hydroxide, TBAOH represents tetra-n-butylammonium hydroxide, and TPABr represents tetrapropylammonium bromide.)

(Measuring method)
0.20 g of each of the crystalline porous titanosilicate catalysts obtained in Examples 1 to 3 and Comparative Example 1, 3 0 g of t-butyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.), 6.0 g of distilled water, and 4.2 g of phenol (manufactured by Kanto Kagaku Co., Ltd.) were charged and stirred with a stirrer in an oil bath. It was heated to 70°C in the medium.

While stirring this mixture, 0.46 g of 30% hydrogen peroxide solution (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 60 minutes, and the mixture was maintained for 90 minutes to allow the reaction to proceed. After cooling the reaction solution, the catalyst was filtered off, a portion of the reaction solution was taken, residual hydrogen peroxide was quantified by iodometry, and the product was quantified by gas chromatography.

The analysis conditions for gas chromatography are as follows.
Detector: Hydrogen flame ion detector Column: DB-5 (Agilent J&W), inner diameter 0.25 mm, length 60 m, film thickness 0.25 μm
Column temperature; maintained at 80°C for 10 minutes, temperature rising at 4°C/min, heating up to 280°C Inlet; 280°C
Detector temperature; 280°C
Carrier gas; Helium Flow rate; 80 ml/min

Claims (8)

A crystalline porous titanosilicate catalyst for producing p-benzoquinones by reacting phenols with hydrogen peroxide, comprising tetrahedral TO ₄ (T=Si or Ti, O represents an oxygen atom .) a mixture having a 10-membered ring consisting of 10 units and comprising (A) a silica source, (B) a titanium source, at least one (C) quaternary ammonium salt, and water; When the quaternary ammonium salt with the largest molar amount is (C1) the main quaternary ammonium salt, hydrothermal treatment under the following conditions (1) and / or (2) and calcination treatment are performed. be
The phenols are selected from phenol and alkylphenols substituted with linear or branched alkyl groups or cycloalkyl groups having 1 to 6 carbon atoms,
Crystalline porous titanosilicate catalyst.
(1) (A) molar amount of silica source/(B) molar amount of titanium source = 10 to 20
(2) (C1) molar amount of main quaternary ammonium salt/((A) molar amount of silica source + (B) molar amount of titanium source) = 0.09 to 0.14 2. The crystalline porous titanosilicate catalyst according to claim 1, wherein the (C) quaternary ammonium salt is tetrapropylammonium hydroxide or dimethyldipropylammonium hydroxide. The crystalline porous titanosilicate catalyst according to claim 1 or 2, wherein the crystalline porous titanosilicate catalyst has an MFI type structure or an MSE type structure. The crystalline porous titanosilicate catalyst according to any one of claims 1 to 3, wherein the (A) silica source is an alkoxysilane and the (B) titanium source is an alkoxytitanium. The crystalline porous titanosilicate according to any one of claims 2 to 4, wherein the mixture further comprises (C2) a quaternary ammonium salt other than tetrapropylammonium hydroxide or dimethyldipropylammonium hydroxide. catalyst. A mixture comprising (A) a silica source, (B) a titanium source, (C) a quaternary ammonium salt and water is combined with (C1) the predominant quaternary The crystalline porous titanosilicate catalyst according to any one of claims 1 to 5, wherein when it is made into an ammonium salt, it is hydrothermally treated under the following conditions (1) and / or (2) and calcined. Production method.
(1) (A) molar amount of silica source/(B) molar amount of titanium source = 10 to 20
(2) (C1) molar amount of main quaternary ammonium salt/((A) molar amount of silica source + (B) molar amount of titanium source) = 0.09 to 0.14 A method for producing p-benzoquinones by reacting phenols with hydrogen peroxide in the presence of the crystalline porous titanosilicate catalyst according to any one of claims 1 to 5. 8. The method for producing p-benzoquinones according to claim 7, wherein said phenol is phenol and said p-benzoquinone is p-benzoquinone.