JP2010126466A - Method for producing phenol - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an economical and environmentally friendly production method of phenol. <P>SOLUTION: The method for producing phenol includes oxidizing benzene in the presence of a vanadium complex-including zeolite catalyst that includes zeolite and a vanadium complex included therein, a saccharide as a reducing agent, a solvent and molecular oxygen. The vanadium complex is inhibited from eluting into a reaction liquid by inclusion in zeolite of the vanadium complex used as the catalyst. As the vanadium complex-including zeolite catalyst still holds the vanadium complex after the reaction, it can be filtered out and washed to be reutilized. The use of a saccharide as the reducing agent permits ready disposal of waste liquid, and the method is environmentally friendly. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing phenol.

  Conventionally, the cumene method has been used as a method for producing phenol. In this method, phenol is produced from benzene through the following three steps. That is, (1) benzene and propylene are reacted in the presence of an acid catalyst to produce cumene. (2) The cumene obtained is reacted with oxygen to produce cumene hydroperoxide. (3) The resulting cumene hydroperoxide is decomposed to produce phenol and acetone in the presence of an acid catalyst.

  However, since the cumene method comprises a three-stage process, the equipment is complicated and not economical. Further, the cumene method requires a large amount of acid treatment, and thus has a problem from the environmental viewpoint. In addition to the cumene method, as a method for producing phenol, a method of oxidizing benzene using hydrogen peroxide in an acidic liquid in which a Fenton reagent is present is known. However, this method is not suitable for industrialization due to the difficulty in handling hydrogen peroxide.

  Thus, various methods for producing phenol in one step by directly oxidizing benzene have been proposed. For example, Patent Document 1 discloses a method of oxidizing benzene with a molecular oxygen-containing gas by coexisting amines at a ratio of 0.0001 to 0.2 mole per mole of benzene. In Patent Document 2, a liquid phase oxidation reaction is carried out using an oxidizing agent in the presence of copper ion or palladium as a catalyst to produce phenol, and at the time of producing phenol, at least quaternary ammonium ions and crown ether are contained in the reaction solution. A method of adding one species is disclosed.

Patent Document 3 discloses a method in which benzene, ascorbic acid as a reducing agent, and a vanadium-supported alumina catalyst are put in an acetic acid aqueous solution solvent, and benzene is directly oxidized in an oxygen atmosphere to generate phenol. Patent Document 4 discloses a method of directly oxidizing benzene in the presence of a catalyst containing a solid oxide modified with a vanadium compound and a palladium-based substance and oxygen.
JP-A-4-210658 Japanese Patent Laid-Open No. 4-273836 JP 2000-212112 A JP 2006-247496 A

  As described above, various methods for producing phenol in one step by directly oxidizing benzene have been proposed, but all have room for improvement in terms of economy and environment.

  The present invention has been made in view of the above circumstances, and provides a method for producing phenol in one step by directly oxidizing benzene, which is economical and environmentally friendly. The purpose is to do.

  The method for producing phenol according to the present invention that solves the above-described problems is a method for oxidizing benzene in the presence of a vanadium complex-encapsulating zeolite catalyst in which a vanadium complex is encapsulated in zeolite, a saccharide as a reducing agent, a solvent, and molecular oxygen. It is characterized by doing.

  That is, it can suppress that a vanadium complex elutes in a reaction liquid by making the zeolite encapsulate the vanadium complex used as a catalyst. Further, since the vanadium complex-containing zeolite catalyst after use still retains the vanadium complex, it can be reused by filtering and washing from the reaction solution. Furthermore, since saccharides are used as the reducing agent in the present invention, the waste liquid can be easily treated and is environmentally friendly. As a result, according to the method for producing phenol of the present invention, phenol can be produced economically and environmentally friendly.

  The vanadium complex constituting the vanadium complex-encapsulating zeolite catalyst includes at least one selected from the group consisting of vanadium 2-pyrazinecarboxylate, vanadylacetylacetonate, vanadium 2-pyridinecarboxylate, and vanadium 2-quinolinecarboxylate. Is preferred. Moreover, Y-type zeolite is suitable as the zeolite constituting the vanadium complex-encapsulating zeolite catalyst.

  The saccharide is preferably at least one selected from the group consisting of glucose, fructose and sucrose. The amount of the saccharide used is preferably 0.03 mol to 0.15 mol with respect to 1 mol of benzene. The solvent is preferably an acetic acid aqueous solution having a concentration of 10 vol% to 50 vol%.

  According to the present invention, phenol can be produced in one step by directly oxidizing benzene, and more economical and environmentally friendly phenol can be produced.

  The phenol production method of the present invention is characterized in that benzene is oxidized in the presence of a vanadium complex-encapsulated zeolite catalyst in which a zeolite contains a vanadium complex, a saccharide as a reducing agent, a solvent, and molecular oxygen. To do.

  First, the vanadium complex-containing zeolite catalyst used in the present invention will be described.

  The vanadium complex-encapsulating zeolite catalyst is one in which a vanadium complex is encapsulated in pores of zeolite.

  As the vanadium complex constituting the vanadium complex-encapsulating zeolite catalyst, vanadium in the vanadium complex can be reduced by a saccharide described later, that is, the vanadium valence in the vanadium complex is tetravalent or pentavalent. If there is, it will not be specifically limited.

Examples of the vanadium complex include vanadium 2-pyrazinecarboxylate (V (H ₆ C ₁₀ N ₄ O ₄ )), vanadyl acetylacetonate (VO (acac) ₂ ), vanadium 2-pyridinecarboxylate (V (H ₈ C ₁₂ N ₂ O ₄ )), vanadium 2-quinolinecarboxylate (V (H ₁₂ C ₁₈ N ₂ O ₄ )) and the like. These vanadium complexes may be used alone or in combination of two or more. Among these, as the vanadium complex used in the present invention, vanadium 2-pyrazinecarboxylate (V (H ₆ C ₁₀ N ₄ O ₄ )) and vanadyl acetylacetonate (VO (acac) ₂ ) are preferable.

  The zeolite constituting the vanadium complex-encapsulating zeolite catalyst is not particularly limited as long as the vanadium complex can be encapsulated in the pores, and so-called zeolite-like substances can also be used.

As the zeolite, the entrance of pores such as analsim, chabazite, erionite, gismondine, ZK-5, A-type zeolite, natrolite, poringite, yugawaralite is formed by a ring structure having 8 or less oxygen atoms ( oxygen 8-membered ring or less) small pore _{zeolites; AlPO 4 -11, EU-1} , ferrierite, heulandite, ZSM-11, ZSM-5 , NU-87, theta-1, the entrance of the pores, such Weinebeaito are formed by the oxygen atoms 10 ring structure (oxygen 10-membered ring) medium pore _{zeolite; AlPO 4 -5, AlPO 4 -31} , beta zeolite, CIT-1, X-type zeolite, Y type zeolite, Entering pores such as gmelinite, L-type zeolite, mordenite, ZSM-12, and offretite Mouth is formed by the oxygen atoms 12 ring structure (oxygen 12-membered ring) large pore zeolites, clover _{light, VPI-5, AlPO 4 -8} , pores, such as CIT-5, UTD-1 Examples thereof include ultra-large pore zeolites whose entrance is formed of a ring structure having 14 or more oxygen atoms (oxygen 14-membered ring or more). These zeolites may be used alone or in combination of two or more.

Here, if the entrance of the pores of the zeolite is too small, reaction raw materials such as benzene will not easily enter the pores, and the reaction rate of phenol formation tends to be slow, whereas if the entrance is too large The vanadium complex may not be stably retained. Therefore, as the _{zeolite, AlPO 4 -5, AlPO 4 -31} , beta zeolite, CIT-1, X-type zeolite, Y-type zeolite, gmelinite, L type zeolite, mordenite, ZSM-12, pores, such as offretite Is preferably a large-pore zeolite formed by a ring structure having 12 oxygen atoms (oxygen 12-membered ring), particularly Y-type zeolite. The entrance diameter of the Y-type zeolite is 0.7 nm to 1.2 nm.

Y-type zeolite can be classified into, for example, H-Y type zeolite, Na-Y type zeolite, NH ₄ -Y type zeolite, and the like depending on the type of exchange cation. Among these, as the Y-type zeolite used in the present invention, H-Y type zeolite is particularly preferable. The reason why the H—Y type zeolite is preferable is not necessarily clear, but is thought to be because hydrogen ions (H ⁺ ) are easily given to molecular oxygen. That is, in the method for producing phenol of the present invention, it is considered that phenol is generated via the reaction pathways of reaction formulas (1) to (5) described later. In the reaction of this reaction formula (2), H-Y zeolite is considered to have the highest activity.

The vanadium complex-encapsulating zeolite catalyst preferably includes a vanadium complex having a molecular diameter larger than the entrance diameter of the pores of the zeolite. That is, it is preferable that the vanadium complex cannot substantially pass through the entrance of the pore. Thereby, elution of the vanadium complex from the zeolite can be further suppressed. From this point of view, as the vanadium complex-encapsulating zeolite catalyst, vanadium 2-pyrazinecarboxylate (V (H ₆ C ₁₀ N ₄ O ₄ )), vanadium 2-pyridinecarboxylate (V (H ₈₎ C ₁₂ N ₂ O ₄ )) and vanadium complexes such as vanadium 2-quinolinecarboxylate (V (H ₁₂ C ₁₈ N ₂ O ₄ )) are preferred.

  In addition, the vanadium complex inclusion | inner_cover zeolite catalyst in which the vanadium complex which has a larger molecular diameter than the entrance diameter of the pore which the zeolite has as mentioned above is included can be obtained by the ship-in-bottle method, for example.

  Hereinafter, as an example of the vanadium complex-encapsulating zeolite catalyst, a manufacturing method by a ship-in-bottle method will be described. The ship-in-bottle method includes a step of encapsulating vanadium in the pores of the zeolite; and a step of synthesizing a vanadium complex in the pores of the zeolite.

  In the step of encapsulating vanadium in the pores of the zeolite, for example, the zeolite is dispersed in a solution containing vanadium ions, mixed and stirred for a predetermined time under reflux conditions, so that vanadium is contained in the pores of the zeolite. Can be included.

  As the solution containing vanadium ions, for example, an aqueous solution in which a vanadium compound such as vanadium oxysulfate is dissolved in water is preferable. The concentration of the vanadium compound in the aqueous solution is preferably 0.01 mol / l to 0.1 mol / l in terms of vanadium ions. What is necessary is just to adjust the usage-amount of the said vanadium compound suitably with the vanadium inclusion amount desired. For example, when vanadium is included in the H-Y zeolite, the amount of vanadium ions with respect to 1 g of the H-Y zeolite is preferably 1.0 mmol to 5.0 mmol.

  The temperature of the solution when the zeolite is charged and mixed and stirred is preferably 70 ° C to 80 ° C. The stirring time is preferably 48 hours to 72 hours. Then, the precipitate is filtered from the stirred solution, and the filtrate is washed with an appropriate solvent (for example, water, acetone, etc.). Vanadium-containing zeolite can be obtained by drying the filtrate after washing at 100 to 120 ° C. for 20 to 24 hours.

  In the step of synthesizing the vanadium complex in the pores of the zeolite, for example, the vanadium-encapsulated zeolite obtained in the above step and the ligand precursor are put into a solvent and mixed and stirred for a predetermined time under reflux conditions. Thus, a vanadium complex-encapsulated zeolite can be obtained.

  The ligand precursor is not particularly limited as long as it can form a complex with vanadium. For example, 2-pyrazinecarboxylic acid, 2-pyridinecarboxylic acid, 2-quinolinecarboxylic acid and the like are preferable. These ligand precursors may be used alone or in combination of two or more. The amount of the ligand precursor used is preferably 2.0 mmol to 5.0 mmol with respect to 1 g of the vanadium-containing zeolite obtained as described above.

  Although the said solvent is not specifically limited, For example, ethanol is suitable.

  The temperature of the solvent when mixing and stirring the vanadium-encapsulated zeolite and the ligand precursor is preferably 50 ° C to 60 ° C. The stirring time is preferably 12 hours to 24 hours. Then, the precipitate is filtered from the stirred solution, and the filtrate is washed with an appropriate solvent (for example, water, acetone, etc.). By drying the filtrate after washing at 100 to 120 ° C. for 20 to 24 hours, a vanadium complex-encapsulating zeolite catalyst can be obtained.

  In addition, in order to further reduce impurities contained in the obtained vanadium complex-containing zeolite catalyst, it is also preferable to stir again under methanol at 50 ° C. to 60 ° C. for 2 hours to 4 hours before drying.

  Next, the saccharide used as the reducing agent will be described.

  The saccharide is not particularly limited as long as it can reduce vanadium in the vanadium complex. In addition, even non-reducing sugars such as sucrose can be used that exhibit reducing properties when hydrolyzed in a reaction solvent.

  Examples of the saccharide include trioses such as glyceraldehyde and dihydroxyacetone; tetroses such as erythrose, threose and erythrulose; pentoses such as ribose, lyxose, xylose, arabinose, xylulose and ribulose; allose, talose, gulose, glucose, altrose, Monosaccharides such as mannose, galactose, idose, psicose, fructose, sorbose gatoose; monosaccharides: sucrose, trehalose, isotrehalose, cordobiose, solohorse, nigerose, laminaribiose, maltose, cellobiose, isomaltose, isomaltose, etc. Disaccharides: maltotriose, isomaltotriose, panose, cellotriose, soratriose Trisaccharides such as melezitose, planteose, gentianose, umbelliferose, lactosucrose, raffinose: tetrasaccharides such as maltotetraose, isomaltotetraose, stachyose, cellotetraose, scorodose, liquinose, panose: maltopentaose, iso Pentasaccharides such as maltopentaose: polysaccharides such as starch. These saccharides may be used alone or in combination of two or more. Among these, water-soluble saccharides such as dihydroxyacetone, erythrose, lyxose, allose, talose, growth, glucose, altrose, idose, fructose, sucrose, trehalose, gentiobiose are preferable, and glucose, fructose, Sucrose is more preferable, and sucrose is particularly preferable because it has the highest activity.

  The amount of the saccharide used is preferably 0.03 mol or more, more preferably 0.05 mol or more, still more preferably 0.07 mol or more, and 0.15 mol or less with respect to 1 mol of benzene as a reaction raw material. More preferably, it is 0.10 mol or less, More preferably, it is 0.08 mol or less. If the usage-amount of the saccharide with respect to 1 mol of raw material benzene is 0.03 mol or more, the yield of the phenol obtained can be improved more without lack of a reducing agent. On the other hand, when the amount of saccharide used relative to 1 mol of raw material benzene exceeds 0.15 mol, the yield of phenol tends to decrease. The reason why the yield of phenol decreases due to an increase in the amount of saccharide used is not necessarily clear, but it is considered that a part of the produced phenol is reoxidized to produce benzoquinone.

  Next, the solvent used in the present invention will be described.

  The solvent is not particularly limited. The solvent is preferably pH 4 or more, more preferably pH 5 or more, further preferably pH 6 or more, preferably pH 10 or less, more preferably pH 9 or less, and further preferably pH 8 or less. By setting the solvent to pH 4 or higher, benzene can be more easily dissolved, and by setting the pH to 10 or lower, it is possible to further suppress the elution of the vanadium complex from the vanadium complex-containing zeolite catalyst.

In the method for producing phenol according to the present invention, it is considered that phenol is generated via reaction pathways of reaction formulas (1) to (5) described later. In the reaction of reaction formula (2), hydrogen ions are produced. (H ⁺ ) is considered to be important. Therefore, an acidic solvent is suitable as the solvent used in the present invention.

  Examples of the acidic solvent include inorganic acid aqueous solutions such as hydrogen chloride, nitric acid, sulfuric acid, phosphoric acid, boric acid, and carbonic acid; organic acid aqueous solutions such as acetic acid, oxalic acid, citric acid, succinic acid, amino acids, and ascorbic acid. Can be mentioned. Among these, an acetic acid aqueous solution is preferable because it is more environmentally friendly.

  The aqueous acetic acid solution preferably has a concentration of 10 vol% or more, more preferably 15 vol% or more, still more preferably 20 vol% or more, preferably 50 vol% or less, more preferably 40 vol% or less, still more preferably 30 vol%. % Or less. By setting the acetic acid concentration in the above range, the pH of the solvent can be easily adjusted to a desired value.

  Next, molecular oxygen will be described.

  The amount of the molecular oxygen used is preferably 2.3 mol or more, more preferably 2.5 mol or more, still more preferably 3.6 mol or more, and 6.1 mol with respect to 1 mol of benzene as a reaction raw material. It is preferable to set it as follows, More preferably, it is 5.4 mol or less, More preferably, it is 4.3 mol or less. If the amount of molecular oxygen used relative to 1 mol of the raw material benzene is 2.3 mol or more, the oxidizing agent is not deficient, and the oxidation-reduction reaction cycle proceeds well, that is, the oxygen atoms are not deficient. The yield of phenol can be further improved. On the other hand, if the amount of molecular oxygen used per 1 mol of the raw material benzene is 6.1 mol or less, the oxidation-reduction reaction cycle proceeds well, and hydroquinone, benzoquinone, catechol, etc. are generated by sequential oxidation of phenol, or complete oxidation. The generation of COx due to can be suppressed.

  Next, reaction conditions in the method for producing phenol of the present invention will be described.

  In the method for producing phenol of the present invention, benzene is directly oxidized in the presence of the vanadium complex-containing zeolite catalyst, a saccharide as a reducing agent, a solvent, and molecular oxygen to obtain phenol. Here, in the method for producing phenol of the present invention, phenol is produced by direct oxidation of benzene with the production of hydrogen peroxide through the reaction pathways shown in the following reaction formulas (1) to (5). It is thought that.

  The production method of the present invention can be carried out by various reaction methods and reaction operations such as batch method, semi-batch method, and continuous method. Moreover, what is necessary is just to select a reaction container suitably according to the reaction system and reaction operation to employ | adopt.

  The reaction temperature in the method of the present invention is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, further preferably 80 ° C. or higher, preferably 95 ° C. or lower, more preferably 90 ° C. or lower, and further Preferably it is 85 degrees C or less. If the said reaction temperature is 60 degreeC or more, the oxidation reaction of benzene will advance easily and the yield of phenol will improve more. Moreover, if the said reaction temperature is 95 degrees C or less, the production | generation of a by-product can be suppressed and the yield of a phenol will improve more.

  The reaction time in the method of the present invention is preferably 12 hours or more, more preferably 15 hours or more, further preferably 20 hours or more, preferably 30 hours or less, more preferably 26 hours or less, and further Preferably it is 24 hours or less. When the reaction time is 12 hours or longer, the oxidation reaction of benzene proceeds sufficiently and the yield of phenol is further improved. On the other hand, even if the reaction time exceeds 30 hours, the yield of phenol is not improved so much and it is not economical.

  The reaction pressure of the present invention is preferably 0.1 MPa or more and 1.0 MPa or less. The reaction pressure can be adjusted by the pressure of molecular oxygen in the reactor. The reaction pressure is preferably adjusted only with molecular oxygen, but may be adjusted using molecular nitrogen, argon or the like to the extent that the effects of the present invention are not impaired.

  The oxygen pressure in the method of the present invention is preferably 0.1 MPa or more, more preferably 0.4 MPa or more, further preferably 0.6 MPa or more, and preferably 1.0 MPa or less, more preferably 0. .9 MPa or less, more preferably 0.7 MPa or less. When the oxygen pressure is 0.1 MPa or more, the oxidizing agent is not insufficient and the oxidation-reduction reaction cycle proceeds well. Moreover, if the said oxygen pressure is 1.0 Mpa or less, since advancing of the sequential oxidation of phenol will be suppressed, a phenol selectivity will improve.

  The phenol produced after the reaction can be separated and purified by appropriately combining the reaction solution after the reaction with solvent extraction, distillation, alkali treatment, acid treatment and the like. The used vanadium complex-encapsulating zeolite catalyst can be reused by filtering it from the reaction solution and washing it. In addition, what is necessary is just to wash | clean the vanadium complex inclusion | inner_cover zeolite catalyst after use, for example with acetone.

  Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples, and all modifications and embodiments without departing from the gist of the present invention are not limited thereto. Included in range.

[Evaluation methods]
1. V content V content in each catalyst was measured using a fluorescent X-ray analyzer (XRF) (Rigaku Corporation, "Primini (registered trademark)"). Specifically, a cell sheet was stretched on the bottom of the XRF sample cup, and the sample was uniformly placed thereon, followed by covering with a nylon filter net for measurement.

2. Liquid Phase Chromatographic Measurement Liquid phase chromatographic measurement was performed using the following apparatus, mobile phase and measurement conditions.
(1) High-performance liquid chromatograph configuration Liquid feed pump: PU-2080 (manufactured by JASCO)
Detector: MD-2010 (manufactured by JASCO)
Column oven: CO-2065Plus (manufactured by JASCO)
(2) Mobile phase A solution of acetonitrile (manufactured by Nacalai Tesque, high-performance liquid chromatographic reagent) and B solution of 0.1% by volume of trifluoroacetic acid aqueous solution (manufactured by Nacalai Tesque, high-performance liquid chromatographic characteristic reagent) used. Liquid A and liquid B were mixed in a volume ratio such that liquid A: liquid B = 6.5: 3.5, and this was used as the mobile phase.
(3) Measurement conditions Column used: GH-C18 (4 mm ID. X 150 mm) (manufactured by Hitachi High-Technologies Corporation)
Mobile phase flow rate: 1 ml / min
Sample injection volume: 1 μl
Column temperature: 40 ° C
Detection wavelength: 211 nm

Catalyst Preparation Example 1 (Vanadium complex-encapsulated zeolite catalyst)
3 g of HY type zeolite (manufactured by ZEOLYST INTERNATIONAL, trade name “CBV 600”) was added to about 0.05 mol / l vanadium oxysulfate aqueous solution and stirred at 80 ° C. for 48 hours under reflux conditions. The precipitate was collected by filtration from the stirred solution, washed with the filtrate, and then dried at 120 ° C. for 24 hours to obtain vanadium-containing zeolite.
2 g of the obtained vanadium-encapsulated zeolite and 1 g of 2-pyrazinecarboxylic acid were added to 50 ml to 100 ml of ethanol and stirred at 65 ° C. for 12 hours under reflux conditions. The precipitate was collected from the stirred solution by filtration, and the filtrate was washed, then added to 50 ml of methanol, and stirred at 60 ° C. for 2 hours under reflux conditions. The precipitate is collected by filtration from the stirred solution, and the filtrate is washed and then dried at 100 ° C. for 24 hours to be vanadium complex-encapsulated zeolite catalyst (hereinafter referred to as [V (H ₆ C ₁₀ N ₄ O ₄ )]-Y. )

Catalyst Preparation Example 2 (Vanadium supported zeolite catalyst)
1.0 g of HY type zeolite (manufactured by ZEOLYST INTERNIONAL, trade name “CBV 600”) was immersed in 50 ml of 0.02 mol / l vanadium oxysulfate aqueous solution and evaporated to dryness. The residue was dried at 120 ° C. for 24 hours to obtain a vanadium-supported zeolite catalyst (hereinafter referred to as V / HY (imp)).

Catalyst Preparation Example 3 (Vanadium supported inorganic oxide catalyst)
A solution prepared by mixing 0.1 mol of L-alanine and 0.2 mol of sodium acetate in 200 ml of distilled water and a solution of 0.1 mol of salicylaldehyde in 250 ml of ethanol were mixed. To this mixture, 80 ml of 1.06 mol / l vanadium (II) sulfate aqueous solution was added, mixed and stirred at room temperature for 24 hours, and then the precipitate was collected from the mixture by filtration. After washing the filtrate to obtain a vanadium complex _{(VH 11} C 9 NO ₅₎ by overnight standing in vacuo.
0.16 g of the obtained vanadium complex was dissolved in 50 ml of distilled water, and 3 g of SiO ₂ (manufactured by Fuji Silysia Ltd., “CALiACT (registered trademark) Q-10”) was immersed in this aqueous solution and evaporated to dryness. The residue was dried at 120 ° C. for 24 hours to obtain a vanadium-supported inorganic oxide catalyst (hereinafter, (V-SiO ₂ )).

Production and production example of phenol 1-1
A glass pressure-resistant batch reactor was used for the reaction, 0.1 g of vanadium complex-encapsulated zeolite catalyst ([V (H ₆ C ₁₀ N ₄ O ₄ )]-Y) as a catalyst, and 0.5 ml of benzene as a reaction substrate ( 5.6 mmol), 0.1369 g (0.4 mmol) of sucrose as a reducing agent, and 20 vol% acetic acid aqueous solution as a solvent were placed in a 5 ml reactor. And reaction was performed at 80 degreeC for 20 hours, stirring with 0.4 MPa oxygen pressurization. About the reaction liquid after progress for a predetermined time, the product was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 1.

Production Example 1-2
A used catalyst is filtered from the reaction solution after the reaction of Production Example 1-1, washed with acetone, dried at 120 ° C. for 24 hours, and used once (hereinafter referred to as [V (H ₆ C _{10 N 4 O 4)] - Y} -2nd) was obtained. In a pressure-resistant batch reactor made of glass, 0.071 g of [V (H ₆ C ₁₀ N ₄ O ₄ )]-Y-2nd as a catalyst, 0.5 ml (5.6 mmol) of benzene as a reaction substrate, and sucrose as a reducing agent Was added to a 5 ml reactor with 0.1369 g (0.4 mmol) of 20 vol% acetic acid aqueous solution as a solvent. And reaction was performed at 80 degreeC for 20 hours, stirring with 0.4 MPa oxygen pressurization. About the reaction liquid after progress for a predetermined time, the product was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 1.

Production Example 1-3
A used catalyst is filtered from the reaction solution after the reaction of Production Example 1-2, washed with acetone, dried at 120 ° C. for 24 hours, and used twice (hereinafter referred to as [V (H ₆ C ₁₀ N _{4 O 4)] - Y-} 3rd) was obtained. In a pressure-resistant batch reactor made of glass, 0.056 g of [V (H ₆ C ₁₀ N ₄ O ₄ )]-Y-3rd as a catalyst, 0.5 ml (5.6 mmol) of benzene as a reaction substrate, and sucrose as a reducing agent Was added to a 5 ml reactor with 0.1369 g (0.4 mmol) of 20 vol% acetic acid aqueous solution as a solvent. And reaction was performed at 80 degreeC for 20 hours, stirring with 0.4 MPa oxygen pressurization. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 1.

Production Example 2
The reaction was conducted in the same manner as in Production Examples 1-1 to 3 except that the catalyst was changed to 0.1 g of a vanadium-supported zeolite catalyst (V / HY (imp)). The reaction solution after each reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 1. The once-used catalyst was represented as V / HY (imp) -2nd, and the twice-used catalyst was represented as V / HY (imp) -3rd.

Production Example 3
The reaction was carried out in the same manner as in Production Example 1-1 except that the catalyst was changed to 0.1 g of a vanadium-supported inorganic oxide catalyst (V-SiO ₂ ). The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 1.

Production Example 4
The reaction was performed in the same manner as in Production Example 1-1, except that the catalyst was changed to 0.1 g of H-Y zeolite (manufactured by ZEOLYST INTERNATIONAL, trade name “CBV 600”). The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 1.

Production Example 5
The reaction was carried out in the same manner as in Production Example 1-1 except that the catalyst was changed to 0.1 g of SiO ₂ (trade name “CALiACT (registered trademark) Q-10” manufactured by Fuji Silysia Co., Ltd.). The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 1.

Production Example 6
The reaction was performed in the same manner as in Production Example 1-1 except that the catalyst was not used. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 1.

Production Example 7
The reaction was performed in the same manner as in Production Example 1-1 except that sucrose was not used. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 1.

As shown in Table 1, when Production Examples 1 to 7 were compared, vanadium complex-encapsulated zeolite catalyst ([V (H ₆ C ₁₀ N ₄ O ₄ )]-Y) was used as the catalyst, and sucrose was used as the reducing agent. The production example 1-1 used had the highest phenol yield. Furthermore, when the production examples 1-1 to 1-3 and 2-1 to 2-3 are compared, the vanadium complex-encapsulated zeolite catalyst is obtained by using TON (reused with vanadium in the catalyst) twice and three times. It can be seen that the rate of decrease in the value of the molar ratio of phenol is smaller than that of the vanadium-supported zeolite catalyst.

Production Example 8
The reaction was carried out in the same manner as in Production Example 1-1 except that the amount of benzene charged was changed to 0.3 ml (3.4 mmol). The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 2.

Production Example 9
The reaction was performed in the same manner as in Production Example 1-1 except that the amount of benzene charged was changed to 0.4 ml (4.5 mmol). The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 2.

Production Example 10
The reaction was performed in the same manner as in Production Example 1-1 except that the amount of benzene charged was changed to 0.6 ml (6.7 mmol). The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 2.

Production Example 11
The reaction was performed in the same manner as in Production Example 1-1 except that the amount of benzene charged was changed to 0.7 ml (7.9 mmol). The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 2.

Production Example 12
The reaction was performed in the same manner as in Production Example 1-1 except that the oxygen pressure was changed to 0.3 MPa. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 2.

Production Example 13
The reaction was performed in the same manner as in Production Example 1-1 except that the oxygen pressure was changed to 0.5 MPa. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 2.

Production Example 14
The reaction was performed in the same manner as in Production Example 1-1 except that the oxygen pressure was changed to 0.6 MPa. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 2.

Production Example 15
The reaction was performed in the same manner as in Production Example 1-1 except that the oxygen pressure was changed to 0.7 MPa. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 2.

Production Example 16
The reaction was performed in the same manner as in Production Example 1-1 except that the oxygen pressure was changed to 0.8 MPa. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 2.

Production Example 17
The reaction was performed in the same manner as in Production Example 1-1 except that the solvent was changed to 5 ml of 60 vol% acetic acid aqueous solution. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 2.

  As shown in Tables 1 and 2, when Production Examples 1-1 and 8 to 11 in which only the amount of benzene was changed were compared, Production Example 1-1 in which the amount of sucrose used relative to 1 mol of benzene was 0.07 mol was the most phenolic. The yield was high. In Production Examples 10 and 11 with a large amount of benzene used (the amount of sucrose used relative to 1 mol of benzene is 0.06 mol, 0.05 mol), the reason why the phenol yield did not increase is that benzene is excessive and is a reducing agent. This is thought to be due to the lack of sucrose. In addition, in Production Examples 8 and 9 where the amount of benzene used is small (the amount of sucrose used is 0.12 mol and 0.09 mol based on 1 mol of benzene), it is considered that the sequential oxidation of phenol proceeds and the phenol yield decreases.

  Comparing Production Examples 1-1 and 12-16 in which only the oxygen pressure was changed, Production Example 14 having an oxygen pressure of 0.6 MPa (amount of molecular oxygen used per 1 mol of benzene was 3.6 mol) had the highest phenol yield. Was expensive. In Production Examples 15 and 16 where the oxygen pressure was high, the phenol yield decreased because molecular oxygen became excessive, and hydroquinone, benzoquinone, catechol, and COx were generated by complete oxidation due to sequential oxidation of phenol. It is done.

Reference example 1
A glass pressure-resistant batch reactor was used for the reaction, 3.5 mg of V ₂ O ₅ (manufactured by Nacalai Tesque, trade name “vanadium pentoxide”) as a catalyst, and 0.5 ml (5.6 mmol) of benzene as a reaction substrate. Then, 2 mmol of zinc powder as a reducing agent and 60 vol% acetic acid aqueous solution as a solvent were placed in a 5 ml reactor. And it reacted at 80 degreeC for 24 hours, stirring under 0.4 MPa oxygen pressurization. About the reaction liquid after progress for a predetermined time, the product was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 3.

Reference example 2
The reaction was conducted in the same manner as in Reference Example 1 except that VO (acac) ₂ (trade name “Vanadium Oxyacetylacetonate” manufactured by Nacalai Tesque) was changed to 0.01 g. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 3.

Reference example 3
The reaction was performed in the same manner as in Reference Example 1 except that VCl ₃ (trade name “vanadium trichloride” manufactured by Nacalai Tesque, Inc.) was changed to 6.1 mg. The reaction solution after the reaction was quantified and qualitatively analyzed using a liquid phase chromatograph. The results are shown in Table 3.

Reference Examples 1 to 3 confirm how the yield of phenol changes when the valence of vanadium used as a catalyst is different. As shown in Table 3, Reference Example 2 using VO (acac) ₂ having vanadium valence of 4 had the highest phenol yield.

  According to the present invention, phenol can be produced economically and environmentally friendly.

Claims (6)

In the presence of a vanadium complex-encapsulated zeolite catalyst in which a vanadium complex is encapsulated in zeolite, a saccharide as a reducing agent, a solvent, and molecular oxygen,
A method for producing phenol, which comprises oxidizing benzene.   The vanadium complex constituting the vanadium complex-encapsulating zeolite catalyst is at least one selected from the group consisting of vanadium 2-pyrazinecarboxylate, vanadylacetylacetonate, vanadium 2-pyridinecarboxylate, and vanadium 2-quinolinecarboxylate. The method for producing phenol according to claim 1.   The method for producing phenol according to claim 1 or 2, wherein the zeolite constituting the vanadium complex-encapsulating zeolite catalyst is Y-type zeolite.   The method for producing phenol according to any one of claims 1 to 3, wherein the saccharide is at least one selected from the group consisting of glucose, fructose, and sucrose.   The manufacturing method of the phenol as described in any one of Claims 1-4 whose usage-amount of the said saccharides is 0.03 mol-0.15 mol with respect to 1 mol of benzene.   The method for producing phenol according to any one of claims 1 to 5, wherein the solvent is an aqueous acetic acid solution having a concentration of 10 vol% to 50 vol%.