JPH07238042A - Production of phenols - Google Patents

Abstract

PURPOSE:To obtain phenols which is useful as an intermediate raw material for synthetic resins and agrochemicals in a high yield by direct oxidation of an aromatic compound with a gas containing molecular oxygen and carbon monoxide through a simplified process. CONSTITUTION:In the presence of a catalyst which is formed by supporting a Pd compound and/or Rh compound and V compound on a carrier, for example, PdCl2 or VOCl2 on silica, an aromatic compound is oxidized with a gas containing molecular oxygen and carbon monoxide, preferably in a liquid phase at 100 to 200 deg.C at the normal to 50kg/cm<2>G pressure. In the catalyst, 0.005 to 0.5mmol of Pd compound and/or Rh compound is supported on 1g of the carrier, and the molar ratio of the V compound to the Pd compound and/or the Rh compound is preferably 1 to 100. This process has no problem on by- product of acetone in comparison with the conventional cumene process.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for producing phenols, and more particularly to a method for producing phenols by directly oxidizing an aromatic compound with a gas containing molecular oxygen and carbon monoxide. .

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Phenols such as phenol, bisphenol and alkylphenol are extremely important substances as intermediate raw materials for various chemical industrial products such as synthetic resins and agricultural chemicals, and in particular, demand for phenol is particularly great.

Such phenols have hitherto been generally produced by the cumene method. However, the cumene method involves a multi-step process such as an oxidation process and a decomposition process, and has a problem in terms of equipment cost.In addition, the reaction produces by-molar acetone in an equimolar amount with phenol, and there is an inherent problem in securing a user of this acetone. ing.

Therefore, it is desired that the phenols are produced by a process as simple as possible and with a small amount of by-products. As one of such methods, a method of directly oxidizing an aromatic compound such as benzene to obtain phenols has been proposed.

For example, Japanese Patent Laid-Open No. 3-261735 proposes a method of oxidizing benzene with an oxygen (O ₂ ) -containing gas in the presence of a palladium (Pd) type catalyst. Further, in JP-A-4-244039, in the presence of copper (Cu) ions and palladium (Pd),
A liquid-phase oxidation method has been proposed in which benzene is oxidized by molecular oxygen that may contain carbon monoxide (CO). Furthermore, in Japanese Patent Laid-Open No. 5-4935,
Noble metals of Group VIII of the Periodic Table and IIIa, IV of the Periodic Table
Phenols are produced by reacting an aromatic compound with an oxygen-containing gas and hydrogen gas in the presence of a catalyst containing a, Va, VIa, VIIa, IIb, IVb and Vb. A method has been proposed.

According to these methods, since phenols can be produced by directly oxidizing an aromatic compound, the process is simplified as compared with the cumene method, and acetone is not by-produced. There is.

However, the above-mentioned conventional direct oxidation method has a big problem that the yield of phenols is low, and it is desired to improve the activity of producing phenols. The inventors of the present invention have earnestly studied a method for producing phenols by such a direct oxidation method of an aromatic compound, and found that a catalyst in which a palladium compound and / or a rhodium compound and a vanadium compound are supported on a carrier is present. The present invention has been completed based on the finding that phenols can be obtained in a high yield by oxidizing a gas containing molecular oxygen and carbon monoxide below.

[0008]

An object of the present invention is to provide a method for producing phenols, which comprises a simplified process, is free from problems such as by-product of acetone, and can produce phenols in high yield. Is intended to provide.

[0009]

SUMMARY OF THE INVENTION The method for producing a phenol compound according to the present invention comprises: (i) a palladium compound and / or a rhodium compound; and (ii) a vanadium compound in the presence of a catalyst, It is characterized in that the compound is oxidized by a gas containing molecular oxygen and carbon monoxide.

The above (i) palladium compound and / or rhodium compound is 0.005 to 0.005 with respect to 1 g of the carrier.
It is preferably loaded in an amount of 5 mmol. this
(i) The palladium compound or rhodium compound is preferably an inorganic or organic salt of palladium or rhodium, and is preferably a chloride of palladium or rhodium.

The vanadium compound (ii) is preferably supported in an amount of 1 to 100 in molar ratio with respect to the palladium compound and / or the rhodium compound (i).
The (ii) vanadium compound is preferably a divalent to tetravalent vanadium chloride or a divalent to tetravalent vanadium oxychloride.

Further, the above carrier is preferably at least one selected from the group consisting of silica, alumina, silica-alumina, niobium oxide, titanium oxide and zirconium oxide.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The method for producing phenols according to the present invention will be described below. First, the catalyst used in the present invention will be described.

[0014] As used catalysts present invention the catalyst is formed by supporting (i) the palladium compound and / or rhodium compound, and (ii) a vanadium compound, a carrier.

Specific examples of the (i) palladium compound or rhodium compound include inorganic salts or organic salts of palladium or rhodium. More specifically, the palladium compound is palladium chloride (P
dCl _2), fluoride palladium (Pdf _2), palladium bromide (PdBr _2), chlorides such as iodide palladium (PdI _2), palladium sulfate (PdSO _4), palladium nitrate _{(Pd (NO 3) 2)} , Palladium sulfide (Pd
S), palladium acetate, palladium hydroxide, tetraamminedichloropalladium [Pd (NH ₃ ) ₄ ] Cl ₂ · H ₂
Inorganic complexes such as O, Pd (PPh ₃ ) ₄ , PdCl ₂ (P
Ph ₃ ) ₂ , [(CH ₃ ) ₂ PdPPh ₃ ], [Pd (PP
h ₃ ) ₂ (olefin)] and other palladium phosphine complexes, heteropolyacid salts, [Pd (CO) Cl ₂ ] ₂ , [P
palladium carbonyl complex such as d (CO) ₂ Cl] ₂ , palladium diisonitrile complex, [CH ₃ PdOC
OCH ₃ ] and other palladium alkyl complexes, [Pd (η ₃
-C ₃ H ₅ ) ₂ ] and other palladium allyl complexes, palladium aryl complexes, palladium acetylacetonates and other palladium acyl complexes, and the like.

Examples of the rhodium compound include compounds in which palladium in the above compound is replaced with rhodium. Among these, chlorides of palladium or rhodium, inorganic salts such as sulfates, nitrates and heteropolyacid salts, and organic salts such as acetates are preferable, and chlorides such as palladium chloride and rhodium chloride are particularly preferably used.

In the present invention, the palladium compound or the rhodium compound may be used alone, or the palladium compound and the rhodium compound may be used in combination. Examples of the (ii) vanadium compound used in the present invention include divalent to tetravalent vanadium compounds, such as vanadium chloride, vanadyl chloride, vanadium sulfate, vanadyl sulfate,
Examples thereof include vanadium nitrate and vanadyl nitrate.

Of these, chlorides or oxychlorides of 2 to 4 valent vanadium are preferably used. As the carrier, compounds known as catalyst carriers such as silica, alumina, silica-alumina, niobium oxide, titanium oxide and zirconium oxide can be widely used. These can also be used in combination. Such a carrier is 10 to 500 m ² / g, preferably 100 to 400 m ²
It is desirable to have a specific surface area of / g.

Of these, silica is preferably used as the carrier. In the catalyst used in the present invention, the above-mentioned (i) palladium compound and / or rhodium compound is 0.005-0.5 mmol / g-carrier, preferably 0.01-0.3 mmol / g-. It is desirable that the carrier is supported in the amount of the carrier.

The vanadium compound (ii) is preferably supported on the carrier in a molar ratio of 1 to 100, preferably 5 to 80, based on the total amount of the (i) palladium compound and / or rhodium compound.

The catalyst as described above can be prepared by supporting the components (i) and (ii) on a carrier by a conventionally known method. For example, on the carrier, the catalyst component (i)
It can be prepared by a method of impregnating an aqueous solution of (ii) and (ii), more specifically, catalyst components (i) and (i
It can be prepared by dissolving i) in dilute hydrochloric acid or dilute sulfuric acid, immersing the carrier in the resulting solution to support the catalyst component on the carrier, and then drying and / or calcining the carrier. When the catalyst components (i) and (ii) are loaded on the carrier, the catalyst components (i) and (ii) may be loaded simultaneously or sequentially.

The catalyst as described above can produce phenols from aromatic compounds in high yield. In the catalyst thus prepared, the active ingredient (i) the palladium compound and / or the rhodium compound is highly dispersed on the carrier, and the active ingredient (ii) the vanadium compound is further present around it. Are thought to be dispersed. In general, when the loading amount (concentration) of the active ingredients (i) and (ii) is low, the active ingredient is highly dispersed but has few active sites and may exhibit sufficient catalytic activity. If not, on the other hand, when the amount of the active ingredient carried is large, the surface area of the active ingredient decreases due to the aggregation of the metal,
Apparent activity may decrease.

Oxidation Reaction In the present invention, an aromatic compound is oxidized with a gas containing molecular oxygen and carbon monoxide in the presence of the above catalyst.

Examples of the aromatic compound used in the oxidation reaction in the present invention include monocyclic aromatic compounds such as benzene, toluene, xylene and anisole, and non-condensed polycyclic aromatic compounds such as diphenyl, diphenylmethane and diphenyl ether. Examples thereof include compounds, condensed polycyclic aromatic compounds such as naphthalene, and indene.

Of these, benzene is particularly preferably used. Examples of the molecular oxygen used in the reaction include oxygen gas and oxygen-containing gas such as air.

As carbon monoxide (CO), pure carbon monoxide is preferable, but carbon monoxide-containing gas obtained from water gas, generator gas, coke oven gas or the like can also be used.

These molecular oxygen and carbon monoxide can be diluted with an inert gas such as nitrogen, helium, argon, carbon dioxide and the like. Molecular oxygen is 0.005 to 1 mol of aromatic compound in the reaction system.
It is preferably present in an amount of 0.5 mol.

The ratio of carbon monoxide to oxygen used is not particularly limited, but is usually 0.1 to 1 in terms of CO / O ₂ molar ratio.
0, and preferably from 0.1 to 5 from an economical point of view.
Molecular oxygen and carbon monoxide may be premixed and fed to the reactor or may be fed separately.

The above-mentioned oxidation reaction can be carried out in a liquid phase or a gas phase, but is preferably carried out in a liquid phase. When this oxidation reaction is carried out in the liquid phase, the aromatic compound itself as a raw material may be used as a solvent, and other solvent may be used as necessary. As such a solvent,
Saturated hydrocarbons such as pentane and cyclohexane, nitriles such as acetonitrile, ethers such as methyl ether and ethyl ether, amides such as acetamide and N, N-dimethylacetamide, organic acids such as formic acid, acetic acid and propionic acid. The organic solvent, and further water. These may be used in combination of two or more.

When the above-mentioned oxidation reaction is carried out in the liquid phase, it is usually carried out under acidic conditions such as acetic acid, hydrochloric acid, phosphoric acid,
It can be carried out in the presence of an acid such as sulfuric acid, nitric acid or formic acid. The oxidation reaction can also be carried out in the presence of 1,10-phenanthroline.

The 1,10-phenanthroline can be used in an amount of 0.001 to 0.1 mol based on 1 mol of the aromatic compound. In the present invention, the oxidation reaction has a reaction temperature of 80.
To 250 DEG ° C. preferably 100 to 200 ° C., and the pressure it is desirable that preferably normal pressure to 100 kg / cm ² G takes place at normal pressure ~50kg / cm ² G.

The above reaction can be carried out in a batch system, a continuous system,
Any method such as a semi-continuous method may be used.

[0033]

According to the method for producing phenols of the present invention, it is possible to directly oxidize an aromatic compound to obtain phenols in a high yield.

[0034]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples.

[0035]

Example 1 1 mmol of palladium chloride (PdCl ₂ ) and 50 mmol of vanadium oxychloride (VOCl ₂ ) were dissolved in 50 ml of 1N hydrochloric acid solution, and silica (FUJI-DAVISON, specific surface area 200 m ² / g) was added to this solution. ) 20 g was added. The solution was evaporated to dryness on a hot water bath, and the obtained solid was vacuum dried at room temperature for 2 hours to obtain a catalyst.

In a high-pressure batch reactor equipped with a reflux condenser, 80 ml of benzene as a reaction solution and 20 ml of acetic acid.
And were charged and mixed, 3 g of the catalyst prepared as described above was added, and the pressure was 30 kg with an inert gas (nitrogen gas).
After pressurizing to / cm ² G, carbon monoxide (CO) and oxygen (O ₂ ) were introduced at a rate of 50 cc / min, and the reaction was carried out at a reaction temperature of 130 ° C. for 1 hour.

The reaction product thus obtained was analyzed by gas chromatography. The results are shown in Table 1.

[0038]

Example 2 A phenol synthesis reaction was carried out in the same manner as in Example 1 except that vanadium oxychloride was replaced with vanadium chloride (VCl ₃ ). The results are shown in Table 1.

[0039]

Example 3 A phenol synthesis reaction was carried out in the same manner as in Example 1 except that rhodium chloride (RhCl ₂ ) was used instead of palladium chloride. The results are shown in Table 1.

[0040]

Example 4 A phenol synthesis reaction was carried out in the same manner as in Example 3 except that vanadium oxychloride was replaced with vanadium chloride (VCl ₃ ). The results are shown in Table 1.

[0041]

Comparative Example 1 A phenol synthesis reaction was carried out in the same manner as in Example 1 except that vanadium oxychloride was not added. The results are shown in Table 1.

[0042]

Comparative Example 2 A phenol synthesis reaction was carried out in the same manner as in Example 3 except that vanadium oxychloride was not added. The results are shown in Table 1.

[0043]

[Table 1]

[0044]

Example 5 A phenol synthesis reaction was performed in the same manner as in Example 1 except that titanium oxide was used instead of silica. The results are shown in Table 2.

[0045]

Example 6 A phenol synthesis reaction was performed in the same manner as in Example 1 except that silica was changed to alumina. The results are shown in Table 2.

[0046]

Example 7 A phenol synthesis reaction was carried out in the same manner as in Example 1 except that zirconium oxide was used instead of silica. The results are shown in Table 2.

[0047]

[Table 2]

[0048]

EXAMPLE 8 1 mmol of palladium chloride, 1 mmol of rhodium chloride and 10 mmol of vanadium oxychloride were dissolved in 50 ml of 1N hydrochloric acid solution, and silica (FUJI
-DAVISON) 20g was added. After evaporating to dryness on a hot water bath, 2
The catalyst was prepared by vacuum drying at room temperature for 1 hour.

A phenol synthesis reaction was carried out in the same manner as in Example 1 except that the catalyst thus obtained was used. The results are shown in Table 3.

[0050]

Example 9 A phenol synthesis reaction was carried out in the same manner as in Example 8 except that vanadium oxychloride was used in an amount of 30 mmol. The results are shown in Table 3.

[0051]

Example 10 A phenol synthesis reaction was carried out in the same manner as in Example 8 except that vanadium oxychloride was used in an amount of 60 mmol. The results are shown in Table 3.

[0052]

Comparative Example 3 A phenol synthesis reaction was carried out in the same manner as in Example 8 except that vanadium oxychloride was not used. The results are shown in Table 3.

[0053]

[Table 3]

[0054]

Comparative Example 4 A phenol synthesis reaction was carried out in the same manner as in Example 1 except that H ₂ was used instead of CO.

The phenol production activity was 0.1 mmol / g-cat · h.

Claims (7)

[Claims] 1. An aromatic compound, molecular oxygen and carbon monoxide in the presence of a catalyst comprising (i) a palladium compound and / or a rhodium compound and (ii) a vanadium compound supported on a carrier. A method for producing phenols, characterized by being oxidized by a gas containing. 2. The phenol according to claim 1, wherein (i) the palladium compound and / or the rhodium compound is supported in an amount of 0.005 to 0.5 mmol per 1 g of the carrier. Manufacturing method. 3. The phenol according to claim 1, wherein (ii) the vanadium compound is supported on the carrier in an amount of 1 to 100 in a molar ratio to the (i) palladium compound and / or rhodium compound. Manufacturing method. 4. The method for producing phenols according to claim 1, wherein (i) the palladium compound or rhodium compound is an inorganic or organic salt of palladium or rhodium. 5. The method for producing phenols according to claim 4, wherein the inorganic salt of palladium or rhodium is a chloride of palladium or rhodium. 6. The method for producing phenols according to claim 1, wherein (ii) the vanadium compound is a chloride of 2 to 4 valent vanadium or an oxychloride of 2 to 4 valent vanadium. 7. The production of phenols according to claim 1, wherein the carrier is at least one selected from the group consisting of silica, alumina, silica-alumina, niobium oxide, titanium oxide and zirconium oxide. Method.