Preparation method of p-hydroxyanisole and o-hydroxyanisole

Abstract

The invention belongs to the technical field of hydroxyanisole synthesis, and provides a preparation method of p-hydroxyanisole and o-hydroxyanisole. According to the preparation method, anisole and hydrogen peroxide are subjected to a hydroxylation reaction in an organic solvent containing carboxylic acid in the presence of a catalyst, and the catalyst is a metal phthalocyanine complex / titanium silicalite molecular sieve composite catalyst. According to the invention, p-hydroxyanisole and o-hydroxyanisole are prepared through hydroxylation reaction of anisole, and low-carbon-chain carboxylic acid is added, so that the conversion rate of anisole is increased; in the metal phthalocyanine complex / titanium silicalite molecular sieve composite catalyst, metal phthalocyanine is uniformly distributed in a pore channel of a titanium silicalite molecular sieve in a complex form, the metal phthalocyanine modified titanium silicalite molecular sieve is loaded with active components containing alkaline earth metal oxide and alkali metal chloride through an equivalent-volume impregnation method, and the metal phthalocyanine modified titanium silicalite molecular sieve and the active components have a synergistic effect; the catalytic activity of the composite catalyst and the selectivity of hydroxylation reaction of a target product can be improved at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydroxyanisole synthesis, and particularly relates to a preparation method of p-hydroxyanisole and o-hydroxyanisole. BACKGROUND

[0002] P-hydroxyanisole is a common fine chemical product, which can be used as a polymerization inhibitor, an antioxidant and a plasticizer, and is also an important intermediate in the production of pharmaceuticals, spices and pesticides. At present, there are mainly two paths for synthesizing p-hydroxyanisole. One is to use phenol as a raw material and synthesize by methylation. Commonly used methylating agents include methanol, dimethyl carbonate and dimethyl sulfate. Among them, dimethyl sulfate itself is a toxic product, is expensive, and has harsh reaction conditions. In addition, due to the chemical activity of dimethyl sulfate, many side reactions occur, tar-like by-products are produced, and the selectivity of hydroxyanisole in the product is low. Although methanol is used as a methylating agent, the use of dimethyl sulfate is avoided, but benzene is still used as a solvent, which still has great toxicity and is expensive. The other is to use methoxyaniline as a raw material and synthesize by diazotization reaction, which needs to go through two steps of diazotization and hydrolysis. This process has large sewage discharge and serious pollution, and the hydrolysis process needs to be carried out under high temperature and high acid conditions, which has strict requirements on the operating environment and low yield.

[0003] Using anisole as a raw material, p-hydroxyanisole and o-hydroxyanisole are produced by hydroxylation reaction under the condition of a catalyst, which is a new synthesis path, greatly reduces the reaction steps, has simple operation, mild reaction conditions, does not produce harmful by-products, and has broad application prospects. In this method, the selection and application of the catalyst are the key. Patent CN113731400A discloses that K7[MnV 13 O 38 ]·18H2O is used as a catalyst for the synthesis of hydroxyanisole by anisole hydroxylation reaction, and the yield of the hydroxylation product is 73-76%, and the selectivity is 96-98%. However, the preparation process of the catalyst is complex and has serious pollution, which does not meet the green and environmental protection concept. Patent CN119038572A discloses the application of TS-1 molecular sieve in anisole hydroxylation reaction, and TS-1 molecular sieve can effectively improve the utilization rate of hydrogen peroxide and promote the anisole hydroxylation reaction. Patent CN115490579A discloses that anisole and hydrogen peroxide are used as raw materials, and copper and cadmium supported on alkali-modified microspherical titanium silicalite molecular sieve are used as a catalyst to prepare hydroxyanisole. The modified titanium silicalite molecular sieve has high application prospects, but its catalytic activity and stability still have great challenges.

[0004] Therefore, it is necessary to study a new method for preparing hydroxyanisole from anisole as a raw material, so as to obtain higher conversion rate and hydroxyanisole yield. SUMMARY

[0005] The present application aims at providing a preparation method of p-hydroxyanisole and o-hydroxyanisole to overcome the defects of the prior art.

[0006] To achieve the above-mentioned purposes, the present application provides the following technical solutions. The present application provides a preparation method of p-hydroxyanisole and o-hydroxyanisole, which comprises the following steps: in the presence of a catalyst, anisole and hydrogen peroxide are subjected to a hydroxylation reaction. The hydroxylation reaction is carried out in an organic solvent containing a carboxylic acid. The catalyst is a metal phthalocyanine complex / titanium silicalite composite catalyst.

[0007] Preferably, the carboxylic acid is a carboxylic acid with a carbon atom number of 1-5. The molar ratio of the anisole, hydrogen peroxide, carboxylic acid and organic solvent is 1:1-4:1-4:1-10. The mass of the metal phthalocyanine complex / titanium silicalite composite catalyst is 0.5-3% of the mass of the anisole.

[0008] Preferably, the preparation method of the metal phthalocyanine complex / titanium silicalite composite catalyst comprises the following steps: 1) Dissolving a water-soluble metal phthalocyanine in water, adding cetyltrimethylammonium bromide to obtain a metal phthalocyanine micellar solution; Mixing a sodium silicate solution, a titanium source and a complexing agent, and adjusting the pH value to obtain a mixed solution; 2) Adding the metal phthalocyanine micellar solution to the mixed solution, and sequentially performing pre-crystallization and hydrothermal crystallization to obtain a metal phthalocyanine complex / titanium silicalite; 3) Loading an active component to the metal phthalocyanine complex / titanium silicalite to obtain a metal phthalocyanine complex / titanium silicalite composite catalyst.

[0009] Preferably, the water-soluble metal phthalocyanine is a metal phthalocyanine tetrasulfonic acid or a metal phthalocyanine tetracarboxylic acid. The metal element in the water-soluble metal phthalocyanine comprises iron or nickel. The active component comprises an alkaline earth metal oxide and an alkali metal chloride.

[0010] Preferably, the titanium source comprises one or more of n-butyl titanate, tetraethyl titanate and titanium tetrachloride, and the complexing agent comprises citric acid and / or oxalic acid. In step 1), the pH value of the mixed solution is 10-11.

[0011] Preferably, in step 1), the molar ratio of the sodium silicate and the titanium source in the mixed solution is 1:0.02-0.05, and the molar ratio of the titanium source and the complexing agent is 1:1-2. The molar ratio of the cetyltrimethylammonium bromide in the metal phthalocyanine micellar solution and the sodium silicate in the mixed solution is 0.3-0.6:1; The molar ratio of the water-soluble metal phthalocyanine in the metal phthalocyanine micellar solution and the sodium silicate in the mixed solution is 1:100-150.

[0012] Preferably, the mass-volume ratio of the water-soluble metal phthalocyanine and water in step 1) is 0.1-1 g:20 mL, and the mass fraction of the sodium silicate solution is 50-70%.

[0013] Preferably, the temperature of the pre-crystallization in step 2) is 80-100℃, and the pre-crystallization time is 10-16 h; The temperature of the hydrothermal crystallization is 120-150℃, and the hydrothermal crystallization time is 24-48 h.

[0014] Preferably, the loading in step 3) adopts an equal-volume impregnation method, the loading amount of the alkaline earth metal oxide is 1-5%, and the loading amount of the alkali metal chloride is 1-5%.

[0015] Preferably, the temperature of the hydroxylation reaction is 50-80℃, and the hydroxylation reaction time is 2-10 h.

[0016] The present application has the following beneficial effects: 1) The present application uses anisole as a raw material to prepare p-hydroxyanisole and o-hydroxyanisole through a hydroxylation reaction. The steps are simple, the conditions are mild, no harmful by-products are produced, and there is no environmental pollution hazard, which conforms to the green and environmental protection concept.

[0017] 2) The present application improves the conversion rate of the anisole hydroxylation reaction by adding a low-carbon chain carboxylic acid to the reaction system. In the metal phthalocyanine complex / titanium silicalite composite catalyst, on the one hand, the metal phthalocyanine is assembled in the titanium silicalite to uniformly distribute in the pore channel of the titanium silicalite in the form of a complex, and on the other hand, the titanium silicalite modified by the metal phthalocyanine is loaded with active components containing alkaline earth metal oxides and alkali metal chlorides through an equal-volume impregnation method. The metal phthalocyanine complex and the loaded active components have a synergistic effect, which can simultaneously improve the catalytic activity of the composite catalyst and the selectivity of the target product hydroxylation reaction. The metal phthalocyanine complex / titanium silicalite composite catalyst is prepared using water-soluble metal phthalocyanine as a raw material, and has the characteristics of both heterogeneous catalysts and homogeneous catalysts, and is more excellent than the traditional TS-1 molecular sieve heterogeneous catalyst in terms of catalytic effect.

[0018] 3) The preparation method of the present application can make the conversion rate of anisole reach more than 55%, and the selectivity of phenol in the product is as low as 1.5% or less, which significantly improves the yield of p-hydroxyanisole and o-hydroxyanisole. DETAILED DESCRIPTION

[0019] The application provides a preparation method of p-hydroxyanisole and o-hydroxyanisole, which comprises the following steps: performing a hydroxylation reaction on anisole and hydrogen peroxide in the presence of a catalyst. The hydroxylation reaction is performed in an organic solvent containing a carboxylic acid. The catalyst is a metal phthalocyanine complex / titanium silicalite composite catalyst.

[0020] In the application, the carboxylic acid is preferably a carboxylic acid with a carbon atom number of 1-5, further preferably a carboxylic acid with a carbon atom number of 2-4, and more preferably a carboxylic acid with a carbon atom number of 3. The molar ratio of the anisole, hydrogen peroxide, carboxylic acid and organic solvent is preferably 1:1-4:1-4:1-10, further preferably 1:1.5-3:1.5-3:3-8, and more preferably 1:2-2.5:2-2.5:5-7. The mass of the metal phthalocyanine complex / titanium silicalite composite catalyst is preferably 0.5-3% of the mass of the anisole, further preferably 1-2.5%, and more preferably 1.5-2%.

[0021] In the application, the organic solvent preferably comprises one or more of methanol, acetone and acetonitrile.

[0022] In the application, the preparation method of the metal phthalocyanine complex / titanium silicalite composite catalyst preferably comprises the following steps: 1) dissolving a water-soluble metal phthalocyanine in water, adding cetyltrimethylammonium bromide to obtain a metal phthalocyanine micellar solution; mixing a sodium silicate solution, a titanium source and a complexing agent, and adjusting the pH value to obtain a mixed solution; 2) adding the metal phthalocyanine micellar solution to the mixed solution, and sequentially performing pre-crystallization and hydrothermal crystallization to obtain a metal phthalocyanine complex / titanium silicalite; 3) loading an active component on the metal phthalocyanine complex / titanium silicalite to obtain the metal phthalocyanine complex / titanium silicalite composite catalyst.

[0023] In the application, the water-soluble metal phthalocyanine is preferably a metal phthalocyanine tetrasulfonate or a metal phthalocyanine tetracarboxylate; The metal element in the water-soluble metal phthalocyanine preferably comprises iron or nickel; The active component preferably comprises an alkaline earth metal oxide and an alkali metal chloride.

[0024] In the application, the titanium source preferably comprises one or more of n-butyl titanate, tetraethyl titanate and titanium tetrachloride, and the complexing agent preferably comprises citric acid and / or oxalic acid. In step 1), the pH value of the mixed solution is preferably 10-11, and further preferably 10.5.

[0025] In the present application, the reagent for adjusting pH value is preferably ammonia water, and the mass fraction of ammonia water is preferably 25-35%, further preferably 28-32%, and more preferably 30%.

[0026] In the present application, the molar ratio of sodium silicate to titanium source in the mixed solution in step 1) is preferably 1:0.02-0.05, further preferably 1:0.03-0.04, and more preferably 1:0.035; and the molar ratio of the titanium source to the complexing agent is preferably 1:1-2, further preferably 1:1.2-1.8, and more preferably 1:1.5. The molar ratio of cetyltrimethylammonium bromide in the metal phthalocyanine micellar solution to sodium silicate in the mixed solution is preferably 0.3-0.6:1, further preferably 0.4-0.5:1, and more preferably 0.45:1. The molar ratio of water-soluble metal phthalocyanine in the metal phthalocyanine micellar solution to sodium silicate in the mixed solution is preferably 1:100-150, further preferably 1:110-140, and more preferably 1:120-130.

[0027] In the present application, the mass-volume ratio of water-soluble metal phthalocyanine to water in step 1) is preferably 0.1-1 g:20 mL, further preferably 0.3-0.8 g:20 mL, and more preferably 0.5-0.6 g:20 mL; and the mass fraction of sodium silicate solution is preferably 50-70%, further preferably 55-65%, and more preferably 60%.

[0028] In the present application, the temperature of pre-crystallization in step 2) is preferably 80-100℃, further preferably 85-95℃, and more preferably 90℃; and the time of pre-crystallization is preferably 10-16 h, further preferably 12-15 h, and more preferably 13-14 h. The temperature of hydrothermal crystallization is preferably 120-150℃, further preferably 130-140℃, and more preferably 135℃; and the time of hydrothermal crystallization is preferably 24-48 h, further preferably 30-42 h, and more preferably 36 h.

[0029] In the present application, the loading in step 3) preferably adopts an equal-volume impregnation method, the loading amount of alkaline earth metal oxide is preferably 1-5%, further preferably 2-4%, and more preferably 3%; and the loading amount of alkali metal chloride is preferably 1-5%, further preferably 2-4%, and more preferably 3%.

[0030] In the present application, the steps of the equal-volume impregnation method preferably comprise: ①impregnating the metal phthalocyanine complex / titanium silicalite in an alkaline earth metal salt solution, and sequentially drying and calcining after impregnation to obtain an intermediate molecular sieve; ②impregnating the intermediate molecular sieve in an alkali metal salt solution, and sequentially drying and calcining after the impregnation is completed.

[0031] In the present application, the alkali earth metal salt solution preferably comprises one or more of a nitrate solution of alkali earth metal, a chloride solution of alkali earth metal and a sulfate solution of alkali earth metal, and the alkali metal salt solution is preferably a chloride solution of alkali metal.

[0032] In the present application, the alkali earth metal in the alkali earth metal salt solution preferably comprises one or more of magnesium, calcium and strontium, and the alkali metal in the alkali metal salt solution preferably comprises one or more of sodium, potassium and cesium.

[0033] In the present application, the impregnation time in step ① is preferably 4-10h, further preferably 5-9h, and more preferably 6-8h, and the impregnation time in step ② is preferably 2-6h, further preferably 3-5h, and more preferably 4h.

[0034] In the present application, the drying temperature in step ① and step ② is independently preferably 80-100℃, further preferably 85-95℃, and more preferably 90℃, and the drying time is independently preferably 4-8h, further preferably 5-7h, and more preferably 6h. The calcination temperature in step ① and step ② is independently preferably 450-550℃, further preferably 480-520℃, and more preferably 500℃, and the calcination time is independently preferably 10-16h, further preferably 12-14h, and more preferably 13h.

[0035] In the present application, the hydroxylation temperature is preferably 50-80℃, further preferably 55-70℃, and more preferably 60-65℃, and the hydroxylation time is preferably 2-10h, further preferably 4-8h, and more preferably 6h.

[0036] The technical solutions provided by the present application will be described in detail below in combination with examples, but they should not be understood as limiting the scope of protection of the present application.

[0037] Example 1

[0038] The metal phthalocyanine micellar solution was prepared by dissolving 0.1 g of iron tetrakis sulfonate phthalocyanine in 20 mL of deionized water, and then adding cetyltrimethylammonium bromide and shaking until completely dissolved. The n-butyl titanate, citric acid and 50% sodium silicate aqueous solution were added to the mixture, and the pH value was adjusted to 10 using 30% ammonia water to obtain a mixed solution. The molar ratio of sodium silicate to n-butyl titanate in the mixed solution was 1:0.05, and the molar ratio of n-butyl titanate to citric acid was 1:1. The metal phthalocyanine micellar solution was added to the mixed solution, and the mixture was uniformly mixed to obtain a reaction solution. The molar ratio of cetyltrimethylammonium bromide to sodium silicate in the reaction solution was 0.45:1, and the molar ratio of iron tetrakis sulfonate phthalocyanine to sodium silicate was 1:150. The reaction solution was pre-crystallized at 90°C for 10 h, and then hydrothermally crystallized at 150°C for 36 h. After hydrothermal crystallization, the mixture was cooled to room temperature, washed with deionized water until the filtrate was colorless, and then dried at 80°C for 4 h to obtain the metal phthalocyanine complex / titanium silicate molecular sieve. At room temperature, the metal phthalocyanine complex / titanium silicate molecular sieve was impregnated in a mixed solution of magnesium nitrate and calcium nitrate (the molar ratio of calcium to magnesium was 1:1) by the equal volume impregnation method, impregnated for 6 h, then dried at 90°C for 4 h, and then calcined at 450°C for 12 h to obtain an intermediate molecular sieve with a total loading amount of magnesium oxide and calcium oxide of 2.5%. At room temperature, the intermediate molecular sieve was impregnated in a mixed solution of sodium chloride and cesium chloride (the molar ratio of sodium to cesium was 1:1) by the equal volume impregnation method, impregnated for 4 h, then dried at 80°C for 8 h, and then calcined at 550°C for 10 h to obtain the metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst, wherein the total loading amount of sodium chloride and cesium chloride was 1.5%.

[0039] The reaction system was prepared by uniformly mixing anisole, hydrogen peroxide (45% hydrogen peroxide by mass fraction) and methanol, and then adding acetic acid. The molar ratio of anisole, hydrogen peroxide, acetic acid and methanol in the reaction system was 1:2:4:5. The metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst was added to the reaction system, and the mass of the metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst was 2% of the mass of anisole. The reaction system was heated to 65°C and subjected to a hydroxylation reaction for 6 h. After the reaction was completed, the contents of anisole, phenol, p-hydroxyanisole and o-hydroxyanisole in the product were analyzed by high performance liquid chromatography, and the conversion rate of anisole, the selectivity of phenol and the p / o ratio (p-hydroxyanisole / o-hydroxyanisole) of hydroxyanisoles were calculated. The results are shown in Table 1.

[0040] Example 2

[0041] The metal phthalocyanine micellar solution was prepared by dissolving 0.5 g of nickel tetrasulfonated phthalocyanine in 20 mL of deionized water, and then adding cetyltrimethylammonium bromide and shaking until completely dissolved. The mixed solution was prepared by adding tetraethyl titanate and oxalic acid to a 60% by mass aqueous sodium silicate solution, and adjusting the pH to 10.5 using 30% by mass aqueous ammonia. The molar ratio of sodium silicate to tetraethyl titanate in the mixed solution was 1:0.035, and the molar ratio of tetraethyl titanate to oxalic acid was 1:2. The metal phthalocyanine micellar solution was added to the mixed solution, and mixed uniformly to obtain a reaction solution. The molar ratio of cetyltrimethylammonium bromide to sodium silicate in the reaction solution was 0.3:1, and the molar ratio of nickel tetrasulfonated phthalocyanine to sodium silicate was 1:130. The reaction solution was pre-crystallized at 80°C for 13 h, and then hydrothermally crystallized at 120°C for 24 h. After hydrothermal crystallization, the reaction solution was cooled to room temperature, washed with deionized water until the filtrate was colorless, and then dried at 80°C for 4 h to obtain the metal phthalocyanine complex / titanium silicate molecular sieve. The metal phthalocyanine complex / titanium silicate molecular sieve was impregnated in an equal volume of a mixed solution of magnesium nitrate and calcium nitrate (molar ratio of calcium to magnesium was 1:2) at room temperature, impregnated for 4 h, then dried at 100°C for 4 h, and then calcined at 500°C for 10 h to obtain an intermediate molecular sieve with a total loading of magnesium oxide and calcium oxide of 4.5%. The intermediate molecular sieve was impregnated in an equal volume of a mixed solution of sodium chloride and cesium chloride (molar ratio of sodium to cesium was 2:1) at room temperature, impregnated for 2 h, then dried at 90°C for 6 h, and then calcined at 500°C for 12 h to obtain the metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst with a total loading of sodium chloride and cesium chloride of 2.5%.

[0042] The reaction system was prepared by uniformly mixing anisole, hydrogen peroxide (45% by mass), and methanol, and then adding formic acid. The molar ratio of anisole, hydrogen peroxide, formic acid, and methanol in the reaction system was 1:1:2:1. The metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst was added to the reaction system, and the mass of the metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst was 0.5% of the mass of anisole. The reaction system was heated to 50°C and hydroxylation was performed for 10 h. After the reaction was completed, the contents of anisole, phenol, p-hydroxyanisole, and o-hydroxyanisole in the product were analyzed by high performance liquid chromatography, and the conversion of anisole, the selectivity of phenol, and the p / o ratio (p-hydroxyanisole / o-hydroxyanisole) of hydroxyanisoles were calculated. The results are shown in Table 1.

[0043] Example 3

[0044] The 1 g of tetracarboxylic acid group iron phthalocyanine was dissolved in 20 mL of deionized water, and then cetyltrimethylammonium bromide was added and shaken until completely dissolved to obtain a metal phthalocyanine micellar solution. Titanium tetrachloride, citric acid were added to a 60% by mass sodium silicate aqueous solution, and the pH value was adjusted to 11 using 30% by mass ammonia water to obtain a mixed solution. The molar ratio of sodium silicate to titanium tetrachloride in the mixed solution was 1:0.02, and the molar ratio of titanium tetrachloride to citric acid was 1:1.5. The metal phthalocyanine micellar solution was added to the mixed solution and mixed uniformly to obtain a reaction solution. The molar ratio of cetyltrimethylammonium bromide to sodium silicate in the reaction solution was 0.6:1, and the molar ratio of tetracarboxylic acid group iron phthalocyanine to sodium silicate was 1:100. The reaction solution was pre-crystallized at 100℃ for 16 h, and then hydrothermally crystallized at 135℃ for 48 h. After hydrothermal crystallization, the temperature was cooled to room temperature, and the filtrate was washed with deionized water until it was colorless, and then dried at 80℃ for 4 h to obtain a metal phthalocyanine complex / titanium silicate molecular sieve. At room temperature, the metal phthalocyanine complex / titanium silicate molecular sieve was impregnated in an equal volume of a mixed solution of strontium nitrate and calcium nitrate (the molar ratio of strontium to calcium was 1:1) using an equal volume impregnation method, impregnated for 8 h, then dried at 100℃ for 6 h, and then calcined at 500℃ for 16 h to obtain an intermediate molecular sieve with a total loading of strontium oxide and calcium oxide of 4.3%. At room temperature, the intermediate molecular sieve was impregnated in an equal volume of a mixed solution of potassium chloride and cesium chloride (the molar ratio of potassium to cesium was 2:1) using an equal volume impregnation method, impregnated for 5 h, then dried at 90℃ for 6 h, and then calcined at 450℃ for 14 h to obtain a metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst, wherein the total loading of potassium chloride and cesium chloride was 2.5%.

[0045] The anisole, hydrogen peroxide (the mass fraction of hydrogen peroxide was 45%), and methanol were mixed uniformly, and then butyric acid was added to obtain a reaction system. The molar ratio of anisole, hydrogen peroxide, butyric acid, and methanol in the reaction system was 1:4:1:10. The metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst was added to the reaction system, and the mass of the metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst was 3% of the mass of the anisole. The temperature was raised to 80℃, and the hydroxylation reaction was carried out for 2 h. After the reaction was completed, the contents of anisole, phenol, p-hydroxyanisole, and o-hydroxyanisole in the product were analyzed by high performance liquid chromatography, and the conversion rate of anisole, the selectivity of phenol, and the p / o ratio (p-hydroxyanisole / o-hydroxyanisole) of hydroxyanisoles were calculated. The results are shown in Table 1.

[0046] Comparative Example 1

[0047] The 0.1 g of iron tetrasulfonate phthalocyanine was dissolved in 20 mL of deionized water, and then cetyltrimethylammonium bromide was added and shaken until completely dissolved to obtain a metal phthalocyanine micellar solution. The n-butyl titanate, citric acid were added to a 50% by mass aqueous sodium silicate solution, and the pH value was adjusted to 10 using 30% by mass ammonia water to obtain a mixed solution. The molar ratio of sodium silicate to n-butyl titanate in the mixed solution was 1:0.05, and the molar ratio of n-butyl titanate to citric acid was 1:1. The metal phthalocyanine micellar solution was added to the mixed solution, and mixed uniformly to obtain a reaction solution. The molar ratio of cetyltrimethylammonium bromide to sodium silicate in the reaction solution was 0.45:1, and the molar ratio of iron tetrasulfonate phthalocyanine to sodium silicate was 1:150. The reaction solution was pre-crystallized at 90°C for 10 h, and then hydrothermally crystallized at 150°C for 36 h. After the hydrothermal crystallization was completed, the temperature was cooled to room temperature, and the filtrate was washed with deionized water until it was colorless, and then dried at 80°C for 4 h to obtain the metal phthalocyanine complex / titanium silicate molecular sieve.

[0048] The anisole, hydrogen peroxide (45% by mass of hydrogen peroxide), and methanol were mixed uniformly, and then acetic acid was added to obtain a reaction system. The molar ratio of anisole, hydrogen peroxide, acetic acid, and methanol in the reaction system was 1:2:4:5. The metal phthalocyanine complex / titanium silicate molecular sieve was added to the reaction system, and the mass of the metal phthalocyanine complex / titanium silicate molecular sieve was 2% of the mass of the anisole. The temperature was raised to 65°C, and the hydroxylation reaction was performed for 6 h. After the reaction was completed, the contents of anisole, phenol, p-hydroxyanisole, and o-hydroxyanisole in the product were analyzed by high performance liquid chromatography, and the anisole conversion rate, phenol selectivity, and p / o ratio (p-hydroxyanisole / o-hydroxyanisole) of the hydroxyanisoles were calculated. The results are shown in Table 1.

[0049] Comparative Example 2

[0050] At room temperature, the titanium silicate molecular sieve (TS-1) was impregnated in a mixed solution of magnesium nitrate and calcium nitrate (the molar ratio of calcium to magnesium was 1:1) by the equal volume impregnation method, impregnated for 6 h, then dried at 90°C for 4 h, and then calcined at 450°C for 12 h to obtain an intermediate molecular sieve with a total loading amount of magnesium oxide and calcium oxide of 2.8%. At room temperature, the intermediate molecular sieve was impregnated in a mixed solution of sodium chloride and cesium chloride (the molar ratio of sodium to cesium was 1:1) by the equal volume impregnation method, impregnated for 4 h, then dried at 80°C for 8 h, and then calcined at 550°C for 10 h to obtain a titanium silicate molecular sieve composite catalyst, wherein the total loading amount of sodium chloride and cesium chloride was 1.7%.

[0051] The anisole, hydrogen peroxide (mass fraction of hydrogen peroxide is 45%) and methanol were mixed uniformly to obtain a reaction system. The molar ratio of anisole, hydrogen peroxide, acetic acid and methanol in the reaction system was 1:2:4:5. The titanium silicalite molecular sieve composite catalyst was added into the reaction system, the mass of the titanium silicalite molecular sieve composite catalyst was 2% of the mass of anisole, and the hydroxylation reaction was carried out at 65 ℃ for 6 h. After the reaction was completed, the contents of anisole, phenol, p-hydroxyanisole and o-hydroxyanisole in the product were analyzed by high performance liquid chromatography, and the conversion rate of anisole, the selectivity of phenol and the p / o ratio (p-hydroxyanisole / o-hydroxyanisole) of hydroxyanisole were calculated. The results are shown in Table 1.

[0052] Comparative Example 3

[0053] The preparation method of the titanium silicalite molecular sieve composite catalyst was the same as that in Comparative Example 2.

[0054] The anisole, hydrogen peroxide (mass fraction of hydrogen peroxide is 45%) and methanol were mixed uniformly to obtain a reaction system. The molar ratio of anisole, hydrogen peroxide and methanol in the reaction system was 1:2:5. The titanium silicalite molecular sieve composite catalyst was added into the reaction system, the mass of the titanium silicalite molecular sieve composite catalyst was 2% of the mass of anisole, and the hydroxylation reaction was carried out at 65 ℃ for 6 h. After the reaction was completed, the contents of anisole, phenol, p-hydroxyanisole and o-hydroxyanisole in the product were analyzed by high performance liquid chromatography, and the conversion rate of anisole, the selectivity of phenol and the p / o ratio (p-hydroxyanisole / o-hydroxyanisole) of hydroxyanisole were calculated. The results are shown in Table 1.

[0055] Comparative Example 4

[0056] The metal phthalocyanine complex / titanium silicalite molecular sieve composite catalyst in Example 1 was replaced by titanium silicalite TS-1, and other conditions were the same as those in Example 1.

[0057] Table 1 Analysis results of products

[0058] From the above examples, the application provides a preparation method of p-hydroxyanisole and o-hydroxyanisole, by adding carboxylic acid in the reaction system, using metal phthalocyanine complex / titanium silical composite catalyst as the catalyst of hydroxylation reaction, which obviously improves the conversion rate of anisole hydroxylation, selectively carries out p-position and o-position hydroxylation of anisole, and effectively reduces the selectivity of by-product phenol. In the preparation method of the application, the conversion rate of anisole reaches more than 55%, and the selectivity of phenol is reduced to less than 1.5%, which is significantly better than the traditional titanium silical TS-1. The metal phthalocyanine complex / titanium silical composite catalyst of the application assembles metal phthalocyanine in titanium silical on one hand, and the metal phthalocyanine is uniformly distributed in the channel of titanium silical in the form of complex on the other hand, and through impregnation, it loads alkali earth metal oxide and alkali metal chloride on the surface as double active components, and the two modification methods synergistically improve the activity and selectivity of titanium silical in catalyzing anisole hydroxylation reaction.

[0059] The above only describes the preferred embodiments of the application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements should also be considered as the protection scope of the application.

Claims

1. A process for the preparation of p-hydroxyanisole, o-hydroxyanisole, characterized in that, In the presence of a catalyst, anisole and hydrogen peroxide are subjected to a hydroxylation reaction; The hydroxylation reaction is carried out in an organic solvent containing carboxylic acids: The catalyst is a metal phthalocyanine complex / titanium silicon molecular sieve composite catalyst.

2. The production method according to claim 1, characterized by, The carboxylic acid is a carboxylic acid with 1 to 5 carbon atoms; The molar ratio of the anisole, hydrogen peroxide, carboxylic acid, and organic solvent is 1:1~4:1~4:1~10; The mass of the metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst is 0.5~3% of the mass of anisole.

3. The production method according to claim 1 or 2, characterized by, The preparation method of the metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst includes the following steps: 1) Dissolve water-soluble metal phthalocyanine in water, add hexadecyltrimethylammonium bromide to obtain a metal phthalocyanine micelle solution; The sodium silicate solution, titanium source, and complexing agent were mixed and the pH value was adjusted to obtain a mixed solution. 2) Add the metal phthalocyanine micelle solution to the mixture, and perform pre-crystallization and hydrothermal crystallization in sequence to obtain metal phthalocyanine complex / titanium silicon molecular sieve; 3) Loading the active component onto the metal phthalocyanine complex / titanium silicate molecular sieve yields the metal phthalocyanine complex / titanium silicate molecular sieve composite catalyst.

4. The production method according to claim 3, characterized by, The water-soluble metal phthalocyanine is a tetrasulfonic acid metal phthalocyanine or a tetracarboxylic acid metal phthalocyanine; The metal element in the water-soluble metal phthalocyanine includes iron or nickel; The active components include alkaline earth metal oxides and alkali metal chlorides.

5. The preparation method according to claim 4, characterized in that, The titanium source comprises one or more of tetrabutyl titanate, tetraethyl titanate, and titanium tetrachloride, and the complexing agent comprises citric acid and / or oxalic acid. Step 1) The pH value of the mixture is 10~11.

6. The production method according to claim 4 or 5, characterized by, In step 1), the molar ratio of sodium silicate to titanium source in the mixture is 1:0.02~0.05, and the molar ratio of titanium source to complexing agent is 1:1~2. The molar ratio of hexadecyltrimethylammonium bromide in the metal phthalocyanine micelle solution to sodium silicate in the mixture is 0.3~0.6:1; The molar ratio of water-soluble metal phthalocyanine in the metal phthalocyanine micelle solution to sodium silicate in the mixture is 1:100~150.

7. The production method according to claim 6, wherein Step 1) The mass-to-volume ratio of the water-soluble metal phthalocyanine to water is 0.1~1g:20mL, and the mass fraction of the sodium silicate solution is 50~70%.

8. The production method according to claim 7, characterized by, Step 2) The pre-crystallization temperature is 80~100℃, and the pre-crystallization time is 10~16h; The hydrothermal crystallization temperature is 120~150℃, and the hydrothermal crystallization time is 24~48h.

9. The production method according to claim 7 or 8, characterized by, Step 3) The loading is carried out by equal volume impregnation method, and the loading amount of alkaline earth metal oxide is 1~5% and the loading amount of alkali metal chloride is 1~5%.

10. The method of claim 9, wherein, The hydroxylation reaction is carried out at a temperature of 50-80°C for 2-10 hours.

Images