A solid superacid catalyst, its preparation method and application

Abstract

The application belongs to the technical field of industrial catalysis, and particularly relates to a solid superacid catalyst and a preparation method and application thereof. The preparation method provided by the application comprises the following steps: twice adjusting the pH of a solution by using ammonia water to obtain a metal salt precursor, and acidifying the metal salt precursor to obtain the solid superacid catalyst. It can be seen that the raw material for preparing the catalyst is cheap and easy to obtain, and the preparation process is simple and green. The catalyst with a core-shell structure has excellent catalytic performance, and the conversion rate of reactants is still higher than 98% after the catalyst is repeatedly used for 5 times, so that the catalyst can be repeatedly used for many times and has the advantages of small energy consumption. When the catalyst is used for synthesizing bisphenol compounds, the conversion rate of reactants reaches 99.91%, and the product selectivity reaches 99.86%, so that the catalyst has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of industrial catalysis, and particularly relates to a solid superacid catalyst and a preparation method and application thereof. BACKGROUND

[0002] Bisphenol compounds are a class of organic compounds containing two or more phenolic groups. Due to their good optical properties and molding properties, excellent transparency, refractive index, and easy solubility, they are widely used in military, aerospace, electronics, and automotive industries. In modern polymer processing technology, bisphenol compounds are widely used in condensation reactions to prepare polycondensation products. Therefore, the research and development of new bisphenol compounds are of great significance for the development of new synthetic materials.

[0003] Bisphenol compounds are mainly synthesized by Friedel-Crafts alkylation condensation of phenol and ketone or aldehyde compounds under the action of an acidic catalyst. Due to the use of different catalysts, bisphenol compounds can be synthesized by various methods. Currently, the methods for synthesizing bisphenol compounds include concentrated sulfuric acid method, hydrogen chloride method, heteropoly acid method, ionic liquid method, modified ion exchange resin method, and molecular sieve method. Chinese patents CN 102795970B, CN 101735020A, and US 465458A use fluorenone and phenol as raw materials and concentrated sulfuric acid as a catalyst to synthesize bisphenol fluorene. This method has low reaction temperature, short reaction time, high yield, and simple operation. However, this method is prone to produce by-products, is difficult to stop the reaction in time, and causes serious equipment corrosion. In addition, there are problems such as poor product quality and high energy consumption. Chinese patents CN 1065654A and CN 112341317A use ketone and phenol as raw materials and hydrogen chloride as a catalyst to synthesize bisphenol A and bisphenol fluorene, respectively. This method can achieve a yield of 86.5% within 2h, but it has the problem of equipment corrosion, which does not meet the concept of green chemical industry. Chinese patents CN 1986509A and CN 1291959C use heteropoly acid method to synthesize bisphenol A and bisphenol fluorene, respectively. This method has the problems of poor product quality and high energy consumption. 12 O 40The solid catalyst used in the method can realize solid-liquid separation through general filtration after the reaction is completed, the filtrate is washed with a methanol aqueous solution, organic solvents are recrystallized, and white bisphenol fluorene crystals with high purity can be prepared. However, the reaction time of the method is relatively long, needs 6-15 hours, the product yield is low, the catalyst is expensive, and industrial production is difficult. Chinese patents CN 112574007B, CN 107698429B and CN 104876804B respectively disclose a method for synthesizing bisphenol A, bisphenol fluorene and bisphenol F by taking ketone, aldehyde and phenol as raw materials and taking ionic liquid as a catalyst. The yield of the method is as high as 98.5%, and the yield is as high as 99.6%. However, the preparation process of the ionic liquid is complex, the preparation raw materials are expensive, and the ionic liquid is difficult to separate from the reaction system and difficult to be recycled. Chinese patents CN 1295017C, CN 101003466A and CN 107176904B respectively disclose a method for synthesizing bisphenol A, bisphenol fluorene and bisphenol F by taking ketone, aldehyde and phenol as raw materials and taking cation exchange resin as a catalyst. The product selectivity of the method is only 91.5-95.5%, and more by-products are generated. Chinese patent CN 104086373A discloses a method for catalytically synthesizing bisphenol F by using flaky Al-SBA-15 mesoporous molecular sieve. The yield of the method is as high as 98.8%, but the repeated use performance of the catalyst is not clearly studied, and the molecular sieve has problems of expensive preparation raw materials and complex preparation process.

[0004] In summary, in the production process of bisphenol compounds, there are problems of great corrosion of liquid catalysts on production equipment, difficult recycling and the like; and there are problems of expensive preparation raw materials, complex preparation process and poor repeated use performance of solid catalysts. Therefore, it is urgent to develop a new solid catalyst which is pollution-free, has excellent catalytic performance and can be recycled for many times. SUMMARY

[0005] One of the purposes of the present application is to provide a preparation method of a solid superacid catalyst, which has simple preparation process, is green and environmentally friendly, and is suitable for preparing high-performance catalysts.

[0006] To achieve the above purposes, the present application adopts the following technical solutions:

[0007] A preparation method of a solid superacid catalyst, comprising the following steps:

[0008] (1) preparing a single-layer hydroxide M(OH) x : dissolving a metal M salt in deionized water, adjusting the pH of the solution with ammonia water to form a precipitate, stirring the precipitate overnight, drying to obtain a hydroxide M(OH) x , as a crystal nucleus;

[0009] (2) preparing a double-layer hydroxide M(OH) x @M(OH)x Precursor: dissolve metal M salt in deionized water, add M(OH) x of step (1), stir, adjust solution pH with ammonia, form precipitate, stir precipitate overnight, wash, filter, dry, and obtain double-layer hydroxide M(OH) x @M(OH) x Precursor, this process is for metal hydroxide M(OH) x Crystal nucleus is wrapped, and a shell structure is formed on the outer layer.

[0010] (3) Preparation of SO4 2- / M@M catalyst: use sulfuric acid to acidify M(OH) x @M(OH) x of step (2) precursor, after acidification, dry and calcine to obtain SO4 2- / M@M catalyst.

[0011] Further, the metal M salt in steps (1) and (2) is one of nitrate or chloride of Zr 4+ , Ti 4+ , Ce 3+ ; the concentration of the metal M salt solution in steps (1) and (2) is 0.1 g / mL.

[0012] Further, the mass ratio of the metal M salt to M(OH) x in step (2) is (1-5):1.

[0013] Further, the pH of the ammonia solution in steps (1) and (2) is adjusted to 9-11.

[0014] Further, the concentration of sulfuric acid in step (3) is 0.5-2 mol / L, and the mass of M(OH) x @M(OH) x precursor to the volume of sulfuric acid is 1 g:(10-20) mL; the calcination temperature is 500-650 DEG C, and the calcination time is 3-5 h.

[0015] Further, the drying temperature in steps (1), (2) and (3) is all 90-120 DEG C, and the drying time is all 10-14 h.

[0016] The second object of the present application is to provide a solid superacid catalyst, which has excellent catalytic performance and can be used repeatedly.

[0017] To achieve the above object, the present application adopts the following technical scheme:

[0018] A solid superacid catalyst is prepared by the above preparation method.

[0019] The third object of the present application is to provide an application of the solid superacid catalyst, and the product obtained by using the solid superacid catalyst of the present application has high selectivity and good product quality.

[0020] To achieve the above object, the present application adopts the following technical scheme:

[0021] An application of a solid superacid catalyst, and the application of the catalyst in synthesizing bisphenol compounds.

[0022] Further, the bisphenol compound is synthesized from phenol and a ketone or aldehyde compound under the action of the catalyst and the cocatalyst; the ketone compound is fluorenone or acetone, the aldehyde compound is formaldehyde, and the cocatalyst is β-mercaptopropionic acid; the temperature of the synthesis reaction is 100-130℃, and the time is 2-5h.

[0023] Further, in the reaction of synthesizing the bisphenol compound, the molar ratio of phenol to the ketone compound is (5-8) : 1, the molar ratio of phenol to the aldehyde compound is (25-30) : 1, the total mass ratio of the catalyst to phenol, the aldehyde or the ketone compound is 1 : (8-12), and the total mass ratio of the volume of β-mercaptopropionic acid to phenol, the aldehyde or the ketone compound is 1mL : (100-300) g.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] (1) The raw material of the present application is cheap and easy to obtain, and the preparation process is simple, green and environmentally friendly.

[0026] (2) The catalyst with core-shell structure prepared by the present application has excellent catalytic performance, and the conversion rate of the reactant is still higher than 98% after repeated use for 5 times, which has the advantages of multiple reuse and low energy consumption.

[0027] (3) When the catalyst prepared by the present application is used to synthesize bisphenol compounds, the conversion rate of the reactant reaches 99.91%, and the product selectivity reaches 99.86%, which has a broad application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The XRD pattern of the catalyst prepared in Example 1;

[0029] Figure 2 The FT-IR pattern of the catalyst prepared in Example 1;

[0030] Figure 3 The cyclic use performance pattern of the catalyst prepared in Example 1. DETAILED DESCRIPTION

[0031] The technical solutions of the present application are further explained in combination with specific examples, comparative examples, test examples and the accompanying drawings.

[0032] In the following examples, comparative examples and test examples, the raw materials and preparation methods used are conventional materials and techniques in the art unless otherwise specified.

[0033] I. Examples

[0034] Example 1

[0035] Example 1 provides a preparation method of a solid superacid catalyst, the specific process is as follows:

[0036] (1) Preparation of single-layer hydroxide Zr(OH)4: 10 g of Zr(NO3)4·5H2O was dissolved in 100 mL of deionized water, and ammonia water was added to adjust the pH of the solution to 10 to form a precipitate; the precipitate was stirred at room temperature overnight, dried in an oven at 100°C for 12 h to obtain Zr(OH)4;

[0037] (2) Preparation of double-layer hydroxide Zr(OH)4@Zr(OH)4precursor: 2 g of Zr(NO3)4·5H2O was dissolved in 20 mL of deionized water, 1 g of Zr(OH)4 prepared in step (1) was added, and the mixture was stirred for 1 h, then ammonia water was added to adjust the pH of the solution to 10 to form a precipitate; the precipitate was stirred at room temperature overnight, washed with deionized water until neutral, filtered, and dried in an oven at 100°C for 12 h to obtain a double-layer Zr(OH)4@Zr(OH)4precursor;

[0038] (3) Preparation of SO4 2- / Zr@Zr catalyst: 45 mL of 1 mol / L sulfuric acid was used to acidify 3 g of the double-layer Zr(OH)4@Zr(OH)4precursor prepared in step (2); after acidification, the mixture was dried in an oven at 100°C for 12 h and calcined in a muffle furnace at 550°C for 4 h to obtain a SO4 2- / Zr@Zr catalyst.

[0039] A solid superacid catalyst is prepared by the above preparation method.

[0040] Example 2

[0041] Example 2 provides a solid superacid catalyst and a preparation method thereof, which is different from example 1 in that the temperature of the oven in steps (1), (2) and (3) is 90°C, and the drying time is 14 h, and the rest is the same as example 1 to obtain the catalyst.

[0042] Example 3

[0043] Example 3 provides a solid superacid catalyst and a preparation method thereof. The difference from Example 1 is that the oven temperature in steps (1), (2), and (3) is 130° C., the drying time is 10 h, and the rest is the same as in Example 1 to obtain a catalyst.

[0044] Example 4

[0045] Example 4 provides a solid superacid catalyst and a preparation method thereof. The difference from Example 1 is that the concentration of sulfuric acid in step (3) is 0.5 mol / L, and the rest is the same as Example 1 to obtain a catalyst.

[0046] Example 5

[0047] Example 5 provides a solid superacid catalyst and a preparation method thereof. The difference from Example 1 is that the concentration of sulfuric acid in step (3) is 2 mol / L, and the rest is the same as Example 1 to prepare a catalyst.

[0048] Example 6

[0049] Example 6 provides a solid superacid catalyst and a preparation method thereof, which differs from Example 1 in that: in steps (1) and (2), the pH of the solution is adjusted to 9 by ammonia water, and the rest is the same as in Example 1 to obtain a catalyst.

[0050] Example 7

[0051] Example 7 provides a solid superacid catalyst and a preparation method thereof, which differs from Example 1 in that: in steps (1) and (2), the pH of the solution is adjusted to 11 by ammonia water, and the rest is the same as Example 1 to obtain a catalyst.

[0052] Example 8

[0053] Example 8 provides a method for preparing a solid superacid catalyst, the specific process is as follows:

[0054] (1) Preparation of single-layer Ti(OH)4 hydroxide: 10 g of TiCl4 was dissolved in 100 mL of deionized water, and ammonia was added dropwise to adjust the pH of the solution to 9 to form a precipitate. The precipitate was stirred at room temperature overnight and dried in an oven at 90°C for 10 h to obtain Ti(OH)4.

[0055] (2) Preparation of double-layer hydroxide Ti(OH)4@Ti(OH)4 precursor: 2 g of TiCl4 was dissolved in 20 mL of deionized water, 2 g of Ti(OH)4 obtained in step (1) was added, and the mixture was stirred for 55 min. Ammonia was added dropwise to adjust the pH of the solution to 9 to form a precipitate. The precipitate was stirred at room temperature overnight, washed with deionized water until neutral, filtered, and dried in an oven at 90°C for 10 h to obtain a double-layer Ti(OH)4@Ti(OH)4 precursor.

[0056] (3) Preparation of SO4 2- / Ti@Ti catalyst: 4 g of the double-layer Ti(OH)4@Ti(OH)4 precursor prepared in step (2) was subjected to acidification treatment with 40 mL of 0.5 mol / L sulfuric acid; after the acidification treatment was completed, the sample was dried in an oven at 90°C for 10 h and calcined in a muffle furnace at 500°C for 3 h to prepare the SO4 2- / Ti@Ti catalyst.

[0057] A solid superacid catalyst was prepared by the above preparation method.

[0058] Example 9

[0059] Example 9 provides a solid superacid catalyst and a preparation method thereof, and the specific process is as follows:

[0060] (1) Preparation of single-layer hydroxide Ti(OH)4: 10 g of TiCl4 was dissolved in 100 mL of deionized water, and ammonia water was added dropwise to adjust the pH of the solution to 10 to form a precipitate; the precipitate was stirred at room temperature overnight and dried in an oven at 100°C for 12 h to prepare Ti(OH)4;

[0061] Steps (2) and (3) are the same as in Example 1 to prepare the catalyst.

[0062] Example 10

[0063] Example 10 provides a preparation method of a solid superacid catalyst, and the specific process is as follows:

[0064] (1) Preparation of single-layer hydroxide Ce(OH)3: 10 g of Ce(NO3)3 was dissolved in 100 mL of deionized water, and ammonia water was added dropwise to adjust the pH of the solution to 11 to form a precipitate; the precipitate was stirred at room temperature overnight and dried in an oven at 120°C for 14 h to prepare Ce(OH)3;

[0065] (2) Preparation of double-layer hydroxide Ce(OH)3@Ce(OH)3 precursor: 2 g of Ce(NO3)3 was dissolved in 20 mL of deionized water, 0.4 g of Ce(OH)3 prepared in step (1) was added, and the mixture was stirred for 65 min; ammonia water was added dropwise to adjust the pH of the solution to 11 to form a precipitate; the precipitate was stirred at room temperature overnight, washed with deionized water until neutral, filtered, and dried in an oven at 120°C for 14 h to prepare the double-layer Ce(OH)3@Ce(OH)3 precursor;

[0066] (3) Preparation of SO4 2- / Ce@Ce catalyst: 3 g of the double-layer Ce(OH)3@Ce(OH)3 precursor prepared in step (2) was subjected to acidification treatment using 60 mL of 2 mol / L sulfuric acid; after the acidification treatment was completed, drying was performed in an oven at 120 °C for 14 h, and calcination was performed in a muffle furnace at 650 °C for 5 h to prepare a SO4 2- / Ce@Ce catalyst.

[0067] A solid superacid catalyst was prepared by the preparation method.

[0068] Example 11

[0069] Example 11 provides a solid superacid catalyst and a preparation method thereof, and the specific process is as follows:

[0070] (1) Preparation of single-layer hydroxide Ce(OH)3: 10 g of Ce(NO3)3 was dissolved in 100 mL of deionized water, and ammonia water was added dropwise to adjust the pH of the solution to 10 to form a precipitate; the precipitate was stirred at room temperature overnight, dried in an oven at 100 °C for 12 h, and Ce(OH)3 was prepared;

[0071] Steps (2) and (3) are the same as in Example 1, and the catalyst is prepared.

[0072] Example 2

[0073] Example 2 provides a solid superacid catalyst and a preparation method thereof, and the specific process is as follows:

[0074] Example 2 provides a solid superacid catalyst and a preparation method thereof, and the specific process is as follows:

[0075] (1) Preparation of ZrO2 solid powder: 2 g of Zr(NO3)4·5H2O was dissolved in 20 mL of deionized water, and ammonia water was added dropwise to adjust the pH of the solution to 10 to form a precipitate; the precipitate was stirred at room temperature overnight, washed with deionized water until neutral, filtered, dried in an oven at 100 °C for 12 h, and calcined in a muffle furnace at 550 °C for 4 h to prepare ZrO2 solid powder;

[0076] (2) Preparation of SO4 2- / Zr catalyst: 3 g of the ZrO2 solid powder prepared in step (1) was subjected to acidification treatment using 45 mL of 1 mol / L sulfuric acid; after the acidification treatment was completed, drying was performed in an oven at 100 °C for 12 h, and calcination was performed in a muffle furnace at 550 °C for 4 h to prepare a SO4 2- / Zr catalyst.

[0077] Example 2

[0078] Example 2 provides a solid superacid catalyst and a preparation method thereof, and the specific process is as follows:

[0079] Comparative Example 3

[0080] Comparative Example 3 provides a solid superacid catalyst and a preparation method thereof. The difference from Example 1 is that the calcination temperature in step (3) is 750° C., and the rest is the same as Example 1 to obtain a catalyst.

[0081] 3. Test Examples

[0082] Test Example 1

[0083] Test Example 1 The catalytic performance of the catalysts prepared in Examples 1 to 11 and Comparative Examples 1 to 3 was tested by liquid chromatography. The specific process is as follows:

[0084] To a 100 mL four-necked flask equipped with a magnet, thermometer, and condenser, 4.5 g of phenol, 1.5 g of fluorenone, and 0.65 g of the catalysts prepared in Examples 1-11 and Comparative Examples 1-3 were added, in that order. 10 mL of toluene was added, and the temperature was raised to 30°C with stirring. 0.04 mL of β-mercaptopropionic acid was added, and the temperature was continued to 110°C. The reaction was allowed to proceed for 3 hours. After the reaction, the resulting liquid was sampled and analyzed by liquid chromatography. The results are shown in Table 1.

[0085] Table 1

[0086]

[0087]

[0088] Compared to Example 1, Comparative Example 1 directly acidified the ZrO2 solid powder; Comparative Example 2 lowered the calcination temperature; and Comparative Example 3 increased the calcination temperature. As shown in Table 1, compared to Comparative Examples 1-3, the catalyst prepared in this application achieved a fluorenone conversion rate of 99.91% and a product selectivity of 99.86%. This demonstrates that the catalyst prepared in this invention exhibits excellent catalytic performance.

[0089] Test Example 2

[0090] Test Example 2 Infrared spectroscopy and X-ray diffraction were used to characterize the physicochemical properties of the catalyst prepared in Example 1. Figures 1-2 shown.

[0091] Figure 1 SO4 prepared in Example 1 2- XRD pattern of / Zr@Zr double layer solid super acid. Figure 1 It can be seen that the catalyst prepared in Example 1 has peaks at 30.2°, 35.3°, 50.3°, 60.2°, and 62.8°, respectively, corresponding to the (011), (110), (112), (013), and (121) planes of the tetragonal phase (t-ZrO2, PDF: 50-1089).

[0092] Figure 2 SO4 prepared in Example 1 2- FT-IR pattern of Zr@Zr double-layered solid superacid prepared in Example 1. From Figure 2 It can be seen that the wave peak at about 3431 cm -1 corresponds to the stretching of v O-H OH of water, 1636 cm -1 is attributed to the δ O-H bending vibration of water, 1240 cm -1 , 1137 cm -1 , 1080 cm -1 , 1048 cm -1 and 996 cm -1 are characteristic peaks of inorganic chelating bidentate sulfate. In addition, the peaks between 800 cm -1 and 520 cm -1 are characteristic peaks of Zr-O bond.

[0093] Test Example 3

[0094] Test Example 3 explores the influence of different molar ratios of phenol and fluorenone on the synthesis rate of bisphenol compounds, and the specific process is as follows:

[0095] ① Respectively take 4.5 g of phenol, 1.5 g of fluorenone (molar ratio of phenol to fluorenone is 6:1); 3.917 g of phenol, 1.5 g of fluorenone (molar ratio of phenol to fluorenone is 5:1); 6.267 g of phenol, 1.5 g of fluorenone (molar ratio of phenol to fluorenone is 8:1);

[0096] ② Add the solid superacid catalyst prepared in Example 1, 10 mL of toluene, and stir to warm to 30°C. Add β-mercaptopropionic acid and continue to warm to 110°C for 3 hours. Among them, the amount of Example 1 catalyst is 10% of the total weight of the reactants, and the amount of β-mercaptopropionic acid is 0.65% of the total weight of the reactants. After the reaction is completed, sample the obtained liquid and perform liquid chromatography analysis, and the results are shown in Table 2.

[0097] Table 2

[0098]

[0099]

[0100] From Table 2, it can be seen that the molar ratio of phenol and fluorenone affects the synthesis rate of bisphenol compounds. Among them, when the molar ratio of phenol and fluorenone is 6:1, the synthesis rate of bisphenol compounds is optimal.

[0101] Test Example 4

[0102] Test Example 4 explores the influence of different catalyst amounts on the synthesis rate of bisphenol compounds. The specific process is as follows:

[0103] Take 4.5g of phenol, 1.5g of fluorenone, and add 0.496g, 0.65g, and 0.744g of the solid superacid catalyst prepared in Example 1 (catalyst to phenol and fluorenone total mass ratio is 1:12, 1:9, and 1:8, respectively), 10mL of toluene, and stir while heating to 30°C. Add 0.04mL of β-mercaptopropionic acid and continue heating to 110°C for 3 hours. After the reaction is complete, sample the resulting liquid and perform liquid chromatography analysis. The results are shown in Table 3.

[0104] Table 3

[0105]

[0106] As shown in Table 3, the total mass ratio of catalyst to phenol and fluorenone affects the synthesis rate of bisphenol compounds. Among them, when the total mass ratio of catalyst to phenol and fluorenone is 1:9, the synthesis rate of bisphenol compounds is optimal.

[0107] Test Example 5

[0108] Test Example 5 explores the influence of different β-mercaptopropionic acid volumes on the synthesis rate of bisphenol compounds. The specific process is as follows:

[0109] Take 4.5g of phenol, 1.5g of fluorenone, and add 0.65g of the solid superacid catalyst prepared in Example 1, 10mL of toluene, and stir while heating to 30°C. Add 0.04mL, 0.0198mL, and 0.062mL of β-mercaptopropionic acid (β-mercaptopropionic acid volume to phenol and fluorenone total mass ratio is 1mL:160g, 1mL:100g, and 1mL:300g, respectively) and continue heating to 110°C for 3 hours. After the reaction is complete, sample the resulting liquid and perform liquid chromatography analysis. The results are shown in Table 4.

[0110] Table 4

[0111]

[0112] As shown in Table 4, the total mass ratio of β-mercaptopropionic acid volume to phenol and fluorenone affects the synthesis rate of bisphenol compounds. Among them, when the total mass ratio of β-mercaptopropionic acid volume to phenol and fluorenone is 1mL:160g, the synthesis rate of bisphenol compounds is optimal.

[0113] In summary, in the reaction of phenol, solvent, and fluorenone to synthesize bisphenol compounds, the optimal reaction rate conditions are as follows: the molar ratio of phenol to fluorenone is 6:1; the total mass ratio of catalyst to phenol and fluorenone is 1:9; and the total mass ratio of β-mercaptopropionic acid volume to phenol and fluorenone is 1mL:160g.

[0114] Test Example 6

[0115] Test Example 6 explores the catalytic performance of the solid super acid catalyst of Example 1, and the specific process is as follows:

[0116] ①The solid super acid catalyst prepared in Example 1 is applied to the synthesis of bisphenol compounds from phenol and fluorenone, and the specific process is as follows:

[0117] Into a 100 mL four-necked flask equipped with a magnetic stirrer, a thermometer, and a condenser, 4.5 g of phenol, 1.5 g of fluorenone, 0.65 g of the solid super acid catalyst prepared in Example 1, and 10 mL of toluene were sequentially added. The mixture was stirred and heated to 30°C, and 0.04 mL of β-mercaptopropionic acid was added. The temperature was continuously increased to 110°C, and the reaction was carried out for 3 hours. After the reaction was completed, the obtained liquid was sampled and subjected to liquid chromatography analysis.

[0118] According to the liquid chromatography detection, the conversion rate of fluorenone was 99.91%, and the product selectivity was 99.86%.

[0119] ②The solid super acid catalyst prepared in Example 1 is applied to the synthesis of bisphenol compounds from phenol and acetone, and the specific process is as follows:

[0120] Into a 100 mL four-necked flask equipped with a magnetic stirrer, a thermometer, and a condenser, 14.58 g of phenol, 1.5 g of acetone, 1.608 g of the solid super acid catalyst prepared in Example 1, and 10 mL of toluene were sequentially added. The mixture was stirred and heated to 30°C, and 0.104 mL of β-mercaptopropionic acid was added. The temperature was continuously increased to 110°C, and the reaction was carried out for 3 hours. After the reaction was completed, the obtained liquid was sampled and subjected to liquid chromatography analysis.

[0121] According to the liquid chromatography detection, the conversion rate of acetone was 99.4%, and the product selectivity was 99.57%.

[0122] ③The solid super acid catalyst prepared in Example 1 is applied to the synthesis of bisphenol compounds from phenol and formaldehyde, and the specific process is as follows:

[0123] Into a 100 mL four-necked flask equipped with a magnetic stirrer, a thermometer, and a condenser, 117.5 g of phenol, 1.5 g of formaldehyde, 11.9 g of the solid super acid catalyst prepared in Example 1, and 10 mL of toluene were sequentially added. The mixture was stirred and heated to 30°C, and 0.79 mL of β-mercaptopropionic acid was added. The temperature was continuously increased to 110°C, and the reaction was carried out for 3 hours. After the reaction was completed, the obtained liquid was sampled and subjected to liquid chromatography analysis.

[0124] According to the liquid chromatography detection, the conversion rate of formaldehyde was 99.1%, and the product selectivity was 99.28%.

[0125] As can be seen from the above, the catalyst provided by the present invention can achieve a conversion rate of reactants of 99.91% and a product selectivity of 99.86%. It can be seen that the catalyst of the present invention has excellent catalytic performance.

[0126] Test Example 7

[0127] Test Example 7 investigates the reusability of the solid superacid catalyst of Example 1. The specific process is as follows:

[0128] ① Catalyst recovery: The reaction solution was centrifuged to separate the solid catalyst, which was washed with ethanol, dried at 100° C. for 12 h, and then calcined in a muffle furnace at 550° C. for 4 h to obtain the recovered solid superacid catalyst of Example 1;

[0129] ② The catalyst recovered in step ① was repeated 5 times to catalyze phenol and fluorenone to synthesize bisphenol compounds. The reaction conditions were the same as those in Test Example 3. The performance of the catalyst after 5 cycles of experiments was as follows: Figure 3 shown.

[0130] Depend on Figure 3 It can be seen that after the core-shell structure catalyst prepared in the present invention is reused for 5 times, the conversion rate of the reactants is still higher than 98%, that is, the catalyst prepared in the present invention has good reusability.

[0131] In summary, the preparation method provided by the present invention is to adjust the pH of the solution with ammonia water twice to obtain a metal salt precursor, and the metal salt precursor is acidified to obtain a solid superacid catalyst. It can be seen that the raw materials prepared by the present invention are cheap and easy to obtain, the preparation process is simple, and it is green and environmentally friendly. The core-shell structure catalyst of the present invention has excellent catalytic performance. After being reused 5 times, the conversion rate of the reactant is still higher than 98%, which has the advantages of being reusable many times and low energy consumption. When the catalyst prepared by the present invention is used to synthesize bisphenol compounds, the conversion rate of the reactant reaches 99.91% and the product selectivity reaches 99.86%, which has broad application prospects.

[0132] The above are only preferred embodiments of the present invention and are not limited to the above examples. For those skilled in the art, various changes and modifications are possible under the principles of the present invention. Any modifications and improvements made should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a solid super acid catalyst for synthesizing bisphenol compounds, characterized by, The method comprises the following steps: (1) Preparation of single-layer hydroxide M(OH) x : Dissolve the metal M salt in deionized water, adjust the pH of the solution with ammonia water, form a precipitate, stir the precipitate overnight, dry, and prepare the hydroxide M(OH) x ; (2) Preparation of double-layer hydroxide M(OH) x @M(OH) x Precursor: Dissolve metal M salt in deionized water, add M(OH) x @M(OH) x @M(OH) x Precursor; (3) Preparation of SO4 2- / M@M catalyst: The M(OH) x @M(OH) x The precursor is acidized, and after acidization is completed, the SO4 2- / M@M catalyst is prepared through drying and calcination. The step (1), (2) metal M salt is Zr 4+ , Ti 4+ , Ce 3+ nitrate or chloride; the temperature of the calcination is 500-650℃; the time of the calcination is 3-5h.

2. The method for preparing a solid superacid catalyst for synthesizing bisphenol compounds as claimed in claim 1, wherein: The concentration of the metal M salt solution in the steps (1) and (2) is 0.1 g / mL.

3. The method of claim 1, wherein the solid super acid catalyst for the synthesis of bisphenol compounds is prepared by the steps of: (1) preparing a mixture of a metal salt and a metal oxide; (2) mixing the mixture with a solvent; (3) adding a base to the mixture; (4) drying the mixture; and (5) calcining the mixture. The step (2) metal M salt and M(OH) x The mass ratio of (1~5):

1.

4. The method for preparing a solid superacid catalyst for synthesizing bisphenol compounds as claimed in claim 1, wherein: The ammonia water is used to adjust the pH of the solution to 9-11 in the steps (1) and (2).

5. The method of claim 1, wherein the solid super acid catalyst for the synthesis of bisphenol compounds is prepared by the steps of: (1) preparing a mixture of a metal salt and a metal oxide; (2) mixing the mixture with a solvent; (3) adding a base to the mixture; (4) drying the mixture; and (5) calcining the mixture. The concentration of sulfuric acid in the step (3) is 0.5-2 mol / L, M(OH) x @M(OH) x The mass of the precursor to the volume of sulfuric acid is 1 g:(10-20) mL.

6. The method for preparing a solid superacid catalyst for synthesizing bisphenol compounds as claimed in claim 1, wherein: The drying temperature in the steps (1), (2) and (3) is 90-120 ℃, and the drying time is 10-14 h.

7. A solid super acid catalyst for the synthesis of bisphenol compounds, characterized by, The method is prepared by the preparation method in any one of claims 1-6.

8. The use of the solid super acid catalyst for synthesizing bisphenol compounds according to claim 7, wherein the solid super acid catalyst is used in an amount of 0.1 to 10% by weight based on the total weight of the reaction mixture. The application of the catalyst in the synthesis of bisphenol compounds.

9. The use of the solid super acid catalyst for synthesizing bisphenol compounds according to claim 8, wherein the solid super acid catalyst is used in an amount of 0.1 to 10% by weight based on the total weight of the reaction mixture. The bisphenol compounds are synthesized from phenol and ketone or aldehyde compounds under the action of the catalyst and the co-catalyst; the ketone compound is fluorenone or acetone, the aldehyde compound is formaldehyde, and the co-catalyst is β-mercaptopropionic acid; the temperature of the synthesis reaction is 100-130 ℃, and the time is 2-5 h.

10. The use of a solid superacid catalyst for synthesizing bisphenol compounds as claimed in claim 8, characterized in that: In the reaction of synthesizing the bisphenol compounds, the molar ratio of phenol to ketone compound is (5-8):1; the molar ratio of phenol to aldehyde compound is (25-30):1; the ratio of the total mass of the catalyst to phenol, aldehyde or ketone compound is 1:(8-12); and the ratio of the volume of β-mercaptopropionic acid to the total mass of phenol, aldehyde or ketone compound is 1 mL:(100-300) g.

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