An ionic liquid-modified rare earth-doped solid acid catalyst and a preparation method thereof

Abstract

This invention provides an ionic liquid-modified rare earth-doped solid acid catalyst and its preparation method. The preparation method includes the following steps: (1) mixing a carrier salt solution with a rare earth element salt, adding a pH adjuster to adjust the pH, and then subjecting the mixture to static aging and a first solid-liquid separation to obtain a first solid; (2) subjecting the first solid to crushing and calcination to obtain a second solid; (3) immersing the second solid in an ionic liquid, and then subjecting it to ultrasonic treatment, a second solid-liquid separation, washing, and drying to obtain the ionic liquid-modified rare earth-doped solid acid catalyst. The preparation method of this invention is simple to operate and enhances the catalytic performance of the solid acid catalyst for the alkylbenzene α-hydroperoxide cracking reaction through rare earth element doping and ionic liquid loading modification.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation technology, and in particular to an ionic liquid-modified rare earth-doped solid acid catalyst and its preparation method. Background Technology

[0002] Alkylbenzene α-hydroperoxide cracking is an important reaction for the preparation of phenol and corresponding aldehyde and ketone compounds. Phenol is an important chemical raw material and a crucial intermediate in the synthesis of plastics, pesticides, pharmaceuticals, and fungicides. In recent years, in particular, with the gradual expansion of the application of polycarbonate, epoxy resin, and phenolic resin in the electronics, automotive, and electrical appliance industries, the demand for phenol has been further released. It is expected that with the expansion of the new materials industry, the demand for phenol will continue to grow in the future.

[0003] Representative alkylbenzene α-hydroperoxide cracking processes, such as the cracking of cumene peroxide to produce phenol and acetone, and the cracking of cyclohexylbenzene peroxide to produce phenol and cyclohexanone, typically use strong protic acids as catalysts, such as sulfuric acid, phosphoric acid, hydrochloric acid, perchloric acid, and benzenesulfonic acid, with sulfuric acid being the most common. Ketones such as acetone are used as dispersion solvents for the acid catalyst. After the cracking reaction, the acid catalyst is neutralized with an alkaline substance, and the desired materials are then separated by filtration, distillation, and other methods. This process involves the use of highly acidic and corrosive sulfuric acid, requiring equipment with high corrosion resistance and significant investment. The acid catalyst needs to be neutralized with an alkali after the cracking reaction, generating large amounts of saline wastewater, resulting in high process costs and significant pollution. With increasingly stringent environmental requirements, the development of green, low-cost, and high-value-added phenol and ketone production technologies has become a growing focus.

[0004] Solid acid catalysts, as important heterogeneous catalysts, are widely used in many fields. Their use in the catalytic cracking of cumene peroxide or cyclohexylbenzene peroxide has also been reported. However, during the reaction, the peroxide bond of the peroxide is prone to deoxygenation to generate the corresponding α-hydroxyalkylbenzene, or further dehydration to generate the corresponding phenyl olefin impurities. Therefore, there are problems such as low reaction selectivity, a large number of reaction by-products, and short catalyst lifetime.

[0005] CN106536461A discloses a method for controlling the hydroperoxide cracking of alkyl aromatic hydrocarbons, using C in the presence of a zeolite catalyst. 2-6 Alkyl source alkylates benzene to produce C 8-12 Alkylbenzene; oxidation of the C in the presence of oxygen-containing gas 8-12 Alkylbenzene thus produces C 8-12 Alkylbenzene hydroperoxide; cleavage and decomposition of the C in the presence of an acid catalyst. 8-12 Alkylbenzene hydroperoxides are used to produce phenol, C 3-6Ketones and undesirable byproducts, such as, but not limited to, acetaldehyde, DMBA, acetophenone, AMS, AMS dimer, unidentified heavy substances, or combinations containing at least one of the above; and the C in the reactor process stream being monitored in real time at the temperature and pressure of the process stream. 8-12 The concentration of alkylbenzene hydroperoxide; and in response to the C 8-12 The concentration of alkylbenzene hydroperoxide is used to control the parameters of the reactor and / or the pyrolysis decomposition in real time.

[0006] CN1348944A discloses a method for cracking alkyl aryl hydroperoxides, wherein a mixture is produced comprising a concentrate containing at least one alkyl aryl hydroperoxide to be cracked and cracking products obtained from the cracking of alkyl aryl hydroperoxides. This mixture is divided into at least two parts, in which the alkyl aryl hydroperoxides are cracked in parallel at different temperatures. One of the two parts of the mixture is treated at such a high temperature to achieve integrated thermal post-treatment. Compared with conventional methods, this method significantly reduces energy consumption or eliminates the need for any steam, greatly avoids scaling problems in heat transfer equipment, and reduces safety costs because a second feed point for alkyl aryl hydroperoxides is not required.

[0007] CN105646156A discloses a method for preparing phenol. The method includes oxidizing at least a portion of a feed containing cyclohexylbenzene to prepare an oxidizing composition containing cyclohexyl-1-phenyl-1-hydroperoxide. The oxidizing composition can then be pyrolyzed in the presence of an acid catalyst to prepare a pyrolysis reaction mixture containing an acid catalyst, phenol, and cyclohexanone. At least a portion of the pyrolysis reaction mixture can be neutralized with a basic material to form a treated pyrolysis reaction mixture. In several embodiments, the treated pyrolysis reaction mixture contains no more than 50 wppm of an acid catalyst or no more than 50 wppm of a basic material.

[0008] However, the conversion rate and selectivity of the above-mentioned alkylbenzene α-hydroperoxide cracking reaction still need to be further improved. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides an ionic liquid-modified rare earth-doped solid acid catalyst and its preparation method. By doping rare earth elements into a solid acid support and modifying it with an ionic liquid, the catalytic performance of the solid acid catalyst for the cracking reaction of alkylbenzene α-hydroperoxide is enhanced, various side reactions are reduced, and the conversion rate of alkylbenzene α-hydroperoxide is improved, showing broad application prospects.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a method for preparing an ionic liquid-modified rare earth-doped solid acid catalyst, characterized in that the preparation method comprises the following steps:

[0012] (1) After mixing the carrier salt solution and rare earth element salt, add pH adjuster to adjust pH, and then let it stand for aging and undergo the first solid-liquid separation to obtain the first solid.

[0013] (2) The first solid material is subjected to crushing and roasting processes in sequence to obtain the second solid material;

[0014] (3) The second solid is immersed in an ionic liquid and then subjected to ultrasonic treatment, second solid-liquid separation, washing and drying in sequence to obtain an ionic liquid modified rare earth doped solid acid catalyst.

[0015] The method for preparing the ionic liquid-modified rare earth-doped solid acid catalyst of the present invention involves rare earth element doping by mixing a carrier salt solution with rare earth element salts, thereby improving the acid strength of the solid acid carrier. At the same time, the carrier is modified by loading with ionic liquid, which increases the number of active sites on the surface and in the pores of the solid acid and improves the acid strength at the reaction sites. This enhances the catalytic performance of the solid acid catalyst for the cracking reaction of alkylbenzene α-hydroperoxide, while greatly reducing side reactions such as deoxygenation and dehydration of peroxide bonds to generate impurities such as α-hydroxyalkylbenzene and phenylolefins, thus improving the selectivity of phenol and ketone products.

[0016] Preferably, the carrier salt solution in step (1) includes any one or a combination of at least two of zirconium chloride solution, zirconium nitrate solution, zirconium sulfate solution, zirconium acetate solution, titanium chloride solution, titanium nitrate solution, titanium sulfate solution, or titanium acetate solution. Typical but non-limiting combinations include a combination of zirconium chloride solution and zirconium nitrate solution, a combination of zirconium sulfate solution and zirconium acetate solution, a combination of titanium chloride solution and titanium nitrate solution, or a combination of titanium sulfate solution and zirconium chloride solution.

[0017] Preferably, the concentration of the carrier salt solution is 0.5% to 30%, for example, it can be 0.5%, 1%, 3%, 5%, 10%, 15%, 20% or 30%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] Preferably, the rare earth element salt includes any one or a combination of at least two of cerium chloride, cerium nitrate, cerium sulfate, cerium acetate, lanthanum chloride, lanthanum nitrate, lanthanum sulfate, or lanthanum acetate, wherein typical but non-limiting combinations include a combination of cerium chloride and cerium nitrate, a combination of cerium sulfate and cerium acetate, a combination of lanthanum chloride and lanthanum nitrate, or a combination of lanthanum sulfate and cerium chloride.

[0019] Preferably, the liquid-to-solid ratio of the carrier salt solution to the rare earth element salt is 9.4 to 197,000 mL / g, for example, it can be 9.4 mL / g, 10 mL / g, 100 mL / g, 1000 mL / g, 10000 mL / g, 100000 mL / g, 1000000 mL / g, or 1970000 mL / g, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] Preferably, the pH adjuster in step (1) includes ammonia.

[0021] Preferably, the concentration of the ammonia water is 1% to 30%, for example, it can be 1%, 3%, 5%, 10%, 15%, 20% or 30%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0022] Preferably, the pH is adjusted to 7-13, such as 7, 8, 9, 10, 11, 12 or 13, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0023] Preferably, the settling and aging time is 12 to 48 hours, for example, it can be 12 hours, 15 hours, 20 hours, 30 hours, 25 hours, 40 hours or 48 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0024] Preferably, the calcination temperature in step (2) is 500 to 800°C, for example, it can be 500°C, 550°C, 600°C, 650°C, 700°C, 750°C or 800°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] The preferred calcination temperature of this invention is 500–800°C, which has the advantage of forming more acidic centers. If the calcination temperature is too low, acidic reaction centers cannot be effectively formed, resulting in a poorer alkylbenzene α-hydroperoxide cracking reaction. If the calcination temperature is too high, the crystal form of the solid acid support will change, reducing the selectivity of the main alkylbenzene α-hydroperoxide cracking reaction.

[0026] Preferably, the roasting time is 6 to 24 hours, for example, 6 hours, 8 hours, 10 hours, 12 hours, 15 hours, 20 hours or 24 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0027] Preferably, the second solid is crushed to 0.01-2 mm before impregnation in step (3).

[0028] In this invention, the second solid is immersed in an excess of ionic liquid to saturate the adsorption of the second solid.

[0029] Preferably, the ionic liquid comprises a 1-alkyl-3-methylimidazolium salt [RMIM]. + [B] - N-alkylpyridine hydrogen sulfate [RPy] + [B] - 1-Carboxylic acid alkyl-3-methylimidazolium salt [ROOHMIM] + [B] - N-Carboxylic Alkylpyridine Hydrogen Sulfate [ROOHPy] + [B] - 1-Sulfonic acid alkyl-3-methylimidazolium salt [RSO3HMIM] + [B] - Or N-sulfonic acid alkylpyridine hydrogen sulfate [RSO3HPy] + [B] - Any one or at least two of the following, wherein typical but non-limiting combinations include 1-alkyl-3-methylimidazolium salt [RMIM]. + [B] - and N-alkylpyridine hydrogen sulfate [RPy] + [B] - The combination of 1-carboxylic acid alkyl-3-methylimidazolium salt [ROOHMIM] + [B] - And N-carboxylic acid alkylpyridine hydrogen sulfate [ROOHPy] + [B] - Combinations or 1-sulfonic acid alkyl-3-methylimidazolium salt [RSO3HMIM] + [B] - And N-sulfonic acid alkylpyridine hydrogen sulfate [RSO3HPy] + [B] - The combination of .

[0030] Preferably, R in the ionic liquid is a C1 to C6 alkyl group, for example, it can be a C1 alkyl group, a C2 alkyl group, a C3 alkyl group, a C5 alkyl group or a C6 alkyl group.

[0031] Preferably, B - It consists of hydrogen sulfate or hydrogen phosphate.

[0032] The present invention preferably uses the B - It consists of hydrogen sulfate or hydrogen phosphate, which, compared to chloride ions, have the advantages of high acid strength and good alkylbenzene α-hydroperoxide cracking reaction performance.

[0033] Preferably, the frequency of the ultrasonic treatment is 20 to 60 kHz, such as 20 kHz, 25 kHz, 30 kHz, 35 kHz, 40 kHz, 50 kHz or 60 kHz, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] Preferably, the temperature of the ultrasonic treatment is 40 to 80°C, for example, it can be 40°C, 45°C, 50°C, 60°C, 70°C, 75°C or 80°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] Preferably, the ultrasonic treatment time is 20 to 600 min, for example, it can be 20 min, 500 min, 100 min, 200 min, 300 min, 500 min or 600 min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] The solid-liquid separation described in this invention is not limited, and any method known to those skilled in the art for solid-liquid separation can be used, such as filtration, sedimentation, or centrifugation.

[0037] As a preferred technical solution of the present invention, the preparation method includes the following steps:

[0038] (1) After mixing a carrier salt solution with a concentration of 0.5% to 30% and a rare earth element salt with a liquid-to-solid ratio of 9.4 to 197000 mL / g, ammonia water with a concentration of 1% to 30% was added to adjust the pH to 7 to 13. The mixture was then allowed to stand for 12 to 48 hours and then subjected to the first solid-liquid separation to obtain the first solid.

[0039] The carrier salt solution includes any one or a combination of at least two of zirconium chloride solution, zirconium nitrate solution, zirconium sulfate solution, zirconium acetate solution, titanium chloride solution, titanium nitrate solution, titanium sulfate solution, or titanium acetate solution; the rare earth element salt includes any one or a combination of at least two of cerium chloride, cerium nitrate, cerium sulfate, cerium acetate, lanthanum chloride, lanthanum nitrate, lanthanum sulfate, or lanthanum acetate.

[0040] (2) The first solid material is subjected to crushing treatment and calcination treatment at a temperature of 500-800℃ for 6-24 hours to obtain the second solid material;

[0041] (3) After the second solid is crushed to 0.01-2 mm, it is immersed in an ionic liquid and subjected to ultrasonic treatment at a frequency of 20-60 kHz and a temperature of 40-80 °C for 20-600 min, followed by solid-liquid separation, washing and drying to obtain an ionic liquid modified rare earth doped solid acid catalyst.

[0042] The ionic liquid includes 1-alkyl-3-methylimidazolium salt [RMIM]. + [B] - N-alkylpyridine hydrogen sulfate [RPy] + [B] - 1-Carboxylic acid alkyl-3-methylimidazolium salt [ROOHMIM] + [B] - N-Carboxylic Alkylpyridine Hydrogen Sulfate [ROOHPy] + [B] - 1-Sulfonic acid alkyl-3-methylimidazolium salt [RSO3HMIM] + [B] - Or N-sulfonic acid alkylpyridine hydrogen sulfate [RSO3HPy] + [B] - In the ionic liquid, R is a C1-C6 alkyl group, and B is a combination of any one or at least two of the following: - It consists of hydrogen sulfate or hydrogen phosphate.

[0043] In a second aspect, the present invention also provides an ionic liquid-modified rare earth-doped solid acid catalyst, wherein the ionic liquid-modified rare earth-doped solid acid catalyst is prepared by the preparation method of the ionic liquid-modified rare earth-doped solid acid catalyst described in the first aspect; the rare earth element doping amount of the ionic liquid-modified rare earth-doped solid acid catalyst is 0.1-10%.

[0044] The rare-earth-doped solid acid catalyst modified with ionic liquid described in this invention can directly react with alkylbenzene α-hydroperoxide solution, resulting in a fast catalytic cracking reaction, high conversion rate of alkyl α-hydroperoxide, low impurities, and good selectivity for phenol and ketone products. This solid acid catalyst can replace the existing sulfuric acid catalyst used for alkylbenzene α-hydroperoxide cracking. After the reaction, the solid and liquid phases are directly separated, the solid acid catalyst can be recycled, and the reaction solution does not require alkali neutralization; the product can be directly obtained by distillation. This reduces post-processing steps, lowers process steps and separation energy consumption, and avoids equipment corrosion and environmental pollution caused by the use of sulfuric acid.

[0045] The rare earth element doping amount of the ionic liquid modified rare earth doped solid acid catalyst of the present invention is 0.1% to 10%, for example, it can be 0.1%, 0.5%, 1%, 3%, 5%, 8% or 10%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] The rare earth element doping amount of the ionic liquid modified rare earth doped solid acid catalyst of this invention is 0.1% to 10%, which has the advantages of increasing the acidic sites and improving the acid strength of the solid acid. When the rare earth element doping amount is low, there will be fewer acidic sites, resulting in poor alkylbenzene α-hydroperoxide cracking reaction. When the rare earth element doping amount is high, the solid acid grain size will increase, the reactive sites will be covered, and the reaction effect will be worse.

[0047] Thirdly, the present invention also provides the use of the ionic liquid modified rare earth doped solid acid catalyst as described in the second aspect, wherein alkylbenzene α-hydroperoxide undergoes a contact reaction under the action of the ionic liquid modified rare earth doped solid acid catalyst to generate phenol and ketone aldehyde compounds, and the resulting reaction solution is subjected to solid-liquid separation to recover the solid acid catalyst, and the filtrate is separated by distillation to obtain the target product.

[0048] Preferably, the general structural formula of the alkylbenzene α-hydroperoxide is as follows:

[0049]

[0050] In the formula, R1 and R2 represent alkyl groups from C0 to C6, and the dashed part indicates that the two groups R1 and R2 remain independent or are connected to form a ring.

[0051] Preferably, the concentration of alkylbenzene α-hydroperoxide in the contact reaction is 5% to 75%, for example, it can be 5%, 8%, 10%, 30%, 50%, 60%, 70% or 75%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0052] Preferably, the amount of rare earth-doped solid acid catalyst modified by ionic liquid in the contact reaction is 0.5% to 20%, for example, it can be 0.5%, 1%, 3%, 10%, 15%, 16%, 17% or 20%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0053] Preferably, the temperature of the contact reaction is 30 to 120°C, for example, it can be 30°C, 50°C, 70°C, 90°C, 100°C, 110°C or 120°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0054] The preferred contact reaction temperature of this invention is 30–120°C. This ensures that during the cracking of alkylbenzene α-hydroperoxides by the solid acid catalyst to produce phenol and the corresponding alkyl ketones or aldehydes, minimal deoxygenation and dehydration side reactions of the peroxide bond occur, resulting in fewer impurities such as α-hydroxyalkylbenzenes and phenylolefins. Lower contact reaction temperatures lead to reduced cracking reactivity and lower conversion rates; higher contact reaction temperatures result in excessively high reactivity, increased side reactions, and reduced reaction selectivity.

[0055] Preferably, the contact reaction time is 10 to 120 minutes, for example, 10 minutes, 20 minutes, 50 minutes, 80 minutes, 100 minutes or 120 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0056] Compared with the prior art, the present invention has at least the following beneficial effects:

[0057] (1) The method for preparing rare earth-doped solid acid catalyst modified by ionic liquid provided by the present invention improves the acid strength of the solid acid matrix by doping with rare earth elements. At the same time, the matrix is ​​modified by loading with ionic liquid, which increases the number of active sites on the surface and in the pores of the solid acid and increases the acid strength at the reaction sites. This enhances the catalytic performance of the solid acid catalyst for the cracking reaction of alkylbenzene α-hydroperoxide. It also greatly reduces the side reactions of deoxygenation and dehydration of peroxide to generate impurities such as α-hydroxyalkylbenzene and phenyl olefins, and improves the selectivity of phenol and ketone products.

[0058] (2) The method for preparing rare earth-doped solid acid catalyst modified by ionic liquid provided by the present invention uses the prepared solid acid catalyst for the cracking reaction of alkylbenzene α-hydroperoxide. The reaction has high conversion rate, few side reactions, and good selectivity of phenol and ketone products. After the reaction, the catalyst can be directly filtered and recycled. The filtrate can be separated by distillation to obtain the desired product. The process is simple and environmentally friendly, with low production cost and has broad application prospects. Detailed Implementation

[0059] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0060] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0061] Example 1

[0062] This embodiment provides a method for preparing an ionic liquid-modified rare earth-doped solid acid catalyst, the preparation method comprising the following steps:

[0063] (1) Dissolve 30g of zirconium nitrate pentahydrate in 100g of deionized water, then add 0.17g of cerium nitrate hexahydrate to dissolve the solid completely. Add 20% ammonia water slowly while stirring. A precipitate is formed. Adjust the pH to 8. Let the solution stand for 24 hours. Filter and wash the filter cake with deionized water. Dry the filter cake at 120℃ for 3 hours. After drying, the first solid is obtained.

[0064] (2) 14.12g of the first solid was ground and crushed using a mortar and pestle. The crushed solid was then calcined in a muffle furnace at 600°C for 8 hours to obtain the second solid.

[0065] (3) Select catalyst solids with a particle size of 20-100 μm from 10.82 g of the second solid. Solids with excessively large particle sizes are ground and crushed a second time. 6.55 g of the selected solid is completely impregnated in 30 g of ionic liquid 1-n-pentanoic acid-3-methylimidazolium hydrogen sulfate [C4H8CO2HMIM]. + [HSO4] - The reaction was carried out in a four-necked flask under ultrasonic conditions of 50℃ and 20KHz for 150 min. After the reaction was completed, the solid was filtered, the filter cake was washed with deionized water, and the filter cake was dried at 120℃ to obtain 6.72 g of ionic liquid modified rare earth doped solid acid catalyst A.

[0066] 2.0 g of the catalyst A prepared above and 100 g of cumene peroxide solution were placed in a four-necked flask and stirred at 40 °C for 90 min. After the reaction was completed, the catalyst was separated by cooling and filtration. The filtrate was sampled and analyzed by gas chromatography. The results showed that the conversion rate of cumene peroxide was 100%, the selectivity of phenol was 99.8%, and the selectivity of acetone was 99.5%.

[0067] Example 2

[0068] This embodiment provides a method for preparing an ionic liquid-modified rare earth-doped solid acid catalyst, the preparation method comprising the following steps:

[0069] (1) Dissolve 50g of titanium chloride in 100g of deionized water, then add 0.65g of cerium nitrate hexahydrate to dissolve the solid completely. Slowly add 20% ammonia water while stirring. A precipitate is formed. Adjust the pH to 8, let the solution stand for 36h, filter and wash the filter cake with deionized water. Dry the filter cake at 120℃ for 3h. After drying, the first solid is obtained.

[0070] (2) 30.35g of the first solid was ground and crushed using a mortar and pestle. The crushed solid was then calcined in a muffle furnace at 600°C for 8 hours to obtain the second solid.

[0071] (3) Select catalyst solids with a particle size of 20-100 μm from 21.15 g of the second solid. Solids with excessively large particle sizes are ground and crushed a second time. 13.08 g of the selected solid is completely impregnated in 50 g of ionic liquid 1-n-butyl-3-methylimidazolium phosphate [C4H9MIM]. + [H2PO4] - The reaction was carried out in a four-necked flask under ultrasonic conditions of 50℃ and 20KHz for 200min. After the reaction was completed, the solid was filtered, the filter cake was washed with deionized water, and the filter cake was dried at 120℃ to obtain 14.21g of ionic liquid modified rare earth doped solid acid catalyst B.

[0072] 4.0 g of the catalyst B prepared above and 100 g of cumene peroxide solution were placed in a four-necked flask and stirred at 50 °C for 120 min. After the reaction was completed, the catalyst was separated by cooling and filtration. The filtrate was sampled and analyzed by gas chromatography. The results showed that the conversion rate of cumene peroxide was 95%, the selectivity of phenol was 98.5%, and the selectivity of acetone was 97.8%.

[0073] Example 3

[0074] This embodiment provides a method for preparing an ionic liquid-modified rare earth-doped solid acid catalyst, the preparation method comprising the following steps:

[0075] (1) Dissolve 25g of zirconium sulfate in 100g of deionized water, then add 0.34g of cerium nitrate hexahydrate to dissolve the solid completely. Add 25% ammonia water slowly while stirring. A precipitate is formed. Adjust the pH to 8. Let the solution stand for 48h. Filter and wash the filter cake with deionized water. Dry the filter cake at 120℃ for 3h. After drying, the first solid is obtained.

[0076] (2) 14.59g of the first solid was ground and crushed using a mortar and pestle. The crushed solid was then calcined in a muffle furnace at 700°C for 10 hours to obtain the second solid.

[0077] (3) Select catalyst solids with a particle size of 20-100 μm from 10.95 g of the second solid. Solids with excessively large particle sizes are ground and crushed a second time. 6.31 g of the selected solid is completely impregnated in 30 g of ionic liquid 1-propyl-3-methylimidazolium sulfonate [C3H6SO3HMIM]. + [HSO4] -The reaction was carried out in a four-necked flask under ultrasonic conditions of 60℃ and 30KHz for 120 min. After the reaction was completed, the solid was filtered, the filter cake was washed with deionized water, and the filter cake was dried at 120℃ to obtain 6.83 g of ionic liquid modified rare earth doped solid acid catalyst C.

[0078] 2.0 g of the catalyst C prepared above and 100 g of cumene peroxide solution were placed in a four-necked flask and stirred at 40 °C for 60 min. After the reaction was completed, the catalyst was separated by cooling and filtration. The filtrate was sampled and analyzed by gas chromatography. The results showed that the conversion rate of cumene peroxide was 100%, the selectivity of phenol was 99.9%, and the selectivity of acetone was 99.8%.

[0079] Example 4

[0080] This embodiment provides a method for preparing an ionic liquid-modified rare earth-doped solid acid catalyst, the preparation method comprising the following steps:

[0081] (1) Dissolve 25g zirconium sulfate in 100g deionized water, then add 0.096g lanthanum chloride to dissolve the solid completely. Add 25% ammonia water slowly while stirring. A precipitate is formed. Adjust the pH to 9. Let the solution stand for 24 hours. Filter and wash the filter cake with deionized water. Dry the filter cake at 120℃ for 3 hours. After drying, the first solid is obtained.

[0082] (2) 14.31g of the first solid was ground and crushed using a mortar and pestle. The crushed solid was then calcined in a muffle furnace at 800°C for 6 hours to obtain the second solid.

[0083] (3) Select catalyst solids with a particle size of 20-100 μm from 10.82 g of the second solid. Solids with excessively large particle sizes are ground and crushed a second time. 6.13 g of the selected solid is completely impregnated in 30 g of ionic liquid N-butylpyridine sulfonate hydrogen sulfate [C4H6SO3HPy]. + [HSO4] - The reaction was carried out in a four-necked flask under ultrasonic conditions of 50℃ and 20KHz for 90 min. After the reaction was completed, the solid was filtered, the filter cake was washed with deionized water, and the filter cake was dried at 120℃ to obtain 6.77 g of ionic liquid modified rare earth doped solid acid catalyst D.

[0084] The catalyst D prepared above (5.0 g) and cumene solution (40% concentration) were placed in a four-necked flask and stirred at 40°C for 90 min. After the reaction was completed, the catalyst was separated by cooling and filtration. The filtrate was sampled and analyzed by gas chromatography. The results showed that the conversion rate of cumene peroxide was 100%, the selectivity of phenol was 98.8%, and the selectivity of acetone was 98.1%.

[0085] Example 5

[0086] This embodiment provides a method for preparing an ionic liquid modified rare earth doped solid acid catalyst. Except for step (1) where 0.003 g of cerium nitrate hexahydrate is added, the rare earth element doping amount of the obtained solid acid catalyst is 0.01%, the rest of the preparation method is the same as in Example 1.

[0087] The rare earth-doped solid acid catalyst modified with ionic liquid prepared in this embodiment catalyzes the cumene peroxide solution under the same conditions as in Example 1. The calculated results are: cumene peroxide conversion rate of 98.2%, phenol selectivity of 99.1%, and acetone selectivity of 98.5%.

[0088] Example 6

[0089] This embodiment provides a method for preparing an ionic liquid modified rare earth doped solid acid catalyst. Except for step (1) where 3.96g of cerium nitrate hexahydrate is added, the rare earth element doping amount of the obtained solid acid catalyst is 13%, the preparation method is the same as in Example 1.

[0090] The rare earth-doped solid acid catalyst modified with ionic liquid prepared in this embodiment catalyzes the cumene peroxide solution under the same conditions as in Example 1. The calculated results are: cumene peroxide conversion rate of 97.9%, phenol selectivity of 97.7%, and acetone selectivity of 96.5%.

[0091] Example 7

[0092] This embodiment provides a method for preparing an ionic liquid modified rare earth doped solid acid catalyst. Except for the calcination temperature of 400°C in step (2), the preparation method is the same as in Example 1.

[0093] The rare earth-doped solid acid catalyst modified with ionic liquid prepared in this embodiment catalyzes the cumene peroxide solution under the same conditions as in Example 1. The calculated results are: cumene peroxide conversion rate of 71.2%, phenol selectivity of 82.5%, and acetone selectivity of 90.2%.

[0094] Example 8

[0095] This embodiment provides a method for preparing an ionic liquid modified rare earth doped solid acid catalyst. Except for the calcination temperature of 900°C in step (2), the preparation method is the same as in Example 1.

[0096] The rare earth-doped solid acid catalyst modified with ionic liquid prepared in this embodiment catalyzes the cumene peroxide solution under the same conditions as in Example 1. The calculated results are: cumene peroxide conversion rate of 63.4%, phenol selectivity of 78.2%, and acetone selectivity of 80.6%.

[0097] Example 9

[0098] This embodiment provides a method for preparing a rare-earth-doped solid acid catalyst modified with an ionic liquid, wherein the ionic liquid in step (3) is 1-n-pentanoic acid-3-methylimidazolium hydrogen sulfate [C4H8CO2HMIM]. + [Cl] - Except for the above, everything else is the same as in Example 1.

[0099] The rare earth-doped solid acid catalyst modified with ionic liquid prepared in this embodiment catalyzes the cumene peroxide solution under the same conditions as in Example 1. The calculated results are: cumene peroxide conversion rate of 92.1%, phenol selectivity of 94.2%, and acetone selectivity of 95.5%.

[0100] Example 10

[0101] This embodiment provides the application of an ionic liquid-modified rare earth-doped solid acid catalyst. 5.0 g of catalyst A prepared in Example 1 and 100 g of a 60% butylbenzene peroxide solution were placed in a four-necked flask and stirred at 35°C for 60 min. After the reaction, the catalyst was separated by cooling and filtration. A sample of the filtrate was analyzed by gas chromatography, and the results showed: butylbenzene peroxide conversion rate 99.9%, phenol selectivity 99.2%, and butyraldehyde selectivity 98.3%.

[0102] Example 11

[0103] This embodiment provides the application of an ionic liquid-modified rare earth-doped solid acid catalyst. 3.0 g of catalyst C prepared in Example 3 and 100 g of a propylbenzene solution containing 50% propylbenzene peroxide were placed in a four-necked flask and stirred at 45°C for 45 min. After the reaction, the temperature was lowered and the catalyst was separated by vacuum filtration. A sample of the filtrate was analyzed by gas chromatography, and the results showed that the propylbenzene peroxide conversion rate was 99.8%, the phenol selectivity was 99.5%, and the propionaldehyde selectivity was 98.9%.

[0104] In summary, the α-hydroperoxide cracking reaction using the rare earth-doped solid acid catalyst modified by the ionic liquid provided by this invention exhibits high conversion rate and product selectivity, and the catalyst can be easily separated and recovered, making it promising for large-scale application.

[0105] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. The use of an ionic liquid-modified rare earth-doped solid acid catalyst, characterized in that, Alkylbenzene α-hydroperoxide undergoes a contact reaction under the action of the rare earth-doped solid acid catalyst modified by the ionic liquid to generate phenol and ketone-aldehyde compounds. The resulting reaction solution is subjected to solid-liquid separation to recover the solid acid catalyst, and the filtrate is separated by distillation to obtain the target product. The preparation method of the ionic liquid-modified rare earth-doped solid acid catalyst includes the following steps: (1) After mixing the carrier salt solution and rare earth element salt, pH adjuster is added to adjust the pH, and the solution is subjected to static aging and first solid-liquid separation to obtain the first solid product; (2) The first solid material is subjected to crushing and roasting processes in sequence to obtain the second solid material; (3) The second solid is immersed in an ionic liquid and then subjected to ultrasonic treatment, second solid-liquid separation, washing and drying in sequence to obtain an ionic liquid modified rare earth doped solid acid catalyst. The carrier salt solution in step (1) includes any one or a combination of at least two of zirconium chloride solution, zirconium nitrate solution, zirconium sulfate solution, zirconium acetate solution, titanium chloride solution, titanium nitrate solution, titanium sulfate solution, or titanium acetate solution; The ionic liquid in step (3) comprises 1-alkyl-3-methylimidazolium salt [RMIM]. + [B] - N-alkylpyridine hydrogen sulfate [RPy] + [B] - 1-Carboxylic acid alkyl-3-methylimidazolium salt [ROOHMIM] + [B] - N-Carboxylic Alkylpyridine Hydrogen Sulfate [ROOHPy] + [B] - 1-Sulfonic acid alkyl-3-methylimidazolium salt [RSO3HMIM] + [B] - Or N-sulfonic acid alkylpyridine hydrogen sulfate [RSO3HPy] + [B] - In the ionic liquid, R is a C1-C6 alkyl group, and B is a combination of any one or at least two of the following: - It consists of hydrogen sulfate or hydrogen phosphate.

2. The use according to claim 1, characterized in that, The concentration of the carrier salt solution is 0.5-30%.

3. The use according to claim 1, characterized in that, The rare earth element salts include any one or a combination of at least two of cerium chloride, cerium nitrate, cerium sulfate, cerium acetate, lanthanum chloride, lanthanum nitrate, lanthanum sulfate, or lanthanum acetate.

4. The use according to claim 1, characterized in that, The liquid-to-solid ratio of the carrier salt solution to the rare earth element salt is 9.4~197000 mL / g.

5. The use according to claim 1, characterized in that, The pH adjuster in step (1) includes ammonia.

6. The use according to claim 5, characterized in that, The concentration of the ammonia water is 1-30%.

7. The use according to claim 1, characterized in that, Adjust the pH to 7-13.

8. The use according to claim 1, characterized in that, The settling and aging time is 12-48 hours.

9. The use according to claim 1, characterized in that, The roasting temperature in step (2) is 500~800℃.

10. The use according to claim 1, characterized in that, The roasting process takes 6 to 24 hours.

11. The use according to claim 1, characterized in that, Before impregnation in step (3), the second solid material is crushed to 0.01~2mm.

12. The use according to claim 1, characterized in that, The frequency of the ultrasonic treatment is 20~60KHz.

13. The use according to claim 1, characterized in that, The temperature of the ultrasonic treatment is 40~80℃.

14. The use according to claim 1, characterized in that, The duration of the ultrasonic treatment is 20 to 600 minutes.

15. The use according to claim 1, characterized in that, The preparation method includes the following steps: (1) Mix a carrier salt solution with a concentration of 0.5% to 30% and a rare earth element salt with a liquid-to-solid ratio of 9.4 to 197000 mL / g, then add ammonia water with a concentration of 1% to 30% to adjust the pH to 7 to 13, and then let it stand for 12 to 48 hours and separate the first solid and liquid to obtain the first solid. The carrier salt solution includes any one or a combination of at least two of zirconium chloride solution, zirconium nitrate solution, zirconium sulfate solution, zirconium acetate solution, titanium chloride solution, titanium nitrate solution, titanium sulfate solution, or titanium acetate solution; the rare earth element salt includes any one or a combination of at least two of cerium chloride, cerium nitrate, cerium sulfate, cerium acetate, lanthanum chloride, lanthanum nitrate, lanthanum sulfate, or lanthanum acetate. (2) The first solid material is subjected to crushing treatment and calcination treatment at a temperature of 500~800℃ for 6~24h to obtain the second solid material; (3) After crushing the second solid to 0.01~2mm, it is immersed in an ionic liquid and subjected to ultrasonic treatment at a frequency of 20~60KHz and a temperature of 40~80℃ for 20~600min, followed by solid-liquid separation, washing and drying to obtain an ionic liquid modified rare earth doped solid acid catalyst. The ionic liquid includes 1-alkyl-3-methylimidazolium salt [RMIM]. + [B] - N-alkylpyridine hydrogen sulfate [RPy] + [B] - 1-Carboxylic acid alkyl-3-methylimidazolium salt [ROOHMIM] + [B] - N-Carboxylic Alkylpyridine Hydrogen Sulfate [ROOHPy] + [B] - 1-Sulfonic acid alkyl-3-methylimidazolium salt [RSO3HMIM] + [B] - Or N-sulfonic acid alkylpyridine hydrogen sulfate [RSO3HPy] + [B] - In the ionic liquid, R is a C1-C6 alkyl group, and B is a combination of any one or at least two of the following: - It consists of hydrogen sulfate or hydrogen phosphate.

16. The use according to claim 1, characterized in that, The rare earth element doping amount of the ionic liquid modified rare earth doped solid acid catalyst is 0.1~10%.

17. The use according to claim 1, characterized in that, The general structural formula of the alkylbenzene α-hydroperoxide is as follows: In the formula, R1 and R2 represent alkyl groups of C0 to C6, and the dashed part indicates that the two groups R1 and R2 remain independent or are connected to form a ring.

18. The use according to claim 1, characterized in that, The concentration of alkylbenzene α-hydroperoxide in the contact reaction is 5-75%.

19. The use according to claim 1, characterized in that, The amount of rare earth-doped solid acid catalyst modified with ionic liquid in the contact reaction is 0.5-20%.

20. The use according to claim 1, characterized in that, The temperature of the contact reaction is 30~120℃.

21. The use according to claim 1, characterized in that, The contact reaction time is 10-120 min.

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