A shape-selective catalyst for preparing 4,4'-disubstituted diphenylmethane by alkylation and a preparation method and application thereof

Abstract

The application discloses a shape-selective catalyst for preparing 4,4'-disubstituted diphenylmethane by alkylation and a preparation method and application thereof. The catalyst is composed of a molecular sieve and an oxide for modifying the molecular sieve. The oxide is an oxide corresponding to the highest valence of a modified element. The modified element includes phosphorus, titanium, zirconium, gallium, indium, germanium, molybdenum, tungsten, rhenium or copper. The mass content of the oxide in the catalyst is 0.01-20% in the catalyst with a mass of 100%. The catalyst has good thermal stability and chemical stability, can be repeatedly used, has a simple regeneration method and a high activity recovery rate.

Description

Technical Field

[0001] This invention belongs to the field of shape-selective catalyst technology, specifically relating to a shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, its preparation method, and its application. Background Technology

[0002] 4,4'-Disubstituted diphenylmethanes are an important class of organic compounds. In their symmetrical structures, the 4,4'-position of the benzene ring is replaced by different groups, forming a variety of valuable derivatives. Typical 4,4'-disubstituted diphenylmethane compounds include: 4,4'-dimethyldiphenylmethane (used as an organic synthesis intermediate), 4,4'-diaminodiphenylmethane (used as an epoxy resin curing agent and also an intermediate in the synthesis of diphenylmethane diisocyanate (MDI), 4,4'-dichlorodiphenylmethane, and 4,4'-difluorodiphenylmethane (a key intermediate in the synthesis of high-performance engineering plastics such as polyether ketone (PEEK) and pharmaceuticals such as fluorobenzoquinone).

[0003] Currently, there are two main routes for the synthesis of 4,4'-disubstituted diphenylmethane:

[0004] The first route generally uses formaldehyde and substituted benzene as raw materials, which are condensed under acid catalysis to obtain the target product or precursor. Related patents mainly focus on the preparation and modification of solid acid catalysts, such as: solid superacids prepared from fly ash (CN102059129B), USY molecular sieves (CN101007767A), acid-modified activated carbon (CN107935864A), and cation exchange resins (CN109851509B). A common drawback of this route is its low product yield, difficulty in separation, and heavy pollution.

[0005] The second route uses substituted benzene and 4-substituted benzyl chloride as raw materials, and condenses them under acid catalysis to obtain the target product. For example, patent CN117384008A discloses a method for synthesizing 4,4'-dichlorodiphenylmethane by alkylation of chlorobenzene and 4-chlorobenzyl chloride with solid acid catalysis, similar to the method for synthesizing diphenylmethane by alkylation of benzene and benzyl chloride (CN102029171A, CN104496739A). The disadvantage of this type of method is that it produces hydrochloric acid gas as a byproduct, which causes great pollution, and the selectivity of the target product is low (<88%). Patent CN117902989A discloses a method for synthesizing 4,4'-diaminodiphenylmethane by catalytic reaction of aniline and 4-aminobenzyl alcohol. The catalyst is prepared by modification of metal-organic framework material UiO-66. The disadvantage of this method is that MOF catalysts are expensive and have poor stability, and are difficult to recover and regenerate.

[0006] Furthermore, when synthesizing 4,4'-disubstituted diphenylmethane using the above process route, 2,4'-disubstituted diphenylmethane or 3,4'-disubstituted diphenylmethane will inevitably be produced as byproducts. 4,4'-disubstituted diphenylmethane is an isomer of 2,4'-disubstituted diphenylmethane and 3,4'-disubstituted diphenylmethane, and their physical properties are quite similar, thus posing a problem of separation difficulties.

[0007] To improve the para-selectivity of alkylation reactions of substituted benzenes, shape-selective molecular sieves are generally used as catalysts. Patents CN106807442A and CN105646132A both employed modified molecular sieves in the catalytic alkylation of toluene to p-xylene, using methanol and dimethyl ether as alkylating agents. However, due to the low activity of methanol and dimethyl ether, the reaction temperatures were both above 300°C. High temperatures not only lead to low para-selectivity in the main alkylation reaction but also exacerbate methanol or dimethyl ether side reactions, such as methanol-to-olefins (MTO), methanol-to-aromatics (MTA), and coking reactions, resulting in low utilization of the alkylating agent. Furthermore, under high-temperature conditions, the water byproduct of methanol dehydration causes dealuminization of the catalyst framework and collapse of the pore structure, leading to irreversible catalyst deactivation.

[0008] In short, the shortcomings of existing alkylation technology are: (1) using halogenated hydrocarbons as alkylating agents will produce harmful hydrogen halides, which are highly corrosive; (2) using methanol and its ethers as alkylating agents will result in high reaction temperatures, many side reactions, and easy carbon deposition and deactivation of the catalyst, or even irreversible deactivation. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the present invention aims to provide a shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, its preparation method, and its application. This shape-selective catalyst selectively catalyzes the alkylation reaction of 4-substituted benzyl alcohol or 4-substituted benzyl ether at relatively low temperatures to produce the corresponding 4,4'-disubstituted diphenylmethane product. The reaction process is green and environmentally friendly, producing no toxic pollutants such as hydrogen chloride. The reactivity of the alkylating agent is precisely controlled by specific substituents on the benzene ring, resulting in high utilization of the alkylating agent and no side reactions. Furthermore, the catalyst exhibits high activity, high selectivity, good stability, and is easily separated, recovered, and regenerated, allowing for repeated use.

[0010] A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, the catalyst comprising a molecular sieve and an oxide modifying the molecular sieve, wherein the oxide is an oxide of the highest valence corresponding to the modifying element, and the modifying element includes phosphorus, titanium, zirconium, gallium, indium, germanium, molybdenum, tungsten, rhenium, or copper; the mass of the catalyst is 100%, the oxide accounts for 0.01-20% of the mass of the catalyst, and the balance is molecular sieve.

[0011] Preferably, the molecular sieve is one of ZSM-12, Beta, MOR, and Y molecular sieves, and the silica-alumina ratio of the molecular sieve is 3-200.

[0012] The method for preparing the shape-selective catalyst for alkylation to prepare 4,4'-disubstituted diphenylmethane is an ion exchange method, an impregnation method, or an in-situ hydrothermal synthesis method.

[0013] Preferably, the ion exchange method is as follows: the modified element precursor is dissolved in water to prepare a modified solution with a concentration of 0.1-1 mol / L, and the molecular sieve after ammonium exchange is added to it according to the liquid-solid ratio of (1-20) mL:1g. The solution is refluxed at 50-80℃ for 4-24h, filtered, washed with deionized water, dried, and calcined.

[0014] The impregnation method is as follows: Dissolve the modified element precursor in water to prepare a 0.1-1 mol / L modified solution, add the ammonium-exchanged molecular sieve to it according to the liquid-solid ratio of (1-20) mL:1g, reflux at 50-80℃ for 4-24h, heat up to evaporate the solvent, dry, and calcine.

[0015] The in-situ hydrothermal synthesis method is as follows: the template agent is mixed with water, and the modified element precursor diluted with ethanol is added dropwise. After the addition is complete, the mixture is stirred at room temperature for 10 min. The silicon source is added dropwise, and the mixture is stirred for another 30 min after the addition is complete. Then the aluminum source is added, and the mixture is stirred evenly. The pH of the system is controlled to be 10-12. The target molecular sieve seed crystals are then added, and the mixture is aged at room temperature for 4-24 h. The mixture is then transferred to a crystallization vessel and crystallized at 110-200℃ for 2-7 days. After centrifugation, the mixture is washed until neutral, dried, calcined, and finally subjected to ammonium exchange.

[0016] Preferably, the crystallization reactor rotates at a speed of less than or equal to 10 rpm; the crystallization heating rate is 2-15℃ / min.

[0017] Preferably, the ammonium exchange is performed as follows: the ammonium salt solution is mixed with the raw material to be exchanged at a liquid-solid ratio of (1-20) mL:1g, refluxed at 50-80℃ for 4-24h, filtered, washed until neutral, and dried; this operation is repeated 3 times, and then calcined to complete the ammonium exchange; the concentration of the ammonium salt is 0.1-1mol / L, and the ammonium salt is one of ammonium chloride, ammonium nitrate, ammonium sulfate, ammonium carbonate, and ammonium bicarbonate.

[0018] Preferably, the drying is performed at 80-120℃ for 12-48 hours, and the calcination is performed at 450-600℃ in air for 4-24 hours.

[0019] Preferably, in the in-situ hydrothermal synthesis method, the molar amounts of silicon source and aluminum source are calculated as SiO2 and Al2O3, respectively; the molar ratio of silicon source, modifying element, template agent, and water is 1 : 0.01-0.05 : 0.15-0.25 : 10-30; the molar ratio of silicon source to aluminum source is 3-200; and the seed crystal accounts for ≤5% of the mass content of silicon source.

[0020] Preferably, the template agent is at least one of tetraethylammonium hydroxide, polyallyldimethylammonium chloride, L-lysine, methyltriethylammonium bromide, tetrapropylammonium hydroxide, hexamethylenediamine, and hexamethylenetetrammonium; the silicon source is silica sol or tetraethyl silicate; and the aluminum source is one of sodium aluminate, aluminum sulfate, aluminum nitrate, and aluminum isopropoxide.

[0021] Preferably, the precursor of the modified element is as follows: when the modified element is phosphorus, the corresponding precursor is ammonium dihydrogen phosphate; when the modified element is titanium, the corresponding precursor is tetrabutyl titanate, titanium ammonia complex [Ti(NH3)6]Cl4, titanium nitrate, or titanium sulfate; when the modified element is zirconium, gallium, indium, or germanium, the corresponding precursor is the nitrate or sulfate of the modified element; when the modified element is molybdenum, the corresponding precursor is ammonium molybdate (NH4)2MoO4; when the modified element is tungsten, the corresponding precursor is ammonium tungstate hydrate; when the modified element is rhenium, the corresponding precursor is ammonium perrhenate; when the modified element is copper, the corresponding precursor is copper chloride, copper nitrate hexahydrate, or copper sulfate.

[0022] A method for preparing 4,4'-disubstituted diphenylmethane is as follows: substituted benzene and catalyst are sequentially added to a batch reactor, the reactor is purged with nitrogen three times, the catalyst is stirred to suspend it, an alkylating agent dissolved in a solvent is added, and the reactor is stirred for 0.5-48 h at a reaction temperature of -20℃ to 200℃ and a reaction pressure of 0.1-3 MPa. The reactor is then filtered, the filtrate is collected, and the catalyst is recovered.

[0023] The alkylating agent is 4-substituted benzyl alcohol, 4-substituted benzyl methyl ether, or di(4-substituted benzyl) ether;

[0024] The substituents in the alkylating agent correspond to the same substituents in the substituted benzene in the starting material, and the substituents include any one of -F, -Cl, -Br, -I, -NO2, -NH2 or -CH3;

[0025] The catalyst is the catalyst described above.

[0026] Preferably, the molar ratio of the raw material substituted benzene to the alkylating agent is 1-5; the molar ratio of the solvent to the alkylating agent is 1-5; the mass ratio of the catalyst to the alkylating agent is 0.01-0.2; the solvent is 1,2-dichloroethane, dichloromethane, or solvent substituted benzene; and the solvent substituted benzene is the same as the raw material substituted benzene.

[0027] Preferably, when preparing 4,4'-disubstituted diphenylmethane, the stirring speed is 100-600 rpm.

[0028] Preferably, after the catalyst is recovered, it can be dried at 80-120℃ for 12-48 hours and then reused. After several uses, it can be regenerated by means of the following method: first, elute with an elution solvent at 40-80℃ for 2-8 hours, then soak in a 1-10wt% dilute acid solution for 2-12 hours, then wash with deionized water until neutral, and then vacuum dry at 40-80℃ for 12-24 hours.

[0029] Preferably, the elution solvent is acetone or toluene, and the dilute acid solution is dilute sulfuric acid or dilute hydrochloric acid.

[0030] Preferably, the catalyst needs to be regenerated when either of the following conditions is met: product selectivity is less than 80% or yield is less than 70%.

[0031] Preferably, the regenerated catalyst has a yield recovery rate of ≥95%; otherwise, it cannot be recycled again.

[0032] Advantages of this invention:

[0033] (1) The catalyst provided by the present invention has good thermal stability and good chemical stability, can be reused, has a simple regeneration method, and has a high activity recovery rate;

[0034] (2) 4,4'-disubstituted diphenylmethane is prepared by alkylating substituted benzyl alcohol, 4-substituted benzyl methyl ether or di(4-substituted benzyl) ether with substituted benzyl alcohol, 4-substituted benzyl methyl ether or di(4-substituted benzyl) ether as alkylating agents with substituted benzyl benzyl alcohol. This process does not produce toxic gases such as hydrogen chloride, has low corrosiveness to equipment, mild reaction conditions, high selectivity of target products, and is convenient for separation and recovery. Detailed Implementation

[0035] In this invention, IE is short for Ion Exchange Method, representing the ion exchange method; Im is short for Impregnation Method, representing the impregnation method; and HS is short for in situ Hydrothermal Synthesis Method, representing the in situ hydrothermal synthesis method.

[0036] Example 1: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising ZSM-12 molecular sieve and CuO modified with the molecular sieve; the mass of the catalyst is 100%, the mass content of CuO is 0.1% of the catalyst, and the balance is molecular sieve; the silica-alumina ratio of the molecular sieve is 30;

[0037] The catalyst is prepared by ion exchange, as follows:

[0038] (1) Ammonium exchange: Mix 1 mol / L ammonium salt solution with ZSM-12 molecular sieve at a liquid-solid ratio of 10 mL: 1 g, reflux at 80 °C for 4 h, filter, wash until neutral, and dry at 120 °C for 12 h; repeat this operation 3 times to complete the ammonium exchange; then calcine at 550 °C for 6 h in flowing air;

[0039] (2) Ion exchange: Dissolve copper nitrate hexahydrate in water to prepare a 1 mol / L modified solution. Add the ammonium-exchanged molecular sieve to it according to a liquid-solid ratio of 20 mL: 1 g. Reflux at 80 °C for 4 h, filter, wash with deionized water to remove free ions, dry at 120 °C for 12 h, and calcine at 550 °C for 6 h in flowing air to obtain the catalyst, which is denoted as 0.1% CuO / ZSM-12 (IE).

[0040] Example 2: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising ZSM-12 molecular sieve and CuO modified with the molecular sieve; the mass of the catalyst is 100%, the CuO accounts for 20% of the mass of the catalyst, and the balance is molecular sieve; the silica-alumina ratio of the molecular sieve is 30;

[0041] The catalyst is prepared by impregnation, as follows:

[0042] (1) Ammonium exchange: Same as step (1) in Example 1;

[0043] (2) Impregnation: Dissolve copper nitrate hexahydrate in water to prepare a 1 mol / L modified solution. Add the ammonium-exchanged molecular sieve to it according to the liquid-solid ratio of 20 mL: 1 g. Reflux at 80 °C for 4 h, filter, heat to 100 °C to evaporate the solvent, dry at 120 °C for 12 h, and calcine at 550 °C for 6 h in flowing air to obtain the catalyst, which is denoted as 20% CuO / ZSM-12 (Im).

[0044] Example 3: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising ZSM-12 molecular sieve and TiO2 modified with the molecular sieve; the mass of the catalyst is 100%, the TiO2 accounts for 5% of the mass of the catalyst, and the balance is molecular sieve; the silica-alumina ratio of the molecular sieve is 30;

[0045] The catalyst was prepared by in-situ hydrothermal synthesis, as follows:

[0046] Tetrapropylammonium hydroxide (TPAOH) was mixed with water as a template agent. Tetrabutyl titanate, a modified element precursor diluted with ethanol, was added dropwise. After the addition was complete, the mixture was stirred at room temperature for 10 minutes. Then, 30 wt% silica sol was added dropwise as a silicon source. After the addition was complete, stirring continued for 30 minutes. Aluminum sulfate was then added as an aluminum source. After thorough mixing, the pH was controlled at 12. ZSM-12 molecular sieve seed crystals were then added, and the mixture was aged at room temperature for 24 hours with stirring to form a homogeneous gel. Transfer... The mixture was transferred to a crystallization vessel and heated to 150°C at a rate of 2°C / min for 7 days. The rotation speed of the crystallization vessel was 0.5 rpm. Then, it was centrifuged, washed until neutral, dried at 80°C for 48 hours, calcined at 550°C in flowing air for 4 hours, and finally subjected to ammonium exchange, which was the same as step (1) in Example 1. The molar amounts of the silicon source and aluminum source were SiO2 and Al2O3, respectively. The molar ratio of the silicon source, modified element titanium, template agent, and water was 1:0.05:0.25:30. The molar ratio of the silicon source and aluminum source was 30. The mass of the molecular sieve seed crystal was 5% of the mass of the silicon source.

[0047] The resulting catalyst is designated as 5%TiO2 / ZSM-12 (HS).

[0048] Example 4: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising ZSM-12 molecular sieve and ZrO2 modified with the molecular sieve; the mass of the catalyst is 100%, the ZrO2 accounts for 0.5% of the mass of the catalyst, and the balance is molecular sieve; the silica-alumina ratio of the molecular sieve is 200;

[0049] In the preparation method, the molar ratio of silicon source, modified element zirconium, template agent and water is 1:0.01:0.15:30, and the molar ratio of silicon source and aluminum source is 200. Zirconium nitrate is used instead of tetrabutyl titanate as the modified element precursor. The crystallization temperature is 170℃ and the heating rate is 15℃ / min. Other aspects are the same as in Example 3. The resulting catalyst is denoted as 0.5%ZrO2 / ZSM-12(HS).

[0050] Example 5: The molecular sieve is a Beta molecular sieve. In the preparation method, the template agent is tetraethylammonium hydroxide (TEAOH), the rotation speed of the crystallization vessel is 10 rpm, the seed crystal is a Beta molecular sieve seed crystal, and the rest is the same as in Example 3. The obtained catalyst is denoted as 5%TiO2 / Beta (HS).

[0051] Example 6: The molecular sieve is a Beta molecular sieve. In the preparation method, the template agent is a mixture of tetraethylammonium hydroxide (TEAOH), polyallyl dimethylammonium chloride (PDDA), and L-lysine in a molar ratio of 0.1:0.05:0.05. The molar ratio of silicon source, modified element titanium, template agent, and water is 1:0.05:0.2:30. The seed crystal is a Beta molecular sieve seed crystal. Other steps are the same as in Example 3. The obtained catalyst is denoted as 5%TiO2 / Beta (HS).

[0052] Example 7: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising a MOR molecular sieve and TiO2 modified from the molecular sieve; the mass of the catalyst is 100%, the TiO2 accounts for 5% of the mass of the catalyst, and the balance is the molecular sieve; the silica-alumina ratio of the molecular sieve is 20;

[0053] The catalyst was prepared by in-situ hydrothermal synthesis, as follows:

[0054] A mixture of tetraethylammonium hydroxide (TEAOH), methyltriethylammonium bromide (MTEABr), and hexamethylenediamine in a molar ratio of 0.15:0.05:0.05 was used as a template agent and mixed with water. Tetrabutyl titanate, a modified element precursor diluted with ethanol, was added dropwise. After the addition was complete, the mixture was stirred at room temperature for 10 minutes. Tetraethyl orthosilicate was then added dropwise as a silicon source. After the addition was complete, stirring continued for 30 minutes. Aluminum isopropoxide was then added as an aluminum source. After thorough mixing, the pH was controlled at 10, and MOR molecular sieve seed crystals were added. The mixture was then aged at room temperature for 12 hours to form… A uniform gel-like substance was transferred to a crystallization vessel and crystallized at 160°C for 2 days at a heating rate of 2°C / min. The rotation speed of the crystallization vessel was 10 rpm. Then, it was centrifuged, washed until neutral, dried at 80°C for 48 hours, calcined at 550°C for 6 hours in flowing air, and finally subjected to ammonium exchange, which was the same as step (1) in Example 1. The molar amounts of the silicon source and aluminum source were calculated as SiO2 and Al2O3, respectively. The molar ratio of the silicon source, modified element titanium, template agent, and water was 1:0.05:0.25:30. The molar ratio of the silicon source and aluminum source was 20. The amount of seed crystal added was 5% of the mass of the silicon source.

[0055] The resulting catalyst is denoted as 5%TiO2 / MOR(HS).

[0056] Example 8: The molecular sieve is a Y molecular sieve with a silicon-to-aluminum ratio of 20. In the preparation method, the template agent is hexamethylenetetraammonium (HMTA), the seed crystal is a Y molecular sieve seed crystal, crystallization is carried out at 110°C for 3 days, the rotation speed of the crystallization vessel is 0, the molar ratio of silicon source to aluminum source is 20, the amount of seed crystal added is 1% of the mass of silicon source, and the rest is the same as in Example 3. The resulting catalyst is denoted as 5%TiO2 / Y (HS).

[0057] Example 9: GeO2 was used instead of TiO2, and germanium nitrate Ge(NO3)3 was used as the modified element precursor. Everything else was the same as in Example 3. The resulting catalyst was denoted as 5% GeO2 / ZSM-12 (HS).

[0058] A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane comprises a ZSM-12 molecular sieve and GeO2 modified with the molecular sieve; the mass of the catalyst is 100%, the GeO2 accounts for 5% of the mass of the catalyst, and the balance is the molecular sieve; the silica-alumina ratio of the molecular sieve is 30.

[0059] The catalyst was prepared by in-situ hydrothermal synthesis, as follows:

[0060] Tetrapropylammonium hydroxide (TPAOH) was used as a template agent and mixed with water. Germanium nitrate (Ge(NO3)3) diluted with ethanol was added dropwise. After the addition was complete, the mixture was stirred at room temperature for 10 min. 30 wt% silica sol was added dropwise as a silicon source. After the addition was complete, the mixture was stirred for another 30 min. Then aluminum sulfate was added as an aluminum source. After stirring evenly, the pH value was controlled at 10. ZSM-12 molecular sieve seed crystals were added. The mixture was stirred and aged at room temperature for 4 h to form a uniform gel. The sample was transferred to a crystallization vessel and heated to 200°C at a rate of 2°C / min for 7 days. The rotation speed of the crystallization vessel was 0.5 rpm. Then, it was centrifuged, washed until neutral, dried at 80°C for 48 hours, calcined at 550°C in flowing air for 4 hours, and finally subjected to ammonium exchange, which was the same as step (1) in Example 1. The molar amounts of the silicon source and aluminum source were SiO2 and Al2O3, respectively. The molar ratio of the silicon source, modified element titanium, template agent, and water was 1:0.05:0.25:30, and the molar ratio of the silicon source and aluminum source was 30. The mass of the molecular sieve seed crystal was 1% of the mass of the silicon source.

[0061] The resulting catalyst is designated as 5% GeO2 / ZSM-12 (HS).

[0062] Example 10: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising a Beta molecular sieve and Ga2O3 modified from the molecular sieve; the mass of the catalyst is 100%, the Ga2O3 accounts for 0.3% of the mass of the catalyst, and the balance is the molecular sieve; the silica-alumina ratio of the molecular sieve is 50;

[0063] In the preparation method, the corresponding modified element precursor is gallium nitrate nonahydrate Ga(NO3)3·9H2O, the molecular sieve is Beta molecular sieve, and the rest is the same as in Example 1. The obtained catalyst is recorded as 0.3wt% Ga2O3 / Beta(IE).

[0064] Example 11: In the catalyst, In2O3 was used instead of Ga2O3, and the corresponding modified element precursor was indium nitrate pentahydrate In(NO3)3·5H2O. Everything else was the same as in Example 10. The resulting catalyst was denoted as 0.3wt% In2O3 / Beta (IE).

[0065] Example 12: In the catalyst, GeO2 was used instead of Ga2O3, and the corresponding modified element precursor was germanium nitrate Ge(NO3)3. Everything else was the same as in Example 10. The resulting catalyst was denoted as 0.3wt% GeO2 / Beta(IE).

[0066] Example 13: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising a MOR molecular sieve and CuO modified with the molecular sieve; the catalyst is 100% by mass, the CuO accounts for 0.3% of the catalyst by mass, and the balance is the molecular sieve; the silica-alumina ratio of the molecular sieve is 3;

[0067] The catalyst is prepared by ion exchange, as follows:

[0068] (1) Ammonium exchange: Mix 0.1 mol / L ammonium salt solution with MOR molecular sieve at a liquid-solid ratio of 20 mL: 1 g, reflux at 50 °C for 24 h, filter and wash until neutral, and dry at 80 °C for 48 h; repeat this operation 3 times to complete the ammonium exchange; then calcine at 450 °C for 24 h in flowing air;

[0069] (2) Ion exchange: Dissolve copper sulfate in water to prepare a modified solution of 0.1 mol / L. Add the molecular sieve after ammonium exchange according to the liquid-solid ratio of 1 mL: 1 g. Reflux at 50 °C for 24 h, filter, wash with deionized water to remove free ions, dry at 80 °C for 48 h, and calcine at 450 °C for 24 h in flowing air to obtain the catalyst, which is recorded as 0.3 wt% CuO / MOR (IE).

[0070] Example 14: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising a Y molecular sieve and CuO modified with the molecular sieve; the mass of the catalyst is 100%, the CuO accounts for 0.3% of the mass of the catalyst, and the balance is the molecular sieve; the silica-alumina ratio of the molecular sieve is 10;

[0071] In the preparation method, the corresponding modified element precursor is copper chloride, the molecular sieve is Y molecular sieve, and the rest is the same as in Example 1. The obtained catalyst is recorded as 0.3wt% CuO / Y (IE).

[0072] Example 15: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising a Beta molecular sieve and ReO2 modified from the molecular sieve; the mass of the catalyst is 100%, the ReO2 accounts for 1% of the mass of the catalyst, and the balance is the molecular sieve; the silica-alumina ratio of the molecular sieve is 25;

[0073] (1) Ammonium exchange: Mix 0.1 mol / L ammonium salt solution with Beta molecular sieve at a liquid-solid ratio of 1 mL: 1 g, reflux at 60 °C for 12 h, filter and wash until neutral, and dry at 100 °C for 24 h; repeat this operation 3 times to complete the ammonium exchange; then calcine at 600 °C for 4 h in flowing air;

[0074] (2) Impregnation: Dissolve ammonium perrhenate in water to prepare a 0.1 mol / L modified solution. Add the ammonium-exchanged molecular sieve to it according to the liquid-solid ratio of 1 mL: 1 g. Reflux at 50 °C for 24 h, filter, heat to 100 °C to evaporate the solvent, dry at 80 °C for 48 h, and calcine at 600 °C in flowing air for 4 h to obtain the catalyst, which is recorded as 1 wt% ReO2 / Beta (Im).

[0075] Example 16: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising a Beta molecular sieve and TiO2 modified thereon; the catalyst is 100% by mass, the TiO2 accounts for 10% of the catalyst by mass, and the balance is the molecular sieve; the silica-alumina ratio of the molecular sieve is 25;

[0076] In the preparation method, the corresponding modified element precursor is titanium ammonia complex [Ti(NH3)6]Cl4, the molecular sieve is Beta molecular sieve, and the rest is the same as in Example 2. The obtained catalyst is recorded as 10wt% TiO2 / Beta (Im).

[0077] Example 17: In the catalyst, Ga2O3 was used instead of TiO2, and the corresponding modified element precursor was gallium nitrate nonahydrate Ga(NO3)3·9H2O. Everything else was the same as in Example 16. The resulting catalyst was denoted as 10wt% Ga2O3 / Beta (Im).

[0078] Example 18: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising a MOR molecular sieve and TiO2 modified thereon; the mass of the catalyst is 100%, the TiO2 accounts for 10% of the mass of the catalyst, and the balance is the molecular sieve; the silica-alumina ratio of the molecular sieve is 30.

[0079] In the preparation method, the corresponding modified element precursor is titanium nitrate, the molecular sieve is MOR molecular sieve, and the rest is the same as in Example 2. The obtained catalyst is recorded as 10wt% TiO2 / MOR (Im).

[0080] Example 19: Y molecular sieve with a silicon-to-aluminum ratio of 30 was used instead of MOR molecular sieve. The rest was the same as in Example 18. The resulting catalyst was denoted as 10wt% TiO2 / Y (Im).

[0081] Example 20: A shape-selective catalyst for the alkylation preparation of 4,4'-disubstituted diphenylmethane, comprising a MOR molecular sieve and ZrO2 modified from the molecular sieve; the mass of the catalyst is 100%, the ZrO2 accounts for 10% of the mass of the catalyst, and the balance is the molecular sieve; the silica-alumina ratio of the molecular sieve is 3;

[0082] In the preparation method, the corresponding modified element precursor is zirconium nitrate, the molecular sieve is MOR molecular sieve, the silicon-to-aluminum ratio is 3, and the rest is the same as in Example 2. The resulting catalyst is denoted as 10wt% ZrO2 / MOR (Im).

[0083] Example 21: The CuO content of the catalyst was 0.01% by mass, and the rest was the same as in Example 2. The resulting catalyst was denoted as 0.01%CuO / ZSM-12 (Im).

[0084] Example 22: A method for preparing 4,4'-difluorodiphenylmethane, comprising the following steps: Substituted benzene and the catalyst described in Example 1 are sequentially added to a batch reactor, the reactor is purged with nitrogen three times, and the catalyst is stirred to suspend it. Then, an alkylating agent dissolved in a solvent is added to the reactor, and the reactor is stirred for 30 minutes at a reaction temperature of 200°C and a reaction pressure of 0.1 MPa at a stirring speed of 100 rpm. The reactor is then filtered, the filtrate is collected, and the catalyst is recovered.

[0085] The substituted benzene in the raw material is fluorobenzene; the alkylating agent is 4-fluorobenzyl alcohol; and the solvent is fluorobenzene.

[0086] The molar ratio of the substituted benzene to the alkylating agent is 1; the molar ratio of the solvent to the alkylating agent is 1; and the mass ratio of the catalyst to the alkylating agent is 0.2.

[0087] After the catalyst is recovered, it is dried at 80°C for 48 hours and put back into use. When the product selectivity is less than 80% or the yield is less than 70%, it is regenerated. The regeneration method is as follows: first, elute with acetone at 40°C for 8 hours, then soak in 1wt% dilute sulfuric acid solution for 2 hours, then wash with deionized water until neutral, and vacuum dry at 40°C for 24 hours.

[0088] The conversion rate of the alkylating agent, the product yield, and the activity recovery rate after catalyst regeneration were determined, and the results are shown in Table 1.

[0089] Example 23: In the preparation of 4,4'-difluorodiphenylmethane, the molar ratio of the substituted benzene to the alkylating agent was 5; the molar ratio of the solvent to the alkylating agent was 5; the mass ratio of the catalyst to the alkylating agent was 0.01; the solvent was 1,2-dichloroethane; the reaction was carried out at a reaction temperature of -20°C and a reaction pressure of 3 MPa for 48 h with stirring at a stirring speed of 600 rpm.

[0090] During catalyst regeneration, toluene was used instead of acetone as the elution solvent, and dilute hydrochloric acid was used instead of dilute sulfuric acid as the dilute acid solution. The rest was the same as in Example 22. The results are shown in Table 1.

[0091] Example 24: The alkylating agent was di(4-fluorobenzyl) ether, and everything else was the same as in Example 22. The results are shown in Table 1.

[0092] Example 25: The alkylating agent was 4-fluorobenzyl methyl ether, and the rest was the same as in Example 22. The results are shown in Table 1.

[0093] Example 26: The raw material substituted benzene is chlorobenzene, the alkylating agent is 4-chlorobenzyl alcohol, and 4,4'-dichlorodiphenylmethane is prepared. The catalyst used is the catalyst described in Example 3, and the rest is the same as in Example 22. The results are shown in Table 1.

[0094] Example 27: The raw material substituted benzene is bromobenzene, the alkylating agent is 4-bromobenzyl alcohol, and 4,4'-dibromodiphenylmethane is prepared. The catalyst used is the catalyst described in Example 3, and the rest is the same as in Example 22. The results are shown in Table 1.

[0095] Example 28: The raw material substituted benzene was iodobenzene, and the alkylating agent was 4-iodobenzyl alcohol. 4,4'-Diiododiphenylmethane was prepared. The catalyst used was the catalyst described in Example 3. Other aspects were the same as in Example 22. The results are shown in Table 1.

[0096] Example 29: The raw material substituted benzene is nitrobenzene, the alkylating agent is 4-nitrobenzyl alcohol, and 4,4'-dinitrodiphenylmethane is prepared. The catalyst used is the catalyst described in Example 3, and the rest is the same as in Example 22. The results are shown in Table 1.

[0097] Example 30: The raw material substituted benzene is aniline, the alkylating agent is 4-aminobenzyl alcohol, and 4,4'-diaminodiphenylmethane is prepared. The catalyst used is the catalyst described in Example 3, and the rest is the same as in Example 22. The results are shown in Table 1.

[0098] Example 31: The raw material substituted benzene is toluene, the alkylating agent is 4-methylbenzyl alcohol, and 4,4'-dimethyldiphenylmethane is prepared. The catalyst used is the catalyst described in Example 3. Other aspects are the same as in Example 22. The results are shown in Table 1.

[0099] Example 32: The catalysts of Examples 2-21 were used respectively, and the rest was the same as in Example 22. The results are shown in Table 2.

[0100] Comparative Example 1: The catalyst used was ZSM-12 molecular sieve with a silicon-to-aluminum ratio of 30. Other aspects were the same as in Example 26. The results are shown in Table 1.

[0101] Comparative Example 2: The catalyst used was a Beta molecular sieve with a silicon-to-aluminum ratio of 30. Other aspects were the same as in Example 26. The results are shown in Table 1.

[0102] Comparative Example 3: The catalyst used was a Y molecular sieve with a silicon-to-aluminum ratio of 30. Other aspects were the same as in Example 26. The results are shown in Table 1.

[0103] Table 1 Reaction Results

[0104] ;

[0105] Where X represents the conversion rate of the alkylating agent, expressed as % .

[0106] Y1 represents the product yield during the first use of the catalyst, expressed as % .

[0107] Y 再生 The product yield is expressed as % when the regenerated catalyst is used for the first time.

[0108] Z represents the activity recovery rate of the catalyst during its first use after regeneration, expressed as a percentage (%), i.e., Z = Y. 再生 / Y1.

[0109] Table 2 Reaction results of Example 32

[0110] .

Claims

1. A method for preparing 4,4'-disubstituted diphenylmethane, characterized in that: The method is as follows: Substituted benzene and catalyst are sequentially added to a batch reactor, nitrogen is purged three times, the catalyst is stirred to suspend it, and then an alkylating agent dissolved in a solvent is added. The reaction is stirred for 0.5-48 hours at a reaction temperature of -20℃ to 200℃ and a reaction pressure of 0.1-3MPa. The mixture is then filtered, the filtrate is collected, and the catalyst is recovered. The alkylating agent is 4-substituted benzyl alcohol, 4-substituted benzyl methyl ether, or di(4-substituted benzyl) ether; The substituents in the alkylating agent correspond to the same substituents in the substituted benzene in the starting material, and the substituents include any one of -F, -Cl, -Br, -I, -NO2, -NH2 or -CH3; The catalyst is composed of a molecular sieve and an oxide that modifies the molecular sieve. The oxide is the oxide of the highest oxidation state of the corresponding modifying element. The modifying element includes phosphorus, titanium, zirconium, gallium, indium, germanium, molybdenum, tungsten, rhenium, or copper. The mass of the catalyst is 100%, and the oxide accounts for 0.01-20% of the mass of the catalyst, with the balance being the molecular sieve.

2. The method for preparing 4,4'-disubstituted diphenylmethane according to claim 1, characterized in that: The molecular sieve is one of ZSM-12, Beta, MOR, and Y molecular sieves, and the silica-alumina ratio of the molecular sieve is 3-200.

3. The method for preparing 4,4'-disubstituted diphenylmethane according to claim 1, characterized in that: The catalyst is prepared by ion exchange, impregnation, or in-situ hydrothermal synthesis.

4. The method for preparing 4,4'-disubstituted diphenylmethane according to claim 3, characterized in that: The ion exchange method is as follows: Dissolve the modified element precursor in water to prepare a modified solution of 0.1-1 mol / L, add the molecular sieve after ammonium exchange according to the liquid-solid ratio of (1-20) mL:1g, reflux at 50-80℃ for 4-24h, filter, wash with deionized water, dry, and calcine. The impregnation method is as follows: Dissolve the modified element precursor in water to prepare a modified solution with a concentration of 0.1-1 mol / L. Add the ammonium-exchanged molecular sieve to it according to the liquid-solid ratio of (1-20) mL:1g. Reflux at 50-80℃ for 4-24h, heat up to evaporate the solvent, dry, and calcine. The in-situ hydrothermal synthesis method is as follows: the template agent is mixed with water, and the modified element precursor diluted with ethanol is added dropwise. After the addition is complete, the mixture is stirred at room temperature for 10 min. The silicon source is added dropwise. After the addition is complete, the mixture is stirred for another 30 min. Then the aluminum source is added and stirred evenly. The pH value of the system is controlled at 10-12. The target molecular sieve seed crystals are then added and the mixture is aged at room temperature for 4-24 h. Transfer to a crystallization kettle, crystallize at 110-200℃ for 2-7 days, centrifuge, wash until neutral, dry, calcine, and finally perform ammonium exchange.

5. The method for preparing 4,4'-disubstituted diphenylmethane according to claim 4, characterized in that: The ammonium exchange is performed as follows: the ammonium salt solution is mixed with the raw material to be exchanged at a liquid-solid ratio of (1-20) mL:1g, refluxed at 50-80℃ for 4-24h, filtered, washed until neutral, and dried; this operation is repeated 3 times, and then calcined to complete the ammonium exchange; the concentration of the ammonium salt is 0.1-1mol / L, and the ammonium salt is one of ammonium chloride, ammonium nitrate, ammonium sulfate, ammonium carbonate, and ammonium bicarbonate.

6. The method for preparing 4,4'-disubstituted diphenylmethane according to claim 4 or 5, characterized in that: The drying process involves drying at 80-120℃ for 12-48 hours, and the calcination process involves calcining in air at 450-600℃ for 4-24 hours.

7. The method for preparing 4,4'-disubstituted diphenylmethane according to claim 4, characterized in that: In the in-situ hydrothermal synthesis method, the molar amounts of silicon source and aluminum source are calculated as SiO2 and Al2O3, respectively. The molar ratio of silicon source, modifying element, template agent and water is 1 : 0.01-0.05 : 0.15-0.25 : 10-30. The molar ratio of silicon source to aluminum source is 3-200. The seed crystal accounts for ≤5% of the mass content of silicon source.

8. The method for preparing 4,4'-disubstituted diphenylmethane according to claim 4, characterized in that: The template agent is at least one of tetraethylammonium hydroxide, polyallyldimethylammonium chloride, L-lysine, methyltriethylammonium bromide, tetrapropylammonium hydroxide, hexamethylenediamine, and hexamethylenetetrammonium; the silicon source is silica sol or tetraethyl silicate; and the aluminum source is one of sodium aluminate, aluminum sulfate, aluminum nitrate, and aluminum isopropoxide.

9. The method for preparing 4,4'-disubstituted diphenylmethane according to claim 1, characterized in that: The molar ratio of the substituted benzene to the alkylating agent is 1-5; the molar ratio of the solvent to the alkylating agent is 1-5; the mass ratio of the catalyst to the alkylating agent is 0.01-0.2; the solvent is 1,2-dichloroethane, dichloromethane, or solvent substituted benzene; the solvent substituted benzene is the same as the substituted benzene in the raw material.