Preparation method of H12MDA with low trans-trans isomer content and used catalyst

Abstract

The invention relates to a preparation method of H12MDA with low trans-trans isomer content and a catalyst used in the preparation method. The catalyst is a supported catalyst and comprises a silicon-aluminum amorphous carrier and an active component, the silicon-aluminum amorphous carrier has a micropore, mesopore and macropore structure and is prepared by carrying out hydrothermal reaction on raw materials comprising an aluminum source and a silicon source in the presence of a template agent, and the template agent is selected from 4, 4-diaminodiphenyl-methane and 2, 4-diaminodiphenyl-methane or 2, 4-diaminodiphenyl-methane or 2, 4-diaminodiphenyl-methane or 2, 4-diaminodiphenyl-methane or 2, 4-diaminodiphenyl-methane or 2, 4-diaminodiphenyl-methane or 2, 4-diaminodiphenyl-methane. The catalyst is one or a combination of two of 1, 4-diaminodiphenylmethane. The catalyst is long in service life and excellent in stability, the yield of an H12MDA target product can be increased, the content of trans-isomers in the product is reduced, and the preparation process is also simple. The invention also provides a method for preparing H12MDA through MDA catalytic hydrogenation, and the method can improve the yield of the H12MDA product and obviously reduce the content of trans-isomers in the product.

Description

Technical Field

[0001] The invention relates to a preparation method of H12MDA with low trans-isomer content and a catalyst used therein. Background Art

[0002] 4,4'-Diaminodicyclohexylmethane (abbreviated as H12MDA or PACM in English) is an important organic intermediate, mainly used as a raw material for the production of epoxy curing agent and dicyclohexylmethane diisocyanate (H12MDI) in the polyurethane industry. H12MDI is obtained by phosgenation of H12MDA. This type of isocyanate molecule does not contain aromatic rings, so it has stable performance, strong antioxidant ability, and a wide range of applications. It is used to prepare lightweight, high-performance polyurethane coatings and paints. Since H12MDA has two cyclohexyl rings, each of which exists in cis or trans form, it exists in trans-trans Cis-trans Shun Shun Three stereoisomers with different thermodynamic properties. In equilibrium, trans-trans accounts for 50%, cis-trans accounts for 43%, and cis-cis accounts for 7%, among which the trans-trans isomer is the most thermodynamically stable. The composition ratio of the three stereoisomers determines the properties and uses of H12MDA and its subsequent products. H12MDA with an anti-trans isomer content of about 24% or less is called H12MDA-20, which is used to synthesize high-quality transparent polyurethane. The lower the content of anti-trans isomers, the better the product performance. Since H12MDA isomers are difficult to separate, the current research focus is to directly obtain stable H12MDA-20 during synthesis.

[0003] H12MDA is prepared by high temperature and high pressure reaction with 4,4'-diamino-diphenylmethane (MDA) as raw material under the action of catalyst. However, due to the stability of aromatic rings and steric hindrance effect, hydrogenation of MDA needs to destroy the large π bond of two benzene rings, which is difficult and the reaction conditions are harsh. At the same time, side reactions such as deamination and polymerization will occur during the hydrogenation process. Therefore, the production of H12MDA-20 through MDA hydrogenation reaction requires high-performance catalysts to increase the reaction rate and allow the reaction to be basically completely converted before reaching thermodynamic equilibrium, so as to obtain qualified products with low reverse-reverse ratio.

[0004] The MDA hydrogenation catalyst is mainly a noble metal-loaded catalyst, which is prepared by loading the active components rhodium and ruthenium onto carriers such as alumina, activated carbon, silica, molecular sieves, and spinel.

[0005] Patent CN117658824A discloses a method of producing H12MDA by hydrogenation with H6MDA and MDA as raw materials under the action of a supported catalyst, achieving a 96.78% H12MDA yield, and the catalyst can be recycled 60 times without loss of activity. However, the product obtained by this technology has a high content of impurities such as heavy components and other components, and the subsequent separation cost increases.

[0006] Patent CN1970528B discloses a ruthenium-based catalyst for hydrogenating aromatic amines to their corresponding alicyclic amines. The catalyst is prepared by applying ruthenium to a lithium spinel support or carrier by impregnation, coating, coprecipitation, etc. When hydrogenating MDA to H12MDA, adding LiOH to the ruthenium / lithium aluminate catalyst can reduce the secondary amine byproduct content from 42% to 8.8%. Although the formation of secondary amines is suppressed, the content is still high, resulting in a low product yield.

[0007] Patent CN102008969B discloses a hydrogen-type montmorillonite-loaded ruthenium catalyst, with an active component Ru loading of 5%-10%. Under a reaction pressure of 8MPa and a reaction temperature of 120°C, the MDA conversion rate can reach 100%, the H12MDA yield is 92.49%, and the anti-anti ratio is 19.45%. Although the conversion rate of this technology is 100%, the yield still needs to be improved.

[0008] Patent CN100534974C discloses a method for preparing H12MDA by hydrogenation reaction of MDA catalyzed by a supported nano-ruthenium catalyst. Under the conditions of temperature 100-180°C and pressure 4-10MPa, after 1-9 hours of reaction, the conversion rate of raw material MDA can be close to 100%, wherein the content of trans H12MDA is less than 25%. After 30 applications, the content of trans isomer is less than 27%. Although the content of trans isomer is already low, the trans content still needs to be further reduced. Summary of the invention

[0009] The object of the present invention is to provide a method for preparing H12MDA by catalytic hydrogenation of MDA, which can improve the yield of H12MDA product and significantly reduce the content of trans-trans isomers in the product.

[0010] Another object of the present invention is to provide a catalyst for catalyzing the hydrogenation of MDA to prepare H12MDA, which has a long life and excellent stability, can increase the yield of the H12MDA target product, reduce the content of trans-trans isomers in the product, and has a simple preparation process.

[0011] In order to achieve the above object, the technical solution adopted by the present invention is:

[0012] A supported catalyst is used for catalyzing the hydrogenation reaction of 4,4'-diamino-diphenylmethane (MDA) to prepare 4,4'-diaminodicyclohexylmethane (H12MDA). The supported catalyst comprises a silicon-aluminum amorphous carrier and an active component. The silicon-aluminum amorphous carrier has microporous, mesoporous and macroporous structures and is prepared by hydrothermal reaction of raw materials including an aluminum source and a silicon source in the presence of a template. The template is selected from one of 4,4-diaminodiphenylmethane (4,4-MDA) and 2,4-diaminodiphenylmethane (2,4-MDA) or a combination of the two.

[0013] In the present invention, the silicon-aluminum amorphous carrier refers to a carrier containing silicon and aluminum elements and in an amorphous state.

[0014] In the present invention, the pore size of micropores is less than 2 nm, the pore size of mesopores is 2-50 nm, and the pore size of macropores is greater than 50 nm. This definition is the same as that of the International Union of Pure and Applied Chemistry (IUPAC).

[0015] In the prior art, a lot of research has been conducted on catalysts for the production of H12MDA by hydrogenation reaction of MDA. However, the preparation methods of some catalysts are complicated, some catalysts bring other impurities to the product after use, which is not conducive to subsequent separation, some catalysts have a short service life, and are not stable enough. When some catalysts are used to catalyze the hydrogenation reaction, the content of trans-trans isomers in the obtained product is still not low enough. The inventors of this application have found through research that by improving the catalyst carrier, a template agent is used when synthesizing the catalyst carrier, which is a small molecule soft template agent with substantially the same molecular structure as the substrate, and its function is similar to molecular imprinting, so that the carrier forms a pore system that is more suitable for the reaction substrate; the obtained carrier is a molecular sieve precursor, showing the characteristics of short-range order and long-range disorder, in an amorphous state, and no molecular sieve crystal form is formed.

[0016] The present invention obtains a silicon-aluminum amorphous carrier of a micropore-mesopore-macroporous composite pore system by adding a reaction substrate MDA as a template. The carrier has abundant micropores, mesopores and macropores, and has a pore system that is more suitable for the reaction, which accelerates the mass transfer of the reaction substrate in the catalyst pores and the desorption and diffusion of the reaction products, increases the hydrogenation rate, and can inhibit other side reactions, thereby increasing the yield of the target product and reducing the content of the trans-trans isomer.

[0017] In some embodiments, in the silicon-alumina amorphous support, the volume ratio of micropores, mesopores and macropores is 1:

[0018] (50-150):(100-200).

[0019] Preferably, in the silicon-aluminum amorphous carrier, the volume ratio of micropores, mesopores and macropores is 1:(60-130):

[0020] (110-180).

[0021] In some embodiments, the aluminum source is selected from a combination of one or more of aluminum sulfate, sodium aluminate, and aluminum isopropoxide; and / or, the silicon source is selected from a combination of one or more of white carbon black, silica sol, silica gel, and tetraethyl orthosilicate.

[0022] In some embodiments, the silicon source is calculated as silicon dioxide, the aluminum source is calculated as aluminum oxide, and the molar ratio of the silicon source to the aluminum source is 10-1000:1; preferably 50-200:1.

[0023] In some embodiments, the silicon source is calculated as silicon dioxide, and the molar ratio of the template to the silicon source is 0.01-1.0:1; preferably 0.05-0.5:1.

[0024] In some embodiments, the raw material further comprises a second template, and the second template is selected from organic amines and / or quaternary ammonium salts. The second template is a structure-directing agent, which forms a structural unit of the amorphous carrier.

[0025] In some embodiments, the raw material further includes an inorganic base and water.

[0026] In some embodiments, the inorganic base is selected from a combination of one or more of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate.

[0027] In some embodiments, the organic amine is selected from 1,6-hexanediamine or 1,8-octanediamine; and / or the quaternary ammonium salt is selected from a combination of one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide and tetrabutylammonium bromide.

[0028] In some embodiments, when the raw material contains a sodium compound, the sodium compound is calculated as sodium oxide, the silicon source is calculated as silicon dioxide, and the molar ratio of the sodium compound to the silicon source is 0.01-0.4:1; preferably 0.05-0.2:1.

[0029] In some embodiments, when the raw material contains a potassium compound, the potassium compound is calculated as potassium oxide, the silicon source is calculated as silicon dioxide, and the molar ratio of the potassium compound to the silicon source is 0.01-0.4:1; preferably 0.05-0.2:1.

[0030] In some embodiments, the silicon source is calculated as silicon dioxide, and the molar ratio of the second template to the silicon source is 0.01-1.0:1, preferably 0.1-0.5:1.

[0031] In some embodiments, the silicon source is calculated as silicon dioxide, and the molar ratio of the water to the silicon source is 5-50:1, preferably 10-30:1.

[0032] In some embodiments, the active component is selected from one or a combination of ruthenium and rhodium.

[0033] In some embodiments, the mass of the active component accounts for 0.2%-20% of the mass of the amorphous silica-alumina support, preferably 0.5%-10%.

[0034] The present invention also provides a method for preparing the aforementioned supported catalyst, the preparation method comprising the following steps: subjecting raw materials including an aluminum source and a silicon source and a template to a hydrothermal reaction, and roasting the solid after solid-liquid separation to obtain the silicon-aluminum amorphous carrier; and loading an active component on the silicon-aluminum amorphous carrier to obtain the supported catalyst.

[0035] In some embodiments, the temperature of the hydrothermal reaction is 60-180°C, preferably 90-160°C.

[0036] In some embodiments, the hydrothermal reaction time is 5-50 h, preferably 10-30 h.

[0037] In some embodiments, the calcination temperature is 450-550°C.

[0038] In some embodiments, the calcination time is 3-10 hours.

[0039] In some embodiments, the active component is loaded on the silica-alumina amorphous support by an impregnation method.

[0040] In some embodiments, the impregnation method comprises the steps of impregnating the silicon-aluminum amorphous support with a metal salt solution of an active component, filtering, drying, and hydrogenating and reducing.

[0041] In some embodiments, the metal salt solution of the active component also includes a surfactant. Using a surfactant such as sodium dodecylbenzene sulfonate as a dispersant, the carrier is impregnated with the active component, and the prepared catalyst has a higher degree of dispersion and more active sites, and can react under relatively mild conditions, further improving the yield of the H12MDA product, and further reducing the content of the trans-trans isomer in the product, thereby extending the life of the catalyst.

[0042] Preferably, the surfactant is selected from one or more combinations of sodium dodecylbenzene sulfonate, dodecylammonium bromide, and dodecyltrimethylammonium bromide.

[0043] In some embodiments, the mass percentage of the surfactant in the metal salt solution of the active component is 0.01%-1%, preferably 0.1%-0.4%.

[0044] In some embodiments, the immersion time is 1-10 hours, preferably 3-6 hours.

[0045] In some embodiments, the temperature of the hydrogenation reduction is 300-600°C, preferably 400-500°C.

[0046] In some embodiments, the hydrogenation reduction time is 1-20 h, preferably 3-8 h.

[0047] The present invention also provides a method for preparing 4,4'-diaminodicyclohexylmethane, which comprises taking 4,4'-diamino-diphenylmethane and hydrogen as raw materials, carrying out a hydrogenation reaction in the presence of a solvent and a catalyst to obtain the 4,4'-diaminodicyclohexylmethane, wherein the catalyst is the aforementioned supported catalyst of the present invention.

[0048] In some embodiments, the mass ratio of the catalyst to 4,4'-diamino-diphenylmethane is 0.01-0.1:1, preferably 0.02-0.06:1.

[0049] In some embodiments, the solvent is selected from one or more combinations of methanol, ethanol, n-propanol, isopropanol, n-butanol, tetrahydrofuran, dioxane, n-hexane and methylcyclohexane; preferably tetrahydrofuran.

[0050] In some embodiments, the mass ratio of the solvent to 4,4'-diamino-diphenylmethane is 1-10; preferably 1-4.

[0051] In some embodiments, the temperature of the hydrogenation reaction is 80-180°C; preferably 100-130°C.

[0052] In some embodiments, the pressure of the hydrogenation reaction is 2-20 MPa, preferably 6-10 MPa.

[0053] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0054] The present invention uses a template (4,4-MDA and / or 2,4-MDA) as a template to carry out a hydrothermal reaction to synthesize a catalyst carrier, forming a silicon-aluminum amorphous carrier of a micropore-mesopore-macroporous composite pore system, which is short-range ordered and long-range disordered, and has abundant micropores, mesopores and stacked macropores. The present invention uses the above-mentioned reaction substrate MDA as a soft template, which can induce the formation of mesopores, and the mesopores have a structure similar to that of the substrate MDA, so that the synthesized carrier has a pore system that is more suitable for the reaction of the present invention, and can significantly improve the mass transfer performance of the catalyst. Preferably, when synthesizing the silicon-aluminum amorphous carrier, a second template is also used, and the second template (traditional organic template) induces the formation of micropores, and the micropores provide a higher specific surface area, which can improve the dispersibility of the loaded active metal, thereby improving the catalyst activity.

[0055] Due to the improvement of catalyst activity and mass transfer performance, the reaction time is shortened, and the reactants are completely converted before reaching thermodynamic equilibrium, which is conducive to obtaining the target product H12MDA with low trans-trans isomer content. In addition, since the carrier has a rich pore system, the blockage of the pores by the heap material is reduced, and the active components of the catalyst are more evenly dispersed on the silicon-aluminum amorphous carrier with a microporous-mesoporous-macroporous composite pore system, and are not easy to agglomerate in subsequent use, which greatly extends the catalyst life.

[0056] When the catalyst of the present invention is used for catalyzing the hydrogenation reaction of MDA to obtain H12MDA, the H12MDA yield is more than 98%, the trans-trans isomer content is less than 15%, and the catalytic activity is basically not reduced after being used for dozens of times. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is the N2 adsorption-desorption diagram of the microporous-mesoporous-macroporous composite pore system silicon-aluminum amorphous carrier obtained in Example 1;

[0058] Figure 2 This is the pore size distribution diagram of the microporous-mesoporous-macroporous composite pore system silicon-aluminum amorphous carrier obtained in Example 1. DETAILED DESCRIPTION

[0059] The technical solution of the present invention is described in detail below in conjunction with specific embodiments so that those skilled in the art can better understand and implement the technical solution of the present invention, but the present invention is not limited to the scope of the examples.

[0060] Example 1

[0061] This embodiment provides a supported catalyst, and uses the supported catalyst to catalyze the hydrogenation reaction of MDA to obtain H12MDA:

[0062] Under stirring conditions, 3.16 g of white carbon black (95.0 wt.% SiO2, 5.0 wt.% H2O), 0.21 g of sodium hydroxide (96.0 wt.% NaOH), 0.18 g of aluminum sulfate (99.5 wt.%), 12.97 g of tetrabutylammonium hydroxide aqueous solution (TBAOH, purity ≥ 40 wt.%), 1.05 g of deionized water and 1.04 g of 4,4-MDA (99.0 wt.%) were added to a reaction kettle. The molar composition of the raw material mixture is: SiO2 / Al2O3=100, Na2O / SiO2=0.05, TBA + / SiO2=0.4, and 4,4-MDA / SiO2=0.1, H2O / SiO2=10. After the raw materials are uniformly mixed, hydrothermal synthesis is carried out at 150℃ (40 rpm) for 15h. After that, the product is separated from the solid and liquid, and the solid product is filtered, dried and calcined (500℃, 5h) to obtain a microporous-mesoporous-macroporous composite pore system silicon-aluminum amorphous carrier. Its N2 adsorption-desorption diagram and pore size distribution diagram are shown as follows: Figure 1 and Figure 2 As shown, it can be seen that the carrier has abundant pores in the range of micropores, mesopores and macropores, and the volume ratio of micropores, mesopores and macropores is 1:120:165.

[0063] Dissolve 0.31g RuCl3 in 10ml distilled water and stir to obtain a precursor solution. Disperse sodium dodecylbenzene sulfonate into the precursor solution with a mass concentration of 0.2wt%, then add 3g of the silicon-aluminum amorphous carrier prepared above, stir for 6h while ultrasonicating, filter, wash with distilled water, and dry. Place the obtained product in a tubular furnace and reduce it with hydrogen at 500℃ for 6h to obtain a highly dispersed supported Ru catalyst with a ruthenium loading of 5%.

[0064] In the reactor, add 10g of tetrahydrofuran, 5g of raw material MDA and 0.2g of the supported Ru catalyst prepared above. Close the reactor, replace with nitrogen and hydrogen respectively, control the reaction temperature to 110°C and the reaction pressure to 8MPa, and react at a constant temperature. When the hydrogen consumption rate in the reactor is basically zero, the reaction is completed, the pressure is vented, the reaction materials are discharged, the catalyst is filtered out, and the product composition is analyzed by gas chromatography. The results are shown in Table 1 below.

[0065] Example 2

[0066] This embodiment provides a supported catalyst, and uses the supported catalyst to catalyze the hydrogenation reaction of MDA to obtain H12MDA:

[0067] Under stirring conditions, 9.81 g of silica sol (30.57 wt.% SiO2, 0.327 wt.% Na2O, 0.033 wt.% Al2O3, 69.07 wt.% H2O), 0.335 g of sodium aluminate (49.0 wt.% Al2O3, 38.0 wt.% Na2O, 13.0 wt.% H2O), 1.32 g of potassium hydroxide (KOH purity ≥ 96 wt.%), 1.63 g of tetrabutylammonium bromide (TBABr, purity ≥ 99 wt.%), 1.00 g of 2,4-MDA (99.0 wt.%) and 11.20 g of deionized water were added to a reaction kettle. The molar composition of the raw material mixture is: SiO2 / Al2O3 = 30, K2O / SiO2 = 0.22, TBABr = 0.5 + / SiO2=0.1,2,4-MDA / SiO2=0.1,H2O / SiO2=20. After the raw materials are uniformly mixed, hydrothermal synthesis is carried out at 160℃ (40 rpm) for 10h. After that, the product is separated from the solid and liquid, and the solid product is filtered, dried and calcined (450℃, 10h) to obtain a microporous-mesoporous-macroporous composite pore system of silicon-aluminum amorphous carrier. The volume ratio of micropores, mesopores and macropores is 1:110:160.

[0068] Dissolve 0.12g RhCl3 in 10ml distilled water and stir well to obtain a precursor solution. Disperse dodecyl ammonium bromide into the precursor solution with a mass concentration of 0.4wt%, then add 3g of the silicon-aluminum amorphous carrier prepared above, stir well for 8h while ultrasonicating, filter, wash with distilled water, and dry. Place the obtained product in a tubular furnace and reduce it with hydrogen at 500℃ for 4h to obtain a highly dispersed Rh-loaded catalyst with a rhodium loading of 2%.

[0069] In the reactor, 5g of methanol, 5g of raw material MDA and 0.3g of the supported catalyst prepared above were added, the reactor was closed, replaced with nitrogen and hydrogen respectively, the reaction temperature was controlled at 120°C and the reaction pressure was 6MPa, and the reaction was carried out at a constant temperature. When the hydrogen consumption rate in the reactor was basically zero, the reaction was terminated, the pressure was vented, the reaction materials were discharged, the catalyst was filtered out, and the analysis was performed by gas chromatography. The results are shown in Table 1 below.

[0070] Example 3

[0071] This embodiment provides a supported catalyst, and uses the supported catalyst to catalyze the hydrogenation reaction of MDA to obtain H12MDA:

[0072] Under stirring conditions, 12.24 g of silica gel (98.0 wt. % SiO2, 2.0 wt. % H2O), 0.41 g of aluminum isopropoxide (99 wt. %), 0.83 g of sodium hydroxide (96.0 wt. % NaOH), 4.10 g of tetrapropylammonium hydroxide (TPAOH, purity ≥ 99 wt. %), 0.40 g of 2,4-MDA (99.0 wt. %) and 17.76 g of deionized water were added to a reaction kettle. The molar composition of the raw material mixture was: SiO2 / Al2O3 = 200, Na2O / SiO2 = 0.05, TPAOH = 0.1%; + / SiO2=0.1,2,4-MDA / SiO2=0.01,H2O / SiO2=5. After the raw materials are uniformly mixed, hydrothermal synthesis is carried out at 160℃ (40 rpm) for 20h. After that, the product is separated from the solid and liquid, and the solid product is filtered, dried and calcined (550℃, 3h) to obtain a microporous-mesoporous-macroporous composite pore system of silicon-aluminum amorphous carrier. The volume ratio of micropores, mesopores and macropores is 1:60:150.

[0073] Dissolve 0.186g of RuCl3 in 10ml of distilled water and stir well to obtain a precursor solution. Disperse dodecyltrimethylammonium bromide into the precursor solution with a mass concentration of 0.2wt%, then add 3g of the silicon-aluminum amorphous carrier prepared above, stir well for 8h while ultrasonicating, filter, wash with distilled water, and dry. Place the obtained product in a tubular furnace and reduce it with hydrogen at 450°C for 8h to obtain a highly dispersed Ru catalyst with a ruthenium loading of 3%.

[0074] In the reactor, 20 g of dioxane, 5 g of raw material MDA and 0.1 g of the supported catalyst prepared above were added, the reactor was closed, replaced with nitrogen and hydrogen respectively, the reaction temperature was controlled at 120°C and the reaction pressure was 6 MPa, and the reaction was carried out at a constant temperature. When the hydrogen consumption rate in the reactor was substantially zero, the reaction was terminated, the pressure was vented, the reaction materials were discharged, the catalyst was filtered out, and the analysis was performed by gas chromatography. The results are shown in Table 1 below.

[0075] Example 4

[0076] This embodiment provides a supported catalyst, and uses the supported catalyst to catalyze the hydrogenation reaction of MDA to obtain H12MDA:

[0077] Under stirring conditions, 6.32 g of white carbon black (95.0 wt.% SiO 2，5.0wt.%H2O), 0.41g sodium hydroxide (96.0wt.%NaOH), 0.17g aluminum sulfate (99.5wt.%), 6.49g tetrabutylammonium hydroxide aqueous solution (TBAOH, purity ≥40wt.%), 31.79g deionized water and 2.01g 4,4-MDA (99.0wt.%) were added to the reaction kettle. The molar composition of the raw material mixture is: SiO2 / Al2O3=200, Na2O / SiO2=0.05, TBA + / SiO2=0.1,4,4-MDA / SiO2=0.1,H2O / SiO2=20. After the raw materials are uniformly mixed, hydrothermal synthesis is carried out at 160℃ (40 rpm) for 10h. After that, the product is separated from the solid and liquid, and the solid product is filtered, dried and calcined (480℃, 8h) to obtain a microporous-mesoporous-macroporous composite pore system of silicon-aluminum amorphous carrier. The volume ratio of micropores, mesopores and macropores is 1:130:180.

[0078] Dissolve 0.07g RuCl3 in 10ml distilled water and stir well to obtain a precursor solution. Disperse sodium dodecylbenzene sulfonate into the precursor solution with a mass concentration of 0.2wt%, then add 3g of the silicon-aluminum amorphous carrier prepared above, stir well for 3h while ultrasonicating, filter, wash with distilled water, and dry. Place the obtained product in a tubular furnace and reduce it with hydrogen at 500℃ for 6h to obtain a highly dispersed Ru catalyst with a ruthenium loading of 1%.

[0079] In the reactor, 20 g of tetrahydrofuran, 5 g of raw material MDA and 0.5 g of the supported catalyst prepared above were added, the reactor was closed, replaced with nitrogen and hydrogen respectively, the reaction temperature was controlled at 110°C and the reaction pressure was 8 MPa, and the reaction was carried out at a constant temperature. When the hydrogen consumption rate in the reactor was substantially zero, the reaction was terminated, the pressure was vented, the reaction materials were discharged, the catalyst was filtered out, and the analysis was performed by gas chromatography. The results are shown in Table 1 below.

[0080] Example 5

[0081] This embodiment provides a supported catalyst, and uses the supported catalyst to catalyze the hydrogenation reaction of MDA to obtain H12MDA:

[0082] Under stirring conditions, 19.63 g of silica sol (30.57 wt.% SiO2, 0.327 wt.% Na2O, 0.033 wt.% Al2O3, 69.07 wt.% H2O), 0.335 g of sodium aluminate (49.0 wt.% Al2O3, 38.0 wt.% Na2O, 13.0 wt.% H2O), 3.63 g of potassium hydroxide (KOH purity ≥ 96 wt.%), 3.26 g of tetrabutylammonium bromide (TBABr, purity ≥ 99 wt.%), 1.00 g of 4,4-MDA (99.0 wt.%) and 4.46 g of deionized water were added to a reaction kettle. The molar composition of the raw material mixture is: SiO2 / Al2O3 = 100, K2O / SiO2 = 0.22, TBABr = 0.5 + / SiO2=0.1,4,4-MDA / SiO2=0.05,H2O / SiO2=10. After the raw materials are uniformly mixed, hydrothermal synthesis is carried out at 150℃ (40 rpm) for 15h. After that, the product is separated from the solid and liquid, and the solid product is filtered, dried and calcined (520℃, 4h) to obtain a microporous-mesoporous-macroporous composite pore system of silicon-aluminum amorphous carrier. The volume ratio of micropores, mesopores and macropores is 1:100:110.

[0083] Dissolve 0.31g RuCl3 in 10ml distilled water and stir well to obtain a precursor solution. Disperse dodecyl ammonium bromide into the precursor solution with a mass concentration of 0.4wt%, then add 3g of the silicon-aluminum amorphous carrier prepared above, stir well for 8h while ultrasonicating, filter, wash with distilled water, and dry. Place the obtained product in a tubular furnace and reduce it with hydrogen at 500℃ for 4h to obtain a highly dispersed Ru catalyst with a ruthenium loading of 5%.

[0084] In the reactor, 10 g of dioxane, 5 g of raw material MDA and 0.2 g of the supported catalyst prepared above were added, the reactor was closed, and the gas was replaced with nitrogen and hydrogen respectively, and the reaction temperature was controlled at 100° C. and the reaction pressure was 10 MPa, and the reaction was carried out at a constant temperature. When the hydrogen consumption rate in the reactor was substantially zero, the reaction was terminated, the pressure was vented, the reaction materials were discharged, the catalyst was filtered out, and the analysis was performed by gas chromatography. The results are shown in Table 1 below.

[0085] Example 6

[0086] This embodiment provides a supported catalyst, and uses the supported catalyst to catalyze the hydrogenation reaction of MDA to obtain H12MDA:

[0087] Under stirring conditions, 3.06 g of silica gel (98.0 wt. % SiO2, 2.0 wt. % H2O), 0.41 g of aluminum isopropoxide (99 wt. %), 0.21 g of sodium hydroxide (96.0 wt. % NaOH), 2.58 g of tetrapropylammonium hydroxide (TPAOH, purity ≥ 40 wt. %), 1.01 g of 2,4-MDA (99.0 wt. %) and 16.38 g of deionized water were added to a reaction kettle. The molar composition of the raw material mixture was: SiO2 / Al2O3=50, Na2O / SiO2=0.05, TPAOH=0. + / SiO2=0.1,2,4-MDA / SiO2=0.1,H2O / SiO2=20. After the raw materials are uniformly mixed, hydrothermal synthesis is carried out at 120℃ (40 rpm) for 20h. After that, the product is separated from the solid and liquid, and the solid product is filtered, dried and calcined (500℃, 6h) to obtain a microporous-mesoporous-macroporous composite pore system of silicon-aluminum amorphous carrier. The volume ratio of micropores, mesopores and macropores is 1:100:120.

[0088] Dissolve 0.06g RhCl3 in 10ml distilled water and stir well to obtain a precursor solution. Disperse sodium dodecylbenzene sulfonate into the precursor solution with a mass concentration of 0.1wt%, then add 3g of the silicon-aluminum amorphous carrier prepared above, stir well for 6h while ultrasonicating, filter, wash with distilled water, and dry. Place the obtained product in a tubular furnace and reduce it with hydrogen at 400℃ for 8h to obtain a highly dispersed Rh-loaded catalyst with a rhodium loading of 1%.

[0089] In the reactor, 5g of methanol, 5g of raw material MDA and 0.2g of the supported catalyst prepared above were added, the reactor was closed, replaced with nitrogen and hydrogen respectively, the reaction temperature was controlled at 130°C and the reaction pressure was 6MPa, and the reaction was carried out at a constant temperature. When the hydrogen consumption rate in the reactor was basically zero, the reaction was terminated, the pressure was vented, the reaction materials were discharged, the catalyst was filtered out, and the analysis was performed by gas chromatography. The results are shown in Table 1 below.

[0090] Example 7

[0091] This embodiment provides a supported catalyst, and uses the supported catalyst to catalyze the hydrogenation reaction of MDA to obtain H12MDA:

[0092] Under stirring conditions, 3.16 g of white carbon black (95.0 wt.% SiO 2，5.0wt.%H2O), 0.21g sodium hydroxide (96.0wt.%NaOH), 0.17g sodium aluminate (49.0wt.%Al2O3, 38.0wt.%Na2O, 13.0wt.%H2O), 10.30g tetrapropylammonium hydroxide (TPAOH, purity ≥40wt.%), 3.11g deionized water and 0.51g 2,4-MDA (99.0wt.%) were added to the reaction kettle. The molar composition of the raw material mixture is: SiO2 / Al2O3=100,Na2O / SiO2=0.05,TPA + / SiO2=0.4,2,4-MDA / SiO2=0.05,H2O / SiO2=10. After the raw materials are uniformly mixed, hydrothermal synthesis is carried out at 150℃ (40 rpm) for 15h. After that, the product is separated from the solid and liquid, and the solid product is filtered, dried and calcined (480℃, 6h) to obtain a microporous-mesoporous-macroporous composite pore system of silicon-aluminum amorphous carrier. The volume ratio of micropores, mesopores and macropores is 1:90:180.

[0093] Dissolve 0.12g RuCl3 in 10ml distilled water and stir well to obtain a precursor solution. Disperse sodium dodecylbenzene sulfonate into the precursor solution with a mass concentration of 0.4wt%, then add 3g of the silicon-aluminum amorphous carrier prepared above, stir well for 8h while ultrasonicating, filter, wash with distilled water, and dry. Place the obtained product in a tube furnace and reduce it with hydrogen at 450℃ for 6h to obtain a highly dispersed Ru catalyst with a ruthenium loading of 2%.

[0094] In the reactor, 20 g of tetrahydrofuran, 5 g of raw material MDA and 0.2 g of the supported catalyst prepared above were added, the reactor was closed, replaced with nitrogen and hydrogen respectively, the reaction temperature was controlled at 120°C and the reaction pressure was 6 MPa, and the reaction was carried out at a constant temperature. When the hydrogen consumption rate in the reactor was substantially zero, the reaction was terminated, the pressure was vented, the reaction materials were discharged, the catalyst was filtered out, and the analysis was performed by gas chromatography. The results are shown in Table 1 below.

[0095] Comparative Example 1

[0096] This comparative example provides a supported catalyst, and uses it to catalyze the hydrogenation reaction of MDA to obtain H12MDA. The specific steps are basically the same as those in Example 1, except that 4,4-MDA is not added as one of the template agents when synthesizing the catalyst carrier. The reaction system is also analyzed by gas chromatography, and the results are shown in Table 1 below.

[0097] Comparative Example 2

[0098] This comparative example provides a supported catalyst, and uses it to catalyze the hydrogenation reaction of MDA to obtain H12MDA. The specific steps are basically the same as those in Example 2, except that 2,4-MDA is not added as one of the template agents when synthesizing the catalyst carrier. The reaction system is also analyzed by gas chromatography, and the results are shown in Table 1 below.

[0099] Table 1 Results of various embodiments and comparative examples

[0100]

[0101] It can be seen that in Example 1, the MDA conversion rate is close to 100%, the H12MDA yield is more than 98%, and the trans-trans isomer content is less than 15%. In Comparative Examples 1 or 2, 4,4-MDA or 2,4-MDA is not added as a template, and the H12MDA yield is reduced, and the trans-trans ratio content is also greatly increased. It can be seen that the present invention adds the reaction substrate MDA as one of the templates to obtain a silicon-aluminum amorphous carrier with rich micropores, mesopores and macropore structures. The carrier has a pore system that is more suitable for the hydrogenation reaction of the present invention, accelerates the mass transfer of the reaction substrate in the catalyst pores, and the desorption and diffusion of the reaction products, improves the hydrogenation rate, and can inhibit other side reactions, improve the product yield, and achieve the control of the low trans-trans ratio content of the target product.

[0102] Example 8 (Catalyst Application)

[0103] According to Example 1, the prepared catalyst was tested for MDA hydrogenation reaction. The reaction results are shown in Table 2.

[0104] Table 2 Example 1 Catalyst Application Reaction Results

[0105] Number of applications MDA conversion % H12MDA yield / % Anti-H12MDA / % 1 99.8 99.2 11.8 10 99.7 98.8 11.5 20 99.8 99.1 10.9 30 99.5 98.7 11.3 40 99.8 99.1 11.2 50 99.8 99.2 11.5 60 99.6 98.8 10.2 70 99.5 99.2 10.8 80 99.7 99.0 11.7

[0106] As shown in Table 2, the catalyst prepared in Example 1 has good stability. After 80 cycles, the MDA conversion rate and yield did not decrease significantly, and the H12MDA trans-trans isomer content was still below 12.0%. It can be seen that the catalyst has excellent stability and a long service life.

[0107] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A supported catalyst for catalyzing the hydrogenation reaction of 4,4'-diamino-diphenylmethane to prepare 4,4'-diaminodicyclohexylmethane, characterized in that: The supported catalyst comprises a silicon-aluminum amorphous carrier and an active component. The silicon-aluminum amorphous carrier has microporous, mesoporous and macroporous structures and is prepared by hydrothermal reaction of raw materials including an aluminum source and a silicon source in the presence of a template. The template is selected from one of 4,4-diaminodiphenylmethane and 2,4-diaminodiphenylmethane or a combination of the two.

2. The supported catalyst according to claim 1, characterized in that: In the silicon-aluminum amorphous carrier, the volume ratio of micropores, mesopores and macropores is 1:50-150:100-200.

3. The supported catalyst according to claim 1, characterized in that: The aluminum source is selected from a combination of one or more of aluminum sulfate, sodium aluminate and aluminum isopropoxide; and / or, the silicon source is selected from a combination of one or more of white carbon black, silica sol, silica gel and tetraethyl orthosilicate; and / or, the silicon source is calculated as silicon dioxide, the aluminum source is converted into aluminum oxide, and the molar ratio of the silicon source to the aluminum source is 10-1000:1; and / or, the silicon source is calculated as silicon dioxide, and the molar ratio of the template to the silicon source is 0.01-1.0:

1.

4. The supported catalyst according to claim 1, characterized in that: The raw material further includes a second template, and the second template is selected from organic amines and / or quaternary ammonium salts; preferably, the raw material further includes an inorganic base and water.

5. The supported catalyst according to claim 4, characterized in that: The inorganic base is selected from a combination of one or more of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate; and / or the organic amine is selected from 1,6-hexanediamine or 1,8-octanediamine; and / or the quaternary ammonium salt is selected from a combination of one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide and tetrabutylammonium bromide.

6. The supported catalyst according to claim 5, characterized in that: When the raw material contains a sodium compound, the sodium compound is calculated as sodium oxide, the silicon source is calculated as silicon dioxide, and the molar ratio of the sodium compound to the silicon source is 0.01-0.4:1; and / or, when the raw material contains a potassium compound, the potassium compound is calculated as potassium oxide, the silicon source is calculated as silicon dioxide, and the molar ratio of the potassium compound to the silicon source is 0.01-0.4:1; and / or, the silicon source is calculated as silicon dioxide, and the molar ratio of the second template to the silicon source is 0.01-1.0:1; and / or, the silicon source is calculated as silicon dioxide, and the molar ratio of water to the silicon source is 5-50:

1.

7. The supported catalyst according to claim 1, characterized in that: The active component is selected from one or a combination of ruthenium and rhodium; and / or the mass of the active component accounts for 0.2%-20% of the mass of the amorphous silicon-aluminum carrier.

8. A method for preparing a supported catalyst according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: subjecting raw materials including an aluminum source and a silicon source and a template to a hydrothermal reaction, and roasting the solid after solid-liquid separation to obtain the silicon-aluminum amorphous carrier; and loading active components on the silicon-aluminum amorphous carrier to obtain the loaded catalyst.

9. The method for preparing a supported catalyst according to claim 8, wherein: The temperature of the hydrothermal reaction is 60-180° C.; and / or, the time of the hydrothermal reaction is 5-50 h; and / or, the temperature of the calcination is 450-550° C.; and / or, the time of the calcination is 3-10 h.

10. The method for preparing a supported catalyst according to claim 8, characterized in that: The active components are loaded on the silicon-aluminum amorphous carrier by an impregnation method; preferably, the impregnation method comprises the steps of impregnating the silicon-aluminum amorphous carrier with a metal salt solution of the active components, filtering, drying, and hydrogenation reduction.

11. The method for preparing a supported catalyst according to claim 10, characterized in that: The metal salt solution of the active component also includes a surfactant; preferably, the surfactant is selected from sodium dodecylbenzene sulfonate, dodecyl ammonium bromide A combination of one or more of dodecyltrimethylammonium bromide; and / or, the mass percentage of the surfactant in the metal salt solution of the active component is 0.01%-1%; and / or, the impregnation time is 1-10h; and / or, the hydrogenation reduction temperature is 300-600°C; and / or, the hydrogenation reduction time is 1-20h.

12. A method for preparing 4,4'-diaminodicyclohexylmethane, which comprises taking 4,4'-diamino-diphenylmethane and hydrogen as raw materials, and carrying out a hydrogenation reaction in the presence of a solvent and a catalyst to obtain the 4,4'-diaminodicyclohexylmethane, characterized in that: The catalyst is a supported catalyst according to any one of claims 1 to 7.

13. The method for preparing 4,4'-diaminodicyclohexylmethane according to claim 12, characterized in that: The mass ratio of the catalyst to 4,4'-diamino-diphenylmethane is 0.01-0.1:1; and / or the solvent is selected from a combination of one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, tetrahydrofuran, dioxane, n-hexane and methylcyclohexane; and / or the mass ratio of the solvent to 4,4'-diamino-diphenylmethane is 1-10; and / or the temperature of the hydrogenation reaction is 80-180°C; and / or the pressure of the hydrogenation reaction is 2-20MPa.

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