Catalyst for preparing diphenylmethane and preparation thereof, diphenylmethane and synthesis method thereof

Abstract

The present invention provides a catalyst for preparing diphenylmethane and its preparation, diphenylmethane and its synthesis method, wherein the catalyst comprises a metal organic framework material MIL-101 (X 1 , X 2 ), where X 1 For iron and / or aluminum, X 2 The catalyst comprises a metal organic framework material MIL-101 (X 1 , X 2 ), the catalyst not only has a stable structure, but also will not react with by-products during the preparation of diphenylmethane, and has a low cost, so it has strong practicality, good recyclability, and high economy in the preparation of diphenylmethane; in addition, when the catalyst is used to prepare diphenylmethane, it shows a high conversion rate and selectivity, shortens the preparation time, increases production capacity, reduces the difficulty of post-processing, and improves safety.

Description

Technical Field

[0001] The invention belongs to the technical field of diphenylmethane preparation, and relates to a catalyst for preparing diphenylmethane, in particular to a catalyst for preparing diphenylmethane and its preparation, diphenylmethane and a synthesis method thereof. Background Art

[0002] Diphenylmethane (DPM) is a colorless needle-shaped crystal at room temperature. It is often used in the perfume industry to make fragrance preservatives, soaps, and color fixatives because of its strong aroma of geranium oil and sweet orange. It is also an important dye and drug intermediate, and is used in the pharmaceutical industry to produce diphenhydramine hydrochloride. It is also widely used in fine chemicals and insulators, as a synergist for pesticides and insecticides, an additive to change the thermal stability of polyester and jet fuel, and an insulating material for the manufacture of printed circuit boards. In recent years, due to the increase in demand for diphenylmethane-related manufacturing products, the market demand for diphenylmethane has expanded, and its industrialization has good market prospects and significant economic benefits. It is precisely because of the above-mentioned important and wide applications of DPM that its synthesis method has attracted much attention.

[0003] At present, the industry mainly uses benzene and benzyl chloride as raw materials to synthesize diphenylmethane through Friedel Crafts reaction. The traditional catalyst for synthesizing diphenylmethane is mainly liquid acid, such as sulfuric acid, hydrofluoric acid, aluminum chloride and zinc chloride, which are easy to produce polyalkylated products. Generally, a large excess of highly toxic benzene is added to inhibit the polyalkylated products. However, even so, the selectivity of the product is still not very high. Generally, the yield of the product is only between 60% and 70%. In addition, there are problems such as easy corrosion of equipment, environmental pollution, inability to regenerate the catalyst and complex product post-processing process during use.

[0004] In recent years, researchers have developed the following catalysts for diphenylmethane synthesis: (1) metal halides and their immobilized catalysts. The carriers of such catalysts are generally clay, attapulgite, activated carbon, and alumina, which have advantages such as pore structure and high specific surface area. Metal halide immobilized catalysts have the advantages of both heterogeneous catalysts and homogeneous catalysts, with high activity, good stability, low corrosiveness, and easy recycling. However, this type of catalyst itself will hydrolyze to produce HCl and form an acidic solution, which limits the practicality of this type of catalyst in the synthesis of diphenylmethane; (2) Zeolite molecular sieve catalysts. Due to their specific pore size and structure, zeolite molecular sieves have properties such as acidity and ion exchange. However, the high cost of synthesizing the catalyst material limits its industrial production; (3) Oxidation catalysts. This type of catalyst loads metal oxides into zeolites or mesoporous materials, and introduces metal ions into the carrier skeleton through hydrothermal or ion exchange to prepare oxidation catalysts. However, the metal oxides will react with the generated HCl to generate a small amount of water, which reduces the reaction activity and affects the recovery of the catalyst.

[0005] CN101816944A discloses a method for preparing a solid acid catalyst for preparing diphenylmethane, and the steps are: selecting attapulgite clay with a content of more than 70% as a carrier, acidifying the attapulgite clay with a concentration of 3-5% sulfuric acid, and loading ZnCl2 or AlCl3 onto the attapulgite clay by an impregnation method; the process of using the solid acid catalyst prepared by the present invention to prepare diphenylmethane is: first adding benzene and a catalyst into a reaction container, stirring and slowly heating to 50°C, stirring for 30 minutes, slowly adding benzyl chloride, raising the reaction temperature to 70°C, reacting for 6 hours, stopping heating, removing a drying tube containing CaCl2, and then reacting for another 0.5 hour. After cooling to room temperature, the reaction liquid is filtered out by suction, and the catalyst is recovered for reuse.

[0006] CN102329191A discloses a method for preparing diphenylmethane or its derivatives, and the steps are as follows: first, prepare a solid aluminum chloride catalyst with chitosan as a carrier, then use the solid aluminum chloride as a catalyst, benzene or a benzene derivative and benzyl chloride as raw materials, react at 75-100°C, and after the reaction is completed, filter the reaction solution and distill under reduced pressure to obtain diphenylmethane or its derivatives. In the preparation process of the present invention, the prepared solid aluminum chloride is a high-load, high-catalytic activity, reusable green, environmentally friendly solid catalyst, which can be reused many times after the catalyst is recovered, and the catalytic activity remains unchanged. The reaction of preparing diphenylmethane and its derivatives by using the solid aluminum chloride generates less wastewater, and the catalyst and the product are easy to separate.

[0007] The catalysts disclosed in the prior art for preparing diphenylmethane all have certain defects, such as the instability of the catalyst itself, the side reaction of the catalyst with the by-product, and the high preparation cost of the catalyst, which leads to the problems of low practicality, recyclability and economy of the catalyst. Therefore, it is very important to develop and design a new catalyst for preparing diphenylmethane and its preparation, diphenylmethane and its synthesis method. Summary of the invention

[0008] In view of the deficiencies in the prior art, the object of the present invention is to provide a catalyst for preparing diphenylmethane and its preparation, diphenylmethane and its synthesis method. The present application provides a novel catalyst for preparing diphenylmethane, the catalyst comprising a metal organic framework material MIL-101 (X1, X2), the catalyst not only has a stable structure itself, but also does not react with by-products in the process of preparing diphenylmethane, and has a low cost, so it has strong practicality, good recyclability, and high economy in the preparation of diphenylmethane; in addition, when the catalyst is used to prepare diphenylmethane, it shows a high conversion rate and selectivity, shortens the preparation time, increases the production capacity, reduces the difficulty of post-processing, and improves safety.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a catalyst for preparing diphenylmethane, wherein the catalyst comprises a metal organic framework material MIL-101 (X1, X2), wherein X1 is iron and / or aluminum, and X2 is any one of zinc, manganese or cobalt or a combination of at least two thereof.

[0011] In the present invention, X2 is any one of zinc, manganese or cobalt or a combination of at least two thereof. Typical but non-limiting combinations include a combination of zinc and manganese, a combination of manganese and cobalt, or a combination of zinc, manganese and cobalt.

[0012] Metal-Organic Frameworks (MOFs) are materials with two-dimensional or three-dimensional network structures formed by metal ions or clusters as nodes and organic ligands as bridges. Due to their high crystallinity, adjustable porosity, high specific surface area, large pore size and low density, they are used as functional materials in a variety of fields, such as gas storage, purification, sensing, drug delivery, biomedicine, photoluminescence and catalysis, and are particularly widely used in the field of heterogeneous catalysis. Even for MOFs with relatively perfect crystal structures, there will be more than one coordination position around the metal element that does not participate in the lattice construction. These positions are usually occupied by water molecules from the atmosphere or any ligands that may appear in the synthesis process. The coordination exchangeable positions that are not occupied by ligands can be eliminated after appropriate heating under vacuum, thereby generating Lewis acid sites and coordination unsaturated sites (CUS) around the metal ions. In addition, if there are defects in the structure, CUS may also be generated around the metal center. Therefore, MOFs can be used as acidic catalysts in reactions catalyzed by Lewis acid sites.

[0013] Using a direct synthesis method, by selecting different metal ions, such as Fe 3+ 、Al 3+ 、Zn 2+ , Lewis acid sites required for Friedel-Crafts alkylation can be obtained. Active species can be introduced into the pores of the material by the impregnation method. Its high specific surface area and ordered pore structure can be used as a carrier to load nanoparticle catalysts. The pores of MOFs have a confinement effect that can fix nanoparticles and inhibit their agglomeration to a certain extent, so that nanoparticles are evenly dispersed on the surface or in the pores of MOFs. In addition, because MOFs have high porosity, they can effectively reduce mass transfer problems during the reaction process and increase the interaction with the substrate, thereby greatly improving the catalytic reaction rate.

[0014] In this application, the MIL-101 material in the MOFs material is considered to be used as a catalyst for preparing diphenylmethane. Furthermore, since MIL-101 (Cr) loaded with ferric chloride as a catalyst for Friedel-Crafts alkylation shows good catalytic activity and selectivity, the Cr in the carrier is highly toxic and difficult to industrialize; MIL-101 (Fe) as a catalyst for Friedel-Crafts alkylation shows good catalytic activity, but due to the unstable skeleton structure of MIL-101 (Fe) itself, it is easily affected by water vapor in the air and the reaction system, resulting in the skeleton being destroyed, making it difficult to reuse the MIL-101 (Fe) catalyst.

[0015] Therefore, the present application provides a novel catalyst for preparing diphenylmethane, wherein the catalyst comprises a metal organic framework material MIL-101 (X1, X2). The catalyst not only has a stable structure itself, but also does not react with by-products during the preparation of diphenylmethane, and has a low cost. Therefore, the catalyst has strong practicality, good recyclability, and high economy in the preparation of diphenylmethane. In addition, when the catalyst is used to prepare diphenylmethane, a high conversion rate and selectivity are exhibited, and the preparation time is shortened, the production capacity is increased, the difficulty of post-processing is reduced, and the safety is improved.

[0016] Preferably, the molar ratio of X1 to X2 in the metal organic framework material MIL-101 (X1, X2) is 1:(0.1-0.3), for example, it can be 1:0.1, 1:0.12, 1:0.14, 1:0.16, 1:0.18, 1:0.2, 1:0.22, 1:0.24, 1:0.26, 1:0.28 or 1:0.3, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] Preferably, X1 is iron and X2 is zinc.

[0018] Preferably, the specific surface area of ​​the catalyst is 2700-2950m 2 / g, for example, it can be 2700m 2 / g, 2720m 2 / g, 2750m 2 / g, 2770m 2 / g, 2790m 2 / g、2800m 2 / g, 2810m 2 / g, 2830m 2 / g, 2850m 2 / g, 2870m 2 / g, 2890m 2 / g, 2910m 2 / g, 2930m 2 / g or 2950m 2 / g, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0019] Preferably, the micropore volume of the catalyst is 1.02 to 1.09 cm 3 / g, for example, 1.02 cm 3 / g, 1.03cm 3 / g, 1.04cm 3 / g, 1.05cm 3 / g, 1.06cm3 / g, 1.07cm 3 / g, 1.08cm 3 / g or 1.09cm 3 / g, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0020] In a second aspect, the present invention provides a method for preparing the catalyst according to the first aspect, the preparation method comprising:

[0021] The catalyst is obtained by heat-treating a mixed solution containing a first metal salt, a second metal salt, terephthalic acid and N,N-dimethylformamide.

[0022] The preparation method of the catalyst provided in the present invention is simple, the preparation cost is low, and the safety of the preparation process is high.

[0023] The method for preparing the mixed solution in the present invention comprises:

[0024] The mixed solution is obtained by ultrasonically mixing the first metal salt, the second metal salt, terephthalic acid and N,N-dimethylformamide.

[0025] It may also include:

[0026] The mixed solution is obtained by ultrasonically mixing the hydrate of the first metal salt, the hydrate of the second metal salt, terephthalic acid and N,N-dimethylformamide.

[0027] It may also include:

[0028] The mixed solution is obtained by ultrasonically mixing the first metal salt, the hydrate of the second metal salt, terephthalic acid and N,N-dimethylformamide.

[0029] It may also include:

[0030] The mixed solution is obtained by ultrasonically mixing the hydrate of the first metal salt, the second metal salt, terephthalic acid and N,N-dimethylformamide.

[0031] Preferably, the first metal salt comprises an iron salt and / or an aluminum salt.

[0032] Preferably, the first metal salt comprises any one or a combination of at least two of chloride, sulfate and / or nitrate, typical but non-limiting combinations include a combination of chloride and sulfate, a combination of sulfate and nitrate, or a combination of chloride, sulfate and nitrate.

[0033] Preferably, the second metal salt comprises any one of zinc salt, manganese salt or cobalt salt or a combination of at least two thereof, and typical but non-limiting combinations include a combination of zinc salt and manganese salt, a combination of manganese salt and cobalt salt, or a combination of zinc salt, manganese salt and cobalt salt.

[0034] Preferably, the second metal salt comprises any one or a combination of at least two of chloride, sulfate and / or nitrate, typical but non-limiting combinations include a combination of chloride and sulfate, a combination of sulfate and nitrate, or a combination of chloride, sulfate and nitrate.

[0035] Preferably, the heat treatment is carried out at a temperature of 100 to 170° C. and for a time of 5 to 24 hours.

[0036] The temperature of the heat treatment in the present invention is 100-170°C, for example, it can be 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C or 170°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] The heat treatment time in the present invention is 5 to 24 hours, for example, it can be 5 hours, 7 hours, 9 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours or 24 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] Preferably, the preparation method further comprises post-treatment after the heat treatment, and the post-treatment comprises: solid-liquid separation to obtain a brown solid, and then sequentially washing and drying the obtained brown solid to obtain the catalyst.

[0039] Preferably, the drying is vacuum drying, and the temperature of the vacuum drying is 90-180°C, for example, it can be 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C or 180°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] In a third aspect, the present invention provides a method for synthesizing diphenylmethane using the catalyst described in the first aspect, the method for synthesizing diphenylmethane comprising:

[0041] The mixture of benzene, benzyl chloride and the catalyst is heated, condensed and refluxed to undergo Friedel-Crafts alkylation reaction to obtain diphenylmethane.

[0042] In the diphenylmethane synthesis method provided by the present invention, the catalyst can be directly recovered and reused for more than 10 times after the Friedel-Crafts alkylation reaction, and the activity remains basically unchanged; in addition, the reaction yield of diphenylmethane in the diphenylmethane synthesis method reaches 95-97%, and the purity reaches 93-99%; in addition, the diphenylmethane synthesis method has low cost, short Friedel-Crafts alkylation reaction time, safe and risk-free, and high production capacity; in addition, the diphenylmethane synthesis method has high conversion rate, high selectivity, and basically no waste residue is generated.

[0043] Preferably, the molar ratio of benzene to benzyl chloride in the mixture is (0.5-5):1, for example, 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1 or 5:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] Preferably, the mass ratio of benzyl chloride to the catalyst in the mixture is 1:(0.05-0.32), for example, 1:0.05, 1:0.10, 1:0.15, 1:0.20, 1:0.25, 1:0.30 or 1:0.32, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] Preferably, the heating condensation reflux temperature is 60-85° C., and the time is 2.0-5.5 h.

[0046] The temperature of the heating condensation reflux in the present invention is 60-85°C, for example, it can be 60°C, 62°C, 65°C, 67°C, 70°C, 72°C, 75°C, 78°C, 80°C, 82°C or 85°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] The heating, condensing and reflux time described in the present invention is 2.0 to 5.5 hours, for example, it can be 2.0 hours, 2.2 hours, 2.5 hours, 3.0 hours, 3.2 hours, 3.5 hours, 3.8 hours, 4.0 hours, 4.2 hours, 4.5 hours, 5.0 hours, 5.2 hours or 5.5 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0048] Preferably, the diphenylmethane synthesis method further comprises catalyst recovery after the Friedel-Crafts alkylation reaction.

[0049] Preferably, the catalyst recovery method comprises filtering after the Friedel-Crafts alkylation reaction, and the obtained solid is the catalyst.

[0050] Preferably, the diphenylmethane synthesis method further comprises extracting diphenylmethane from the filtrate after the suction filtration, and the diphenylmethane extraction method comprises:

[0051] The filtrate obtained by the suction filtration is subjected to atmospheric distillation, and the fraction with a temperature of 90 to 170° C. is collected to obtain the benzene remaining after the reaction; the remaining solution after the atmospheric distillation is then subjected to oil pump negative pressure distillation, and the fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane.

[0052] Preferably, the pressure of the negative pressure distillation is -0.05 to -0.1 MPa, for example, it can be -0.05 MPa, -0.06 MPa, -0.07 MPa, -0.08 MPa, -0.09 MPa or -0.1 MPa, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] In a fourth aspect, the present invention provides diphenylmethane, which is obtained by the diphenylmethane synthesis method described in the third aspect.

[0054] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] (1) The present application provides a novel catalyst for preparing diphenylmethane, the catalyst comprising a metal organic framework material MIL-101 (X1, X2). The catalyst not only has a stable structure, but also does not react with by-products during the preparation of diphenylmethane, and has a low cost. Therefore, the catalyst has strong practicality, good recyclability, and high economy in the preparation of diphenylmethane. In addition, when the catalyst is used to prepare diphenylmethane, it exhibits a high conversion rate and selectivity, shortens the preparation time, increases production capacity, reduces the difficulty of post-processing, and improves safety.

[0057] (2) The preparation method of the catalyst provided in the present invention is simple, the preparation cost is low, and the safety of the preparation process is high;

[0058] (3) In the diphenylmethane synthesis method provided by the present invention, the catalyst can be directly recovered and reused for more than 10 times after the Friedel-Crafts alkylation reaction, and the activity remains basically unchanged; in addition, the reaction yield of diphenylmethane in the diphenylmethane synthesis method reaches 95-97%, and the purity reaches 93-99%; in addition, the diphenylmethane synthesis method has low cost, short Friedel-Crafts alkylation reaction time, safe and risk-free, and high production capacity; in addition, the diphenylmethane synthesis method has high conversion rate, high selectivity, and basically no waste residue is generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is the gas chromatography detection of the fraction obtained after the oil pump negative pressure distillation in Application Example 4. DETAILED DESCRIPTION

[0060] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0061] Example 1

[0062] This embodiment provides a catalyst for preparing diphenylmethane, wherein the catalyst includes a metal organic framework material MIL-101 (Fe, Zn), wherein the molar ratio of Fe to Zn in the metal organic framework material MIL-101 (Fe, Zn) is 1:0.1.

[0063] The preparation method of the catalyst is:

[0064] (1) 2.45 mmol of FeCl3·6H2O, 0.245 mol of ZnCl2, 1.24 mmol of terephthalic acid and 15 mL of N,N-dimethylformamide were mixed by ultrasonic treatment for 15 min to obtain a mixed solution;

[0065] (2) The mixed solution obtained in step (1) containing FeCl3, ZnCl2, terephthalic acid and N,N-dimethylformamide was placed in a 25 mL polytetrafluoroethylene-lined stainless steel reactor, and heat-treated at 100°C for 24 hours to obtain a brown solid by solid-liquid separation. The brown solid was then washed with ethanol at 60°C for 3 hours and dried at 180°C for 8 hours to remove the ethanol molecules adsorbed in the pores, thereby obtaining a brown solid with a specific surface area of ​​2874 m 2 / g and the micropore volume is 1.06cm 3 / g of the catalyst.

[0066] Example 2

[0067] This embodiment provides a catalyst for preparing diphenylmethane, wherein the catalyst includes a metal organic framework material MIL-101 (Fe, Zn), wherein the molar ratio of Fe to Zn in the metal organic framework material MIL-101 (Fe, Zn) is 1:0.2.

[0068] The preparation method of the catalyst is:

[0069] (1) 2.45 mmol of FeCl3·6H2O, 0.49 mol of ZnCl2, 1.24 mmol of terephthalic acid and 15 mL of N,N-dimethylformamide were mixed by ultrasonication for 15 min to obtain a mixed solution;

[0070] (2) The mixed solution obtained in step (1) containing FeCl3, ZnCl2, terephthalic acid and N,N-dimethylformamide was placed in a 25 mL polytetrafluoroethylene-lined stainless steel reactor and heat treated at 160°C for 5 h to obtain a brown solid by solid-liquid separation. The brown solid was then washed with ethanol at 60°C for 3 h, dried in an oven at 70°C for 30 min, and then dried in a vacuum environment at 150°C for 8 h to remove the ethanol molecules adsorbed in the pores, thereby obtaining a solid with a specific surface area of ​​2853 m 2 / g and the micropore volume is 1.09cm 3 / g of the catalyst.

[0071] Example 3

[0072] This embodiment provides a catalyst for preparing diphenylmethane, wherein the catalyst includes a metal organic framework material MIL-101 (Fe, Zn), wherein the molar ratio of Fe to Zn in the metal organic framework material MIL-101 (Fe, Zn) is 1:0.3.

[0073] The preparation method of the catalyst is:

[0074] (1) 2.45 mmol of FeCl3·6H2O, 0.735 mol of ZnCl2, 1.24 mmol of terephthalic acid and 15 mL of N,N-dimethylformamide were mixed by ultrasonication for 15 min to obtain a mixed solution;

[0075] (2) The mixed solution obtained in step (1) containing FeCl3, ZnCl2, terephthalic acid and N,N-dimethylformamide was placed in a 25 mL polytetrafluoroethylene-lined stainless steel reactor and heat treated at 130°C for 12 h to obtain a brown solid by solid-liquid separation. The brown solid was then washed with ethanol at 60°C for 3 h, dried in an oven at 70°C for 30 min, and then dried at 120°C for 8 h to remove the ethanol molecules adsorbed in the pores, thereby obtaining a solid with a specific surface area of ​​2912 m2 / g and the micropore volume is 1.02cm 3 / g of the catalyst.

[0076] Example 4

[0077] This embodiment provides a catalyst for preparing diphenylmethane, wherein the catalyst includes a metal organic framework material MIL-101 (Fe, Co), wherein the molar ratio of Fe to Co in the metal organic framework material MIL-101 (Fe, Co) is 1:0.2.

[0078] The preparation method of the catalyst is:

[0079] (1) 2.45 mmol of FeCl3·6H2O, 0.49 mol of CoCl2·6H2O, 1.24 mmol of terephthalic acid and 15 mL of N,N-dimethylformamide were mixed by ultrasonication for 15 min to obtain a mixed solution;

[0080] (2) The mixed solution obtained in step (1) containing FeCl3, CoCl2, terephthalic acid and N,N-dimethylformamide was placed in a 25 mL polytetrafluoroethylene-lined stainless steel reactor and heat treated at 150°C for 8 hours to obtain a brown solid by solid-liquid separation. The brown solid was then washed with ethanol at 60°C for 3 hours, dried in an oven at 70°C for 30 minutes, and then vacuum dried at 150°C for 8 hours to remove the ethanol molecules adsorbed in the pores, thereby obtaining a solid with a specific surface area of ​​2860 m 2 / g and the micropore volume is 1.07cm 3 / g of the catalyst.

[0081] Example 5

[0082] This embodiment provides a catalyst for preparing diphenylmethane, wherein the catalyst includes a metal organic framework material MIL-101 (Fe, Mn), wherein the molar ratio of Fe to Mn in the metal organic framework material MIL-101 (Fe, Mn) is 1:0.1.

[0083] The preparation method of the catalyst is:

[0084] (1) 2.45 mmol of FeCl3·6H2O, 0.245 mol of Mn(NO3)2·6H2O, 1.24 mmol of terephthalic acid and 15 mL of N,N-dimethylformamide were mixed by ultrasonication for 15 min to obtain a mixed solution;

[0085] (2) The mixed solution obtained in step (1) containing FeCl3, Mn(NO3)2, terephthalic acid and N,N-dimethylformamide was placed in a 25 mL polytetrafluoroethylene-lined stainless steel reactor and heat treated at 140°C for 18 hours to obtain a brown solid by solid-liquid separation. The brown solid was then washed with ethanol at 60°C for 3 hours, dried in an oven at 70°C for 30 minutes, and then vacuum dried at 140°C for 8 hours to remove the ethanol molecules adsorbed in the pores, thereby obtaining a solid with a specific surface area of ​​2863 m 2 / g and the micropore volume is 1.08cm 3 / g of the catalyst.

[0086] Example 6

[0087] This embodiment provides a catalyst for preparing diphenylmethane, wherein the catalyst includes a metal organic framework material MIL-101 (Al, Mn), wherein the molar ratio of Al to Mn in the metal organic framework material MIL-101 (Al, Mn) is 1:0.3.

[0088] The preparation method of the catalyst is:

[0089] (1) 2.45 mmol of AlCl3·6H2O, 0.735 mol of Mn(NO3)2·6H2O, 1.24 mmol of terephthalic acid and 15 mL of N,N-dimethylformamide were mixed by ultrasonication for 15 min to obtain a mixed solution;

[0090] (2) The mixed solution obtained in step (1) containing AlCl3, Mn(NO3)2, terephthalic acid and N,N-dimethylformamide was placed in a 25 mL polytetrafluoroethylene-lined stainless steel reactor and heat treated at 130°C for 20 h to obtain a brown solid by solid-liquid separation. The brown solid was then washed with ethanol at 60°C for 3 h, dried in an oven at 70°C for 30 min, and then vacuum dried at 90°C for 8 h to remove the ethanol molecules adsorbed in the pores, thereby obtaining a solid with a specific surface area of ​​2765 m 2 / g and the micropore volume is 1.02cm 3 / g of the catalyst.

[0091] Example 7

[0092] This embodiment provides a catalyst for preparing diphenylmethane, wherein the catalyst comprises a metal organic framework material MIL-101 (Al, Co), wherein the molar ratio of X1 to X2 in the metal organic framework material MIL-101 (X1, X2) is 1:0.2.

[0093] The preparation method of the catalyst is:

[0094] (1) 2.45 mmol of AlCl3, 0.49 mol of CoCl2, 1.24 mmol of terephthalic acid, and 15 mL of N,N-dimethylformamide were mixed by ultrasonication for 15 min to obtain a mixed solution;

[0095] (2) The mixed solution obtained in step (1) containing AlCl3, CoCl2, terephthalic acid and N,N-dimethylformamide was placed in a 25 mL polytetrafluoroethylene-lined stainless steel reactor and heat treated at 170°C for 10 h to obtain a brown solid by solid-liquid separation. The brown solid was then washed with ethanol at 70°C for 5 h and dried at 100°C for 8 h to remove the ethanol molecules adsorbed in the pores, thereby obtaining a solid having a specific surface area of ​​2751 m 2 / g and the micropore volume is 1.02cm 3 / g of the catalyst.

[0096] Example 8

[0097] This embodiment provides a catalyst for preparing diphenylmethane, the catalyst comprising a metal organic framework material MIL-101 (Fe, Zn), wherein the molar ratio of Fe to Zn in the metal organic framework material MIL-101 (Fe, Zn) is 1:0.05;

[0098] That is, except that the molar amount of ZnCl2 mixed in the catalyst is 0.1225 mol, the rest is the same as that in Example 1.

[0099] Example 9

[0100] This embodiment provides a catalyst for preparing diphenylmethane, the catalyst comprising a metal organic framework material MIL-101 (Fe, Zn), wherein the molar ratio of Fe to Zn in the metal organic framework material MIL-101 (Fe, Zn) is 1:0.4;

[0101] That is, the preparation method of the catalyst is the same as that of Example 1 except that the molar amount of ZnCl2 mixed is 0.98 mol.

[0102] Example 10

[0103] This embodiment provides a catalyst for preparing diphenylmethane, which is the same as that of Embodiment 1 except that the catalyst is heat treated at 70° C. in the preparation method.

[0104] Embodiment 11

[0105] This embodiment provides a catalyst for preparing diphenylmethane, which is the same as that of Embodiment 1 except that the catalyst is heat treated at 200° C. in the preparation method.

[0106] Comparative Example 1

[0107] This comparative example provides a catalyst for preparing diphenylmethane, wherein the catalyst is MIL-101(Fe).

[0108] The preparation method of the catalyst is:

[0109] (1) mixing 2.45 mmol of FeCl3·6H2O, 1.24 mmol of terephthalic acid, and 15 mL of N,N-dimethylformamide by ultrasonication for 15 min to obtain a mixed solution;

[0110] (2) The mixed solution obtained in step (1) containing FeCl3, terephthalic acid and N,N-dimethylformamide was placed in a 25 mL polytetrafluoroethylene-lined stainless steel reactor and heat treated at 110°C for 20 h to obtain a brown solid by solid-liquid separation. The brown solid was then washed with ethanol at 60°C for 3 h, dried in an oven at 70°C for 30 min, and then vacuum dried at 120°C for 8 h to remove the ethanol molecules adsorbed in the pores, thereby obtaining a solid having a specific surface area of ​​2700 m 2 / g and the micropore volume is 0.90cm 3 / g of the catalyst.

[0111] Comparative Example 2

[0112] This comparative example provides a catalyst for preparing diphenylmethane, wherein the catalyst is Fe-Zn / ZSM-5.

[0113] The preparation method of the catalyst is:

[0114] Weigh 15.1 g of Fe(NO3)3·9H2O and 2.35 g of Zn(NO3)2·6H2O, dissolve them in 300 g of deionized water, then add 20 g of ZSM-5 molecular sieve, heat to 100°C with stirring and react for 12 hours, cool and filter, wash the filter cake repeatedly with deionized water until it is neutral, then dry the filter cake in an oven at 150°C for 12 hours, and calcine the dried catalyst at 500°C for 5 hours in a muffle furnace to obtain the catalyst.

[0115] Comparative Example 3

[0116] This comparative example provides a catalyst for preparing diphenylmethane, wherein the catalyst is a ZSM-5 catalyst (commercially available).

[0117] Application Example 1

[0118] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 3, and the method for synthesizing diphenylmethane comprises:

[0119] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 2.78:1:0.05 is heated, condensed and refluxed at 60° C. for 4.0 hours to cause Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and the fraction with a temperature of 90 to 170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.08 MPa, and the fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane.

[0120] Application Example 2

[0121] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 2, and the method for synthesizing diphenylmethane comprises:

[0122] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 1.67:1:0.10 is heated, condensed and refluxed at 70° C. for 2 hours to cause Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and the fraction with a temperature of 90 to 170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.05 MPa, and the fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane.

[0123] Application Example 3

[0124] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 1, and the method for synthesizing diphenylmethane comprises:

[0125] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 0.56:1:0.30 is heated, condensed and refluxed at 85° C. for 3 hours to cause Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and the fraction with a temperature of 90 to 170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.1 MPa, and the fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane.

[0126] Application Example 4

[0127] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 1, and the method for synthesizing diphenylmethane comprises:

[0128] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 1.67:1:0.31 is heated, condensed and refluxed at 70° C. for 2 hours to cause Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and the fraction with a temperature of 90 to 170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.08 MPa, and the fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane.

[0129] Application Example 5

[0130] This application example provides a method for synthesizing diphenylmethane, except that the catalyst used is the catalyst obtained after filtration in Application Example 4 (i.e., the solid obtained after filtration is recycled to this application example as the catalyst in this application example);

[0131] The mass ratio of benzene, benzyl chloride and the catalyst in the mixture is 1.61:1:0.31, the heating condensation reflux temperature is 70° C., and the time is 2 h. Others are the same as those in Application Example 4.

[0132] Application Example 6

[0133] This application example provides a method for synthesizing diphenylmethane, except that the catalyst used is the catalyst obtained after filtration in Application Example 5 (i.e., the solid obtained after filtration is recycled to this application example as the catalyst in this application example);

[0134] The mass ratio of benzene, benzyl chloride and the catalyst in the mixture is 1.65:1:0.31, the heating condensation reflux temperature is 70° C., and the time is 2.5 h. Others are the same as those in Application Example 4.

[0135] Application Example 7

[0136] This application example provides a method for synthesizing diphenylmethane, except that the catalyst used is the catalyst obtained after filtration in Application Example 6 (i.e., the solid obtained after filtration is recycled to this application example as the catalyst in this application example);

[0137] The mass ratio of benzene, benzyl chloride and the catalyst in the mixture is 1.69:1:0.31, the heating condensation reflux temperature is 70° C., and the time is 2 h. Others are the same as those in Application Example 4.

[0138] Application Example 8

[0139] This application example provides a method for synthesizing diphenylmethane, except that the catalyst used is the catalyst obtained after filtration in Application Example 7 (i.e., the solid obtained after filtration is recycled to this application example as the catalyst in this application example);

[0140] The mass ratio of benzene, benzyl chloride and the catalyst in the mixture is 1.68:1:0.31, the heating condensation reflux temperature is 70° C., and the time is 3 hours. Others are the same as those in Application Example 4.

[0141] Application Example 9

[0142] This application example provides a method for synthesizing diphenylmethane, except that the catalyst used is the catalyst obtained after filtration in Application Example 8 (i.e., the solid obtained after filtration is recycled to this application example as the catalyst in this application example);

[0143] The mass ratio of benzene, benzyl chloride and the catalyst in the mixture is 1.64:1:0.31, the heating condensation reflux temperature is 70° C., and the time is 2 h. Others are the same as those in Application Example 4.

[0144] Application Example 10

[0145] This application example provides a method for synthesizing diphenylmethane, except that the catalyst used is the catalyst obtained after filtration in Application Example 9 (i.e., the solid obtained after filtration is recycled to this application example as the catalyst in this application example);

[0146] The mass ratio of benzene, benzyl chloride and the catalyst in the mixture is 1.65:1:0.31, the heating condensation reflux temperature is 70° C., and the time is 2 h, and the rest is the same as Example 4.

[0147] Application Example 11

[0148] This application example provides a method for synthesizing diphenylmethane, except that the catalyst used is the catalyst obtained after filtration in Application Example 10 (i.e., the solid obtained after filtration is recycled to this application example as the catalyst in this application example);

[0149] The mass ratio of benzene, benzyl chloride and the catalyst in the mixture is 1.64:1:0.31, the heating condensation reflux temperature is 70° C., and the time is 2 h, and the rest is the same as Example 4.

[0150] Application Example 12

[0151] This application example provides a method for synthesizing diphenylmethane, except that the catalyst used is the catalyst obtained after filtration in Application Example 11 (i.e., the solid obtained after filtration is recycled to this application example as the catalyst in this application example);

[0152] The mass ratio of benzene, benzyl chloride and the catalyst in the mixture is 1.68:1:0.32, the heating condensation reflux temperature is 70° C., and the time is 2.5 h. Others are the same as those in Example 4.

[0153] Application Example 13

[0154] This application example provides a method for synthesizing diphenylmethane, except that the catalyst used is the catalyst obtained after filtration in Application Example 12 (i.e., the solid obtained after filtration is recycled to this application example as the catalyst in this application example);

[0155] The mass ratio of benzene, benzyl chloride and the catalyst in the mixture is 1.66:1:0.31, the heating condensation reflux temperature is 70° C., and the time is 2 h, and the rest is the same as Example 4.

[0156] Application Example 14

[0157] This application example provides a method for synthesizing diphenylmethane, except that the catalyst used is the catalyst obtained after filtration in Application Example 13 (i.e., the solid obtained after filtration is recycled to this application example as the catalyst in this application example);

[0158] The mass ratio of benzene, benzyl chloride and the catalyst in the mixture is 1.64:1:0.31, the heating condensation reflux temperature is 70° C., and the time is 2 h, and the rest is the same as Example 4.

[0159] Application Example 15

[0160] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 4, and the method for synthesizing diphenylmethane comprises:

[0161] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 0.98:1:0.30 is heated, condensed and refluxed at 65° C. for 5.5 hours to cause Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and the fraction with a temperature of 90-170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.08, and the fraction with a temperature of 87-300° C. is collected to obtain the extracted diphenylmethane.

[0162] Application Example 16

[0163] This application example provides a method for synthesizing diphenylmethane. Except that the catalyst used is the catalyst obtained by performing diphenylmethane synthesis twice using the diphenylmethane synthesis method provided in Application Example 15 (that is, after synthesizing diphenylmethane using the diphenylmethane synthesis method in Application Example 15, the catalyst is reused, and after synthesizing diphenylmethane again using the diphenylmethane synthesis method in Application Example 15, the catalyst is added back for use in this application example), the rest is the same as that in Application Example 1.

[0164] Application Example 17

[0165] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 5, and the method for synthesizing diphenylmethane comprises:

[0166] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 0.55:1:0.30 is heated, condensed and refluxed at 80° C. for 4.5 hours to cause Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and a fraction with a temperature of 90-170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.08 MPa, and a fraction with a temperature of 87-300° C. is collected to obtain the extracted diphenylmethane.

[0167] Application Example 18

[0168] This application example provides a method for synthesizing diphenylmethane. Except that the catalyst used is the catalyst obtained by performing diphenylmethane synthesis twice using the diphenylmethane synthesis method provided in Application Example 17 (that is, after synthesizing diphenylmethane using the diphenylmethane synthesis method in Application Example 17, the catalyst is reused, and after synthesizing diphenylmethane again using the diphenylmethane synthesis method in Application Example 17, the catalyst is added back for use in this application example), the rest is the same as Application Example 17.

[0169] Application Example 19

[0170] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 6, and the method for synthesizing diphenylmethane comprises:

[0171] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 1.76:1:0.30 is heated, condensed and refluxed at 85° C. for 5.5 hours to cause Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and the fraction with a temperature of 90 to 170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.08 MPa, and the fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane.

[0172] Application Example 20

[0173] This application example provides a method for synthesizing diphenylmethane. Except that the catalyst used is the catalyst obtained by performing diphenylmethane synthesis twice using the diphenylmethane synthesis method provided in Application Example 19 (that is, after synthesizing diphenylmethane using the diphenylmethane synthesis method in Application Example 19, the catalyst is reused, and after synthesizing diphenylmethane again using the diphenylmethane synthesis method in Application Example 19, the catalyst is added back for use in this application example), the rest is the same as Application Example 19.

[0174] Application Example 21

[0175] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 7, and the method for synthesizing diphenylmethane comprises:

[0176] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 5:1:0.20 is heated, condensed and refluxed at 70° C. for 3.5 hours to cause Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and the fraction with a temperature of 90 to 170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.08 MPa, and the fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane.

[0177] Application Example 22

[0178] This application example provides a method for synthesizing diphenylmethane. Except that the catalyst used is the catalyst obtained by performing diphenylmethane synthesis twice using the diphenylmethane synthesis method provided in Application Example 11 (that is, after synthesizing diphenylmethane using the diphenylmethane synthesis method in Application Example 21, the catalyst is reused, and after synthesizing diphenylmethane again using the diphenylmethane synthesis method in Application Example 21, the catalyst is added back for use in this application example), the rest is the same as Application Example 21.

[0179] Application Example 23

[0180] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 8. Except for replacing the catalyst with the catalyst described in Example 8, the rest is the same as Application Example 3.

[0181] Application Example 24

[0182] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 9. Except for replacing the catalyst with the catalyst described in Example 9, the rest is the same as Application Example 3.

[0183] Application Example 25

[0184] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 10. Except for replacing the catalyst with the catalyst described in Example 10, the rest is the same as Application Example 3.

[0185] Application Example 26

[0186] This application example provides a method for synthesizing diphenylmethane using the catalyst described in Example 11. Except for replacing the catalyst with the catalyst described in Example 11, the rest is the same as Application Example 3.

[0187] Comparative application example 1

[0188] This comparative application example provides a method for synthesizing diphenylmethane using the catalyst described in Comparative Example 1, and the method for synthesizing diphenylmethane comprises:

[0189] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 0.80:1:0.30 is heated, condensed and refluxed at 85° C. for 3.5 hours while being stirred to cause Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and a fraction with a temperature of 90 to 170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.08 MPa, and a fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane.

[0190] Comparative Application Example 2

[0191] This comparative application example provides a method for synthesizing diphenylmethane. Except that the catalyst used is the catalyst obtained after filtration in comparative application example 1 (i.e., the solid obtained after filtration is recycled into this comparative application example as the catalyst in this comparative application example), the rest is the same as comparative application example 1.

[0192] Comparative Application Example 3

[0193] This comparative application example provides a method for synthesizing diphenylmethane. Except that the catalyst used is the catalyst obtained after filtration in comparative application example 2 (i.e., the solid obtained after filtration is recycled into this comparative application example as the catalyst in this comparative application example), the rest is the same as comparative application example 1.

[0194] Comparative Application Example 4

[0195] This comparative application example provides a method for synthesizing diphenylmethane using the catalyst described in Comparative Example 2, and the method for synthesizing diphenylmethane comprises:

[0196] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 2.68:1:0.22 is heated, condensed and refluxed at 80° C. for 4.5 hours while being stirred to cause a Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and a fraction with a temperature of 90 to 170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.08 MPa, and a fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane.

[0197] Comparative Application Example 5

[0198] This comparative application example provides a method for synthesizing diphenylmethane. Except that the catalyst used is the catalyst obtained by performing diphenylmethane synthesis twice using the diphenylmethane synthesis method provided in Comparative Application Example 4 (that is, after synthesizing diphenylmethane using the diphenylmethane synthesis method in Comparative Application Example 4, the catalyst is reused, and after synthesizing diphenylmethane again using the diphenylmethane synthesis method in Comparative Application Example 4, the catalyst is added back for use in this application example), the rest is the same as Comparative Application Example 4.

[0199] Comparative Application Example 6

[0200] This comparative application example provides a method for synthesizing diphenylmethane using the catalyst described in Comparative Example 3, and the method for synthesizing diphenylmethane comprises:

[0201] In a 500 ml three-necked flask equipped with a thermometer and a condenser, a mixture of benzene, benzyl chloride and the catalyst in a mass ratio of 1.98:1:0.33 is heated, condensed and refluxed at 80° C. for 5 hours while being stirred to cause a Friedel-Crafts alkylation reaction, and then cooled to room temperature and filtered, the solid obtained by filtration is the catalyst, and the filtrate obtained by filtration is subjected to atmospheric distillation, and a fraction with a temperature of 90 to 170° C. is collected to obtain the remaining benzene after the reaction, which is reused as a raw material; and the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation at a pressure of -0.08 MPa, and a fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane.

[0202] Comparative Application Example 7

[0203] This comparative application example provides a method for synthesizing diphenylmethane. Except that the catalyst used is the catalyst obtained by performing diphenylmethane synthesis twice using the diphenylmethane synthesis method provided in Comparative Application Example 6 (that is, after synthesizing diphenylmethane using the diphenylmethane synthesis method in Comparative Application Example 6, the catalyst is reused, and after synthesizing diphenylmethane again using the diphenylmethane synthesis method in Comparative Application Example 6, the catalyst is added back for use in this application example), the rest is the same as Comparative Application Example 6.

[0204] The diphenylmethane synthesis method provided in the above application examples and comparative application examples was used to perform gas chromatography detection (GC detection) on the fraction at 87-300°C, and the yield and purity of diphenylmethane were as shown in Table 1. Among them, the gas chromatography detection of the fraction obtained after the negative pressure distillation of the oil pump in Application Example 4 is as shown in Table 1. Figure 1 shown.

[0205] Table 1

[0206]

[0207]

[0208] From Table 1, we can get:

[0209] (1) When diphenylmethane is synthesized by the diphenylmethane synthesis method provided in Application Examples 1 to 4, 15, 17, 19, and 21, the time used is short, and diphenylmethane has a high yield and purity, indicating that when diphenylmethane is prepared by the catalyst provided in this application, a high conversion rate and selectivity are exhibited, and the preparation time is shortened, and the production capacity is increased; in addition, the difficulty of post-processing is low and the safety is high when the catalyst provided in this application is used to prepare diphenylmethane;

[0210] (2) Through the comparison between application examples 4 to 14, the comparison between 15 to 16, the comparison between 17 to 18, the comparison between 19 to 20, the comparison between 21 to 22, the comparison between comparative application examples 1 to 3, the comparison between comparative application examples 4 to 5, and the comparison between comparative application examples 6 to 7, it can be seen that the catalyst provided in the present application, when preparing diphenylmethane, even if it is reused many times, still shows a high conversion rate and selectivity in the synthesis process of diphenylmethane, thereby maintaining the yield and purity of diphenylmethane at a high level. This is because the metal organic The framework material MIL-101 (X1, X2) is used as a catalyst. The catalyst not only has a stable structure, but also does not react with by-products in the process of preparing diphenylmethane, and has a low cost. Therefore, it has strong practicality, good recyclability, and high economy in the preparation of diphenylmethane. However, when the MIL-101 (Fe) catalyst, the Fe-Zn / ZSM-5 catalyst, and the ZSM-5 catalyst (commercially available) are reused, the conversion rate and selectivity of the diphenylmethane synthesis process drop sharply, thereby causing a sharp drop in the yield and purity of diphenylmethane.

[0211] (3) By comparing Application Example 3 with Application Examples 23 and 24, it can be seen that the molar ratio of X1 to X2 in the metal organic framework material MIL-101 (X1, X2) of the present invention affects the performance of the catalyst, thereby affecting the yield and purity of diphenylmethane; when the molar ratio of X1 to X2 is 1:(0.1-0.3), the catalyst exhibits more excellent performance, thereby making diphenylmethane have a higher yield and purity. This is because the catalyst is more conducive to initiating carbon cations, attacking the benzene ring, forming complex intermediates, improving the conversion rate of the reaction and the selectivity of the product, thereby improving the yield and purity of diphenylmethane;

[0212] (4) By comparing Application Example 3 with Application Examples 25 and 26, it can be seen that the temperature of the heat treatment in the present invention affects the performance of the catalyst, thereby affecting the yield and purity of diphenylmethane; when the temperature of the heat treatment is 100-170°C, the catalyst exhibits more excellent performance, thereby making diphenylmethane have a higher yield and purity. This is because at a suitable heat treatment temperature, the dispersion of metal ions in the catalyst is more uniform, and the catalytic performance is further improved; in addition, a suitable heat treatment temperature can activate the catalyst, thereby improving the yield and purity of diphenylmethane.

[0213] The above description is only a specific implementation mode 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 thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A catalyst for preparing diphenylmethane, characterized in that: The catalyst comprises a metal organic framework material MIL-101 (X1, X2), wherein X1 is iron and / or aluminum, and X2 is any one of zinc, manganese or cobalt or a combination of at least two thereof.

2. The catalyst according to claim 1, characterized in that The molar ratio of X1 to X2 in the metal organic framework material MIL-101 (X1, X2) is 1:(0.1-0.3); Preferably, X1 is iron and X2 is zinc; Preferably, the specific surface area of ​​the catalyst is 2700-2950m 2 / g; Preferably, the micropore volume of the catalyst is 1.02 to 1.09 cm 3 / g.

3. A method for preparing the catalyst according to claim 1 or 2, characterized in that: The preparation method comprises: The catalyst is obtained by heat-treating a mixed solution containing a first metal salt, a second metal salt, terephthalic acid and N,N-dimethylformamide.

4. The preparation method according to claim 3, characterized in that: The first metal salt comprises an iron salt and / or an aluminum salt; Preferably, the second metal salt comprises any one of zinc salt, manganese salt or cobalt salt, or a combination of at least two of them.

5. The preparation method according to claim 3 or 4, characterized in that: The heat treatment is carried out at a temperature of 100 to 170° C. and for a time of 5 to 24 hours.

6. The preparation method according to any one of claims 3 to 5, characterized in that: The preparation method further includes post-treatment after the heat treatment, and the post-treatment includes: solid-liquid separation to obtain a brown solid, and then washing and drying the obtained brown solid in sequence to obtain the catalyst.

7. A method for synthesizing diphenylmethane using the catalyst according to claim 1 or 2, characterized in that: The diphenylmethane synthesis method comprises: The mixture of benzene, benzyl chloride and the catalyst is heated, condensed and refluxed to undergo Friedel-Crafts alkylation reaction to obtain diphenylmethane.

8. The method for synthesizing diphenylmethane according to claim 7, characterized in that: The molar ratio of benzene to benzyl chloride in the mixture is (0.5-5):1; Preferably, the mass ratio of benzyl chloride to the catalyst in the mixture is 1:(0.05-0.32); Preferably, the heating condensation reflux temperature is 60-85° C., and the time is 2.0-5.5 h.

9. The method for synthesizing diphenylmethane according to claim 7 or 8, characterized in that: The diphenylmethane synthesis method further comprises recovering the catalyst after the Friedel-Crafts alkylation reaction; Preferably, the catalyst recovery method comprises filtering after the Friedel-Crafts alkylation reaction, and the obtained solid is the catalyst; Preferably, the diphenylmethane synthesis method further comprises extracting diphenylmethane from the filtrate after the suction filtration, and the diphenylmethane extraction method comprises: The filtrate obtained by the suction filtration is subjected to atmospheric distillation, and the fraction with a temperature of 90 to 170° C. is collected to obtain the benzene remaining after the reaction; the remaining solution after the atmospheric distillation is subjected to oil pump negative pressure distillation, and the fraction with a temperature of 87 to 300° C. is collected to obtain the extracted diphenylmethane; Preferably, the pressure of the negative pressure distillation is -0.05 to -0.1 MPa.

10. A diphenylmethane, characterized in that The diphenylmethane is obtained by the diphenylmethane synthesis method according to any one of claims 7 to 9.

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