Metal organic framework material with sulfonyl benzene ring structure, preparation method and application thereof, and carboxylic acid esterification method

Abstract

The present invention relates to the technical field of metal organic framework materials, and discloses a metal organic framework material having a sulfonyl benzene ring structure, a preparation method and application thereof, and a method for esterification of carboxylic acids. The ligand of the metal organic framework material is provided by a substance having a structure as shown in formula (1), and the coordination metal M is selected from one of Zr, Cr and Al; in formula (1), M' is selected from one of H, Li, Na, K, Cs, Ca and Mg. The metal organic framework material provided by the present invention has excellent specific surface area, pore volume, pore diameter and acid density, and when used in esterification reactions, especially esterification reactions of carboxylic acids and alcohols, it can effectively improve the esterification rate of carboxylic acid esterification reactions. It has broad application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of metal organic framework materials, and in particular to a metal organic framework material having a sulfonyl benzene ring structure, a preparation method and application thereof, and a carboxylic acid esterification method. Background Art

[0002] Metal-Organic Frameworks (MOFs), also known as coordination polymers, are crystalline porous metal-organic materials with a periodic network structure formed by interconnecting inorganic metals with organic ligands with bridging effects. It is different from traditional inorganic porous compounds and organic compounds. It has the characteristics of both inorganic and organic compound materials. Due to its high porosity, high specific surface area, adjustable pores, structural diversity and other advantages, it has broad application prospects in gas storage (hydrogen storage), adsorption and separation, multiple catalysis, optoelectronics and other fields. The research and related applications of MOFs materials have become a hot topic in the international frontier research. For example, Yaghi O Metal. Science, 2013, 341, 974.

[0003] The synthesis of acidic metal organic framework compound materials currently mainly adopts a mixed stirring synthesis method based on the sulfonation method. Since chlorosulfonic acid is a hydrophilic sulfonate, the obtained sulfonated metal organic framework compound material easily adsorbs water during the reaction, resulting in low activity and cycle performance. Therefore, in order to solve the above problems and solve the diversity of reaction requirements, it is of great significance to design and synthesize a strongly acidic metal organic framework compound. Green Chem., 2014, 16, 2490–2499 and CN110903489A both use MOFs materials to react with sulfonic acid to generate acidic MOFs materials. The specific structure of MOFs cannot be verified, nor can the maximum acid density be guaranteed, and it is not a very fixed value.

[0004] As an important class of organic chemical products and organic chemical raw materials, dimethyl terephthalate (DMT) is a monomer of polyester. Dimethyl terephthalate is mainly used to make polyester resins, and then to make films and fibers, as well as high-strength polyester insulating varnishes. Polyester films are mainly used as electrical insulation materials and for making films (such as base materials for movie films, X-ray films, and electronic computer tapes). The most common use of polyester resins is to make fibers for fabrics, fishing nets, carpets, tire cords, etc. It can also be used to produce plasticizer dioctyl terephthalate.

[0005] The traditional process for producing dimethyl terephthalate is to esterify terephthalic acid and methanol under the catalysis of sulfuric acid. In addition, p-xylene is also oxidized and esterified to produce dimethyl terephthalate. The sulfuric acid esterification method has technical problems such as low raw material conversion rate, heavy pollution, and low product purity; the Weiden four-stage method using p-xylene oxidation has defects such as a relatively long route and by-product angle. It is of great significance to find a better synthesis method.

[0006] Therefore, there is an urgent need to develop a catalyst with excellent performance for the synthesis of dimethyl phthalate and its derivatives. In addition, improving the reaction efficiency and inhibiting the formation of by-products have always been important work directions in the future. Summary of the invention

[0007] The purpose of the present invention is to overcome the technical problems in the prior art of the catalysts used for synthesizing dimethyl terephthalate and its derivatives, such as excessive side reactions, serious environmental pollution, poor catalytic activity of solid acid catalysts and acidic cation exchange resin catalysts, and low ester selectivity.

[0008] In order to achieve the above-mentioned object, the first aspect of the present invention provides a metal organic framework material having a sulfonylbenzene ring structure, wherein the ligand of the metal organic framework material is provided by a substance having a structure as shown in formula (1), and the coordination metal M is selected from one of Zr, Cr and Al; in formula (1), M' is selected from one of H, Li, Na, K, Cs, Ca and Mg;

[0009]

[0010] A second aspect of the present invention provides a method for preparing a metal organic framework material having a sulfonyl benzene ring structure, the method comprising the following steps:

[0011] (1) in the presence of a first solvent and an optional acid, subjecting the compound represented by formula (3) to a coordination reaction with a metal source to be coordinated;

[0012] (2) optionally, acidifying the product of the coordination reaction;

[0013] Wherein, in formula (3), M" is selected from one of Li, Na, K, Cs, Ca and Mg; the metal in the metal source to be coordinated is selected from one of Zr, Cr and Al;

[0014]

[0015] The third aspect of the present invention provides an application of the metal organic framework material described in the first aspect or the method described in the second aspect in an esterification reaction, in particular in carboxylic acid esterification.

[0016] The fourth aspect of the present invention provides a method for esterification of carboxylic acid, the method comprising: contacting carboxylic acid with alcohol in the presence of a catalyst; the catalyst is the metal organic framework material described in the first aspect;

[0017] Alternatively, the metal organic framework material is prepared according to the method described in the second aspect, and the carboxylic acid is contacted with the alcohol in the presence of the metal organic framework material.

[0018] Compared with the prior art, the technical solution provided by the present invention has at least the following advantages:

[0019] (1) The metal organic framework material provided by the present invention has excellent specific surface area, pore volume, pore size and acid density. When used in esterification reactions, especially the esterification reaction of carboxylic acid and alcohol, it can effectively inhibit the occurrence of side reactions even at relatively low reaction temperatures and effectively improve the esterification rate of the carboxylic acid esterification reaction.

[0020] (2) The present invention also provides a method for preparing a metal organic framework material having a sulfonyl benzene ring structure. The method adopts a method of first constructing an organic ligand framework and then coordinating with a metal center, so that the structure of the prepared metal organic framework material is stable (compared with traditional acidic resin catalysts, the thermal stability is strong. The metal organic framework material provided by the present invention is structurally stable below 350°C, see Figure 4 ); and, in the method provided by the present invention, there is no large amount of waste acid and pollutants such as SO2 during the reaction process, and it is environmentally friendly. In addition, in a preferred embodiment of the present invention, for example, when preparing the compound represented by formula (3), a solid-phase catalytic metal halide is used, and both the raw material and the product can be dissolved in the solvent, so there is also an advantage of easy separation. At the same time, the method provided by the present invention has the advantages of simple steps, convenient operation, and the use of a fixed-bed heterogeneous catalytic reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the XRD pattern of the metal organic framework material prepared in Example 1;

[0022] Figure 2 is the XRD pattern of the metal organic framework material prepared in Example 2;

[0023] Figure 3 is the XRD pattern of the metal organic framework material prepared in Example 3;

[0024] Figure 4 This is the thermal stability curve of the metal organic framework material prepared in Example 1. DETAILED DESCRIPTION

[0025] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0026] The first aspect of the present invention provides a metal organic framework material having a sulfonylbenzene ring structure, wherein the ligand of the metal organic framework material is provided by a substance having a structure as shown in formula (1), and the coordination metal M is selected from one of Zr, Cr and Al; in formula (1), M' is selected from one of H, Li, Na, K, Cs, Ca and Mg;

[0027]

[0028] According to some embodiments of the present invention, the metal organic framework material has a structure as shown in formula (2):

[0029]

[0030] According to some embodiments of the present invention, the specific surface area of ​​the metal organic framework material is 10-500m 2 / g, the total pore volume is 1×10 -3 -10×10 -3 cm 3 / g, average pore radius ≤5nm.

[0031] Preferably, the specific surface area of ​​the metal organic framework material is 80-400 m 2 / g, the total pore volume is 2×10 -3 -5×10 -3 cm 3 / g, and the average pore radius is 0.2-1nm.

[0032] The second aspect of the present invention provides a method for preparing the aforementioned metal organic framework material having a sulfonyl benzene ring structure, the method comprising the following steps:

[0033] (1) in the presence of a first solvent and an optional acid, subjecting the compound represented by formula (3) to a coordination reaction with a metal source to be coordinated;

[0034] (2) optionally, acidifying the product of the coordination reaction;

[0035] Wherein, in formula (II), M" is selected from one of Li, Na, K, Cs, Ca and Mg; the metal in the metal source to be coordinated is selected from one of Zr, Cr and Al;

[0036]

[0037] According to some embodiments of the present invention, in step (1), the conditions of the coordination reaction may include: a temperature of 80-200° C., preferably 100-150° C.; and a time of 5-30 h, preferably 10-24 h.

[0038] According to some embodiments of the present invention, the molar ratio of the compound represented by formula (3), the metal source to be coordinated, the acid and the first solvent can be 1: (1.5-5): (0-20): (1-100); preferably 1: (2-3): (0-10): (2-50).

[0039] In the present invention, in the coordination reaction, the addition of an acid (such as acetic acid) can act as a template agent to form catalytically active vacancies on the crystal surface, which can be further used for later modification.

[0040] According to some embodiments of the present invention, the metal source to be coordinated can be selected from one of ZrCl4, Cr(NO3)3 6H2O, AlO4(OH)2 and Zn(NO3)2; preferably selected from one of ZrCl4, Cr(NO3)36H2O and AlO4(OH)2.

[0041] According to some embodiments of the present invention, the first solvent may be selected from at least one of N,N-dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone, preferably N,N-dimethylformamide.

[0042] According to some embodiments of the present invention, the acid may be selected from hydrochloric acid and / or a C1-C4 monobasic organic acid, preferably at least one selected from hydrochloric acid, formic acid and acetic acid.

[0043] In the present invention, there is no particular limitation on the post-treatment operation of the coordination reaction in step (1), as long as it can meet the requirements of the present invention. For example, it can be carried out in the following manner: the material of the coordination reaction is centrifuged and filtered (1000-10000rpm), and washed with a washing solvent (for example, DMF and methanol in sequence) (which can be repeated 2-5 times); then dried at 90-180°C for 5-10h. There is no particular limitation on the type and amount of the washing solvent, as long as it can meet the requirements of the present invention.

[0044] According to some embodiments of the present invention, in step (1), the step of preparing the compound represented by formula (3) comprises: in the presence of a second solvent and a metal halide, subjecting terephthalic acid to a substitution reaction with chlorosulfonate to obtain the compound represented by formula (3).

[0045] According to some embodiments of the present invention, the conditions of the substitution reaction may include: a temperature of 30-100° C., preferably 40-80° C.; and a time of 5-30 h, preferably 10-24 h.

[0046] According to some embodiments of the present invention, the molar ratio of terephthalic acid, chlorosulfonate and metal halide can be 1:(0.5-2):(0.01-1), preferably 1:(0.8-1.2):(0.05-0.5).

[0047] According to some embodiments of the present invention, the metal halide is selected from at least one of RuCl3, FeCl3, AlCl3 and PdCl2, preferably selected from at least one of RuCl3, FeCl3 and AlCl3.

[0048] According to some embodiments of the present invention, the second solvent is selected from at least one of dichloromethane, 1,2-dichloromethane and chloroform; preferably dichloromethane.

[0049] According to some embodiments of the present invention, relative to 1 g of terephthalic acid, the amount of the second solvent is 20-100 mL, preferably 30-80 mL.

[0050] There is no particular limitation on the post-treatment operation of the above-mentioned substitution reaction, as long as it can meet the requirements of the present invention. Preferably, before obtaining the compound represented by formula (3), the following post-treatment operation can be performed: the material of the substitution reaction is filtered and washed with a washing solvent (for example, dichloromethane and methanol in sequence) (which can be repeated 2-5 times); then dried at 60-100°C for 5-10h. There is no particular limitation on the type and amount of the washing solvent, as long as it can meet the requirements of the present invention.

[0051] According to some embodiments of the present invention, in step (2), the acidification is performed in the presence of an inorganic acid, and the concentration of the inorganic acid is 0.1-18.4 mol / L, preferably 1-10 mol / L.

[0052] In the present invention, the inorganic acid can be selected from at least one of hydrochloric acid, sulfuric acid and nitric acid, preferably hydrochloric acid. Among them, nitric acid is preferably dilute nitric acid (the concentration can be 0.1-1 mol / L). Sulfuric acid is preferably dilute sulfuric acid (the concentration can be 0.1-5 mol / L).

[0053] According to some embodiments of the present invention, the acidification conditions may include: a temperature of -10°C to -100°C, preferably 0°C to 50°C; and a time of 5-30h, preferably 10-24h.

[0054] According to some embodiments of the present invention, the amount of the inorganic acid used may be 1-10 mol, preferably 1-5 mol, per mol of the compound represented by formula (3).

[0055] Those skilled in the art will understand that after acidification, M" in formula (3) is converted from metal to H, thereby obtaining a strongly acidic sulfonylbenzene ring metal organic framework material.

[0056] In the present invention, before obtaining the metal organic framework material, the following post-treatment operation can be performed: the acidified material system is filtered and the obtained solid is washed with water (which can be repeated 2-5 times). There is no particular limitation on the amount of water used for washing.

[0057] The third aspect of the present invention provides an application of the metal organic framework material described in the first aspect or the method described in the second aspect in an esterification reaction, in particular in carboxylic acid esterification.

[0058] The fourth aspect of the present invention provides a method for esterification of carboxylic acid, the method comprising: contacting carboxylic acid with alcohol in the presence of a catalyst; the catalyst is the metal organic framework material described in the first aspect;

[0059] Alternatively, the metal organic framework material is prepared according to the method described in the second aspect, and the carboxylic acid is contacted with the alcohol in the presence of the metal organic framework material.

[0060] According to some embodiments of the present invention, the contact conditions may include: temperature of 20-200°C, preferably 50-150°C; pressure of 0.1-1MPa, preferably 0.2-0.5MPa; time of 20-80h, preferably 30-60h; weight space velocity of carboxylic acid of 1-5h -1 , preferably 2-3h -1 .

[0061] According to some embodiments of the present invention, the molar ratio of the carboxylic acid to the alcohol may be 1:(1-100), preferably 1:(2-10).

[0062] The carboxylic acid is selected from C2-C20 mono- or poly-carboxylic acids, preferably C2-C10 mono- or poly-carboxylic acids.

[0063] The alcohol is selected from C1-C10 monohydric alcohols, preferably C1-C6 monohydric alcohols.

[0064] The present invention will be described in detail below through examples.

[0065] The raw materials and solvents used in the following examples and comparative examples were all commercially available;

[0066] The specific surface area, total pore volume and average pore radius were measured by a nitrogen physical adsorption instrument (purchased from Anton Paar-Kantara Instruments, model Autosorb-iQ).

[0067] Thermogravimetric data were measured by a thermal analyzer (purchased from Mettle-Toledo, DGA-DSC1 thermal analyzer).

[0068] Example 1

[0069] (1) 1.04 g of RuCl3, 16.6 g of terephthalic acid, 16.5 g of sodium chlorosulfonate and 1000 mL of dichloromethane were added to a reaction flask, and the substitution reaction was carried out at 50°C for 24 h. The solid was filtered and washed three times with 100 mL of dichloromethane and three times with 100 mL of methanol. The solid was dried at 80°C for 8 h to obtain 24.9 g of a white powder (confirmed by nuclear magnetic resonance detection to be the compound represented by formula (3), wherein M" is Na). Thereafter, ZrCl4, the compound represented by formula (3), DMF and acetic acid were subjected to coordination reaction (calcination crystallization) at a molar ratio of 2.5:1:40:6 at 120°C for 24 h. The reaction was centrifuged and filtered at 4000 rpm. The solid was washed three times with 50 mL of DMF and three times with 50 mL of methanol. The solid was dried at 105°C for 8 h to obtain a white solid (metal organic framework material).

[0070] (2) Add 26 mL of 5 mol / L hydrochloric acid to the white solid obtained in step (1), and acidify under stirring at 25° C. for 12 h; filter, and rinse the solid three times with 50 mL of water to obtain an acidified metal organic framework material (Zr is the metal center).

[0071] Among them, the XRD spectrum of the acidified metal organic framework material prepared in this example is shown in Figure 1 ;

[0072] The specific surface area is 374.3m 2 / g, total pore volume = 2.357 × 10 -3 cm 3 / g, and the average pore radius is 0.6nm.

[0073] Example 2

[0074] (1) 1.04 g of RuCl3, 16.6 g of terephthalic acid, 16.5 g of sodium chlorosulfonate and 1000 mL of dichloromethane were added to a reaction flask, and the substitution reaction was carried out at 50°C for 24 h. The solid was filtered and washed three times with 100 mL of dichloromethane and three times with 100 mL of methanol. The solid was dried at 80°C for 8 h to obtain 24.9 g of a white powder (confirmed by nuclear magnetic resonance detection to be the compound represented by formula (3), wherein M" is Na). Thereafter, Cr(NO3)3 6H2O, the compound represented by formula (3), DMF and acetic acid were subjected to coordination reaction (calcination crystallization) at a molar ratio of 2.5:1:40:6 at 100°C for 24 h. The reaction was centrifuged and filtered at 5000 rpm. The solid was washed three times with 50 mL of DMF and three times with 50 mL of methanol. The solid was dried at 120°C for 6 h to obtain a white solid (metal organic framework material).

[0075] (2) Add 55 mL of 2 mol / L hydrochloric acid to the white solid obtained in step (1), and acidify under stirring at 25° C. for 20 h; filter, and rinse the solid with 50 mL of water three times to obtain an acidified metal organic framework material (Cr is the metal center).

[0076] Among them, the XRD spectrum of the acidified metal organic framework material prepared in this example is shown in Figure 2 ;

[0077] The specific surface area is 362.7m 2 / g, total pore volume = 2.416 × 10 -3 cm 3 / g, and the average pore radius is 0.6nm.

[0078] Example 3

[0079] (1) 1.04 g of RuCl3, 16.6 g of terephthalic acid, 16.5 g of sodium chlorosulfonate and 1000 mL of dichloromethane were added to a reaction flask, and the substitution reaction was carried out at 50°C for 24 h. The solid was filtered and washed three times with 100 mL of dichloromethane and three times with 100 mL of methanol. The solid was dried at 80°C for 8 h to obtain 24.9 g of a white powder (confirmed by nuclear magnetic resonance detection to be the compound represented by formula (3), wherein M" is Na). Thereafter, AlO4(OH)2, the compound represented by formula (3), DMF and acetic acid were subjected to coordination reaction (calcination crystallization) at a molar ratio of 3:1:50:10 at 150°C for 24 h. The reaction was centrifuged and filtered at 6000 rpm. The solid was washed three times with 50 mL of DMF and three times with 50 mL of methanol. The solid was dried at 130°C for 5 h to obtain a white solid (metal organic framework material).

[0080] (2) Add 10 mL of 11 mol / L hydrochloric acid to the white solid obtained in step (1), and acidify under stirring at 50° C. for 6 h; filter, and rinse the solid three times with 50 mL of water to obtain an acidified metal organic framework material (Al is the metal center).

[0081] Among them, the XRD spectrum of the acidified metal organic framework material prepared in this embodiment is shown in Figure 3 ;

[0082] The specific surface area is 351.6m 2 / g, total pore volume = 2.763 × 10 -3 cm 3 / g, and the average pore radius is 0.6nm.

[0083] Comparative Example 1

[0084] In a 100 mL three-necked flask, add 1.0 g of UIO-66 (Zr), 1 g of chlorosulfonic acid and 60 mL of dichloromethane, heat to 30 ° C under magnetic stirring, add 0.5 g of AlCl3 as an alkylation catalyst, react at 30 ° C for 1 hour, filter and wash, and dry at 80 ° C overnight. A white solid is obtained, which is the metal organic framework material.

[0085] Test Example 1

[0086] The metal organic framework material (Zr as the metal center) prepared in Example 1 was used as a catalyst to evaluate its catalytic performance in the esterification reaction of terephthalic acid and methanol. 5.0 g of the metal organic framework material (Zr as the metal center) was loaded into a stainless steel fixed bed reactor with an inner diameter of 8 mm. The reaction temperature was 95° C., the reaction pressure was adjusted to 0.3 MPa using nitrogen, and the weight space velocity of terephthalic acid was 1 h -1 The molar ratio of methanol to terephthalic acid was 2:1, the reaction time was 50 hours, the conversion rate of terephthalic acid was 94.4%, and the selectivity of dimethyl terephthalate was 98.2%.

[0087] Test Example 2

[0088] The metal organic framework material (Cr as the metal center) prepared in Example 2 was used as a catalyst to evaluate its catalytic performance in the esterification reaction of terephthalic acid and methanol. 5.0 g of the metal organic framework material was loaded into a stainless steel fixed bed reactor with an inner diameter of 8 mm. The reaction temperature was 120° C., the reaction pressure was adjusted to 0.3 MPa using nitrogen, and the weight space velocity of terephthalic acid was 3 h -1 The molar ratio of methanol to terephthalic acid was 8:1, the reaction time was 50 hours, the conversion rate of terephthalic acid was 97.7%, and the selectivity of dimethyl terephthalate was 96.5%.

[0089] Test Example 3

[0090] The metal organic framework material (Al as the metal center) prepared in Example 3 was used as a catalyst to evaluate its catalytic performance in the esterification reaction of terephthalic acid and methanol. 5.0 g of the metal organic framework material was loaded into a stainless steel fixed bed reactor with an inner diameter of 8 mm. The reaction temperature was 110° C., the reaction pressure was adjusted to 0.3 MPa using nitrogen, and the weight space velocity of terephthalic acid was 4 h -1 The molar ratio of methanol to terephthalic acid was 8:1, the reaction time was 50 hours, the conversion rate of terephthalic acid was 96.9%, and the selectivity of dimethyl terephthalate was 95.7%.

[0091] Test Example 4

[0092] The test was carried out in the manner of Test Example 2, except that the metal organic framework material prepared in Example 2 was replaced by an equal amount of the metal organic framework material prepared in Comparative Example 1.

[0093] Finally, the terephthalic acid conversion was 85.9% and the selectivity to dimethyl terephthalate was 84.5%.

[0094] Test Example 5

[0095] The test was carried out in the manner of Test Example 2, except that the metal organic framework material prepared in Example 2 was replaced by an equal amount of UIO-66 (Zr) metal organic framework compound.

[0096] Finally, the terephthalic acid conversion was 17.3% and the selectivity to dimethyl terephthalate was 71.4%.

[0097] Test Example 6

[0098] The method of Test Example 2 was followed, except that an equal amount of acidic cation exchange resin (D009, Kairui Environmental Protection Technology Co., Ltd.) was used instead of the metal organic framework material prepared in Example 2.

[0099] Finally, the conversion of terephthalic acid was 91.3%, and the selectivity of dimethyl terephthalate was 93.3%.

[0100] From the above results, it can be seen that the metal organic framework material of the present invention (under the same reaction conditions and catalyst dosage) has higher reaction activity and selectivity when used for carboxylic acid esterification.

[0101] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An application of a metal organic framework material having a sulfonyl benzene ring structure in improving the selectivity of dimethyl terephthalate in a terephthalate esterification reaction, characterized in that: The ligand of the metal organic framework material is provided by a substance having a structure as shown in formula (1), and the coordination metal M is selected from one of Zr, Cr and Al; in formula (1), M' is selected from one of H, Li, Na, K and Cs; （1）。 2. The use according to claim 1, wherein: The metal organic framework material has a structure as shown in formula (2): （2）。 3. The use according to claim 1 or 2, wherein: The specific surface area of ​​the metal organic framework material is 10-500m 2 / g, the total pore volume of the metal organic framework material is 1×10 -3 -10×10 -3 cm 3 / g, average pore radius ≤5nm.

4. The use according to claim 3, wherein: The specific surface area of ​​the metal organic framework material is 80-400m 2 / g, the total pore volume is 2×10 -3 -5×10 -3 cm 3 / g, and the average pore radius is 0.2-1nm.

5. A method for improving the selectivity of dimethyl terephthalate in a terephthalic acid esterification reaction, characterized in that: The method comprises: contacting terephthalic acid with alcohol in the presence of a catalyst; the catalyst is the metal organic framework material described in the application described in any one of claims 1 to 4.

6. The method according to claim 5, wherein: The contact conditions include: temperature of 20-200°C; pressure of 0.1-1 MPa; time of 20-80 hours; weight space velocity of terephthalic acid of 1-5 h -1 ; And / or, the molar ratio of terephthalic acid to alcohol is 1:(1-100).

7. The method according to claim 6, wherein: The contact conditions include: temperature of 50-150°C; pressure of 0.2-0.5 MPa; time of 30-60 hours; weight space velocity of terephthalic acid of 2-3 h -1 ; And / or, the molar ratio of terephthalic acid to alcohol is 1:(2-10).

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