Pd / MIL-101 (Fe) catalyst, preparation method thereof and application of Pd / MIL-101 (Fe) catalyst in Suzuki-Miyaura cross-coupling reaction

Abstract

The invention discloses a Pd / MIL-101 (Fe) catalyst, a preparation method of the Pd / MIL-101 (Fe) catalyst and an application of the Pd / MIL-101 (Fe) catalyst in a Suzuki-Miyaura cross coupling reaction. The preparation method of the catalyst comprises the following steps: by taking terephthalic acid and ferric trichloride hexahydrate as raw materials, preparing a precursor MIL-101 (Fe) by adopting a solvothermal method, then loading Pd on MOF by adopting a sol-gel method, and reducing in a hydrogen atmosphere to prepare Pd / MIL-101 (Fe). The catalyst is used in cross-coupling reaction of phenylboronic acid and aryl halide to obtain high-yield target products. The catalyst disclosed by the invention is simple in preparation process, high in catalytic activity, mild in reaction condition, simple in catalyst separation and good in cycling stability, can be reused after water washing treatment, and still keeps relatively high catalytic activity after being used for multiple times.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a Pd / MIL-101(Fe) catalyst, its preparation method, and its application in the Suzuki-Miyaura cross-coupling reaction. Background Technology

[0002] The Suzuki coupling reaction is the most efficient synthetic method for biaryl compounds and is widely used in the synthesis of natural products and organic materials. Its industrial applications are also extensive, such as in drug synthesis where it is widely used to construct the core structure of drug molecules to improve selectivity, or in the synthesis of organic materials with specific functions, such as conductive polymers and optoelectronic device materials. However, commonly used homogeneous palladium catalysts generally suffer from problems such as precious metal loss, poor catalyst stability, and difficulty in recycling during the reaction process, making it difficult to industrialize homogeneous catalytic systems.

[0003] Chinese invention patent CN 119303633 A reports a method for catalyzing the Suzuki-Miyaura cross-coupling reaction using a Pd / UiO-66-NH2@RGO composite material, achieving a yield of 99% after 1 hour of reaction at 80°C. However, the preparation method of the reported Pd / UiO-66-NH2@RGO catalyst is complex, the reaction conditions are relatively harsh, and it is not the best choice for large-scale application from the perspectives of economic efficiency and environmental protection. Summary of the Invention

[0004] The purpose of this invention is to provide a Pd / MIL-101(Fe) catalyst and its preparation method, and to apply this catalyst to the Suzuki – Miyaura cross-coupling reaction. The Pd / MIL-101(Fe) catalyst prepared by this invention has advantages such as good catalytic activity and selectivity, good stability, high yield of the target product, and mild reaction conditions.

[0005] This invention uses MIL-101(Fe) as a catalyst precursor, employs a sol-gel method to support Pd, and then reduces it under a hydrogen atmosphere to obtain a Pd / MIL-101(Fe) catalyst. Specifically, terephthalic acid and Fe salt are used as raw materials, and the precursor MIL-101(Fe) is prepared by a solvothermal method. Then, Pd is supported on a MOF using a sol-gel method, and Pd / MIL-101(Fe) is prepared by reduction under a hydrogen atmosphere. This catalyst was used in the cross-coupling reaction of phenylboronic acid and haloaromatic hydrocarbons, yielding high yields of the target product. The catalyst preparation process of this invention is simple, exhibits high catalytic activity, mild reaction conditions, easy catalyst separation, and good cycle stability. It can be reused after water washing and maintains high catalytic activity even after multiple uses.

[0006] The objective of this invention can be achieved through the following technical solutions: The preparation method of Pd / MIL-101(Fe) catalyst includes the following steps: (1) Dissolve terephthalic acid and Fe salt in a solvent and carry out a solvothermal reaction at 80~150℃ for 12~48 h. After cooling, centrifuge and wash, and then dry the washed solid under vacuum at 80~100℃ for 6~18 h to obtain catalyst precursor MIL-101(Fe). (2) Add a certain amount of protective agent to methanol, dissolve Pd salt in methanol, stir for 0.5~3h, add a certain amount of reducing agent to the solution, continue stirring for 1~5 min, add the precursor MIL-101(Fe) prepared in step (1) to the solution, and stir for 12~48h. (3) The MOF obtained in step (2) was reduced under a hydrogen atmosphere to prepare the Pd / MIL-101(Fe) catalyst.

[0007] Further, in step (1), the Fe salt is ferric nitrate or ferric chloride. The molar ratio of Fe salt to terephthalic acid is 1:0.5~3.

[0008] Further, in step (1), the solvent is N,N-dimethylformamide.

[0009] Furthermore, in step (2), the Pd salt is palladium nitrate or palladium chloride; the content of metallic Pd in ​​the catalyst is 0.5%~5%.

[0010] Further, in step (2), the protective agent is polyvinylpyrrolidone. The molar ratio of Pd salt to protective agent is 1:1~20.

[0011] Further, in step (2), the reducing agent is sodium borohydride. The molar ratio of Pd salt to reducing agent is 1:1~10.

[0012] Furthermore, in step (2), the mass of MIL-101(Fe) added is 40~400mg.

[0013] Furthermore, in step (3), the reduction treatment temperature is 200℃, the time is 1~3h, and the heating rate is 1~5℃ / min.

[0014] The Pd / MIL-101(Fe) catalyst obtained by the above preparation method has a regular octahedral morphology with a size of about 1 μm.

[0015] The synthetic route for the above-mentioned Pd / MIL-101(Fe) catalyst participating in the Suzuki – Miyaura cross-coupling reaction is as follows:

[0016] This invention also provides the application of the above-mentioned Pd / MIL-101(Fe) catalyst in the Suzuki – Miyaura cross-coupling reaction. Specifically, it includes the following steps: Benzylboronic acid, haloaromatic hydrocarbons, anhydrous ethanol, water, potassium carbonate and Pd / MIL-101(Fe) catalyst were added sequentially to the reactor. The mixture was stirred and heated to 30~60℃, and reacted at a constant temperature for 0.5~6 h. After cooling to room temperature, the catalyst was separated from the reaction system by centrifugation.

[0017] Furthermore, the molar ratio of the haloaromatic hydrocarbon to phenylboronic acid is 1:0.5~3; the molar ratio of the haloaromatic hydrocarbon to potassium carbonate is 1:1~5; and the mass ratio of the Pd / MIL-101(Fe) catalyst to the haloaromatic hydrocarbon is 1:10~40.

[0018] Furthermore, the halogenated aromatic hydrocarbon is one of iodobenzene, bromobenzene, p-bromotoluene, p-iodotoluene, p-bromophenol, 4-iodoanisole, and 4-bromoanisole.

[0019] Compared with the prior art, the technical effects of the present invention are as follows: (1) The Pd / MIL-101(Fe) catalyst of the present invention has high catalytic activity, good selectivity, mild reaction conditions, and low reaction temperature. It exhibits excellent performance in the Suzuki-Miyaura cross-coupling reaction, with high product yield. The whole process is in line with the concepts of economic benefits and green environmental protection.

[0020] (2) The preparation method of the Pd / MIL-101(Fe) catalyst provided by the present invention is simple and has good stability. It can be directly separated from the reaction system by centrifugation and can be reused after washing and drying. It still maintains good reaction activity after multiple uses, effectively solving the problems of existing catalysts being difficult to separate, recover and reuse. Attached Figure Description

[0021] Figure 1 This is the powder X-ray diffraction pattern of the Pd / MIL-101(Fe) catalyst.

[0022] Figure 2 Scanning electron microscope image of 0.5wt% Pd / MIL-101(Fe) catalyst.

[0023] Figure 3 Transmission electron microscopy image of 0.5wt% Pd / MIL-101(Fe) catalyst.

[0024] Figure 4 Scanning electron microscope image of 2wt% Pd / MIL-101(Fe) catalyst.

[0025] Figure 5 Transmission electron microscopy image of 2wt% Pd / MIL-101(Fe) catalyst.

[0026] Figure 6 Scanning electron microscope image of 5wt% Pd / MIL-101(Fe) catalyst.

[0027] Figure 7 Transmission electron microscopy image of 5wt% Pd / MIL-101(Fe) catalyst. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1 Preparation of 0.5wt% Pd / MIL-101(Fe) catalyst: Ferric chloride hexahydrate (2.5 mmol) and terephthalic acid (1.25 mmol) were dissolved in 15 mL of N,N-dimethylformamide and stirred at room temperature for 5 min. The mixture was then transferred to a hydrothermal reactor and maintained at 110 °C for 24 h. After natural cooling, the precipitate was collected by centrifugation and washed three times each with N,N-dimethylformamide and ethanol, respectively. The precipitate was then dried under vacuum at 80 °C for 12 h to obtain a brick-red powder, MIL-101(Fe). Polyvinylpyrrolidone (0.19 mmol) was dissolved in 20 mL of methanol and stirred for a few minutes. Palladium nitrate dihydrate (0.019 mmol) was added, and stirring continued for 1 h. Sodium borohydride (0.095 mmol) was added to the solution, and after stirring for a few minutes to form a stable colloidal solution, MIL-101(Fe) (400 mg) was added. Stirring continued for 24 h. The precipitate was collected by centrifugation, washed three times with methanol, and dried under vacuum at 80 °C for 12 h. The catalyst was reduced to 200℃ for 2 hours under a hydrogen atmosphere at a heating rate of 2.5℃ / min to obtain a 0.5wt% Pd / MIL-101(Fe) catalyst.

[0030] Figure 1 This is the X-ray diffraction (XRD) pattern of the 0.5 wt% Pd / MIL-101(Fe) catalyst obtained in this embodiment. No characteristic diffraction peaks of Pd nanoparticles were observed because the Pd nanoparticles are uniformly dispersed and have a relatively low content.

[0031] Figure 2 This is a scanning electron microscope (SEM) image of the 0.5 wt% Pd / MIL-101(Fe) catalyst obtained in this embodiment. The image shows that the material has a regular octahedral morphology, approximately 1 μm in size, and a rough surface with obvious pores.

[0032] Figure 3 This is a transmission electron microscope (TEM) image of the 0.5wt% Pd / MIL-101(Fe) catalyst obtained in this embodiment. The image shows that the material has a regular octahedral morphology, approximately 1 μm in size, with a rough outer surface and obvious internal pores.

[0033] Example 2 Preparation of 2wt% Pd / MIL-101(Fe) catalyst: Ferric chloride hexahydrate (2.5 mmol) and terephthalic acid (1.25 mmol) were dissolved in 15 mL of N,N-dimethylformamide and stirred at room temperature for 5 min. The mixture was then transferred to a hydrothermal reactor and maintained at 110 °C for 24 h. After natural cooling, the precipitate was collected by centrifugation and washed three times each with N,N-dimethylformamide and ethanol, respectively. The precipitate was then dried under vacuum at 80 °C for 12 h to obtain a brick-red powder, MIL-101(Fe). Polyvinylpyrrolidone (0.19 mmol) was dissolved in 20 mL of methanol and stirred for a few minutes. Palladium nitrate dihydrate (0.019 mmol) was then added, and stirring continued for 1 h. Sodium borohydride (0.095 mmol) was added to the solution, and after stirring for a few minutes to form a stable colloidal solution, MIL-101(Fe) (100 mg) was added. Stirring continued for 24 h. The precipitate was collected by centrifugation, washed three times with methanol, and dried under vacuum at 80 °C for 12 h. The catalyst was reduced to 200℃ for 2h under a hydrogen atmosphere at a heating rate of 2.5℃ / min to obtain a 2wt% Pd / MIL-101(Fe) catalyst.

[0034] Figure 1 This is the X-ray diffraction (XRD) pattern of the 2wt% Pd / MIL-101(Fe) catalyst obtained in this embodiment. No characteristic diffraction peaks of Pd nanoparticles were observed because the Pd nanoparticles are uniformly dispersed and have a relatively low content.

[0035] Figure 4 This is a scanning electron microscope (SEM) image of the 2wt% Pd / MIL-101(Fe) catalyst obtained in this embodiment. The image shows that the material has a regular octahedral morphology, approximately 1 μm in size, and a rough surface with obvious pores.

[0036] Figure 5 This is a transmission electron microscope (TEM) image of the 2wt% Pd / MIL-101(Fe) catalyst obtained in this embodiment. The image shows that the material has a regular octahedral morphology, approximately 1 μm in size, with a rough outer surface and obvious internal pores.

[0037] Example 3 Preparation of 5wt% Pd / MIL-101(Fe) catalyst: Ferric chloride hexahydrate (2.5 mmol) and terephthalic acid (1.25 mmol) were dissolved in 15 mL of N,N-dimethylformamide and stirred at room temperature for 5 min. The mixture was then transferred to a hydrothermal reactor and maintained at 110 °C for 24 h. After natural cooling, the precipitate was collected by centrifugation and washed three times each with N,N-dimethylformamide and ethanol, respectively. The precipitate was then dried under vacuum at 80 °C for 12 h to obtain a brick-red powder, MIL-101(Fe). Polyvinylpyrrolidone (0.19 mmol) was dissolved in 20 mL of methanol and stirred for a few minutes. Palladium nitrate dihydrate (0.019 mmol) was then added, and stirring continued for 1 h. Sodium borohydride (0.095 mmol) was added to the solution, and after stirring for a few minutes to form a stable colloidal solution, MIL-101(Fe) (40 mg) was added. Stirring continued for 24 h. The precipitate was collected by centrifugation, washed three times with methanol, and dried under vacuum at 80 °C for 12 h. The catalyst was reduced to 200℃ for 2 hours under a hydrogen atmosphere at a heating rate of 2.5℃ / min to obtain a 5wt% Pd / MIL-101(Fe) catalyst.

[0038] Figure 1 This is the X-ray diffraction (XRD) pattern of the 5wt% Pd / MIL-101(Fe) catalyst obtained in this example. No characteristic diffraction peaks of Pd nanoparticles were observed because the Pd nanoparticles are uniformly dispersed and have a relatively low content.

[0039] Figure 6 This is a scanning electron microscope (SEM) image of the 5wt% Pd / MIL-101(Fe) catalyst obtained in this embodiment. The image shows that the material has a regular octahedral morphology, approximately 1 μm in size, and a rough surface with obvious pores.

[0040] Figure 7 This is a transmission electron microscope (TEM) image of the 5wt% Pd / MIL-101(Fe) catalyst obtained in this embodiment. The image shows that the material has a regular octahedral morphology with a size of approximately 1 μm.

[0041] Example 4 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.056 mL of iodobenzene, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 40 °C. After reacting at this temperature for 0.5 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of biphenyl was 94.479%.

[0042] Example 5 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.052 mL of bromobenzene, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 40 °C. After reacting at this temperature for 2 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of biphenyl was 91.265%.

[0043] Example 6 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.052 mL of bromobenzene, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 60 °C. After reacting at a constant temperature for 1 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of biphenyl was 95.341%.

[0044] Example 7 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.109 g of p-iodotoluene, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 40 °C. After reacting at this temperature for 2 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of 4-methylbiphenyl was 92.692%.

[0045] Example 8 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.109 g of p-iodotoluene, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 60 °C. After reacting at this temperature for 1 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of 4-methylbiphenyl was 96.827%.

[0046] Example 9 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.061 mL of p-bromotoluene, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 40 °C. After reacting at this temperature for 6 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of 4-methylbiphenyl was 94.044%.

[0047] Example 10 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.061 mL of p-bromotoluene, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 60 °C. After reacting at a constant temperature for 1 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of 4-methylbiphenyl was 95.506%.

[0048] Example 11 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.086 g of p-bromophenol, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 40 °C. After reacting at this temperature for 6 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of p-phenylphenol was 87.054%.

[0049] Example 12 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.086 g of p-bromophenol, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 60 °C, and reacted at a constant temperature for 2 h. After cooling to room temperature, the reaction solution was analyzed by gas chromatography. The yield of p-phenylphenol was 91.299%.

[0050] Example 13 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.117 g of 4-iodoanisole, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 40 °C. After reacting at this temperature for 2 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of 4-methoxybiphenyl was 97.285%.

[0051] Example 14 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.117 g of 4-iodoanisole, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 60 °C. After reacting at a constant temperature for 1 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of 4-methoxybiphenyl was 97.413%.

[0052] Example 15 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.062 mL of 4-bromoanisole, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 40 °C. After reacting at this temperature for 6 h, the mixture was cooled to room temperature. The reaction solution was analyzed by gas chromatography, and the yield of 4-methoxybiphenyl was 87.127%.

[0053] Example 16 Application of Pd / MIL-101(Fe) catalyst in Suzuki – Miyaura cross-coupling reaction: 0.091 g of phenylboronic acid, 0.062 mL of 4-bromoanisole, 2 mL of anhydrous ethanol, 2 mL of water, 0.207 g of potassium carbonate, and 0.005 g of 2 wt% Pd / MIL-101(Fe) catalyst were added sequentially to the reaction vessel. The mixture was stirred and heated to 60 °C, and reacted at a constant temperature for 3 h. After cooling to room temperature, the reaction solution was analyzed by gas chromatography. The yield of 4-methoxybiphenyl was 99.291%.

[0054] It should be understood that the above detailed description of the technical solutions of the present invention with reference to optimized embodiments is illustrative and not restrictive. It should not be considered that the specific implementation of the present invention is limited to this. For those skilled in the art, any modifications to the technical solutions described in the embodiments or equivalent substitutions of some technical features without departing from the concept of the present invention should be considered as falling within the scope of patent protection defined by the claims submitted by the present invention.

Claims

1. A method for preparing a Pd / MIL-101(Fe) catalyst, characterized in that, Includes the following steps: (1) Terephthalic acid and Fe salt were dissolved in a solvent and subjected to a solvothermal reaction. After cooling, the mixture was centrifuged, washed, and dried to obtain the catalyst precursor MIL-101(Fe). (2) Add a protective agent to methanol, dissolve the Pd salt in methanol, stir, then add a reducing agent to the solution, add the MIL-101(Fe) prepared in step (1) to the solution, and continue stirring; (3) The MOF obtained in step (2) was reduced under a hydrogen atmosphere to prepare the Pd / MIL-101(Fe) catalyst.

2. The method for preparing a Pd / MIL-101(Fe) catalyst according to claim 1, characterized in that, In step (1), the Fe salt is ferric nitrate or ferric chloride; the molar ratio of Fe salt to terephthalic acid is 1:0.5~3.

3. The method for preparing a Pd / MIL-101(Fe) catalyst according to claim 1, characterized in that, The Pd salt is palladium nitrate or palladium chloride; the content of metallic Pd in ​​the catalyst is 0.5% to 5%.

4. The method for preparing a Pd / MIL-101(Fe) catalyst according to claim 1, characterized in that, In step (1), the solvent is N,N-dimethylformamide.

5. The method for preparing a Pd / MIL-101(Fe) catalyst according to claim 1, characterized in that, In step (2), the protective agent is polyvinylpyrrolidone, and the ratio of Pd salt to protective agent is 1:1~20; the reducing agent is sodium borohydride, and the ratio of Pd salt to reducing agent is 1:1~10; the mass of MIL-101(Fe) added in step (2) is 40~400mg.

6. The method for preparing a Pd / MIL-101(Fe) catalyst according to claim 1, characterized in that, In step (3), the reduction treatment is performed at a temperature of 200°C for 1 to 3 hours and at a heating rate of 1 to 5°C / min.

7. A Pd / MIL-101(Fe) catalyst obtained by the preparation method according to any one of claims 1-6.

8. The application of the Pd / MIL-101(Fe) catalyst according to claim 7 in the Suzuki – Miyaura cross-coupling reaction, characterized in that, Includes the following steps: Benzylboronic acid, haloaromatic hydrocarbons, anhydrous ethanol, water, potassium carbonate and Pd / MIL-101(Fe) catalyst were added sequentially to the reactor, stirred and heated to 30~60℃, reacted at a constant temperature for 0.5~6h, and then cooled to room temperature. The catalyst was separated from the reaction system by centrifugation.

9. The application of the Pd / MIL-101(Fe) catalyst according to claim 8 in the Suzuki – Miyaura cross-coupling reaction, characterized in that, The molar ratio of the haloaromatic hydrocarbon to phenylboronic acid is 1:0.5~3; the molar ratio of the haloaromatic hydrocarbon to potassium carbonate is 1:1~5; and the mass ratio of the Pd / MIL-101(Fe) catalyst to the haloaromatic hydrocarbon is 1:10~40.

10. The application of the Pd / MIL-101(Fe) catalyst according to claim 8 in the Suzuki – Miyaura cross-coupling reaction, characterized in that, The halogenated aromatic hydrocarbon is one of iodobenzene, bromobenzene, p-bromotoluene, p-iodotoluene, p-bromophenol, 4-iodoanisole, and 4-bromoanisole.

Images