Metallocene catalyst support and preparation method therefor and use thereof
By using MOF nanocasting technology to prepare silica supports, the morphology and pore structure problems of existing silica supports in metallocene catalysts were solved, achieving uniform distribution of the catalyst and improving the uniformity of polymerization products, thereby enhancing catalytic activity and product quality.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- PETROCHINA SHANGHAI ADVANCED MATERIALS RESEARCH INSTITUTE CO LTD
- Filing Date
- 2025-08-26
- Publication Date
- 2026-06-18
AI Technical Summary
Existing silica supports in metallocene catalysts suffer from problems such as difficulty in controlling particle morphology, non-uniform microporous structure, and insufficient catalytic activity, which affect the structural and performance uniformity of polyolefin products.
Metal-organic frameworks (MOFs) were used as nanocasting technology to prepare silica supports with uniform particle morphology and ordered pore structure. By controlling the ratio of silicon source to hydrolysis inhibitor and calcination temperature, the morphology and size of the support were precisely controlled, ensuring the uniform distribution of metallocene catalyst and co-catalyst.
This method achieves efficient dispersion of metallocene catalyst supports, improves catalytic activity and the uniformity of polymerization products, and ensures the structural uniformity and excellent performance of the polymerization products.
Smart Images
Figure CN2025117053_18062026_PF_FP_ABST
Abstract
Description
A metallocene catalyst support, its preparation method and application
[0001] This application claims priority to Chinese Patent Application No. CN 202411833543.1, filed on December 13, 2024, entitled "A metallocene catalyst support and its preparation method and application", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to the field of metallocene catalyst supports, specifically to a metallocene catalyst support, its preparation method, and its application. Background Technology
[0003] In the 1980s, the emergence and rise of metallocene catalysts triggered another revolution in the polyolefin industry, following the Ziegler-Natta catalyst. Metallocene catalysts consist of transition metals or rare earth metals with at least one cyclopentadienyl ligand or its derivative, possessing uniform active sites, thus their polymer products typically have a narrow molecular weight distribution. Furthermore, the chemical structure of metallocene catalysts is easily tunable, allowing us to design catalyst structures to obtain polymer products with specific properties, such as controlling molecular weight, chain structure, and comonomer content. Metallocene catalysts have developed rapidly in the polyolefin field in recent decades, enabling the preparation of various high-performance polymers in industrial plants, such as low-density linear polyethylene, isotactic polypropylene, polyolefin elastomers, EPDM rubber, and syndiotactic polystyrene. Metallocene catalysts were initially developed in homogeneous form, achieving extremely high activity through their combination with co-catalysts. However, homogeneous metallocene catalysts also have significant drawbacks, such as difficulty in controlling polymer particle morphology, severe reactor sticking, low polymer bulk density, easy deactivation of active centers, and excessive co-catalyst dosage. To address the aforementioned issues and better adapt to existing industrial olefin polymerization facilities, it is necessary to support metallocene catalysts. Metallocene support involves loading metallocene catalysts onto particulate supports using physical or chemical methods. While loading typically reduces catalyst activity, it yields polyolefin powders with regular morphology and high apparent density.
[0004] Inorganic supports suitable for metallocene loading mainly include amorphous SiO2, Al2O3, magnesium chloride complexes, ZrO2, zeolites, and composite supports. Organic supports mainly include polystyrene, polyethylene, and other polymer particles. Silica possesses high specific surface area, suitable pore volume and size, good flowability and mechanical strength, and is inexpensive, making it suitable for industrial production equipment and currently the most widely used metallocene support material in industry. However, silica supports also have certain drawbacks. First, they lack catalytic activity and have a simple structure, making it impossible to generate strong interactions with metallocene compounds or co-catalysts to enhance catalytic activity. Second, commercially available silica supports are typically spherical, with poor particle size uniformity and difficult morphology control, making it impossible to adjust the catalyst's morphology and size according to product requirements. Furthermore, from a nanoscale microstructure perspective, the pore structure of silica supports has poor uniformity, leading to insufficient uniformity in the microscopic distribution of metallocene compounds and co-catalysts, thus affecting the uniformity of the final product structure.
[0005] Several studies have addressed the shortcomings of existing silica-based support materials. Patent CN102020729A discloses a method for coating a silica support with an alumina activator. Metallocene catalyst compositions prepared based on this type of Si / Al composite support exhibit significantly improved activity. Furthermore, adjusting the composition and amount of the coating material can regulate the molecular weight and distribution of the final polymer product. Patent CN107459592A discloses a method for preparing a manganese chloride-modified silica support and its supported metallocene catalyst. When used for olefin polymerization, it significantly improves the catalytic activity while maintaining the molecular weight distribution and bulk density of the polymer obtained with the original metallocene catalyst (without manganese chloride). However, the modified silica supports described above use large amounts of modifying components, have disordered distribution, and low atom utilization. The addition of these modifying components also leads to a decrease in the specific surface area of the initial silica support. Moreover, although these modification methods improve catalyst activity by introducing additional guest components, they do not effectively control the pore structure and morphology of the support. Therefore, there is an urgent need to develop more efficient methods for preparing supports in order to achieve controllable preparation of the structure and morphology of metallocene catalyst supports, thereby enabling precise regulation of the structure and performance of polyolefin products. Summary of the Invention
[0006] This application provides a method for preparing a metallocene catalyst support. This method can easily prepare a variety of silica supports with different structures and compositions by controlling MOFs, achieving precise control of the support morphology and size. The preparation method is simple and easy to operate, and is convenient for industrial-scale preparation.
[0007] This application also provides a metallocene catalyst support with uniform particle morphology and ordered pore structure, which can ensure the uniformity of the microscopic distribution of the metallocene catalyst and the co-catalyst, thereby ensuring better uniformity of the polymerization product.
[0008] This application also provides a supported catalyst, in which the metallocene catalyst and the co-catalyst are well distributed on the support and can better ensure the uniformity of the polymerization product.
[0009] This application also provides a method for catalytic olefin polymerization, and the polyolefin products prepared by this method have good structural uniformity.
[0010] This application provides a method for preparing a metallocene catalyst support, comprising the following steps: mixing a silicon source, a hydrolysis inhibitor, and water uniformly, then immersing the mixture in a metal-organic framework material, controlling the temperature not to exceed 35°C for immersion treatment for 18-30 hours, removing the immersed metal-organic framework material, washing and drying it, and then calcining it in an air atmosphere at 400-550°C to obtain the metallocene catalyst support; wherein the silicon source is tetramethoxysilane or tetraethoxysilane.
[0011] In the preparation method of the metallocene catalyst support described above, the volume ratio of silicon source to hydrolysis inhibitor is (2-8):1.
[0012] In the preparation method of the metallocene catalyst support described above, the ratio of metal-organic framework material to silicon source is 100 mg: (0.5-1 mL).
[0013] In the preparation method of the metallocene catalyst support described above, the volume ratio of silicon source to water is (6-30):1.
[0014] In the preparation method of the metallocene catalyst support described above, the volume ratio of silicon source to hydrolysis inhibitor is 4-8:1.
[0015] The metallocene catalyst support prepared by the above method involves calcination at 450-550℃ for 0.5-1.5 hours.
[0016] The preparation method of the metallocene catalyst support described above uses an alcohol-based hydrolysis inhibitor.
[0017] The metal-organic framework material prepared by the above-described method for metallocene catalyst support is any one of UiO-66, UiO-67, hcp UiO-66, hcp UiO-67, MOF-74, MOF-808, MOF-333, MOF-519, ZIF-8, ZIF-90, ZIF-67, MIL-53, MIL-68, MIL-88B, MIL-96, MIL-100, MIL-101, MIL-110, MIL-140A, CAU-1, CAU-3, CAU-10, CAU-16, DUT-4, DUT-5, NU-2000, and PCN-333.
[0018] In the preparation method of the metallocene catalyst support described above, the hydrolysis inhibitor is one or more of methanol, ethanol, and butanol.
[0019] The metallocene catalyst support prepared by the above-described method uses metal-organic framework materials such as MIL-100-Al, MIL-100-Fe, MIL-96-Al, MIL-110-Al, and UiO-66-Zr.
[0020] This application also provides a metallocene catalyst support, which is prepared by the above method.
[0021] This application also provides a supported catalyst, including a metallocene catalyst and a co-catalyst supported on the aforementioned metallocene catalyst support.
[0022] The supported catalyst described above is obtained by reacting a support, a co-catalyst methylaluminoxane, and a metallocene catalyst rac-Et(Ind)2ZrCl2 in toluene solvent at 40±5℃ for 2-4 hours, separating the solid and drying it.
[0023] In the above-described supported catalyst, the mass ratio of the support, the co-catalyst methylaluminoxane, and the metallocene catalyst rac-Et(Ind)2ZrCl2 in the reaction solution is (1-3):1:(0.05-0.15).
[0024] This application also provides a method for catalytic polymerization of olefins, which includes at least the use of the above-described supported catalyst for catalysis.
[0025] The above-described method for catalytic olefin polymerization, wherein the olefin is propylene, is reacted at 70±5℃ for 0.5-1.5h under the action of hydrogen, triethylaluminum and a supported catalyst to obtain polypropylene product.
[0026] The method for preparing the metallocene catalyst support provided in this application is based on the nanocasting technology of metal-organic framework materials to prepare a highly dispersed metal oxide and silica composite material. Benefiting from the ordered pore structure and uniform chemical composition of MOFs, the novel silica support obtained by the above method replicates the particle morphology and pore structure of MOFs, exhibiting uniform particle morphology and ordered pore structure. Simultaneously, it allows the original metal components in MOFs to be transformed in situ into highly dispersed metal oxide clusters embedded in the silica framework, which is more conducive to catalyst dispersion and thus better ensures the uniformity of the polymerization product. Attached Figure Description
[0027] Figure 1 is a schematic diagram of the preparation process of the metallocene catalyst support described in this application;
[0028] Figure 2 is a scanning electron microscope image of the metallocene catalyst support in Example 4 of this application;
[0029] Figure 3 shows the pore size distribution of the metallocene catalyst support in Example 4 of this application;
[0030] Figure 4 is a scanning electron microscope image of the metallocene catalyst support in Example 11 of this application;
[0031] Figure 5 is a scanning electron microscope image of the metallocene catalyst support in Example 12 of this application;
[0032] Figure 6 is a scanning electron microscope image of the metallocene catalyst support in Example 14 of this application. Detailed Implementation
[0033] To facilitate understanding of this application, it will be described in more detail below. However, it should be understood that this application can be implemented in many different forms and is not limited to the embodiments or examples described herein. Rather, these embodiments or examples are provided to provide a more thorough and complete understanding of the disclosure of this application.
[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments or examples only and is not intended to be limiting of this application.
[0035] A method for preparing a metallocene catalyst support includes the following steps: mixing a silicon source, a hydrolysis inhibitor, and water evenly, then immersing the mixture in a metal-organic framework material, controlling the temperature not to exceed 35°C for immersion treatment for 18-30 hours, removing the immersed metal-organic framework material, washing and drying it, and then calcining it in an air atmosphere at 400-550°C to obtain the metallocene catalyst support; wherein the silicon source is tetramethoxysilane or tetraethoxysilane.
[0036] To address the shortcomings of traditional metallocene catalyst supports, such as difficulty in controlling particle morphology and poor microscopic pore order, this application provides a method for preparing highly dispersed metal oxide and silica composite materials based on metal-organic framework (MOF) nanocasting technology. Benefiting from the ordered pore structure and uniform chemical composition of MOFs, the novel silica support obtained using this method replicates the particle morphology and pore structure of MOFs, exhibiting uniform particle morphology and ordered pore structure. Furthermore, the original metal components in the MOFs are transformed in situ into highly dispersed metal oxide clusters embedded in the silica framework, which is more conducive to the uniform dispersion of the catalyst and better ensures the homogeneity of the polymerization product. By controlling MOFs, various silica supports with different structures and compositions can be prepared relatively easily, achieving precise control over the morphology and size of the support.
[0037] In this application, the volume ratio of silicon source to hydrolysis inhibitor is typically controlled at (2-8):1. Further research revealed that when the volume ratio of silicon source to hydrolysis inhibitor is low (below 4:1), the supported catalyst prepared from the resulting support exhibits a more significant advantage in regulating product uniformity. When the volume ratio of silicon source to hydrolysis inhibitor is controlled at 4-8:1, the supported catalyst prepared from the resulting support not only has an advantage in regulating product uniformity but also significantly improves its catalytic activity. This may be because at this ratio, the hydrolysis rate of the silicon source is moderate, ensuring that the silicon source is fully impregnated into the pores of the MOFs before complete hydrolysis. This results in better particle morphology and pore structure order of the calcined support, more uniform catalyst distribution, and thus better performance of the supported catalyst.
[0038] During the impregnation process, to ensure that the silicon source can be fully impregnated into the pores of MOFs, the ratio of metal-organic framework material to silicon source is usually controlled at 100 mg:(0.5-1 mL). There are no special restrictions on the volume ratio of silicon source to water in the impregnation solution, which is usually controlled at 6-30:1.
[0039] During the impregnation process, to facilitate operation, the temperature is typically controlled to be no higher than 35°C, and the impregnation time is 18-30 hours. More specifically, controlling the impregnation temperature at 25±5°C and the impregnation time at 22-26 hours simplifies the operation. In some specific embodiments, the temperature is controlled at 25°C, and the impregnation treatment is carried out for 24 hours.
[0040] During calcination, when the calcination temperature is too high (above 550℃), metal oxide clusters in MOF materials will agglomerate. This leads to a reduction in the number of usable metal sites in the support and a decrease in the uniformity of their distribution. Consequently, the number of sites that can interact with the metallocene catalyst in the final supported catalyst is reduced, and the uniformity of active sites is also decreased. Therefore, the polymerization activity is reduced, and the molecular weight distribution of the polymerization product is also poor. Therefore, in this application, the calcination temperature needs to be controlled at 400-550℃, and the calcination time is usually controlled at 0.5-1.5h. Studies have found that the performance is better when the calcination temperature is 450-550℃ and the calcination time is 0.5-1.5h. For example, in some specific embodiments, the calcination temperature is 500℃ and the calcination treatment is 1h.
[0041] The addition of a hydrolysis inhibitor can control the rate of silicon source hydrolysis, thereby making the impregnation process between the silicon source and MOF materials more complete. In this application, alcohols can be used as hydrolysis inhibitors because alcohols can react with partially hydrolyzed silicon sources to form alkoxysilanes, thus effectively inhibiting hydrolysis. For example, in some specific embodiments, the hydrolysis inhibitor is one or more of methanol, ethanol, and butanol.
[0042] The morphology and composition of the metal-organic framework also affect the performance of the final prepared carrier. In this application, the metal-organic framework material can be selected from any one of UiO-66, UiO-67, hcp UiO-66, hcp UiO-67, MOF-74, MOF-808, MOF-333, MOF-519, ZIF-8, ZIF-90, ZIF-67, MIL-53, MIL-68, MIL-88B, MIL-96, MIL-100, MIL-101, MIL-110, MIL-140A, CAU-1, CAU-3, CAU-10, CAU-16, DUT-4, DUT-5, NU-2000, and PCN-333. Considering structural stability and preparation cost, metal-organic framework materials are typically selected from any one of the following: UiO-66-Zr, hcp UiO-66-Zr, MIL-53-Al, MIL-96-Al, MIL-100-Al, MIL-100-Fe, MIL-101-Al, MIL-110-Al, ZIF-8-Zn, and MIL-140A-Zr.
[0043] However, the study found that when the metal-organic framework is selected from MIL-100-Al, MIL-100-Fe, MIL-96-Al, MIL-110-Al, and UiO-66-Zr, the performance of the support is better, and the final supported catalyst has better catalytic activity and uniformity of catalytic products.
[0044] This application also provides a metallocene catalyst support, which is prepared by the above method.
[0045] This application also provides a supported catalyst, comprising a metallocene catalyst and a co-catalyst supported on the aforementioned metallocene catalyst support. Because the support of this supported catalyst has a uniform particle morphology and an ordered pore structure, the metallocene catalyst and co-catalyst can be uniformly distributed, thereby effectively ensuring the uniformity of the catalytic product.
[0046] In some specific embodiments, the above-mentioned supported catalyst is obtained by reacting a support, a co-catalyst methylaluminoxane, and a metallocene catalyst rac-Et(Ind)2ZrCl2 in toluene solvent at 40±5℃ for 2-4 h, separating the solid and drying it. The mass ratio of the support, co-catalyst methylaluminoxane, and metallocene catalyst rac-Et(Ind)2ZrCl2 in the reaction solution is (1-3):1:(0.05-0.15), for example, a mass ratio of 2:1:0.1.
[0047] This application also provides a method for catalytic polymerization of olefins, which includes at least the use of the above-described supported catalyst for catalytic polymerization. The polymerization product prepared by this method has good uniformity, a narrow molecular weight distribution, and the method (or the supported catalyst used) exhibits excellent hydrogen regulation sensitivity.
[0048] In some specific embodiments, when the olefin is propylene, the propylene is reacted at 70±5℃ for 0.5-1.5h in the presence of hydrogen, triethylaluminum and a supported catalyst to obtain polypropylene product.
[0049] In some specific embodiments, the concentration of hydrogen is 0-300 ppm, the amount of propylene is 1.5 kg, the amount of triethylaluminum is 2 mL, and the amount of supported catalyst is 100 mg.
[0050] The preparation method of the metallocene catalyst support of this application will be described in detail below with reference to specific embodiments.
[0051] Example 1
[0052] S1. Measure out 6 mL of tetramethoxysilane, 3 mL of methanol and 1 mL of H2O, add them to a glass bottle and sonicate for five minutes to disperse them evenly.
[0053] S2. Weigh 0.6g of MIL-100-Al and add it to the mixed solution obtained in S1. Sonicate again for five minutes to ensure the mixed solution fully submerges the MOF sample. Seal the glass bottle and let it stand at 25°C for 24 hours to ensure that the SiO2 precursor fully enters the MOF channels. Then, centrifuge the solid sample and wash it with methanol to remove excess methoxysilane. Dry the methanol-washed sample at 60°C.
[0054] S3. Place the solid sample obtained in S2 in a magnetic boat and put it into a tube furnace. Heat the furnace to 500°C at a heating rate of 2°C / min under air atmosphere and hold for 1 hour. After cooling to room temperature, remove the powder, which is the final carrier material.
[0055] Metallocene loading test: 2g of the support material obtained in S3 was dispersed in 15mL of toluene, and 10mL of methylaluminoxane (MAO) toluene solution (0.1g / mL) and 100mg of rac-Et(Ind)2ZrCl2 were added. The mixture was stirred at 40℃ for 3h. After the reaction was completed, the solid was separated by sedimentation and washed three times with toluene solution. Finally, the solid was dried to obtain the final supported catalyst.
[0056] Propylene polymerization experiment: The 5L polymerization reactor was purged with dry nitrogen at least five times. Hydrogen (160ppm), propylene (1.5Kg), triethylaluminum impurity remover (2mL), and supported metallocene catalyst (100mg) were added to the reactor. The temperature was then raised to 70℃ and reacted for 1 hour. After the apparatus was cooled to room temperature, the product was discharged and dried to obtain polypropylene. The calculated activity was 3540gPP / gCat, and the molecular weight distribution of the product was 2.6.
[0057] Example 2
[0058] The method of Example 1 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the amounts of tetramethoxysilane, methanol, and water used in the support preparation process were 6 mL, 3 mL, and 0.5 mL, respectively. The final polymerization activity of the catalyst was 5688 gPP / gCat, and the molecular weight distribution of the product was 2.5.
[0059] Example 3
[0060] The method of Example 1 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the amounts of tetramethoxysilane, methanol, and water used in the support preparation process were 6 mL, 3 mL, and 0.2 mL, respectively. The final polymerization activity of the catalyst was 4739 gPP / gCat, and the molecular weight distribution of the product was 2.7.
[0061] Example 4
[0062] The method of Example 1 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the amounts of tetramethoxysilane, methanol, and water used in the support preparation process were 6 mL, 1.5 mL, and 0.5 mL, respectively. The final catalyst polymerization activity reached a maximum of 13400 gPP / gCat, and the molecular weight distribution of the product was 3.0. Figure 2 is a scanning electron microscope image of the metallocene catalyst support obtained in this example, and Figure 3 shows the pore size distribution determined by nitrogen adsorption-desorption. As can be seen from the above results, the obtained metallocene catalyst support has a uniform particle morphology and an ordered pore structure.
[0063] Example 5
[0064] The method of Example 1 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the amounts of tetramethoxysilane, methanol, and water used in the support preparation process were 6 mL, 0.75 mL, and 0.5 mL, respectively. The final polymerization activity of the catalyst was 11050 gPP / gCat, and the molecular weight distribution of the product was 2.8.
[0065] Example 6
[0066] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the amounts of tetramethoxysilane, methanol, and water used in the support preparation process were 6 mL, 1.5 mL, and 0.3 mL, respectively. The final polymerization activity of the catalyst was 12200 gPP / gCat, and the molecular weight distribution of the product was 3.1.
[0067] Example 7
[0068] The method of Example 5 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the amounts of tetramethoxysilane, methanol, and water used in the support preparation process were 6 mL, 0.75 mL, and 0.2 mL, respectively. The final polymerization activity of the catalyst was 9970 gPP / gCat, and the molecular weight distribution of the product was 2.9.
[0069] Example 8
[0070] The method of Example 4 was used for carrier preparation, metallocene loading, and propylene polymerization, except that the silicon source was tetraethoxysilane, the polymerization activity of the final catalyst was 6640 gPP / gCat, and the molecular weight distribution of the product was 3.2.
[0071] Example 9
[0072] The method of Example 4 was used for carrier preparation, metallocene loading, and propylene polymerization, except that the hydrolysis inhibitor was butanol, the final catalyst polymerization activity was 9810 gPP / gCat, and the molecular weight distribution of the product was 2.8.
[0073] Example 10
[0074] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the MOF precursor used was MIL-100-Fe. The final catalyst polymerization activity was 5963 gPP / gCat, and the molecular weight distribution of the product was 2.6.
[0075] Example 11
[0076] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the MOF precursor used was MIL-96-Al. The final catalyst polymerization activity was 8165 gPP / gCat, and the molecular weight distribution of the product was 2.7. Figure 4 is a scanning electron microscope image of the metallocene catalyst support obtained in this example.
[0077] Example 12
[0078] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the MOF precursor used was MIL-53-Al. The final catalyst polymerization activity was 3550 gPP / gCat, and the molecular weight distribution of the product was 2.3. Figure 5 is a scanning electron microscope image of the metallocene catalyst support obtained in this example.
[0079] Example 13
[0080] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the MOF precursor used was MIL-110-Al. The final catalyst polymerization activity was 7277 gPP / gCat, and the molecular weight distribution of the product was 2.9.
[0081] Example 14
[0082] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that UiO-66-Zr was used as the MOF precursor. The final catalyst polymerization activity was 7534 gPP / gCat, and the molecular weight distribution of the product was 2.7. Figure 6 is a scanning electron microscope image of the metallocene catalyst support obtained in this example.
[0083] Example 15
[0084] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the MOF precursor used was hcp UiO-66-Zr. The final catalyst polymerization activity was 5066 gPP / gCat, and the molecular weight distribution of the product was 2.5.
[0085] Example 16
[0086] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the MOF precursor used was MIL-140A-Zr. The final catalyst polymerization activity was 4709 gPP / gCat, and the molecular weight distribution of the product was 3.0.
[0087] Example 17
[0088] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization. The difference was that the MOF precursor was ZIF-8-Zn. The final catalyst polymerization activity was 5241 gPP / gCat, and the molecular weight distribution of the product was 3.3.
[0089] Example 18
[0090] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization, except that the calcination temperature of the support was 400°C, the polymerization activity of the final catalyst was 12053 gPP / gCat, and the molecular weight distribution of the product was 3.2.
[0091] Example 19
[0092] The method of Example 4 was used for carrier preparation, metallocene loading, and propylene polymerization, except that hydrogen was not introduced during the polymerization process. The final polymerization activity of the catalyst was 3580 gPP / gCat, and the molecular weight distribution of the product was 2.4.
[0093] Example 20
[0094] The method of Example 4 was used for carrier preparation, metallocene loading, and propylene polymerization, except that the hydrogen concentration during the polymerization process was 200 ppm, the final catalyst polymerization activity was 9357 gPP / gCat, and the molecular weight distribution of the product was 2.6.
[0095] Example 21
[0096] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization. The hydrogen concentration was 300 ppm in different polymerization processes. The final polymerization activity of the catalyst was 7660 gPP / gCat, and the molecular weight distribution of the product was 2.3.
[0097] Comparative Example 1
[0098] The method of Example 4 was used for metallocene-supported polymerization and propylene polymerization. The difference was that the MOF support was not nanocast but directly used as a catalyst support. The final polymerization activity of the catalyst was 4338 gPP / gCat and the molecular weight distribution of the product was 3.3.
[0099] Comparative Example 2
[0100] The method of Example 4 was used for metallocene-supported polymerization and propylene polymerization. The difference was that the MOF support MIL-100-Al was used as a catalyst support after being calcined at 500°C without impregnation treatment. The final polymerization activity of the catalyst was 2360 gPP / gCat, and the molecular weight distribution of the product was 3.4.
[0101] Comparative Example 3
[0102] The method of Example 4 was used for metallocene-supported polymerization and propylene polymerization, except that the commercial silica support SYLOPOL 2212D was used. The final catalyst polymerization activity was 2708 gPP / gCat, and the molecular weight distribution of the product was 3.5.
[0103] Comparative Example 4
[0104] The method of Example 4 was used for metallocene-supported polymerization and propylene polymerization, except that the mixed solution in step S1 did not contain the hydrolysis inhibitor methanol (i.e., it was impregnated with an aqueous solution of tetramethoxysilane). The final polymerization activity of the catalyst was 4320 gPP / gCat, and the molecular weight distribution of the product was 3.3.
[0105] Comparative Example 5
[0106] The method of Example 4 was used for metallocene-supported polymerization and propylene polymerization, except that the MOF was directly impregnated in tetramethoxysilane and calcined. The final polymerization activity of the catalyst was 5520 gPP / gCat, and the molecular weight distribution of the product was 4.0.
[0107] Comparative Example 6
[0108] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization, except that the calcination temperature of the support was 600°C, the polymerization activity of the final catalyst was 11560 gPP / gCat, and the molecular weight distribution of the product was 3.5.
[0109] Comparative Example 7
[0110] The method of Example 4 was used for support preparation, metallocene loading, and propylene polymerization, except that the calcination temperature of the support was 800°C, the final catalyst polymerization activity was 7033 gPP / gCat, and the molecular weight distribution of the product was 3.8. The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.
[0111] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
A method for preparing a metallocene catalyst support, wherein, Includes the following steps: The silicon source, hydrolysis inhibitor, and water are mixed evenly, and then the mixture is used to immerse the metal-organic framework material. The immersion treatment is carried out at a temperature not exceeding 35°C for 18-30 hours. The immersed metal-organic framework material is then removed, washed, dried, and calcined in air at 400-550°C to obtain the metallocene catalyst support. The silicon source is tetramethoxysilane or tetraethoxysilane. The method for preparing the metallocene catalyst support according to claim 1, wherein, The volume ratio of silicon source to hydrolysis inhibitor is (2-8):
1. The method for preparing the metallocene catalyst support according to claim 1, wherein, The ratio of metal-organic framework material to silicon source is 100 mg: (0.5-1 mL). The method for preparing the metallocene catalyst support according to claim 1, wherein, The volume ratio of silicon source to water is (6-30):
1. The method for preparing a metallocene catalyst support according to any one of claims 1-4, wherein, The calcination conditions are: 450-550℃, calcination for 0.5-1.5h. The method for preparing a metallocene catalyst support according to any one of claims 1-5, wherein, The hydrolysis inhibitor is an alcohol-based hydrolysis inhibitor. The method for preparing a metallocene catalyst support according to any one of claims 1-6, wherein, The metal-organic framework material is any one of UiO-66, UiO-67, hcp UiO-66, hcp UiO-67, MOF-74, MOF-808, MOF-333, MOF-519, ZIF-8, ZIF-90, ZIF-67, MIL-53, MIL-68, MIL-88B, MIL-96, MIL-100, MIL-101, MIL-110, MIL-140A, CAU-1, CAU-3, CAU-10, CAU-16, DUT-4, DUT-5, NU-2000, and PCN-333. The method for preparing the metallocene catalyst support according to claim 6, wherein, The hydrolysis inhibitor is one or more of methanol, ethanol, and butanol. The method for preparing the metallocene catalyst support according to claim 7, wherein, The metal-organic framework materials are MIL-100-Al, MIL-100-Fe, MIL-96-Al, MIL-110-Al, and UiO-66-Zr. A metallocene catalyst support, wherein, It is prepared by the preparation method according to any one of claims 1-9. A supported catalyst, wherein, This includes a metallocene catalyst and a co-catalyst supported on the metallocene catalyst support of claim 10. The supported catalyst according to claim 11, wherein, The supported catalyst was obtained by reacting a support, a co-catalyst methylaluminoxane, and a metallocene catalyst rac-Et(Ind)2ZrCl2 in toluene solvent at 40±5℃ for 2-4 h, followed by separation of the solid and drying. According to the supported catalyst of claim 12, the mass ratio of the support, the co-catalyst methylaluminoxane, and the metallocene catalyst rac-Et(Ind)2ZrCl2 in the reaction solution is (1-3):1:(0.05-0.15). A method for catalytic olefin polymerization, wherein, At least includes catalysis using the supported catalyst as described in any one of claims 11-13. The method for catalytic olefin polymerization according to claim 14, wherein, The olefin is propylene. The propylene is reacted at 70±5℃ for 0.5-1.5h in the presence of hydrogen, triethylaluminum and a supported catalyst to obtain polypropylene product.