A MOFs catalyst, its preparation method and application
By synthesizing stable aluminum-based MOFs via a hydrothermal method and loading noble metals via an impregnation reduction method, the problem of easy detachment of noble metal nanoparticles was solved, resulting in a highly active and reusable noble metal catalyst suitable for the hydrogenation reaction of unsaturated rubber.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING UNIV OF CHEM TECH
- Filing Date
- 2026-03-17
- Publication Date
- 2026-06-09
Smart Images
Figure CN122164501A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of catalysts, and more particularly to a MOF catalyst, its preparation method, and its application. Background Technology
[0002] Rubber is widely used in the automotive, construction and machinery fields due to its good mechanical properties and processing properties. Some rubbers have poor aging resistance due to the presence of unsaturated double bonds in their chain segments. Hydrogenation can effectively improve their mechanical properties and aging resistance, such as nitrile rubber, styrene-butadiene rubber and isoprene rubber.
[0003] Heterogeneous catalysts have attracted widespread attention due to their excellent hydrogenation selectivity and recyclability. Heterogeneous catalysts typically involve loading noble metals onto porous supports, such as porous carbon, carbon nanotubes, and silica. MOFs (Metal-Organic Facility-Formed Materials) are porous materials with regular channel structures formed by the coordination of metals and organic ligands. CN110756225A discloses a method for loading noble metal rhodium nanoparticles onto the surface of MOFs via impregnation chemical reduction. However, the MOF structure is easily destroyed during chemical reduction, and nanoparticles may detach during the reaction. In the preparation of heterogeneous catalysts, loading noble metal nanoparticles onto the surface via impregnation reduction makes it difficult to form strong interactions with traditional porous supports. Loading noble metal nanoparticles inside the channels limits their catalytic activity against macromolecules. Currently, there is an urgent need in this field for a catalyst that forms strong interactions between noble metals and the support surface, exhibits excellent hydrogenation activity and reusability for unsaturated rubber, and allows for effective cost reduction under mild hydrogenation conditions. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention provides a MOF catalyst, its preparation method, and its applications. The method of this invention can prepare stable aluminum-based MOFs and obtain a catalyst with strong interaction between noble metals and aluminum-based MOFs. This MOF catalyst exhibits stable properties, excellent performance, good morphology, high activity, and good selectivity for double bonds. Furthermore, this MOF catalyst can be recovered by centrifugation and reused multiple times.
[0005] In a first aspect, this invention provides a method for preparing a MOF catalyst with strong interaction between a noble metal and an aluminum-based MOF, comprising: using an aluminum-based MOF as a support, loading a noble metal via an impregnation reduction method, followed by gas-phase reduction; wherein the aluminum-based MOF is synthesized via a hydrothermal method using a precursor and an organic ligand as raw materials, the metal precursor being an aluminum salt or a hydrated aluminum salt, and the organic ligand being selected from one or more of squaric acid, terephthalic acid, 2-fluoroterephthalic acid, biphenyl dicarboxylic acid, bipyridine, bipyridine dicarboxylic acid, trimesic acid, tetraphenylacetic acid, and hexaphenylacetic acid; the noble metal including a Pd salt. This invention finds that by using a precursor and organic ligand as raw materials to synthesize MOFs via a hydrothermal method and then impregnating and reducing the MOF catalyst, a heterogeneous catalyst with strong interaction between a noble metal and an aluminum-based MOF can be achieved, and the noble metal is highly dispersed in the MOF; furthermore, the catalyst can be repeatedly recycled and reused, exhibiting good hydrogenation activity and reusability.
[0006] Preferably, the metal precursor is selected from one or more of AlCl3, Al(NO3)3, Al(SO4)3, AlCl3·H2O, AlCl3·6H2O, Al(NO3)3·9H2O, and Al(SO4)3·18H2O, with Al(NO3)2·9H2O or AlCl3·6H2O being more preferred. Preferably, the organic ligand is biphenyl dicarboxylic acid. This is beneficial for obtaining a support and MOF catalyst with better performance.
[0007] Further preferably, the molar ratio of the metal precursor to the organic ligand is (1~3):1, for example 1.2:1, 1.5:1, 1.7:1, 1.8:1, 2:1, 2.5:1, 2.8:1, etc., preferably (1~2):1. This invention also found that using biphenyl dicarboxylic acid as the organic ligand and controlling the molar ratio of the precursor to the organic ligand within the range of (1~2):1 yields even better results.
[0008] Preferably, the solvent used in the hydrothermal method is selected from one or more of water, ethanol, DMF, cyclohexane, DEF, methanol, DMAC, and DMSO, with DMF being the most preferred.
[0009] Further preferably, the temperature of the hydrothermal method is 110~150℃, more preferably 120~130℃, and the time is 12~48h, more preferably 12~24h.
[0010] According to the present invention, the impregnation method used in the embodiments of the present invention is the over-impregnation method.
[0011] As a preferred technical solution, before the hydrothermal method, the metal precursor, organic ligand, and solvent are mixed evenly; preferably, the mixture is subjected to ultrasonication for 10-60 min and magnetic stirring for 10-30 min. More preferably, the metal precursor, organic ligand, and solvent are mixed evenly and reacted at 120°C for 24 h.
[0012] Preferably, the Pd salt is selected from one or more of palladium chloride, potassium chloride palladiumite, sodium chloride palladiumite, palladium nitrate, palladium acetate, and palladium chloride diacetonitrile, with palladium acetate being the most preferred; the solvent for the impregnation method is selected from water, acetone, dichloromethane, ethanol, methanol, or DMF, with water or dichloromethane being the most preferred.
[0013] Preferably, the mass ratio of the Pd salt to the support is (0.01~0.2):1, more preferably (0.05~0.1):1. The catalyst effect is better at the preferred ratio.
[0014] Preferably, the gas-phase reduction is carried out in a hydrogen-argon mixed atmosphere, wherein the volume content of hydrogen in the hydrogen-argon mixed atmosphere is preferably 5% to 10%, the reduction temperature is preferably 150 to 300°C, and the reduction time is preferably 1 to 6 hours.
[0015] As a preferred technical solution, the hydrogen content in the hydrogen-argon mixture is 5%, and the reduction time is 2-6 hours.
[0016] As a preferred technical solution, the preparation method includes: loading at room temperature for 12 hours; and reduction at 200°C for 4 hours in 5% hydrogen / argon gas.
[0017] This invention prepares stable aluminum-based MOFs materials via a hydrothermal method, and obtains a catalyst with highly dispersed noble metals and strong interaction with aluminum-based MOFs by slow reduction in hydrogen via an impregnation reduction method, which is of great significance for catalytic hydrogenation.
[0018] In a second aspect, the present invention provides a MOFs catalyst, wherein the MOFs catalyst is selected from one or more of MIL-101(Al), MIL-101-NH2(Al), MIL-53(Al), MIL-53-NH2(CrM), DUT-5(Al), MIL-100(Al), and MIL-96(Al), and is preferably prepared by the above-mentioned MOFs catalyst preparation method.
[0019] Thirdly, the present invention provides the application of the above-mentioned MOF catalyst in the hydrogenation of rubber.
[0020] Preferably, the MOF catalyst is used for the preparation of unsaturated rubber by hydrogenation, and is preferably used for the preparation of hydrogenated nitrile rubber by hydrogenation of nitrile rubber, the preparation of hydrogenated styrene-butadiene rubber by hydrogenation of styrene-butadiene rubber, or the preparation of hydrogenated hydroxyl-terminated liquid nitrile rubber by hydrogenation of hydroxyl-terminated liquid hydrogenated nitrile rubber.
[0021] Preferably, the reaction includes: using rubber and the catalyst as raw materials to carry out a catalytic hydrogenation reaction; preferably, the amount of the MOF catalyst is 10-100% of the mass of the rubber, more preferably 50-100%; the temperature of the catalytic hydrogenation reaction is 30-150℃, more preferably 30-120℃, and the time is 1-24 h, more preferably 2-8 h; the pressure of the catalytic hydrogenation reaction is preferably 1-10 MPa; the rubber is preferably added in the form of a nitrile rubber solution, and the solvent of the rubber is selected from one or more of chlorobenzene, xylene, acetone, chloroform, dichloromethane, cyclohexanone, tetrahydrofuran, and cyclohexane, preferably tetrahydrofuran or acetone.
[0022] The beneficial effects of the present invention are at least as follows: the present invention obtains stable aluminum-based MOFs by hydrothermal method and obtains a catalyst with strong interaction between noble metal and aluminum-based MOFs by impregnation reduction method. Furthermore, the MOF catalyst has stable properties, excellent performance, good morphology, high activity, and good selectivity for double bonds. In addition, the MOF catalyst can be recovered by centrifugation and reused multiple times. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0024] Figure 1 This is a SEM image of the MOFs catalyst of Example 1 of the present invention.
[0025] Figure 2 For the hydrogenation NBR using the MOFs catalyst of Example 6 of this invention 1 HNMR image. Detailed Implementation
[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0027] The endpoints and any values of the ranges disclosed in this invention 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 the various ranges, the endpoint values of the various ranges and individual point values, and 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 invention.
[0028] Unless otherwise specified, the techniques or conditions described in the embodiments of this invention shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Devices, instruments, reagents, etc., without specified manufacturers, are all conventional products that can be purchased through legitimate channels. All experimental reagents and raw materials involved are commercially available products, and all reagents are analytical grade products.
[0029] Example 1 This embodiment provides a MOF catalyst (DUT-5@Pd(1)), the preparation method of which includes the following steps: 15 mmol aluminum nitrate nonahydrate and 10 mmol biphenyl dicarboxylic acid were dissolved in DMF, sonicated for 30 min to dissolve completely, stirred for 30 min, reacted in a hydrothermal reactor at 120℃ for 12 h, cooled overnight, centrifuged to collect the precipitate, washed three times with solvent, and dried at 50℃ to obtain DUT-5.
[0030] A certain amount of DUT-5 was dispersed in deionized water, and 5% potassium palladium chloride by mass of MOFs was added. The mixture was stirred for 12 hours and then dried by centrifugation. The MOFs were then placed in a tube furnace at 200℃ for 4 hours in a mixture of 5% hydrogen and argon to obtain DUT-5@Pd(1).
[0031] The SEM image of the MOF catalyst in this embodiment is shown below. Figure 1 As shown.
[0032] Example 2 This embodiment provides a MOF catalyst (DUT-5@Pd (2)), the preparation method of which includes the following steps: 15 mmol aluminum nitrate nonahydrate and 10 mmol biphenyl dicarboxylic acid were dissolved in DMF, sonicated for 30 min to dissolve completely, stirred for 30 min, reacted in a hydrothermal reactor at 120℃ for 12 h, cooled overnight, centrifuged to collect the precipitate, washed three times with solvent, and dried at 50℃ to obtain DUT-5.
[0033] A certain amount of DUT-5 was dispersed in deionized water, and 10% of the mass of MOFs potassium chloride palladium was added. The mixture was stirred for 12 hours and then centrifuged and dried. The MOFs were then placed in a tube furnace at 200°C for 4 hours in a 5% hydrogen-argon mixture to obtain DUT-5@Pd(2).
[0034] Example 3 This embodiment provides a MOF catalyst (DUT-5@Pd (3)), the preparation method of which includes the following steps: 15 mmol aluminum nitrate nonahydrate and 10 mmol biphenyl dicarboxylic acid were dissolved in DMF, sonicated for 30 min to dissolve completely, stirred for 30 min, reacted in a hydrothermal reactor at 120℃ for 12 h, cooled overnight, centrifuged to collect the precipitate, washed three times with solvent, and dried at 50℃ to obtain DUT-5.
[0035] A certain amount of DUT-5 was dispersed in dichloromethane, and 5% palladium acetate (by mass of MOFs) was added. The mixture was stirred for 12 hours and then dried by centrifugation. The MOFs were then placed in a tube furnace at 200°C for 4 hours in a mixture of 5% hydrogen and argon to obtain DUT-5@Pd(3).
[0036] Example 4 This embodiment provides a MOF catalyst (DUT-5@Pd (4)), the preparation method of which includes the following steps: 15 mmol aluminum nitrate nonahydrate and 10 mmol biphenyl dicarboxylic acid were dissolved in DMF, sonicated for 30 min to dissolve completely, stirred for 30 min, and reacted in a hydrothermal reactor at 120 °C for 24 h. After cooling overnight, the precipitate was collected by centrifugation, washed three times with solvent, and dried at 50 °C to obtain DUT-5.
[0037] A certain amount of DUT-5 was dispersed in dichloromethane, and 5% palladium acetate (by mass of MOFs) was added. The mixture was stirred for 12 hours and then dried by centrifugation. The MOFs were then placed in a tube furnace at 200°C for 4 hours in a mixture of 5% hydrogen and argon to obtain DUT-5@Pd(4).
[0038] The MOF catalysts of Examples 1-4 were analyzed, and the results are shown in Table 1.
[0039] Table 1
[0040] Example 5 This embodiment utilizes the above-mentioned catalyst to hydrogenate nitrile rubber, and the specific operation is as follows: Nitrile rubber was dissolved in acetone solution with a mass fraction of 1% to obtain NBR solution; 7 g of NBR solution was placed in a 30 mL high-pressure hydrogenation reactor, and MOF catalyst with a catalyst dosage of 50% of the dry rubber mass was added. The reaction was carried out at 80 °C for 2 h at a pressure of 3 MPa and a rotation speed of 800 r / min. The hydrogenation degree results are shown in Table 2.
[0041] Table 2 Degree of hydrogenation of different MOFs
[0042] Example 6 In this embodiment, the above-mentioned DUT-5@Pd(3) catalyst is used to hydrogenate nitrile rubber. The specific operation is as follows: Nitrile butadiene rubber (NBR) was dissolved in acetone solution to obtain NBR solution (1% by mass). 7 g of the NBR solution was placed in a 30 mL high-pressure hydrogenation reactor, and MOF catalysts were added at amounts of 12.5%, 25%, 50%, and 100% of the dry rubber mass. The reactor was hydrogenated at 80 °C for 2 h at a pressure of 3 MPa and a rotation speed of 800 r / min. The hydrogenation results are shown in Table 3. Figure 2 .
[0043] Table 3. Effects of different MOF dosages on the degree of hydrogenation of nitrile rubber.
[0044] As shown in Table 3, the MOF catalyst of the present invention has high hydrogenation catalytic activity and double bond selectivity for nitrile rubber, with a hydrogenation degree of up to 99.8%.
[0045] Example 7 In this embodiment, the above-mentioned DUT-5@Pd(4) catalyst is used to hydrogenate nitrile rubber. The specific operation is as follows: Nitrile rubber was dissolved in acetone solution with a mass fraction of 1% to obtain NBR solution. 7 g of NBR solution was placed in a 30 mL high-pressure hydrogenation reactor, and MOF catalyst with a catalyst dosage of 50% of the dry rubber mass was added. The reaction was carried out at a pressure of 3 MPa and a rotation speed of 800 r / min at 30℃, 50℃, 80℃, and 120℃ for 6 h. The degree of hydrogenation is shown in Table 4.
[0046] Table 4 Degrees of NBR hydrogenation of MOF catalysts at different temperatures
[0047] As shown in Table 4, the MOF catalyst of the present invention has good activity for hydrogenation of nitrile rubber over a wide temperature range. The degree of hydrogenation can reach 97.8% after 2 hours of hydrogenation at 30°C, effectively reducing energy consumption.
[0048] Example 8 In this embodiment, hydrogenation of nitrile rubber is performed using DUT-5@Pd(3), and the specific operation is as follows: Nitrile rubber was dissolved in chlorobenzene, xylene, tetrahydrofuran, acetone and dichloromethane solutions, respectively, with a mass fraction of 1%, to obtain NBR solutions. 7 g of NBR solutions were taken into a 30 mL high-pressure hydrogenation reactor, and MOF catalyst with a catalyst dosage of 50% of the dry rubber mass was added. The reactor was hydrogenated at a pressure of 3 MPa, a rotation speed of 800 r / min and a temperature of 80 °C for 2 h. The degree of hydrogenation is shown in Table 5.
[0049] Table 5. Degree of hydrogenation of NBR in different solvents
[0050] As shown in Table 5, the MOF catalyst of the present invention has good applicability to different solvents, with the worst activity in chlorobenzene and the best activity of 94.1% in acetone.
[0051] Example 9 In this embodiment, hydrogenation of nitrile rubber is performed using DUT-5@Pd(4), and the specific operation is as follows: Nitrile rubber was dissolved in acetone solution with a mass fraction of 1% to obtain NBR solution. 7 g of NBR solution was placed in a 30 mL high-pressure hydrogenation reactor, and MOF catalyst with a catalyst dosage of 50% of the dry rubber mass was added. The reaction was carried out at a pressure of 3 MPa, a rotation speed of 800 r / min, and a temperature of 80 °C for 2 h. After the reaction was completed, the solution was recovered by centrifugation, washed with acetone and DMF, and the hydrogenation step was repeated. The degree of hydrogenation results are shown in Table 6.
[0052] Table 6. Degree of hydrogenation results of repeated hydrogenation of MOF catalysts.
[0053] As shown in Table 6, the degree of hydrogenation of nitrile rubber can reach 97.8% after 2 hours, indicating that the MOFs catalyst of the present invention has good activity for hydrogenation of nitrile rubber; after repeating three times, the degree of hydrogenation can reach 94.5%, indicating that the MOFs catalyst of the present invention has a good reusability effect.
[0054] Comparative Example 1 This comparative example provides a MOF catalyst (ZIF-8@Pd), the preparation method of which includes the following steps: 4 mmol of 2-methylimidazole and 1 mmol of zinc nitrate hydrate were dissolved in methanol, sonicated for 30 min to dissolve completely, stirred for 30 min, allowed to stand overnight, centrifuged to collect the precipitate, washed three times with solvent, and dried at 50°C to obtain ZIF-8.
[0055] A certain amount of ZIF-8 was dispersed in deionized water, and 5% (by weight) of potassium palladium chloride (MOFs) was added. The mixture was stirred for 12 hours and then centrifuged and dried. The MOFs were then placed in a tube furnace at 200°C for 4 hours in a mixture of 5% hydrogen and argon to obtain ZIF-8@Pd.
[0056] Comparative Example 2 This comparative example provides a MOF catalyst (UIO-66-NH2@Pd), the preparation method of which includes the following steps: 10 mmol of zirconium chloride and 10 mmol of 2-aminoterephthalic acid were dissolved in a mixed solvent of acetic acid and DMF, and sonicated for 30 min to dissolve completely. The mixture was then reacted in a hydrothermal reactor at 120 °C for 12 h, cooled overnight, and the precipitate was collected by centrifugation. The precipitate was washed three times with solvent and dried at 50 °C to obtain UIO-66-NH2.
[0057] A certain amount of UIO-66-NH2 was dispersed in deionized water, and 5% potassium chloride palladium chlorite (by mass of MOFs) was added. The mixture was stirred for 12 hours and then centrifuged and dried. The MOFs were then placed in a tube furnace at 200°C for 4 hours in a 5% hydrogen-argon mixture to obtain UIO-66-NH2@Pd.
[0058] Comparative Example 3 This comparative example provides a MOF catalyst (MIL-101-NH2@Pd), the preparation method of which includes the following steps: 10 mmol of chromium nitrate hydrate and 10 mmol of 2-aminoterephthalic acid were dissolved in an aqueous solution of sodium hydroxide and sonicated for 30 min to dissolve completely. The mixture was then reacted in a hydrothermal reactor at 150 °C for 12 h, cooled overnight, and the precipitate was collected by centrifugation. The precipitate was washed three times with solvent and dried at 50 °C to obtain MIL-101-NH2.
[0059] A certain amount of MIL-101-NH2 was dispersed in deionized water, and 5% potassium chloride palladiumate (by mass of MOFs) was added. The mixture was stirred for 12 hours and then centrifuged and dried. The MOFs were then placed in a tube furnace at 200°C for 4 hours in a 5% hydrogen-argon mixture to obtain MIL-101-NH2@Pd.
[0060] Comparative Example 4 This comparative example provides a MOF catalyst (ZIF-67@Pd), the preparation method of which includes the following steps: 4 mmol of 2-methylimidazole and 1 mmol of cobalt nitrate hydrate were dissolved in methanol, sonicated for 30 min to dissolve completely, stirred for 30 min, allowed to stand overnight, centrifuged to collect the precipitate, washed three times with solvent, and dried at 50°C to obtain ZIF-67.
[0061] A certain amount of ZIF-67 was dispersed in deionized water, and 5% (by weight) of potassium palladium chloride (MOFs) was added. The mixture was stirred for 12 hours and then centrifuged and dried. The MOFs were then placed in a tube furnace at 200°C for 4 hours in a mixture of 5% hydrogen and argon to obtain ZIF-67@Pd.
[0062] Comparative Example 5 This comparative example utilizes the aforementioned comparative catalyst to hydrogenate nitrile rubber, and the specific operation is as follows: Nitrile rubber was dissolved in acetone solution with a mass fraction of 1% to obtain NBR solution; 7 g of NBR solution was placed in a 30 mL high-pressure hydrogenation reactor, and MOF catalyst with a catalyst dosage of 50% of the dry rubber mass was added. The reaction was carried out at 80 °C for 2 h at a pressure of 3 MPa and a rotation speed of 800 r / min; the degree of hydrogenation results are shown in Table 7.
[0063] Table 7 Degree of hydrogenation of different MOFs
[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for preparing a MOF catalyst, characterized in that, include: Using an aluminum-based MOF as a carrier, noble metals are loaded via an impregnation reduction method, followed by gas-phase reduction. The aluminum-based MOF is synthesized via a hydrothermal method using a precursor and organic ligand as raw materials. The metal precursor is an aluminum salt or a hydrated aluminum salt, and the organic ligand is selected from one or more of squaric acid, terephthalic acid, 2-fluoroterephthalic acid, biphenyl dicarboxylic acid, bipyridine, bipyridine dicarboxylic acid, pyromellitic tricarboxylic acid, pyromellitic tetracarboxylic acid, and pyromellitic hexacarboxylic acid. The noble metal includes Pd salts.
2. The method for preparing the MOF catalyst according to claim 1, characterized in that, The metal precursor is selected from one or more of AlCl3, Al(NO3)3, Al(SO4)3, AlCl3·H2O, AlCl3·6H2O, Al(NO3)3·9H2O, and Al(SO4)3·18H2O.
3. The method for preparing the MOF catalyst according to claim 2, characterized in that, The molar ratio of the metal precursor to the organic ligand is (1~3):
1.
4. The method for preparing the MOF catalyst according to any one of claims 1-3, characterized in that, The solvent used in the hydrothermal method is selected from one or more of water, ethanol, DMF, cyclohexane, DEF, methanol, DMAC, and DMSO.
5. The method for preparing the MOF catalyst according to claim 4, characterized in that, The hydrothermal method is performed at a temperature of 110~150℃ for a duration of 12~48h.
6. The method for preparing the MOF catalyst according to any one of claims 1-5, characterized in that, The Pd salt is selected from one or more of palladium chloride, potassium chloride palladiumite, sodium chloride palladiumite, palladium nitrate, palladium acetate, and palladium chloride diacetonitrile; the solvent for the impregnation method is selected from water, acetone, dichloromethane, ethanol, methanol, or DMF. And / or, the mass ratio of the Pd salt to the support is (0.01~0.2):1; And / or, the gas phase reduction is carried out in a hydrogen-argon mixed atmosphere.
7. A MOF catalyst, characterized in that, It is prepared by the method of any one of claims 1-6 for the preparation of MOF catalysts.
8. The application of the MOF catalyst according to claim 7 in the hydrogenation of rubber.
9. The application according to claim 8, characterized in that, The MOF catalyst is used for the preparation of unsaturated rubber by hydrogenation, preferably for the preparation of hydrogenated nitrile rubber by hydrogenation of nitrile rubber, the preparation of hydrogenated styrene-butadiene rubber by hydrogenation of styrene-butadiene rubber, or the preparation of hydrogenated hydroxyl-terminated liquid nitrile rubber by hydrogenation of hydroxyl-terminated liquid hydrogenated nitrile rubber.
10. The application according to claim 8 or 9, characterized in that, include: Using rubber and the catalyst as raw materials, a catalytic hydrogenation reaction is carried out; preferably, the amount of the MOF catalyst is 10-100% of the mass of the rubber; the temperature of the catalytic hydrogenation reaction is 30-150℃, and the time is 1-24 h; the pressure of the catalytic hydrogenation reaction is preferably 1-10 MPa; the rubber is preferably added in the form of a nitrile rubber solution, and the solvent of the rubber is selected from one or more of chlorobenzene, xylene, acetone, chloroform, dichloromethane, cyclohexanone, tetrahydrofuran, and cyclohexane.