An eo hydrogenolysis heterogeneous catalyst and a method for preparing the same

Abstract

The application discloses a kind of for preparing 3-hydroxy methyl propionate by ethylene oxide hydrogen esterification multiphase catalyst and its preparation method, the catalyst is composed of metal component and organic phosphorus nitrogen porous polymer, wherein metal component is one of cobalt and palladium, organic phosphorus nitrogen porous polymer is the porous organic polymer obtained by ternary copolymerization of organic phosphorus containing vinyl and phenyl, pyridine containing vinyl and p-methyl styrene.The organic phosphorus nitrogen porous polymer as carrier can form stable coordination bond with metal component, and play the role of reaction promoter in catalytic reaction.The multiphase catalyst product of the application has excellent selectivity, good repeatability, can effectively reduce the separation cost of catalyst and product in EO hydrogen esterification reaction, and has wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of heterogeneous catalysis technology, specifically relating to the preparation and application of an EO hydrogen esterification heterogeneous catalyst. Background Technology

[0002] Polypropylene terephthalate (PTT) is a promising new polyester polymer material developed after polyethylene terephthalate (PET) in the 1950s and polybutylene terephthalate (PBT) in the 1970s. The primary use of 1,3-propanediol is as a monomer in the polymerization of terephthalic acid to produce PTT. It is also a raw material for the production of antifreeze, antislip agents, plasticizers, cosmetics, and surfactants. Currently, there are three main processing methods for 1,3-propanediol: the ethylene oxide hydroformylation hydrogenation method industrialized by Shell in 1996; the acrolein hydration hydrogenation method developed by Degussa in 1995; and the microbial fermentation method represented by DuPont in the United States. These three methods do not differ significantly in terms of production capacity, but each has its own characteristics. The acrolein hydration hydrogenation process has mild conditions, relatively low technical difficulty, and a mature hydrogenation process with low equipment requirements. However, the raw material, acrolein, is highly toxic, flammable, and explosive, making it difficult to store and transport, and it is also costly. Microbial fermentation, characterized by "green chemistry," utilizes renewable resources, resulting in a clean production environment, mild reaction conditions, simple operation, and low pollution. However, it produces low product concentrations, making it difficult to improve production efficiency. Ethylene oxide is abundant and inexpensive, making the ethylene oxide process highly favored. However, the intermediate 3-hydroxypropanal in the ethylene oxide hydroformylation process is extremely unstable, requiring complex catalytic separation technology and a high-pressure reactor (greater than 10 MPa), resulting in high equipment requirements, significant overall technical difficulty, and high investment costs. In contrast, the ethylene oxide hydrogen esterification process produces 1,3-propanediol, generating methyl 3-hydroxypropionate, thus avoiding the formation of 3-hydroxypropanal, and has become a new research direction for the ethylene oxide process.

[0003] Patent US6191321 uses a Co2(CO)8 / 1,10-phenanthroline catalyst, reacting at 90°C and 7.6 MPa for 18 hours, achieving only 11% conversion of ethylene oxide and a 74% selectivity for methyl 3-hydroxypropionate. Patent US6521801 uses a cobalt salt catalyst coordinated with nitrogen-containing heterocyclic compounds, achieving 94% conversion of ethylene oxide and a 78% selectivity for methyl 3-hydroxypropionate at 75°C and 6 MPa. Patent CN101020635A uses a cobalt carbonyl catalyst, achieving 80-98% conversion of ethylene oxide at 50-100°C and 3-7 MPa, but only 80% selectivity for methyl 3-hydroxypropionate. Patents CN107349962 and CN107417527, using Co2(CO)8 / imidazole as a catalyst, achieved an ethylene oxide conversion of 87% and a methyl 3-hydroxypropionate yield of 83% after a reaction at 75°C and 2 MPa for 5 h. Patents CN 107456995 and CN107459451, using ionic liquids and catalysts composed of cuprous halides or cobalt chloride, achieved an ethylene oxide conversion of 71%–89% and a methyl 3-hydroxypropionate selectivity of 83%–86% after a reaction at 60–75°C and 5–6 MPa.

[0004] In ethylene oxide (EO) hydrogen esterification, most current processes employ a cobalt carbonyl homogeneous catalytic system, which exhibits high catalytic activity and selectivity for the target product under mild reaction conditions. However, the difficulty in separating the cobalt homogeneous catalyst from the reactants hinders the large-scale application of homogeneous catalytic systems in EO hydrogen esterification. With advancements in homogeneous immobilization technology, researchers have begun investigating techniques for heterogeneous catalysts in EO hydrogen esterification.

[0005] Patent CN1125712A uses 5%-40% low-concentration olefins with 2-6 carbon atoms as raw materials to support a carbonyl Rh-P homogeneous catalyst on polymer microspheres or alumina supports. Patent CN102281948A reports a polymer-supported transition metal catalyst complex and its usage method, preparing a polymer-supported rhodium catalyst with a narrow molecular weight distribution. However, the catalyst preparation, catalytic reaction, and catalyst separation processes are all complex. Catalyst preparation requires first controlling the synthesis of soluble polymers such as functional monomers and styrene, then introducing ligands, and finally loading the Rh catalyst. Compressed gas needs to be added during the catalytic reaction. The catalyst is separated from the reaction mixture by nanofiltration, but the reaction results are not ideal. Patent CN106431926B reports the use of carbonyl cobalt supported in 4-vinylpyridine monomer block copolymers with molecular weights ranging from 60,000 to 160,000,000, copolymerized with 4-vinylpyridine and other comonomers such as styrene, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and ethyl vinylbenzene. However, it suffers from low trihydroxypropionate conversion and does not provide data on catalyst cycling stability. Patent CN113713862B describes the use of divalent cobalt salts supported on vinyl organophosphorus ligands, which are then solvothermally polymerized to form a cobalt-based heterogeneous catalyst, which is applied to the EO formylation reaction. This patent also does not provide data on catalyst cycling stability. Therefore, developing stable heterogeneous supported catalytic systems has significant practical application implications. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a heterogeneous catalyst for EO hydrogen esterification reactions.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An EO hydrogen esterification heterogeneous catalyst, the catalyst being composed of a metal component and an organophosphorus nitrogen porous polymer; the metal component being one of cobalt and palladium, and the organophosphorus nitrogen porous polymer being a block-structured porous organic polymer obtained by solvent polymerization of organophosphorus containing vinyl and phenyl groups, pyridine containing vinyl groups, and p-methylstyrene.

[0009] Furthermore, the aforementioned metal components account for 0.1-20.0% of the total weight of the heterogeneous catalyst.

[0010] Furthermore, the specific surface area of ​​the above-mentioned organophosphorus nitrogen porous polymer is 600-1200 m². 2 / g, pore volume 0.1-5.0 cm³ 3 / g, with a pore size distribution of 0.1-200 nm.

[0011] A method for preparing an EO hydrogen esterification heterogeneous catalyst includes the following steps:

[0012] (1) Add solvent and free radical initiator to organophosphorus containing vinyl and phenyl, pyridine containing vinyl and p-methylstyrene, and stir at room temperature for 1-5 h to form a prepolymer solution;

[0013] (2) Pour the prepolymerization solution from step (1) into a hydrothermal reactor and perform hot melt polymerization at 100-150 °C for 2-25 h. After cooling to room temperature, filter, soak in anhydrous ethanol, wash, filter, and dry at 50 °C for 5 h to obtain the organophosphorus nitrogen porous polymer.

[0014] (3) Dissolve the precursor of the metal component in a solvent to obtain a solution containing the metal component, add the organophosphorus nitrogen porous polymer, stir at room temperature for 0.5-20 h, then heat to 50-80℃ and continue stirring for 0.5-20 h, cool to room temperature and filter, dry at 50℃ for 5 h to obtain the organophosphorus nitrogen porous polymer supported metal active component heterogeneous catalyst.

[0015] Further, the free radical initiator in step (1) is one of benzoyl peroxide and azobisisobutyronitrile; the ratio of the amount of the free radical initiator to the total weight of the organophosphine containing vinyl and phenyl, the pyridine containing vinyl and p-methylstyrene is 1:1000-1:10.

[0016] Further, the solvent in step (1) is one or more of benzene, toluene, tetrahydrofuran, methanol, ethanol, methyl acetate, and methyl tert-butyl ether.

[0017] Further, the precursors of the metal components cobalt and palladium in step (3) are one or more of Co(NO3)2, CoCl2, Co(OAc)2, Co(acac)2, Co(OH)2, PdCl2, Pd(NO3)2, H2PdCl4, and Pd(OAc)2; and the solvent is one or more of methanol, ethanol, methyl acetate, and methyl tert-butyl ether.

[0018] The present invention also provides an application of the above-mentioned heterogeneous catalyst in the EO hydrogen esterification reaction. The specific operation steps are as follows: under the conditions of the heterogeneous catalyst, ethylene oxide, carbon monoxide and methanol are subjected to hydrogen esterification reaction in a batch reactor. The reaction temperature is 30-100℃, the reaction pressure is 0.1-10.0 MPa, the reaction time is 3-25 h, the molar ratio of ethylene oxide and the loaded metal of the heterogeneous catalyst is 20-200:1, and the weight percentage of the metal component in the reaction system is 0.2 wt%-0.5 wt%.

[0019] This invention uses an organophosphorus monomer (organophosphorus containing vinyl and phenyl groups) as a comonomer. The lone pair of electrons from the phosphorus atom can act as an electron pair donor to form σ bonds with the metal, and the empty d orbitals can form π bonds with the metal, resulting in stable coordination bonds and improving catalyst stability, preventing metal loss during the reaction. Simultaneously, a nitrogen monomer (pyridine containing vinyl groups) is used as a comonomer, introducing the nitrogen structure into the reaction system. The nitrogen structure on the support coordinates with the metal under reaction conditions to form Lewis acidic sites, promoting ethylene oxide ring-opening and thus increasing the reaction rate. This also avoids the problem of difficult separation of nitrogen promoters such as imidazole and pyridine in the EO hydrogen esterification reaction of traditional homogeneous catalysts. Finally, p-methylstyrene is used as a polymerization coupling agent. By adding a suitable proportion of coupling agent, a porous polymer with a specific block structure is formed, adjusting the nitrogen and phosphorus structure distribution sites and promoting reaction activity and product selectivity. This invention involves ternary copolymerization of the promoter required for EO hydrogen esterification, the phosphine ligand of the stabilizing metal, and p-methylstyrene to obtain an organophosphine nitrogen porous polymer, which is then loaded with metal to obtain a heterogeneous catalyst. This improves the binding ability of the metal on the organic support and reduces the separation cost of the catalyst from the reactants and products.

[0020] The beneficial effects of this invention are as follows:

[0021] (1) Compared with existing homogeneous catalyst preparation technology, the use of novel heterogeneous catalysts reduces the separation cost of catalyst from reactants and products while ensuring the selectivity of catalyst products.

[0022] (2) Compared with existing heterogeneous catalysts, it has higher catalyst stability and can be reused after the reaction, making it suitable for industrial production. Attached Figure Description

[0023] Figure 1 : Schematic diagram of the structure of the organophosphorus nitrogen porous polymer prepared in Example 1.

[0024] Figure 2 Examples 1 and 6-8: EO conversion and 3-HPM selectivity in EO hydrogenation reaction.

[0025] Figure 3 Comparative Examples 3-6: EO conversion and 3-HPM selectivity in EO hydrogenation reaction. Detailed Implementation

[0026] To make the content of this invention easier to understand, the technical solution of this invention will be further described below with reference to specific embodiments, but this invention is not limited thereto.

[0027] Example 1

[0028] In a fume hood, 4.8 g of diphenyl(4-vinylphenyl)phosphine, 2.8 g of 4-vinylpyridine, and 2.6 g of p-methylstyrene were weighed and added to a 250 ml polymerization flask. 100 ml of tetrahydrofuran and 0.20 g of azobisisobutyronitrile (azobisisobutyronitrile) free radical initiator were added, and the mixture was stirred at room temperature for 2 h to form a prepolymer solution. The prepolymer solution was poured into a hydrothermal reactor and subjected to a hot melt polymerization reaction at 100 °C for 15 h. After the reaction was complete, the hydrothermal reactor was cooled to room temperature. The polymer in the reactor was filtered, soaked in anhydrous ethanol, washed, filtered again, and dried in a 50 °C oven for 5 h to obtain an organophosphorus nitrogen porous polymer (specific surface area 850 m²). 2 / g, pore volume 1.2 cm 3 / g, pore size distribution 0.5-100 nm).

[0029] 0.95 g of cobalt acetate was dissolved in 100 ml of methanol, and 3.0 g of the prepared organic nitrogen-phosphorus porous polymer was added. After stirring at room temperature for 2 h, the temperature was raised to 50-80 °C and stirring was continued for 10 h. After cooling to room temperature, the mixture was filtered. The solid obtained by filtration was placed in an oven at 50 °C and dried for 5 h to obtain a cobalt-supported heterogeneous catalyst of organic phosphorus-nitrogen porous polymer.

[0030] All the catalyst was transferred to a 200 ml reactor, which was then purged three times with nitrogen. Carbon monoxide, 0.15 mol ethylene oxide, and 100 ml methanol were added to bring the system pressure to 6 MPa. The reaction was carried out at 40 °C for 20 hours. After the reaction was completed, the reactor was cooled to 0 °C, and the pressure was slowly released to atmospheric pressure. The reactor was then purged three times with nitrogen, and samples were taken for analysis. The EO conversion rate and 3-HPM selectivity are shown in Table 1.

[0031] Example 2

[0032] In a fume hood, 4.8 g of diphenyl(4-vinylphenyl)phosphine, 2.8 g of 4-vinylpyridine, and 2.6 g of p-methylstyrene were weighed and added to a 250 ml polymerization flask. 100 ml of tetrahydrofuran and 0.30 g of benzoyl peroxide (a free radical initiator) were added, and the mixture was stirred at room temperature for 2 h to form a prepolymer solution. The prepolymer solution was poured into a hydrothermal reactor and subjected to hot melt polymerization at 100 °C for 15 h. After cooling to room temperature, the polymer in the reactor was filtered, soaked in anhydrous ethanol, washed, filtered again, and dried in a 50 °C oven for 5 h to obtain an organophosphorus nitrogen porous polymer (specific surface area 826 m²). 2 / g, pore volume 1.06cm 3 / g, pore size distribution 0.5-120 nm).

[0033] 0.95 g of cobalt acetate was dissolved in 100 ml of methanol, and 3.0 g of the prepared organic nitrogen-phosphorus porous polymer was added. After stirring at room temperature for 2 h, the temperature was raised to 50-80 °C and stirring was continued for 10 h. After cooling to room temperature, the mixture was filtered. The solid obtained by filtration was placed in an oven at 50 °C and dried for 5 h to obtain a cobalt-supported heterogeneous catalyst of organic phosphorus-nitrogen porous polymer.

[0034] The catalytic process conditions were the same as in Example 1, and the EO conversion and 3-HPM selectivity are shown in Table 1.

[0035] Example 3

[0036] In a fume hood, 5.8 g of tris(4-vinylphenyl)phosphine, 2.8 g of 4-vinylpyridine, and 2.6 g of p-methylstyrene were weighed and added to a 250 ml polymerization flask. 100 ml of tetrahydrofuran and 0.20 g of azobisisobutyronitrile (AIBN) free radical initiator were added, and the mixture was stirred at room temperature for 2 h to form a prepolymer solution. The prepolymer solution was poured into a hydrothermal reactor and subjected to hot melt polymerization at 100 °C for 15 h. After cooling to room temperature, the polymer in the reactor was filtered, soaked in anhydrous ethanol, washed, filtered again, and dried in a 50 °C oven for 5 h to obtain an organophosphorus nitrogen porous polymer (specific surface area 920 m²). 2 / g, pore volume 1.13 cm 3 / g, pore size distribution 0.5-100 nm).

[0037] 0.95 g of cobalt acetate was dissolved in 100 ml of methanol, and 3.0 g of the prepared organic nitrogen-phosphorus porous polymer was added. After stirring at room temperature for 2 h, the temperature was raised to 50-80 °C and stirring was continued for 10 h. After cooling to room temperature, the mixture was filtered. The solid obtained by filtration was placed in an oven at 50 °C and dried for 5 h to obtain a cobalt-supported heterogeneous catalyst of organic phosphorus-nitrogen porous polymer.

[0038] The catalytic process conditions were the same as in Example 1, and the EO conversion and 3-HPM selectivity are shown in Table 1.

[0039] Example 4

[0040] In a fume hood, 5.8 g of tris(4-vinylphenyl)phosphine, 2.8 g of 4-vinylpyridine, and 2.6 g of p-methylstyrene were weighed and added to a 250 ml polymerization flask. 100 ml of tetrahydrofuran and 0.20 g of azobisisobutyronitrile (AIBN) free radical initiator were added, and the mixture was stirred at room temperature for 2 h to form a prepolymerization solution. The prepolymerization solution was poured into a hydrothermal reactor and subjected to hot melt polymerization at 100 °C for 15 h. After cooling to room temperature, the polymer in the reactor was filtered, soaked in anhydrous ethanol, washed, filtered again, and dried in a 50 °C oven for 5 h to obtain a phosphine-nitrogen porous organic polymer (specific surface area 920 m²).2 / g, pore volume 1.13 cm 3 / g, pore size distribution 0.5-100 nm).

[0041] 0.50 g of cobalt hydroxide was dissolved in 100 ml of methanol, and 3.0 g of the prepared organic nitrogen-phosphorus porous polymer was added. After stirring at room temperature for 2 h, the temperature was raised to 50-80 °C and stirring was continued for 10 h. After cooling to room temperature, the mixture was filtered. The solid obtained by filtration was placed in an oven at 50 °C and dried for 5 h to obtain a cobalt-supported heterogeneous catalyst of organic phosphorus-nitrogen porous polymer.

[0042] The catalytic process conditions were the same as in Example 1, and the EO conversion and 3-HPM selectivity are shown in Table 1.

[0043] Example 5

[0044] In a fume hood, 4.8 g of diphenyl(4-vinylphenyl)phosphine, 2.6 g of p-methylstyrene, and 2.8 g of 4-vinylpyridine were weighed and added to a 250 ml polymerization flask. 100 ml of tetrahydrofuran and 0.20 g of the free radical initiator azobisisobutyronitrile were added, and the mixture was stirred at room temperature for 2 h to form a prepolymerization solution. The prepolymerization solution was poured into a hydrothermal reactor and subjected to hot melt polymerization at 50 °C for 15 h. After cooling to room temperature, the polymer in the reactor was filtered, soaked in anhydrous ethanol, washed, filtered again, and dried in a 50 °C oven for 5 h to obtain an organophosphine nitrogen porous polymer (specific surface area 650 m²). 2 / g, pore volume 0.89 cm³ 3 / g, pore size distribution 0.8-180 nm).

[0045] 0.95 g of cobalt acetate was dissolved in 100 ml of methanol, and 3.0 g of the prepared organic nitrogen-phosphorus porous polymer was added. After stirring at room temperature for 2 h, the temperature was raised to 50-80 °C and stirring was continued for 10 h. After cooling to room temperature, the mixture was filtered. The solid obtained by filtration was placed in an oven at 50 °C and dried for 5 h to obtain a cobalt-supported heterogeneous catalyst of organic phosphorus-nitrogen porous polymer.

[0046] The catalytic process conditions were the same as in Example 1, and the EO conversion and 3-HPM selectivity are shown in Table 1.

[0047] Example 6

[0048] The catalyst from the reaction in Example 1 was centrifuged and recovered, and then dissolved in 100 ml of methanol. The resulting catalyst solution was directly transferred to a 200 ml reactor, which was purged three times with nitrogen. Carbon monoxide and ethylene oxide were added to bring the system pressure to 6 MPa; the reaction was carried out at 40 °C for 20 h. After the reaction was completed, the reactor was cooled to 0 °C, and the pressure was slowly released to atmospheric pressure, followed by purging the reactor three times with nitrogen. Samples were taken for analysis, and the EO conversion rate and 3-HPM selectivity are shown in Table 1.

[0049] Example 7

[0050] The catalyst from the reaction in Example 6 was centrifuged and recovered, and then dissolved in 100 ml of methanol. The resulting catalyst was subjected to catalysis again under the same conditions as in Example 6. The EO conversion and 3-HPM selectivity are shown in Table 1.

[0051] Example 8

[0052] The catalyst from the reaction in Example 7 was centrifuged and recovered, and then dissolved in 100 ml of methanol. The resulting catalyst was subjected to catalysis again under the same conditions as in Example 6. The EO conversion and 3-HPM selectivity are shown in Table 1.

[0053] Comparative Example 1

[0054] In a fume hood, 10 g of diphenyl(4-vinylbenzene)phosphine was weighed and added to a 250 ml polymerization flask, along with 100 ml of tetrahydrofuran and 0.20 g of azobisisobutyronitrile (AIBN) as a free radical initiator. The mixture was stirred at room temperature for 2 h to form a prepolymer solution. The prepolymer solution was then poured into a hydrothermal reactor and subjected to a hot melt polymerization reaction at 100 °C for 15 h. After cooling to room temperature, the polymer in the reactor was filtered, soaked in anhydrous ethanol, washed, filtered again, and dried in a 50 °C oven for 5 h to obtain an organophosphine porous polymer (specific surface area 960 m²). 2 / g, pore volume 1.25 cm³ 3 / g, pore size distribution 0.2-100 nm).

[0055] 0.95 g of cobalt acetate was dissolved in 100 ml of methanol, and 3.0 g of the organic porous polymer prepared above was added. After stirring at room temperature for 2 h, the temperature was raised to 50-80 °C and stirring was continued for 10 h. After cooling to room temperature, the mixture was filtered. The solid obtained by filtration was placed in an oven at 50 °C and dried for 5 h to obtain a cobalt-supported heterogeneous catalyst of organophosphorus porous polymer.

[0056] The catalytic process conditions were the same as in Example 1, and the EO conversion and 3-HPM selectivity are shown in Table 1.

[0057] Comparative Example 2

[0058] In a fume hood, 6 g of diphenyl(4-vinylphenyl)phosphine and 3.5 g of 4-vinylpyridine were weighed and added to a 250 ml polymerization flask. 100 ml of tetrahydrofuran and 0.20 g of azobisisobutyronitrile (AIBN) free radical initiator were added, and the mixture was stirred at room temperature for 2 h to form a prepolymer solution. The prepolymer solution was poured into a hydrothermal reactor and subjected to a hot melt polymerization reaction at 100 °C for 15 h. After cooling to room temperature, the polymer in the reactor was filtered, soaked in anhydrous ethanol, washed, filtered again, and dried in a 50 °C oven for 5 h to obtain an organophosphine nitrogen porous polymer (specific surface area 830 m²). 2 / g, pore volume 1.16cm 3 / g, pore size distribution 0.5-200 nm).

[0059] 0.95 g of cobalt acetate was dissolved in 100 ml of methanol, and 3.0 g of the organic porous polymer prepared above was added. After stirring at room temperature for 2 h, the temperature was raised to 50-80 °C and stirring was continued for 10 h. After cooling to room temperature, the mixture was filtered. The solid obtained by filtration was placed in an oven at 50 °C and dried for 5 h to obtain a heterogeneous catalyst of cobalt supported on an organophosphorus nitrogen porous polymer.

[0060] The catalytic process conditions were the same as in Example 1, and the EO conversion and 3-HPM selectivity are shown in Table 1.

[0061] Comparative Example 3

[0062] Using alumina as the catalyst support, 0.95 g of cobalt acetate was dissolved in 3 ml of aqueous solution and impregnated onto 10 g of alumina support using an equal-volume impregnation method. The impregnated catalyst was dried at 120 °C and then calcined at 500 °C for 4 h. After calcination, the catalyst was placed in a tube furnace and reduced with hydrogen at 300 °C to obtain a cobalt-supported alumina catalyst (specific surface area 330 m²). 2 / g, pore volume 0.5 cm 3 / g, pore size distribution 0.4-500 nm).

[0063] The catalytic process conditions were the same as in Example 1, and the EO conversion and 3-HPM selectivity are shown in Table 1.

[0064] Comparative Example 4

[0065] The catalyst from the reaction in Comparative Example 3 was centrifuged and recovered, and then dissolved in 100 ml of methanol. The resulting catalyst was subjected to catalysis again under the same conditions as in Example 6. The EO conversion and 3-HPM selectivity are shown in Table 1.

[0066] Comparative Example 5

[0067] The catalyst from the reaction in Example 4 was centrifuged and recovered, and then dissolved in 100 ml of methanol. The resulting catalyst was subjected to catalysis again under the same conditions as in Example 6. The EO conversion and 3-HPM selectivity are shown in Table 1.

[0068] Comparative Example 6

[0069] The catalyst from the reaction in Example 5 was centrifuged and recovered, and then dissolved in 100 ml of methanol. The resulting catalyst was subjected to catalysis again under the same conditions as in Example 6. The EO conversion and 3-HPM selectivity are shown in Table 1.

[0070] Table 1. EO conversion rate and 3-HPM selectivity in the examples and comparative examples.

[0071]

[0072] As shown in Table 1, the organophosphorus nitrogen porous polymers of Examples 1-2, after being loaded with Co metal, all exhibited good 3-HPM selectivity in the EO hydroesterification reaction. Among them, the organophosphorus nitrogen porous polymer prepared with azobisisobutyronitrile initiator showed higher catalytic activity after being loaded with Co metal. In Example 3, replacing diphenyl(4-vinylphenyl)phosphine with p-tris(4-vinylphenyl)phosphine as the monomer to prepare the organophosphorus nitrogen porous polymer resulted in a porous polymer with a large specific surface area. After being loaded with Co metal, it also exhibited good 3-HPM selectivity and catalytic activity in the EO hydroesterification reaction. In Example 4, replacing the cobalt acetate metal salt with cobalt hydroxide also resulted in good 3-HPM selectivity and catalytic activity in the EO hydroesterification reaction. Compared with Example 1, Example 5 reduced the temperature of the hot solvent polymerization method, resulting in varying degrees of decrease in the 3-HPM selectivity and activity of the catalyst. In Examples 6-8, the catalyst after the reaction in Example 1 was recovered and reused. The EO hydroesterification catalyst activity decreased slightly, but the selectivity remained stable. Figure 2 ).

[0073] Comparisons 1-3 with Example 1 show that the catalysts obtained by using diphenyl(4-vinylbenzene)phosphine monomer alone, without adding the coupling agent p-methylstyrene to obtain a large-surface porous organic polymer, and using alumina as an organic support to support Co metal, all exhibit poor 3-HPM selectivity and catalyst activity in the EO hydrogen esterification reaction. In Comparisons 4-6, the catalyst from Comparative Example 3 was recovered and reused, and the EO hydrogen esterification catalyst activity and 3-HPM selectivity decreased significantly. Figure 3 ).

[0074] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. The application of a heterogeneous catalyst in the hydrogen esterification reaction of EO, characterized in that: The heterogeneous catalyst is composed of a metal component and an organophosphorus nitrogen porous polymer; the metal component is one of cobalt and palladium, and the organophosphorus nitrogen porous polymer is a block-structured porous organic polymer obtained by solvent polymerization of organophosphorus containing vinyl and phenyl groups, pyridine containing vinyl groups, and p-methylstyrene; the specific surface area of ​​the organophosphorus nitrogen porous polymer is 826-1200 m². 2 / g, pore volume 1.06-1.2 cm³ 3 / g, with a pore size distribution of 0.1-200 nm; under the conditions of the heterogeneous catalyst, ethylene oxide, carbon monoxide and methanol are subjected to hydrogen esterification reaction in a batch reactor at a reaction temperature of 30-100℃, a reaction pressure of 0.1-10.0 MPa and a reaction time of 3-25 h. The block structure of the organophosphorus nitrogen porous polymer is shown below: 。 2. The application according to claim 1, characterized in that: The metal component accounts for 0.1-20.0% of the total weight of the heterogeneous catalyst.

3. The application according to claim 1, characterized in that: The preparation method of heterogeneous catalysts includes the following steps: (1) Add solvent and free radical initiator to organophosphorus containing vinyl and phenyl, pyridine containing vinyl and p-methylstyrene, and stir at room temperature for 1-5 h to form a prepolymer solution; (2) Pour the prepolymerization solution from step (1) into a hydrothermal reactor and perform hot melt polymerization at 100-150 °C for 2-25 h. After cooling to room temperature, filter, soak in anhydrous ethanol, wash, filter, and dry at 50 °C for 5 h to obtain the organophosphorus nitrogen porous polymer. (3) Dissolve the metal component precursor in a solvent to obtain a solution containing the metal component, add the organophosphorus nitrogen porous polymer, stir at room temperature for 0.5-20 h, then heat to 50-80℃ and continue stirring for 0.5-20 h, cool to room temperature and filter, dry at 50℃ for 5 h to obtain the organophosphorus nitrogen porous polymer supported metal active component heterogeneous catalyst.

4. The application according to claim 3, characterized in that: The molar ratio of the organophosphine containing vinyl and phenyl groups, the pyridine containing vinyl groups, and the p-methylstyrene used in step (1) is 1:(0.5-5):(0.5-2); the free radical initiator is one of benzoyl peroxide and azobisisobutyronitrile; the ratio of the amount of the free radical initiator to the total weight of the organophosphine containing vinyl and phenyl groups, the pyridine containing vinyl groups, and the p-methylstyrene is 1:1000-1:

10.

5. The application according to claim 3, characterized in that: The solvent in step (1) is one or more of benzene, toluene, tetrahydrofuran, methanol, ethanol, methyl acetate, and methyl tert-butyl ether.

6. The application according to claim 3, characterized in that: The metal precursor in step (3) is one or more of Co(NO3)2, CoCl2, Co(OAc)2, Co(acac)2, Co(OH)2, PdCl2, Pd(NO3)2, H2PdCl4, and Pd(OAc)2; the solvent is one or more of methanol, ethanol, methyl acetate, and methyl tert-butyl ether.

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