CN114377721A - Preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction - Google Patents

Preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction Download PDF

Info

Publication number
CN114377721A
CN114377721A CN202011138810.5A CN202011138810A CN114377721A CN 114377721 A CN114377721 A CN 114377721A CN 202011138810 A CN202011138810 A CN 202011138810A CN 114377721 A CN114377721 A CN 114377721A
Authority
CN
China
Prior art keywords
catalyst
reaction
tud
rare earth
temperature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202011138810.5A
Other languages
Chinese (zh)
Inventor
吴剑
张亚茹
张旭
袁霞
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xiangtan University
Original Assignee
Xiangtan University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Xiangtan University filed Critical Xiangtan University
Priority to CN202011138810.5A priority Critical patent/CN114377721A/en
Publication of CN114377721A publication Critical patent/CN114377721A/en
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/89—Silicates, aluminosilicates or borosilicates of titanium, zirconium or hafnium
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D301/00—Preparation of oxiranes
    • C07D301/02—Synthesis of the oxirane ring
    • C07D301/03—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds
    • C07D301/19—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with organic hydroperoxides
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D303/00—Compounds containing three-membered rings having one oxygen atom as the only ring hetero atom
    • C07D303/02—Compounds containing oxirane rings
    • C07D303/04—Compounds containing oxirane rings containing only hydrogen and carbon atoms in addition to the ring oxygen atoms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/10—After treatment, characterised by the effect to be obtained
    • B01J2229/18—After treatment, characterised by the effect to be obtained to introduce other elements into or onto the molecular sieve itself
    • B01J2229/183—After treatment, characterised by the effect to be obtained to introduce other elements into or onto the molecular sieve itself in framework positions

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Epoxy Compounds (AREA)

Abstract

The invention discloses a preparation method of a mesoporous catalyst and application of the mesoporous catalyst in olefin epoxidation reaction. The method adopts an in-situ synthesis method to introduce lanthanide rare earth metal into a TUD-1 carrier, partially removes the rare earth metal through acid treatment, then performs chemical vapor deposition reaction with a titanium-containing compound, and performs silanization hydrophobic treatment to prepare the mesoporous catalyst. The method realizes that the lanthanide rare earth metal is controlled within a proper content range through partial removal, which not only can be beneficial to the subsequent vapor deposition of Ti and the promotion of the Ti content of the catalyst, but also can coordinate and stabilize the structure of the catalyst, reduce the negative influence of an acid site of the catalyst on the epoxidation reaction, and weaken the ineffective decomposition of the catalyst on alkyl hydroperoxide, thereby effectively improving the selectivity of the product and having better industrial application prospect.

Description

Preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction
Technical Field
The invention relates to a preparation method of a mesoporous catalyst and application of the mesoporous catalyst in epoxidation reaction of olefin and alkyl hydroperoxide.
Background
The 1, 2-epoxy compound is used as an important intermediate for fine chemicals and drug synthesis, is widely applied to related industries such as medicines, surfactants, polymers and the like, and is a product with special importance and wide application. Generally, 1, 2-epoxy compounds are prepared by epoxidation of olefins using chlorohydrin, direct oxidation of hydrogen peroxide, and co-oxidation. The co-oxidation method takes alkyl hydrogen peroxide as an oxygen source to carry out epoxidation reaction with olefin, is economic and environment-friendly, has gradually increased capacity ratio and good development prospect.
Efficient catalysts are one of the key points of research by researchers as a key to epoxidation reactions. Homogeneous catalysts, such as transition metal complexes (e.g., manganese, iron, cobalt and molybdenum), have high catalytic activity, however, their separation and recovery from the reaction system is often difficult, thereby incurring additional costs. Heterogeneous catalysts can overcome this disadvantage and also exhibit satisfactory catalytic activity during catalytic reactions, with molybdenum-based and titanium-based catalysts being the most widely studied and having high catalytic activity and selectivity in the epoxidation of olefins with organic peroxides. The titanium-containing porous silicon oxide material is used as one of heterogeneous catalysts, has good catalytic activity on selective oxidation of olefins, and is often used as a catalyst for preparing 1, 2-epoxy compounds by selective oxidation of olefins.
Among the titanium-containing catalysts, there are microporous titanium-containing catalysts TS-1, Ti-ZSM-48, Ti-Beta, Ti-MWW, etc., and mesoporous titanium-containing catalysts Ti-MCM-41, Ti-SBA-15, Ti-HMS, etc. Among the microporous titanium-containing catalysts, TS-1 has been the most studied, but the catalysts have a long preparation period and a high preparation cost, and can be used only for catalyzing small molecular substances, and have poor effects in catalyzing large molecular olefins having a high carbon number (e.g., styrene, etc.) or/and epoxidation reactions using alkyl hydroperoxide as an oxygen source, so that the applications are limited.
The mesoporous titanium-silicon catalyst has larger aperture, pore volume and specific surface area, can obviously reduce the diffusion resistance among pores in the macromolecular reaction process, enables reactant molecules to be more easily diffused into a pore channel and contacted with a catalytic active center, enables a product to be more easily separated from the diffusion pore channel, and is particularly suitable for medium-macromolecule catalytic reaction with diffusion limitation. TUD-1 is a novel mesoporous material, compared with other mesoporous materials (such as MCM-41, SBA-15 and the like), TUD-1 has low preparation cost and adjustable aperture parameters, and has the characteristics of high specific surface area, high hydrothermal performance and high mechanical stability, thereby having certain advantages. At present, Ti-TUD-1 is mainly prepared by a hydrothermal synthesis method, the preparation process is complex, the hydrolysis speed of a titanium source and a silicon source is difficult to match, titanium is difficult to enter a framework to form highly dispersed active sites, and the activity of the catalyst is low. The prepared catalyst has highly dispersed active sites, good catalytic activity, simple preparation and good repeatability by adopting a chemical vapor deposition method.
The modification method of the titanium-silicon catalyst used in the olefin epoxidation reaction mainly comprises silanization modification, acid modification, salt modification and the like, and the silanization modification can improve the surface hydrophobicity of the titanium-silicon material, so that the catalyst can adsorb reaction substrates more easily, and the catalytic activity is improved; the acid modification and the salt modification can reduce the content of non-skeleton titanium in the catalyst and reduce the acidity of the catalyst, so that the catalytic performance of the catalyst can be improved, the ring-opening reaction of an epoxy compound can be reduced, and the selectivity can be improved.
Disclosure of Invention
The invention provides a preparation method of a mesoporous catalyst and application of the mesoporous catalyst in olefin epoxidation reaction. The preparation process of the invention comprises four steps of in-situ synthesis of a carrier doped with lanthanide rare earth metal, partial removal of the lanthanide rare earth metal in the carrier, chemical vapor deposition and liquid phase silanization. According to the invention, lanthanide rare earth metal is introduced into the TUD-1 carrier by an in-situ synthesis method, the dispersity is good, the removal treatment can not only remove rare earth metal oxides on the surface of the carrier and in pore channels, but also remove part of framework rare earth metal, so that hydroxyl nest is generated, more four-coordinate Ti (IV) can be generated in the vapor deposition process, and meanwhile, the residual part of rare earth metal can inhibit acid sites of the catalyst, reduce the ineffective decomposition of the catalyst on alkyl hydroperoxide, and improve the catalytic activity. The obtained catalyst has better effect in catalyzing the epoxidation reaction of olefin and alkyl hydroperoxide solution.
The purpose of the invention is realized by the following steps:
a preparation method of a catalyst passing through mesoporous pores comprises the following three steps:
(1) partially removing lanthanide rare earth metals in the TUD-1 carrier doped with lanthanide rare earth metals to obtain a carrier partially removed with the lanthanide rare earth metals;
(2) pretreating the carrier obtained in the step (1) in a nitrogen atmosphere, carrying out chemical vapor deposition reaction on the pretreated carrier and steam containing a titanium compound, purging with nitrogen after the reaction is finished, carrying out high-temperature roasting to obtain a catalyst after the chemical vapor deposition reaction, and finally carrying out silanization treatment to obtain the final product mesoporous catalyst.
Further, in the step (1), the partial removal mode is acid treatment, the used acid is one or more of hydrochloric acid, nitric acid, sulfuric acid and acetic acid, the treatment temperature is 30-140 ℃, and the treatment time is 1-36 hours.
Further, in the step (1), the lanthanide metal-doped TUD-1 support is obtained by uniformly mixing tetraethoxysilane, triethanolamine, tetraethylammonium hydroxide, water, and a lanthanide metal compound at room temperature to form a homogeneous solution, and then aging, drying, heat-treating, and calcining.
Further, the mass ratio of ethyl orthosilicate, triethanolamine, tetraethylammonium hydroxide, water, and the lanthanide rare-earth metal compound is 1: (0.1-4): (0.1-2): (1-35): (0.001-0.1), the lanthanide rare earth metal is one or more than two of lanthanum, cerium, praseodymium and neodymium, and the lanthanide rare earth metal compound can be one or more than two of nitrate, sulfate, acetate, carbonate, chloride, fluoride, hydroxide and acetylacetone complex.
Further, the aging temperature is 20-65 ℃, and the time is 12-72 hours; drying at 65-150 ℃ for 12-48 h; the particle size of the gel during heat treatment is 1-5000 microns, the heat treatment temperature is 70-280 ℃, the heat treatment time is 2-12 hours, the calcination temperature is 400-800 ℃, and the calcination time is 6-18 hours.
Further, in the step (2), in the process of carrying out chemical vapor deposition reaction on the steam containing the titanium compound, the reaction temperature is 500-800 ℃, and the reaction time is 0.5-5 h; steam of titanium-containing compound andN2the carrier is carried in, and the particle size of the carrier is in the range of 1-1000 μm, preferably 10-200 μm. And roasting after the reaction is carried out in a nitrogen atmosphere or an air atmosphere, wherein the roasting temperature is 500-900 ℃, and the roasting time is 4-12 h.
Further, in the step (2), the silanization treatment adopts a liquid phase silanization mode, the catalyst after chemical vapor deposition is reacted with organic silicon in an organic solvent, wherein the organic silicon solution is one or more of hexamethyldisilazane, hexamethylchlorosilazane, heptamethylchlorosilazane, trimethylchlorosilane, dimethylchlorosilane, tetramethyldisilazane, dimethyldiethoxysilane, trimethylmethoxysilane, dimethyldimethoxysilane, trimethylethoxysilane, silylamine and N-trimethylsilylimidazole, and the amount of the organic silicon is 1-100% of the weight of the catalyst; the organic solvent is benzene, toluene, xylene, cumene, n-butane, isobutane, pentane, n-hexane, cyclohexane and heptane, preferably one or more than two of benzene, toluene, cumene and cyclohexane, and the dosage is 1-100 times of the weight of the catalyst; the reaction temperature of the silanization treatment is 80-180 ℃, and the reaction time is 1-10 h.
The application of the mesoporous catalyst in the co-oxidation reaction of olefin and alkyl hydroperoxide solution is characterized in that the reaction temperature is 80-130 ℃, the reaction time is 0.5-5 h, the reaction pressure is 0.1-4 MPa, the mass fraction of the catalyst in the reaction solution is 0.5-5%, the mass fraction of the alkyl hydroperoxide in the solvent is 2-80%, preferably 5-50%, and the mass ratio of the olefin to the alkyl hydroperoxide is (0.5-20): 1.
further, an oxygen source is mixed with a solvent and added into a catalytic reaction system in the form of solution, wherein the alkyl hydroperoxide is cumene hydroperoxide, cyclohexyl hydroperoxide, tert-butyl hydroperoxide or ethylbenzene hydroperoxide; the solvent is isopropyl benzene, cyclohexane, tert-butyl alcohol, 1, 2-dichloroethane or ethylbenzene, the olefin is C3~C10An alkene or cycloalkene of (a).
The invention has the beneficial effects that:
(1) the method partially removes the lanthanide rare earth metal-doped TUD-1 carrier to generate hydroxyl nests, so that more Ti can enter the catalyst in the chemical vapor deposition process.
(2) After the carrier is treated by acid, lanthanide rare earth metal in the carrier can not be completely removed, but is maintained in a certain content range, so that the lanthanide rare earth metal is controlled in a proper content range, the subsequent vapor deposition of Ti can be facilitated, the Ti content of the catalyst can be improved, the structure of the catalyst can be coordinated and stabilized, the negative influence of an acid site of the catalyst on an epoxidation reaction can be reduced, the ineffective decomposition of the catalyst on alkyl hydroperoxide can be weakened, and the selectivity of a product can be effectively improved.
(3) According to the invention, lanthanide rare earth metal is doped into the TUD-1 carrier by adopting an in-situ synthesis method, so that the influence on the pore structure of the carrier is small, and the dispersion degree is good. Due to the amorphous nature of the TUD-1 material, the amorphous mesoporous structure of the catalyst is not substantially destroyed before and after the support is partially stripped of the rare earth metals.
(4) The mesoporous TUD-1 material with partial rare earth metal removed is used as a carrier, so that the mesoporous TUD-1 material has high specific surface area and hydrothermal stability, the pore size can be regulated and controlled, and meanwhile, the mesoporous TUD-1 material is relatively simple to synthesize and low in cost, has higher activity in catalyzing the reaction of olefin molecules with different kinetic diameters and alkyl hydrogen peroxide, and has better application prospect. The unique three-dimensional mesoporous pore channel structure of TUD-1 has small change before and after modification, the structure is beneficial to depositing more titanium components in the chemical vapor deposition process, and the good mass transfer performance of the structure enables the structure to have higher catalytic activity in catalytic reaction.
(5) The invention adopts a chemical vapor deposition method to carry out chemical vapor deposition reaction on a carrier modified by rare earth metal and titanium-containing compound steam to prepare the catalyst after chemical vapor deposition. The method can prepare the catalyst with highly dispersed active sites and has good catalytic performance.
(6) The obtained catalyst for the chemical vapor deposition reaction is subjected to silanization modification after roasting, so that the hydrophobicity of the surface of the catalyst is increased, meanwhile, organosilane groups on the surface of the catalyst are easier to approach and adsorb olefin and alkyl hydroperoxide molecules, and the catalytic activity of the catalyst is improved; meanwhile, the grafted silane group can reduce the weak acidity of the surface of the catalyst and reduce the occurrence of side reactions, thereby improving the epoxidation selectivity.
In a word, the catalyst prepared by the preparation method provided by the invention can obtain a very good technical effect in catalyzing the epoxidation reaction of olefin and alkyl hydrogen peroxide solution, and the preparation method is relatively simple, low in preparation cost, good in reproducibility and good in industrial application prospect.
Detailed Description
The present invention is further illustrated by the following specific examples, which should be noted that the following examples are only illustrative and the present invention is not limited thereto.
Example 1
Preparation of La-Ti-TUD-1(De) modified catalyst
1.46gLa (NO)3)3·6H2O dissolved in 11.03g H2O, then uniformly mixing with 25.06g of TEA, dropwise adding the mixture into 35.00g of TEOS, stirring for 30min, dropwise adding 29.69g of TEAOH solution with the mass fraction of 25%, and stirring for 3h to form a homogeneous transparent solution; aging at room temperature in dark place for 48 h; drying for 24h in a drying oven at 100 ℃ by air blast; grinding the dried solid to the particle size of below 2mm and placing the solid in a homogeneous reactor to carry out dynamic heat treatment for 8 hours at 180 ℃; and finally, placing the solid after the heat treatment in a muffle furnace, and roasting for 10h at the temperature of 600 ℃ at the temperature of 5 ℃/min to prepare the carrier La-TUD-1 doped with the metal La. 5g of La-TUD-1 and 150mL of a 3mol/L nitric acid solution were put in a three-necked flask, and subjected to La removal treatment by stirring under reflux at 100 ℃ for 1 hour. And after the La removal is finished, filtering the solid while the solid is hot, washing the solid for multiple times until the solid is neutral, placing the solid in a vacuum drying oven, and drying the solid for 12 hours at 120 ℃ to obtain La-TUD-1(De) modified by La removal. Taking 4g of La-TUD-1(De) with the particle size of 100-300 mu m, placing the La-TUD-1(De) in a tube furnace, and adding the N in an amount of 200mL/min2Heating to 400 ℃ in atmosphere for pretreatment for 2h, then heating to 700 ℃ and adding N at 100mL/min2Introducing saturated TiCl at 150 ℃ under the atmosphere4Steam for 1.5h, then the flow rate of N2 is switched to 200mL/min to purge to room temperature,and finally, taking out and placing in a muffle furnace, and roasting for 6h when the temperature is increased to 600 ℃ at the speed of 10 ℃/min to obtain the catalyst after chemical vapor deposition. Dispersing 3.0g of catalyst subjected to chemical vapor deposition into 50.0g of toluene, then adding 1.5g of hexamethyldisilazane into the suspension, refluxing and stirring at 110 ℃ for 5h, cooling, performing suction filtration, washing the solid with 50mL of toluene for three times, and finally drying in a vacuum drying oven at 110 ℃ for 12h to prepare the La-Ti-TUD-1(De) modified catalyst with 1.32wt% of titanium, 0.52wt% of lanthanum and 18.1nm of average pore diameter. .
Example 2
Preparation of Ce-Ti-TUD-1(De) modified catalyst
0.34g of CeCl was taken3Dissolving in 12.11g H2After O, uniformly mixing with 25.42g of TEA, dropwise adding the mixture into 36.00g of TEOS, stirring for 30min, dropwise adding 30.12g of TEAOH solution with the mass fraction of 25%, and stirring for 2.5h to form a homogeneous transparent solution; aging at room temperature in dark place for 24 h; drying with 100 deg.C air blast for 36 h; after grinding, taking a rubber block with the particle size of 900-2000 mu m, and dynamically heat treating for 6 hours at 170 ℃ in a homogeneous reactor; and finally, roasting the mixture for 9 hours at the temperature rise rate of 5 ℃/min and 700 ℃ in a muffle furnace to prepare the Ce-TUD-1 doped metal. Adding 5gCe-TUD-1 into 200mL of 5mol/L HCl solution, heating, refluxing and stirring at 80 ℃ for 12h, carrying out suction filtration while the solution is hot, and drying at 120 ℃ for 6h to obtain the carrier Ce-TUD-1(De) for removing the metal Ce. 4g of Ce-TUD-1(De) with the grain diameter of 100-300 mu m is placed in a tube furnace at 200ml/minN2After pretreatment at 400 ℃ for 2h at the flow rate, the temperature is rapidly raised to 600 ℃ at 100mL/minN2Introducing 150 ℃ saturated TiCl at a flow rate4Steam for 2h at 200mL/minN2Blowing at a flow rate, cooling to room temperature, taking out, and finally roasting in a muffle furnace at a heating rate of 10 ℃/min and 700 ℃ for 5h to obtain the catalyst after chemical vapor deposition. 3.0g of the catalyst after the chemical vapor deposition was dispersed in 50.0g of toluene, and then 1.5g of hexamethyldisilazane was added to the suspension, followed by stirring at 120 ℃ under reflux for 5 hours. The obtained powder was filtered, washed three times with 50ml of toluene, and then dried in a vacuum oven at 110 ℃ for 12 hours to obtain a silanized catalyst Ce-Ti-TUD-1(De) having a titanium content of 1.35wt%, a cerium content of 0.58wt%, and an average pore diameter of 18.0 nm.
Example 3
Preparation of praseodymium-removed modified catalyst Pr-Ti-TUD-1(De)
The procedure is as in example 1, except that the doped lanthanide metal compound is PrCl3The silanization process is as follows: 3.0gPr-Ti-TUD-1 was dispersed in 50.0g of cyclohexane, and then trimethylchlorosilane in an amount of 1.5 times the mass of the catalyst was added to the suspension, followed by stirring at 120 ℃ under reflux for 6 hours. The resulting powder was filtered, washed three times with 50ml of cyclohexane, and then dried in a vacuum oven at 100 ℃ for 12 hours to obtain a silylated catalyst Pr-Ti-TUD-1 (De). The titanium content is 1.33%, the praseodymium content is 0.53%, and the average pore diameter is 18.1 nm.
Example 4
The catalysts prepared in examples 1,2 and 3 were used in the epoxidation of 1-pentene and Cumene Hydroperoxide (CHP) solution, and the reaction was carried out in a batch reactor. Adding 0.32g of catalyst into a reaction kettle, then adding 6.14g of cumene hydroperoxide oxidizing solution with the mass percent of 20 percent, finally adding 4.72g of 1-pentene, sealing the kettle, filling nitrogen to 1.5MPa, and reacting for 1h at the temperature of 120 ℃. After the reaction is finished, cooling the reaction product in ice water bath to below 5 ℃, opening an outlet valve of the reaction kettle, absorbing the released gas by the cumene, and then emptying the reaction kettle. And mixing the reaction liquid with the tail gas absorption liquid cumene for analysis and detection.
The content of cumene hydroperoxide before and after the reaction is titrated and analyzed by an iodometry method, the content of 1, 2-epoxy pentane generated by the reaction is analyzed by a gas chromatography internal standard method, and an internal standard substance is isooctane. The reaction results are shown in table 1.
TABLE 1 results of epoxidation of 1-pentene with cumene by peroxidation with different catalysts
Catalyst and process for preparing same CHP conversion% 1, 2-Oxopentane Selectivity%
La-Ti-TUD-1(De) 97.5 92.6
Ce-Ti-TUD-1(De) 94.3 90.6
Pr-Ti-TUD-1(De) 97.1 89.1
Example 5
The catalysts prepared in examples 1,2 and 3 were used in the epoxidation of propylene and cumene hydroperoxide solution, and the reaction was carried out in a batch reactor. The rotor, 0.30g of catalyst and 6.13g of cumene hydroperoxide oxidizing solution with the mass percent of 25 percent are added into a reaction kettle in sequence, then the reaction kettle is sealed, and 5.3g of propylene is added into the kettle in a liquid state through a advection pump. And (3) after leak detection, placing the mixture in an oil bath pot for reaction, reacting for 2 hours at the temperature of 90 ℃ under the self pressure, placing the mixture in ice water after the reaction is finished, cooling the mixture to the temperature below 5 ℃, discharging unreacted propylene through an exhaust valve, absorbing the unreacted propylene by using isopropylbenzene, and then emptying the propylene. And when determining that no residual gas exists in the reaction kettle, removing the reaction liquid for qualitative and quantitative analysis.
And analyzing the content of cumene hydroperoxide in the reaction solution by an iodometry method, and analyzing the content of propylene oxide generated by the reaction by a gas chromatography internal standard method, wherein an internal standard substance is n-hexane. The reaction results are shown in table 2.
TABLE 2 results of epoxidation of propylene with cumene hydroperoxide catalyzed by different catalysts
Catalyst and process for preparing same CHP conversion% Selectivity to propylene oxide%
La-Ti-TUD-1(De) 98.5 99.6
Ce-Ti-TUD-1(De) 95.6 98.1
Pr-Ti-TUD-1(De) 95.3 92.1
Example 6
The catalysts prepared in examples 1,2 and 3 were used in epoxidation of propene with a solution of Cyclohexylhydroperoxide (CHHP), and the reaction was carried out in a batch reactor. 0.58g of catalyst is added into a reaction kettle, 6.92g of cyclohexyl hydrogen peroxide oxidizing solution with the mass percent of 14.5 percent is added into the reaction kettle, the reaction kettle is sealed, and then 5.1g of propylene is added into the reaction kettle in a liquid state through a constant flow pump. And (3) after leakage detection, placing the mixture into an oil bath pot for reaction, reacting for 2 hours at the temperature of 90 ℃ under the self pressure, placing the mixture into ice water after the reaction is finished, cooling the mixture to the temperature below 5 ℃, discharging unreacted propylene through an exhaust valve, absorbing the unreacted propylene by cyclohexane, and then emptying the mixture. And when determining that no residual gas exists in the reaction kettle, removing the reaction liquid for qualitative and quantitative analysis.
Analyzing the content of cyclohexyl hydroperoxide in the reaction solution by an iodometry method, and analyzing the content of propylene oxide generated by the reaction by a gas chromatography internal standard method, wherein the internal standard substance is n-pentane. The reaction results are shown in Table 3.
TABLE 3 results of epoxidation of propylene with cyclohexyl hydroperoxide catalyzed by different catalysts
Catalyst and process for preparing same CHHP conversion% Selectivity to propylene oxide%
La-Ti-TUD-1(De) 94.0 69.4
Ce-Ti-TUD-1(De) 93.2 65.0
Pr-Ti-TUD-1(De) 89.4 60.1
Comparative example 1
Preparation and catalytic performance of Ti-TUD-1 (S):
take 11.03g H2Uniformly mixing O and 25.06g of TEA, dropwise adding the mixture into 35.00g of TEOS, stirring for 0.5h, dropwise adding 29.69g of TEAOH solution with the mass fraction of 25%, and stirring for 2h to form a homogeneous transparent solution; aging at room temperature in dark place for 48 h; drying for 24h in a drying oven at 100 ℃ by air blast; carrying out dynamic heat treatment for 8h after grinding; and finally, roasting the powder in a muffle furnace at the heating rate of 5 ℃/min for 10 hours at the temperature of 600 ℃ to obtain the TUD-1. 4g of TUD-1 was placed in a tube furnace at 200ml/min N2Pretreatment at 400 ℃ under flow rateAfter 2h, the temperature was rapidly raised to 700 ℃ at 100ml/minN2Introducing 150 ℃ saturated TiCl at a flow rate4Steam for 1.5h at 200ml/min N2Blowing at a flow rate, cooling to room temperature, taking out, and finally roasting in a muffle furnace at a heating rate of 10 ℃/min and a temperature of 600 ℃ for 6h to obtain Ti-TUD-1. 3.0g of the above Ti-TUD-1 was dispersed in 50.0g of toluene, and then HMDS in an amount of 0.5 times the mass of the catalyst was added to the suspension, followed by stirring under reflux at 140 ℃ for 5 hours under a nitrogen atmosphere. The resulting powder was filtered, washed three times with 50ml of toluene, and then dried in a vacuum oven at 110 ℃ for 12 hours to obtain Ti-TUD-1 (S). The titanium content is 1.19%, and the average pore diameter is 23.5 nm.
The procedure of example 4 was followed to obtain a catalyst that, in catalyzing the epoxidation of 1-pentene with a solution of cumene hydroperoxide, gave a cumene hydroperoxide conversion of 90.3% and a 1, 2-cyclopentane epoxide selectivity of 84.8%. According to the reaction procedure of example 5, the catalyst obtained was used to catalyze the epoxidation of propylene with a cumene hydroperoxide solution, with a cumene hydroperoxide conversion of 97.3% and a propylene oxide selectivity of 83.2%. According to the reaction procedure of example 6, the catalyst obtained was used to catalyze the epoxidation of propylene with a solution of cyclohexylhydroperoxide, with a conversion of 92.2% of cyclohexylhydroperoxide and a selectivity of 57.1% of propylene oxide.
Comparative example 2
Preparation and catalytic performance of La-Ti-TUD-1(S) catalyst:
take 0.25gLa (NO)3)3·6H2O dissolved in 11.03g H2After O, uniformly mixing with 25.06g of TEA, dropwise adding the mixture into 35.00g of TEOS, stirring for 30min, dropwise adding 29.69g of TEAOH solution with the mass fraction of 25%, and stirring for 2.5h to form a homogeneous transparent solution; aging at room temperature in dark place for 48 h; drying for 24h in a drying oven at 100 ℃ by air blast; after grinding, taking a rubber block with the particle size of 900-2000 mu m, and dynamically heat treating for 8 hours at 180 ℃ in a homogeneous reactor; and finally, roasting the mixture for 10 hours in a muffle furnace at the temperature rise rate of 5 ℃/min and the temperature rise rate of 600 ℃ to prepare the carrier La-TUD-1 doped with the metal La. Taking 4g of carrier La-TUD-1 with the particle size of 100-300 mu m, placing the carrier La-TUD-1 in a tube furnace at 200ml/minN2After pretreatment at 400 ℃ for 2h at the flow rate, the temperature is rapidly raised to 700 ℃ at 100ml/minN2Introducing 150 ℃ saturated TiCl at a flow rate4Steam for 1.5h at 200ml/min N2Blowing at a flow rate, cooling to room temperature, taking out, and finally roasting in a muffle furnace at a heating rate of 10 ℃/min and 600 ℃ for 6h to obtain the catalyst La-Ti-TUD-1 after chemical vapor deposition. 3.0g of La-Ti-TUD-1 was dispersed in 50.0g of toluene, and then hexamethyldisilazane (0.5 times the mass of the catalyst) was added to the suspension, followed by reflux stirring at 140 ℃ for 5 hours. The resulting powder was filtered, washed three times with 50ml of toluene, and then dried in a vacuum oven at 110 ℃ for 12 hours to obtain a silylated catalyst La-Ti-TUD-1 (S). The titanium content is 1.53%, the lanthanum content is 0.65%, and the average pore diameter is 12.2 nm.
The procedure of example 4 was followed to obtain a catalyst which, in catalyzing the epoxidation of 1-pentene with a solution of cumene hydroperoxide, gave a cumene hydroperoxide conversion of 99.5% and a 1, 2-cyclopentane epoxide selectivity of 89.4%. According to the reaction procedure of example 5, the catalyst obtained was used to catalyze the epoxidation of propylene with a cumene hydroperoxide solution, with a cumene hydroperoxide conversion of 99.6% and a propylene oxide selectivity of 91.8%. According to the reaction procedure of example 6, the catalyst obtained was used to catalyze the epoxidation of propylene with a solution of cyclohexylhydroperoxide, with a conversion of 93.7% of cyclohexylhydroperoxide and a selectivity of propylene oxide of 61.1%.
Comparative example 3
Preparation and catalytic Properties of La-Ti (im) -TUD-1 (De):
following the preparation of example 1, after the La modified La (I) -TUD-1(Dela) carrier was obtained, 3.0g of the carrier was placed in a three-necked flask, and 50mL of 20g/L TiCl was added4And (3) soaking the ethanol solution at 35 ℃ for 4h in a nitrogen atmosphere, and then evaporating the solution to dryness to obtain the titanium-coated catalyst. The catalyst impregnated with titanium was calcined in a muffle furnace at a heating rate of 2 ℃/min at 600 ℃ for 10 hours, and then the silanization treatment of example 1 was carried out to obtain La-Ti (im) -TUD-1(De) impregnated with titanium catalyst. The titanium content was 1.62wt%, the lanthanum content was 0.51wt%, and the average pore diameter was 18.1 nm.
The catalyst obtained according to the procedure of example 4 exhibited 62.1% conversion of cumene hydroperoxide and 78.2% selectivity to 1, 2-cyclopentane epoxide in catalyzing the epoxidation of 1-pentene with a solution of cumene hydroperoxide. According to the reaction procedure of example 5, the catalyst obtained was used to catalyze the epoxidation of propylene with a cumene hydroperoxide solution, with a cumene hydroperoxide conversion of 64.2% and a propylene oxide selectivity of 71.5%. According to the reaction procedure of example 6, the catalyst obtained was used to catalyze the epoxidation of propylene with a solution of cyclohexylhydroperoxide, with a conversion of 41.8% of cyclohexylhydroperoxide and a selectivity of propylene oxide of 41.2%.
Compared with the Ti-TUD-1 catalyst (comparative example 1) prepared by direct vapor deposition, the pore diameter of the catalyst (comparative example 2) prepared by vapor deposition of Ti on the carrier doped with rare earth metal is slightly reduced, and the Ti content of the catalyst is improved. From the catalysts prepared in examples 1,2, 3 and 1, after doping with rare earth metals and then partially removing, the content of rare earth metals in the catalyst is substantially maintained at about 0.5wt%, the Ti content is further improved, the pore structure of the catalyst is not greatly changed, and the catalytic effect is further improved in the catalytic reactions of examples 4, 5 and 6.
As can be seen from example 1 and comparative example 2, the La content of the catalyst prepared by La removal of the carrier in example 1 is slightly lower (partially removed) than that of the catalyst prepared by La doping without partial removal in comparative example 2, but the titanium content of the catalyst prepared in example 1 is higher and the catalytic effect is better, which indicates that partial removal is beneficial to the subsequent vapor deposition of Ti. As can be seen from example 1 and comparative example 3, although the catalyst obtained by the impregnation method contained more Ti, the catalytic performance was poor, indicating that the catalytic effect was not dependent only on the Ti content. Therefore, the method can be known that the lanthanide rare earth metal is controlled within a proper content range through partial removal, so that the method is beneficial to subsequent vapor deposition of Ti, the content of Ti is improved, the structure of the catalyst can be coordinated and stabilized, the negative influence of an acid site of the catalyst on an epoxidation reaction is reduced, the ineffective decomposition of the catalyst on alkyl hydroperoxide is weakened, and the selectivity of the product is effectively improved.

Claims (10)

1. The preparation method of the mesoporous catalyst is characterized by comprising the following steps:
(1) partially removing lanthanide rare earth metals in the TUD-1 carrier doped with lanthanide rare earth metals to obtain the TUD-1 carrier partially removed with the lanthanide rare earth metals;
(2) pretreating the carrier obtained in the step (1) in a nitrogen atmosphere, then carrying out chemical vapor deposition reaction with steam containing a titanium compound, purging with nitrogen after the reaction is finished, cooling, and carrying out high-temperature roasting and silanization treatment to obtain the final product mesoporous catalyst.
2. The method for preparing the mesoporous catalyst according to claim 1, wherein in the step (1), the partial removal of the lanthanide rare earth metal is performed by acid treatment, the acid is one or more of hydrochloric acid, nitric acid, sulfuric acid and acetic acid, the treatment temperature is 30-140 ℃, and the treatment time is 1-36 hours.
3. The method for preparing a mesoporous catalyst according to claim 1 or 2, wherein, in the step (1), the lanthanide-doped TUD-1 support is prepared by uniformly mixing tetraethoxysilane, triethanolamine, tetraethylammonium hydroxide, water, and a lanthanide compound at room temperature to form a homogeneous solution, and then aging, drying, heat-treating, and calcining.
4. The method for preparing a mesoporous catalyst according to claim 3, wherein in the step (1), the ratio of the amounts of the substances of ethyl orthosilicate, triethanolamine, tetraethylammonium hydroxide, water and the lanthanide rare earth metal compound is 1: (0.1-4): (0.1-2): (1-35): (0.001-0.1).
5. The method for preparing a mesoporous catalyst according to claim 3, wherein in the step (1), the lanthanide metal is one or more of lanthanum, cerium, praseodymium and neodymium, and the compound thereof is one or more of nitrate, sulfate, acetate, carbonate, chloride, fluoride, hydroxide and acetylacetone complex.
6. The preparation method of the mesoporous catalyst according to claim 3, wherein in the step (1), the aging temperature is 20-65 ℃ and the aging time is 12-72 hours; drying at 65-150 ℃ for 12-48 h; the heat treatment temperature is 70-280 ℃, the heat treatment time is 2-12 h, the roasting temperature is 400-800 ℃, and the roasting time is 6-18 h.
7. The method for preparing the mesoporous catalyst according to claim 1 or 2, wherein in the step (2), the reaction temperature is 500-800 ℃ and the reaction time is 0.5-5 h in the process of performing the chemical vapor deposition reaction with the vapor of the titanium-containing compound; the steam containing the titanium compound enters by being entrained by nitrogen, and the particle size of the carrier is 1-1000 mu m; and roasting after the reaction is carried out in a nitrogen atmosphere or an air atmosphere, wherein the roasting temperature is 500-900 ℃, and the roasting time is 4-12 h.
8. The preparation method of the mesoporous catalyst according to claim 1 or 2, characterized in that in the step (3), the silylation treatment is liquid phase silylation, the catalyst after chemical vapor deposition is reacted with organosilicon in an organic solvent, the reaction temperature of the silylation treatment is 80-180 ℃, and the reaction time is 1-10 h, wherein the organosilicon is one or more of hexamethyldisilazane, hexamethylchlorosilazane, heptamethylchlorosilazane, trimethylchlorosilane, dimethylchlorosilane, tetramethyldisilazane, dimethyldiethoxysilane, trimethylmethoxysilane, dimethyldimethoxysilane, trimethylethoxysilane, silylamine and N-trimethylsilylimidazole, and the amount of the organosilicon is 1-100% of the weight of the catalyst; the organic solvent is benzene, toluene, xylene, cumene, n-butane, isobutane, pentane, n-hexane, cyclohexane and heptane, preferably one or more of benzene, toluene, cumene and cyclohexane, and the dosage of the organic solvent is 1-100 times of the weight of the catalyst.
9. Use of the mesoporous catalyst prepared by the preparation method of any one of claims 1 to 8 in olefin epoxidation reaction.
10. The application of the method as claimed in claim 9, wherein the oxygen source of the epoxidation reaction is alkyl hydroperoxide, the reaction temperature is 80-130 ℃, the reaction time is 0.5-5 h, the reaction pressure is 0.1-4 MPa, the mass fraction of the catalyst in the reaction solution is 0.5-5%, the mass fraction of the alkyl hydroperoxide in the solvent is 2-80%, and the mass ratio of the olefin to the alkyl hydroperoxide is (0.5-20): 1; mixing an oxygen source and a solvent, and adding the mixture into a catalytic reaction system in a solution form, wherein the alkyl hydroperoxide is cumene hydroperoxide, cyclohexyl hydroperoxide, tert-butyl hydroperoxide or ethylbenzene hydroperoxide; the solvent is isopropyl benzene, cyclohexane, tert-butyl alcohol, 1, 2-dichloroethane or ethylbenzene, the olefin is C3~C10An alkene or cycloalkene of (a).
CN202011138810.5A 2020-10-22 2020-10-22 Preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction Pending CN114377721A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011138810.5A CN114377721A (en) 2020-10-22 2020-10-22 Preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011138810.5A CN114377721A (en) 2020-10-22 2020-10-22 Preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction

Publications (1)

Publication Number Publication Date
CN114377721A true CN114377721A (en) 2022-04-22

Family

ID=81193314

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011138810.5A Pending CN114377721A (en) 2020-10-22 2020-10-22 Preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction

Country Status (1)

Country Link
CN (1) CN114377721A (en)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1317991A (en) * 1998-09-14 2001-10-17 国际壳牌研究有限公司 Process for preparing catalysts with improved catalytic properties
DE102008056243A1 (en) * 2008-11-06 2010-05-12 Hölderich, Wolfgang, Prof. Dr. Preparation of phenol from benzene with aqueous hydrogen peroxide in the presence of a titanium-silicon-containing catalyst, which has zeolite structure with structural defect sites, useful as an intermediate for preparing chemicals
US20150191442A1 (en) * 2012-06-27 2015-07-09 University Of Kansas Alkylene epoxidation with mesoporous catalysts
CN105688974A (en) * 2016-01-11 2016-06-22 大唐南京环保科技有限责任公司 Denitration catalyst with SBA-15/TiO2 serving as carrier and preparing method thereof
CN109364980A (en) * 2018-11-13 2019-02-22 湘潭大学 A kind of preparation method and application preparing mesoporous catalyst by chemical vapour deposition technique carried metal titanium
CN109678172A (en) * 2019-01-09 2019-04-26 武汉工程大学 A kind of preparation method of titaniferous MWW structure molecular screen and its application of catalysis epoxidation
CN110694676A (en) * 2019-11-08 2020-01-17 湘潭大学 Chemical vapor deposition preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction
CN111346672A (en) * 2018-12-21 2020-06-30 中国科学院大连化学物理研究所 Method for preparing low-carbon olefin by catalyzing synthesis gas through heteroatom-doped molecular sieve

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1317991A (en) * 1998-09-14 2001-10-17 国际壳牌研究有限公司 Process for preparing catalysts with improved catalytic properties
DE102008056243A1 (en) * 2008-11-06 2010-05-12 Hölderich, Wolfgang, Prof. Dr. Preparation of phenol from benzene with aqueous hydrogen peroxide in the presence of a titanium-silicon-containing catalyst, which has zeolite structure with structural defect sites, useful as an intermediate for preparing chemicals
US20150191442A1 (en) * 2012-06-27 2015-07-09 University Of Kansas Alkylene epoxidation with mesoporous catalysts
CN105688974A (en) * 2016-01-11 2016-06-22 大唐南京环保科技有限责任公司 Denitration catalyst with SBA-15/TiO2 serving as carrier and preparing method thereof
CN109364980A (en) * 2018-11-13 2019-02-22 湘潭大学 A kind of preparation method and application preparing mesoporous catalyst by chemical vapour deposition technique carried metal titanium
CN111346672A (en) * 2018-12-21 2020-06-30 中国科学院大连化学物理研究所 Method for preparing low-carbon olefin by catalyzing synthesis gas through heteroatom-doped molecular sieve
CN109678172A (en) * 2019-01-09 2019-04-26 武汉工程大学 A kind of preparation method of titaniferous MWW structure molecular screen and its application of catalysis epoxidation
CN110694676A (en) * 2019-11-08 2020-01-17 湘潭大学 Chemical vapor deposition preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
黄慧文;张敏秀;陈晨;李春义;崔秋凯;: "铈改性Silicalite-1分子筛催化剂上甲醇制丙烯反应性能研究", 燃料化学学报 *

Similar Documents

Publication Publication Date Title
US6121187A (en) Amorphous, microporous mixed oxide catalysts with controlled surface polarity for selective heterogeneous catalysis, adsorption and material separation
CN100586566C (en) Method for preparing oxidation catalyst of cyclopropene
CN103357432B (en) A kind of mesoporous titanium-silicon molecular screen and its production and use
Yu et al. Insights into the efficiency of hydrogen peroxide utilization over titanosilicate/H2O2 systems
WO1996009117A1 (en) Heterogeneous catalysts
CN109675633B (en) Hydrophobic modified core-shell catalyst ZIF-67@ SiO2Method for preparing KA oil by catalytic cyclohexane oxidation
Holmes et al. Tetraneopentyltitanium derived supported catalysts: Part 1. Synthesis and catalytic properties for the epoxidation of cyclohexene with aqueous hydrogen peroxide
CN103395799A (en) Preparation method for titanium silicalite molecular sieve and applications
CN110694676A (en) Chemical vapor deposition preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction
CN110961089B (en) Preparation method of titanium-silicon composite oxide
CN108349918A (en) Catalyst preparation
CN108821304A (en) High activity multi-stage porous Titanium Sieve Molecular Sieve and its preparation method and application
CN111924852B (en) Preparation method of titanium-silicon molecular sieve
CN1166599C (en) Process for preparing nano catalyst used to prepare propene by oxidizing and dehydrogenating propane
CN113457727B (en) Alkali metal regulated hierarchical pore Au/ZSM-5 catalyst, and synthesis method and application thereof
CN105524018B (en) A kind of olefin epoxidation method
CN114377721A (en) Preparation method of mesoporous catalyst and application of mesoporous catalyst in olefin epoxidation reaction
CN113083299A (en) Yolk-shell bifunctional catalyst, preparation method thereof and application thereof in preparation of ethylene glycol by hydrogenolysis of glucose
Deng et al. Hydrophobic Ti–Si Xerogels: Catalysts for the Selective Epoxidation of Olefins and Allylic Alcohols
CN110092391B (en) Preparation method of titanium-containing molecular sieve with layered pillared structure and application of titanium-containing molecular sieve in catalytic epoxidation
CN109364980A (en) A kind of preparation method and application preparing mesoporous catalyst by chemical vapour deposition technique carried metal titanium
CN115106124A (en) Titanium-silicon molecular sieve solid-supported gold catalyst and preparation method and application thereof
CN111100054A (en) α' -dihydroxy-diisopropylbenzene, bis- (tert-butylperoxyisopropyl) benzene and epoxy compound synthesis method
Müller et al. Titania–silica epoxidation catalysts modified by acetoxypropyl groups
CN108786846A (en) Zirconium silicate modified sulfonic acid grafted mesoporous silica catalyst, and preparation method and application thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20220422