Preparation method of hanging tetrahydrodicyclopentadiene

Abstract

This invention relates to a method for preparing bridging tetrahydrodicyclopentadiene. The method includes: isomerizing bridging tetrahydrodicyclopentadiene dissolved in an organic solvent under a hydrogen atmosphere and with the aid of an MWW molecular sieve catalyst, wherein the aluminum content at the T2 site of the framework semi-supercage in the MWW molecular sieve catalyst is 10-15 wt% of the total aluminum content. This invention uses an MWW molecular sieve catalyst with an aluminum content of 10-15 wt% at the T2 site of the framework semi-supercage, which significantly improves the selectivity and yield of bridging tetrahydrodicyclopentadiene in the isomerization reaction. Specifically, the preferred embodiment of this invention can yield bridging tetrahydrodicyclopentadiene with a yield of over 98%.

Description

Technical Field

[0001] This invention relates to a method for preparing hanging tetrahydrodicyclopentadiene. Background Technology

[0002] Hangable tetrahydrodicyclopentadiene (THD) is a high-performance, high-density liquid hydrocarbon fuel with a low freezing point (-79°C), a suitable flash point (55°C), high bulk calorific value (39.6 MJ / L), and low toxicity. It can be used directly as a high-density hydrocarbon fuel or as a solvent or additive mixed with other high-density hydrocarbon fuels. It is widely used as a propellant for missiles, rockets, torpedoes, and other aircraft, and is the most versatile and best-performing high-density hydrocarbon fuel to date. Additionally, it can be used as a solvent or thinner for paints and surfactants, as well as in lubricants.

[0003] Generally, hanging tetrahydrodicyclopentadiene (exo-THDCPD) is prepared from its isomer, bridged tetrahydrodicyclopentadiene (endo-THDCPD), via isomerization. The isomerization of endo-THDCPD to prepare exo-THDCPD typically employs traditional strong L-acids, anhydrous aluminum chloride, solid superacids, supported aluminum chloride, heteropolyacids, and molecular sieve catalysts. Anhydrous aluminum chloride catalysts exhibit high activity, good selectivity, and mild reaction conditions; however, they readily form polymers, require large quantities, have short lifespans, and can only be used in batch reactions. Furthermore, during the reaction, anhydrous aluminum chloride reacts to form heavy components, resulting in complexes and generating substantial waste, preventing catalyst recycling. Post-treatment requires alkali neutralization, and the product separation and purification process is complex, with subsequent acidic wastewater polluting the environment. While supported aluminum chloride catalysts do not suffer from product separation issues, their preparation process is cumbersome, has high requirements for water and raw materials, and requires continuous chlorine replenishment during the reaction, significantly limiting the development of this method.

[0004] US3381046 discloses a method for synthesizing exo-THDCPD using concentrated sulfuric acid as a catalyst. Concentrated sulfuric acid is a highly corrosive acid, which requires sophisticated equipment and makes product separation and purification difficult, while also causing environmental pollution.

[0005] US4086284 and US4086286 both disclose a method for synthesizing exo-THDCPD via endo-THDCPD isomerization using dichloromethane as a solvent and anhydrous AlCl3 as a catalyst. However, the anhydrous AlCl3 catalyst cannot be reused because it can form complexes with reaction byproducts during the isomerization reaction, and the disposal of the catalyst generates a large amount of acidic wastewater, polluting the environment.

[0006] CN101786936A discloses a process for the gas-phase isomerization synthesis of exo-THDCPD using molecular sieves such as Y, Beta, mordenite, Al-MCM-41, Al-MCM-48, and Al-SBA-15. Although the process is simple and has a high yield of hydroisomerization, the catalyst deactivates quickly and requires a large amount of carrier gas, limiting its potential for industrial application.

[0007] CN106699499A discloses a method for improving the selectivity of endo-THDCPD isomerization using an ultrastable Y-type molecular sieve with high sodium content as a catalyst. Chlorinated organic compounds are added to the feedstock to achieve a single-pass conversion rate of over 95% and a yield of over 90% for bridged tetrahydrodicyclopentadiene isomerization. However, chlorinated organic compounds are toxic and will cause environmental pollution.

[0008] Therefore, there is an urgent need for a simple, efficient, and stable method for the hydroisomerization of bridged tetrahydrodicyclopentadiene to synthesize hanging tetrahydrodicyclopentadiene. Summary of the Invention

[0009] The purpose of this invention is to overcome the problems of low selectivity and low yield in the synthesis of hanging tetrahydrodicyclopentadiene in the prior art, and to provide a method for preparing hanging tetrahydrodicyclopentadiene with high selectivity and high yield.

[0010] To achieve the above objectives, the first aspect of the present invention provides a method for preparing bridged tetrahydrodicyclopentadiene, the method comprising: isomerizing bridged tetrahydrodicyclopentadiene dissolved in an organic solvent under a hydrogen atmosphere under the conditions of an MWW molecular sieve catalyst, wherein the content of aluminum at the T2 site of the framework semi-supercage in the MWW molecular sieve catalyst is 10-15 wt% of the total aluminum content.

[0011] Through the above technical solution, the present invention has the following advantages:

[0012] This invention uses MWW molecular sieve catalyst and controls the aluminum content at the T2 site of the framework semi-supercage in the molecular sieve to be 10-15 wt% of the total aluminum content, which can significantly improve the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction of bridged tetrahydrodicyclopentadiene. Specifically, the preferred scheme of this invention can obtain hanging tetrahydrodicyclopentadiene with a yield of over 98%. Attached Figure Description

[0013] Figure 1 XRD pattern of the molecular sieve catalyst prepared in Example 1;

[0014] Figure 2 A scanning electron microscope image of the molecular sieve catalyst prepared in Example 1;

[0015] Figure 3 The XRD pattern of the molecular sieve catalyst prepared in Example 2;

[0016] Figure 4 A scanning electron microscope image of the molecular sieve catalyst prepared in Example 2;

[0017] Figure 5 The XRD pattern of the molecular sieve catalyst prepared in Example 5;

[0018] Figure 6 A scanning electron microscope image of the molecular sieve catalyst prepared in Example 5;

[0019] Figure 7 XRD pattern of the molecular sieve catalyst prepared in Example 6;

[0020] Figure 8 A scanning electron microscope image of the molecular sieve catalyst prepared in Example 6;

[0021] Figure 9 XRD pattern of the molecular sieve catalyst prepared in Example 9;

[0022] Figure 10 Scanning electron microscope image of the molecular sieve catalyst prepared in Example 9;

[0023] Figure 11 The XRD pattern of the molecular sieve catalyst prepared in Example 12;

[0024] Figure 12 The XRD pattern of the molecular sieve catalyst prepared for Comparative Example 3 is shown. Detailed Implementation

[0025] The endpoints and any values ​​of the ranges disclosed herein 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 herein.

[0026] This invention provides a method for preparing bridged tetrahydrodicyclopentadiene, the method comprising: isomerizing bridged tetrahydrodicyclopentadiene dissolved in an organic solvent under a hydrogen atmosphere and under the conditions of MWW molecular sieve catalyst.

[0027] Main reaction:

[0028]

[0029] The aluminum content at the T2 site of the framework semi-supercage in the MWW molecular sieve catalyst is 10-15 wt% of the total aluminum content, for example, it can be 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, or 15 wt%.

[0030] This invention significantly improves the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction of bridged tetrahydrodicyclopentadiene by using MWW molecular sieve catalyst and controlling the aluminum content at the T2 site of the framework semi-supercage in the molecular sieve to be 10-15 wt% of the total aluminum content.

[0031] According to a preferred embodiment of the present invention, the ratio of strong acid to weak acid in the MWW molecular sieve catalyst is 0.4-0.8. By adopting the aforementioned scheme, the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction of bridged tetrahydrodicyclopentadiene can be further improved.

[0032] According to a preferred embodiment of the present invention, the MWW molecular sieve catalyst has a weak acid content of not less than 490 μmol / g and a strong acid content of not more than 555 μmol / g.

[0033] In this invention, to further improve the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction based on bridged tetrahydrodicyclopentadiene, according to a preferred embodiment of the invention, the weak acid content of the MWW molecular sieve catalyst is 490-1000 μmol / g; and the strong acid content of the MWW molecular sieve is 350-555 μmol / g. By adopting the aforementioned preferred embodiment, the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction based on bridged tetrahydrodicyclopentadiene can be further improved.

[0034] In this invention, there is no particular limitation on the specific surface area of ​​the molecular sieve as long as the objective of the invention can be achieved. According to a preferred embodiment of the invention, the specific surface area of ​​the MWW molecular sieve catalyst is 400-650 m². 2 / g, preferably 450-600m 2 / g, for example, could be 450m 2 / g、500m 2 / g、550m 2 / g、600m 2 / g. By adopting the aforementioned preferred method, the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction of bridged tetrahydrodicyclopentadiene can be further improved.

[0035] According to a preferred embodiment of the present invention, the silicon-to-aluminum ratio of the MWW molecular sieve catalyst is not less than 20, preferably 20-35, based on the SiO2:Al2O3 molar ratio.

[0036] In this invention, the MWW molecular sieve catalyst has a nanosheet morphology with a thickness not exceeding 20 nm, preferably 10-20 nm, and a length not exceeding 800 nm, preferably 200-800 nm. Molecular sieves with this morphology can further improve the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction of bridged tetrahydrodicyclopentadiene.

[0037] In this invention, molecular sieve catalysts possessing the aforementioned characteristics can achieve the objectives of this invention. According to a preferred embodiment of this invention, the MWW molecular sieve catalyst is at least one of SCM-1 molecular sieve catalyst, MCM-22 molecular sieve catalyst, and MCM-49 molecular sieve catalyst. By employing the aforementioned preferred method, the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction of bridged tetrahydrodicyclopentadiene can be further improved.

[0038] According to a preferred embodiment of the present invention, the preparation of the MWW molecular sieve catalyst can be a conventional method in the art. According to the present invention, the preparation method of the MWW molecular sieve catalyst includes:

[0039] A mixture is prepared by mixing a silicon source, an aluminum source, sodium hydroxide, N,N,N-trimethyladamantane ammonium solution, cyclohexylamine, and water. The mixture is then subjected to crystallization, filtration, washing, first drying, first calcination, ammonium exchange, second drying, and second calcination.

[0040] In the mixture, the molar ratio of silicon source (SiO2), aluminum source (Al2O3), sodium hydroxide, N,N,N-trimethyladamantane ammonium solution (N,N,N-trimethyladamantane ammonium), cyclohexylamine, and water is SiO2:Al2O3:NaOH:N,N,N-trimethyladamantane ammonium:cyclohexylamine:H2O = 1:0.028-0.052:0.08-0.20:0.033-0.058:0.025-0.08:12-50.

[0041] In this invention, the N,N,N-trimethyladamantane ammonium solution is an aqueous solution of N,N,N-trimethyladamantane ammonium. As long as the objective of this invention can be achieved, the concentration of the N,N,N-trimethyladamantane ammonium aqueous solution is not particularly required. According to a preferred embodiment of this invention, the concentration of the N,N,N-trimethyladamantane ammonium aqueous solution is 10-40% by weight. This invention uses a concentration of 25.12% by weight of the N,N,N-trimethyladamantane ammonium aqueous solution to illustrate the advantages of this invention.

[0042] In this invention, the silicon source can be a conventional choice in the art. According to a preferred embodiment of the invention, the silicon source is an organosilicon source and / or an inorganic silicon source, preferably at least one of polysilicic acid, fumed silica, tetraethyl orthosilicate, and silica sol.

[0043] In this invention, the aluminum source can be a conventional choice in the art. According to a preferred embodiment of the invention, the aluminum source is an organic aluminum salt and / or an inorganic aluminum salt, preferably at least one of boehmite, aluminum hydroxide, aluminum isopropoxide, and sodium aluminate.

[0044] By adopting the preferred schemes of the above components, the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction of bridged tetrahydrodicyclopentadiene can be further improved.

[0045] In this invention, the crystallization conditions include: a crystallization temperature of 130-180℃, preferably 140-170℃; and a crystallization time of 0.5-4.0 days, preferably 0.75-3.0 days.

[0046] Furthermore, the crystallization method is dynamic crystallization by rotation or stirring, with a rotation or stirring speed of 10-300 rpm, preferably 10-100 rpm.

[0047] Furthermore, no seed crystals need to be added during the crystallization process.

[0048] By adopting the aforementioned preferred scheme, the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction of bridged tetrahydrodicyclopentadiene can be further improved.

[0049] In this invention, the conditions for the first drying can be conventionally chosen in the art. According to a preferred embodiment of the invention, the conditions for the first drying include: a first drying temperature of 70℃-120℃ and a first drying time of 8h-16h. This drying can be carried out under normal pressure or under reduced pressure.

[0050] In this invention, the conditions for the first calcination can be conventionally chosen in the art. According to a preferred embodiment of this invention, the conditions for the first calcination include: a first calcination temperature of 350℃-650℃ and a first calcination time of 3h-6h. This invention uses a first calcination temperature of 550℃ and a first calcination time of 6h to illustrate the advantages of this invention. Furthermore, the calcination is carried out in an oxygen-containing atmosphere.

[0051] In this invention, the ammonium exchange conditions can be conventionally chosen in the art. According to a preferred embodiment of the invention, the ammonium exchange conditions include: a mass ratio of the molecular sieve catalyst obtained after the first calcination to the ammonium solution of 1:5-20, an ammonium exchange temperature of 20-60°C, an ammonium exchange time of 0.5-6 h, and at least one ammonium exchange. This invention uses a mass ratio of the molecular sieve catalyst obtained after the first calcination to the ammonium solution of 1:20, an ammonium exchange temperature of 45°C, an ammonium exchange time of 2 h, and two ammonium exchanges to illustrate the advantages of this invention.

[0052] In this invention, the ammonium salt used in the ammonium exchange solution is selected from at least one of ammonium chloride, ammonium nitrate, ammonium carbonate, and ammonium sulfate. There is no particular limitation on the concentration of ammonium ions in the ammonium salt solution. According to a preferred embodiment of this invention, the concentration of ammonium ions in the ammonium salt solution is 0.1-1 mol / L, preferably 0.1-0.3 mol / L. This invention uses an NH4NO3 solution with an ammonium ion concentration of 0.2 mol / L to illustrate the advantages of this invention.

[0053] In this invention, the conditions for the second drying can be conventional choices in the art. According to a preferred embodiment of the invention, the conditions for the second drying include: a second drying temperature of 60-120°C and a second drying time of 4-24 hours.

[0054] In this invention, the conditions for the second calcination can be conventionally chosen in the art. According to a preferred embodiment of this invention, the conditions for the second calcination include: a second calcination temperature of 400-650°C and a second calcination time of 1-12 hours. This invention illustrates the advantages of the invention by using a second calcination temperature of 550°C and a second calcination time of 6 hours. Furthermore, the calcination is carried out in an oxygen-containing atmosphere.

[0055] In this invention, the oxygen-containing atmosphere is an atmosphere containing oxygen, preferably an atmosphere with an oxygen concentration of 10%-40% by volume, and more preferably air.

[0056] By adopting the preferred schemes of the above conditions, the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction of bridged tetrahydrodicyclopentadiene can be further improved.

[0057] In this invention, the organic solvent can be any conventional choice in the art, as long as it achieves the objective of the invention. According to a preferred embodiment of the invention, the organic solvent comprises cycloalkanes and / or alkyl-substituted derivatives of cycloalkanes, preferably C5-C8 cycloalkanes and / or C1-C3 alkyl-substituted derivatives of C5-C8 cycloalkanes. By adopting the aforementioned preferred embodiment, the selectivity and yield of hanging tetrahydrodicyclopentadiene in the isomerization reaction of bridged tetrahydrodicyclopentadiene can be further improved.

[0058] In this invention, the organic solvent comprises at least one selected from cyclohexane, methylcyclohexane, ethylcyclohexane, diethylcyclohexane, and methylethylcyclohexane.

[0059] The isomerization reaction conditions described in this invention can be conventional conditions, and this invention has no special requirements for them. Specifically, the isomerization reaction conditions include: a reaction temperature of 120℃-200℃, a reaction pressure of 0.5MPa-2.5MPa, and a reaction time of 1h-7h; preferably, the reaction temperature is 150℃-200℃, the reaction pressure is 0.5MPa-2MPa, and the reaction time is 1h-5h. By adopting the aforementioned preferred scheme, the selectivity and yield of the hanging tetrahydrodicyclopentadiene in the isomerization reaction of the bridged tetrahydrodicyclopentadiene can be further improved.

[0060] The present invention will be described in detail below through examples. In the following examples, the specific conditions not specified in the examples are performed according to conventional conditions or conditions recommended by the manufacturer; the reagents or instruments used, unless otherwise specified by the manufacturer, are all conventional products that can be obtained through commercial channels.

[0061] In the context of this specification, the structure of the molecular sieve is determined by X-ray diffraction (XRD), which is measured using an X-ray powder diffractometer with a Cu-Kα ray source and a nickel filter. Before sample testing, the crystallinity of the molecular sieve sample is observed using a scanning electron microscope (SEM) to confirm that the sample contains only one type of crystal, i.e., the molecular sieve sample is a pure phase. XRD testing is then performed to ensure that there are no interfering peaks from other crystals in the diffraction pattern.

[0062] In the context of this specification, including in the following examples and comparative examples, the X-ray powder diffractometer used for the molecular sieves is a Panalytical X-PERPRO type X-ray powder diffractometer, used to analyze the phase composition of the samples, and a CuKα ray source. Nickel filter, 2θ scanning range 2-50°, operating voltage 40KV, current 40mA, scanning rate 10° / min.

[0063] In the context of this specification, including in the following examples and comparative examples, the scanning electron microscope (SEM) used for the molecular sieves is an S-4800II field emission scanning electron microscope. The molecular sieves were observed using this SEM at a magnification of 40,000x. A random field of view was selected, and the average sum of the crystal sizes in that field of view was calculated. This operation was repeated a total of 10 times, and the average sum of the 10 averages was taken as the crystal size.

[0064] In the context of this specification, including in the following examples and comparative examples, the specific surface area of ​​the molecular sieve was measured by the nitrogen physical adsorption-desorption method (BET method): the nitrogen physical adsorption-desorption isotherm of the molecular sieve was measured using a Micromeretic ASAP2020M physical adsorption instrument, and then calculated using the BET equation and t-plot equation. The experimental conditions for this molecular sieve were: measurement temperature -196°C; before measurement, the molecular sieve was heat-treated at 550°C in air for 6 hours, and then pretreated in vacuum at 350°C for 4 hours.

[0065] In the context of this specification, including in the following examples and comparative examples, the content of each element in the molecular sieve was determined by inductively coupled plasma atomic emission spectrometry (ICP) using a Varian 725-ES instrument. The analytical sample was dissolved in hydrofluoric acid before testing, and the content was expressed in moles.

[0066] In the context of this specification, including in the following examples and comparative examples, the acid content of the hydrogen-form molecular sieves was determined using NH3-TPD chemisorption-desorption curves (Altamira AMI-3300 instrument). Before testing, the samples were activated at 550°C for 1 hour, ammonia was adsorbed at 100°C for 20 minutes, and then desorbed and detected at 100-600°C. By analyzing the Gaussian peak distribution, the acid content corresponding to desorption temperatures above 300°C was considered the acid content of a strong acid.

[0067] In the context of this specification, including in the following examples and comparative examples, the content of framework aluminum in the molecular sieve is determined by... 27 Measured using an Al NMR spectrometer, model Bruker AvanceⅢ / WB-400. Peaks with chemical shifts in the range of 65-35 ppm correspond to skeletal aluminum. By performing Gaussian peak division, the percentage of the area corresponding to the peak with a chemical shift of around 60 ppm relative to the total peak area represents the aluminum content at the T2 site of the skeletal semi-supercage.

[0068] In the context of this specification, including in the following examples and comparative examples, the selectivity and yield calculation formulas for hanging tetrahydrodicyclopentadiene are as follows:

[0069] exo-THDCPD selectivity = [exo-THDCPD generation amount / (endo-THDCPD addition amount - endo-THDCPD content in product)] × 100%, Equation (1);

[0070] exo-THDCPD yield = (exo-THDCPD production amount / endo-THDCPD addition amount) × 100%, Equation (2).

[0071] In formulas (1) and (2), endo-THDCPD refers to bridged tetrahydrodicyclopentadiene, and exo-THDCPD refers to hanging tetrahydrodicyclopentadiene.

[0072] Example 1

[0073] 1. Catalyst Preparation

[0074] A mixture was prepared by stirring 33.78 g of deionized water, 0.867 g of sodium aluminate (containing 40.5 wt% Al2O3, 30.6 wt% Na2O, with the remainder being water, the same below), 0.366 g of sodium hydroxide, 2.54 g of N,N,N-trimethyladamantane ammonium aqueous solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium), 0.60 g of cyclohexylamine, and 12.94 g of silica sol (containing 40.0 wt% SiO2, with the remainder being water, the same below) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0075] SiO2 / Al2O3 = 25;

[0076] NaOH / SiO2 = 0.20;

[0077] N,N,N-trimethyladamantane ammonium / SiO2 = 0.035;

[0078] Cyclohexylamine / SiO2 = 0.070;

[0079] H2O / SiO2 = 28.

[0080] The mixture was placed in a stainless steel reactor and heated to crystallize at 155℃ with a stirring speed of 30 rpm for 2 days. After crystallization, it was filtered, washed, dried in an oven at 100℃ for 12 hours, and then calcined in air at 550℃ for 6 hours to obtain sodium-type molecular sieve. The sodium-type molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried at 100℃ for 12 hours and then calcined in air at 550℃ for 6 hours to obtain the hydrogen-type MWW molecular sieve product. The XRD pattern of the product is shown below. Figure 1 The image shown is of the SCM-1 molecular sieve. The SEM image of the molecular sieve sample is shown below. Figure 2 As shown, the crystals are in the form of nanosheets, with a thickness of 15 nm and a length of 310 nm. The aluminum content at the T2 sites of the framework semi-supercage in the molecular sieve is 14.5% of the total aluminum content. The specific surface area, measured by the BET method, is 477 m². 2The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 25.3 by inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 1355 μmol / g by NH3-TPD, with a strong acid content of 389 μmol / g, a weak acid content of 966 μmol / g, and a strong acid to weak acid ratio of 0.40.

[0081] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0082] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of cyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 160 °C for 3 hours. The reaction was then completed. The product was analyzed by gas chromatography (using an HP-5 capillary column, 30 m in length). The selectivity for bridged tetrahydrodicyclopentadiene was 100%, and the yield was 98.2%.

[0083] Example 2

[0084] 1. Catalyst Preparation

[0085] A mixture was prepared by stirring 14.74 g of deionized water, 0.986 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.268 g of sodium hydroxide, 3.20 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent a), 0.52 g of cyclohexylamine (organic structure directing agent b), and 15.88 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0086] SiO2 / Al2O3 = 27;

[0087] NaOH / SiO2 = 0.15;

[0088] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.036;

[0089] Cyclohexylamine / SiO2 = 0.050;

[0090] H2O / SiO2 = 14.

[0091] The mixture was placed in a stainless steel reactor and heated to crystallize at 165℃ with a stirring speed of 20 rpm for 1.5 days. After crystallization, the mixture was filtered, washed, dried in an oven at 100℃ for 12 hours, and calcined in air at 550℃ for 6 hours to obtain sodium-form MCM-22 molecular sieve. The sodium-form molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was dried at 100℃ for 12 hours and calcined in air at 550℃ for 6 hours to obtain hydrogen-form MWW molecular sieve sample. The XRD pattern of the product is shown below. Figure 3 The image shown is of MCM-22 molecular sieve; the SEM image is as follows. Figure 4 As shown, the crystals are in the form of nanosheets, with a thickness of 12 nm and a length of 390 nm. The aluminum content at the T2 sites of the framework semi-supercage in the molecular sieve is 14.1% of the total aluminum content. The specific surface area, measured by the BET method, is 521 m². 2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve before calcination was determined to be 27.2 using inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 1275 μmol / g by NH3-TPD, with a strong acid content of 379 μmol / g, a weak acid content of 896 μmol / g, and a strong acid to weak acid ratio of 0.42.

[0092] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0093] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of cyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 160 °C for 3 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 99.8% for bridged tetrahydrodicyclopentadiene and a yield of 98%.

[0094] Example 3

[0095] 1. Catalyst Preparation

[0096] A mixture was prepared by stirring 24.25 g of deionized water, 0.680 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.087 g of sodium hydroxide, 1.73 g of N,N,N-trimethyladamantane ammonium aqueous solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium), 0.42 g of cyclohexylamine, and 8.52 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0097] SiO2 / Al2O3 = 21;

[0098] NaOH / SiO2 = 0.15;

[0099] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.036;

[0100] Cyclohexylamine / SiO2 = 0.074;

[0101] H2O / SiO2 = 30.

[0102] The mixture was placed in a stainless steel reactor and heated to crystallize at 160℃ and 10 rpm for 2.5 days. After crystallization, it was filtered, washed, dried in a 100℃ oven for 12 hours, and then calcined in air at 550℃ for 6 hours to obtain a sodium-type molecular sieve. The sodium-type molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was dried at 100℃ for 12 hours and then calcined in air at 550℃ for 6 hours to obtain the hydrogen-type MWW molecular sieve product. The XRD pattern of the product was obtained. Figure 1 Similarly, this is an SCM-1 molecular sieve. The SEM image of the molecular sieve sample is similar to... Figure 2 Similarly, the crystals are in the form of nanosheets, with a thickness of 15 nm and a length of 460 nm. The aluminum mass content at the T2 sites of the framework semi-supercage in the molecular sieve is 14.7% of the total aluminum mass content. The specific surface area, measured by the BET method, is 457 m². 2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 21.1 by inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 1465 μmol / g by NH3-TPD, with a strong acid content of 486 μmol / g, a weak acid content of 979 μmol / g, and a strong acid content:weak acid content ratio of 0.50.

[0103] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0104] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of methylcyclohexane were added. The reactor was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, the reaction temperature was 160 °C, and the reaction time was 3 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 99.8% for bridged tetrahydrodicyclopentadiene and a yield of 98%.

[0105] Example 4

[0106] 1. Catalyst Preparation

[0107] A mixture was prepared by stirring 23.41 g of deionized water, 0.661 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.141 g of sodium hydroxide, 2.15 g of N,N,N-trimethyladamantane ammonium aqueous solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium), 0.30 g of cyclohexylamine, and 9.07 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0108] SiO2 / Al2O3 = 23;

[0109] NaOH / SiO2 = 0.16;

[0110] N,N,N-trimethyladamantane ammonium / SiO2 = 0.042;

[0111] Cyclohexylamine / SiO2 = 0.050;

[0112] H2O / SiO2 = 28.

[0113] The mixture was placed in a stainless steel reactor and heated to crystallize at 150℃ with a stirring speed of 30 rpm for 3 days. After crystallization, it was filtered, washed, and dried in an oven at 100℃ for 12 hours. The sample was then calcined in air at 550℃ for 6 hours to obtain a sodium-type molecular sieve. The sodium-type molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was then dried at 100℃ for 12 hours and calcined in air at 550℃ for 6 hours to obtain a hydrogen-type MWW molecular sieve sample. The XRD pattern of the product was obtained. Figure 1 Similarly, it is an SCM-1 molecular sieve. The SEM image of the sample is similar to... Figure 2 Similarly, the crystals are in the form of nanosheets, with a thickness of 18 nm and a length of 500 nm. The aluminum content at the T2 sites of the framework semi-supercage in the molecular sieve is 13.4% of the total aluminum content. The specific surface area, measured by the BET method, is 516 m². 2 The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 23.3 by inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 1379 μmol / g by NH3-TPD, with a strong acid content of 540 μmol / g, a weak acid content of 839 μmol / g, and a strong acid to weak acid ratio of 0.64.

[0114] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0115] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of methylethylcyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 160 °C for 3 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 99.6% for bridged tetrahydrodicyclopentadiene and a yield of 97.5%.

[0116] Example 5

[0117] 1. Catalyst Preparation

[0118] A mixture was prepared by stirring 20.78 g of deionized water, 0.905 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.267 g of sodium hydroxide, 3.74 g of N,N,N-trimethyladamantane ammonium aqueous solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium), 0.75 g of cyclohexylamine, and 15.12 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0119] SiO2 / Al2O3 = 28;

[0120] NaOH / SiO2 = 0.15;

[0121] N,N,N-trimethyladamantane ammonium / SiO2 = 0.044;

[0122] Cyclohexylamine / SiO2 = 0.075;

[0123] H2O / SiO2 = 18.

[0124] The mixture was placed in a stainless steel reactor and heated to crystallize at 165℃ with a stirring speed of 50 rpm for 2.5 days. After crystallization, the mixture was filtered, washed, and dried in an oven at 100℃ for 12 hours. The sodium-type molecular sieve was obtained by calcining the sample in air at 550℃ for 6 hours. The sodium-type molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was then dried at 100℃ for 12 hours and calcined in air at 550℃ for 6 hours to obtain the hydrogen-type MWW molecular sieve sample. The XRD pattern of the product is shown below. Figure 5 The image shown is of the SCM-1 molecular sieve. The SEM image of the sample is shown below. Figure 6As shown, the crystals are in the form of nanosheets, with a thickness of 15 nm and a length of 360 nm. The aluminum mass content at the T2 sites of the framework semi-supercage in the molecular sieve is 13.2% of the total aluminum mass content. The specific surface area, measured by the BET method, is 465 m². 2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 28.1 using inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 1244 μmol / g by NH3-TPD, with a strong acid content of 502 μmol / g, a weak acid content of 742 μmol / g, and a strong acid content:weak acid content ratio of 0.68.

[0125] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0126] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of cyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 160 °C for 3 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 99.3% for bridged tetrahydrodicyclopentadiene and a yield of 97.1%.

[0127] Example 6

[0128] 1. Catalyst Preparation

[0129] A mixture was prepared by stirring 26.44 g of deionized water, 0.800 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.313 g of sodium hydroxide, 3.68 g of N,N,N-trimethyladamantane ammonium aqueous solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium), 0.565 g of cyclohexylamine, and 14.32 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0130] SiO2 / Al2O3 = 30;

[0131] NaOH / SiO2 = 0.16;

[0132] N,N,N-trimethyladamantane ammonium / SiO2 = 0.046;

[0133] Cyclohexylamine / SiO2 = 0.059;

[0134] H2O / SiO2 = 22.

[0135] The mixture was placed in a stainless steel reactor and heated to crystallize at 155℃ with a stirring speed of 30 rpm for 3 days. After crystallization, the mixture was filtered, washed, and dried in an oven at 100℃ for 12 hours. The sodium-type molecular sieve was obtained by calcining the sample in air at 550℃ for 6 hours. The sodium-type molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was then dried at 100℃ for 12 hours and calcined in air at 550℃ for 6 hours to obtain the hydrogen-type MWW molecular sieve sample. The XRD pattern of the product is shown below. Figure 7 The image shown is of the SCM-1 molecular sieve. The SEM image of the sample is shown below. Figure 8 As shown, the crystals are in the form of nanosheets, with a thickness of 16 nm and a length of 390 nm. The aluminum content at the T2 sites of the framework semi-supercage in the molecular sieve is 12.5% ​​of the total aluminum content. The specific surface area, measured by the BET method, is 498 m². 2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 29.8 using inductively coupled plasma atomic emission spectrometry (ICP).

[0136] The total acid content of the molecular sieve was determined by NH3-TPD to be 1046 μmol / g, the strong acid content was 437 μmol / g, the weak acid content was 609 μmol / g, and the ratio of strong acid content to weak acid content was 0.72.

[0137] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0138] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of cyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 160 °C for 3 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 99.2% for bridged tetrahydrodicyclopentadiene and a yield of 96.8%.

[0139] Example 7

[0140] 1. Catalyst Preparation

[0141] A mixture was prepared by stirring 13.88 g of deionized water, 0.696 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.239 g of sodium hydroxide, 3.43 g of N,N,N-trimethyladamantane ammonium aqueous solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium), 0.54 g of cyclohexylamine, and 12.47 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0142] SiO2 / Al2O3 = 30;

[0143] NaOH / SiO2 = 0.15;

[0144] N,N,N-trimethyladamantane ammonium / SiO2 = 0.049;

[0145] Cyclohexylamine / SiO2 = 0.065;

[0146] H2O / SiO2 = 16.

[0147] The mixture was placed in a stainless steel reactor and heated to crystallize at 160℃ with a stirring speed of 20 rpm for 2 days. After crystallization, it was filtered, washed, and dried in an oven at 100℃ for 12 hours. The sample was then calcined in air at 550℃ for 6 hours to obtain a sodium-type molecular sieve. The sodium-type molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was then dried at 100℃ for 12 hours and calcined in air at 550℃ for 6 hours to obtain a hydrogen-type MWW molecular sieve sample. The XRD pattern of the product was obtained as shown below. Figure 1 Similarly, it is an SCM-1 molecular sieve. The SEM image of the sample is similar to... Figure 2 Similarly, the crystals are in the form of nanosheets, with a thickness of 17 nm and a length of 680 nm. The aluminum content at the T2 sites of the framework semi-supercage in the molecular sieve is 12.8% of the total aluminum content. The specific surface area, measured by the BET method, is 521 m². 2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 29.6 using inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 1072 μmol / g by NH3-TPD, with a strong acid content of 470 μmol / g, a weak acid content of 602 μmol / g, and a strong acid content:weak acid content ratio of 0.78.

[0148] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0149] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of cyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 150 °C for 4 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 99% for bridged tetrahydrodicyclopentadiene and a yield of 96.5%.

[0150] Example 8

[0151] 1. Catalyst Preparation

[0152] A mixture was prepared by stirring 24.90 g of deionized water, 0.562 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.398 g of sodium hydroxide, 3.25 g of N,N,N-trimethyladamantane ammonium aqueous solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium), 0.52 g of cyclohexylamine, and 11.40 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0153] SiO2 / Al2O3 = 34;

[0154] NaOH / SiO2 = 0.20;

[0155] N,N,N-trimethyladamantane ammonium / SiO2 = 0.051;

[0156] Cyclohexylamine / SiO2 = 0.069;

[0157] H2O / SiO2 = 25.

[0158] The mixture was placed in a stainless steel reactor and heated to crystallize at 165℃ with a stirring speed of 20 rpm for 1.5 days. After crystallization, the mixture was filtered, washed, and dried in an oven at 100℃ for 12 hours. The sodium-form molecular sieve was obtained by calcining the sample in air at 550℃ for 6 hours. The sodium-form molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was then dried at 100℃ for 12 hours and calcined in air at 550℃ for 6 hours to obtain the hydrogen-form MWW molecular sieve sample. The XRD pattern of the product was obtained. Figure 1 Similarly, it is an SCM-1 molecular sieve. The SEM image of the sample is similar to... Figure 2 Similarly, the crystals are in the form of nanosheets, with a thickness of 13 nm and a length of 510 nm. The aluminum content at the T2 sites of the framework semi-supercage in the molecular sieve is 11.6% of the total aluminum content. The specific surface area, measured by the BET method, is 510 m². 2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 33.8 using inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 881 μmol / g by NH3-TPD, with a strong acid content of 382 μmol / g, a weak acid content of 499 μmol / g, and a strong acid content:weak acid content ratio of 0.77.

[0159] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0160] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of cyclohexane were added. The reactor was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 160 °C for 3 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 99% for bridged tetrahydrodicyclopentadiene and a yield of 96%.

[0161] Example 9

[0162] 1. Catalyst Preparation

[0163] A mixture was prepared by stirring 31.90 g of deionized water, 0.727 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.395 g of sodium hydroxide, 4.06 g of N,N,N-trimethyladamantane ammonium aqueous solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium), 0.66 g of cyclohexylamine, and 13.87 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0164] SiO2 / Al2O3 = 32;

[0165] NaOH / SiO2 = 0.18;

[0166] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.053;

[0167] Cyclohexylamine / SiO2 = 0.072;

[0168] H2O / SiO2 = 26.

[0169] The mixture was placed in a stainless steel reactor and heated to crystallize at 170℃ with a stirring speed of 10 rpm for 1.5 days. After crystallization, the mixture was filtered, washed, and dried in an oven at 100℃ for 12 hours. The sodium-type molecular sieve was obtained by calcining the sample in air at 550℃ for 6 hours. The sodium-type molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was then dried at 100℃ for 12 hours and calcined in air at 550℃ for 6 hours to obtain the hydrogen-type MWW molecular sieve sample. The XRD pattern of the product is shown below. Figure 9 The image shown is of the SCM-1 molecular sieve. The SEM image of the sample is shown below. Figure 10 As shown, the crystals are in the form of nanosheets, with a thickness of 15 nm and a length of 530 nm. The aluminum content at the T2 sites of the framework semi-supercage in the molecular sieve is 12.4% of the total aluminum content. The specific surface area measured by the BET method is 492 m².2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 32.2 using inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 1005 μmol / g by NH3-TPD, with a strong acid content of 436 μmol / g, a weak acid content of 569 μmol / g, and a strong acid content:weak acid content ratio of 0.77.

[0170] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0171] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of cyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 150 °C for 4 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 98.6% for bridged tetrahydrodicyclopentadiene and a yield of 95.6%.

[0172] Example 10

[0173] 1. Catalyst Preparation

[0174] A mixture was prepared by stirring 41.98 g of deionized water, 0.820 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.203 g of sodium hydroxide, 2.71 g of N,N,N-trimethyladamantane ammonium aqueous solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium), 0.57 g of cyclohexylamine, and 14.68 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0175] SiO2 / Al2O3 = 20;

[0176] NaOH / SiO2 = 0.13;

[0177] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.033;

[0178] Cyclohexylamine / SiO2 = 0.058;

[0179] H2O / SiO2 = 30.

[0180] The mixture was placed in a stainless steel reactor and heated to crystallize at 160℃ with a stirring speed of 35 rpm for 3 days. After crystallization, it was filtered, washed, dried in an oven at 100℃ for 12 hours, and then calcined in air at 550℃ for 6 hours to obtain a sodium-type molecular sieve. The sodium-type molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was dried at 100℃ for 12 hours and then calcined in air at 550℃ for 6 hours to obtain the hydrogen-type MWW molecular sieve product. The XRD pattern of the product was obtained. Figure 1 Similarly, this is an SCM-1 molecular sieve. The SEM image of the molecular sieve sample is similar to... Figure 2 Similarly, the crystals are in the form of nanosheets, with a thickness of 16 nm and a length of 360 nm. The aluminum mass content at the T2 sites of the framework semi-supercage in the molecular sieve is 14.6% of the total aluminum mass content. The specific surface area, measured by the BET method, is 489 m². 2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 20.5 using inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 1487 μmol / g by NH3-TPD, with a strong acid content of 648 μmol / g, a weak acid content of 839 μmol / g, and a strong acid content:weak acid content ratio of 0.77.

[0181] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0182] Under the same conditions as in Example 1, the composition of the product was analyzed by gas chromatography, with a selectivity of 92.6% for tetrahydrodicyclopentadiene and a yield of 85%.

[0183] Example 11

[0184] 1. Catalyst Preparation

[0185] A mixture was prepared by stirring 22.34 g of deionized water, 0.675 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.223 g of sodium hydroxide, 3.07 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent a), 0.54 g of cyclohexylamine (organic structure directing agent b), and 13.69 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0186] SiO2 / Al2O3 = 34;

[0187] NaOH / SiO2 = 0.13;

[0188] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.040;

[0189] Cyclohexylamine / SiO2 = 0.060;

[0190] H2O / SiO2 = 20.

[0191] The mixture was placed in a stainless steel reactor and heated to crystallize at 160℃ with a stirring speed of 70 rpm for 2.5 days. After crystallization, the mixture was filtered, washed, dried in an oven at 100℃ for 12 hours, and calcined in air at 550℃ for 6 hours to obtain a sodium-type molecular sieve. The sodium-type molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was dried at 100℃ for 12 hours and calcined in air at 550℃ for 6 hours to obtain the hydrogen-type MWW molecular sieve product. The XRD pattern of the product was obtained. Figure 3 Similarly, for MCM-22 molecular sieves, the SEM image of the molecular sieve sample is similar to... Figure 4 Similarly, the crystals are in the form of nanosheets, with a thickness of 14 nm and a length of 350 nm. The aluminum mass content at the T2 sites of the framework semi-supercage in the molecular sieve is 12.2% of the total aluminum mass content. The external specific surface area measured by the BET method is 469 m². 2 / g; the SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 33.7 using inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 822 μmol / g by NH3-TPD, with a strong acid content of 340 μmol / g, a weak acid content of 482 μmol / g, and a strong acid to weak acid ratio of 0.71.

[0192] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0193] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of methylcyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 160 °C for 3 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 90.5% for bridged tetrahydrodicyclopentadiene and a yield of 82%.

[0194] Example 12

[0195] 1. Catalyst Preparation

[0196] A mixture was prepared by stirring 28.1 g of deionized water, 0.742 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.149 g of sodium hydroxide, 2.90 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent a), 0.59 g of cyclohexylamine (organic structure directing agent b), and 13.29 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 3 hours. The final material ratio (molar ratio) was:

[0197] SiO2 / Al2O3 = 30;

[0198] NaOH / SiO2 = 0.12;

[0199] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.039;

[0200] Cyclohexylamine / SiO2 = 0.068;

[0201] H2O / SiO2 = 24.

[0202] The mixture was placed in a stainless steel reactor and heated to crystallize at 165℃ with a stirring speed of 40 rpm for 3 days. After crystallization, the mixture was filtered, washed, and dried in an oven at 100℃ for 12 hours. The sodium-type molecular sieve was obtained by calcining the sample in air at 550℃ for 6 hours. The sodium-type molecular sieve was then subjected to ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours, followed by centrifugation and washing. This ammonium ion exchange was repeated twice. The resulting sample was then dried at 100℃ for 12 hours and calcined in air at 550℃ for 6 hours to obtain the hydrogen-type MWW molecular sieve sample. The XRD pattern of the product is shown below. Figure 11 The image shown is of MCM-22 molecular sieve. The SEM image of the sample is compared with... Figure 4 Similarly, the crystals are in the form of nanosheets, with a thickness of 22 nm and a length of 450 nm. The aluminum content at the T2 sites of the framework semi-supercage in the molecular sieve is 12.6% of the total aluminum content. The specific surface area, measured by the BET method, is 502 m². 2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 29.9 using inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 906 μmol / g by NH3-TPD, with a strong acid content of 364 μmol / g, a weak acid content of 542 μmol / g, and a strong acid content:weak acid content ratio of 0.67.

[0203] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0204] Under the same conditions as in Example 1, the composition of the product was analyzed by gas chromatography, with a selectivity of 91.8% for tetrahydrodicyclopentadiene and a yield of 84%.

[0205] Example 13

[0206] 1. Catalyst Preparation

[0207] Same as Example 1.

[0208] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0209] The conditions were the same as in Example 1, except that the solvent was toluene. The composition of the product was analyzed by gas chromatography, and the selectivity for tetrahydrodicyclopentadiene was 91.1%, with a yield of 87%.

[0210] Example 14

[0211] The preparation method was the same as in Example 1, except that the aluminum content at the T2 site of the semi-supercage in the prepared SCM-1 molecular sieve was 13.0% of the total aluminum content, and the strong acid to weak acid ratio was 1.01. The reaction product was analyzed by gas chromatography, showing a selectivity of 92.3% for tetrahydrodicyclopentadiene and a yield of 85%.

[0212] Comparative Example 1

[0213] 1. Catalyst Preparation

[0214] Same as Example 2, except that the final material ratio (molar ratio) is:

[0215] SiO2 / Al2O3 = 13;

[0216] NaOH / SiO2 = 0.11;

[0217] N,N,N-trimethyladamantane ammonium / SiO2 = 0.012;

[0218] Cyclohexylamine / SiO2 = 0.065;

[0219] H2O / SiO2 = 36.

[0220] Obtain the XRD pattern of the product and Figure 1 Similarly, it is an SCM-1 molecular sieve. The SEM image of the sample is similar to... Figure 2 Similarly, the crystals are in the form of nanosheets, with a thickness of 18 nm and a length of 390 nm. The aluminum mass content at the T2 sites of the framework semi-supercage in the molecular sieve is 15.6% of the total aluminum mass content. The specific surface area, measured by the BET method, is 462 m². 2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 12.5 using inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 1432 μmol / g by NH3-TPD, with a strong acid content of 638 μmol / g, a weak acid content of 794 μmol / g, and a strong acid content:weak acid content ratio of 0.8.

[0221] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0222] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of methylcyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 160 °C for 3 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 62% for bridged tetrahydrodicyclopentadiene and a yield of 55.4%.

[0223] Comparative Example 2

[0224] 1. Catalyst Preparation

[0225] Same as Example 1, except that the final material ratio (molar ratio) is:

[0226] SiO2 / Al2O3 = 46;

[0227] NaOH / SiO2 = 0.13;

[0228] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.073;

[0229] Cyclohexylamine / SiO2 = 0.035;

[0230] H2O / SiO2 = 22.

[0231] Obtain the XRD pattern of the product and Figure 1 Similarly, it is an SCM-1 molecular sieve. The SEM image of the sample is similar to... Figure 2 Similarly, the crystals are in the form of nanosheets, with a thickness of 13 nm and a length of 490 nm. The aluminum content at the T2 sites of the framework semi-supercage in the molecular sieve is 6.2% of the total aluminum content. The specific surface area, measured by the BET method, is 483 m². 2 / g. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 45.6 using inductively coupled plasma atomic emission spectrometry (ICP). The total acid content of the molecular sieve was determined to be 458 μmol / g by NH3-TPD, with a strong acid content of 299 μmol / g, a weak acid content of 229 μmol / g, and a strong acid content:weak acid content ratio of 1.31.

[0232] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0233] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of methylcyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 160 °C for 3 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 51.2% for bridged tetrahydrodicyclopentadiene and a yield of 36.3%.

[0234] Comparative Example 3

[0235] 1. Catalyst Preparation

[0236] The material ratio is the same as in Example 5, except that N,N,N-trimethyladamantane ammonium solution is not added. The final material ratio (molar ratio) is:

[0237] SiO2 / Al2O3 = 28;

[0238] NaOH / SiO2 = 0.15;

[0239] Cyclohexylamine / SiO2 = 0.075;

[0240] H2O / SiO2 = 18.

[0241] The mixture was placed in a stainless steel reactor and heated to crystallize at 165℃ with a stirring speed of 50 rpm for 2.5 days. After crystallization, the mixture was filtered, washed, and dried in an oven at 100℃ for 12 hours. The sample was then calcined in air at 550℃ for 6 hours, followed by ammonium ion exchange with a 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 45℃ for 2 hours. After centrifugation and washing, the ammonium ion exchange was repeated twice. The resulting sample was then dried at 100℃ for 12 hours and calcined in air at 550℃ for 6 hours. The XRD pattern of the product is shown below. Figure 12 As shown, the sample did not crystallize and was an amorphous substance, not a MWW molecular sieve. The total acid content of the molecular sieve was measured by NH3-TPD to be 38 μmol / g, the strong acid content was 11 μmol / g, the weak acid content was 27 μmol / g, and the ratio of strong acid content to weak acid content was 2.5.

[0242] 2. Synthesis reaction of hanging tetrahydrodicyclopentadiene

[0243] In a 100 mL magnetically stirred reactor, 10 g of bridged tetrahydrodicyclopentadiene, 6 g of the aforementioned molecular sieve catalyst, and 30 mL of cyclohexane were added. The mixture was purged three times with 99.99% nitrogen gas. Hydrogen gas was then introduced into the reactor for purging three times, maintaining the pressure inside the reactor at 1.0 MPa. Stirring was initiated, and the reaction temperature was 160 °C for 3 hours. The reaction was then completed. The product was analyzed by gas chromatography, showing a selectivity of 0.8% for bridged tetrahydrodicyclopentadiene and a yield of 0.2%.

[0244] Comparative Example 4

[0245] The synthesis reaction of hanging tetrahydrodicyclopentadiene was the same as in Example 1, except that MCM-22 molecular sieve, purchased from Tianjin Nanhua Catalyst Co., Ltd., was used. The aluminum content at the T2 site of the semi-supercage in the molecular sieve was 6.2% of the total aluminum content. The composition of the reaction product was analyzed by gas chromatography, and the selectivity for hanging tetrahydrodicyclopentadiene was 61.5%, with a yield of 53%.

[0246] A comparison of the data from the above embodiments and comparative examples reveals that the preparation of hanging tetrahydrodicyclopentadiene using the technical solution of the present invention has the advantages of high product selectivity and high yield.

[0247] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing hanging tetrahydrodicyclopentadiene, characterized in that, The preparation method includes: under the conditions of MWW molecular sieve catalyst, isomerization reaction of bridged tetrahydrodicyclopentadiene dissolved in organic solvent under hydrogen atmosphere, wherein the content of aluminum located at the T2 site of the framework semi-supercage in the MWW molecular sieve catalyst is 10-15 wt% of the total aluminum content. The ratio of strong acid content to weak acid content in the MWW molecular sieve catalyst is 0.4-0.8; The organic solvent is a cycloalkanes and / or alkyl-substituted derivatives of cycloalkanes.

2. The preparation method according to claim 1, wherein, The MWW molecular sieve catalyst has a weak acid content of not less than 490 μmol / g and a strong acid content of not more than 555 μmol / g. The specific surface area of ​​the MWW molecular sieve catalyst is 400-650 m². 2 / g; and / or The silicon-to-aluminum ratio of the MWW molecular sieve catalyst, expressed as a SiO2:Al2O3 molar ratio, is not less than 20.

3. The preparation method according to claim 2, wherein, The MWW molecular sieve catalyst has a weak acid content of 490-1000 μmol / g and a strong acid content of 350-555 μmol / g; The specific surface area of ​​the MWW molecular sieve catalyst is 450-600 m². 2 / g; and / or The silicon-to-aluminum ratio of the MWW molecular sieve catalyst is 20-35, calculated as the SiO2:Al2O3 molar ratio.

4. The preparation method according to claim 1, wherein, The MWW molecular sieve catalyst has a nanosheet morphology with a thickness of no more than 20 nm and a length of no more than 800 nm.

5. The preparation method according to claim 1, wherein, The MWW molecular sieve catalyst has a nanosheet morphology with a thickness of 10-20 nm and a length of 200-800 nm.

6. The preparation method according to claim 1, wherein, The MWW molecular sieve catalyst is at least one of SCM-1 molecular sieve catalyst, MCM-22 molecular sieve catalyst and MCM-49 molecular sieve catalyst.

7. The preparation method according to claim 1, wherein, The preparation method of the MWW molecular sieve catalyst includes: A mixture is prepared by mixing a silicon source, an aluminum source, sodium hydroxide, N,N,N-trimethyladamantane ammonium solution, cyclohexylamine, and water. The mixture is then subjected to crystallization, filtration, washing, first drying, first calcination, ammonium exchange, second drying, and second calcination. In the mixture, the molar ratio of silicon source (SiO2), aluminum source (Al2O3), sodium hydroxide, N,N,N-trimethyladamantane ammonium solution (N,N,N-trimethyladamantane ammonium), cyclohexylamine, and water is SiO2:Al2O3:NaOH:N,N,N-trimethyladamantane ammonium:cyclohexylamine:H2O = 1:0.028-0.052:0.08-0.20:0.033-0.058:0.025-0.08:12-50.

8. The preparation method according to claim 7, wherein, The N,N,N-trimethyladamantane ammonium solution is an aqueous solution of N,N,N-trimethyladamantane ammonium with a concentration of 10-40% by weight; and / or The silicon source is an organosilicon source and / or an inorganic silicon source; and / or The aluminum source is an organic aluminum salt and / or an inorganic aluminum salt; and / or The crystallization conditions include: a crystallization temperature of 130-180℃; a crystallization time of 0.5-4.0 days; and / or The crystallization method is dynamic crystallization by rotation or stirring, with a rotation or stirring speed of 10-300 rpm; and / or No seed crystals need to be added during the crystallization process.

9. The preparation method according to claim 8, wherein, The silicon source is at least one of polysilicic acid, fumed silica, tetraethyl orthosilicate, and silica sol; and / or The aluminum source is at least one selected from boehmite, aluminum hydroxide, aluminum isopropoxide, and sodium aluminate; and / or The crystallization conditions include: a crystallization temperature of 140-170℃; a crystallization time of 0.75-3.0 days; and / or The crystallization method is dynamic crystallization by rotation or stirring, with a rotation or stirring speed of 10-100 rpm.

10. The preparation method according to claim 7, wherein, The first drying conditions include: a first drying temperature of 70℃-120℃, and a first drying time of 8h-16h; and / or The conditions for the first calcination include: a first calcination temperature of 350℃-650℃, and a first calcination time of 3h-6h; and / or The ammonium exchange conditions include: a mass ratio of the molecular sieve catalyst obtained after the first calcination to the ammonium solution of 1:5-20; an ammonium exchange temperature of 20-60℃; an ammonium exchange time of 0.5-6 h; and at least one ammonium exchange cycle; and / or The conditions for the second drying include: a second drying temperature of 60-120℃ and a second drying time of 4-24 hours; and / or The conditions for the second roasting include: a second roasting temperature of 400-650℃ and a second roasting time of 1-12 hours.

11. The preparation method according to claim 1, wherein, The organic solvent is a C5-C8 cycloalkanes and / or a C1-C3 alkyl-substituted derivative of a C5-C8 cycloalkanes.

12. The preparation method according to claim 11, wherein, The organic solvent is at least one selected from cyclohexane, methylcyclohexane, ethylcyclohexane, diethylcyclohexane, and methylethylcyclohexane.

13. The preparation method according to any one of claims 1-12, wherein, The conditions for the isomerization reaction include: a reaction temperature of 120℃-200℃, a reaction pressure of 0.5MPa-2.5MPa, and a reaction time of 1h-7h.

14. The preparation method according to claim 13, wherein, The conditions for the isomerization reaction include: a reaction temperature of 150℃-200℃, a reaction pressure of 0.5MPa-2MPa, and a reaction time of 1h-5h.

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