A ZSM-5 molecular sieve, a catalyst for the alkylation of benzene to ethylbenzene, and its preparation and application.

Abstract

This invention discloses a ZSM-5 molecular sieve, a catalyst for the alkylation of benzene to ethylbenzene, and their preparation and application. The ZSM-5 molecular sieve has a b-axis thickness of 30-100 nm and an exposure of 65%-75% of the crystal plane perpendicular to the b-axis direction. The catalyst for the alkylation of benzene to ethylbenzene prepared using the ZSM-5 molecular sieve exhibits high ethylene conversion, high ethyl selectivity in the alkylation product, and low content of the key impurity xylene during the benzene alkylation reaction.

Description

Technical Field

[0001] This invention belongs to the technical field of catalytic chemistry and chemical engineering, and in particular relates to a ZSM-5 molecular sieve, a catalyst for the alkylation of benzene to ethylbenzene, its preparation method and application. Background Technology

[0002] Benzene alkylation products, such as ethylbenzene, are important basic organic raw materials with a wide range of applications and play a vital role in the development of the national economy.

[0003] The feedstock sources for the alkylation of benzene and ethylene to ethylbenzene are widely available. Ethylene can be derived from pure ethylene, dilute ethylene, or ethanol, among which dilute ethylene is the most inexpensive. Currently, dilute ethylene feedstock mainly comes from the tail gas of FCC and DCC plants, with an ethylene mass concentration typically ranging from 10% to 30%. To alleviate the shortage of dilute ethylene feedstock and create greater economic benefits, developing a technology that uses crude ethane cracking gas as a dilute ethylene feedstock and for the alkylation of benzene to ethylbenzene is particularly important.

[0004] However, the high ethylene concentration (over 40%) in crude ethane cracking gas poses significant problems. Since the alkylation of benzene and ethylene is a strongly exothermic reaction, the reaction of benzene with high-concentration dilute ethylene leads to a significant increase in the temperature rise of the alkylation reactor, increasing the probability of side reactions and the rate of coking. This results in a significant increase in the content of xylene, a key impurity, in the ethylbenzene product, and a substantial reduction in catalyst lifespan. The key to the alkylation technology of benzene and crude ethane cracking gas to ethylbenzene is the development of alkylation catalysts with high activity, high selectivity, and high stability. The active component of the catalyst for the gas-phase alkylation of benzene and ethylene to ethylbenzene is generally ZSM-5 molecular sieve.

[0005] CN101993331A discloses a method for producing ethylbenzene by alkylation of pure ethylene or dry gas with benzene. This method employs a fixed-bed reactor loaded with at least one stage of ZSM-5 molecular sieve catalyst I with a SiO2 / Al2O3 molar ratio of 50-150, and at least one stage of ZSM-5 molecular sieve catalyst II with a SiO2 / Al2O3 molar ratio of 160-300. 30%-70% of the pure ethylene or dry gas enters the bed loaded with catalyst I, and the remaining pure ethylene or dry gas enters the bed loaded with catalyst II. 80%-100% of the benzene enters the first stage of the catalyst I bed from the top of the reactor, and the remaining benzene is fed in stages into the subsequent catalyst beds, with the inlet temperature of each catalyst bed and the inlet temperature of the feed stream at the top of the reactor controlled to be no more than ±5℃. This method involves a complex process flow, requires the use of multiple catalysts in a mixed loading process, and demands strict control.

[0006] CN102875316A discloses a method for producing ethylbenzene from dry gas via benzene alkylation. This method uses dry gas and benzene as reactants, where the reactants react with a catalyst to undergo a gas-phase alkylation reaction to produce ethylbenzene. The catalyst used contains the following components by weight percentage: a) 40%-90% ZSM-5 molecular sieve with a crystal diameter of 5-500 nm and a silicon-to-aluminum molar ratio (SiO2 / Al2O3) of 30-400; b) 9%-59% alumina or silica as a binder; c) 0.1%-10% alkaline earth metal oxides and 0.1%-10% rare earth metal oxides. The shaped catalyst is treated with high-temperature steam, then dried and calcined to obtain the finished catalyst. This catalyst was developed for the production of ethylbenzene from dry gas via benzene alkylation with low ethylene concentrations. For ethylene feedstocks with high ethylene concentrations, especially under low benzene-to-ethylene ratio reaction conditions, its activity, selectivity, and stability need further improvement. Summary of the Invention

[0007] This invention provides a ZSM-5 molecular sieve, a catalyst for the alkylation of benzene to ethylbenzene, its preparation method, and its applications. The ZSM-5 molecular sieve of this invention is a novel type. When used as a catalyst for the alkylation of benzene to ethylbenzene, this molecular sieve can improve ethylene conversion, increase the ethyl selectivity in the alkylation product, suppress side reactions, reduce xylene content, and extend the catalyst's lifespan.

[0008] The first aspect of the present invention provides a ZSM-5 molecular sieve, wherein the b-axis thickness of the molecular sieve is 50-100 nm, and the exposure of the crystal plane perpendicular to the b-axis direction is 65%-75%, preferably 69%-71%.

[0009] In the above technical solution, preferably, the initial static water contact angle of the molecular sieve is in the range of 120-160°.

[0010] In the above technical solution, preferably, the infrared spectrum of the molecular sieve is in the range of 680-760 cm⁻¹. -1 Two strong peaks appeared at the location.

[0011] In the above technical solution, the molar ratio of SiO2 to Al2O3 in the ZSM-5 molecular sieve is 100-300.

[0012] In the above technical solution, the illustrative chemical composition of the molecular sieve in its synthetic state, in molar terms, includes: SiO2:nAl2O3:mR2:xR3, where R2 is organic compound II, R3 is organic compound III, n is 0.0033-0.01, m is 0.0015-0.005, and x is 0.005-0.1. The synthetic state of the molecular sieve refers to its uncalcined state. When the molecular sieve exists in its synthetic state, it may also contain a template agent and water. The template agent is one or more of tetrapropylammonium bromide, tetrapropylammonium hydroxide, ethylamine, ethylenediamine, n-propylamine, propylenediamine, n-butylamine, butanediamine, n-hexylamine, hexamethylenediamine, ammonia, hexamethyleneimine, piperidine, and piperazine. The molar ratio of the template agent to SiO2 is 0.05-0.3. The molar ratio of water to SiO2 is 3-20.

[0013] In the above technical solution, the structural formula of organic compound II is as follows: R1-R3 are each independently selected from methoxy, ethoxy, or 3-methoxypropyl, and R4 and R5 are each independently selected from hydrogen, methyl, ethyl, N-aminomethyl, or N-aminoethyl.

[0014] In the above technical solution, the structural formula of organic compound III is as follows: R1-R6 are each independently selected from methyl, ethyl, propyl or phenyl, and the number of phenyl groups in R1-R6 is 1-4.

[0015] A second aspect of this invention provides a method for preparing the aforementioned ZSM-5 molecular sieve, comprising:

[0016] (a) Mix silicon source I, aluminum source I, water, organic matter I and organic matter II to obtain mixture A;

[0017] (b) Mixture A is processed to obtain mixture B;

[0018] (c) Mix mixture B, silicon source II, aluminum source II, water, template agent and organic matter III to obtain mixture C;

[0019] (d) After crystallization, the mixture C is subjected to liquid-solid separation, washing, and drying to obtain the molecular sieve.

[0020] In the above technical solution, preferably, step (a) has one or more of the following features:

[0021] In the above technical solution, preferably, the silicon source I in step (a) is one or more of tetramethyl silicate, tetraethyl silicate, tetrapropyl silicate, tetrabutyl silicate, and tetraphenyl silicate;

[0022] In the above technical solution, preferably, in step (a), aluminum source I is one or more of aluminum sulfate, aluminum isopropoxide, sodium aluminate, and boehmite;

[0023] In the above technical solution, preferably, in step (a) organic compound I is one or more of tetrapropylammonium hydroxide, ethylamine, ethylenediamine, n-butylamine, butanediamine, hexamethyleneimine, and piperidine;

[0024] In the above technical solution, preferably, the structural formula of organic compound II in step (a) is: R1-R3 are each independently selected from methoxy, ethoxy, or 3-methoxypropyl, and R4 and R5 are each independently selected from hydrogen, methyl, ethyl, N-aminomethyl, or N-aminoethyl.

[0025] In the above technical solution, preferably, the molar ratios of silicon source I, aluminum source I, water, organic matter I and organic matter II in step (a) are as follows: silicon source I: aluminum source I: water: organic matter I: organic matter II = 1:(0-0.02):(5-20):(0.1-1):(0.05-0.3), wherein silicon source I and aluminum source I are calculated as SiO2 and Al2O3, respectively.

[0026] In the above technical solution, preferably, the treatment in step (b) is to stir the mixture at 60-130°C for 1-72 hours under sealed conditions.

[0027] In the above technical solution, preferably, step (c) has one or more of the following features:

[0028] In the above technical solution, preferably, the silicon source II in step (c) is one or more of silica sol, silica fume, silica powder, tetramethyl silicate, tetraethyl silicate, tetrapropyl silicate, tetrabutyl silicate, and tetraphenyl silicate.

[0029] In the above technical solution, preferably, the aluminum source II in step (c) is one or more of aluminum nitrate, aluminum chloride, aluminum sulfate, aluminum isopropoxide, sodium aluminate, and boehmite;

[0030] In the above technical solution, preferably, the template agent in step (c) is one or more of tetrapropylammonium bromide, tetrapropylammonium hydroxide, ethylamine, ethylenediamine, n-propylamine, propylenediamine, n-butylamine, butylenediamine, n-hexylamine, hexamethylenediamine, ammonia, hexamethyleneimine, piperidine, and piperazine;

[0031] In the above technical solution, preferably, the structural formula of organic compound III in step (c) is: R1-R6 are each independently selected from methyl, ethyl, propyl or phenyl, and the number of phenyl groups in R1-R6 is 1-4.

[0032] In the above technical solution, preferably, the molar ratios of silicon source II, aluminum source II, water, template agent and organic matter III in step (c) are as follows: silicon source II: aluminum source II: water: template agent: organic matter III = 1:(0.0033-0.01):(8-20):(0.1-0.3):(0.01-0.10), and the ratio of the mass of the mixture B to the total mass of the five substances silicon source II, aluminum source II, water, template agent and organic matter III is (0.05-0.2):1, wherein silicon source II and aluminum source II are calculated as SiO2 and Al2O3, respectively.

[0033] In the above technical solution, preferably, step (d) has one or more of the following features:

[0034] In the above technical solution, preferably, the crystallization conditions in step (d) are crystallization at 110-170°C for 6-72 hours under sealed conditions;

[0035] In the above technical solution, preferably, the liquid-solid separation method in step (d) is filter paper filtration, centrifugation, or plate and frame filtration; the washing conditions are to wash the solid obtained from the liquid-solid separation multiple times with deionized water until the pH value of the washing liquid is 7-8. The drying conditions are drying at 100-200℃ for 5-12 hours.

[0036] A third aspect of the present invention provides a catalyst for the alkylation of benzene to ethylbenzene, the catalyst comprising a ZSM-5 molecular sieve, wherein the ZSM-5 molecular sieve is derived from the molecular sieve provided in the first aspect or a molecular sieve prepared by the method of the second aspect.

[0037] In the above technical solution, the ZSM-5 molecular sieve in the catalyst exists in a calcined state.

[0038] In the above technical solution, the catalyst may optionally include alumina, silicon dioxide, or a mixture thereof, in addition to molecular sieves.

[0039] In the above technical solution, preferably, the molecular sieve catalyst, based on the mass of the catalyst, has a molecular sieve content of 80% or more, preferably 80%-90%, and an alumina content of 20% or less, preferably 10%-20%.

[0040] In the above technical solution, preferably, the micropore volume of the catalyst is 0.13-0.17 cm³. 3 ·g -1 The mesopore volume is 0.50-0.80 cm³. 3 ·g -1 Its mechanical strength is 50-120 N / cm³, and its bulk density is 0.50-0.60 g·cm³. -3 .

[0041] A fourth aspect of this invention provides a method for preparing a catalyst for the alkylation of benzene to ethylbenzene, comprising:

[0042] (e) The catalyst is obtained by mixing at least one molecular sieve from the molecular sieve described in the first aspect and the molecular sieve prepared in the second aspect, alumina and a polymer mixture, forming a mixture, and then drying, calcining, ammonium exchange, steam treatment and acid washing.

[0043] In the above technical solution, preferably, step (e) has one or more of the following features:

[0044] In the above technical solution, preferably, the alumina in step (e) is alumina monohydrate;

[0045] In the above technical solution, preferably, the polymer mixture in step (e) is a mixture of starch and at least one substance selected from hexadecyltrimethylammonium bromide, P123 or F127, wherein the mass ratio of starch to the polymer mixture is 55%-70%.

[0046] In the above technical solution, preferably, the mass ratio of molecular sieve E, alumina and polymer mixture in step (e) is: molecular sieve E: alumina: polymer mixture = 1:(0.1-0.4):(0.03-0.2);

[0047] In the above technical solution, preferably, in step (e), a molding aid, such as at least one of pectinic acid (e.g., dilute nitric acid) and extrusion aid (e.g., guar gum powder), can be added;

[0048] In the above technical solution, preferably, in step (e), the dilute nitric acid is preferably an aqueous solution of nitric acid with a mass concentration of 3%-10%;

[0049] In the above technical solution, preferably, the mass ratio of molecular sieve E, dilute nitric acid, and guar gum powder in step (e) is: molecular sieve E: dilute nitric acid: guar gum powder = 1:(0.5-1.2):(0.01-0.05);

[0050] In the above technical solution, preferably, the molding in step (e) is extrusion molding, followed by drying, calcination, ammonium exchange, steam treatment, and acid washing.

[0051] In the above technical solution, preferably, the molding shape in step (e) is cylindrical, clover-shaped, four-leaf clover-shaped, gear-shaped, etc.; the drying conditions are 100-200℃ for 5-12 hours; the calcination conditions are 500-600℃ for 4-10 hours; the ammonium exchange conditions are to use an ammonium salt solution with a mass concentration of 2%-10% at 20-80℃ for 1-10 hours, and to exchange continuously 2-5 times, wherein the ammonium salt is one of ammonium sulfate, ammonium chloride, ammonium acetate, or ammonium nitrate; the steam treatment conditions are to use a saturated steam atmosphere at 300-450℃ for 4-10 hours; and the pickling conditions are to use an acid solution with a mass concentration of 0.1%-3.0% at 20-80℃ for 1-10 hours, wherein the acid is at least one of hydrochloric acid, sulfuric acid, nitric acid, or oxalic acid.

[0052] The fifth aspect of the present invention provides a catalyst for the alkylation of benzene to ethylbenzene prepared by the method of the fourth aspect.

[0053] In the above technical solution, preferably, the molecular sieve catalyst, based on the mass of the catalyst, has a molecular sieve content of 80% or more, preferably 80%-90%, and an alumina content of 20% or less, preferably 10%-20%.

[0054] In the above technical solution, preferably, the micropore volume of the catalyst is 0.13-0.17 cm³. 3 ·g -1 The mesopore volume is 0.50-0.80 cm³. 3 ·g -1 Its mechanical strength is 50-120 N / cm, and its bulk density is 0.50-0.60 g·cm³. -3 .

[0055] The sixth aspect of the present invention provides a method for producing ethylbenzene by benzene alkylation, wherein the reaction raw materials benzene and ethylene are contacted with the above-mentioned catalyst to generate ethylbenzene.

[0056] In the above technical solution, preferably, the ethylene mass concentration in the ethylene feedstock is 10%-100%.

[0057] In the above technical solution, preferably, the reaction temperature is 320-380℃, the reaction pressure is 0.5-2.6MPa, and the ethylene mass hourly space velocity is 0.2-1.0h. -1 The molar ratio of benzene to ethylene is 4.0-6.0.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] 1. The inventors of this invention have discovered that the b-axis thickness and the exposure of the crystal plane perpendicular to the b-axis direction of ZSM-5 molecular sieve are crucial to the performance of benzene alkylation catalysts. Since the crystal growth process of ZSM-5 molecular sieves follows the Ostwald-ripening and Wulff construction rules, ZSM-5 molecular sieves prepared by conventional methods often exhibit a coffin morphology, making it difficult to control the b-axis thickness and the exposure of the crystal plane perpendicular to the b-axis direction. Further research by the inventors revealed that by introducing organic compound II and organic compound III at different times during the molecular sieve preparation process, the b-axis thickness of the molecular sieve can be effectively controlled to be 50-100 nm, and the exposure of the crystal plane perpendicular to the b-axis direction to be 65%-75%, preferably 69%-71%. This invention provides a novel ZSM-5 molecular sieve. The ZSM-5 molecular sieve of this invention, when used in the benzene alkylation to ethylbenzene reaction, can significantly improve ethylene conversion, suppress side reactions, reduce the content of the key impurity xylene, and extend the catalyst's lifespan, making it particularly suitable for the benzene alkylation to ethylbenzene reaction.

[0060] 2. Due to the introduction of organic compounds II and III, the ZSM-5 molecular sieve of this invention has an initial static water contact angle in the range of 120-160°, and the molecular sieve contains phenyl groups, with an infrared spectrum in the range of 680-760 cm⁻¹. -1 Two strong peaks appear at the point, which can effectively inhibit the condensation of the binder and the silanol groups on the surface of the molecular sieve during the molding process, reduce the pore-blocking effect of the binder, and help improve the overall performance of the catalyst.

[0061] 3. In the preparation process of the catalyst of this invention, not only is a specific molecular sieve used, but a polymer mixture is also added during the molding process, which reduces the blockage of the molecular sieve micropores by the binder. The resulting catalyst has high micropore volume and mesopore volume, as well as suitable mechanical strength and suitable bulk density. In the reaction process, it further improves the diffusion performance of the reactant molecules, which is beneficial to improving the ethylene conversion rate, suppressing side reactions, reducing xylene content, and extending the catalyst life. It is particularly suitable for industrial benzene and high ethylene concentration mixed C2 alkylation reaction equipment to produce ethylbenzene.

[0062] 4. Compared to the tail gas from conventional FCC and DCC units, the ethylene concentration in crude ethane cracking gas is as high as 40% or more. Since the alkylation of benzene and ethylene is a strongly exothermic reaction, the reaction of benzene with high-concentration dilute ethylene leads to a significant increase in the temperature rise of the alkylation reactor, increasing the probability of side reactions and the rate of coking. This results in a significant increase in the xylene content, a key impurity, in the ethylbenzene product, and a substantial shortening of catalyst lifespan. The catalyst of this invention is particularly suitable for preparing ethylbenzene from a mixture of C2 with high ethylene concentrations as feedstock. Under reaction conditions of high ethylene concentration and a low molar ratio of benzene to ethylene, the ethylene conversion rate is greater than 99.8%, the ethyl selectivity in the alkylation product is greater than 99.4%, and the xylene content, a key impurity, is less than 600 ppm.

[0063] 5. The method of the present invention can use high-ethylene-concentration mixed C2 as raw material, which can expand the source of dilute ethylene raw materials, alleviate the shortage of dilute ethylene raw materials, and create more economic benefits. Attached Figure Description

[0064] Figure 1 The XRD pattern of the molecular sieve prepared in Example 1 of this invention;

[0065] Figure 2 SEM image of the molecular sieve prepared in Example 1 of this invention;

[0066] Figure 3 A photograph of the static water initial contact angle of the molecular sieve prepared in Example 1 of this invention;

[0067] Figure 4 The infrared spectrum of the molecular sieve prepared in Example 1 of this invention;

[0068] Figure 5 The XRD pattern of the molecular sieve prepared in Comparative Example 1 of this invention is shown.

[0069] Figure 6 This is a SEM image of the molecular sieve prepared in Comparative Example 1 of this invention. Detailed Implementation

[0070] The present invention will now be described in detail with reference to specific embodiments, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0071] In this invention, the b-axis thickness of the molecular sieve and the exposure of the crystal planes perpendicular to the b-axis direction are obtained by analyzing SEM images. SEM images were obtained using a Hitachi S-4800 cold field emission high-resolution scanning electron microscope. The exposure of the crystal planes perpendicular to the b-axis direction is defined as the proportion of the area of ​​the 010 crystal plane of the ZSM-5 molecular sieve to the total area of ​​all crystal planes.

[0072] In this invention, the micropore volume and mesopore volume are obtained by nitrogen adsorption-desorption test. The nitrogen adsorption-desorption isotherm of the catalyst is tested at liquid nitrogen temperature using a BEL-MAX specific surface area and pore size analyzer manufactured by BELSORP Corporation of Japan. The total pore volume is calculated using the BET equation, and the micropore volume is calculated using the t-plot method. The difference between the total pore volume and the micropore volume is the mesopore volume.

[0073] In this invention, the mechanical strength is obtained using an intelligent particle strength tester. The DLIII type intelligent particle strength tester from Dalian Penghui Technology Development Co., Ltd. is used to test the mechanical strength of the catalyst. The length of the catalyst is 5mm, and it is placed horizontally on the tester. The maximum pressure that the catalyst can withstand when it is crushed is tested. The average value is taken after testing the crushing strength of 20 catalysts.

[0074] In this invention, the XRD pattern of the catalyst was obtained using a Rigaku Ultima IV X-ray powder diffractometer (Japan). The voltage was set to 35 kV, the current to 30 mA, and the scan rate to 1°·min. -1 .

[0075] In this invention, the bulk density of the catalyst is tested using a 1000mL graduated cylinder. The actual weight of the added catalyst (in grams) is divided by the actual volume, and the unit is g·cm³. -3 .

[0076] In this invention, the SiO2 / Al2O3 molar ratio is obtained by ICP testing. A Kontron Model S-35 ICP-AES analyzer is used to perform the ICP test to obtain the silicon-to-aluminum ratio data.

[0077] In this invention, the static water initial contact angle of the molecular sieve is measured using the Chengde Dingsheng JY-82C video contact angle measuring instrument. An appropriate amount of ground powder sample is placed in a tablet press and pressed into a tablet shape, then placed on the contact angle testing platform. Water droplets are added using the automatic titration system of the equipment, test photos are taken, and then the contact angle is measured using the protractor method.

[0078] The molecular sieve structure was characterized using an iS50 infrared spectrometer from Thermo Scientific, USA, with KBr pellets and a wavenumber range of 400-4000 cm⁻¹. -1 .

[0079]

Example 1

[0080] This embodiment is used to synthesize a catalyst for the alkylation of benzene to ethylbenzene. The specific preparation process is as follows:

[0081] 208.3 g of tetraethyl silicate, 3.33 g of aluminum sulfate octadechydrate, 180 g of water, 101.68 g of tetrapropylammonium hydroxide, and 19.13 g of [structure with...] were mixed. Organic compound II (where R1 is a methoxy group, R2 and R3 are ethoxy groups, and R4 and R5 are hydrogen atoms) is mixed evenly to obtain mixture A1, wherein tetraethyl silicate (calculated as SiO2), aluminum sulfate octadecylhydrate (calculated as Al2O3), water, tetrapropylammonium hydroxide, and organic compound II are in a molar ratio of 1:0.005:10:0.5:0.1. Mixture A1 is stirred in a sealed container at 110°C for 36 hours to obtain mixture B1. 26.6 g of mixture B1, 60 g of silica powder, 3.33 g of aluminum sulfate octadecylhydrate, 180 g of water, 9.02 g of ethylamine, and 14.25 g of [structure not specified] are then mixed. The organic compound III (where R1 and R4 are phenyl, and R2, R3, R5, and R6 are methyl) was contacted to obtain mixture C1, wherein the ratio of silicon powder (SiO2), aluminum sulfate octadecade (Al2O3), water, ethylamine, and organic compound III was 1:0.005:10:0.2:0.05 (molar ratio). C1 was crystallized in a sealed container at 150°C for 48 hours to obtain mixture D1. This mixture was then centrifuged to obtain a solid. The solid was washed repeatedly with deionized water until the pH of the washing solution reached 7.5. The washed solid was then dried at 150°C for 10 hours to obtain molecular sieve E1.

[0082] Catalyst F1 was obtained by mixing 50 g of E1, 15 g of alumina monohydrate, 30 g of 5% nitric acid aqueous solution, 1.5 g of guar gum powder, and 5 g of polymer mixture (including 3 g of starch and 2 g of hexadecyltrimethylammonium bromide) and extruding it into a cylindrical shape. Then, the mixture was treated with 150 °C for 8 hours, 550 °C for 6 hours, 5% ammonium sulfate solution at 50 °C for 6 hours, and this process was repeated 4 times. The mixture was then treated with 400 °C for 6 hours in a saturated steam atmosphere and finally with 0.5% hydrochloric acid solution at 40 °C for 5 hours.

[0083] The XRD pattern of molecular sieve E1 is as follows: Figure 1 As shown, it exhibits typical diffraction peaks of ZSM-5 molecular sieve. The SEM image of molecular sieve E1 is shown below. Figure 2 As shown, the b-axis thickness of the molecular sieve is 90 nm, and the exposure of the crystal plane perpendicular to the b-axis direction is 70%. The SiO2 / Al2O3 molar ratio of molecular sieve E1 is 200. The static water initial contact angle test results of molecular sieve E1 are as follows. Figure 3 As shown, the value is 134°. The infrared spectrum of molecular sieve E1 is as follows: Figure 4 As shown, in the range of 680-760cm -1 Two strong peaks appeared at the location.

[0084] The micropore volume of catalyst F1 was determined to be 0.14 cm³. 3 ·g -1 The mesopore volume is 0.64 cm³. 3 ·g -1 Its mechanical strength is 110 N / cm, and its bulk density is 0.54 g·cm³. -3 .

[0085]

Example 2

[0086] This embodiment is used to synthesize a catalyst for the alkylation of benzene to ethylbenzene. The specific preparation process is as follows:

[0087] 152.2 g of tetramethyl silicate, 2.66 g of aluminum sulfate octadecylhydrate, 360 g of water, 73.1 g of n-butylamine, and 70.8 g of [structure not specified] were added. Organic compound II (where R1 and R2 are methoxy groups, R3 is ethoxy group, R4 is N-aminoethyl group, and R5 is a hydrogen atom) is mixed evenly to obtain mixture A2, wherein tetramethyl silicate (calculated as SiO2), aluminum sulfate octadecylhydrate (calculated as Al2O3), water, n-butylamine, and organic compound II are in a molar ratio of 1:0.004:20:1:0.3. Mixture A2 is stirred in a sealed container at 130°C for 1 hour to obtain mixture B2. 101 g of mixture B2, 60 g of silica, 0.408 g of boehmite, 360 g of water, 61 g of tetrapropylammonium hydroxide, and 38.9 g of [structure with...] are then mixed. Organic compound III (where R1-R3 are phenyl and R4-R6 are ethyl) was contacted to obtain mixture C2, wherein the molar ratio of silica (SiO2): boehmite (Al2O3): water: tetrapropylammonium hydroxide: organic compound III was 1:0.004:20:0.3:0.1. C2 was crystallized in a sealed container at 170℃ for 6 hours to obtain mixture D2. This mixture was then centrifuged to obtain a solid. The solid was washed repeatedly with deionized water until the pH of the washing solution reached 7.5. The washed solid was then dried at 200℃ for 5 hours to obtain molecular sieve E2.

[0088] Catalyst F2 was obtained by mixing 50 g of E2, 20 g of alumina monohydrate, 60 g of 3% nitric acid aqueous solution, 2.5 g of guar gum powder, and 10 g of polymer mixture (including 7 g of starch and 3 g of P123) and extruding it into a four-leaf clover shape. Then, the mixture was treated at 200°C for 5 hours, 600°C for 4 hours, 10% ammonium chloride solution at 80°C for 1 hour, and this process was repeated 4 times. Finally, the mixture was treated at 450°C for 4 hours in a saturated steam atmosphere and 3% hydrochloric acid solution at 80°C for 1 hour.

[0089] XRD characterization of molecular sieve E2 revealed typical ZSM-5 molecular sieve diffraction peaks. The b-axis thickness of molecular sieve E2 was 60 nm, and the exposure of the crystal plane perpendicular to the b-axis direction was 71%. The SiO2 / Al2O3 molar ratio of molecular sieve E2 was 250. The initial static water contact angle of molecular sieve E2 was 154°. The infrared spectrum of molecular sieve E2 was in the range of 680-760 cm⁻¹. -1 Two strong peaks appeared at the location.

[0090] The micropore volume of catalyst F2 was determined to be 0.16 cm³. 3 ·g -1 The mesopore volume is 0.81 cm³. 3 ·g -1 Its mechanical strength is 96 N / cm, and its bulk density is 0.51 g·cm³. -3 .

[0091]

Example 3

[0092] This embodiment is used to synthesize a catalyst for the alkylation of benzene to ethylbenzene. The specific preparation process is as follows:

[0093] 208.3 g of tetraethyl silicate, 2.20 g of aluminum sulfate octadechydrate, 90 g of water, 20.34 g of tetrapropylammonium hydroxide, and 16.05 g of [structure with...] were mixed. Organic compound II (where R1 is methoxy, R2 is ethoxy, R3 is 3-methoxypropyl, and R4 and R5 are methyl) is mixed evenly to obtain mixture A3, wherein the molar ratio of tetraethyl silicate (SiO2): aluminum sulfate octadecylhydrate (Al2O3): water: tetrapropylammonium hydroxide: organic compound II is 1:0.0033:5:0.1:0.05. Mixture A3 is stirred in a sealed container at 60°C for 72 hours to obtain mixture B3. 18.23 g of mixture B3, 208.3 g of tetraethyl silicate, 2.20 g of aluminum sulfate octadecylhydrate, 144 g of water, 7.34 g of n-butylamine, and 4.09 g of [structure not specified] are then mixed. The organic compound III (where R1, R2, R4, and R5 are phenyl, and R3 and R6 are methyl) was contacted to obtain mixture C3, wherein tetraethyl silicate (calculated as SiO2), aluminum sulfate octadecade (calculated as Al2O3), and water, n-butylamine, and organic compound III were in a molar ratio of 1:0.0033:8:0.1:0.01. C3 was crystallized in a sealed container at 110°C for 72 hours to obtain mixture D3. This mixture was then centrifuged to obtain a solid, which was washed repeatedly with deionized water until the pH of the washing solution reached 7.5. The washed solid was then dried at 100°C for 12 hours to obtain molecular sieve E3.

[0094] Catalyst F3 was obtained by mixing 50 g of E3, 5 g of alumina monohydrate, 25 g of 3% nitric acid aqueous solution, 0.5 g of guar gum powder, and 1.5 g of polymer mixture (including 0.825 g of starch and 0.675 g of F127) and extruding it into a four-leaf clover shape. Then, the mixture was treated at 100°C for 12 hours, 500°C for 10 hours, 2% ammonium acetate solution at 20°C for 10 hours (repeated four times), 300°C for 10 hours in a saturated steam atmosphere, and 0.1% oxalic acid solution at 20°C for 10 hours.

[0095] XRD characterization of molecular sieve E3 revealed typical ZSM-5 molecular sieve diffraction peaks. The b-axis thickness of molecular sieve E3 was 95 nm, and the exposure of the crystal plane perpendicular to the b-axis direction was 69%. The SiO2 / Al2O3 molar ratio of molecular sieve E3 was 302. The initial static water contact angle of molecular sieve E3 was 121°. The infrared spectrum of molecular sieve E3 was in the range of 680-760 cm⁻¹. -1 Two strong peaks appeared at the location.

[0096] The micropore volume of catalyst F3 was determined to be 0.13 cm³. 3 ·g -1 The mesopore volume is 0.52 cm³. 3 ·g -1 Its mechanical strength is 104 N / cm, and its bulk density is 0.58 g·cm³. -3 .

[0097]

Example 4

[0098] This embodiment is used to synthesize a catalyst for the alkylation of benzene to ethylbenzene. The specific preparation process is as follows:

[0099] 208.3 g of tetraethyl silicate, 180 g of water, 101.68 g of tetrapropylammonium hydroxide, and 19.13 g of [structure with...] were mixed. Organic compound II (where R1 is methoxy, R2 and R3 are ethoxy, and R4 and R5 are hydrogen atoms) is mixed evenly to obtain mixture A4, wherein the molar ratio of tetraethyl silicate (calculated as SiO2): water: tetrapropylammonium hydroxide: organic compound II is 1:10:0.5:0.1. Mixture A4 is stirred in a sealed container at 110°C for 36 hours to obtain mixture B4. 26.6 g of mixture B4, 60 g of silica powder, 3.33 g of aluminum sulfate octadechydrate, 180 g of water, 9.02 g of ethylamine, and 14.25 g of [structure not specified] are then mixed. The organic compound III (where R1 and R4 are phenyl, and R2, R3, R5, and R6 are methyl) was contacted to obtain mixture C4, wherein the ratio of silicon powder (SiO2), aluminum sulfate octadecade (Al2O3), water, ethylamine, and organic compound III was 1:0.005:10:0.2:0.05 (molar ratio). C4 was crystallized in a sealed container at 150°C for 48 hours to obtain mixture D4. This mixture was then centrifuged to obtain a solid. The solid was washed repeatedly with deionized water until the pH of the washing solution reached 7.5. The washed solid was then dried at 150°C for 10 hours to obtain molecular sieve E4.

[0100] Catalyst F4 was obtained by mixing 50 g of E4, 15 g of alumina monohydrate, 30 g of 5% nitric acid aqueous solution, 1.5 g of guar gum powder, and 5 g of polymer mixture (including 3 g of starch and 2 g of hexadecyltrimethylammonium bromide) and extruding it into a cylindrical shape. Then, the mixture was treated with 150 °C for 8 hours, 550 °C for 6 hours, 5% ammonium sulfate solution at 50 °C for 6 hours, and this process was repeated 4 times. The mixture was then treated with 400 °C for 6 hours in a saturated steam atmosphere and finally with 0.5% hydrochloric acid solution at 40 °C for 5 hours.

[0101] XRD characterization of molecular sieve E4 revealed typical diffraction peaks characteristic of ZSM-5 molecular sieves. Molecular sieve E4 has a b-axis thickness of 85 nm and an exposure of 71% of the crystal planes perpendicular to the b-axis. The SiO2 / Al2O3 molar ratio of molecular sieve E4 is 202. The initial static water contact angle of molecular sieve E4 is 133°. The infrared spectrum of molecular sieve E2 is in the range of 680-760 cm⁻¹. -1 Two strong peaks appeared at the location.

[0102] The micropore volume of catalyst F4 was determined to be 0.14 cm³. 3 ·g -1 The mesopore volume is 0.65 cm³. 3 ·g -1 Its mechanical strength is 106 N / cm, and its bulk density is 0.54 g·cm³. -3 .

[0103] Comparative Example 1

[0104] Compared with Example 1, the only difference is that the structural formula is not added. The specific preparation process of the catalyst for organic compound II (where R1 is methoxy, R2 and R3 are ethoxy, and R4 and R5 are hydrogen atoms) is as follows:

[0105] Mixture A5 was prepared by uniformly mixing 208.3 g of tetraethyl silicate, 3.33 g of aluminum sulfate octadechydrate, 180 g of water, and 101.68 g of tetrapropylammonium hydroxide, where the molar ratio of tetraethyl silicate (SiO2), aluminum sulfate octadechydrate (Al2O3), and water to tetrapropylammonium hydroxide was 1:0.005:10:0.5. Mixture A5 was stirred in a sealed container at 110°C for 36 h to obtain mixture B5. Mixture B5 was then prepared by mixing 26.6 g of mixture B5, 60 g of silica powder, 3.33 g of aluminum sulfate octadechydrate, 180 g of water, 9.02 g of ethylamine, and 14.25 g of [structure not specified]. A mixture C5 was obtained by contacting organic compound III (where R1 and R4 are phenyl, and R2, R3, R5, and R6 are methyl) with silicon powder (SiO2), aluminum sulfate octadecade (Al2O3), and water, ethylamine, and organic compound III in a molar ratio of 1:0.005:10:0.2:0.05. C5 was crystallized in a sealed container at 150°C for 48 hours to obtain mixture D5. This mixture was then centrifuged to obtain a solid. The solid was washed repeatedly with deionized water until the pH of the washing solution reached 7.5. The washed solid was then dried at 150°C for 10 hours to obtain molecular sieve E5.

[0106] Catalyst F5 was obtained by mixing 50 g of E5, 15 g of alumina monohydrate, 30 g of 5% nitric acid aqueous solution, 1.5 g of guar gum powder, and 5 g of polymer mixture (including 3 g of starch and 2 g of hexadecyltrimethylammonium bromide) and extruding it into a cylindrical shape. Then, the mixture was treated with 150 °C for 8 hours, 550 °C for 6 hours, 5% ammonium sulfate solution at 50 °C for 6 hours, and this process was repeated 4 times. The mixture was then treated with 400 °C for 6 hours in a saturated steam atmosphere and finally with 0.5% hydrochloric acid solution at 40 °C for 5 hours.

[0107] The XRD pattern of molecular sieve E5 is as follows: Figure 5 As shown, it exhibits typical diffraction peaks of ZSM-5 molecular sieve. The SEM image of molecular sieve E5 is shown below. Figure 6 As shown, the b-axis thickness of the molecular sieve is 160 nm, and the exposure of the crystal plane perpendicular to the b-axis direction is 61%. The SiO2 / Al2O3 molar ratio of molecular sieve E5 is 202. The initial static water contact angle of molecular sieve E5 is 138°. The infrared spectrum of molecular sieve E2 is in the range of 680-760 cm⁻¹. -1 Two strong peaks appeared at the location.

[0108] The micropore volume of catalyst F5 was determined to be 0.13 cm³ through testing. 3 ·g -1 The mesopore volume is 0.58 cm³. 3 ·g -1 Its mechanical strength is 107 N / cm, and its bulk density is 0.55 g·cm³.-3 .

[0109] Comparative Example 2

[0110] Compared with Example 1, the only difference is that the structural formula is not added. The specific preparation process of the catalyst for organic compound III (where R1 and R4 are phenyl, and R2, R3, R5, and R6 are methyl) is as follows:

[0111] 208.3 g of tetraethyl silicate, 3.33 g of aluminum sulfate octadechydrate, 180 g of water, 101.68 g of tetrapropylammonium hydroxide, and 19.13 g of [structure with...] were mixed. Organic compound II (where R1 is methoxy, R2 and R3 are ethoxy, and R4 and R5 are hydrogen atoms) is mixed evenly to obtain mixture A6, wherein the molar ratio of tetraethyl silicate (SiO2): aluminum sulfate octadecylhydrate (Al2O3): water: tetrapropylammonium hydroxide: organic compound II is 1:0.005:10:0.5:0.1. Mixture A6 is stirred in a sealed container at 110°C for 36 hours to obtain mixture B6. 26.6 g of mixture B6, 60 g of silica powder, 3.33 g of aluminum sulfate octadecylhydrate, 180 g of water, and 9.02 g of ethylamine are contacted to obtain mixture C6, wherein the molar ratio of silica powder (SiO2): aluminum sulfate octadecylhydrate (Al2O3): water:ethylamine is 1:0.005:10:0.2. C6 was crystallized in a sealed container at 150°C for 48 hours to obtain mixture D6. The mixture was then centrifuged to obtain a solid. The solid was washed multiple times with deionized water until the pH of the washing solution reached 7.5. The washed solid was then dried at 150°C for 10 hours to obtain molecular sieve E6.

[0112] Catalyst F6 was obtained by mixing 50 g of E6, 15 g of alumina monohydrate, 30 g of 5% nitric acid aqueous solution, 1.5 g of guar gum powder, and 5 g of polymer mixture (including 3 g of starch and 2 g of hexadecyltrimethylammonium bromide) and extruding it into a cylindrical shape. Then, the mixture was treated with 150 °C for 8 hours, 550 °C for 6 hours, 5% ammonium sulfate solution at 50 °C for 6 hours, and this process was repeated 4 times. The mixture was then treated with 400 °C for 6 hours in a saturated steam atmosphere and finally with 0.5% hydrochloric acid solution at 40 °C for 5 hours.

[0113] XRD characterization of molecular sieve E6 revealed typical diffraction peaks characteristic of ZSM-5 molecular sieves. The b-axis thickness of molecular sieve E6 is 185 nm, with 61% exposure of the crystal plane perpendicular to the b-axis. The SiO2 / Al2O3 molar ratio of molecular sieve E6 is 20:1. The initial static water contact angle of molecular sieve E6 is 43°. The infrared spectrum of molecular sieve E6 is in the range of 680-760 cm⁻¹. -1 No two strong peaks were observed.

[0114] The micropore volume of catalyst F6 was determined to be 0.13 cm³. 3 ·g -1 The mesopore volume is 0.58 cm³. 3 ·g -1 Its mechanical strength is 110 N / cm, and its bulk density is 0.55 g·cm³. -3 .

[0115] Comparative Example 3

[0116] Compared with Example 1, the only difference is that organic compound II and organic compound III are added at the same time.

[0117] Mixture A7 was prepared by uniformly mixing 208.3 g of tetraethyl silicate, 3.33 g of aluminum sulfate octadechydrate, 180 g of water, and 101.68 g of tetrapropylammonium hydroxide, where the molar ratio of tetraethyl silicate (SiO2), aluminum sulfate octadechydrate (Al2O3), and water to tetrapropylammonium hydroxide was 1:0.005:10:0.5. Mixture A7 was stirred in a sealed container at 110°C for 36 h to obtain mixture B7. Mixture B7 was prepared by mixing 26.6 g of mixture B7, 60 g of silicon powder, 3.33 g of aluminum sulfate octadechydrate, 180 g of water, 9.02 g of ethylamine, and 0.995 g of [structure not specified]. Organic compound II (where R1 is a methoxy group, R2 and R3 are ethoxy groups, and R4 and R5 are hydrogen atoms) and 14.25 grams of the structure are as follows: (Where R1 and R4 are phenyl, and R2, R3, R5, and R6 are methyl) Organic compound III was contacted to obtain mixture C7, wherein the ratio of silicon powder (SiO2): aluminum sulfate octadecade (Al2O3): water: ethylamine: organic compound III = 1:0.005:10:0.2:0.05 (molar ratio). C7 was crystallized in a sealed container at 150°C for 48 hours to obtain mixture D7. The mixture was then centrifuged to obtain a solid, which was washed repeatedly with deionized water until the pH of the washing solution reached 7.5. The washed solid was then dried at 150°C for 10 hours to obtain molecular sieve E7.

[0118] Catalyst F7 was obtained by mixing 50 g of E7, 15 g of alumina monohydrate, 30 g of 5% nitric acid aqueous solution, 1.5 g of guar gum powder, and 5 g of polymer mixture (including 3 g of starch and 2 g of hexadecyltrimethylammonium bromide) and extruding it into a cylindrical shape. Then, the mixture was treated with 150 °C for 8 hours, 550 °C for 6 hours, 5% ammonium sulfate solution at 50 °C for 6 hours, and this process was repeated 4 times. The mixture was then treated with 400 °C for 6 hours in a saturated steam atmosphere and finally with 0.5% hydrochloric acid solution at 40 °C for 5 hours.

[0119] Molecular sieve E7 exhibits typical ZSM-5 molecular sieve diffraction peaks as characterized by XRD. The b-axis thickness of molecular sieve E7 is 155 nm, and the exposure of the crystal plane perpendicular to the b-axis direction is 62%. The SiO2 / Al2O3 molar ratio of molecular sieve E7 is 20:2. The initial static water contact angle of molecular sieve E7 is 140°. The infrared spectrum of molecular sieve E7 is in the range of 680-760 cm⁻¹. -1 Two strong peaks appeared at the location.

[0120] The micropore volume of catalyst F7 was determined to be 0.13 cm³. 3 ·g -1 The mesopore volume is 0.60 cm³. 3 ·g -1 Its mechanical strength is 103 N / cm, and its bulk density is 0.55 g·cm³. -3 .

[0121] Comparative Example 4

[0122] Compared with Example 1, the only difference is that an equimolar structural formula is used. The organic compound II with the substitutional structural formula (where R1 is methoxy, R2 and R3 are ethoxy, and R4 and R5 are hydrogen atoms) is: Organic compound III (where R1 and R4 are phenyl, and R2, R3, R5 and R6 are methyl).

[0123] 208.3 g of tetraethyl silicate, 3.33 g of aluminum sulfate octadechydrate, 180 g of water, 101.68 g of tetrapropylammonium hydroxide, and 19.13 g of [structure with...] were mixed. Organic compound II (where R1 is a methoxy group, R2 and R3 are ethoxy groups, and R4 and R5 are hydrogen atoms) is mixed evenly to obtain mixture A8, wherein tetraethyl silicate (calculated as SiO2), aluminum sulfate octadecylhydrate (calculated as Al2O3), water, tetrapropylammonium hydroxide, and organic compound II are in a molar ratio of 1:0.005:10:0.5:0.1. Mixture A8 is stirred in a sealed container at 110°C for 36 hours to obtain mixture B8. 26.6 g of mixture B8, 60 g of silica powder, 3.33 g of aluminum sulfate octadecylhydrate, 180 g of water, 9.02 g of ethylamine, and 9.57 g of [structure not specified] are then mixed. A mixture C8 was obtained by contacting organic compound II (where R1 is methoxy, R2 and R3 are ethoxy, and R4 and R5 are hydrogen atoms), wherein the molar ratio of silicon powder (SiO2), aluminum sulfate octadecade (Al2O3), water, ethylamine, and organic compound II was 1:0.005:10:0.2:0.05. C8 was crystallized in a sealed container at 150°C for 48 hours to obtain mixture D8. This mixture was then centrifuged to obtain a solid. The solid was washed repeatedly with deionized water until the pH of the washing solution reached 7.5. The washed solid was then dried at 150°C for 10 hours to obtain molecular sieve E8.

[0124] Catalyst F8 was obtained by mixing 50 g of E8, 15 g of alumina monohydrate, 30 g of 5% nitric acid aqueous solution, 1.5 g of guar gum powder, and 5 g of polymer mixture (including 3 g of starch and 2 g of hexadecyltrimethylammonium bromide) and extruding it into a cylindrical shape. Then, the mixture was treated with 150 °C for 8 hours, 550 °C for 6 hours, 5% ammonium sulfate solution at 50 °C for 6 hours, and this process was repeated 4 times. The mixture was then treated with 400 °C for 6 hours in a saturated steam atmosphere and finally with 0.5% hydrochloric acid solution at 40 °C for 5 hours.

[0125] XRD characterization of molecular sieve E8 revealed typical diffraction peaks characteristic of ZSM-5 molecular sieves. The b-axis thickness of molecular sieve E8 is 146 nm, with 62% exposure of the crystal plane perpendicular to the b-axis. The SiO2 / Al2O3 molar ratio of molecular sieve E8 is 20:1. The initial static water contact angle of molecular sieve E8 is 82°. The infrared spectrum of molecular sieve E8 is located in the range of 680-760 cm⁻¹. -1 No two strong peaks were observed.

[0126] The micropore volume of catalyst F8 was determined to be 0.14 cm³. 3 ·g -1 The mesopore volume is 0.61 cm³. 3 ·g -1 Its mechanical strength is 102 N / cm, and its bulk density is 0.55 g·cm³. -3 .

[0127] Comparative Example 5

[0128] Compared with Example 1, the only difference is that an equimolar structural formula is used. The organic compound III substitution structure (where R1 and R4 are phenyl, and R2, R3, R5, and R6 are methyl) is: Organic compound II (where R1 is methoxy, R2 and R3 are ethoxy, and R4 and R5 are hydrogen atoms).

[0129] 208.3 g of tetraethyl silicate, 3.33 g of aluminum sulfate octadechydrate, 180 g of water, 101.68 g of tetrapropylammonium hydroxide, and 28.5 g of [structure not specified] were mixed. Organic compound III (where R1 and R4 are phenyl, and R2, R3, R5, and R6 are methyl) is mixed evenly to obtain mixture A9, wherein tetraethyl silicate (calculated as SiO2), aluminum sulfate octadecylhydrate (calculated as Al2O3), water, tetrapropylammonium hydroxide, and organic compound III are in a molar ratio of 1:0.005:10:0.5:0.1. Mixture A9 is stirred in a sealed container at 110°C for 36 hours to obtain mixture B9. 26.6 g of mixture B9, 60 g of silica powder, 3.33 g of aluminum sulfate octadecylhydrate, 180 g of water, 9.02 g of ethylamine, and 14.25 g of [structure not specified] are then mixed. A mixture C9 was obtained by contacting organic compound III (where R1 and R4 are phenyl, and R2, R3, R5, and R6 are methyl) with silicon powder (SiO2), aluminum sulfate octadecade (Al2O3), and water, ethylamine, and organic compound III in a molar ratio of 1:0.005:10:0.2:0.05. C9 was crystallized in a sealed container at 150°C for 48 hours to obtain mixture D9. This mixture was then centrifuged to obtain a solid, which was washed repeatedly with deionized water until the pH of the washing solution reached 7.5. The washed solid was then dried at 150°C for 10 hours to obtain molecular sieve E9.

[0130] Catalyst F9 was obtained by mixing 50 g of E9, 15 g of alumina monohydrate, 30 g of 5% nitric acid aqueous solution, 1.5 g of guar gum powder, and 5 g of polymer mixture (including 3 g of starch and 2 g of hexadecyltrimethylammonium bromide) and extruding it into a cylindrical shape. Then, the mixture was treated with 150 °C for 8 hours, 550 °C for 6 hours, 5% ammonium sulfate solution at 50 °C for 6 hours, and this process was repeated 4 times. The mixture was then treated with 400 °C for 6 hours in a saturated steam atmosphere and finally with 0.5% hydrochloric acid solution at 40 °C for 5 hours.

[0131] Molecular sieve E9 exhibits typical ZSM-5 molecular sieve diffraction peaks as characterized by XRD. The b-axis thickness of molecular sieve E9 is 150 nm, and the exposure of the crystal plane perpendicular to the b-axis direction is 62%. The SiO2 / Al2O3 molar ratio of molecular sieve E9 is 20:1. The initial static water contact angle of molecular sieve E9 is 152°. The infrared spectrum of molecular sieve E9 is in the range of 680-760 cm⁻¹. -1 Two strong peaks appeared at the location.

[0132] The micropore volume of catalyst F9 was determined to be 0.13 cm³. 3 ·g -1 The mesopore volume is 0.61 cm³. 3 ·g -1 Its mechanical strength is 106 N / cm, and its bulk density is 0.55 g·cm³. -3 .

[0133]

Examples 5-8

[0134] Catalysts F1-F4 prepared in Examples 1-4 were applied to the benzene alkylation reaction to ethylbenzene, wherein the ethylene mass concentration was 50%, the reaction temperature was 340°C, the pressure was 2.2 MPa, and the ethylene mass hourly space velocity was 0.8 h⁻¹. -1 Under the condition of a benzene to ethylene molar ratio of 4.5, the ethylene conversion rate, ethyl selectivity in the alkylation product, and the content of the key impurity xylene were tested. The test results are shown in Table 1 below.

[0135] Comparative Examples 6-10

[0136] Catalysts F5-F9 prepared in Comparative Examples 1-5 were applied to the benzene alkylation reaction to ethylbenzene, with an ethylene mass concentration of 50%, a reaction temperature of 340℃, a pressure of 2.2 MPa, and an ethylene mass hourly space velocity of 0.8 h⁻¹. -1 Under the condition of a benzene to ethylene molar ratio of 4.5, the ethylene conversion rate, ethyl selectivity in the alkylation product, and the content of the key impurity xylene were tested. The test results are shown in Table 1 below.

[0137] Table 1 Results of the phenylalkylation reaction to produce ethylbenzene

[0138]

[0139]

Examples 9-12

[0140] The catalysts F1-F4 prepared in Examples 1-4 were tested for their single-pass lifetime in the benzene alkylation to ethylbenzene reaction under ultra-high ethylene space velocity (UHSV) conditions, wherein the ethylene mass concentration was 50%, the reaction temperature was 340°C, the pressure was 2.2 MPa, and the ethylene mass space velocity was 10 h⁻¹. -1 The test was conducted under the condition that the molar ratio of benzene to ethylene was 4.5. The single-pass life refers to the time elapsed from the start of the reaction until the ethylene conversion rate drops to 40% of the initial conversion rate. The test results are shown in Table 2 below.

[0141] Comparative Examples 11-15

[0142] Catalysts F5-F9 prepared in comparative examples 1-5 were tested under ultra-high ethylene space velocity (ESV) reaction conditions in the benzene alkylation to ethylbenzene reaction. The ethylene mass concentration was 50%, the reaction temperature was 340℃, the pressure was 2.2 MPa, and the ethylene mass space velocity was 10 h⁻¹. -1 The test was conducted under the condition that the molar ratio of benzene to ethylene was 4.5. The single-pass lifetime refers to the time elapsed from the start of the reaction until the ethylene conversion rate drops to 40% of the initial conversion rate. The test results are shown in Table 2 below. Under the reaction conditions of ultra-high ethylene space velocity, the single-pass lifetime of catalysts F1-F4 is significantly longer than that of catalysts F5-F9.

[0143] Table 2. Single-pass lifetime test results of catalysts under ultra-high space velocity reaction conditions.

[0144] Catalyst number Single-trip lifespan, h F1 388 F2 372 F3 366 F4 382 F5 243 F6 258 F7 246 F8 243 F9 258

[0145] The specific 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 combining the 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 ZSM-5 molecular sieve, characterized in that, In the molecular sieve, the b-axis thickness is 30-100 nm, and the exposure of the crystal plane perpendicular to the b-axis direction is 65%-75%; the initial static water contact angle of the molecular sieve is in the range of 120-160°; the infrared spectrum of the molecular sieve is in the range of 680-760 cm⁻¹. -1 Two strong peaks appeared at the location.

2. The molecular sieve according to claim 1, characterized in that, In the molecular sieve, the b-axis thickness is 50-90 nm, and the exposure of the crystal plane perpendicular to the b-axis direction is 69%-71%.

3. The molecular sieve according to claim 1, characterized in that, The SiO2 / Al2O3 molar ratio of the molecular sieve is 100-300.

4. A method for preparing the ZSM-5 molecular sieve according to any one of claims 1-3, comprising: (a) Mix silicon source I, optional aluminum source I, water, organic compound I and organic compound II to obtain mixture A; (b) Mixture A is processed to obtain mixture B; (c) Mix mixture B, silicon source II, aluminum source II, water, template agent and organic matter III to obtain mixture C; (d) After crystallization, the mixture C is subjected to liquid-solid separation, washing, and drying to obtain the molecular sieve; The structural formula of organic compound II in step (a) is: R1-R3 are each independently selected from methoxy, ethoxy or 3-methoxypropyl, and R4 and R5 are each independently selected from hydrogen atom, methyl, ethyl, N-aminomethyl or N-aminoethyl; The structural formula of organic compound III in step (c) is: R1-R6 are each independently selected from methyl, ethyl, propyl or phenyl, and the number of phenyl groups in R1-R6 is 1-4. In step (a), the molar ratios of silicon source I, aluminum source I, water, organic matter I, and organic matter II are as follows: silicon source I: aluminum source I: water: organic matter I: organic matter II = 1: (0-0.02): (5-20): (0.1-1.0): (0.05-0.3), where silicon source I and aluminum source I are calculated as SiO2 and Al2O3, respectively. In step (c), the molar ratios of silicon source II, aluminum source II, water, template agent, and organic compound III are as follows: silicon source II: aluminum source II: water: template agent: organic compound III = 1: (0.0033-0.010): (8-20): (0.1-0.3): (0.01-0.10). The mass ratio of the mixture B to the total mass of the five substances (silicon source II, aluminum source II, water, template agent, and organic compound III) is (0.05-0.2): 1, wherein silicon source II and aluminum source II are calculated as SiO2 and Al2O3, respectively.

5. The preparation method according to claim 4, characterized in that, In step (a), organic compound I is one or more of tetrapropylammonium hydroxide, ethylamine, ethylenediamine, n-butylamine, butanediamine, hexamethyleneimine, and piperidine.

6. The preparation method according to claim 4, characterized in that, In step (a), silicon source I is one or more of tetramethyl silicate, tetraethyl silicate, tetrapropyl silicate, tetrabutyl silicate, and tetraphenyl silicate; and / or, in step (a), aluminum source I is one or more of aluminum sulfate, aluminum isopropoxide, sodium aluminate, and boehmite.

7. The preparation method according to claim 4, characterized in that, The treatment in step (b) is to stir at 60-130°C for 1-72 hours under sealed conditions; and / or, the crystallization conditions in step (d) are to crystallize at 110-170°C for 6-72 hours under sealed conditions.

8. The preparation method according to claim 4, characterized in that, In step (c), silicon source II is one or more of silica sol, silica fume, silica powder, tetramethyl silicate, tetraethyl silicate, tetrapropyl silicate, tetrabutyl silicate, and tetraphenyl silicate; and / or, in step (c), aluminum source II is one or more of aluminum nitrate, aluminum chloride, aluminum sulfate, aluminum isopropoxide, sodium aluminate, and boehmite; and / or, in step (c), template agent is one or more of tetrapropylammonium bromide, tetrapropylammonium hydroxide, ethylamine, ethylenediamine, n-propylamine, propylenediamine, n-butylamine, butylenediamine, n-hexylamine, hexamethylenediamine, ammonia, hexamethyleneimine, piperidine, and piperazine.

9. A catalyst for the alkylation of benzene to ethylbenzene, characterized in that, The catalyst comprises the molecular sieve of any one of claims 1-3 or the molecular sieve prepared by any one of claims 4-8, optionally comprising alumina.

10. The catalyst according to claim 9, characterized in that, The catalyst, based on its mass, contains more than 80% molecular sieve and less than 20% alumina.

11. The catalyst according to claim 10, characterized in that, The catalyst, based on its mass, contains 80%-90% molecular sieve and 10%-20% alumina.

12. The catalyst according to claim 10, characterized in that, The catalyst has a micropore volume of 0.13-0.17 cm³. 3 ·g -1 The mesopore volume is 0.50-0.80 cm³. 3 ·g -1 Its mechanical strength is 50-120 N / cm, and its bulk density is 0.50-0.60 g·cm³. -3 .

13. A method for preparing a catalyst for the alkylation of benzene to ethylbenzene, comprising: (e) The catalyst is obtained by mixing at least one molecular sieve of any of the molecular sieves described in claims 1-3 and any of the molecular sieves prepared by the method described in claims 4-8, alumina and a polymer mixture, followed by drying, calcination, ammonium exchange, steam treatment and acid washing.

14. The preparation method according to claim 13, characterized in that, In step (e), the alumina is alumina monohydrate; and / or, in step (e), the polymer mixture is a mixture of starch and at least one substance selected from hexadecyltrimethylammonium bromide, P123 or F127, wherein the starch accounts for 55%-70% of the mass of the polymer mixture.

15. The preparation method according to claim 13, characterized in that, In step (e), the mass ratio of molecular sieve E, alumina and polymer mixture is: molecular sieve E: alumina: polymer mixture = 1: (0.1-0.4): (0.03-0.2).

16. The preparation method according to claim 13, characterized in that, In step (e), the drying conditions are 100-200℃ for 5-12 hours; the calcination conditions are 500-600℃ for 4-10 hours; and the steam treatment conditions are 300-450℃ in a saturated steam atmosphere for 4-10 hours.

17. A method for producing ethylbenzene by benzene alkylation, characterized in that, The reactants benzene and ethylene are contacted with the catalyst described in any one of claims 9-12 or the catalyst prepared by any one of claims 13-16 to generate ethylbenzene.

18. The method according to claim 17, characterized in that, The ethylene feedstock has an ethylene mass concentration of 10%-100%; and / or, the reaction conditions are as follows: reaction temperature of 320-380℃, reaction pressure of 0.5-2.6 MPa, and ethylene mass hourly space velocity of 0.2-1.0 h⁻¹. -1 The molar ratio of benzene to ethylene is 4.0-6.0.

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