Preparation method and application of modified microporous composite zeolite catalyst

Abstract

The invention discloses a preparation method and application of a modified microporous composite zeolite catalyst, and belongs to the technical field of catalysts for efficient synthesis of p-diethylbenzene. The method comprises the following steps: adding ZSM-5 zeolite and a phase transfer reagent in a process of synthesizing Silicate-1 according to a theoretical ratio, and synthesizing a catalyst precursor through a hydrothermal reaction; the obtained precursor is subjected to acid treatment, titanium or silanization, continuous modification of two oxides, washing, drying and roasting, and finally the catalyst is obtained. The prepared catalyst has the advantages of being high in activity, good in target product selectivity, easy to reuse and regenerate and the like in a reaction for synthesizing p-diethylbenzene through ethylbenzene ethanol / ethylene alkylation, and has a wide application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of high-efficiency catalytic synthesis of p-diethylbenzene, and in particular relates to a preparation method and application of a modified microporous composite zeolite catalyst. Background Art

[0002] p-Diethylbenzene is an important organic chemical raw material and one of the important petrochemical products used as a desorbent in the process of catalytic reforming of naphtha to produce p-xylene. It is mainly used as a desorbent in industrial separation processes and as a raw material for preparing benzodisulfide. p-Diethylbenzene can be dehydrogenated at high temperature and fractionated to obtain p-divinylbenzene. p-Divinylbenzene is an important cross-linking agent and can be used as an ion exchange resin, polyester resin and polymerization monomer component, and can also be used as an improver for polyethylene and styrene-butadiene rubber. p-Diethylbenzene can be aminated to obtain terephthalamide, which can be further acidified to obtain terephthalic acid. The reaction of terephthalic acid and decanediamine can produce poly(terephthalic acid decanediamine).

[0003] The alkylation of ethylbenzene ethanol / ethylene to prepare diethylbenzene is a typical acid-catalyzed reaction. The reaction can be carried out using existing alkylation catalysts, such as AlCl3, FeCl3, BF3, HF, HCl or molecular sieve catalysts. At present, my country mainly relies on aromatics combined units to produce p-diethylbenzene by adsorption separation, in which the adsorption separation process comes from abroad and the core technology cannot be independently controlled. Moreover, the selectivity of traditional catalysts for para-isomers is not high, which can lead to a yield very close to the thermodynamic equilibrium composition of diethylbenzene (para: meta: ortho) = 30:54:16. However, the technical route for the direct synthesis of p-diethylbenzene by alkylation of ethylbenzene independently developed by my country has the shortcomings of short catalyst life and low selectivity for p-diethylbenzene. Therefore, it is imperative to develop a new generation of highly stable and highly selective catalysts for the alkylation of ethylbenzene to produce p-diethylbenzene.

[0004] In their patent application with application number CN90101436.2, entitled "Catalyst for ethylbenzene-ethanol alkylation to para-diethylbenzene", Pan Lurang, Li Shuquan and others used the reaction of ethylbenzene and ethanol, modified HZSM-5 molecular sieve with aluminum, magnesium and other components and then calcined it, the highest ethylbenzene conversion rate was only 10%, and the para-diethylbenzene selectivity was between 95 and 98%; the ethylbenzene conversion rate in U.S. Patent US5811613 was 8%, and the para-diethylbenzene selectivity was between 97 and 98%. The reaction yields in the above two patent applications were both low, which was not conducive to industrialization, and the catalyst activity was low and the stability was poor.

[0005] In the patent application with application number CN200310116628.X, entitled "Preparation and Application of Nano-HZSM-5 Zeolite Metal Ion Composite Modified Catalyst", Wang Xiangsheng, Yang Zhiqiang et al. used nano-HZSM-5 molecular sieve and Al2O3 as the matrix, and loaded 1 to 2 active components containing lanthanum, silicon, phosphorus or magnesium respectively to prepare a modified catalyst. The obtained diethylbenzene yield was between 10.35% and 16.50%, and the selectivity for diethylbenzene was maintained at 97.0. However, the patent application The preparation of the catalyst requires multiple loadings, the preparation conditions are difficult to control, and multiple calcinations are required, the preparation energy consumption is high, and the catalyst preparation cost is high; Wang Guiru and Li Shuwen used silicon-mixed rare earth modified HZSM-5 molecular sieve catalyst in their patent application with application number CN94110202.5, entitled "Preparation and Application of Silicon-Mixed Rare Earth Modified Catalysts", and the ethylbenzene conversion rate was 19.2%, but the selectivity for diethylbenzene was only 95%. The relatively low selectivity limits the industrial application of the catalyst. Summary of the invention

[0006] In view of the above-mentioned shortcomings, the present invention provides a preparation method and application of a modified microporous composite zeolite catalyst, which has high ethylbenzene conversion rate, high acetophenone selectivity and high overall selectivity for target products.

[0007] The first aspect of the present invention is to protect a method for preparing a modified microporous composite zeolite catalyst, comprising the following steps:

[0008] After adding ZSM-5 zeolite and a phase transfer agent to the raw material for synthesizing Silicate-1, a hydrothermal reaction is carried out to obtain a first intermediate, and the intermediate is subjected to a first calcination to obtain a carrier of the composite catalyst.

[0009] The carrier of the composite catalyst is mixed with an ammonium salt solution and then subjected to a second calcination to obtain a hydrogen-type composite catalyst.

[0010] The hydrogen-type composite catalyst is mixed with an acidic solution and then subjected to a third calcination to obtain an acid-treated composite catalyst, wherein the acidic solution is an inorganic acid or an organic acidic solution.

[0011] There are two ways to complete this step. Choose one of them.

[0012] The first method is to perform a fourth calcination on the acid-treated composite catalyst after titanium alkylation or silanization to obtain a titanium alkylation or silanation-modified catalyst, and then load the titanium alkylation or silanation-modified catalyst with a metal oxide and perform a fifth calcination to obtain a second intermediate.

[0013] The second method is to load the metal oxide on the acid-treated composite catalyst and then perform a fourth calcination to obtain a metal oxide-modified catalyst, and then perform a fifth calcination on the metal oxide-modified catalyst after titanium alkylation or silanization to obtain a third intermediate.

[0014] The second intermediate or the third intermediate is loaded with a non-metallic oxide and then subjected to a sixth calcination to obtain a modified microporous composite zeolite catalyst.

[0015] Furthermore, the raw material for synthesizing Silicate-1 is a mixture of SiO2: template: water = 0.05-5: 0.05-2: 5-100. The mass of the ZSM-5 zeolite: the mass of SiO2 = 0.05-10: 1. The mass ratio of the phase transfer agent to the ZSM-5 zeolite is 0.1-5: 1. The conditions of the hydrothermal reaction are crystallization at 80-200°C for 6-120h. The temperature of the first calcination is 400-650°C, and the time of the first calcination is 2-120h.

[0016] Further, the silicon source used is one or more of quartz sand, silica gel, silica sol, methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and isopropyl orthosilicate in any proportion. The template used is one or more of tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide and tetraisopropylammonium hydroxide in any proportion. The phase transfer reagent used is one or more of glutamic acid, arginine, tetrapropylammonium bromide and hexadecyltrimethylammonium bromide in any proportion.

[0017] Furthermore, the mass ratio of the carrier of the composite catalyst to the ammonium salt solution is 0.2 to 5.0:1, and the mass concentration of the ammonium salt solution is 1 to 20%. The carrier of the composite catalyst is immersed in the ammonium salt solution for 0.5 to 96 hours and then the second calcination is performed. The temperature of the second calcination is 200 to 650° C., and the time of the second calcination is 4 to 120 hours. The ammonium salt in the ammonium salt solution is one of ammonium nitrate, ammonium sulfate, ammonium carbonate, ammonium chloride, and ammonium acetate, or multiple of them in any proportion.

[0018] Furthermore, the mass ratio of the hydrogen-type composite catalyst to the acidic solution is 0.2 to 5:1, and the mass concentration of the acidic solution is 0.5 to 15%. The hydrogen-type composite catalyst is immersed in the acidic solution for 0.5 to 96 hours and then subjected to a third calcination. The temperature of the third calcination is 200 to 650° C., and the time of the third calcination is 4 to 120 hours. The acid in the acidic solution is one of formic acid, propionic acid, nitric acid, sulfuric acid, acetic acid, oxalic acid, citric acid, hydrochloric acid, and phosphoric acid, or multiple of any proportion.

[0019] Furthermore, in the titanium alkylation or silanization treatment in the first method or the second method, an alkane solution of a titanate or orthosilicate with a mass fraction of 0.5 to 40% is used, and the mass ratio of the alkane solution of the titanate or orthosilicate to the acid-treated composite catalyst or the metal oxide-modified catalyst is 0.5 to 50:1. In the first method, the mass of SiO2 or TiO2 obtained after the fourth calcination accounts for 0.25 to 25% of the mass of the acid-treated composite catalyst; in the second method, the mass of SiO2 or TiO2 obtained after the fifth calcination accounts for 0.25 to 25% of the mass of the metal oxide-modified catalyst; the temperature of the fourth or fifth calcination is 400 to 650°C, and the time of the fourth or fifth calcination is 4 to 120 hours.

[0020] Furthermore, in the first method or the second method, the metal oxide is 0.2 to 20.0% of the mass of the acid-treated composite catalyst or the titanium alkylated or silanized modified catalyst; the salt of the metal oxide is one or more of Ni(C2H3O2)2, Co(NO3)2, Ni(NO3)2, La(NO3)3, Fe(NO)3, Fe(C2H3O2)2, Ce(NO3)3, Sm(NO3)3, Y(NO3)3, NiCl2, CoCl2, LaCl3, FeCl3, FeCl2, CeCl3, SmCl3, and YCl3; the temperature of the fourth or fifth calcination is 400 to 650°C, and the time of the fourth or fifth calcination is 4 to 120 hours.

[0021] Furthermore, the non-metallic oxide is 0.5 to 30% of the mass of the second intermediate or the third intermediate; the salt of the non-metallic oxide is at least one of NaH2PO4, NH4H2PO4, (NH4)3PO4, Na3PO4, Na2HPO4, (NH4)2HPO4, Li2HPO4, LiH2PO4, Na2B4O7, NaBO2, NH4BO2, (NH4)3BO3, (NH4)2B4O7, and Na3BO3; the temperature of the sixth calcination is 400 to 650°C, and the time of the sixth calcination is 4 to 120 hours.

[0022] The second aspect of the present invention protects the use of the above-mentioned modified microporous composite zeolite catalyst in the synthesis of p-diethylbenzene.

[0023] Beneficial effects: The present invention sequentially and continuously modifies the microporous composite zeolite by acid treatment and silanization, and then loads a metal oxide and a non-metal oxide, thereby obtaining an environmentally friendly, highly active and easily separable catalyst for ethylbenzene ethanol / ethylene alkylation. The catalyst is suitable for ethylbenzene ethanol / ethylene alkylation reaction. In the reaction of ethylbenzene ethanol / ethylene alkylation to prepare high value-added products of p-diethylbenzene, it has the advantages of high activity, good selectivity of target products, easy reuse and regeneration of the catalyst, and can significantly reduce the energy consumption of product separation. In addition, the catalyst of the present invention has the advantages of simple preparation, green environmental protection, and easy separation and recovery.

[0024] The catalyst prepared by the present invention has the advantages of high activity (conversion rate higher than 20%), good selectivity of target product (total product selectivity higher than 97.5%), easy reuse and regeneration of the catalyst in the reaction of ethylbenzene ethanol / ethylene alkylation to synthesize p-diethylbenzene, and has broad application prospects. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Comparative Example 1: Synthesis of Silicate-1

[0027] (1) A certain amount of ethyl orthosilicate, tetrapropylammonium hydroxide and water are uniformly mixed in a molar ratio of 0.28-0.50SiO2:0.17-0.60TPAOH:25-100H2O, stirred for 3 hours, and then placed in a hydrothermal kettle at 160-180°C for 36-48 hours.

[0028] (2) The obtained sample was washed, dried, and calcined in air at 500-600° C. for 4-24 h to obtain the catalyst, which was denoted as Silicate-1.

[0029] Comparative Example 2: Synthesis of ZSM-5

[0030] (1) A certain amount of water, sodium hydroxide and tetrapropylammonium hydroxide are fully dissolved and mixed until uniform. A certain amount of silicic acid (30%) is gradually added to the above solution in batches under stirring. After being fully shaken at room temperature for 11 hours, it is aged at 100°C for 16 hours. The above substances are in a molar ratio of 50-500 H2O: Na2O: 0.5-2.0 TPAOH: 1.5-6.0 SiO2. The obtained sample is recorded as colloidal seed.

[0031] (2) A certain amount of water, sodium hydroxide and sodium aluminate are fully mixed and dissolved in a molar ratio of 25-120 H2O: 0.05-0.25 Na2O: 0.005-0.10 Al2O3: 0.5-5.0 SiO2, and a certain amount of silicic acid (30%) is gradually added in batches under sufficient stirring and oscillated at room temperature for 1-2 hours.

[0032] (3) Add a small amount of the colloidal seed crystals prepared in step (1) to (2) and oscillate for another 1 hour. Then place the material in a PTFE-lined stainless steel reactor and crystallize at 160-180° C. for 36-48 hours.

[0033] (4) The obtained sample is washed and dried, and then calcined in air at 500-600° C. for 4-24 h to obtain the catalyst, which is denoted as ZSM-5.

[0034] Example 1

[0035] The carrier of the multi-step continuously modified microporous composite zeolite catalyst of the present invention is prepared in the following steps:

[0036] Under normal temperature, normal pressure and stirring conditions, tetraethyl orthosilicate and tetrapropylammonium hydroxide solution are added to water, wherein the dosage ratio of tetraethyl orthosilicate to tetrapropylammonium hydroxide is 0.5-4:1. After stirring evenly, ZSM-5 powder is added according to the mass of ZSM-5: mass of SiO2 = 0.1-5:1. Continue stirring evenly, then add arginine, according to the mass of arginine: mass of ZSM-5 = 0.1-5:1, and continue stirring evenly. The obtained solution is placed in a hydrothermal reactor and crystallized at 150-200°C for 36-48h. After washing and drying the obtained sample, it is roasted at 500-650°C for 4-24h to obtain the carrier of the composite catalyst.

[0037] Example 2

[0038] The multi-step continuously modified microporous composite zeolite catalyst of the present invention is prepared in the following steps:

[0039] a. Under normal temperature, pressure and stirring conditions, add tetraethyl orthosilicate and tetrapropylammonium hydroxide solution into water, wherein the dosage ratio of tetraethyl orthosilicate to tetrapropylammonium hydroxide is 0.5-4:1. After stirring evenly, add ZSM-5 powder according to the mass of ZSM-5: mass of SiO2 = 0.1-5:1, and continue stirring evenly. Place the obtained solution in a hydrothermal reactor and crystallize at 150-200°C for 40-48h. After washing and drying the obtained sample, calcine at 500-650°C for 4-24h to obtain the carrier of the composite catalyst.

[0040] b. The composite catalyst obtained in step a is placed in an ammonium salt solution with a mass concentration of 1 to 20% according to the ratio of the mass of the composite catalyst carrier to the mass of the ammonium salt solution = 0.2 to 5.0:1, and immersed for 4 to 24 hours. The obtained sample is washed and dried, and then calcined at 500 to 650° C. for 4 to 10 hours to obtain the hydrogen-type composite catalyst.

[0041] c. The hydrogen-type composite catalyst obtained in step b is immersed in an oxalic acid or citric acid solution according to the ratio of hydrogen-type composite catalyst mass: acid solution mass = 0.2-5.0:1, and is placed in an acid solution with a mass concentration of 1.0-10%. After immersion for 4-24 hours, the obtained sample is washed and dried, and then calcined at 500-650°C for 4-24 hours to obtain the acid-treated composite catalyst.

[0042] d. The acid-treated composite catalyst is placed in a benzene or cyclohexane solution of 5-20% by mass of ethyl orthosilicate and allowed to stand for 4-24 hours, heated to reflux at 80-100°C until the benzene or cyclohexane is evaporated, and calcined in air at 400-650°C for 4-24 hours. The concentration of the alkane solution of titanate or orthosilicate used is 5-15%, and the mass ratio of the mass of the titanate or orthosilicate to the mass ratio of the catalyst obtained in step c is 0.5-50:1, and the mass ratio of the SiO2 or TiO2 obtained after calcination to the mass ratio of the catalyst obtained in step c is 0.25-25%.

[0043] e. The acid-treated silanized composite catalyst is added to the lanthanum nitrate solution, according to the mass of metal oxide: the acid-treated composite catalyst after silanization = 0.2-20.0%: 1, immersed for 4-24 hours, filtered, washed, dried at 80-120°C for 4-24 hours and calcined in air at 400-650°C for 4-48 hours.

[0044] f. Add the catalyst obtained in step e to the diammonium phosphate solution, according to the mass of P2O5: the mass of the catalyst obtained in step d = 0.5 to 30%: 1, impregnate for 4 to 24 hours, filter, wash, dry at 80 to 120 ° C for 4 to 24 hours and calcine in air at 400 to 650 ° C for 4 to 48 hours to obtain a multi-step continuous modified microporous composite zeolite catalyst.

[0045] Example 3

[0046] The multi-step continuously modified microporous composite zeolite catalyst of the present invention is prepared in the following steps:

[0047] A composite catalyst carrier was prepared according to step a of Example 2, a hydrogen-type composite catalyst was prepared according to step b, and then an acid-treated composite catalyst was prepared according to step c. The catalyst was prepared in sequence according to the following steps:

[0048] d. The acid-treated composite catalyst is added to the lanthanum nitrate solution, according to the mass of metal oxide: acid-treated composite catalyst = 0.2 ~ 20.0%: 1, impregnated for 4 to 24 hours, filtered, washed, dried at 80 ~ 120 ° C for 4 to 24 hours and calcined in air at 400 ~ 650 ° C for 4 to 48 hours.

[0049] e. The catalyst obtained in step d is placed in a benzene or cyclohexane solution of ethyl orthosilicate with a mass fraction of 5-20% and allowed to stand for 4-24 hours, heated to reflux at 80-100°C until the benzene or cyclohexane is evaporated, and calcined in air at 400-650°C for 4-24 hours. The concentration of the alkane solution of titanate or orthosilicate used is 5-15%, and the mass ratio of the alkane solution to the catalyst obtained in step d is 0.5-50:1, and the mass ratio of SiO2 or TiO2 obtained after calcination to the mass ratio of the catalyst obtained in step d is 0.25-25%.

[0050] f. Add the catalyst obtained in step e to the diammonium phosphate solution, according to the mass of P2O5: the mass of the catalyst obtained in step d = 0.5 to 30%: 1, impregnate for 4 to 24 hours, filter, wash, dry at 80 to 120 ° C for 4 to 24 hours and calcine in air at 400 to 650 ° C for 4 to 48 hours to obtain a multi-step continuous modified microporous composite zeolite catalyst.

[0051] Application Example 1: Catalytic Reaction Performance Evaluation

[0052] The reaction activities of the catalytic ethylbenzene ethanol / ethylene alkylation reactions of Examples 1 to 3 and Comparative Examples 1 to 2 were determined.

[0053] The specific operation process is as follows: the reaction temperature is 350-380°C, the reaction time is 2-24h, the reaction pressure is 0.5-10atm, the molar ratio of the raw material liquid n(ethylbenzene):n(ethanol) or n(ethylene)=1:1.0-4.0, and the catalyst is loaded to maintain a weight hourly space velocity WHSV=1.0-2.5. The specific reaction results are shown in Tables 1 and 2.

[0054] Table 1 Reaction results of Examples 1 to 3

[0055]

[0056] Table 2 Reaction results of comparative examples 1 to 2

[0057]

[0058] Application Example 2: Catalyst regeneration performance evaluation

[0059] Catalysts were synthesized according to Examples 1 and 2, and their reaction performance after catalytic reaction of ethylbenzene ethanol / ethylene alkylation was measured. After the catalyst was recovered, it was regenerated in an air atmosphere at 500-650°C, and the catalytic reaction performance of the regenerated catalyst of ethylbenzene ethanol / ethylene alkylation was measured. The reaction conditions were the same as those in Application Example 1, and the specific reaction results are shown in Table 3.

[0060] Table 3 Catalyst regeneration reaction results

[0061]

[0062] The experimental results show that the catalytic activity of Example 2 of the present invention for the alkylation of ethylbenzene ethanol / ethylene is the highest, and its activity is better than that of Silicate-1 and ZSM-5 zeolite catalysts. This indicates that the microporous composite zeolite catalyst that has been acid-treated, titanium or silanized, and continuously modified with two oxides has the best catalytic activity and selectivity for the target product. The catalyst of the present invention is suitable for the green synthesis of p-diethylbenzene by alkylation of ethylbenzene ethanol / ethylene. In the reaction of alkylation of ethylbenzene ethanol / ethylene to produce p-diethylbenzene with high added value, it has the advantages of high activity, good selectivity for the target product, and easy reuse and regeneration of the catalyst, and can significantly reduce the energy consumption required for separating the product m-diethylbenzene.

[0063] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a modified microporous composite zeolite catalyst, It is characterized in that The steps include: Adding ZSM-5 zeolite and a phase transfer agent to the raw material for synthesizing Silicate-1, and then performing a hydrothermal reaction to obtain a first intermediate, and performing a first calcination on the intermediate to obtain a carrier of the composite catalyst; The carrier of the composite catalyst is mixed with an ammonium salt solution and then subjected to a second calcination to obtain a hydrogen-type composite catalyst; The hydrogen-type composite catalyst is mixed with an acidic solution and then subjected to a third calcination to obtain an acid-treated composite catalyst, wherein the acidic solution is an inorganic acid or an organic acidic solution; There are two ways to complete this step. Choose one of them. The first method is: subjecting the acid-treated composite catalyst to titanium alkylation or silanization treatment and then subjecting it to a fourth calcination to obtain a titanium alkylation or silanation-modified catalyst, and loading the titanium alkylation or silanation-modified catalyst with a metal oxide and subjecting it to a fifth calcination to obtain a second intermediate; The second method is: loading the metal oxide on the acid-treated composite catalyst and then performing a fourth calcination to obtain a metal oxide-modified catalyst, and performing a titanium alkylation or silanization treatment on the metal oxide-modified catalyst and then performing a fifth calcination to obtain a third intermediate; The second intermediate or the third intermediate is loaded with a non-metallic oxide and then subjected to a sixth calcination to obtain a modified microporous composite zeolite catalyst.

2. The method for preparing the modified microporous composite zeolite catalyst according to claim 1, It is characterized in that The raw materials for synthesizing Silicate-1 are SiO 2 :template agent:water=0.05~5:0.05~2:5~100 mixture; the mass of the ZSM-5 zeolite: SiO 2 mass = 0.05-10:1; the mass ratio of the phase transfer agent to the ZSM-5 zeolite is 0.1-5:1; the conditions of the hydrothermal reaction are 80-200°C crystallization for 6-120h; the temperature of the first calcination is 400-650°C, and the time of the first calcination is 2-120h.

3. The method for preparing the modified microporous composite zeolite catalyst according to claim 1, It is characterized in that The silicon source used is: one of quartz sand, silica gel, silica sol, methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and isopropyl orthosilicate, or multiple of them in any proportion; the template used is one of tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide and tetraisopropylammonium hydroxide, or multiple of them in any proportion; the phase transfer reagent used is: one of glutamic acid, arginine, tetrapropylammonium bromide and hexadecyltrimethylammonium bromide, or multiple of them in any proportion.

4. The method for preparing the modified microporous composite zeolite catalyst according to claim 1, It is characterized in that The mass ratio of the carrier of the composite catalyst to the ammonium salt solution is 0.2-5.0:1, and the mass concentration of the ammonium salt solution is 1-20%; the carrier of the composite catalyst is immersed in the ammonium salt solution for 0.5-96 hours and then the second calcination is performed; the temperature of the second calcination is 200-650° C., and the time of the second calcination is 4-120 hours; the ammonium salt in the ammonium salt solution is one of ammonium nitrate, ammonium sulfate, ammonium carbonate, ammonium chloride, and ammonium acetate, or multiple of them in any proportion.

5. The method for preparing the modified microporous composite zeolite catalyst according to claim 1, It is characterized in that The mass ratio of the hydrogen-type composite catalyst to the acidic solution is 0.2-5:1, and the mass concentration of the acidic solution is 0.5-15%; the hydrogen-type composite catalyst is immersed in the acidic solution for 0.5-96 hours and then subjected to a third calcination; the temperature of the third calcination is 200-650°C, and the time of the third calcination is 4-120 hours; the acid in the acidic solution is one of formic acid, propionic acid, nitric acid, sulfuric acid, acetic acid, oxalic acid, citric acid, hydrochloric acid, and phosphoric acid, or multiple acids in any proportion.

6. The method for preparing the modified microporous composite zeolite catalyst according to claim 1, It is characterized in that In the titanium alkylation or silanization treatment in the first or second manner, an alkane solution of a titanate or orthosilicate with a mass fraction of 0.5 to 40% is used, and the mass ratio of the alkane solution of the titanate or orthosilicate to the acid-treated composite catalyst or the metal oxide-modified catalyst is 0.5 to 50:

1. In the first manner, the SiO 2 or TiO 2 The mass of the SiO obtained after the fifth calcination in the second method accounts for 0.25 to 25% of the mass of the acid-treated composite catalyst; 2 or TiO 2 The mass of the catalyst modified by the metal oxide accounts for 0.25 to 25% of the mass of the catalyst modified by the metal oxide; the temperature of the fourth or fifth calcination is 400 to 650° C., and the time of the fourth or fifth calcination is 4 to 120 hours.

7. The method for preparing the modified microporous composite zeolite catalyst according to claim 1, It is characterized in that In the first method or the second method, the metal oxide is 0.2 to 20.0% of the mass of the acid-treated composite catalyst or the titanium alkylated or silanated modified catalyst; the salt of the metal oxide is Ni(C 2 H 3 O 2 ) 2 、Co(NO 3 ) 2 ,Ni(NO 3 ) 2 、La(NO 3 ) 3 、Fe(NO) 3 、Fe(C 2 H 3 O 2 ) 2 、Ce(NO 3 ) 3 、Sm(NO 3 ) 3 、Y(NO 3 ) 3 、NiCl 2 、CoCl 2 、LaCl 3 、FeCl 3 、FeCl 2 、CeCl 3 、SmCl 3 , YCl 3 One or more of the foregoing in any proportion; the temperature of the fourth or fifth calcination is 400-650° C., and the time of the fourth or fifth calcination is 4-120 h.

8. The method for preparing the modified microporous composite zeolite catalyst according to claim 1, It is characterized in that The non-metallic oxide is 0.5-30% of the mass of the second intermediate or the third intermediate; the salt of the non-metallic oxide is NaH 2 PO 4 NH 4 H 2 PO 4 NH 4 ) 3 PO 4 、Na 3 PO 4 、Na 2 HPO 4 NH 4 ) 2 HPO 4 , Li 2 HPO 4 , LiH 2 PO 4 、Na 2 B 4 O 7 、NaBO 2 NH 4 BO 2 NH 4 ) 3 BO 3 NH 4 ) 2 B 4 O 7 、Na 3 BO 3 At least one of the following: the temperature of the sixth calcination is 400 to 650°C, and the time of the sixth calcination is 4 to 120 hours.

9. Use of a modified microporous composite zeolite catalyst prepared by the preparation method according to any one of claims 1 to 8 in the synthesis of p-diethylbenzene.

Images