Catalyst for synthesis of tert-butyl toluene, and preparation method and application thereof

Abstract

The invention discloses a catalyst for synthesis of tert-butyltoluene as well as a preparation method and application of the catalyst. The catalyst comprises a single-layer-structure MWW molecular sieve, a binder, a rare earth metal oxide and an alkaline earth metal oxide. The catalyst has the characteristics of high active site utilization rate and adjustable pore structure, and shows high activity and high para-position product selectivity in the alkylation reaction of toluene and isobutene.

Description

Technical Field

[0001] This application relates to a catalyst for the synthesis of tert-butyltoluene and its preparation method, belonging to the field of inorganic material chemical synthesis. Background Technology

[0002] tert-Butyltoluene is an organic synthesis intermediate. Its derivatives, such as p-tert-butylbenzaldehyde, p-tert-butylbenzoic acid, methyl p-tert-butylbenzoate, and p-tert-butylbenzyl chloride, have a wide range of applications and can be used to manufacture resins, pharmaceuticals, pesticides, fragrances, etc.

[0003] The alkylation of toluene with isobutylene to produce p-tert-butyltoluene is an important production route. Concentrated sulfuric acid is commonly used as a catalyst in this process, which can easily cause equipment corrosion and environmental pollution. Patent CN 111408319B reports a novel reactor designed using concentrated sulfuric acid as a catalyst. This reactor allows for single-stream toluene feeding and multi-stream isobutylene feeding, resulting in uniform material mixing, controllable reaction temperature, high yield of the target product, and low catalyst usage. Patent CN 104926590 A reports the use of protic acid-p-methylbenzenesulfonic acid as a catalyst, combined with a reaction process design that introduces isobutylene in three stages, achieving a high toluene conversion rate. Notably, it reduces the amount of sulfuric acid used to one-twelfth of the original amount.

[0004] Molecular sieve catalysts exhibit outstanding activity in many reactions due to their tunable acidity and large specific surface area, and shape selectivity in many reactions due to their unique pore structure. For the reaction of toluene and isobutylene to produce p-tert-butyltoluene, patent CN 115772057 A uses phosphorus-modified MCM-22 molecular sieve as a catalyst; patent CN 118515522A uses a composite catalyst of resin and molecular sieve; and patent CN 118702538 A uses a beta-modified catalyst, eliminating the use of liquid acid and reducing equipment corrosion and environmental impact. Patent CN 115770610 B discloses a core-shell solid acid MCM-22 catalyst encapsulated by silicon and aluminum sources, which improves the selectivity for tert-butyltoluene. Summary of the Invention

[0005] The purpose of this invention is to develop a catalyst for the synthesis of tert-butyltoluene and a method for its preparation. The catalyst comprises a single-layer MWW molecular sieve, a binder, rare earth metal oxides, and alkaline earth metal oxides. The catalyst features both high active site utilization and tunable pore structure, exhibiting high activity and high para-product selectivity in the alkylation reaction of toluene and isobutylene.

[0006] According to a first aspect of this application, a catalyst for the synthesis of tert-butyltoluene is provided, said catalyst comprising a monolayer MWW molecular sieve, a binder, rare earth metal oxides, and alkaline earth metal oxides.

[0007] Optionally, the catalyst comprises 59.0 wt% to 89.8 wt% of a single-layer MWW molecular sieve, 10.0 wt% to 31.7 wt% of a binder, 0.1 wt% to 4.5 wt% of rare earth metal oxides and 0.1 wt% to 4.8 wt% of alkaline earth metal oxides.

[0008] Optionally, the adhesive is selected from alumina or silicon dioxide.

[0009] Optionally, the rare earth metal in the rare earth metal oxide is selected from at least one of lanthanum and cerium;

[0010] The alkaline earth metal in the alkaline earth metal oxide is selected from at least one of magnesium and calcium.

[0011] According to a second aspect of this application, a method for preparing the above-mentioned catalyst is provided, the method comprising:

[0012] (1) Mix the single-layer structure MWW molecular sieve and binder, then add guar gum powder and mix evenly. Knead and extrude the mixture with dilute nitric acid solution, then dry and calcine to obtain the molded product a;

[0013] (2) The molded product a was subjected to ion exchange, water washing, drying and calcination with dilute hydrochloric acid or ammonium chloride solution to obtain hydrogen-form molded product b.

[0014] (3) The hydrogen-formed compound b was impregnated with a rare earth metal salt solution. After impregnation, it was dried and calcined to obtain solid material c.

[0015] (4) The solid material c is impregnated with an alkaline earth metal salt solution. After impregnation, it is dried and calcined to obtain the catalyst.

[0016] Optionally, the single-layer structure MWW molecular sieve is obtained by a nanocellulose-assisted hydrothermal crystallization method.

[0017] Optionally, the preparation method includes:

[0018] (1) A single-layer MWW molecular sieve and a binder are mixed at a dry basis mass percentage of 65-90%:10-35%, and then 3-5% of guar gum powder is added and mixed evenly. The mixture is kneaded and extruded into strips using a dilute nitric acid solution with a mass concentration of 8-12% at a dry basis mass ratio of 0.4-0.8:1. The strips are then dried at 90-110℃ for 10-24 hours and calcined at 520-550℃ for 4-8 hours to obtain the molded product a.

[0019] (2) The molded product a is subjected to ion exchange, water washing, drying at 90-110℃ for 4-10h and calcination at 490-510℃ for 3-6h using dilute hydrochloric acid or ammonium chloride solution with a concentration of 0.1-0.3mol / L to obtain hydrogen-form molded product b. The ion exchange conditions are: temperature 60-80℃, time 60-120min, liquid-solid mass ratio 3-5 / 1, and continuous exchange 1-3 times before water washing; the water washing conditions are: 3 times, 1h / time, temperature 60-80℃, liquid-solid mass ratio 4-6 / 1.

[0020] (3) The hydrogen-formed material b is impregnated with a rare earth metal salt solution at a mass percentage of 0.1-5% of rare earth metal oxide and hydrogen-formed material b. The impregnation conditions are: temperature 40-70℃, time 0.5-2.0h. After impregnation, it is dried at 90-110℃ for 4-10h and calcined at 470-510℃ for 3-6h to obtain solid material c.

[0021] (4) The solid material c is impregnated with an alkaline earth metal salt solution at a mass percentage of 0.1-5% of alkaline earth metal oxide and solid material c. The impregnation conditions are: temperature 40-70℃, time 0.5-2.0h. After impregnation, the catalyst is dried at 90-110℃ for 4-10h and calcined at 470-510℃ for 3-6h to obtain the catalyst.

[0022] According to a third aspect of this application, a method for synthesizing tert-butyltoluene is provided, comprising mixing and reacting toluene with isobutylene in the presence of a catalyst to obtain the tert-butyltoluene; wherein the catalyst is selected from the above-mentioned catalysts.

[0023] Optionally, the reaction temperature is 160–220°C and the reaction pressure is 2.5–3.5 MPa.

[0024] Optionally, the upper limit of the reaction temperature is independently selected from 220°C, 200°C, and 180°C, and the lower limit is independently selected from 160°C, 200°C, and 180°C.

[0025] Optionally, the upper limit of the reaction pressure is independently selected from 3.5 MPa and 3 MPa, and the lower limit is independently selected from 2.5 MPa and 3 MPa.

[0026] Optionally, the molar ratio of toluene to isobutylene is 4.0–10.0, and the isobutylene space velocity is 0.2–0.5 h⁻¹. -1 .

[0027] Optionally, the upper limit of the toluene to isobutylene molar ratio is independently selected from 10, 8, and 6, and the lower limit is independently selected from 4, 6, and 8; the upper limit of the isobutylene space velocity is independently selected from 0.5 h⁻¹. -1 0.3h -1 The lower limit is independently selected from 0.2h.-1 0.3h -1 .

[0028] The beneficial effects that this application can produce include:

[0029] The catalyst features both high active site utilization and tunable pore structure, exhibiting high activity and high para-product selectivity in the alkylation reaction of toluene and isobutylene. The selectivity for p-tert-butyltoluene in tert-butyltoluene is greater than 85%. Detailed Implementation

[0030] The present application is further illustrated below with reference to specific embodiments. The following descriptions are merely a few embodiments of the present application and are not intended to limit the present application in any way. Although the present application discloses preferred embodiments as follows, they are not intended to limit the present application. Any modifications or variations made by those skilled in the art without departing from the scope of the technical solution of the present application using the disclosed technical content are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

[0031] Unless otherwise specified, the raw materials used in the embodiments of this application are all purchased commercially and used directly without any special treatment.

[0032] The specific composition of the raw materials used in this application embodiment is as follows:

[0033] Single-layer MWW molecular sieve: 90% dry basis;

[0034] Alumina: 71% (dry basis)

[0035] Example 1

[0036] (1) 100g of single-layer MWW molecular sieve and 68.2g of binder alumina were mixed at a dry basis mass percentage of 65%:35%, and then 4.2g of guar gum powder, accounting for 3% of the total dry basis mass, were added and mixed evenly. The mixture was then kneaded and extruded into strips with 346.2g of 8% dilute nitric acid solution at a mass ratio of 0.4:1 to the total dry basis mass. The strips were then dried at 90℃ for 24h and calcined at 520℃ for 8h to obtain the molded product a1.

[0037] (2) At a liquid-solid mass ratio of 5 / 1, 100g of molded material a1 was mixed with 435.0g of 0.8mol / L ammonium chloride solution for ammonium exchange at 80℃ for 60min; then, at a liquid-solid mass ratio of 6 / 1, it was mixed with 522.0g of water and washed three times at 60℃ for 1h each time; finally, it was dried at 110℃ for 10h and calcined at 510℃ for 3h to obtain hydrogen-form molded material b1.

[0038] (3) Test the water absorption of molded material b1. 100g of b1 absorbs 150g of water. According to the mass ratio of 0.1% lanthanum oxide, take 0.27g of lanthanum nitrate hexahydrate and dissolve it in 150g of water to form a mixed solution. Use this mixed solution to impregnate 100g of molded material b1 at 40℃ for 2h, then dry at 90℃ for 10h, and calcine at 510℃ for 3h to obtain solid material c1.

[0039] (4) The water absorption of solid material c1 was tested. 100g of c1 absorbed 155g of water. According to the mass ratio of magnesium oxide 0.1%, 3.7g of anhydrous magnesium nitrate was dissolved in 155g of water to form a mixed solution. 100g of solid material c1 was impregnated with this mixed solution at 40℃ for 2h, then dried at 90℃ for 10h, and calcined at 510℃ for 3h to obtain catalyst S1.

[0040] The conditions for using catalyst S1 in the alkylation reaction of toluene and isobutylene were: temperature 200℃, pressure 2.5 MPa, toluene to isobutylene molar ratio 4.0, and isobutylene weight hourly space velocity 1.0 h⁻¹. -1 Catalyst activity at different reaction times (toluene conversion, C2) MB (hereinafter the same) and the selectivity of tert-butyltoluene in tert-butyltoluene (S p-TBMB (The same applies below) As shown in Table 1.

[0041] Comparative Example 1

[0042] The catalyst preparation method is similar to that in Example 1. The parent molecular sieve used is a conventional multilayer MWW molecular sieve, and the product obtained is D1.

[0043] The conditions for using catalyst D1 in the alkylation reaction of toluene and isobutylene were: temperature 180℃, pressure 3.0 MPa, toluene to isobutylene molar ratio 6.0, and isobutylene weight hourly space velocity (WHSV) 0.4 h⁻¹. -1 Catalyst activity at different reaction times (toluene conversion, C2) MB (hereinafter the same) and the selectivity of tert-butyltoluene in tert-butyltoluene (S p-TBMB (The same applies below) As shown in Table 1.

[0044] Comparative Example 2

[0045] The catalyst preparation method is similar to that in Example 1. The catalyst is a single-layer MWW molecular sieve formed by extrusion without rare earth or alkaline earth modification. The catalyst is labeled as D2.

[0046] The conditions for using catalyst D2 in the alkylation reaction of toluene and isobutylene were: temperature 180℃, pressure 3.0 MPa, toluene to isobutylene molar ratio 6.0, and isobutylene weight hourly space velocity (WHSV) 0.4 h⁻¹. -1 Catalyst activity at different reaction times (toluene conversion, C2) MB(hereinafter the same) and the selectivity of tert-butyltoluene in tert-butyltoluene (S p-TBMB (The same applies below) As shown in Table 1.

[0047] Comparative Example 3

[0048] The catalyst preparation method is similar to that in Example 1. The catalyst is a single-layer MWW molecular sieve formed by extrusion, with only rare earth modification. The catalyst is labeled as D3.

[0049] The conditions for using catalyst D3 in the alkylation reaction of toluene and isobutylene were: temperature 180℃, pressure 3.0 MPa, toluene to isobutylene molar ratio 6.0, and isobutylene weight hourly space velocity (WHSV) 0.4 h⁻¹. -1 Catalyst activity at different reaction times (toluene conversion, C2) MB (hereinafter the same) and the selectivity of tert-butyltoluene in tert-butyltoluene (S p-TBMB (The same applies below) As shown in Table 1.

[0050] Comparative Example 4

[0051] The catalyst preparation method is similar to that in Example 1. The catalyst is a single-layer MWW molecular sieve formed by extrusion, and only alkaline earth modification is performed. The catalyst is labeled as D4.

[0052] The conditions for using catalyst D4 in the alkylation reaction of toluene and isobutylene were: temperature 180℃, pressure 3.0 MPa, toluene to isobutylene molar ratio 6.0, and isobutylene weight hourly space velocity (WHSV) 0.4 h⁻¹. -1 Catalyst activity at different reaction times (toluene conversion, C2) MB (hereinafter the same) and the selectivity of tert-butyltoluene in tert-butyltoluene (S p-TBMB (The same applies below) As shown in Table 1.

[0053] Example 2

[0054] (1) 100g of single-layer MWW molecular sieve and 6.7g of binder alumina were mixed at a dry basis mass percentage of 95%:5%, and then 4.7g of guar gum powder, accounting for 5% of the total dry basis mass, were added and mixed evenly. The mixture was then kneaded and extruded into strips with 118.4g of 8% dilute nitric acid solution at a mass ratio of 0.8:1 to the total dry basis mass. The strips were then dried at 110℃ for 10h and calcined at 550℃ for 4h to obtain the molded product a2.

[0055] (2) At a liquid-solid mass ratio of 5 / 1, 100g of molded material a2 was mixed with 435.0g of 0.8mol / L ammonium chloride solution for ammonium exchange at 80℃ for 60min; then, at a liquid-solid mass ratio of 6 / 1, it was mixed with 522.0g of water and washed three times at 60℃ for 1h each time; finally, it was dried at 110℃ for 10h and calcined at 510℃ for 3h to obtain hydrogen-form molded material b2.

[0056] (3) The water absorption of molded material b2 was tested. 100g of b2 absorbed 140g of water. According to the mass ratio of lanthanum oxide 5%, 1.35g of lanthanum nitrate hexahydrate was dissolved in 140g of water to form a mixed solution. 100g of molded material b2 was impregnated with this mixed solution at 70℃ for 0.5h, then dried at 110℃ for 4h, and calcined at 470℃ for 3h to obtain solid material c2.

[0057] (4) The water absorption of solid material c2 was tested. 100g of c2 absorbed 140g of water. According to the mass ratio of 5% magnesium oxide, 18.5g of anhydrous magnesium nitrate was dissolved in 140g of water to form a mixed solution. 100g of solid material c2 was impregnated with this mixed solution at 70℃ for 0.5h, then dried at 110℃ for 4h, and calcined at 470℃ for 3h to obtain the catalyst S2.

[0058] The conditions for using catalyst S2 in the alkylation reaction of toluene and isobutylene were: temperature 180℃, pressure 3.0 MPa, toluene to isobutylene molar ratio 6.0, and isobutylene weight hourly space velocity (WHSV) 0.4 h⁻¹. -1 Catalyst activity at different reaction times (toluene conversion, C2) MB (hereinafter the same) and the selectivity of tert-butyltoluene in tert-butyltoluene (S p-TBMB (The same applies below) As shown in Table 1.

[0059] Example 3

[0060] (1) 100g of single-layer MWW molecular sieve and 68.2g of binder alumina were mixed at a dry basis mass percentage of 65%:35%, and then 4.2g of guar gum powder, accounting for 3% of the total dry basis mass, were added and mixed evenly. The mixture was then kneaded and extruded into strips with 346.2g of 8% dilute nitric acid solution at a mass ratio of 0.4:1 to the total dry basis mass. The strips were then dried at 90℃ for 24h and calcined at 520℃ for 8h to obtain the molded product a3.

[0061] (2) At a liquid-solid mass ratio of 3 / 1, 100g of molded material a3 was mixed with 252.0g of 0.4mol / L ammonium chloride solution for ammonium exchange at 60℃ for 120min; then at a liquid-solid mass ratio of 4 / 1, it was mixed with 336.0g of water and washed with water three times at 60℃ for 1h each time; finally, it was dried at 110℃ for 10h and calcined at 510℃ for 3h to obtain hydrogen-form molded material b3.

[0062] (3) The water absorption of molded material b3 was tested. 100g of b3 absorbed 155g of water. According to the mass ratio of cerium oxide 0.5%, 1.26g of cerium nitrate hexahydrate was dissolved in 155g of water to form a mixed solution. 100g of molded material b3 was impregnated with this mixed solution at 40℃ for 1h, then dried at 100℃ for 8h, and calcined at 500℃ for 4h to obtain solid material c3.

[0063] (4) The water absorption of solid material C3 was tested. 100g of C3 absorbed 150g of water. According to the mass ratio of 1% magnesium oxide, 2.36g of anhydrous magnesium chloride was dissolved in 155g of water to form a mixed solution. 100g of solid material C3 was impregnated with this mixed solution at 40℃ for 1h, then dried at 100℃ for 8h, and calcined at 500℃ for 4h to obtain the catalyst S3.

[0064] The conditions for using catalyst S3 in the alkylation reaction of toluene and isobutylene were: temperature 180℃, pressure 3.0 MPa, toluene to isobutylene molar ratio 6.0, and isobutylene weight hourly space velocity (WHSV) 0.4 h⁻¹. -1 Catalyst activity at different reaction times (toluene conversion, C2) MB (hereinafter the same) and the selectivity of tert-butyltoluene in tert-butyltoluene (S p-TBMB (The same applies below) As shown in Table 1.

[0065] Example 4

[0066] (1) 100g of single-layer MWW molecular sieve and 6.7g of binder alumina were mixed at a dry basis mass percentage of 95%:5%, and then 4.7g of guar gum powder, accounting for 5% of the total dry basis mass, were added and mixed evenly. The mixture was then kneaded and extruded into strips with 118.4g of 8% dilute nitric acid solution at a mass ratio of 0.8:1 to the total dry basis mass. The strips were then dried at 110℃ for 10h and calcined at 550℃ for 4h to obtain the molded product a4.

[0067] (2) At a liquid-solid mass ratio of 3 / 1, 100g of molded material a4 was mixed with 252.0g of 0.4mol / L ammonium chloride solution for ammonium exchange at 60℃ for 120min; then, at a liquid-solid mass ratio of 4 / 1, it was mixed with 336.0g of water and washed three times at 60℃ for 1h each time; finally, it was dried at 110℃ for 10h and calcined at 510℃ for 3h to obtain hydrogen-form molded material b4.

[0068] (3) The water absorption of molded material b4 was tested. 100g of b4 absorbed 135g of water. According to the mass ratio of 0.5% cerium oxide, 1.26g of cerium nitrate hexahydrate was dissolved in 135g of water to form a mixed solution. 100g of molded material b4 was impregnated with this mixed solution at 40℃ for 2h, then dried at 100℃ for 10h, and calcined at 500℃ for 4h to obtain solid material c4.

[0069] (3) The water absorption of the molded part c4 was tested. 100g of c4 absorbed 140g of water. According to the mass ratio of 1% calcium oxide, 1.48g of anhydrous calcium nitrate was dissolved in 140g of water to form a mixed solution. 100g of molded part b4 was impregnated with this mixed solution at 0℃ for 2h, then dried at 100℃ for 10h, and calcined at 500℃ for 4h to obtain the catalyst S4.

[0070] The conditions for using catalyst S4 in the alkylation reaction of toluene and isobutylene were: temperature 180℃, pressure 3.0 MPa, toluene to isobutylene molar ratio 6.0, and isobutylene weight hourly space velocity (WHSV) 0.4 h⁻¹. -1 Catalyst activity at different reaction times (toluene conversion, C2) MB (hereinafter the same) and the selectivity of tert-butyltoluene in tert-butyltoluene (S p-TBMB (The same applies below) As shown in Table 1.

[0071] Example 5

[0072] (1) 100g of single-layer MWW molecular sieve and 6.7g of binder alumina were mixed at a dry basis mass percentage of 95%:5%, and then 4.7g of guar gum powder, accounting for 5% of the total dry basis mass, were added and mixed evenly. The mixture was then kneaded and extruded into strips with 118.4g of 8% dilute nitric acid solution at a mass ratio of 0.8:1 to the total dry basis mass. The strips were then dried at 110℃ for 10h and calcined at 550℃ for 4h to obtain the molded product a5.

[0073] (2) At a liquid-solid mass ratio of 5 / 1, 100g of molded material a5 was mixed with 415.0g of 0.8mol / L ammonium chloride solution for ammonium exchange at 80℃ for 60min; then, at a liquid-solid mass ratio of 5 / 1, it was mixed with 830.0g of water and washed three times at 80℃ for 1h each time; finally, it was dried at 90℃ for 4h and calcined at 510℃ for 3h to obtain hydrogen-form molded material b5.

[0074] (3) The water absorption of molded material b5 was tested. 100g of b5 absorbed 140g of water. According to the mass ratio of 2% cerium oxide, 5.04g of cerium nitrate hexahydrate was dissolved in 140g of water to form a mixed solution. 100g of molded material b5 was impregnated with this mixed solution at 40℃ for 1h, then dried at 100℃ for 8h, and calcined at 500℃ for 4h to obtain solid material c5.

[0075] (4) The water absorption of solid material c5 was tested. 100g of c5 absorbed 150g of water. According to the mass ratio of 1% calcium oxide, 1.48g of anhydrous calcium nitrate was dissolved in 150g of water to form a mixed solution. 100g of molded material b5 was impregnated with this mixed solution at 40℃ for 1h, then dried at 100℃ for 8h, and calcined at 500℃ for 4h to obtain the catalyst S5.

[0076] The conditions for using catalyst S5 in the alkylation reaction of toluene and isobutylene were: temperature 180℃, pressure 3.0 MPa, toluene to isobutylene molar ratio 6.0, and isobutylene weight hourly space velocity (WHSV) 0.4 h⁻¹. -1 Catalyst activity at different reaction times (toluene conversion, C2) MB (hereinafter the same) and the selectivity of tert-butyltoluene in tert-butyltoluene (S p-TBMB (The same applies below) As shown in Table 1.

[0077] Table 1

[0078]

[0079] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A catalyst for the synthesis of tert-butyltoluene, characterized in that, The catalyst comprises a single-layer MWW molecular sieve, a binder, rare earth metal oxides, and alkaline earth metal oxides.

2. The catalyst according to claim 1, characterized in that, The catalyst comprises 59.0 wt% to 89.8 wt% of a single-layer MWW molecular sieve, 10.0 wt% to 31.7 wt% of a binder, 0.1 wt% to 4.5 wt% of rare earth metal oxides and 0.1 wt% to 4.8 wt% of alkaline earth metal oxides.

3. The catalyst according to claim 1 or 2, characterized in that, The adhesive is selected from either alumina or silicon dioxide.

4. The catalyst according to claim 1 or 2, characterized in that, The rare earth metal in the rare earth metal oxide is selected from at least one of lanthanum and cerium; The alkaline earth metal in the alkaline earth metal oxide is selected from at least one of magnesium and calcium.

5. The method for preparing the catalyst according to any one of claims 1 to 4, characterized in that, The method for preparing the catalyst includes: (1) Mix the single-layer structure MWW molecular sieve and binder, then add guar gum powder and mix evenly. Knead and extrude the mixture with dilute nitric acid solution, then dry and calcine to obtain the molded product a; (2) The molded product a was subjected to ion exchange, water washing, drying and calcination with dilute hydrochloric acid or ammonium chloride solution to obtain hydrogen-form molded product b. (3) The hydrogen-form molded material b was impregnated with a rare earth metal salt solution. After impregnation, it was dried and calcined to obtain solid material c. (4) The solid material c is impregnated with an alkaline earth metal salt solution. After impregnation, it is dried and calcined to obtain the catalyst.

6. The preparation method according to claim 5, characterized in that, The single-layer structure MWW molecular sieve was obtained by nanocellulose-assisted hydrothermal crystallization.

7. The preparation method according to claim 4, characterized in that, The preparation method includes: (1) A single-layer MWW molecular sieve and a binder are mixed at a dry basis mass percentage of 65-90%:10-35%, and then 3-5% of guar gum powder is added and mixed evenly. The mixture is kneaded and extruded into strips using a dilute nitric acid solution with a mass concentration of 8-12% at a dry basis mass ratio of 0.4-0.8:

1. The strips are then dried at 90-110℃ for 10-24 hours and calcined at 520-550℃ for 4-8 hours to obtain the molded product a. (2) The molded product a is subjected to ion exchange, water washing, drying at 90-110℃ for 4-10h and calcination at 490-510℃ for 3-6h using dilute hydrochloric acid or ammonium chloride solution with a concentration of 0.1-0.3mol / L to obtain hydrogen-form molded product b. The ion exchange conditions are: temperature 60-80℃, time 60-120min, liquid-solid mass ratio 3-5 / 1, and continuous exchange 1-3 times before water washing; the water washing conditions are: 3 times, 1h / time, temperature 60-80℃, liquid-solid mass ratio 4-6 / 1. (3) The hydrogen-formed material b is impregnated with a rare earth metal salt solution at a mass percentage of 0.1-5% of rare earth metal oxide and hydrogen-formed material b. The impregnation conditions are: temperature 40-70℃, time 0.5-2.0h. After impregnation, it is dried at 90-110℃ for 4-10h and calcined at 470-510℃ for 3-6h to obtain solid material c. (4) The solid material c is impregnated with an alkaline earth metal salt solution at a mass percentage of 0.1-5% of alkaline earth metal oxide and solid material c. The impregnation conditions are: temperature 40-70℃, time 0.5-2.0h. After impregnation, the catalyst is dried at 90-110℃ for 4-10h and calcined at 470-510℃ for 3-6h to obtain the catalyst.

8. A method for synthesizing tert-butyltoluene, characterized in that, Toluene and isobutylene are mixed and reacted in the presence of a catalyst to obtain the tert-butyltoluene; The catalyst is selected from the catalysts described in any one of claims 1 to 4.

9. The synthesis method according to claim 8, characterized in that, The reaction temperature is 160–220℃, and the reaction pressure is 2.5–3.5 MPa.

10. The synthesis method according to claim 9, characterized in that, The molar ratio of toluene to isobutylene is 4.0–10.0, and the space velocity of isobutylene is 0.2–0.5 h⁻¹. -1 .

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