A catalyst for the synthesis of tertiary dodecyl mercaptan from triisobutene and a process for its preparation and use

Abstract

The application provides a catalyst for synthesizing tertiary dodecyl mercaptan from triisobutene, a preparation method and use thereof. The method comprises the following steps: preparing a silicon source mixed solution A, preparing a gallium source mixed solution B, and preparing a structure directing agent mixed solution C; adding A into C, stirring, and then adding B to obtain a sol-like substance; adding a cerium source and / or a lanthanum source and an alkyl polyamine solution, stirring to obtain a mixed solution D, and continuously stirring to obtain a powder after drying; and calcining the powder to obtain a unit point rare earth regulated Si-Ga nanomaterial. The catalyst has excellent activity and super-long stability (more than 800 h) in a reaction for synthesizing tertiary dodecyl mercaptan from triisobutene as a raw material, and can be used for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of catalysts, specifically relating to a catalyst for the synthesis of tert-dodecyl mercaptan from triisobutylene, its preparation method, and its uses. Background Technology

[0002] Tertiary dodecyl mercaptan (TDM) is widely used in the synthesis of rubber, synthetic resins, polyolefins, ABS plastics, and pharmaceuticals, and is an extremely important chemical intermediate. Currently, the commercial synthesis of TDM involves the reaction of dodecylene with hydrogen sulfide. Dodecylene is composed of tetrapropylene and its isomer triisobutylene. Tetrapropylene and triisobutylene exhibit different molecular diffusion modes and reaction mechanisms during their reaction with hydrogen sulfide to produce TDM. Tetrapropylene, being a straight-chain olefin, more readily breaks its carbon-carbon double bonds and reacts with the thiol groups in hydrogen sulfide, resulting in fewer side reactions and thus high conversion and selectivity. It has been extensively studied, as evidenced by US4565893 and US4102931. However, due to the two branches in its molecular structure, the commercial catalysts currently available for the synthesis of TDM from triisobutylene generally suffer from low conversion, poor selectivity, and poor stability, severely hindering the industrialization of TDM production using triisobutylene as a raw material. Currently, the production of isobutylene in the chemical industry is gradually increasing. However, due to the promotion of ethanol gasoline, isobutylene will no longer be permitted to be blended into gasoline. Therefore, using isobutylene as a raw material to synthesize tert-dodecyl mercaptan, a basic chemical product, is of great significance.

[0003] However, in the process of synthesizing tert-dodecyl mercaptan from triisobutylene using hydrogen sulfide, the commercial catalysts currently used have low conversion rates, and there are also problems such as poor selectivity of tert-dodecyl mercaptan and easy deactivation of the catalyst. Summary of the Invention

[0004] One objective of this invention is to provide a method for preparing a catalyst for the synthesis of tert-dodecyl mercaptan from triisobutylene. This method allows the reaction to occur at a mild reaction temperature and low pressure, achieving a tert-dodecyl mercaptan yield greater than 85% and a stability greater than 800 h, making it suitable for industrial production.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] A method for preparing a catalyst for the synthesis of tert-dodecyl mercaptan from triisobutylene, the method comprising the following steps:

[0007] S1: Prepare silicon source mixture A, prepare gallium source mixture B, prepare structure-directing agent mixture C;

[0008] S2: Add A to C, stir, then add B to obtain a sol-like substance;

[0009] S3: Add cerium source and / or lanthanum source, add alkyl polyamine solution, stir to obtain mixture D, continue stirring, and dry to obtain powder;

[0010] S4: Calcined powder to obtain Si-Ga nanomaterials with rare earth element regulation at a single point.

[0011] In one embodiment of the present invention, the silicon source in S1 is an oxygen-containing silicon compound and / or a non-oxygen-containing silicon compound, preferably one or more of silicon tetrachloride, silica gel, water glass, sodium silicate, silica sol, silica, silicic acid, methyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), and alkoxysilanes, more preferably one or more of methyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), and alkoxysilanes. The above-mentioned silicon source is a preferred option, and those skilled in the art can select one as needed.

[0012] In one embodiment of the present invention, the gallium source in S1 is one or more selected from gallium salts, gallium esters, gallium oxide, and organogallium, preferably one or more selected from trimethylgallium, sodium gallate, gallium oxide, and gallium nitrate, and more preferably gallium nitrate. The above-mentioned gallium source is a preferred option, and those skilled in the art can select one as needed.

[0013] In one embodiment of the present invention, the structure directing agent in S1 is a micro-mesoporous structure directing agent, preferably one or more of P123, F127, and C18-6-5, more preferably C18-6-5. The micro-mesoporous structure directing agent C18-6-5 is [C 18 H 37 -N + (CH3)2-C6H 12 -N + (CH3)2-C5H 11 ]Br - 2; Preferably, the amounts of silicon source and gallium source are such that the Si / Ga mass ratio in the target Si-Ga nanomaterial is (2-37):1, more preferably (5-20):1, and even more preferably (8-15):1; preferably, the mass ratio of structure directing agent to gallium source is (15-65):1; more preferably (35-45):1. The above selection of directing agent and its amount is a preferred scheme, and those skilled in the art can select it as needed.

[0014] In one embodiment of the present invention, the cerium source and / or lanthanum source in S3 is a water-soluble cerium compound and / or a water-soluble lanthanum compound, preferably one or more of cerium acetate, cerium nitrate, cerium citrate, lanthanum acetate, lanthanum nitrate, and lanthanum citrate, more preferably cerium nitrate hexahydrate and / or lanthanum nitrate hexahydrate; preferably, the amount of cerium source and / or lanthanum source added is such that the mass ratio of Ce and / or La in the target Si-Ga nanomaterial is 0.02-4.5%, preferably 0.05-2%, and most preferably 0.1-1%. The above-mentioned cerium source and / or lanthanum source is a preferred option, and those skilled in the art can select it as needed.

[0015] In one embodiment of the present invention, the alkyl polyamine in S3 is a water-soluble alkyl polyamine, preferably one or more of water-soluble alkyl polyamines with an N element quantity of 2-8, more preferably hexamethoxymethylmelamine and / or hexamethylenetetramine; preferably, the volume ratio of the added alkyl polyamine aqueous solution to the original solution is 1:(2-30), more preferably 1:(7-17); preferably, the concentration of the added alkyl polyamine aqueous solution is 0.1-2M. The above selection of alkyl polyamine and its dosage is a preferred option, and those skilled in the art can select according to their needs.

[0016] In one embodiment of the present invention, the Si-Ga nanomaterial described in S4 has a tetrahedral pyramidal structure.

[0017] Another object of the present invention is to provide a catalyst.

[0018] A catalyst, prepared by the above-described preparation method, wherein the catalyst is a Si-Ga catalyst with a tetragonal pyramidal structure and single-point rare earth controlled by rare earth elements; preferably, the mass ratio of Si / Ga in the catalyst is (2-37):1, more preferably (5-20):1, more preferably (8-15):1; preferably, the mass ratio of Ce and / or La in the catalyst is 0.02-4.5%, more preferably 0.05-2%, and most preferably 0.1-1%.

[0019] The novel Si-Ga catalyst material with a tetrahedral pyramidal structure and single-site rare earth (La / Ce) modulation in this invention inserts single-site Ce / La into unsaturated Ga sites, further modulating the local microenvironment of the Ga sites. By increasing and stabilizing the number of active sites (Brønsted acid) and inhibiting carbon and sulfur deposition on the catalyst during the reaction, the single-pass conversion rate and stability of the reaction are effectively improved.

[0020] Another object of the present invention is to provide a use for a catalyst.

[0021] The use of a catalyst, wherein the catalyst is a catalyst prepared by the above-described preparation method, or is a catalyst described above, wherein the catalyst is used to synthesize alkyl thiols, preferably for the synthesis of tert-dodecyl thiols from triisobutylene.

[0022] Compared with the prior art, the positive effects of the present invention are as follows:

[0023] (1) The catalyst of the present invention greatly improves the problem of poor activity in the process of synthesizing tert-dodecyl mercaptan by reacting triisobutylene with hydrogen sulfide. Compared with the commercial Amberlyst-15 resin catalyst (the optimal conversion rate of triisobutylene is no higher than 45%, and the selectivity of tert-dodecyl mercaptan is no higher than 85%), the catalyst of the present invention has an optimal single-pass conversion rate of triisobutylene greater than 85% and a selectivity of tert-dodecyl mercaptan greater than 98%.

[0024] (2) The catalyst of the present invention greatly improves the problem of poor stability in the process of reacting triisobutylene with hydrogen sulfide to synthesize tert-dodecyl mercaptan. Compared with the commercial Amberlyst-15 resin catalyst (after 120h, the triisobutylene conversion rate gradually decreases, and after 180h it drops to below 20%), the catalyst of the present invention still maintains a triisobutylene conversion rate of more than 80% after 800h of reaction.

[0025] (3) The catalyst synthesis process described in this invention is simple and the catalyst yield is high. At the same time, the catalyst has a special morphology, which is a tetragonal pyramidal structure composed of nano-Si-Ga microstructures, which significantly exposes the catalytic sites of the catalyst.

[0026] (4) The catalyst synthesized by the method of the present invention has good anti-carbon and anti-sulfur properties due to the regulation of rare earth Ce (La) element at the unit point. At the same time, compared with the traditional Si-Al catalyst, the Ga ions in the Si-Ga catalyst synthesized by this method are not easily lost, and the active sites required for catalyzing the reaction are stabilized, thus having high catalytic stability.

[0027] (5) The method of the present invention generates less waste liquid during the synthesis of catalyst, which can be produced on a large scale. At the same time, the catalyst regeneration is simple and suitable for industrial application. Attached Figure Description

[0028] Figure 1 The graph shows the triisobutylene conversion results in Examples 1-3;

[0029] Figure 2 The graph shows the selectivity results of the product tert-dodecyl mercaptan in Examples 1-3;

[0030] Figure 3 These are the stability test results for Examples 4 and 5, and Comparative Example 1;

[0031] Figure 4 The graph shows the conversion results of triisobutylene in Comparative Example 2;

[0032] Figure 5 The graph shows the selectivity results of the product tert-dodecylthiol in Comparative Example 2;

[0033] Figure 6 The figure shows the stability test results in Comparative Example 2;

[0034] Figure 7 This is a SEM image of the 0.5Ce / Si-Ga-10 catalyst in Example 4;

[0035] Figure 8 for Figure 7 The magnified result of the SEM image. Detailed Implementation

[0036] Preferred embodiments of the present invention will now be described in more detail through examples. While the examples illustrate preferred embodiments of the present invention, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0037] Raw material source:

[0038] Isobutylene, Wanhua Chemical Co., Ltd., purity greater than 98%; hydrogen sulfide, Dalian Date Gas Co., Ltd., purity greater than 99%; high-purity nitrogen, argon, and helium, Kunming Guangruida Gas Co., Ltd., all with purity greater than 99.99%. C18-6-5 (i.e., [C 18 H 37 -N + (CH3)2-C6H 12 -N + (CH3)2-C5H 11 ]Br - 2), P123 (i.e., polyoxyethylene-polyoxypropylene-polyoxyethylene, molecular weight 1200), Wanhua Chemical Co., Ltd.

[0039] Source of experimental reagents:

[0040] All experimental reagents used in this invention were purchased from Shanghai McLean Co., Ltd.

[0041] Analysis method:

[0042] instrument Manufacturer Analytical methods Gas chromatography Zhejiang Fuli Unity method

[0043] Gas chromatography analysis method, column temperature 50℃, hold for 5 min, then increase to 220℃ at 10℃ / min; FID detector detection, injection volume 0.5 μL.

[0044] The present invention will be further described in detail below with reference to specific embodiments. The catalysts prepared in the embodiments of the present invention are named xR / Si-Ga-y (x is the percentage of rare earth element added, and y represents the ratio of Si and Ga. Due to the preparation process, the above names are nominal ratios).

[0045] Examples 1-3

[0046] (1) Add 14.5 mL of tetraethyl orthosilicate to 50 mL of deionized water and sonicate for 10 min. Record this as A.

[0047] (2) Dissolve gallium nitrate (0.25g, 0.5g, and 1.0g in the three examples) in 10mL of deionized water and sonicate for 10min. This is recorded as B.

[0048] (3) Add 8g of C18-6-5 to 72mL of deionized water and stir vigorously at room temperature for 2.5h. Record this as C.

[0049] (4) Add A dropwise to C and stir at room temperature for 1 hour. Then quickly pour B into the above mixed solution and stir the resulting sol at 60°C for 3 hours.

[0050] (5) After stirring for 2 hours in step (4), add cerium nitrate hexahydrate aqueous solution dropwise (0.022 g, 0.023 g, and 0.025 g of cerium nitrate in the three examples, respectively) so that the amount of Ce added is 0.5% of the catalyst mass, and add 15 mL of hexamethylenetetramine solution (0.34 M), stir thoroughly, and record it as D.

[0051] (6) The above D was stirred vigorously at 5°C for 12 hours, then freeze-dried and calcined at 580°C for 5 hours in a muffle furnace (heating rate of 2°C / min). The resulting powder materials were named 0.5Ce / Si-Ga-5, 0.5Ce / Si-Ga-10, and 0.5Ce / Si-Ga-20.

[0052] The 0.5Ce / Si-Ga-10 catalyst exhibits a regular tetrahedral pyramidal structure, which is composed of Si-Ga nanoparticles, allowing for better exposure of active sites.

[0053] The catalyst obtained in this embodiment was applied to the synthesis reaction of tert-dodecyl mercaptan. The specific reaction conditions were as follows: 30 mL of the above catalyst was loaded into a 316 stainless steel reactor with an inner diameter of 16 mm and a length of 354 mm, and the pressure was adjusted to 1.0 MPaG; hydrogen sulfide and triisobutylene were simultaneously introduced into the reactor, with a hydrogen sulfide to olefin molar ratio of 3 and a space velocity of 0.6 h⁻¹. -1 Conversion rate and selectivity results are as follows: Figure 1 , 2 As shown.

[0054] Examples 4 and 5

[0055] (1) Add 14.5 mL of tetraethyl orthosilicate to 50 mL of deionized water and sonicate for 10 min. Record this as A.

[0056] (2) Dissolve 0.5g of gallium nitrate in 10mL of deionized water and sonicate for 10min. Record this as B.

[0057] (3) Add 8g of C18-6-5 to 72mL of deionized water and stir vigorously at room temperature for 2h. Record this as C.

[0058] (4) Add A dropwise to C and stir at room temperature for 1 hour. Then quickly pour B into the above mixed solution and stir the resulting sol at 60°C for 3 hours.

[0059] (5) After stirring for 2 hours in step (4), add cerium nitrate hexahydrate aqueous solution dropwise (0.023 g and 0.046 g of cerium nitrate in the two examples respectively). The Ce content of the product in the two examples is 0.5 wt% and 1 wt% respectively. Add 15 mL of hexamethylenetetramine solution (0.34 M) and stir thoroughly. This is recorded as D.

[0060] (6) The above D was vigorously stirred at 5°C for 12 hours, then freeze-dried and calcined at 580°C for 5 hours in a muffle furnace (heating rate of 2°C / min). The resulting powder materials were denoted as 0.5Ce / Si-Ga-10 and 1Ce / Si-Ga-10.

[0061] The catalyst obtained in this embodiment was applied to the synthesis reaction of tert-dodecyl mercaptan. The specific reaction conditions were as follows: 30 mL of the above catalyst was loaded into a 316 stainless steel reactor with an inner diameter of 16 mm and a length of 354 mm, and the pressure was 1.0 MPaG; hydrogen sulfide and triisobutylene were simultaneously introduced into the reactor, with a molar ratio of hydrogen sulfide to olefin of 3 and a space velocity of 0.6 h⁻¹. -1 The reaction temperature was 90℃, and the stability test results were as follows: Figure 3 The results showed that the addition of rare earth elements effectively improved the catalyst's resistance to carbon and sulfur deposition. The activity of the 0.5Ce / Si-Ga-10 catalyst with 0.5% Ce addition did not change significantly, and the dodecene conversion rate remained at 85% after 812 hours of stable operation, with almost no loss. The 1Ce / Si-Ga-10 catalyst with 1% Ce addition also showed significantly improved stability compared to the Si-Ga-10 without Ce addition, with only a slight decrease in activity. Figure 7 This is a SEM image of the 0.5Ce / Si-Ga-10 catalyst in Example 4; Figure 8 for Figure 7 The magnified result of the SEM image.

[0062] Example 6

[0063] (1) Add 14.5 mL of water glass to 50 mL of deionized water and sonicate for 10 min. Record this as A.

[0064] (2) Add 0.5g of trimethylgallium to 10mL of deionized water and sonicate for 10min. Record this as B.

[0065] (3) Add 8g of P123 to 72mL of deionized water and stir vigorously at room temperature for 3h. This is recorded as C.

[0066] (4) Add A dropwise to C and stir at room temperature for 1 hour. Then quickly pour B into the above mixed solution and stir the resulting sol at 60°C for 3 hours.

[0067] (5) After stirring for 2 hours in step (4), add dropwise lanthanum nitrate hexahydrate aqueous solution (lanthanum nitrate 0.0228 g, the amount added is such that the product contains 0.5 wt% La) and 12 mL of hexamethoxymethylmelamine mixture (0.54 M), stir thoroughly, and record as D.

[0068] (6) The above D was vigorously stirred at 5°C for 12 hours, then freeze-dried and calcined at 580°C for 5 hours in a muffle furnace (heating rate of 2°C / min). The resulting powder material was denoted as 0.5La / Si-Ga-10.

[0069] The catalyst obtained in this embodiment was applied to the synthesis reaction of tert-dodecyl mercaptan. The specific reaction conditions were as follows: 30 mL of the above catalyst was loaded into a 316 stainless steel reactor with an inner diameter of 16 mm and a length of 354 mm, and the pressure was 1.0 MPaG; hydrogen sulfide and triisobutylene were simultaneously introduced into the reactor, with a molar ratio of hydrogen sulfide to olefin of 3 and a space velocity of 0.6 h⁻¹. -1 The reaction temperature was 90℃. The results showed that the addition of rare earth elements per unit point effectively improved the catalyst's resistance to carbon and sulfur deposition, without significant change in catalyst activity. After 812 hours of stable operation, the conversion rate of dodecene was 83%, with almost no loss.

[0070] Comparative Example 1

[0071] Compared with Examples 4 and 5, the difference is that Ce is not added.

[0072] (1) Dissolve 14.5 mL of tetraethyl orthosilicate in 50 mL of deionized water and sonicate for 10 min. Record this as A.

[0073] (2) Dissolve 0.5g of gallium nitrate in 10mL of deionized water and sonicate for 10min. Record this as B.

[0074] (3) Add 8g of C18-6-5 to 72mL of deionized water and stir vigorously at room temperature for 2h. Record this as C.

[0075] (4) Add A dropwise to C and stir at room temperature for 1 hour. Then quickly pour B into the above mixed solution and stir the resulting sol at 60°C for 3 hours.

[0076] (5) After stirring for 2 hours in step (4), add 15 mL of hexamethylenetetramine solution (0.34 M) dropwise and stir thoroughly. Record this as D.

[0077] (6) The above D was vigorously stirred at 5°C for 12 hours, then freeze-dried and calcined at 580°C for 5 hours in a muffle furnace (heating rate of 2°C / min). The resulting powder material was denoted as Si-Ga-10.

[0078] The catalyst obtained in this embodiment was applied to the synthesis reaction of tert-dodecyl mercaptan. The specific reaction conditions were as follows: 30 mL of the above catalyst was loaded into a 316 stainless steel reactor with an inner diameter of 16 mm and a length of 354 mm, and the pressure was 1.0 MPaG; hydrogen sulfide and triisobutylene were simultaneously introduced into the reactor, with a molar ratio of hydrogen sulfide to olefin of 3 and a space velocity of 0.6 h⁻¹. -1 The reaction temperature was 90℃, and the stability test results were as follows: Figure 3 The results showed that the activity of the Si-Ga-10 catalyst without the addition of rare earth element Ce gradually decreased during operation, and after 812 h of operation, the activity gradually decreased from the initial 74% to 33%.

[0079] Comparative Example 2

[0080] The catalyst used in this comparative example was the commercial Amberlyst-15 resin catalyst. The specific reaction conditions were as follows: 30 mL of Amberlyst-15 resin catalyst was charged into a 316 stainless steel reactor with an inner diameter of 16 mm and a length of 354 mm, at a pressure of 1.0 MPaG; hydrogen sulfide and triisobutylene were simultaneously introduced into the reactor, with a hydrogen sulfide to olefin molar ratio of 3 and a space velocity of 0.6 h⁻¹. -1 The reaction temperature was changed. The results were as follows: Figure 4 , 5 As shown in Figures 6 and 7, the results indicate that using triisobutylene as a raw material and the commercial Amberlyst-15 catalyst, the conversion rate of triisobutylene reached a maximum of 45% at 60℃, while the selectivity for tert-dodecyl mercaptan was 83%. Furthermore, the catalyst exhibited poor stability; stability tests under optimal conditions showed that the stability gradually decreased after 200 hours of reaction, eventually reducing the conversion rate to 20%.

Claims

1. The use of a catalyst, characterized in that, The catalyst is used to synthesize tert-dodecyl mercaptan from triisobutylene; The catalyst is prepared by the following steps: S1: Prepare silicon source mixture A, prepare gallium source mixture B, prepare structure-directing agent mixture C; S2: Add A to C, stir, then add B to obtain a sol-like substance; S3: Add cerium source and / or lanthanum source, add alkyl polyamine solution, stir to obtain mixture D, continue stirring, and dry to obtain powder; S4: Calcined powder to obtain Si-Ga nanomaterials with rare earth element regulation at a single point.

2. The use according to claim 1, characterized in that, The silicon source described in S1 is an oxygen-containing silicon compound and / or a non-oxygen-containing silicon compound; And / or, the gallium source in S1 is one or more of gallium salt, gallate, gallium oxide, and organic gallium; And / or, the structure directing agent described in S1 is a micro-mesoporous structure directing agent.

3. The use according to claim 2, characterized in that, The silicon source mentioned in S1 is one or more of silicon tetrachloride, silica gel, water glass, sodium silicate, silica sol, silica fume, silicic acid, and alkoxysilane; And / or, the gallium source in S1 is one or more of trimethylgallium, sodium gallate, gallium oxide, and gallium nitrate; And / or, the structure directing agent described in S1 is one or more of P123, F127, and C18-6-5; The amount of silicon and gallium source used in S1 makes the Si / Ga mass ratio in the target Si-Ga nanomaterial (2-37):

1. The mass ratio of the structure directing agent to the gallium source in S1 is (15-65):

1.

4. The use according to claim 3, characterized in that, The silicon source mentioned in S1 is one or more of methyl orthosilicate, tetraethyl orthosilicate, and alkoxysilane; And / or, the gallium source in S1 is gallium nitrate; And / or, the structure directing agent described in S1 is C18-6-5; The amount of silicon and gallium source used in S1 makes the Si / Ga mass ratio in the target Si-Ga nanomaterial (5-20):

1. The mass ratio of the structure directing agent to the gallium source in S1 is (35-45):

1.

5. The use according to claim 4, characterized in that, The amount of silicon and gallium source used in S1 makes the Si / Ga mass ratio in the target Si-Ga nanomaterial (8-15):

1.

6. The use according to claim 1, characterized in that, The cerium source and / or lanthanum source mentioned in S3 are water-soluble cerium compounds and / or water-soluble lanthanum compounds; And / or, the alkyl polyamine described in S3 is a water-soluble alkyl polyamine.

7. The use according to claim 6, characterized in that, The cerium source and / or lanthanum source mentioned in S3 is one or more of cerium acetate, cerium nitrate, cerium citrate, lanthanum acetate, lanthanum nitrate, and lanthanum citrate; The amount of cerium source and / or lanthanum source added in S3 makes the mass ratio of Ce and / or La in the target Si-Ga nanomaterial 0.02-4.5%; And / or, the alkyl polyamine described in S3 is one or more of water-soluble alkyl polyamines with an N element number of 2-8; The volume ratio of the alkyl polyamine aqueous solution added to S3 to the original solution is 1:(2-30); The concentration of the alkyl polyamine aqueous solution added to S3 is 0.1-2M.

8. The use according to claim 7, characterized in that, The cerium source and / or lanthanum source mentioned in S3 is cerium nitrate hexahydrate and / or lanthanum nitrate hexahydrate; The amount of cerium source and / or lanthanum source added in S3 makes the mass ratio of Ce and / or La in the target Si-Ga nanomaterial 0.05-2%; And / or, the alkyl polyamine in S3 is hexamethoxymethylmelamine and / or hexamethylenetetramine; The volume ratio of the alkyl polyamine aqueous solution added to S3 to the original solution is 1:(7-17).

9. The use according to claim 8, characterized in that, The amount of cerium source and / or lanthanum source added in S3 makes the mass ratio of Ce and / or La in the target Si-Ga nanomaterial 0.1-1%.

10. The use according to claim 1, characterized in that, The Si-Ga nanomaterial described in S4 has a tetrahedral pyramidal structure.

11. The use according to claim 1, characterized in that, The catalyst is a Si-Ga catalyst with a tetrahedral pyramidal structure and single-point rare earth regulation.

12. The use according to claim 11, characterized in that, The mass ratio of Si to Ga in the catalyst is (2-37):1; The mass ratio of Ce and / or La in the catalyst is 0.02-4.5%.

13. The use according to claim 12, characterized in that, The mass ratio of Si / Ga in the catalyst is (5-20):1; The mass ratio of Ce and / or La in the catalyst is 0.05-2%.

14. The use according to claim 13, characterized in that, The mass ratio of Si to Ga in the catalyst is (8-15):1; The mass ratio of Ce and / or La in the catalyst is 0.1-1%.

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