A method for preparing lilial

Abstract

The application provides a method for preparing lilial. The method is that lilial is synthesized from t-butylbenzene and alpha-methylacrolein under the catalysis of a Ti-K(Na) / F-Meso-SiO2 heterogeneous catalyst. The catalyst used in the application is modified by F element on the carrier, further enhancing the B acid acidity of the catalyst, and the doping of K and / or Na on the Ti metal effectively improves the catalytic activity of the Ti metal. The catalyst used in the application has both B acid and L acid sites, and the two acid active centers synergistically catalyze, so that the process conditions are mild, the reaction time is short, the catalyst is easy to recycle, and the problem of a large amount of waste acid and solid waste generated after the use of traditional catalysts is solved.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis, and specifically relates to a method for preparing lily aldehyde. Background Technology

[0002] lily aldehyde (C 14 H 20 Lily of the valley (O) has a fragrance reminiscent of lily of the valley and lily flowers, with a soft, fresh, and long-lasting aroma. Lily aldehyde is a purely synthetic monomeric fragrance, not yet found in nature. Previously, the formulation of lily of the valley fragrance required large quantities of raw materials such as hydroxycitronellol, lily of the valley aldehyde, neolily of the valley aldehyde, lily of the valley aldehyde, and lily of the valley pyran. However, with the use of hydroxycitronellol restricted by the IFRA, neolily of the valley aldehyde being banned in the EU due to its allergenicity, and lily of the valley pyran being a relatively new product with slow market expansion, lily of the valley aldehyde has become the primary fragrance ingredient for blending lily of the valley fragrances, with an annual market demand exceeding 20,000 tons. The molecular structure of lily of the valley aldehyde is as follows:

[0003]

[0004] Although there are many methods for synthesizing lily aldehyde, the processes and technologies all have some problems and shortcomings. Therefore, it is essential to study a process route that is short in steps, simple in operation, high in yield, low in cost, environmentally friendly, and suitable for industrial production.

[0005] Currently, there are several main synthetic routes for lily aldehyde: The first involves the aldol condensation of benzaldehyde and propionaldehyde, followed by hydrogenation to obtain lily aldehyde. This method has a high yield, but the price of p-tert-butylbenzaldehyde is relatively high, leading to a high cost. The second method uses benzaldehyde and propionaldehyde as raw materials, first condensing them in a dilute alkaline solution to generate α-methylcinnamaldehyde. The aldehyde is then hydrogenated to 2-methylphenylpropanol using a catalyst, followed by alkylation with tert-butyl chloride or isobutylene. Finally, the product is added to a mixture of copper chromite and liquid wax, heated under reduced pressure for dehydrogenation, and fractionated to obtain lily aldehyde. The drawback of this route is the need for a dehydrogenation reaction, which requires high airtightness of the equipment and timely gas transfer. Therefore, the safety risks during scale-up production are relatively high, limiting the industrial application of this route. The third method uses tert-butylbenzene and α-methylpropenal as raw materials to produce lily aldehyde (see the formula below) under low temperature conditions. The catalyst currently used is a complex of titanium tetrachloride and boron trifluoride diethyl ether complex. This method only involves one step in the synthesis of lily aldehyde, and the product obtained has high purity and good quality. However, the current disadvantage of this route is the low yield, and the large amount of Lewis acid used as a catalyst in the reaction also generates a large amount of waste acid in the post-processing, resulting in high costs for waste treatment. Therefore, the third route cannot be industrialized until a new catalyst is developed.

[0006]

[0007] In summary, we need to find a more efficient and green preparation method to improve production efficiency. Based on the advantages and disadvantages of the three process routes mentioned above, the third route has the advantages of a shorter process flow, fewer side reactions, and higher product purity, and has greater potential for future industrialization. The main problem with this method at present lies in the development of a highly efficient catalyst; therefore, finding a more efficient and easily recyclable catalyst is crucial. Summary of the Invention

[0008] The purpose of this invention is to provide a method for preparing lily aldehyde, which has advantages such as mild process conditions (low temperature, atmospheric pressure), short reaction time, and easy catalyst recovery. Under optimal conditions, the conversion rate can reach over 98.0% (based on α-methylpropenal), the yield can reach over 97%, the reaction temperature is 52-55℃, and the reaction pressure is atmospheric pressure.

[0009] To achieve the above-mentioned objectives, the technical solution provided by this invention is as follows:

[0010] A method for preparing lily aldehyde, wherein lily aldehyde is synthesized from tert-butylbenzene and α-methylpropenal under the catalysis of a Ti-K(Na) / F-Meso-SiO2 heterogeneous catalyst.

[0011] In this invention, the Ti-K(Na) / F-Meso-SiO2 catalyst uses F-modified mesoporous silica as a support and K and / or Na-doped Ti metal as the active center.

[0012] In this invention, the catalyst is loaded with Ti metal under alkaline conditions, preferably at a pH of 8-10, more preferably 8.5-9.0. Using ammonia to adjust the pH of the system to 8-10 serves two purposes: firstly, at this pH, the SiO2 surface is negatively charged, providing sites for subsequent Ti metal ion loading; secondly, NH3 coordinates with Ti ions to form a water-soluble complex, preventing Ti ions from precipitating under alkaline conditions.

[0013] In this invention, the step of preparing lily aldehyde is as follows: adding Ti-K(Na) / F-Meso-SiO2 catalyst and α-methylpropenal to tert-butylbenzene, heating and reacting to obtain a reaction solution containing lily aldehyde.

[0014] In this invention, the content of α-methyl acrolein in tert-butylbenzene is 25-40 wt%, preferably 30-36 wt%, more preferably 32-34 wt%; the amount of Ti-K(Na) / F-Meso-SiO2 catalyst is 1-8.0 wt% of the mass of tert-butylbenzene, preferably 2-6 wt%, more preferably 3-4 wt%; the reaction temperature is 45-80℃, preferably 50-60℃, more preferably 52-55℃; the reaction time is 1-3 h, preferably 1.5-2.0 h; and the pressure is atmospheric pressure.

[0015] The Ti-K(Na) / F-Meso-SiO2 catalyst used in this invention has abundant mesoporous channels, providing ample reaction space for the catalytic reaction. Furthermore, the ingenious aspect of this invention lies in utilizing the isoelectric point of silica at approximately 8. By adjusting the pH of the system to 8-10, the silanol groups -Si-OH on the silica surface can be deprotonated and transformed into negatively charged -Si-O groups. - This provides the charge effect for loading positively charged metal cations, and we know that the metal ion Ti... 4+ Precipitation will occur under alkaline conditions, but this can be avoided by coordinating with ammonia. 4+ The precipitation of Ti thus achieves 4+ High dispersion loading of metals is achieved through charge interaction under alkaline conditions, followed by the addition of KF and / or NaF, and negatively charged F... - The support can also be modified by loading it with charge, thereby enhancing the Brønsted acidity and increasing the number of Brønsted acid sites. K / Na ions can be used to dope Ti metal, improving its activity. Rapid solvent evaporation prevents the loss of metal components, achieving effective loading. After calcination, a highly dispersed and active Ti-K(Na) / F-Meso-SiO2 catalyst is obtained. Due to the abundance of Brønsted and Lewis acid sites in the catalyst, the two acidic active centers work synergistically, significantly improving the catalyst's activity.

[0016] Another object of the present invention is to provide a method for preparing Ti-K(Na) / F-Meso-SiO2 catalyst.

[0017] In this invention, the preparation method of the Ti-K(Na) / F-Meso-SiO2 catalyst includes the following steps:

[0018] S1: Ti metal loading: Mesoporous silica is placed in water, ammonia is added to adjust the pH of the system to be alkaline, and Ti salt is added for loading;

[0019] S2: Modified additive support: KF and / or NaF are added to the S1 system for support, solvent removal, drying, and calcination to obtain the target catalyst.

[0020] In this invention, the addition of ammonia in S1 serves two purposes: first, it enables ammonia coordination of Ti ions, preventing premature precipitation of Ti under alkaline conditions and thus ensuring uneven metal dispersion; second, it alters the electroneutrality of the silica channel surface, deprotonating the silanol groups to make them negatively charged, resulting in positively charged Ti(NH3)2. 4+ The ions lay the foundation for achieving highly dispersed Ti loading through charge interaction.

[0021] In this invention, the mass of the S1 mesoporous silica in water is 10-30 wt%, preferably 15-20 wt%, and more preferably 16-17 wt%.

[0022] In this invention, the ammonia water mentioned in S1 is concentrated ammonia water, preferably concentrated ammonia water with a concentration of 26 wt%.

[0023] In this invention, the pH value of the S1 system is adjusted to 8.0-10.0, preferably 8.5-9.0.

[0024] In this invention, the Ti salt in S1 is titanium tetrachloride and / or titanium nitrate, preferably titanium tetrachloride; preferably, the amount of the Ti salt, calculated as TiO2, is 1-5 wt% of the amount of mesoporous silica, more preferably 1.5-3.0 wt%, and more preferably 1.8-2.0 wt%.

[0025] In this invention, the temperature of S1 is 10-40℃, preferably 15-30℃, more preferably 20-22℃; the loading time is 0.5-3h, preferably 2.0-2.5h.

[0026] In this invention, the amount of KF and / or NaF in S2 is 0.1-0.6 wt% of the amount of mesoporous silica, preferably 0.2-0.3 wt%.

[0027] In this invention, the loading time of the modified additive in S2 is 2-5 hours, preferably 3-4 hours.

[0028] In this invention, S2 involves placing the solution in a rotary evaporator flask and rapidly evaporating the solvent by high-temperature vacuum distillation followed by further rotary drying. Preferably, the vacuum distillation temperature is 100-150℃, more preferably 130-140℃, the vacuum degree is 20-50 kPaA, more preferably 30-35 kPaA, and the drying time is 0.5-2.0 h, more preferably 1.0-1.5 h.

[0029] In this invention, the S2 calcination temperature is 400-600℃, preferably 450-500℃; the calcination time is 2-6h, preferably 3-4h.

[0030] This invention utilizes a Ti-K(Na) / F-Meso-SiO2 heterogeneous catalyst prepared in a one-pot process using F-modified mesoporous SiO2 as the support and K and / or Na-doped metallic Ti as the active center. This catalyst efficiently catalyzes the preparation of lily aldehyde from tert-butylbenzene and α-methylpropenal under low-temperature conditions. Compared to conventional catalysts used in this method, the catalyst in this invention, through F modification of the support, further enhances the Brønsted acidity of the catalyst. Simultaneously, K and / or Na doping of the Ti metal effectively improves the catalytic activity of the Ti metal. Because the catalyst used in this invention possesses both Brønsted and Lewis acid sites, the synergistic catalysis of these two acidic active centers significantly improves the reaction efficiency. Furthermore, the catalyst used in this method can be separated and reused through filtration, solving the problem of generating large amounts of waste acid and solid waste after the use of traditional catalysts, and greatly reducing the cost of waste treatment.

[0031] Another object of the present invention is to provide lily aldehyde.

[0032] A type of lily aldehyde, wherein the lily aldehyde is prepared by the method described above, or by catalytic preparation using a catalyst obtained by the catalyst preparation method described above.

[0033] Compared with the prior art, the positive effects of the present invention are as follows:

[0034] (1) The process conditions are mild (low temperature only 52-55℃, normal pressure), the reaction time is short, and the catalyst is easy to recover and reuse. The catalyst used can be separated and reused by filtration, which solves the problem of generating a large amount of waste acid and solid waste after the use of traditional catalysts, and greatly reduces the cost of waste treatment.

[0035] (2) Under optimal conditions, the reaction conversion rate based on α-methylpropenal can reach more than 98.0%, and the yield can reach more than 97%. Specific implementation methods

[0036] The following embodiments are not intended to limit the scope of the present invention. Any modifications or equivalent substitutions made to the present invention without departing from the spirit and scope thereof should be covered within the protection scope of the claims of the present invention.

[0037] All raw materials used in the examples are conventional raw materials in the art, and the purity specifications used are analytical grade or chemically pure. Raw material source information:

[0038] Mesoporous silica, α-methylpropenal, p-tert-butylbenzene, concentrated ammonia, titanium tetrachloride, titanium nitrate, potassium fluoride, and sodium fluoride were all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0039] The following testing method was used:

[0040] Lily aldehyde was analyzed by a GC-9800 chromatograph under the following chromatographic conditions: weakly polar column; initial temperature 100℃, held for 2 min, then programmed to increase to 260℃ at a rate of 10℃ / min, held for 5 min; vaporization chamber temperature 300℃, detection chamber temperature 300℃; FID detection; injection volume 0.2 μL.

[0041] Example 1

[0042] 1) Preparation of Ti-K(Na) / F-Meso-SiO2 catalyst:

[0043] Add 32g (16wt%) of mesoporous silica (Meso-SiO2) to 200g of deionized water, and adjust the pH of the system to 9.0 by adding concentrated ammonia (26wt%) dropwise. Add 1.37g of titanium tetrachloride (1.8wt% of Meso-SiO2 as TiO2), heat to 21℃ and stir for 2.0h. Add 0.064g of NaF (0.2wt% of Meso-SiO2), and continue stirring for 3h. Then place the solution in a rotary evaporator flask, adjust the temperature to 130℃ and the pressure to 30kPa (absolute pressure) to evaporate the solvent to dryness, and then continue rotary evaporation for 1.5h. Finally, take out the solid and place it in a muffle furnace, and calcine it at 500℃ for 4h to obtain the Ti-Na / F-Meso-SiO2 catalyst.

[0044] 2) Preparation of lily aldehyde

[0045] 64g of α-methylpropenal (32wt%) was added to 200g of tert-butylbenzene, followed by 6.0g of Ti-Na / F-Meso-SiO2 (3.0wt%) catalyst. The mixture was placed in a 0.5L reactor, the reaction temperature was raised to 55℃, the reaction pressure was maintained at atmospheric pressure, and the reaction was carried out for 1.5h. The conversion rate of the product obtained after the reaction was calculated to be 98.3% and the yield was 97.3%.

[0046] 3) Catalyst evaluation:

[0047] The conversion and yield data after multiple applications of the catalyst as described in step 2) are as follows:

[0048] Catalyst reuse times Reaction conversion rate / % Yield / % 20 98.1 97.1 40 97.9 96.9 60 97.8 96.8

[0049] As can be seen from the table above, the catalyst still has high catalytic activity after being reused multiple times.

[0050] Example 2

[0051] 1) Preparation of Ti-K / F-Meso-SiO2 catalyst:

[0052] Add 34g (17wt%) of mesoporous silica Meso-SiO2 to 200g of deionized water, add concentrated ammonia (26wt%) dropwise to adjust the pH of the system to 8.5, add 2.52g of titanium nitrate (2.0wt% of Meso-SiO2 as TiO2), heat to 20℃ and stir for 2.5h, add 0.102g of KF (0.3wt% of Meso-SiO2), continue stirring for 4h, then place the solution in a rotary evaporator flask, adjust the temperature to 140℃ and the pressure to 35kPa (absolute pressure) to evaporate the solvent to dryness, and then continue rotary evaporation for 1.0h. Finally, take out the solid and place it in a muffle furnace, calcine at 450℃ for 3h to obtain the Ti-K / F-Meso-SiO2 catalyst.

[0053] 2) Preparation of lily aldehyde:

[0054] 68g of α-methylpropenal (34wt%) was added to 200g of tert-butylbenzene, followed by 8.0g of Ti-K / F-Meso-SiO2 (4.0wt%) catalyst. The mixture was placed in a 0.5L reactor, the reaction temperature was raised to 52℃, the reaction pressure was maintained at atmospheric pressure, and the reaction was carried out for 2.0h. The conversion rate of the product obtained after the reaction was calculated to be 98.1%, and the yield was 97.1%.

[0055] Example 3

[0056] 1) Preparation of Ti-Na / F-Meso-SiO2 catalyst:

[0057] Add 20g (10wt%) of mesoporous silica Meso-SiO2 to 200g of deionized water, and adjust the pH of the system to 8 by adding concentrated ammonia (26wt%) dropwise. Add 2.37g of titanium tetrachloride (5.0wt% of Meso-SiO2 as TiO2), heat to 30℃ and stir for 0.5h. Add 0.12g of NaF (0.6wt% of Meso-SiO2), and continue stirring for 2h. Then place the solution in a rotary evaporator flask, adjust the temperature to 150℃ and the pressure to 20kPa (absolute pressure) to evaporate the solvent to dryness, and then continue rotary evaporation for 0.5h. Finally, take out the solid and place it in a muffle furnace, and calcine it at 400℃ for 6h to obtain the Ti-Na / F-Meso-SiO2 catalyst.

[0058] 2) Preparation of lily aldehyde:

[0059] 50g of α-methylpropenal (25wt%) was added to 200g of tert-butylbenzene, followed by 4.0g of Ti-Na / F-Meso-SiO2 (2.0wt%) catalyst. The mixture was placed in a 0.5L reactor, the reaction temperature was raised to 80℃, the reaction pressure was maintained at atmospheric pressure, and the reaction was carried out for 1.0h. The conversion rate of the product obtained after the reaction was calculated to be 95.6%, and the yield was 94.6%.

[0060] Example 4

[0061] 1) Preparation of Ti-K / F-Meso-SiO2 catalyst:

[0062] Add 40g (20wt%) of mesoporous silica Meso-SiO2 to 200g of deionized water, add concentrated ammonia (26wt%) dropwise to adjust the pH of the system to 10.0, add 1.48g of titanium nitrate (1.0wt% of the mass of Meso-SiO2 as TiO2), heat to 10℃ and stir for 3.0h, add 0.04g of KF (0.1wt% of the mass of Meso-SiO2), continue stirring for 5h, then place the solution in a rotary evaporator flask, adjust the temperature to 100℃ and the pressure to 45kPa (absolute pressure) to evaporate the solvent to dryness, and then continue rotary evaporation for 2.0h. Finally, take out the solid and place it in a muffle furnace, calcine at 550℃ for 2h to obtain the Ti-K / F-Meso-SiO2 catalyst.

[0063] 2) Preparation of lily aldehyde:

[0064] 72g of α-methylpropenal (36wt%) was added to 200g of tert-butylbenzene, followed by 16.0g of Ti-K / F-Meso-SiO2 (8.0wt%) catalyst. The mixture was placed in a 0.5L reactor, the reaction temperature was raised to 45℃, the reaction pressure was maintained at atmospheric pressure, and the reaction was carried out for 3.0h. The conversion rate of the product obtained after the reaction was calculated to be 90.1%, and the yield was 89.2%.

[0065] Example 5

[0066] 1) Preparation of Ti-Na / F-Meso-SiO2 catalyst:

[0067] Add 60g (30wt%) of mesoporous silica Meso-SiO2 to 200g of deionized water, and adjust the pH of the system to 9.5 by adding concentrated ammonia (26wt%) dropwise. Add 4.27g of titanium tetrachloride (3.0wt% of Meso-SiO2 as TiO2), heat to 40℃ and stir for 2.0h. Add 0.24g of NaF (0.4wt% of Meso-SiO2), and continue stirring for 4h. Then place the solution in a rotary evaporator flask, adjust the temperature to 120℃ and the pressure to 50kPa (absolute pressure) to evaporate the solvent to dryness, and then continue rotary evaporation for 2.0h. Finally, take out the solid and place it in a muffle furnace, and calcine it at 600℃ for 5h to obtain the Ti-Na / F-Meso-SiO2 catalyst.

[0068] 2) Preparation of lily aldehyde:

[0069] 80g of α-methylpropenal (40wt%) was added to 200g of tert-butylbenzene, followed by 12.0g of Ti-K / F-Meso-SiO2 (6.0wt%) catalyst. The mixture was placed in a 0.5L reactor, the reaction temperature was raised to 60℃, the reaction pressure was maintained at atmospheric pressure, and the reaction was carried out for 1.0h. The conversion rate of the product obtained after the reaction was calculated to be 96.4%, and the yield was 95.4%.

[0070] Example 6

[0071] 1) Preparation of Ti-K / F-Meso-SiO2 catalyst:

[0072] Add 30g (15wt%) of mesoporous silica Meso-SiO2 to 200g of deionized water, add concentrated ammonia (26wt%) dropwise to adjust the pH of the system to 8.0, add 1.67g of titanium nitrate (1.5wt% of Meso-SiO2 as TiO2), heat to 15℃ and stir for 2.0h, add 0.06g of KF (0.4wt% of Meso-SiO2), continue stirring for 3h, then place the solution in a rotary evaporator flask, adjust the temperature to 110℃ and the pressure to 25kPa (absolute pressure) to evaporate the solvent to dryness, and then continue rotary evaporation for 0.5h. Finally, take out the solid and place it in a muffle furnace, calcine at 520℃ for 2h to obtain the Ti-K / F-Meso-SiO2 catalyst.

[0073] 2) Preparation of lily aldehyde:

[0074] 60g of α-methylpropenal (30wt%) was added to 200g of tert-butylbenzene, followed by 2.0g of Ti-K / F-Meso-SiO2 (1.0wt%) catalyst. The mixture was placed in a 0.5L reactor, the reaction temperature was raised to 70℃, the reaction pressure was maintained at atmospheric pressure, and the reaction was carried out for 3.0h. The conversion rate of the product obtained after the reaction was calculated to be 97.0%, and the yield was 96.0%.

[0075] Comparative Example 1

[0076] Compared with Example 1, the only difference is that the catalyst is replaced with an equal mass of titanium tetrachloride, a commonly used catalyst in the prior art.

[0077] The above-described catalyst was used to prepare lily aldehyde, with other procedures identical to those in Example 1. Analysis of the product after the reaction yielded a conversion rate of 65% and a lily aldehyde yield of 54%.

[0078] Comparative Example 2

[0079] Compared with Example 1, the only difference is that NaF or KF is not added during the catalyst preparation process, and catalyst reuse is not performed.

[0080] Conyaldehyde was prepared using an equal mass of the catalyst described above, with other procedures identical to those in Example 1. Analysis of the product after the reaction yielded a conversion rate of 81% and a convexaldehyde yield of 72%.

[0081] Comparative Example 3

[0082] The only difference from Example 1 is that the pH of the reaction system is not adjusted during the preparation of the Ti-K / F-Meso-SiO2 catalyst in Example 1.

[0083] The other processes were the same as in Example 1. Analysis of the product after the reaction yielded a conversion rate of 79% and a lily aldehyde yield of 56%.

[0084] The results of the above examples and comparative examples show that the method for preparing lily aldehyde of the present invention has mild process conditions, short reaction time, and easy catalyst recycling, and also solves the problem of generating a large amount of waste acid and solid waste after the use of traditional catalysts.

Claims

1. A method for preparing lily aldehyde, characterized in that, The method involves synthesizing lily aldehyde from tert-butylbenzene and α-methylpropenal under the catalysis of a Ti-K(Na) / F-Meso-SiO2 heterogeneous catalyst. The Ti-K(Na) / F-Meso-SiO2 catalyst uses F-modified mesoporous silica as a support and K and / or Na-doped Ti metal as the active center. The catalyst is prepared by a method comprising the following steps: S1: Ti metal loading: Mesoporous silica is placed in water, ammonia is added to adjust the pH of the system to be alkaline, and Ti salt is added for loading; S2: Modified additive support: KF and / or NaF are added to the S1 system for support, solvent removal, drying, and calcination to obtain the target catalyst.

2. The method for preparing lily aldehyde according to claim 1, characterized in that, The catalyst is supported on Ti metal under alkaline conditions.

3. The method for preparing lily aldehyde according to claim 2, characterized in that, The catalyst is loaded with Ti metal at a pH of 8-10.

4. The method for preparing lily aldehyde according to claim 3, characterized in that, The catalyst is loaded with Ti metal at a pH of 8.5-9.

0.

5. The method for preparing lily aldehyde according to claim 1 or 2, characterized in that, The steps for preparing lily aldehyde are as follows: Ti-K(Na) / F-Meso-SiO2 catalyst and α-methylpropenal are added to tert-butylbenzene, and the mixture is heated to react, resulting in a reaction solution containing lily aldehyde.

6. The method for preparing lily aldehyde according to claim 5, characterized in that, The α-methylpropenal content in tert-butylbenzene is 25-40 wt%; the amount of the Ti-K(Na) / F-Meso-SiO2 catalyst is 1-8.0 wt% of the mass of tert-butylbenzene. And / or, the reaction temperature is 45-80℃; the reaction time is 1-3h; and the pressure is atmospheric pressure.

7. The method for preparing lily aldehyde according to claim 6, characterized in that, The α-methylpropenal content in tert-butylbenzene is 30-36 wt%; the amount of the Ti-K(Na) / F-Meso-SiO2 catalyst is 2-6 wt% of the mass of tert-butylbenzene. And / or, the reaction temperature is 50-60℃; the reaction time is 1.5-2.0h.

8. The method for preparing lily aldehyde according to claim 7, characterized in that, The α-methylpropenal content in tert-butylbenzene is 32-34 wt%; the amount of the Ti-K(Na) / F-Meso-SiO2 catalyst is 3-4 wt% of the mass of tert-butylbenzene. And / or, the reaction temperature is 52-55℃.

9. A method for preparing a Ti-K(Na) / F-Meso-SiO2 catalyst, wherein the catalyst is the catalyst used in the method according to any one of claims 1-8, characterized in that, The catalyst preparation method includes the following steps: S1: Ti metal loading: Mesoporous silica is placed in water, ammonia is added to adjust the pH of the system to be alkaline, and Ti salt is added for loading; S2: Modified additive support: KF and / or NaF are added to the S1 system for support, solvent removal, drying, and calcination to obtain the target catalyst.

10. The catalyst preparation method according to claim 9, characterized in that, The mass of the S1 mesoporous silica in water is 10-30 wt%; And / or, the ammonia solution described in S1 is concentrated ammonia solution; And / or, S1 adjusts the pH of the system to 8.0-10.0; And / or, the Ti salt in S1 is titanium tetrachloride and / or titanium nitrate; And / or, the temperature of S1 is 10-40℃; the loading time is 0.5-3h.

11. The catalyst preparation method according to claim 10, characterized in that, The mass of the S1 mesoporous silica in water is 15-20 wt%; And / or, the ammonia solution described in S1 is a concentrated ammonia solution with a concentration of 26 wt%; And / or, S1 adjusts the pH of the system to 8.5-9.0; And / or, the Ti salt in S1 is titanium tetrachloride; The Ti salt, calculated as TiO2, is used in an amount of 1-5 wt% of the mesoporous silica. And / or, the temperature of S1 is 15-30℃; the loading time is 2.0-2.5h.

12. The catalyst preparation method according to claim 11, characterized in that, The mass of the S1 mesoporous silica in water is 16-17 wt%; The Ti salt, calculated as TiO2, is used in an amount of 1.5-3.0 wt% of the mesoporous silica. And / or, the temperature of S1 is 20-22℃.

13. The catalyst preparation method according to claim 12, characterized in that, The amount of Ti salt in S1, calculated as TiO2, is 1.8-2.0 wt% of the amount of mesoporous silica.

14. The catalyst preparation method according to claim 9, characterized in that, The amount of KF and / or NaF in S2 is 0.1-0.6 wt% of the amount of mesoporous silica; And / or, the loading time of the modified additives described in S2 is 2-5 hours; And / or, S2 places the solution in a rotary evaporation flask and rapidly evaporates the solvent by high-temperature vacuum distillation and then performs further rotary drying; And / or, the S2 calcination temperature is 400-600℃; the calcination time is 2-6h.

15. The catalyst preparation method according to claim 14, characterized in that, The amount of KF and / or NaF in S2 is 0.2-0.3 wt% of the amount of mesoporous silica; And / or, the loading time of the modified additives described in S2 is 3-4 hours; The vacuum distillation temperature is 100-150℃, the vacuum degree is 20-50 kPaA, and the drying time is 0.5-2.0 h. And / or, the S2 calcination temperature is 450-500℃; the calcination time is 3-4h.

16. The catalyst preparation method according to claim 15, characterized in that, The vacuum distillation temperature in S2 is 130-140℃, the vacuum degree is 30-35kPaA, and the drying time is 1.0-1.5h.

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