Composite catalyst, preparation method thereof and application of composite catalyst in synthesis of pseudo ionone compound

Abstract

The invention relates to a composite catalyst, a preparation method thereof and application of the composite catalyst in synthesis of pseudo ionone compounds. The composite catalyst comprises a carrier and an active component loaded on the carrier, the active component comprises a complex formed by a modifier and active metal atoms; the modifier comprises a methoxy silane compound; the active metal atoms comprise transition metal; the transition metal comprises any one or a combination of at least two of iron, copper, nickel, zirconium or molybdenum, and the carrier comprises a molecular sieve. The composite catalyst provided by the invention is used for preparing the pseudo ionone compound through aldol condensation reaction, has the advantages of mild reaction conditions, high reaction yield, simple post-treatment and the like, and is beneficial to industrial application.

Description

Technical Field

[0001] The present invention relates to the technical field of fine chemicals, and particularly relates to a composite catalyst, a preparation method thereof, and an application thereof in the synthesis of pseudo-ionone compounds. Background Art

[0002] Both ionone and methyl ionone are products of the ionone series and are widely used in the fragrance and flavor field.

[0003] Ionone has a special aroma at room temperature and is an extremely important fragrance, which can be applied to cosmetics, food and beverages. Its synthesis is produced by a two-step method: First, citral and acetone undergo an aldol condensation reaction catalyzed by a base catalyst to obtain pseudo-ionone; then a cyclization reaction occurs under acid catalysis to obtain ionone.

[0004] Methyl ionone is an important synthetic fragrance with a unique aroma quality. Its aroma is mellow and long-lasting, and it can be well blended with many floral and woody fragrance raw materials. It can be used as a blending agent, modifier and basic fragrance raw material in fragrances. Methyl ionone is generally synthesized by two-step reactions: First, citral and butanone undergo a condensation reaction under alkaline conditions to obtain an intermediate pseudo-methyl ionone, which has two isomers, namely pseudo-n-methyl ionone and pseudo-isomethyl ionone, and then a cyclization reaction occurs under acidic conditions to generate methyl ionone.

[0005] It can be seen that in the synthesis processes of both ionone and methyl ionone, they need to be obtained by reacting citral with the corresponding ketone raw materials. However, taking the synthesis of pseudo-ionone, the key intermediate of ionone, as an example, in the process of aldol condensation to synthesize the target product, there are multiple carbon-carbon double bonds and active carbonyl groups in the molecules of the reactants citral, acetone and the target product pseudo-ionone, all of which show certain activities, and side reactions will occur to varying degrees during the reaction, resulting in a decrease in the yield and selectivity of pseudo-ionone. Therefore, in industrial production, a large excess of acetone is generally added to reduce the self-polymerization and copolymerization between citral and pseudo-ionone. After the reaction, the excess acetone generally needs to be recovered, resulting in serious waste of energy. In addition, under these reaction conditions, acetone itself will undergo an equilibrium reaction to form diacetone alcohol. Especially under alkaline conditions, the equilibrium reaction rate of acetone to form diacetone alcohol is very fast. At different temperatures, the equilibrium composition of acetone and diacetone alcohol is different. Under the process conditions for producing pseudo-ionone, generally more than 5% of acetone is converted into diacetone alcohol, further leading to waste of raw materials.

[0006] At present, the commonly used base catalysts for aldol condensation reactions include liquid bases, solid bases, and basic ionic liquids, etc. The main existing problems include: (1) Inorganic base solutions that are difficult to separate are used in the synthesis process. It is very difficult to separate them from the products after the reaction, and they cannot be reused, making the post-treatment difficult; (2) A large amount of strong bases are used as catalysts during the reaction process, generating a large amount of three wastes, seriously polluting the environment. At the same time, these bases also cause serious corrosion to the equipment; (3) The reaction time is long, there are many side reactions during the reaction process, the post-treatment purification and separation of the products are difficult, and the requirements for the reaction equipment are high; (4) Basic catalysts show high reaction activity in aldol condensation reactions. However, since the aldol condensation reaction process is usually accompanied by dehydration, it is not conducive to the stability of basic catalysts in the presence of water.

[0007] Therefore, providing a catalyst for synthesizing pseudo-ionone compounds intermediates in aldol condensation reactions is of great significance for improving the yield of ionone series products and promoting their industrial development. Summary of the Invention

[0008] Aiming at the above problems, the purpose of the present invention is to provide a composite catalyst, its preparation method and its application in the synthesis of pseudo-ionone compounds. Compared with the prior art, the composite catalyst provided by the present invention for preparing pseudo-ionone compounds by aldol condensation reaction has the advantages of mild reaction conditions, high reaction yield and simple post-treatment, which is conducive to industrial application.

[0009] To achieve the purpose of this invention, the present invention adopts the following technical solutions:

[0010] In the first aspect, the present invention provides a composite catalyst, which includes a carrier and an active component supported on the carrier;

[0011] The active component includes a complex formed by a modifier and an active metal atom;

[0012] The modifier includes a methoxysilane compound;

[0013] The active metal atom includes a transition metal;

[0014] The transition metal includes any one or a combination of at least two of iron, copper, nickel, zirconium or molybdenum;

[0015] The carrier includes molecular sieve.

[0016] The composite catalyst provided by the present invention is composed of active metal ions, silane modifiers, and molecular sieve carriers. Among them, the silane contains oxygen atoms with coordination activity, which form a three-dimensional multi-core metal complex analogue through coordination bonding and assembly with the active metal and metal atoms in the carrier, and the catalyst of the present invention is formed by loading it on the carrier. The multi-core metal complex analogue provides more high-activity sites, making the catalyst have high catalytic activity and selectivity; the silane can reduce the surface tension of the carrier, enabling the carrier and the active component to form good contact, strengthening the binding strength between the active component and the carrier, inhibiting the aggregation of the active component, reducing the loss of the active component during the reaction process, and inhibiting the deactivation of the catalyst, realizing the recycling of the catalyst, without the need to frequently replace the catalyst, further reducing the production cost. Finally, the composite catalyst provided by the present invention is used for the formation of pseudoionone compounds from citral and ketones. Not only are the reaction conditions mild, but also the selectivity and yield are greatly improved. The feeding ratio of acetone or butanone can be reduced to the normal range, and the reaction can be carried out without a large excess of ketones, reducing the separation energy consumption after the reaction, improving the utilization rate of raw materials, and the structure of the catalyst is stable, the active component is not easily lost, the catalyst can be recycled, and it has broad application prospects.

[0017] Preferably, the mass ratio of the modifier to the active metal atom is (2.0 - 10.0):1. For example, it can be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable; the mass ratio of the active metal atom to the carrier is (0.03 - 0.09):1. For example, it can be 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, or 0.09:1, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0018] In the present invention, by preferably controlling the mass ratio of the modifier to the active metal atom, the silane and the active metal can reach the best coordination state. If the amount of the modifier is too low, the active metal cannot be fully coordinated, resulting in a decrease in the activity of the catalyst; if the amount of the modifier is too much, it will lead to waste of the modifier and poor economy.

[0019] By preferably controlling the mass ratio of the active metal atom to the carrier in the present invention, the metal can reach the best loading amount on the carrier. If the amount of metal atoms is too small, the number of active sites of the catalyst is small, and the activity and selectivity of the catalyst are poor; if the amount of metal atoms is too much, the carrier cannot fully support it, which not only causes waste of metal, but also partially covers the active sites, resulting in a decrease in the selectivity of the catalyst.

[0020] Preferably, the methoxysilane compound includes any one or a combination of at least two of (3-mercaptopropyl)trimethoxysilane (CAS No.: 4420-74-0; Mw: 196.34), trimethoxy[3-(phenylamino)propyl]silane (CAS No.: 3068-76-6; Mw: 255.39), 3-(methacryloyloxy)propyltrimethoxysilane (CAS No.: 2530-85-0; Mw: 248.35), (3-chloropropyl)trimethoxysilane (CAS No.: 2530-87-2; Mw: 198.72), trimethoxy[3-(methylamino)propyl]silane (CAS No.: 3069-25-8; Mw: 193.32), propyltrimethoxysilane (CAS No.: 1067-25-0; Mw: 164.27), allyltrimethoxysilane (CAS No.: 2551-83-9; Mw: 162.26), trimethoxy(3,3,3-trifluoropropyl)silane (CAS No.: 429-60-7; Mw: 218.25), or (3-methoxypropyl)trimethoxysilane (CAS No.: 33580-59-5; Mw: 194.30).

[0021] Preferably, the molecular sieve includes any one or a combination of at least two of ZSM-5, Hβ, Sn-β, SAPO-18, SAPO-34, SAPO-11, or SAPO-5.

[0022] In the present invention, by preferably adopting the above molecular sieve, it is because the above molecular sieve is a mesoporous or microporous molecular sieve, enabling the active metal to be distributed on the surface of the carrier as much as possible, providing more high-activity sites, fully activating the reaction substrate, enabling the reaction to be completed quickly on the surface of the catalyst, and enabling the generated product to leave the catalyst as soon as possible, preventing overreaction, and contributing to improving the selectivity of the reaction.

[0023] In a second aspect, the present invention provides a preparation method of the composite catalyst described in the first aspect of the present invention, and the preparation method includes the following steps:

[0024] (1) Mix an active metal salt and a modifier in a solvent, and then carry out a reaction to obtain a mixed solution;

[0025] (2) Mix the mixed solution obtained in step (1) and a carrier for adsorption to obtain a catalyst solution;

[0026] (3) Remove the solvent from the catalyst solution obtained in step (2) to obtain a catalyst.

[0027] In the preparation method provided by the present invention, first, an active metal salt reacts with a modifier. During the reaction, silane coordinates with active metal atoms to obtain an active ingredient. Then, a carrier is used to adsorb the active ingredient. At the same time of adsorption, silane also coordinates with metal atoms in the carrier. Compared with directly mixing the active metal salt, the modifier and the carrier, the present invention can fully generate the active ingredient while preventing the generation reaction of the active ingredient from competing with the adsorption reaction of the carrier. Finally, the catalyst is obtained by removing the solvent. The catalyst obtained by using the preparation method of the present invention has good catalytic activity and selectivity, thereby being able to improve the yield of pseudo-ionone compounds and the utilization rate of raw materials, and the active ingredient is not easily lost, and can be recycled.

[0028] In the present invention, the active metal salt can adopt common salts in the art containing the active metal atom, for example, it can be a chloride salt, a sulfate salt, a nitrate salt, etc.

[0029] In the present invention, the solvent can adopt common solvents in the art, for example, it can be deionized water.

[0030] Preferably, the temperature of the reaction in step (1) is 80 - 120 °C, for example, it can be 80 °C, 85 °C, 90 °C, 95 °C, 100 °C, 105 °C, 110 °C, 105 °C or 120 °C, but not limited to the listed values, and other unlisted values within the numerical range are equally applicable; the reaction time is 2 - 6 h, for example, it can be 2 h, 3 h, 4 h, 5 h or 6 h, but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0031] Preferably, stirring is carried out during the adsorption process in step (2); the stirring time is 4 - 8 h, for example, it can be 4 h, 5 h, 6 h, 7 h or 8 h, but not limited to the listed values, and other unlisted values within the numerical range are equally applicable; the adsorption temperature is 40 - 80 °C, for example, it can be 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C or 80 °C, but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0032] In the present invention, by preferably controlling the adsorption temperature in step (2) within a specific range, it is because adsorption and desorption occur simultaneously, and by controlling the adsorption temperature, it is possible to avoid the deterioration of the adsorption effect caused by too high a temperature.

[0033] Preferably, the method for removing the solvent in step (3) includes any one or a combination of at least two of rotary evaporation, filtration or evaporation to dryness.

[0034] In the present invention, the rotary evaporation, filtration or evaporation to dryness are conventional methods in the art, aiming to remove the solvent and can be carried out under conventional operating conditions.

[0035] As a preferred technical solution of the second aspect of the present invention, the preparation method includes the following steps:

[0036] (1) Mix the active metal salt and the modifier in a solvent, and then react at 80 - 120 °C for 2 - 6 h to obtain a mixed solution;

[0037] (2) Mix the mixed solution obtained in step (1) with the carrier, adsorb at 40 - 80 °C and stir for 4 - 8 h to obtain a catalyst solution;

[0038] (3) Rotary evaporate the solvent from the catalyst solution obtained in step (2) to obtain a catalyst.

[0039] In the third aspect, the present invention provides an application of the composite catalyst as described in the first aspect of the present invention, and the composite catalyst is used for synthesizing pseudo - ionone compounds.

[0040] The composite catalyst provided by the present invention is used in the aldol condensation reaction to synthesize pseudo - ionone compounds, which is beneficial to improving the yield of subsequent ionone series products, reducing energy consumption, saving raw material costs, and plays an important role in the industrial development of ionone series products.

[0041] Preferably, the preparation method of the pseudo - ionone compounds includes: carrying out an aldol condensation reaction on citral and ketones under the action of the composite catalyst to obtain pseudo - ionone compounds; the ketones include acetone and / or butanone; the molar ratio of the ketones to citral is (1 - 3):1, for example, it can be 1:1, 1.5:1, 2:1, 2.5:1 or 3:1, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable; the mass ratio of the composite catalyst to citral is (0.01 - 0.1):1, for example, it can be 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1 or 0.1:1, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0042] It should be noted that, compared with using a conventional catalyst which requires a large excess of the ketone substrate, generally controlling the molar ratio of the ketones to citral to be (10 - 15):1, which leads to side reactions and increased energy consumption for recovery, using the composite catalyst provided by the present invention can greatly reduce the dosage of the ketone substrate, reduce side reactions, and improve the yield of pseudo - ionone compounds.

[0043] Preferably, the temperature of the aldol condensation reaction is 60 - 120°C, for example, it can be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0044] Preferably, the time of the aldol condensation reaction is 1.0 - 6.0 h, for example, it can be 1 h, 2 h, 3 h, 4 h, 5 h or 6 h. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The composite catalyst provided by the present invention has high reaction activity and selectivity, and has a stable structure. The active components are not easily lost, enabling the recycling of the catalyst. There is no need to frequently replace the catalyst. Moreover, the raw materials are cheap and easily available, and the operation is simple, which is conducive to continuous industrial production and significantly improves the equipment utilization rate.

[0047] (2) The composite catalyst provided by the present invention avoids the corrosion of equipment by conventional strong alkaline catalysts. The raw materials are cheap and easily available, and the operation is simple, which is conducive to continuous industrial production and significantly improves the equipment utilization rate.

[0048] (3) The composite catalyst provided by the present invention is used for the aldol condensation reaction of citral with acetone or butanone to synthesize pseudoionone compounds. The reaction conditions are mild, the reaction yield is high. Compared with conventional catalysts, it can greatly reduce the feeding ratio of ketones, reduce the occurrence of side reactions, reduce the separation energy consumption after the reaction, and improve the utilization rate of raw materials.

[0049] (4) Using the composite catalyst provided by the present invention, under relatively optimal conditions, taking the synthesis of pseudoionone as an example, the conversion rate of citral reaches more than 97.1%, and the selectivity of pseudoionone reaches more than 98.1%, and no self-polymerization product of citral and acetone condensation product is produced; taking the synthesis of pseudomethylionone as an example, the conversion rate of citral reaches more than 99.1%, and the selectivity of pseudomethylionone reaches more than 98.8%, and no self-polymerization product of citral and acetone condensation product is produced; the obtained catalyst can be recycled. Taking the composite catalyst provided in Example 8 as an example, after being recycled 10 times, the conversion rate of citral can still reach more than 99.1%, and the selectivity of pseudoionone can still reach more than 99.2%. Specific embodiments

[0050] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0051] Example 1

[0052] This example provides a composite catalyst. The composite catalyst includes a carrier and an active component supported on the carrier. The active component includes a complex formed by a modifier and an active metal salt. The modifier is (3-mercaptopropyl)trimethoxysilane, the active metal atom contained in the active metal salt is Fe, the mass ratio of the modifier to the active metal atom is 8:1, the mass ratio of the active metal atom to the carrier is 0.05:1, and the carrier is a SAPO-34 carrier.

[0053] This example also provides a preparation method of the above composite catalyst. The preparation method includes the following steps:

[0054] Mix FeCl3·6H2O (2.420 g, 8.953 mmol) and (3-mercaptopropyl)trimethoxysilane (4.0 g, 20.3728 mmol) in 20 mL of deionized water, and then carry out a constant temperature stirring reaction at 100 °C for 4 h to obtain a mixed solution; cool down to 60 °C, add 10 g of SAPO-34 carrier, carry out adsorption and stirring at 60 °C for 6 h to obtain a catalyst solution; then rotary evaporate to remove water to obtain a solid catalyst.

[0055] Examples 2-9

[0056] Examples 2-9 respectively provide a composite catalyst. The difference compared with Example 1 is only that the modifier is sequentially replaced with trimethoxy[3-(phenylamino)propyl]silane, 3-(methacryloyloxy)propyltrimethoxysilane, (3-chloropropyl)trimethoxysilane, trimethoxy[3-(methylamino)propyl]silane, propyltrimethoxysilane, allyltrimethoxysilane, trimethoxy(3,3,3-trifluoropropyl)silane, (3-methoxypropyl)trimethoxysilane.

[0057] Examples 2-9 also respectively provide a preparation method of a composite catalyst. The difference compared with Example 1 is only that the modifier in Example 1 is respectively replaced with trimethoxy[3-(phenylamino)propyl]silane, 3-(methacryloyloxy)propyltrimethoxysilane, (3-chloropropyl)trimethoxysilane, trimethoxy[3-(methylamino)propyl]silane, propyltrimethoxysilane, allyltrimethoxysilane, trimethoxy(3,3,3-trifluoropropyl)silane, (3-methoxypropyl)trimethoxysilane, and the mass of the modifier is kept unchanged.

[0058] Examples 10 - 16

[0059] Examples 10 - 16 respectively provide a method for preparing a composite catalyst, which is only different from Example 8 in that FeCl3·6H2O (2.420 g, 8.953 mmol) in Example 8 is sequentially replaced with Fe(NO3)3·9H2O (3.617 g, 8.953 mmol), FeSO4·7H2O (2.489 g, 8.953 mmol), Fe(acac)3 (3.162 g, 8.953 mmol), FeCl3 (1.452 g, 8.953 mmol), CuSO4·5H2O (1.965 g, 7.868 mmol), Zr(NO3)4·5H2O (2.353 g, 5.481 mmol), (NH4)6Mo7O 24 ·4H2O (0.920 g, 5.212 mmol).

[0060] Examples 17 - 23

[0061] Examples 17 - 23 respectively provide a method for preparing a composite catalyst, which is only different from Example 8 in that the SAPO - 34 support in Example 8 is sequentially replaced with a ZSM - 5 support, a SAPO - 11 support, an Hβ support, a Sn - β support, a SAPO - 18 support, a SAPO - 5 support, and zeolite, while keeping the mass of the support unchanged.

[0062] Examples 24 - 28

[0063] Examples 24 - 28 respectively provide a composite catalyst, which is only different from Example 8 in that the mass ratio of the active metal element to the support is sequentially 0.03:1, 0.07:1, 0.09:1, 0.01:1, 0.12:1.

[0064] Examples 24 - 28 also respectively provide a method for preparing a composite catalyst, which is only different from Example 8 in that the addition amounts of the active metal salt and the modifier are adjusted as shown in Table 1.

[0065] Table 1

[0066]

[0067] Examples 29 - 34

[0068] Examples 29 - 34 respectively provide a composite catalyst, which is only different from Example 8 in that the mass ratio of the modifier to the active metal atoms is sequentially 2:1, 4:1, 6:1, 10:1, 1:1, and 12:1.

[0069] Example 29 - 34 also provides a preparation method of a composite catalyst respectively. The difference compared with Example 8 is only to adjust the addition amounts of the active metal salt and the modifier, as shown in Table 2.

[0070] Table 2

[0071]

[0072] Examples 35 - 42

[0073] Examples 35 - 42 provide a preparation method of a composite catalyst respectively. The difference compared with Example 8 is only to adjust the temperature and time of the reaction between the active metal salt and the modifier, and to adjust the temperature and time of the carrier for adsorption and stirring, as shown in Table 3.

[0074] Table 3

[0075]

[0076] Comparative Example 1

[0077] This comparative example provides a preparation method of a composite catalyst. The difference between the preparation method and Example 8 is that no modifier is added. The preparation method includes the following steps:

[0078] Mix FeCl3·6H2O (2.420 g, 8.953 mmol) in 20 mL of deionized water, and then carry out a constant - temperature stirring reaction at 100 °C for 4 h to obtain a mixed solution; cool down to 60 °C, add 10 g of SAPO - 34 carrier, and carry out adsorption and stirring at 60 °C for 6 h to obtain a catalyst solution; then rotary evaporate to remove the water to obtain the solid catalyst of Comparative Example 1.

[0079] Comparative Example 2

[0080] This comparative example provides a preparation method of a composite catalyst. The difference between the preparation method and Example 8 is that no carrier is added. The preparation method includes the following steps:

[0081] Mix FeCl3·6H2O (2.420 g, 8.953 mmol) and trimethoxy(3,3,3 - trifluoropropyl)silane (4.0 g, 18.3276 mmol) in 20 mL of deionized water, and then carry out a constant - temperature stirring reaction at 100 °C for 4 h to obtain a mixed solution; cool down to 60 °C and carry out constant - temperature stirring for 6 h to obtain the catalyst solution of Comparative Example 2.

[0082] Comparative Example 3

[0083] This comparative example provides a preparation method of a composite catalyst. The preparation method includes the following steps:

[0084] Mix FeCl3·6H2O (2.420 g, 8.953 mmol) and trimethoxy(3,3,3-trifluoropropyl)silane (4.0 g, 18.3276 mmol) in 20 mL of deionized water, then carry out a constant-temperature stirring reaction at 100 °C for 4 h to obtain a mixed solution; cool down to 60 °C, add 10 g of SAPO-34 support, and stir at a constant temperature for 6 h, then filter, and then calcine at 300 °C to obtain the catalyst of Comparative Example 3.

[0085] Comparative Example 4

[0086] This comparative example provides a preparation method of a composite catalyst, and the preparation method includes the following steps:

[0087] Mix FeCl3·6H2O (2.420 g, 8.953 mmol), trimethoxy(3,3,3-trifluoropropyl)silane (4.0 g, 18.3276 mmol) and 10 g of SAPO-34 support in 20 mL of deionized water, then carry out a constant-temperature stirring reaction at 100 °C for 4 h, then cool down to 60 °C and stir at a constant temperature for 6 h, and then remove the water by rotary evaporation to obtain the catalyst of Comparative Example 4.

[0088] Application Examples 1 - 42

[0089] These Application Examples 1 - 42 respectively provide an application of a composite catalyst. The composite catalyst sequentially adopts the composite catalysts provided in the above Examples 1 - 42 and is used for preparing pseudoionone. The preparation method includes:

[0090] Add citral (0.5 mol, 76.12 g), acetone (1.0 mol, 58.08 g) and 5.3 g of the composite catalyst into a 500 mL reaction kettle, heat up to 80 °C, keep the temperature for reaction for 4 h, and keep the normal pressure during the reaction. After the reaction is completed, use a gas chromatograph to analyze the reaction solution, detect whether there are citral self-polymerization products and acetone condensation products, and calculate the citral conversion rate and the selectivity of pseudoionone. The results are shown in Table 4.

[0091] Among them, taking the process of preparing pseudoionone provided in Application Example 8 as an example, the reaction solution after the reaction is filtered and separated, and the obtained catalyst is washed 3 times with deionized water to obtain a recovered catalyst. Then, use the recovered catalyst to carry out the method of preparing pseudoionone provided in Application Example 8 for catalyst reuse. Take the first use of the catalyst as 1 time of reuse, the second use of the catalyst as 2 times of reuse, and so on. Detect whether there are citral self-polymerization products and acetone condensation products, and calculate the citral conversion rate and the selectivity of pseudoionone. The results are shown in Table 5.

[0092] Application Examples 43 - 44

[0093] Application Example 43 - 44 respectively provide an application of a composite catalyst. The composite catalyst uses the composite catalyst provided in Example 8 above and is used for the preparation of pseudo - ionone. The difference between the preparation method and Application Example 8 is only that the molar amounts of acetone are adjusted to 1.5 mol and 1.25 mol in sequence.

[0094] After the reaction is completed, a gas chromatograph is used to analyze the reaction solution to detect whether there are citral self - polymerization products and acetone condensation products, and calculate the citral conversion rate and the selectivity of pseudo - ionone. The results are shown in Table 4.

[0095] Application Examples 45 - 47

[0096] Application Examples 43 - 47 respectively provide an application of a composite catalyst. The composite catalyst uses the composite catalyst provided in Example 8 above and is used for the preparation of pseudo - methyl ionone. The difference between the preparation method and Application Example 8 is only that acetone is replaced by butanone, and the molar amounts of butanone are 1 mol, 0.5 mol and 1.5 mol in sequence.

[0097] After the reaction is completed, a gas chromatograph is used to analyze the reaction solution to detect whether there are citral self - polymerization products and acetone condensation products, and calculate the citral conversion rate and the selectivity of pseudo - methyl ionone. The results are shown in Table 4.

[0098] Application Comparative Examples 1 - 4

[0099] Application Comparative Examples 1 - 4 respectively provide an application of a composite catalyst. The difference from Application Example 8 is only that the composite catalysts used are the composite catalysts provided in Comparative Examples 1 - 4 above in sequence.

[0100] After the reaction is completed, a gas chromatograph is used to analyze the reaction solution to detect whether there are citral self - polymerization products and acetone condensation products, and calculate the citral conversion rate and the selectivity of pseudo - ionone. The results are shown in Table 4.

[0101] Table 4

[0102]

[0103]

[0104]

[0105] Table 5

[0106]

[0107]

[0108] The following points can be seen from the data in Table 4 and Table 5:

[0109] (1) From the data of Application Examples 1-47, it can be seen that under relatively optimal conditions, using the composite catalyst provided by the present invention, taking the synthesis of pseudo-ionone as an example, the conversion rate of citral reaches more than 97.1%, and the selectivity of pseudo-ionone reaches more than 98.1%, and no self-polymerization product of citral and acetone condensation product is produced; taking the synthesis of pseudo-methyl ionone as an example, the conversion rate of citral reaches more than 99.1%, and the selectivity of pseudo-methyl ionone reaches more than 98.8%, and no self-polymerization product of citral and acetone condensation product is produced; the obtained catalyst can be recycled. Taking the composite catalyst provided in Example 8 as an example, after being recycled 10 times, the conversion rate of citral can still reach more than 99.1%, and the selectivity of pseudo-ionone can still reach more than 99.2%.

[0110] (2) By comprehensively comparing the data of Application Example 8 and Application Examples 17-23, it can be seen that by preferably using molecular sieve carriers such as SAPO-34 carrier, ZSM-5 carrier, SAPO-11 carrier, Hβ carrier, Sn-β carrier, SAPO-18 carrier, SAPO-5 carrier, etc., compared with using a zeolite carrier in Application Example 23, the conversion rate of citral and the selectivity of the product can be further improved.

[0111] (3) By comprehensively comparing the data of Application Example 8 and Application Examples 24-28, it can be seen that by preferably controlling the mass ratio of the active metal atom to the carrier, compared with the mass ratio of the active metal atom to the carrier not being within the preferred range in Application Examples 27-28, the conversion rate of citral and the selectivity of the product can be further improved, and the amount of the active metal used can be reduced, and the production cost can be lowered.

[0112] (4) By comprehensively comparing the data of Application Example 8 and Application Examples 29-34, it can be seen that by preferably controlling the mass ratio of the modifier to the active metal atom, compared with the mass ratio of the modifier to the active metal atom not being within the preferred range in Application Examples 33-34, the conversion rate of citral and the selectivity of the product can be further improved, and the generation of by-products can be reduced, the amount of the modifier used can be reduced, and the production cost can be lowered.

[0113] (5) By comprehensively comparing the data of Application Example 8 and Comparative Application Examples 1-2, it can be seen that by using a methoxysilane compound as a modifier and reacting it with an active metal salt and loading it on a carrier with a rich pore structure, the composite catalyst can have high activity and product selectivity.

[0114] (6) By comprehensively comparing the data of Application Example 8 and Comparative Application Examples 3-4, it can be seen that in the preparation method provided by the present invention, on the one hand, it is controlled to first react the methoxysilane compound modifier with the active metal salt, and then use the carrier to adsorb the active ingredient. On the other hand, it is controlled to remove the solvent by rotary evaporation, avoiding the operation of high-temperature calcination, which can make the composite catalyst have high activity and product selectivity.

[0115] In summary, the composite catalyst provided by the present invention is used for the preparation of pseudo-ionone compounds by aldol condensation reaction, and has the advantages of mild reaction conditions, high reaction yield and simple post-treatment, which is beneficial to industrial application.

[0116] The applicant declares that the above description is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived within the technical scope disclosed by the present invention by those skilled in the art all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A composite catalyst, characterized in that: The composite catalyst comprises a carrier and an active component supported on the carrier; The active ingredient includes a complex formed by a modifier and an active metal atom; The modifier includes a methoxysilane compound; The active metal atoms include transition metals; The transition metal includes any one or a combination of at least two of iron, copper, nickel, zirconium or molybdenum; The support comprises a molecular sieve.

2. The composite catalyst according to claim 1, characterized in that The mass ratio of the modifier to the active metal atom is (2.0-10.0):1; The mass ratio of the active metal atoms to the carrier is (0.03-0.09):

1.

3. The composite catalyst according to claim 1, characterized in that The methoxysilane compound includes any one of (3-mercaptopropyl)trimethoxysilane, trimethoxy[3-(phenylamino)propyl]silane, 3-(methacryloyloxy)propyltrimethoxysilane, (3-chloropropyl)trimethoxysilane, trimethoxy[3-(methylamino)propyl]silane, propyltrimethoxysilane, allyltrimethoxysilane, trimethoxy(3,3,3-trifluoropropyl)silane or (3-methoxypropyl)trimethoxysilane, or a combination of at least two thereof.

4. The composite catalyst according to claim 1, characterized in that The molecular sieve includes any one of ZSM-5, Hβ, Sn-β, SAPO-18, SAPO-34, SAPO-11 or SAPO-5, or a combination of at least two thereof.

5. A method for preparing a composite catalyst as claimed in any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: (1) mixing an active metal salt and a modifier in a solvent, and then reacting to obtain a mixed solution; (2) mixing the mixed solution obtained in step (1) with a carrier for adsorption to obtain a catalyst solution; (3) removing the solvent from the catalyst solution obtained in step (2) to obtain a catalyst.

6. The preparation method according to claim 5, characterized in that: The reaction temperature in step (1) is 80-120°C; The reaction time is 2-6h.

7. The preparation method according to claim 5, characterized in that: Stirring during the adsorption process of step (2); The stirring time is 4-8h; The adsorption temperature is 40-80°C.

8. The preparation method according to claim 5, characterized in that: The method for removing the solvent in step (3) includes any one of rotary evaporation, filtration or evaporation to dryness, or a combination of at least two of them.

9. Use of the composite catalyst according to any one of claims 1 to 4, characterized in that: The composite catalyst is used for synthesizing pseudoionone compounds.

10. The use of the composite catalyst according to claim 9, characterized in that: The preparation method of the pseudoionone compound comprises: Citral and ketones are subjected to aldol condensation reaction under the action of a composite catalyst to obtain pseudoionone compounds; The ketones include acetone and / or butanone; The molar ratio of the ketone to citral is (1-3):1; The mass ratio of the composite catalyst to citral is (0.01-0.1):1.

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