A metal complex catalyst, preparation method and application thereof, and preparation method of isopentenal
By using metal complex catalysts to carry out the oxidative isomerization reaction of isopential under low temperature conditions, the problems of easy deactivation and low selectivity of the catalyst are solved, and efficient and stable preparation of isopential is achieved, reducing the process Complexity and energy consumption.
Patent Information
- Application Number
- CN202310264571.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-03-15
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2043-03-15
AI Technical Summary
In the existing isoprenal preparation methods, the catalyst is prone to deactivate, has low selectivity, and needs to be carried out at higher temperatures, resulting in complex processes and high energy consumption.
Using metal complex catalysts, including metal salts and short carbon chain acid ligands, a stable catalyst is obtained through heat treatment and post-treatment, and the oxidative isomerization of isopentenal at lower temperatures, using metal-oxygen bonds and synergistically improve catalytic activity and selectivity.
It has achieved efficient preparation of isopentenal at lower temperatures, with good catalyst stability, high selectivity, mild reaction conditions, significantly improved conversion and selectivity, and low equipment requirements and low cost.
Smart Images
Figure CN116273187B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of organic synthesis, and relates to a metal complex catalyst, a preparation method and application thereof, and a preparation method of isopentenal. Background Art
[0002] Isopentenal, also known as 3-methyl-2-butene-1-aldehyde, has a CAS number of 107-86-8 and a molecular formula of C5H8O. It is mainly used in the preparation of terpene flavors. It is an important raw material for the synthesis of citral and an important chemical intermediate for the preparation of vitamins. Therefore, the research on the process technology for the preparation of isopentenal is of vital importance.
[0003] The Chinese patent with publication number CN111992220 A discloses a method for preparing isopentanal, wherein the catalyst is mainly chromium oxide, supplemented with zinc oxide, copper oxide and zirconium oxide for modification, and the preparation method adopts a coprecipitation method, wherein the above-mentioned metal soluble salts are dissolved in water in a certain proportion, mixed, and then a precipitant is added for coprecipitation, and the precipitate is calcined and compacted by a kneader to form a catalyst, which is simple to produce and convenient to load the catalyst. However, the dehydrogenation process of the invention needs to be carried out under temperature control and at a relatively high temperature, such as 200°C-500°C. Preferably, the dehydrogenation process in the invention can be completed at 280°C to 350°C; and the catalyst is easily deactivated, and the selectivity of isopentanal is low. Summary of the invention
[0004] The purpose of the present invention is to solve the deficiencies of the above-mentioned technology and provide a metal complex catalyst and a preparation method and application thereof, and a method for preparing isopentanal, so that the catalyst can be prepared at a relatively low temperature, the catalytic activity of the catalyst is stable, and the selectivity of isopentanal is relatively high.
[0005] To this end, the present invention provides a metal complex catalyst, which includes a metal salt and a short carbon chain acidic ligand, wherein the short carbon chain acidic ligand bridges the metal ion of the metal salt; the metal salt is one or both of Ag salt and Cu salt; and the short carbon chain acidic ligand is a ligand modified by a sulfonic acid group or a carboxylic acid group.
[0006] The present invention also provides a method for preparing a metal complex catalyst, the steps comprising: mixing and heating a metal salt, a short carbon chain acidic ligand, an organic solvent and deionized water for reaction, wherein the metal salt is one or both of an Ag salt and a Cu salt, and the short carbon chain acidic ligand is a ligand modified by a sulfonic acid group or a carboxylic acid group; after the reaction is completed, solid-liquid separation is performed, and the separated solid is subjected to post-treatment to obtain a metal complex catalyst. The role of the organic solvent and the deionized water is to disperse the components during the preparation of the catalyst, specifically: the organic solvent dissolves and disperses the short carbon chain acidic ligand, and the deionized water disperses and dissolves the metal salt; the organic solvent and the deionized water effectively react the metal salt and the short carbon chain acidic ligand with each other in a liquid environment, promote the formation of the metal complex crystal structure, and are in a stable state.
[0007] Preferably, the metal salt is any one or a combination of two of chloride, nitrate, sulfate or hydrate of Ag or Cu.
[0008] Preferably, the short carbon chain acidic ligand is selected from one or more of isobutyric acid, phthalic acid, trimesic acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 5-sulfoisophthalic acid, 5-sulfo-1,2,4-trimethylbenzenesulfonic acid, and 2,6-dicarboxy-4,8-dinaphthalenesulfonic acid.
[0009] Preferably, the reaction is carried out under a nitrogen environment, and the reaction temperature is controlled at 100-180°C.
[0010] Preferably, after the reaction is completed, the temperature is lowered and then the solid-liquid separation is performed, and the post-treatment method is: the separated solid is washed and dried.
[0011] Preferably, the organic solvent is one of N,N-dimethylformamide (English abbreviation: DMF) and N,N-dimethylacetamide (English abbreviation: DMAC).
[0012] Preferably, when the metal salt is Ag salt and Cu salt, the molar ratio of Ag salt to Cu salt is 1 to 10:1.
[0013] Preferably, the molar ratio of the metal salt, the short carbon chain acidic ligand, the organic solvent, and the deionized water is 1:(0.41-1.5):(15-75):(5-30).
[0014] Preferably, the metal salt, the short carbon chain acidic ligand, the organic solvent and the deionized water are added to a high pressure reactor after stirring or ultrasonication, and the reaction is heated after nitrogen substitution.
[0015] The metal complex catalyst described in any one of the above items is used as a catalyst for preparing isopentenal from 3-methyl-3-butene-1-ol.
[0016] The present invention also provides a method for preparing isopentanal, comprising: in the presence of the metal complex catalyst according to any one of the above items, 3-methyl-3-butene-1-ol and an oxidant undergo an oxidative isomerization reaction, and after the reaction is completed, post-processing is performed to obtain the isopentanal.
[0017] Preferably, the mass ratio of the metal complex catalyst to 3-methyl-3-butene-1-ol is 0.01 to 0.05:1;
[0018] Preferably, the oxidant is selected from air or oxygen; the chemical equation for preparing isopentanal is as follows:
[0019]
[0020] Preferably, the reaction temperature is 80-150° C., and the reaction pressure is 1.0-2.0 MPa.
[0021] Preferably, the post-treatment method is: cooling after the reaction is completed, and then solid-liquid separation is performed to separate the metal complex catalyst to obtain a reaction liquid; the reaction liquid is distilled, the vacuum degree in the distillation tower is maintained at 5 to 10 KPa, the kettle temperature is 140 to 160° C., and the tower top temperature is 50 to 70° C. to obtain isopentanal.
[0022] The reaction mechanism of the above-mentioned preparation of metal complex catalyst: the metal complex catalyst used in the present invention is mainly prepared from metal salt (Ag salt and / or Cu salt) and short carbon chain acidic ligand. The metal ion is modified by using a short carbon chain acidic ligand containing a sulfonic acid group or a carboxylic acid group, and the metal ion is bridged by the short carbon chain acidic ligand to form a metal-organic complex with a stable structure, that is, a metal complex catalyst is obtained. Among them, the carboxylic acid group has a strong coordination ability, while the coordination ability of the sulfonic acid group is slightly weaker, but one sulfonic acid oxygen atom can form three metal-oxygen bonds at the same time, and a large number of metal-oxygen bonds and carboxylic acid groups will produce a very strong synergistic effect. Therefore, the catalyst provided by the present invention has the advantages of large specific surface area, high activity, good stability, and the ability to provide acidic conditions, and shows higher catalytic activity and stability. The metal ion modified by the short carbon chain acidic ligand has a very strong affinity, which is not only easy to combine with the reaction substrate, but also can effectively prevent the material from coking and extend the service life of the catalyst. At the same time, because short carbon chain acidic ligands have greater steric hindrance, they can inhibit the occurrence of side reactions and improve the selectivity of the main reaction.
[0023] The reaction mechanism for preparing isopentenal is as follows: 3-methyl-3-butene-1-ol preferentially undergoes oxidation reaction in the presence of the metal complex catalyst and oxygen to generate 3-methyl-3-butene-1-aldehyde. 3-methyl-3-butene-1-aldehyde is unstable at 80-150° C. and acidic conditions, and double bond isomerization occurs, and the double bond undergoes lateral migration to form a relatively stable α, β unsaturated aldehyde, i.e., isopentenal.
[0024] In addition, in the actual reaction process, the reaction solution will contain a very small amount of by-products, isopentenol and water. After isopentenol is recovered, it can be applied to the above step (2) of this reaction to continue the reaction and finally be oxidized to isopentenal.
[0025] The beneficial effects of the present invention are as follows: the present invention provides a metal complex catalyst, a preparation method thereof, and an application thereof, and a preparation method for isopentanal. The preparation method uses 3-methyl-3-butene-1-ol as a raw material, a metal complex as a catalyst, and oxygen in the air as an oxidant, and does not require the addition of a solvent to obtain isopentanal by reaction.
[0026] (1) The method has a mild reaction system, a simple and easy process, a low reaction temperature, mild reaction conditions, and a high conversion rate and selectivity. The conversion rate of 3-methyl-3-butene-1-ol can reach 99.45%, and the selectivity of isopentenal can reach 97%.
[0027] (2) Metal complex catalysts are stable, not easily deactivated by coking, and still have high activity after repeated use.
[0028] (3) The present invention has low requirements on equipment, the materials are non-corrosive to the equipment, and the equipment investment cost is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0030] Figure 1 is the gas chromatogram of the reaction solution of Example 10;
[0031] Figure 2 This is the gas chromatogram of isopentenal standard. DETAILED DESCRIPTION
[0032] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. The methods used in the present invention are conventional methods unless otherwise specified; the raw materials and devices used are conventional commercial products unless otherwise specified.
[0033] Example 1
[0034] 31.9 g (0.11 mol) of 5-sulfonic-1,2,4-trimethic acid was dissolved in 160.8 g (2.2 mol) of organic solvent DMF, and then 39.6 g (2.2 mol) of deionized water, 17 g (0.1 mol) of AgNO3 and 1.9 g (0.01 mol) of Cu(NO3)2 were added. After ultrasonication for 20 min, the mixture was added into a high-pressure reactor, replaced with nitrogen, heated to 150°C, reacted for 10 h, and then cooled. After the temperature dropped to 10°C, solid-liquid separation was carried out. The separated solid was washed with deionized water until neutral and dried at room temperature for 5 h to obtain the metal complex catalyst CAT-1.
[0035] Among them, the molar ratio of metal salt (AgNO3 and Cu(NO3)2), short carbon chain acidic ligand 5-sulfonic-1,2,4-trimethic acid, organic solvent DMF and deionized water is 0.11:0.11:2.2:2.2, that is, 1:1:20:20.
[0036] Example 2
[0037] 29.5 g (0.12 mol) of 5-sulfonic isophthalic acid was dissolved in 219 g (3.0 mol) of organic solvent DMF, and then 81 g (4.5 mol) of deionized water, 10.7 g (0.075 mol) of AgCl and 18.7 g (0.075 mol) of Cu(SO4)2·5H2O were added. After ultrasonication for 30 min, the mixture was added into a high-pressure reactor, replaced with nitrogen, heated to 180°C, reacted for 3 h, and then cooled. After the temperature dropped to 5°C, solid-liquid separation was performed. The separated solid was washed with deionized water until it was neutral and dried at room temperature for 10 h to obtain the metal complex catalyst CAT-2.
[0038] The molar ratio of the metal salt (AgCl and Cu(SO4)2·5H2O), the short carbon chain acidic ligand 5-sulfoisophthalic acid, the organic solvent DMF and the deionized water is 0.15:0.12:3.0:4.5, i.e. 1:0.8:20:30.
[0039] Example 3
[0040] 21.1 g (0.24 mol) of isobutyric acid was dissolved in 263.1 g (3.6 mol) of organic solvent DMF, and then 21.6 g (1.2 mol) of deionized water, 62.4 g (0.2 mol) of Ag2SO4 and 6.1 g (0.04 mol) of CuCl2·2H2O were added. After ultrasonic treatment for 10 min, the mixture was added into a high-pressure reactor, replaced with nitrogen, heated to 100°C, reacted for 10 h, and then cooled. After the temperature dropped to 20°C, solid-liquid separation was performed. The separated solid was washed with deionized water until it was neutral and dried at room temperature for 5 h to obtain the metal complex catalyst CAT-3.
[0041] The molar ratio of the metal salt (Ag2SO4 and CuCl2·2H2O), the short carbon chain acidic ligand isobutyric acid, the organic solvent and the deionized water is 0.24:0.24:3.6:1.2, that is, 1:1:15:5.
[0042] Example 4
[0043] 13.5 g (0.081 mol) of phthalic acid was dissolved in 348.48 g (4.0 mol) of organic solvent DMAC, and then 18 g (1.0 mol) of deionized water and 17.0 g (0.1 mol) of AgNO3 were added. After stirring and dissolving, the mixture was added into a high-pressure reactor, replaced with nitrogen, heated to 150°C, reacted for 4 hours, and then cooled. After the temperature dropped to 25°C, solid-liquid separation was performed. The separated solid was washed with deionized water until neutral and dried at room temperature for 6 hours to obtain the metal complex catalyst CAT-4.
[0044] The molar ratio of the metal salt AgNO3, the short carbon chain acidic ligand phthalic acid, the organic solvent DMAC and the deionized water is 0.1:0.081:4:1.0, that is, 1:0.81:40:10.
[0045] Example 5
[0046] 47.28 g (0.225 mol) of trimesic acid was dissolved in 261.36 g (3.0 mol) of organic solvent DMAC, and then 54 g (3.0 mol) of deionized water, 17.0 g (0.1 mol) of AgNO3 and 8.0 g (0.05 mol) of Cu(SO4)2 were added. After stirring and dissolving, the mixture was added into a high-pressure reactor, replaced with nitrogen, heated to 160°C, reacted for 6 hours, and cooled. After the temperature dropped to 10°C, solid-liquid separation was performed. The separated solid was washed with deionized water until neutral and dried at room temperature for 4 hours to obtain the metal complex catalyst CAT-5.
[0047] The molar ratio of the metal salt (AgNO3 and Cu(SO4)2), the short carbon chain acidic ligand trimesic acid, the organic solvent DMAC and the deionized water is 0.15:0.225:3:3, that is, 1:1.5:20:20.
[0048] Example 6
[0049] 22.9 g (0.11 mol) of 2-naphthalenesulfonic acid was dissolved in 287.5 g (3.9 mol) of organic solvent DMF, and then 49.5 g (2.75 mol) of deionized water, 17.0 g (0.1 mol) of AgNO3 and 1.6 g (0.01 mol) of Cu(SO4)2 were added. After stirring and dissolving, the mixture was added into a high-pressure reactor, replaced with nitrogen, heated to 120°C, reacted for 8 hours, and cooled. After the temperature dropped to 10°C, solid-liquid separation was carried out. The separated solid was washed with deionized water until neutral and dried at room temperature for 4 hours to obtain the metal complex catalyst CAT-6.
[0050] Among them, the molar ratio of metal salt (AgNO3 and Cu(SO4)2), short carbon chain acidic ligand 2-naphthalenesulfonic acid, organic solvent DMF and deionized water is 0.11:0.11:3.9:2.75, that is, 1:1:35.5:25.
[0051] Example 7
[0052] 15.6 g (0.075 mol) of 1-naphthalenesulfonic acid was dissolved in 435.6 g (5.0 mol) of organic solvent DMAC, and then 54 g (3.0 mol) of deionized water and 17.0 g (0.1 mol) of CuCl2·2H2O were added. After stirring and dissolving, the mixture was added into a high-pressure reactor, replaced with nitrogen, heated to 150°C, reacted for 5 hours, and then cooled. After the temperature dropped to 10°C, solid-liquid separation was performed. The separated solid was washed with deionized water until it was neutral and dried at room temperature for 4 hours to obtain the metal complex catalyst CAT-7.
[0053] The molar ratio of the metal salt CuCl2·2H2O, the short carbon chain acidic ligand 1-naphthalenesulfonic acid, the organic solvent DMAC and the deionized water is 0.1:0.075:5.0:3.0, that is, 1:0.75:50:30.
[0054] Example 8
[0055] 15.6 g (0.041 mol) of 2,6-dicarboxy-4,8-naphthalenesulfonic acid and 13.5 g (0.081 mol) of phthalic acid were dissolved in 653.4 g (7.5 mol) of organic solvent DMAC, and then 54 g (3.0 mol) of deionized water and 17.0 g (0.1 mol) of CuCl2·2H2O were added. After stirring and dissolving, the mixture was added into a high-pressure reactor, replaced with nitrogen, heated to 150°C, reacted for 5 hours, and then cooled. After the temperature dropped to 10°C, solid-liquid separation was performed. The separated solid was washed with deionized water until it was neutral and dried at room temperature for 4 hours to obtain a metal complex catalyst CAT-8.
[0056] The molar ratio of the metal salt CuCl2·2H2O, the short carbon chain acidic ligand 2,6-dicarboxyl-4,8-dinaphthalenesulfonic acid and phthalic acid, the organic solvent DMAC and deionized water is 0.1:0.041:7.5:3.0, that is, 1:0.41:75:30.
[0057] Example 9
[0058] 15.6 g (0.041 mol) of 2,6-dicarboxy-4,8-dinaphthalenesulfonic acid was dissolved in 87.12 g (1.0 mol) of organic solvent DMAC, and then 54 g (3.0 mol) of deionized water and 17.0 g (0.1 mol) of CuCl2·2H2O were added. After stirring and dissolving, the mixture was added into a high-pressure reactor, replaced with nitrogen, heated to 160°C, reacted for 4 hours, and then cooled. After the temperature dropped to 10°C, solid-liquid separation was performed. The separated solid was washed with deionized water until it was neutral and dried at room temperature for 4 hours to obtain a metal complex catalyst CAT-9.
[0059] The molar ratio of the metal salt CuCl2·2H2O, the short carbon chain acidic ligand 2,6-dicarboxyl-4,8-dinaphthalenesulfonic acid, the organic solvent DMAC and the deionized water is 0.1:0.041:1.0:3.0, that is, 1:0.41:10:30.
[0060] Example 10
[0061] 600g 3-methyl-3-butene-1-ol and 12g catalyst CAT-1 prepared in Example 1 were added to a 1L reactor, i.e., the amount of catalyst CAT-1 was 2% of the amount of 3-methyl-3-butene-1-ol. Nitrogen was replaced three times, stirring was started, and after heating to 150°C, air was started to increase the pressure in the reactor to 1.5MPa to start the reaction. After the pressure in the reactor dropped, air was passed to keep the pressure in the reactor at 1.5MPa. After a certain reaction time, the pressure in the reactor no longer dropped, and the reaction was terminated; the reaction time was 3h. After the reaction was completed, the temperature was lowered, and then solid-liquid separation was performed to separate the metal complex catalyst to obtain a reaction solution; finally, the reaction solution was distilled to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol was 99.45%, and the selectivity of isopentanal was 97.0%.
[0062] The reaction liquid obtained after solid-liquid separation in Example 10 was subjected to gas chromatography detection. The test conditions were: Fuli gas chromatograph, model 9790plus; chromatographic column: SE-30, model 30m×0.25mm×0.25μm; column box temperature 120°C, vaporization chamber temperature 250°C, and detection chamber temperature 250°C. The gas chromatogram of the reaction liquid in the final Example 10 is shown in the attached Figure 1 , with attached Figure 2 By comparing the gas chromatogram of the isopentanal standard, it was determined that in Example 10, the reaction solution was finally distilled to obtain the product isopentanal.
[0063] Embodiment 11
[0064] 600g 3-methyl-3-butene-1-ol and 6g catalyst CAT-2 prepared in Example 2 were added to a 1L reactor, i.e., the amount of catalyst CAT-2 was 1.0% of the amount of 3-methyl-3-butene-1-ol. Nitrogen was replaced three times, stirring was started, and after heating to 150°C, air was started to increase the pressure in the reactor to 1.2MPa to start the reaction. After the pressure in the reactor dropped, air was passed to keep the pressure in the reactor at 1.2MPa. After a certain reaction time, the pressure in the reactor no longer dropped, and the reaction ended; the reaction time was 6h. After the reaction ended, the temperature was lowered, and then the solid-liquid separation was performed to separate the metal complex catalyst to obtain a reaction solution; finally, the reaction solution was distilled to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol was 95%, and the selectivity of isopentanal was 95.5%.
[0065] Example 12
[0066] 600g 3-methyl-3-butene-1-ol and 18g catalyst CAT-3 prepared in Example 3 were added to a 1L reactor, i.e., the amount of catalyst CAT-3 was 3.0% of the amount of 3-methyl-3-butene-1-ol. Nitrogen was replaced three times, stirring was started, and after heating to 80°C, air was started to increase the pressure in the reactor to 2.0MPa to start the reaction. After the pressure in the reactor dropped, air was passed to keep the pressure in the reactor at 2.0MPa. After a certain reaction time, the pressure in the reactor no longer dropped, and the reaction ended; the reaction time was 2h. After the reaction ended, the temperature was lowered, and then solid-liquid separation was performed to separate the metal complex catalyst to obtain a reaction solution; finally, the reaction solution was distilled to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol was 90%, and the selectivity of isopentanal was 96.0%.
[0067] Example 13
[0068] 600g of 3-methyl-3-butene-1-ol and 30g of the catalyst CAT-4 prepared in Example 4 were added to a 1L reactor, i.e., the amount of the catalyst CAT-4 was 5.0% of the amount of 3-methyl-3-butene-1-ol. Nitrogen was replaced three times, stirring was started, and after heating to 100°C, air was started to increase the pressure in the reactor to 1.5MPa to start the reaction. After the pressure in the reactor dropped, air was passed to keep the pressure in the reactor at 1.5MPa. After a certain reaction time, the pressure in the reactor no longer dropped, and the reaction ended; the reaction time was 4h. After the reaction ended, the temperature was lowered, and then the solid-liquid separation was performed to separate the metal complex catalyst to obtain a reaction solution; finally, the reaction solution was distilled to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol was 92%, and the selectivity of isopentanal was 92.5%.
[0069] Embodiment 14
[0070] 600g of 3-methyl-3-butene-1-ol and 21g of the catalyst CAT-5 prepared in Example 5 were added to a 1L reactor, i.e., the amount of catalyst CAT-5 was 3.5% of the amount of 3-methyl-3-butene-1-ol. Nitrogen was replaced three times, stirring was turned on, and after heating to 125°C, air was started to increase the pressure in the reactor to 1.2MPa to start the reaction. After the pressure in the reactor dropped, air was passed to keep the pressure in the reactor at 1.2MPa. After a certain reaction time, the pressure in the reactor no longer dropped, and the reaction ended; the reaction time was 3h. After the reaction ended, the temperature was lowered, and then the solid-liquid separation was performed to separate the metal complex catalyst to obtain a reaction solution; finally, the reaction solution was distilled to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol was 95%, and the selectivity of isopentanal was 94.0%.
[0071] Embodiment 15
[0072] 600g of 3-methyl-3-butene-1-ol and 21g of the catalyst CAT-6 prepared in Example 6 were added to a 1L reactor, i.e., the amount of catalyst CAT-6 was 3.5% of the amount of 3-methyl-3-butene-1-ol. Nitrogen was replaced three times, stirring was started, and after heating to 130°C, air was started to increase the pressure in the reactor to 1.0MPa to start the reaction. After the pressure in the reactor dropped, air was passed to keep the pressure in the reactor at 1.0MPa. After a certain reaction time, the pressure in the reactor no longer dropped, and the reaction ended; the reaction time was 6h. After the reaction ended, the temperature was lowered, and then the solid-liquid separation was performed to separate the metal complex catalyst to obtain a reaction solution; finally, the reaction solution was distilled to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol was 92%, and the selectivity of isopentanal was 95.5%.
[0073] Example 16
[0074] 600g 3-methyl-3-butene-1-ol and 15g catalyst CAT-7 prepared in Example 7 were added to a 1L reactor, i.e., the amount of catalyst CAT-7 was 2.5% of the amount of 3-methyl-3-butene-1-ol. Nitrogen was replaced three times, stirring was started, and after heating to 120°C, air was started to increase the pressure in the reactor to 1.5MPa to start the reaction. After the pressure in the reactor dropped, air was passed to keep the pressure in the reactor at 1.5MPa. After a certain reaction time, the pressure in the reactor no longer dropped, and the reaction ended; the reaction time was 4h. After the reaction ended, the temperature was lowered, and then the solid-liquid separation was performed to separate the metal complex catalyst to obtain a reaction solution; finally, the reaction solution was distilled to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol was 94%, and the selectivity of isopentanal was 95.2%.
[0075] Embodiment 17
[0076] 600g 3-methyl-3-butene-1-ol and 15g catalyst CAT-8 prepared in Example 8 were added to a 1L reactor, i.e., the amount of catalyst CAT-8 was 2.5% of the amount of 3-methyl-3-butene-1-ol. Nitrogen was replaced three times, stirring was started, and after heating to 120°C, air was started to increase the pressure in the reactor to 1.5MPa to start the reaction. After the pressure in the reactor dropped, air was passed to keep the pressure in the reactor at 1.5MPa. After a certain reaction time, the pressure in the reactor no longer dropped, and the reaction ended; the reaction time was 4h. After the reaction ended, the temperature was lowered, and then the solid-liquid separation was performed to separate the metal complex catalyst to obtain a reaction solution; finally, the reaction solution was distilled to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol was 92%, and the selectivity of isopentanal was 96.5%.
[0077] Embodiment 18
[0078] 600g 3-methyl-3-butene-1-ol and 15g catalyst CAT-9 prepared in Example 9 were added to a 1L reactor, i.e., the amount of catalyst CAT-9 was 2.5% of the amount of 3-methyl-3-butene-1-ol. Nitrogen was replaced three times, stirring was started, and after heating to 120°C, air was started to increase the pressure in the reactor to 1.5MPa to start the reaction. After the pressure in the reactor dropped, air was passed to keep the pressure in the reactor at 2.0MPa. After a certain reaction time, the pressure in the reactor no longer dropped, and the reaction ended; the reaction time was 4h. After the reaction ended, the temperature was lowered, and then the solid-liquid separation was performed to separate the metal complex catalyst to obtain a reaction solution; finally, the reaction solution was distilled to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol was 98%, and the selectivity of isopentanal was 95.6%.
[0079] In order to more intuitively compare the catalyst types, catalyst dosages, reaction temperatures, reaction times, reaction pressures, and 3-methyl-3-butene-1-ol conversion rates and isopentenal selectivities of Examples 10 to 18, the following Table 1 is formed.
[0080] Table 1 Summary of relevant data of Examples 10 to 18
[0081]
[0082] Embodiment 19
[0083] Catalyst CAT-1 was subjected to an application test to examine the stability and catalytic activity of the catalyst. Catalyst CAT-1 was obtained by filtering the reaction solution of Example 10 and subjected to an application test. The specific operation was the same as that in Example 10. The experimental data of the application of catalyst CAT-1, including the conversion rate of 3-methyl-3-butene-1-ol and the selectivity of isopentenal, are shown in Table 2 below.
[0084] Table 2 Summary of experimental data for catalyst CAT-1
[0085]
[0086] As shown in Table 2, the catalyst CAT-1 obtained after filtering the reaction liquid of Example 10 was used 9 times. From the data of 3-methyl-3-butene-1-ol conversion rate and isopentanal selectivity, together with Example 10, the catalyst had good conversion rate and selectivity after 10 reactions. It can be seen that the catalyst CAT-1 has high stability and catalytic activity.
[0087] The catalysts CAT-2 to CAT-7 are prepared by the same mechanism as CAT-1. The reaction mechanism is as described above and will not be repeated here. Therefore, CAT-2 to CAT-7 also have high stability and catalytic activity.
[0088] Comparative Example 1
[0089] Commercially available metal Ag catalyst is used to carry out the isomerization oxidation reaction of 3-methyl-3-butene-1-ol to prepare isopentenal.
[0090] 600g 3-methyl-3-butene-1-ol and 3g catalyst Ag were added to a 1L reactor, i.e., the amount of catalyst Ag was 0.5% of the amount of 3-methyl-3-butene-1-ol. Nitrogen was replaced three times, stirring was started, and after heating to 150°C, air was started to increase the pressure in the reactor to 1.5MPa to start the reaction. After the pressure in the reactor dropped, air was passed to keep the pressure in the reactor at 1.5MPa. After a certain reaction time, the pressure in the reactor no longer dropped, and the reaction was terminated. After the reaction was completed, the temperature was lowered, and then solid-liquid separation was performed to separate the catalyst Ag to obtain a reaction solution; finally, the reaction solution was distilled to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol was 80%, the selectivity of isopentanal was 33%, and the selectivity of 3-methyl-3-butene-1-aldehyde was 65%.
[0091] Comparative Example 2: Reaction using organic ligand
[0092] Add 600g 3-methyl-3-butene-1-ol and 6g 5-sulfonic acid-1,2,4-benzenetricarboxylic acid to a 1L reactor, that is, the amount of 5-sulfonic acid-1,2,4-benzenetricarboxylic acid is 1% of the amount of 3-methyl-3-butene-1-ol. Replace with nitrogen three times, start stirring, heat to 150°C, start passing air, raise the pressure in the reactor to 1.5MPa to start the reaction, pass air after the pressure in the reactor drops, and keep the pressure in the reactor at 1.5MPa. After a certain period of reaction, the pressure in the reactor no longer drops, and the reaction is over. After the reaction is over, cool down to obtain a reaction solution; finally, distill the reaction solution to obtain isopentanal. The conversion rate of 3-methyl-3-butene-1-ol is 30%, and the selectivity of isopentanal is 20%.
[0093] It can be seen that compared with Comparative Example 1 and Comparative Example 2, the conversion rate of 3-methyl-3-butene-1-ol and the selectivity of isopentanal in Examples 1 to 15 of the present invention are significantly improved, wherein the conversion rate of 3-methyl-3-butene-1-ol can reach 95%, and the selectivity of isopentanal can reach 99%.
[0094] The invention provides a metal complex catalyst, a preparation method and application thereof, and a preparation method of isopentanal. The preparation method uses 3-methyl-3-butene-1-ol as a raw material, a metal complex as a catalyst, oxygen in the air as an oxidant, and no solvent needs to be added to obtain isopentanal through reaction.
[0095] (1) The method has a mild reaction system, a simple and easy process, a low reaction temperature (80 to 150° C.), mild reaction conditions, and a high conversion rate and selectivity. The conversion rate of 3-methyl-3-butene-1-ol can reach 95%, and the selectivity of isopentenal can reach 99%;
[0096] (2) Metal complex catalysts are stable, not prone to coking and deactivation, and still have high activity after repeated use;
[0097] (3) The present invention has low requirements on equipment, the materials are non-corrosive to the equipment, and the equipment investment cost is low.
[0098] It should be noted that:
[0099] (1) In Examples 1 to 9, the temperature is lowered after a period of reaction. In the actual production process, the reaction time can be adjusted according to the actual situation, usually based on the end of the reaction; circulating water or low-temperature water is used for cooling.
[0100] (3) In Examples 10 to 18, the reaction solution was distilled, and the vacuum degree in the distillation tower was maintained at 5 to 10 KPa, the kettle temperature was 140 to 160° C., and the tower top temperature was 50 to 70° C.
[0101] (4) In Examples 1 to 9, the material dissolution can be carried out by stirring or ultrasound. When the material has poor solubility, ultrasound is preferred. The ultrasound time is usually 10 to 30 minutes.
[0102] (5) Example 10 to Example 19, Comparative Example 1 After the reaction is completed, the temperature is lowered, and then the solid-liquid separation and drying are conventional operations in the art. Usually, the temperature is lowered to 30-50° C. after the reaction is completed.
[0103] (6) In the preparation process of the metal complex catalyst of the present invention, the organic solvent is used to dissolve and disperse the short carbon chain acidic ligand, and the deionized water is used to disperse and dissolve the metal salt; wherein, the organic solvent and the deionized water may be immiscible or miscible; when the two are immiscible, the metal salt and the short carbon chain acidic ligand react in two phases, for example, dichloroethane, dichloromethane, toluene, etc. are organic solvents that are immiscible with water; when the two are miscible, the metal salt and the organic ligand can be effectively mixed together, promoting the full contact and mutual reaction of the metal salt and the short carbon chain acidic ligand. Obviously, it is preferred that the organic solvent and the deionized water are miscible, for example, N, N-dimethylformamide (English abbreviation: DMF) and N, N-dimethylacetamide (English abbreviation: DMAC) used in the preparation of the metal complex catalyst in Examples 1 to 9 of the present invention are organic solvents that are miscible with water.
[0104] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.
Claims
1. A metal complex catalyst is used as a catalyst for preparing isopentenal from 3-methyl-3-butene-1-ol, characterized in that: The metal complex catalyst comprises a metal salt and a short carbon chain acidic ligand, wherein the short carbon chain acidic ligand bridges the metal ion of the metal salt; the metal salt is one or both of Ag salt and Cu salt; the short carbon chain acidic ligand is a ligand modified with a sulfonic acid group or a carboxylic acid group; The short carbon chain acidic ligand is selected from one or more of isobutyric acid, phthalic acid, trimesic acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 5-sulfonic isophthalic acid, 5-sulfonic-1,2,4-trimethylbenzenesulfonic acid, and 2,6-dicarboxy-4,8-dinaphthalenesulfonic acid.
2. The use according to claim 1, characterized in that: The preparation method of the metal complex catalyst comprises: mixing the metal salt, the short carbon chain acidic ligand, the organic solvent and the deionized water for heating and reacting, separating the solid and the liquid after the reaction, and post-treating the separated solid to obtain the metal complex catalyst.
3. The use according to claim 2, characterized in that: The metal salt is any one or a combination of two of chloride, nitrate, sulfate or hydrate of Ag or Cu.
4. The use according to claim 2, characterized in that: The organic solvent is one of N,N-dimethylformamide and N,N-dimethylacetamide.
5. The use according to claim 2, characterized in that: When the metal salt is Ag salt and Cu salt, the molar ratio of Ag salt to Cu salt is 1-10:
1.
6. The use according to claim 2, characterized in that: The molar ratio of the metal salt, the short carbon chain acidic ligand, the organic solvent and the deionized water is 1: (0.41-1.5): (15-75): (5-30).
7. A method for preparing isopentenal, characterized in that: include: In the presence of the metal complex catalyst in the application according to any one of claims 1 to 6, 3-methyl-3-butene-1-ol and an oxidant undergo an oxidative isomerization reaction, and after the reaction is completed, the isopentenal is obtained through post-treatment.
8. The method for preparing isopentenal according to claim 7, wherein The mass ratio of the metal complex catalyst to 3-methyl-3-butene-1-ol is 0.01-0.05:1; the oxidant is selected from air or oxygen; the reaction temperature is 80-150° C., and the reaction pressure is 1.0-2.0 MPa.