Bi-metal center Cr-Co catalyst and preparation method and application thereof

Abstract

The invention relates to the technical field of hydroformylation reaction, and discloses a bimetallic center Cr-Co catalyst and a preparation method and application thereof.The bimetallic center Cr-Co catalyst has the structure shown in the formula (1), R1 and R2 are independently selected from C1-C10 alkyl, C6-C15 aryl and-O-R ', and R' is selected from C1-C10 alkyl, C6-C15 aryl and C7-C15 alkaryl. The catalyst has high conversion rate and high aldehyde selectivity when being used for hydroformylation reaction, and especially can improve the selectivity of straight-chain products in aldehyde. # imgabs0 #

Description

Technical Field

[0001] The invention relates to the technical field of hydroformylation reaction, and in particular to a bimetallic center Cr-Co catalyst and a preparation method and application thereof. Background Art

[0002] Vinyl acetate undergoes hydroformylation reaction with synthesis gas (mixed gas of carbon monoxide and hydrogen) under the action of olefin hydroformylation catalyst to generate 3-acetoxypropionaldehyde and 2-acetoxypropionaldehyde. The products 3-acetoxypropionaldehyde and 2-acetoxypropionaldehyde react with hydrogen under the action of aldehyde hydrogenation catalyst to generate 3-acetoxypropanol and 2-acetoxypropanol, which are hydrolyzed under the action of ester hydrolysis catalyst to generate 1,3-propylene glycol and 1,2-propylene glycol. Or the products 3-acetoxypropionaldehyde and 2-acetoxypropionaldehyde are generated under the action of oxidant to generate important industrial products such as lactic acid and 3-hydroxypropionic acid. These products are all important chemical raw materials, especially 1,3-propylene glycol is an important polyester fiber monomer with high market value. In the past few decades, scientists have been committed to improving the reaction rate and increasing the yield of 3-acetoxypropionaldehyde on the basis of minimizing undesirable by-products.

[0003] The hydroformylation of vinyl acetate shows some special phenomena due to its special structure, which is different from long-chain olefins. The regioselectivity of its products, especially the selectivity of 3-acetoxypropionaldehyde, is difficult to improve, which has always been a problem that troubles scientists. The results of decades of research on the hydroformylation of vinyl acetate show that metal rhodium has a high selectivity for branched products, but a low selectivity for linear products. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem of low selectivity of the existing hydroformylation catalyst for linear products in the prior art, and to provide a bimetallic center Cr-Co catalyst and a preparation method and application thereof.

[0005] In order to achieve the above object, the first aspect of the present invention provides a bimetallic center Cr-Co catalyst having a structure shown in formula (1):

[0006]

[0007] Wherein, R1 and R2 are each independently selected from C1-C 10 Alkyl, C6-C 15 aryl, -O-R', wherein R' is selected from C1-C 10 Alkyl, C6-C 15 Aryl, C7-C 15 of alkylaryl.

[0008] The second aspect of the present invention provides a method for preparing a bimetallic center Cr-Co catalyst, the method comprising: contacting CoCl(CO)(PR1R2H)2 with Cr(CO)6 to carry out a complex reaction, followed by extraction and crystallization;

[0009] Wherein, R1 and R2 are each independently selected from C1-C 10 Alkyl, C6-C 15 aryl, -O-R', wherein R' is selected from C1-C 10 Alkyl, C6-C 15 Aryl, C7-C 15 of alkylaryl.

[0010] The third aspect of the present invention provides a catalyst prepared by the method described above.

[0011] The fourth aspect of the present invention provides use of the above-mentioned catalyst in a hydroformylation reaction.

[0012] A fifth aspect of the present invention provides a method for hydroformylating olefins, the method comprising: contacting the olefin with the above-mentioned catalyst under hydroformylation reaction conditions to react;

[0013] Alternatively, the catalyst is prepared according to the above method, and then the olefin is contacted with the prepared catalyst under hydroformylation reaction conditions to react.

[0014] Through the above technical solution, the present invention achieves the following beneficial effects:

[0015] (1) The present invention provides a bimetallic Cr-Co catalyst, which has a high conversion rate and a high aldehyde selectivity when used in a hydroformylation reaction, and in particular can improve the selectivity of straight-chain products (such as 3-acetoxypropionaldehyde) in aldehydes.

[0016] (2) The bimetallic center Cr-Co catalyst provided by the present invention is a solid catalyst that can be recycled and reused, and the performance of the recycled catalyst is almost equivalent to that of the freshly prepared catalyst, which is beneficial to environmental protection and reduces industrial costs. The catalyst can be recycled 10 times while ensuring the raw material conversion rate and aldehyde selectivity.

[0017] (3) The preparation method of the bimetallic center Cr-Co catalyst provided by the present invention can obtain a higher catalyst yield, reduce the synthesis cost of the catalyst, and is conducive to the industrial large-scale use of the catalyst.

[0018] (4) The catalyst provided by the present invention can cause hydroformylation reaction at a lower temperature, thereby reducing production energy consumption. DETAILED DESCRIPTION

[0019] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0020] The first aspect of the present invention provides a bimetallic Cr-Co catalyst having a structure shown in formula (1):

[0021]

[0022] Wherein, R1 and R2 are each independently selected from C1-C 10 Alkyl, C6-C 15 aryl, -O-R', wherein R' is selected from C1-C 10 Alkyl, C6-C 15 Aryl, C7-C 15 of alkylaryl.

[0023] In the present invention, C1-C 10 The alkyl group may be a straight-chain alkyl group or a branched alkyl group, for example, it may be methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, hexyl, isohexyl, heptyl, isoheptyl, octyl, isooctyl, 2-ethylhexyl, etc.

[0024] In the present invention, C6-C 15 The aryl group may be phenyl, biphenyl, naphthyl or the like.

[0025] According to the present invention, preferably, R1 and R2 are each independently selected from C1-C5 alkyl, C6-C 10 The aryl group is more preferably a methyl group, an ethyl group, a propyl group (eg, n-propyl group, isopropyl group), a butyl group (eg, n-butyl group, isobutyl group), or a phenyl group.

[0026] In the present invention, C7-C 15 The alkylaryl group may be methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, sec-butylphenyl, isobutylphenyl, tert-butylphenyl, n-pentylphenyl, isopentylphenyl, tert-pentylphenyl, neopentylphenyl, hexylphenyl, isohexylphenyl, heptylphenyl, isoheptylphenyl, octylphenyl, isooctylphenyl, 2-ethylhexylphenyl, etc. The oxygen atom in -O-R' may be C7-C 15 The alkyl group in the alkylaryl group can also be connected to the C7-C 15The aryl group of the alkylaryl is connected to the aryl group, preferably, the oxygen atom in -O-R' is connected to the C7-C 15 The alkyl groups in the alkylaryl groups are connected, that is, -O-R' is -O-alkylene-aryl, for example, -OCH2Ph.

[0027] According to the present invention, preferably, R' is selected from C1-C5 alkyl, C6-C 10 Aryl, C7-C 10 more preferably methyl, ethyl, propyl (eg, n-propyl, isopropyl), butyl (eg, n-butyl, isobutyl), phenyl, (methylene) phenyl.

[0028] In the present invention, phenyl group may be abbreviated as Ph.

[0029] The second aspect of the present invention provides a method for preparing a bimetallic center Cr-Co catalyst, the method comprising: contacting CoCl(CO)(PR1R2H)2 with Cr(CO)6 to carry out a complex reaction, followed by extraction and crystallization;

[0030] Wherein, R1 and R2 are each independently selected from C1-C 10 Alkyl, C6-C 15 aryl, -O-R', wherein R' is selected from C1-C 10 Alkyl, C6-C 15 Aryl, C7-C 15 of alkylaryl.

[0031] According to the present invention, in order to further improve the yield of the catalyst, improve the conversion rate and selectivity, preferably, the molar ratio of CoCl(CO)(PR1R2H)2 to Cr(CO)6 is 0.1-3:1 (for example, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 2:1, 2.5:1, 3:1, and the range composed of any two of the above points), more preferably 0.5-1.8:1.

[0032] According to the present invention, the conditions of the complexation reaction are not particularly limited, and can be the complexation reaction conditions commonly used in the art. Preferably, the conditions of the complexation reaction include: a temperature of 15-40° C. and a time of 0.5-5 h.

[0033] According to the present invention, preferably, the complex reaction is carried out in the presence of a solvent, and the solvent used in the complex reaction is a polar solvent, preferably C2-C 10The polar organic solvent is preferably a C2-C6 polar organic solvent containing a heteroatom, wherein the heteroatom is at least one of N, O, and S; and further preferably at least one of tetrahydrofuran, dioxane, N,N-dimethylformamide, dimethyl sulfoxide, diethyl ether, and ethyl acetate.

[0034] According to the present invention, in the present invention, CoCl(CO)(PR1R2H)2 and Cr(CO)6 can be directly added to a solvent for complex reaction, or CoCl(CO)(PR1R2H)2 and Cr(CO)6 can be mixed with a solvent to prepare a solution and then mixed. Preferably, the process of the complex reaction includes: mixing a solution containing CoCl(CO)(PR1R2H)2 with a solution containing Cr(CO)6 for complex reaction.

[0035] According to the present invention, preferably, the process of the complex reaction comprises: dropping a solution containing CoCl(CO)(PR1R2H)2 into a solution containing Cr(CO)6 to carry out a complex reaction.

[0036] According to the present invention, preferably, the dripping rate of the solution containing CoCl(CO)(PR1R2H)2 is 0.1-1 g / min based on the weight of CoCl(CO)(PPh2H)2 per gram of Cr(CO)6. Controlling the dripping rate within the above range can facilitate the complexation reaction.

[0037] According to the present invention, in order to shorten the synthesis time of the catalyst and ensure the yield of the catalyst, preferably, the concentration of the solution containing CoCl(CO)(PR1R2H)2 and the solution containing Cr(CO)6 are independently 0.001-0.1 mol / L, preferably 0.002-0.05 mol / L.

[0038] According to the present invention, preferably, the extraction agent used in the extraction is C6-C 15 Aromatics, C1-C 10 Halogenated alkanes and C1-C 10 At least one of ethers, preferably at least one of toluene, benzene, xylene, dichloromethane, chloroform, ethylene glycol diethyl ether and diethyl ether. In the present invention, unless otherwise specified, the halogen atom or halogen can be selected from F, Cl, Br, and I.

[0039] According to the present invention, preferably, the extraction method is: removing the solvent in the complex reaction liquid to obtain a complex product, then using an extractant to extract the complex product (usually a black-purple oily substance) to obtain an extract, then filtering the extract to obtain a filtrate, and then concentrating the filtrate to obtain a concentrate.

[0040] According to the present invention, preferably, the total amount of the extractant used is 10-100 mL per gram of the oil.

[0041] In the present invention, the solvent in the complex reaction liquid can be removed by vacuum distillation. The conditions of the vacuum distillation can be determined according to the type of solvent, as long as the weight of the complex product can be guaranteed not to change. For example, when tetrahydrofuran is used as the solvent, the conditions of the vacuum distillation can be 0.03-0.05MPa; for another example, when dioxane is used as the solvent, the conditions of the vacuum distillation can be 0.01-0.04MPa.

[0042] In the present invention, it is understood that the extraction is to use an extractant to dissolve the active ingredient (catalyst) in the complex product, and then remove the solid (unreacted raw material or reaction by-product) by filtering. The extractant can be divided into several parts to extract the complex product in batches. Usually, the extractant is divided into 3-6 parts according to the total amount for extraction.

[0043] In the present invention, the filtrate can be concentrated by vacuum distillation, and the conditions of the vacuum distillation can be determined according to the type of solvent.

[0044] According to the present invention, preferably, the crystallization temperature is -60°C to -10°C (for example, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, and a range consisting of any two of the above). The crystallization time is not particularly limited, and usually, it can be 5-20 hours.

[0045] According to the present invention, the crystallization method may be a crystallization method commonly used in the art, for example, the concentrated solution obtained by extraction is contacted with a crystallization solvent for crystallization.

[0046] According to the present invention, preferably, the crystallization solvent is selected from at least one of diethyl ether, petroleum ether, cyclohexane, n-hexane and ethyl acetate.

[0047] According to the present invention, preferably, the crystallization solvent comprises a crystallization solvent A and a crystallization solvent B, wherein the crystallization solvent A is selected from ether and / or ethyl acetate; and the crystallization solvent B is selected from at least one of cyclohexane, normal hexane and petroleum ether. The crystallization solvent may be at least one of a combination of ether / petroleum ether, a combination of ether / cyclohexane, a combination of ether / normal hexane, a combination of ethyl acetate / petroleum ether, a combination of ethyl acetate / cyclohexane, and a combination of ethyl acetate / normal hexane. More preferably, the volume ratio of the crystallization solvent A to the crystallization solvent B is 0.01-10:1 (e.g., 0.01:1, 0.1:1, 0.5:1, 1:1, 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, and a range consisting of any two of the above), and further preferably 1-1.5:1.

[0048] According to the present invention, preferably, the crystallization solvent is diethyl ether and petroleum ether, and further preferably, the volume ratio of diethyl ether to petroleum ether is 0.01-10:1, and more preferably 1-1.5:1.

[0049] According to the present invention, preferably, the amount of the crystallization solvent used is 10-80 mL, more preferably 15-50 mL, relative to 1 mL of the concentrate.

[0050] The third aspect of the present invention provides a catalyst prepared by the method described above.

[0051] The fourth aspect of the present invention provides use of the above-mentioned catalyst in a hydroformylation reaction.

[0052] A fifth aspect of the present invention provides a method for hydroformylating olefins, the method comprising: contacting the olefin with the above-mentioned catalyst under hydroformylation reaction conditions to react;

[0053] Alternatively, the catalyst is prepared according to the above method, and then the olefin is contacted with the prepared catalyst under hydroformylation reaction conditions to react.

[0054] According to the present invention, preferably, the weight ratio of the catalyst to the olefin is 0.0001-1:1 (for example, 0.0001:1, 0.001:1, 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, 0.1:1, 0.5:1, 1:1, and the range formed by any two of the above points), more preferably 0.01-0.1:1.

[0055] According to the present invention, preferably, the olefin is an ester-substituted olefin; more preferably, it is an ester-substituted olefin having a total carbon atom number of 4-20; further preferably, it is an acetate-substituted olefin having a total carbon atom number of 4-20; and further preferably, it is at least one of vinyl acetate, vinyl propionate, vinyl butyrate and vinyl isobutyrate.

[0056] According to the present invention, preferably, the hydroformylation reaction conditions include: temperature of 50-200° C., and time of 0.1-2 h.

[0057] According to the present invention, preferably, the raw material for the hydroformylation reaction also includes synthesis gas, which is a mixture of carbon monoxide and hydrogen; more preferably, the volume ratio of carbon monoxide to hydrogen in the mixture is 0.1-10:1, more preferably 0.1-7:1.

[0058] According to the present invention, preferably, the pressure of the synthesis gas in the hydroformylation reaction is controlled to be 1-8 MPa, more preferably 4-7 MPa.

[0059] In the present invention, the hydroformylation reaction can be carried out in the presence of a solvent, and the solvent can be n-hexane, cyclohexane, toluene, xylene, dioxane, chlorobenzene, 1,2-dichloroethane and the like. The weight ratio of the solvent to the olefin can be 0.1-100:1, or 5-10:1. The amount of the solvent used is 5-10 mL per gram of the olefin.

[0060] The present invention will be described in detail below by way of examples. In the following examples and test examples,

[0061] The room temperature is about 25°C;

[0062] The volume ratio of CO:H2 in the synthesis gas is 2:1.

[0063] The yield of catalyst mol% = the amount of substance of catalyst ÷ the amount of substance of CoCl(CO)(PPh2H)2 × 100%;

[0064] Vinyl acetate conversion rate mol% = (the amount of vinyl acetate added - the amount of residual vinyl acetate in the product) ÷ the amount of vinyl acetate added × 100%;

[0065] Aldehyde selectivity mol% = (the amount of 3-acetoxypropionaldehyde substance + the amount of 2-acetoxypropionaldehyde substance) / (the amount of olefin substance added to the reaction system - the amount of olefin substance remaining in the system) × 100%

[0066] Selectivity of 3-acetoxypropionaldehyde, mol %=amount of 3-acetoxypropionaldehyde substance÷(amount of 3-acetoxypropionaldehyde substance+amount of 2-acetoxypropionaldehyde substance)×100%.

[0067] Example 1

[0068] (1) Under nitrogen protection, 560 mg of CoCl(CO)(PPh2H)2 was mixed with 100 mL of tetrahydrofuran to obtain a tetrahydrofuran solution of CoCl(CO)(PPh2H)2 (blue-purple); 485 mg of Cr(CO)6 was mixed with 100 mL of tetrahydrofuran to obtain a tetrahydrofuran solution of Cr(CO)6. The tetrahydrofuran solution of CoCl(CO)(PPh2H)2 was added dropwise to the tetrahydrofuran solution of Cr(CO)6, and the reaction was stirred at room temperature for 3 h to obtain a complex reaction solution (black-purple). The dropping rate of the tetrahydrofuran solution of CoCl(CO)(PPh2H)2 was 0.1 g / min based on the weight of CoCl(CO)(PPh2H)2 per gram of Cr(CO)6.

[0069] (2) The complex reaction solution is then subjected to vacuum distillation to remove tetrahydrofuran, and the vacuum distillation is stopped after the weight of the residue no longer changes, to obtain a dark purple oily substance. The oily substance is washed with toluene for several times, and after the color of the toluene no longer changes, the washings are combined as an extract. The extract is filtered through diatomaceous earth to obtain a filtrate, and the filtrate is concentrated to obtain a concentrated solution (5 mL). The total amount of toluene used is 60 mL per gram of the oily substance.

[0070] (3) Add ether and petroleum ether to the flask containing the concentrated solution, then let the flask stand at -30°C overnight (about 12 hours) to precipitate yellow-green crystals, which were filtered and dried to obtain a bimetallic Cr-Co catalyst. The amount of ether used was 16 mL and the amount of petroleum ether used was 16 mL relative to 1 mL of the concentrated solution. The catalyst yield was 68 mol%.

[0071] The catalyst prepared in Example 1 31 P NMR (CDCl3): 15.47 (s).

[0072] Example 2

[0073] (1) Under nitrogen protection, 560 mg of CoCl(CO)(PPh2H)2 was mixed with 80 mL of dioxane to obtain a dioxane solution of CoCl(CO)(PPh2H)2 (purple); 600 mg of Cr(CO)6 was mixed with 80 mL of dioxane to obtain a dioxane solution of Cr(CO)6. The dioxane solution of CoCl(CO)(PPh2H)2 was added dropwise to the dioxane solution of Cr(CO)6, and the reaction was stirred at room temperature for 3 h to obtain a complex reaction solution (black purple). The dropping rate of the dioxane solution of CoCl(CO)(PPh2H)2 was 0.5 g / min based on the weight of CoCl(CO)(PPh2H)2 per gram of Cr(CO)6.

[0074] (2) The complex reaction solution is then subjected to vacuum distillation to remove dioxane, and the vacuum distillation is stopped after the weight of the residue no longer changes, to obtain a dark purple oily substance. The oily substance is washed with toluene for several times, and after the color of the toluene no longer changes, the washing liquid is combined as an extract. The extract is filtered through diatomaceous earth to obtain a filtrate, and the filtrate is concentrated to obtain a concentrated solution (5 mL). The total amount of toluene used is 80 mL per gram of the oily substance.

[0075] (3) Ether and petroleum ether were added to the flask containing the concentrated solution, and then the flask was left to stand at -50°C overnight (about 12 hours) to precipitate yellow-green crystals, which were filtered and dried to obtain a bimetallic Cr-Co catalyst. The amount of ether used was 24 mL and the amount of petroleum ether used was 20 mL relative to 1 mL of the concentrated solution. The catalyst yield was 62 mol%.

[0076] Example 3

[0077] The method of Example 1 was followed, except that the tetrahydrofuran in step (1) was replaced by an equal volume of pyridine. The catalyst yield was 25 mol%.

[0078] Example 4

[0079] The method of Example 1 was followed, except that the tetrahydrofuran in step (1) was replaced by an equal volume of diethyl ether. The catalyst yield was 27 mol%.

[0080] Test Example 1

[0081] This test example is used to illustrate the catalytic performance of the catalyst in the hydroformylation reaction of vinyl acetate.

[0082] 5.8 g of vinyl acetate, 0.3 g of the bimetallic center Cr-Co catalyst of Example 1, and 40 mL of toluene were added to a 100 mL reactor, the reactor was closed, nitrogen was replaced three times, synthesis gas was replaced three times, the synthesis gas pressure was 6.0 MPa, and the reaction was heated to 110° C. for 0.5 h. After the reaction was completed, the temperature was cooled to room temperature, the reactor was opened, and the reaction liquid was detected by gas chromatography (GC). The calculated vinyl acetate conversion rate was 92.8%, the aldehyde selectivity was 95.6 mol%, and the selectivity of 3-acetoxypropionaldehyde was 62 mol%.

[0083] Test Example 2

[0084] This test example is used to illustrate the catalytic performance of the catalyst in the hydroformylation reaction of vinyl acetate.

[0085] 5.8 g of vinyl acetate, 0.3 g of the bimetallic center Cr-Co catalyst of Example 1, and 50 mL of toluene were added to a 100 mL reactor, the reactor was closed, nitrogen was replaced three times, synthesis gas was replaced three times, the synthesis gas pressure was 4.5 MPa, and the reaction was heated to 120° C. for 0.5 h. After the reaction was completed, the temperature was cooled to room temperature, the reactor was opened, and the reaction liquid was detected by GC. The calculated vinyl acetate conversion rate was 93.7 mol%, the aldehyde selectivity was 98.2 mol%, and the selectivity of 3-acetoxypropionaldehyde was 63 mol%.

[0086] Test Example 3

[0087] This test example is used to illustrate the catalytic performance of the catalyst in the hydroformylation reaction of vinyl acetate.

[0088] 5.8 g of vinyl acetate, 0.3 g of the bimetallic center Cr-Co catalyst of Example 2, and 50 mL of 1,2-dichloroethane were added to a 100 mL reactor, the reactor was closed, nitrogen was replaced three times, synthesis gas was replaced three times, the synthesis gas pressure was 5.0 MPa, and the reactor was heated to 100 ° C. The reaction time was 1 h. After the reaction was completed, the temperature was cooled to room temperature, the reactor was opened, and the reaction liquid was detected by GC. The calculated vinyl acetate conversion rate was 95.9 mol%, the aldehyde selectivity was 92.3 mol%, and the selectivity of 3-acetoxypropionaldehyde was 66 mol%.

[0089] Test Example 4

[0090] The method of Test Example 1 was followed, except that the catalyst was replaced with an equal weight of the catalyst of Example 3. The vinyl acetate conversion was 91.1 mol%, the aldehyde selectivity was 90.4 mol%, and the selectivity of 3-acetoxypropionaldehyde was 59 mol%.

[0091] Test Example 5

[0092] The method of Test Example 1 was followed, except that the catalyst was replaced with an equal weight of the catalyst of Example 4. The vinyl acetate conversion was 90.7 mol%, the aldehyde selectivity was 91.3 mol%, and the selectivity of 3-acetoxypropionaldehyde was 61 mol%.

[0093] Test Example 6

[0094] This test example is used to illustrate the catalytic performance of the recovered catalyst in the olefin hydroformylation reaction.

[0095] The catalyst in the reaction liquid of Test Example 1 is recovered, wherein the specific process of recovering the catalyst is: filtering the solid catalyst from the reaction liquid, washing the catalyst with toluene, washing it three times with 20 ml of toluene, and then testing the catalytic performance of the recovered catalyst according to the method of Test Example 1.

[0096] The catalyst of recovery test example 1: vinyl acetate conversion rate 91.9 mol%, aldehyde selectivity 95.3 mol%, 3-acetoxypropionaldehyde selectivity 62 mol%.

[0097] Comparative test example 1

[0098] This test example is used to illustrate the catalytic performance of the catalyst Co(CO)8 in the hydroformylation reaction of vinyl acetate.

[0099] The method of Test Example 1 was followed, except that the catalyst was replaced with an equal weight of Co(CO)8. The calculated results showed that the vinyl acetate conversion was 90.8 mol%, the aldehyde selectivity was 89.9 mol%, and the selectivity of 3-acetoxypropionaldehyde was 40 mol%.

[0100] Comparative test example 2

[0101] The method of Test Example 1 was followed, except that the catalyst was replaced with a mixture of equal weights of CoCl(CO)(PPh2H)2 and Cr(CO)6, wherein the molar ratio of Co to Cr in the mixture was 1:1. The calculated vinyl acetate conversion was 67.4 mol%, the aldehyde selectivity was 77.3 mol%, and the selectivity of 3-acetoxypropionaldehyde was 37 mol%.

[0102] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A bimetallic Cr-Co catalyst, characterized in that: The catalyst has a structure shown in formula (1): Wherein, R1 and R2 are each independently selected from C1-C 10 Alkyl, C6-C 15 aryl, -O-R', wherein R' is selected from C1-C 10 Alkyl, C6-C 15 Aryl, C7-C 15 of alkylaryl.

2. A method for preparing a bimetallic Cr-Co catalyst, characterized in that: The method comprises: contacting CoCl(CO)(PR1R2H)2 with Cr(CO)6 to carry out complexation reaction, followed by extraction and crystallization; Wherein, R1 and R2 are each independently selected from C1-C 10 Alkyl, C6-C 15 aryl, -O-R', wherein R' is selected from C1-C 10 Alkyl, C6-C 15 Aryl, C7-C 15 of alkylaryl.

3. The method according to claim 2, wherein: The molar ratio of CoCl(CO)(PR1R2H)2 to Cr(CO)6 is 0.1-3:1, preferably 0.5-1.8:1; And / or, the conditions of the complexation reaction include: temperature of 15-40° C. and time of 0.5-5 h.

4. The method according to claim 2, wherein: The complex reaction is carried out in the presence of a solvent, and the solvent used in the complex reaction is a polar solvent, preferably C2-C 10 The polar organic solvent is preferably a C2-C6 polar organic solvent containing a heteroatom, wherein the heteroatom is at least one of N, O, and S; and further preferably at least one of tetrahydrofuran, dioxane, N,N-dimethylformamide, dimethyl sulfoxide, diethyl ether, and ethyl acetate.

5. The method according to any one of claims 2 to 4, wherein: The process of the complex reaction comprises: mixing a solution containing CoCl(CO)(PR1R2H)2 with a solution containing Cr(CO)6 to carry out a complex reaction; Preferably, the process of the complex reaction comprises: dropping a solution containing CoCl(CO)(PR1R2H)2 into a solution containing Cr(CO)6 to carry out a complex reaction; More preferably, the dripping rate of the solution containing CoCl(CO)(PR1R2H)2 is 0.1-1 g / min, based on the weight of CoCl(CO)(PR1R2H)2 per gram of Cr(CO)6; More preferably, the concentrations of the solution containing CoCl(CO)(PR1R2H)2 and the solution containing Cr(CO)6 are each independently 0.001-0.1 mol / L, preferably 0.002-0.05 mol / L.

6. The method according to claim 5, wherein: The extraction agent used in the extraction is C6-C 15 Aromatics, C1-C 10 Halogenated alkanes and C1-C 10 At least one of ethers, preferably at least one of toluene, benzene, xylene, dichloromethane, chloroform, ethylene glycol diethyl ether and diethyl ether; Preferably, the extraction method is: removing the solvent in the complex reaction liquid to obtain a complex product, then using an extractant to extract the complex product to obtain an extract, then filtering the extract to obtain a filtrate, and then concentrating the filtrate to obtain a concentrated solution.

7. The method according to claim 6, wherein: The crystallization temperature is -60°C to -10°C; Preferably, the crystallization solvent is selected from diethyl ether and / or petroleum ether, more preferably diethyl ether and petroleum ether, wherein the volume ratio of diethyl ether to petroleum ether is 0.01-10:1; More preferably, the amount of the crystallization solvent used is 10-80 mL, preferably 15-50 mL, relative to 1 mL of the concentrate.

8. The catalyst prepared by the method according to any one of claims 2 to 7.

9. Use of the catalyst according to claim 1 or 8 in a hydroformylation reaction.

10. A method for hydroformylation of olefins, characterized in that: The method comprises: contacting an olefin with the catalyst according to claim 1 or 8 for reaction under hydroformylation reaction conditions; Alternatively, the catalyst is prepared according to the method of any one of claims 2 to 7, and then an olefin is contacted with the prepared catalyst under hydroformylation reaction conditions for reaction.

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