1. A catalyst composition comprising at least a water-soluble bisphosphine ligand, a tris (m-sodium sulfophenyl) phosphine ligand, a metal rhodium precursor; further, the rhodium metal precursor is selected from RhCl₃·nH₂O、Rh₂(CH₃COO)₄、Rh(acac)(CO)₂、RhCl(TPPTS)₃、HRh(CO)(TPPTS)₃And HRh (CO)₂(BISGIS), preferably Rh (acac) (CO)₂、HRh(CO)(TPPTS)₃And RhCl (TPPTS)₃One or more of the above;

the structure of the water-soluble diphosphine ligand is as follows:

wherein R is selected from H and CH₃，OCH₃。

2. The composition of claim 1, wherein: the water-soluble diphosphine ligand is a compound containing the following structure:

3. the composition of claim 2, wherein: the water-soluble diphosphine ligand is a compound containing the following structure:

4. the catalyst composition of claim 1, wherein the molar ratio of the water-soluble diphosphine ligand to the tris (m-sodium sulfophenyl) phosphine ligand is 1-5: 1; the molar ratio of the total ligand to rhodium is 2-20: 1.

5. a method for preparing aldehyde compounds by hydroformylation of vegetable oil is characterized in that: use of the catalyst composition of any one of claims 1 to 5.

6. The method of claim 5, wherein: it comprises the following contents:

(1) a catalyst composition, a co-solvent, and water; (2) esterifying the vegetable oil; (3) synthesis gas; (4) the total pressure of the synthesis gas is 10bar to 50bar at the temperature of between 90 and 140 ℃; (5) after the reaction is finished, carrying out oil-water phase separation, taking the oil phase to obtain an aldehyde crude product, and recycling the water phase for continuous catalytic reaction;

the cosolvent is one or more selected from ethers, low carbon alcohols, cyclodextrins, amides and hydrogels.

7. The method of claim 6, wherein: the ether is selected from one or more of PEG-200, PEG-400, PEG-600, PEG-800 and PEG-20000; the low-carbon alcohol is selected from one or more of methanol, ethanol, isopropanol and butanol; the cyclodextrin is selected from one or more of alpha-cyclodextrin, beta-cyclodextrin, gamma-cyclodextrin, methylated alpha-cyclodextrin, methylated beta-cyclodextrin and methylated gamma-cyclodextrin; the amide is selected from one or more of formamide, N-methylformamide and N, N-dimethylformamide; the hydrogel is selected from cross-linked compounds of PEG-20000 and alpha-cyclodextrin and methylated beta-cyclodextrin; furthermore, the cosolvent is preferably one or more of a long carbon chain polyethylene glycol compound, methylated beta-cyclodextrin, N-methylformamide and a hydrogel compound.

8. The method of claim 6, wherein: the concentration of rhodium in the rhodium precursor in the water phase is 200 ug/ml-400 ug/ml; the molar ratio of esterified vegetable oil to rhodium is between 100 and 3000: 1.

9. the method of claim 6, wherein: the volume ratio of water to liquid cosolvent is 5:1 to 5: 8; furthermore, the concentration of the solid cosolvent is 1-20 mmol/L.

10. The method of claim 7, wherein: the vegetable oil is selected from one or more of soybean oil, rapeseed oil, peanut oil, corn oil, palm oil, olive oil and castor oil; further, the esterification is selected from methyl esterification or ethyl esterification.

Background

At present, after the double-carbon target of 30.60 carbon peak reaching and carbon neutralization is clear, green development is promoted, and green transformation is accelerated to become the strategic requirement of high-quality development of the chemical industry in the future. Advocate the renewable resource utilization, save energy and reduce emission and the development of environment-friendly degradable materials, and is the main way to realize the development of green environmental protection. The polyol obtained by modifying the natural vegetable oil serving as the raw material is a green and environment-friendly new product and can replace increasingly reduced petroleum resources.

Vegetable oils are unsaturated oil compounds containing at least one carbon-carbon double bond, and include glycerol, methyl oleate, methyl linoleate, methyl linolenate, methyl ricinoleate, and the like. The hydroformylation method is adopted to modify the vegetable oil to prepare corresponding aldehyde compounds, and the compounds containing double functional groups such as primary hydroxyl, amido, carboxyl and the like are further derived and synthesized, and can be directly used as paint, high-grade lubricating oil and plasticizer, or used as new polymerization monomers to prepare polymer materials such as polyurethane, polyester, polyamide and the like with special performance.

Hydroformylation since the discovery of Otto Roelen in 1938, a variety of phosphine ligands with high activity and selectivity, particularly monophosphine and diphosphine ligands of phosphonites and phosphoramidites, have been developed in succession in the field of rhodium-catalyzed hydroformylation of vegetable oils, but phosphonites and phosphoramidites are unstable and are susceptible to decomposition or oxidation and loss of activity during hydroformylation of vegetable oils catalyzed in combination with a rhodium precursor. Meanwhile, products synthesized based on the vegetable oil carbonyl can be separated from the rhodium catalyst by a high-temperature distillation method, and the regeneration process of the phosphonite and phosphoramidite ligands is complex, high in energy consumption and high in cost, so that the industrial production is difficult to realize.

Patent CN110423250A describes a pincerlike diphosphine ligand for catalyzing unsaturated oil hydroformylation, and although such pincerlike diphosphine ligand has stable structure and high catalytic activity and selectivity, aldehyde synthesized by unsaturated oil carbonyl still needs to be separated from catalyst by high temperature distillation, and at the same time, during the high temperature distillation process, activity and life cycle of rhodium catalyst are seriously affected. Although the method is also used in the field of vegetable oil hydroformylation, the process is a homogeneous reaction, and the problem of separating the product aldehyde from the catalyst is difficult to realize.

Patent CN110981709B discloses a novel water-soluble diphosphine ligand for catalyzing the hydroformylation of C4-C12 internal olefins, which has the advantage that ligands containing multiple coordination sites can be complexed with rhodium to form a stable water-soluble rhodium catalyst, thereby improving the selectivity of C4-C12 internal olefin hydroformylation products. The defect is that after the ligand is complexed with rhodium, the space structure around the central metal rhodium is crowded, and the binding capacity of the vegetable oil olefin with longer carbon chain and the central metal rhodium is weakened, so that the problem of low activity of the vegetable oil hydroformylation reaction is difficult to solve.

In recent years, in order to reduce the cost of separating the product from the catalyst, the process flow is simplified and the catalyst is convenient to recycle. The method adopts active carbon nano mesoporous as an interface additive, and catalyzes methyl oleate in a catalyst water solution consisting of water-soluble phosphine ligand TPPTS and rhodium precursor Rh (acac) (CO)2 to obtain 90% aldehyde (50bar, 80 ℃, 24 h). However, during the reaction, nano activated carbon is easily dispersed into the organic phase, which leads to difficult phase separation and further affects the quality of the product, and thus, it is difficult to realize industrial production (Boulanger, j., Ponchel, a., Bricout, h., Hapiot, f., Monflier, e., eur.j. liped sci.technol.2012,114, 1439-1446). Later on, cyclodextrin was used instead of activated carbon, but for long carbon chain methyl oleate with low water solubility, mass transfer limitation resulted in lower reactivity of the two-phase catalytic system, i.e. only 25% conversion of methyl oleate and 55% selectivity of aldehyde under the reaction conditions of 50bar and 80 ℃ (Potier, j., Menuel, s., Mon flier, e., hapitot, f., ACS catal.2014,4, 2342-.

In the process of catalyzing the hydroformylation reaction of methyl oleate by a water-soluble phosphine ligand (TPPTS) and a rhodium catalyst, the professor Thomas Seidensticker of Germany university of Dutmond utilizes water and butanol or isopropanol as cosolvent to improve the activity of two-phase catalytic reaction and the phase separation speed of two phases. However, rhodium in the aqueous phase is lost to the product phase, and further, the activity of the catalyst aqueous solution is gradually reduced or lost in the catalytic circulation process, so that the industrial production is difficult to realize.

Disclosure of Invention

The invention provides a method capable of avoiding the problems, which solves the separation problem of the product aldehyde and the catalyst after the hydroformylation of vegetable oil ester by adopting a water-soluble diphosphine ligand and reduces the separation cost of the product aldehyde and the catalyst after the hydroformylation of vegetable oil ester; the problem of low reaction speed of the water/organic two-phase catalytic vegetable oil hydroformylation is solved by adding the water-soluble monophosphine ligand. By adopting a catalytic system consisting of the novel aqueous solution diphosphine ligand and the rhodium catalyst, the activity of the water/organic two-phase catalytic reaction is improved, the problem that the rhodium catalyst runs off to a product phase is solved, and the water-soluble ligand is stable and can stabilize the activity of the rhodium catalyst, so that the aqueous solution of the catalyst can be continuously recycled and is suitable for industrial production and application.

Specifically, the invention provides a water-soluble diphosphine ligand shown as a formula I:

wherein R is selected from H and CH₃，OCH₃。

Further, a compound having the structure:

wherein, the compound comprises the following structure:

the research of the invention finds that the water-soluble diphosphine ligand can exert the optimal catalytic effect only by being combined with the tri (m-sodium sulfophenyl) phosphine ligand, which is not only beneficial to improving the reaction rate of plant hydroformylation, but also can stabilize rhodium metal and prevent the rhodium metal from losing.

In the experiment, the water-soluble diphosphine ligand is also used in combination with water-soluble monophosphine ligands TPPMS and TPPDS respectively, but compared with tris (m-sodium sulfophenyl) phosphine ligand (TPPTS), the catalysis effect is poor after the coordination of TPPMS and TPPDS (the conversion rate of methyl oleate is lower than 50%).

Accordingly, the present invention also provides a catalyst composition comprising at least the aforementioned water-soluble bisphosphine ligand, tris (m-sodium sulfophenyl) phosphine ligand, metal rhodium precursor.

Further, the rhodium metal precursor is selected from rhodium compounds and rhodium complexes, for example, RhCl can be selected₃·nH₂O、Rh₂(CH₃COO)₄、Rh(acac)(CO)₂、RhCl(TPPTS)₃、HRh(CO)(TPPTS)₃And HRh (CO)₂(BISGIS), preferably Rh (acac) (CO)₂、HRh(CO)(TPPTS)₃And RhCl (TPPTS)₃One or more of them.

Wherein the molar ratio of the water-soluble diphosphine ligand to the tri (m-sodium sulfophenyl) phosphine ligand is 1-5: 1; the molar ratio of the total ligand to rhodium is 2-20: 1.

the invention also provides a method for preparing aldehyde compounds by hydroformylation of vegetable oil, wherein the catalyst composition is used.

Specifically, the method comprises the following steps:

(1) a catalyst composition, a co-solvent, and water; (2) esterifying the vegetable oil; (3) synthesis gas; (4) the total pressure of the synthesis gas is 10bar to 50bar at the temperature of between 90 and 140 ℃; (5) after the reaction is finished, oil and water are subjected to phase splitting, an aldehyde crude product is obtained from the oil phase, and the water phase is recovered and continuously used for catalytic reaction.

The operation steps are as follows:

(1) adding a rhodium catalyst, a water-soluble sulfonate diphosphine ligand, a cosolvent and deionized water into a reactor;

(2) replacing air in the reactor with high-purity nitrogen, and then adding vegetable oil and synthesis gas (CO + H)₂) Introducing the mixture into a reactor, and reacting for 3-10 h at the temperature of 90-140 ℃ under the condition that the total pressure of the synthesis gas is 10-50 bar;

(3) introducing the mixture of the catalyst aqueous solution and the crude aldehyde after the reaction into a phase separator for static phase separation, returning the catalyst aqueous solution at the lower layer into the reactor, and continuing to react with the vegetable oil and the synthetic gas (CO + H)₂) Catalytic reaction is carried out, and the upper layer is oil-phase crude aldehyde.

Wherein the cosolvent is selected from one or more of ethers, low carbon alcohols, cyclodextrins, amides and hydrogels. For example, the ether is selected from one or more of PEG-200, PEG-400, PEG-600, PEG-800 and PEG-20000; the low-carbon alcohol is selected from one or more of methanol, ethanol, isopropanol and butanol; the cyclodextrin is selected from one or more of alpha-cyclodextrin, beta-cyclodextrin, gamma-cyclodextrin, methylated alpha-cyclodextrin, methylated beta-cyclodextrin and methylated gamma-cyclodextrin; the amide is selected from one or more of formamide, N-methylformamide and N, N-dimethylformamide; the hydrogels are selected from cross-linked compounds of PEG-20000 with alpha-cyclodextrin and methylated beta-cyclodextrin.

Furthermore, the cosolvent can be one or more selected from long carbon chain polyethylene glycol compounds, methylated beta-cyclodextrin, N-methylformamide and hydrogel compounds.

Wherein, the concentration of rhodium in the rhodium precursor in the water phase is 200 ug/ml-400 ug/ml; the molar ratio of esterified vegetable oil to rhodium is between 100 and 3000: 1.

wherein, if the cosolvent is liquid, the volume ratio of the water to the liquid cosolvent is 5:1 to 5: 8.

Wherein, if the cosolvent is solid, the concentration of the solid cosolvent is 1-20 mmol/L.

Wherein the vegetable oil is selected from one or more of soybean oil, rapeseed oil, peanut oil, corn oil, palm oil, olive oil and castor oil.

Wherein the esterification is selected from methyl esterification or ethyl esterification.

Further, the esterified vegetable oil may be selected from one or more of methyl esterified soybean oil, methyl esterified rapeseed oil, methyl esterified palm oil and methyl esterified castor oil.

In the present invention, the esterified vegetable oil can be obtained by purchasing a commercially available product, or can be prepared by a conventional esterification reaction.

The catalyst provided by the invention is applied to a method for preparing fatty aldehyde by vegetable oil hydroformylation, and the conversion rate of methyl oleate is high. The invention has the beneficial effects that:

(1) the invention uses water/organic two-phase hydroformylation method to catalyze vegetable oil to prepare corresponding aldehyde compounds, and can further derive and synthesize bifunctional compounds containing primary hydroxyl, amido, carboxyl and the like, and the compounds can be directly used as coatings, high-grade lubricating oil and plasticizers, or can be used as new polymerization monomers to prepare polymer materials with special properties, such as polyurethane, polyester, polyamide and the like. The raw material vegetable oil is a renewable resource, and the product is a green, environment-friendly and environmentally-friendly degradable material, accords with the development mode of ecological cycle economy, and is one of production modes for reducing carbon emission;

(2) the water-soluble diphosphine ligand adopted by the invention has good stability and strong anti-poisoning capability, is not easy to oxidize and decompose, and simultaneously can well stabilize the rhodium catalyst based on the structural characteristic that the water-soluble diphosphine ligand contains a plurality of coordination sites, thereby reducing the loss of the rhodium catalyst in the production process. The catalytic system of the water-soluble mixed phosphine ligand and rhodium precursor combination has high stability and long service life, thereby avoiding using excessive ligand to stabilize the rhodium catalyst, wherein the usage amount of the mixed ligand is respectively as follows: the content of diphosphine ligand is 0.05-0.4 wt%, the content of monophosphine ligand is 0.05-0.5 wt%, which is far lower than the 5-8 wt% ligand used in industrial production, thus reducing production cost and improving production efficiency;

(3) the invention adopts a method for preparing aldehyde compounds by using water/organic two-phase catalytic vegetable oil hydroformylation, utilizes a catalyst system formed by combining a water-soluble phosphine ligand, a rhodium compound and a cosolvent, and naturally separates phases (the upper layer is a product phase, and the lower layer is a catalyst water phase) after the reaction is finished, wherein the ligand, the rhodium catalyst and the cosolvent are in the water phase, the product and the catalyst are simply separated, the catalyst and the product can be completely separated without a high-temperature distillation method, the separation process is simple, and the production cost is low.

Detailed Description

The present invention is described in detail below with reference to examples, which are provided for the purpose of further illustration only and are not to be construed as limiting the scope of the present invention, and non-essential modifications and adaptations thereof by those skilled in the art based on the foregoing disclosure will still fall within the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or equipment used are conventional products available commercially, not indicated by the manufacturer.

The term "comprises" or "comprising" in this specification means that it may include or contain other components in addition to the components described, and the term "comprising" or "comprises" may be replaced with the term "is" or "consists of … …" in the closed form.

The method for analyzing and detecting the vegetable oil hydroformylation products comprises the steps of identifying the hydroformylation products as corresponding aldehydes through nuclear magnetic identification and high-resolution mass spectrometry, carrying out quantitative analysis on the hydroformylation products by Agilent GC-8860 gas chromatography, and carrying out SE-30, psi 0.25 x 30mm and hydrogen flame detector on a capillary column.

Example 1 hydroformylation of methyl oleate

(1) Preparing methyl oleate, namely adding 600g of soybean oil, 5.4g of potassium hydroxide and 180ml of methanol into a 1000ml three-neck round-bottom flask in sequence, carrying out reflux reaction for 3 hours under mechanical stirring, cooling to room temperature, introducing the mixed solution into a 1000ml separating funnel, carrying out phase separation, wherein the lower layer is brown alkaline-containing glycerol liquid, and the upper layer is a colorless transparent methyl oleate mixture, and obtaining the methyl oleate through gas chromatography analysis: the content of methyl oleate containing one carbon-carbon double bond is 54 percent, the content of methyl linoleate containing two carbon-carbon double bonds is 21 percent, and the content of methyl linolenate containing three carbon-carbon double bonds is 5 percent.

(2) Hydroformylation, 16mg of Rh (acac) (CO)2, 50mg of water-soluble bisphosphine ligand, 32mg of tris (m-sulfophenyl) phosphine ligand, 305mg of methylated β -cyclodextrin were added in succession to a 50ml autoclave, 25ml of deionized water, 5ml of methyl oleate were added. Then, the synthesis gas is filled for replacing three times, the synthesis gas is filled again to 20bar (the volume ratio of the hydrogen to the carbon monoxide is 1:1.1), stirring is started, the temperature is slowly raised to 120 ℃, and timing is carried out; after the reaction is finished for 5 hours, the high-pressure reaction kettle is placed in ice water to be rapidly cooled to room temperature, the gas in the reaction kettle is emptied, all reaction liquid is taken out, the liquid is observed to be divided into an upper layer and a lower layer, the lower layer is yellow catalyst aqueous solution, the upper layer is oil phase, and the chromatographic analysis is carried out, so that the yield of the aldehyde is 94%.

(3) The reaction equation is as follows:

wherein the ligands used are:

example 2 hydroformylation of methyl linoleate

Methyl linoleate hydroformylation was carried out in the same manner as in example 1 except that the reaction pressure was 50bar, the reaction time was 8 hours, and the yield of the dialdehyde compound was 80% by gas chromatography. The reaction equation is as follows:

wherein the ligands used are:

comparative example 1 hydroformylation of methyl linoleate

To a 50ml autoclave were added, in order, 16mg of Rh (acac) (CO)2, 50mg of a water-soluble bisphosphine ligand, 305mg of methylated β -cyclodextrin, 25ml of deionized water, 5ml of methyl linoleate. Then, the synthesis gas is filled for replacing three times, the synthesis gas is filled again to 50bar (the volume ratio of the hydrogen to the carbon monoxide is 1:1.1), stirring is started, the temperature is slowly raised to 120 ℃, and timing is carried out; after the reaction is finished for 8 hours, the high-pressure reaction kettle is placed in ice water to be rapidly cooled to room temperature, the gas in the reaction kettle is emptied, all reaction liquid is taken out, the liquid is observed to be divided into an upper layer and a lower layer, the lower layer is yellow catalyst aqueous solution, the upper layer is oil phase, and chromatographic analysis is carried out, so that the yield of the dialdehyde compound is 44%.

Comparative example 2 hydroformylation of methyl linoleate

Methyl linoleate hydroformylation was carried out in the same manner as in comparative example 1, except that 32mg of tris (m-sulfophenyl) phosphine ligand was used as the water-soluble ligand. After the reaction, the liquid was observed to be divided into upper and lower layers, the lower layer was a black aqueous catalyst solution, and the upper layer was an oil phase, and the yield of the dialdehyde compound was 61%.

Comparative example 3 comparison of catalyst stability test in hydroformylation of methyl linoleate

The upper oil phase after the reaction of example 2 and comparative examples 1 to 2 was sampled, and the rhodium content in the oil phase was measured by ICP-MS while observing the color change of the lower water phase. See table 1.

Table 1:

note: the catalytic activity is obviously improved by using the diphosphine ligand and the monophosphine ligand in combination as shown in the comparative example 1 and the example 2.

As can be seen from the comparison of the data in Table 1, under the same experimental conditions, when only the water-soluble diphosphine ligand is adopted, the rhodium in the catalytic aqueous solution is extremely low in loss to the oil phase, and is only 20-30ppb, so that the diphosphine ligand has very strong capability of combining metal rhodium on the molecular level; under the same experimental conditions, when the tri (m-sodium sulfophenyl) phosphine ligand is singly used, the yield of dialdehyde is higher than that when the diphosphine ligand is singly used, but the amount of rhodium in a water phase which is lost to an oil phase is very high and reaches 517ppb, because the metal rhodium is combined by the monophosphine ligand in a weak capacity, the stability of the rhodium catalyst is weakened, the rhodium catalyst is easily decomposed to cause the color of the catalyst water solution to be darker (black), and further, a multi-carbonyl metal rhodium compound is easily formed and dissolved in the oil phase to finally cause the low catalytic activity and the inactivation; under the same experimental conditions, the combination of the water-soluble diphosphine ligand and the tri (m-sodium sulfophenyl) phosphine ligand is adopted, so that the loss of the rhodium catalyst is reduced, and the yield of dialdehyde is also improved; on the other hand, the water-soluble diphosphine ligand and the tri (m-sodium sulfonate phenyl) phosphine ligand generate a synergistic effect, and the selectivity of the vegetable oil hydroformylation product is improved together.

Example 3 hydroformylation of methyl ricinoleate

(1) The preparation of methyl ricinoleate is carried out by adding 506g castor oil, 4g potassium hydroxide and 180ml methanol into 1000ml three-neck round-bottom flask, reflux reacting for 1.5 hours under mechanical stirring, cooling to room temperature, introducing the mixed solution into 1000ml separating funnel, phase separating, wherein the lower layer is brown alkaline-containing glycerol liquid, the upper layer is colorless transparent methyl ricinoleate, and gas chromatography analysis shows that the purity of methyl ricinoleate is 90%, and the rest is saturated methyl oleate.

(2) Hydroformylation, 16mg of Rh (acac) (CO)2, 50mg of water-soluble bisphosphine ligand, 32mg of tris (m-sulfophenyl) phosphine ligand, 305mg of methylated beta-cyclodextrin are added in succession to a 50ml autoclave, 25ml of deionized water and 5ml of methyl ricinoleate are added. Then, the synthesis gas is filled for replacing three times, the synthesis gas is filled again to 20bar (the volume ratio of the hydrogen to the carbon monoxide is 1:1.1), stirring is started, the temperature is slowly raised to 120 ℃, and timing is carried out; after the reaction is finished for 5 hours, the high-pressure reaction kettle is placed in ice water to be rapidly cooled to room temperature, the gas in the reaction kettle is emptied, all reaction liquid is taken out, the liquid is observed to be divided into an upper layer and a lower layer, the lower layer is a yellow catalyst aqueous solution, the upper layer is an oil phase, and the chromatographic analysis is carried out, so that the yield of the aldehyde is 88%.

(3) The reaction equation is as follows:

wherein the ligands used are:

example 4 hydroformylation of methyl ricinoleate

The procedure of example 3 was followed, except that a water-soluble phosphine ligand was used as the ligand 2, and the yield of aldehyde after the completion of the reaction was 72%.

Wherein the ligand structure is as follows:

example 5 preparation of aldehydes by hydroformylation of Soybean oil

To a 50ml autoclave were added in sequence 16mg of Rh (acac) (CO)₂50mg of water-soluble bisphosphine ligand, 32mg of tris (m-sulfophenyl) phosphine ligand, 305mg of methylated beta-cyclodextrin, 25ml of deionized water, 5.3g of soybean oil were added. Then, synthetic gas is filled for replacing three times, the synthetic gas is filled again to 50bar, stirring is started, the temperature is slowly raised to 130 ℃, and timing is carried out; after the reaction is finished for 5 hours, the high-pressure reaction kettle is placed in ice water to be rapidly cooled to room temperature, the gas in the reaction kettle is emptied, all reaction liquid is taken out, the liquid is observed to be divided into an upper layer and a lower layer, the lower layer is yellowThe nuclear magnetic analysis of the colored aqueous catalyst solution, the upper oil phase, found that the yield of aldehyde was 85%.

The reaction equation is as follows

Wherein the ligands used are:

example 6

The procedure of example 5 was followed except that a co-solvent methylated beta-cyclodextrin was used as a hydrogel for hydroformylation of soybean oil.

(1) Hydrogel preparation, 1.8g of alpha-cyclodextrin, 1.2mg of PEG-20000 and 18ml of deionized water were sequentially added to a 50ml autoclave. Then, the air in the reaction kettle is replaced by nitrogen, and the reaction kettle is stirred for 30 minutes at the temperature of 80 ℃ and then cooled to room temperature, so that the transparent hydrogel can be obtained.

(2) Hydroformylation of Soybean oil to the hydrogel prepared above was added 16mg of Rh (acac) (CO)₂50mg of water-soluble bisphosphine ligand, 32mg of tris (m-sulfophenyl) phosphine ligand, 305mg of methylated beta-cyclodextrin, 5.3g of soybean oil. Then, synthetic gas is filled for replacing three times, the synthetic gas is filled again to 50bar, stirring is started, the temperature is slowly increased to 120 ℃, and timing is carried out; after the reaction is finished for 5 hours, the high-pressure reaction kettle is placed in ice water to be rapidly cooled to room temperature, the gas in the reaction kettle is emptied, all reaction liquid is taken out, the liquid is observed to be divided into an upper layer and a lower layer, the lower layer is yellow catalyst aqueous solution, the upper layer is oil phase, nuclear magnetic analysis is carried out, and the yield of aldehyde is measured to be 94%.

Example 7

The hydroformylation of castor oil was carried out in the same manner as in example 6, except that the molecular structure of castor oil was a compound having a hydroxyl group, and castor oil had a certain hydrophilicity in the hydroformylation catalytic reaction process as compared with soybean oil. Therefore, the yield of aldehyde reached 99% in 5 hours of reaction.

The reaction equation is as follows:

wherein the ligands used are:

example 8 recycle experiment of Castor oil hydroformylation reaction

The cycling experiment was performed according to the procedure of example 7, with the following specific steps:

(1) discharging, stopping stirring after the hydroformylation reaction is finished, slowly cooling to room temperature, taking out an upper oil phase in the kettle by using a sampling pipeline of the reaction kettle through pressure difference, and performing gas chromatography;

(2) feeding materials, after the oil phase sample is extracted, emptying the gas in the kettle in a fume hood, injecting 5ml of castor oil into the kettle from a sampling port of the reaction kettle by using a 10ml injector, and then displacing the air in the kettle by using synthesis gas;

(3) the reaction, the reaction procedure was as in example 8.

According to the operation steps, 10 times of catalytic cycle experimental investigation is carried out, the yield of the aldehyde is basically maintained to be more than 95%, the performance of the catalyst is stable, after 10 times of cycle, the color of the catalyst aqueous solution in the reaction kettle is yellow, the rhodium content in the aqueous solution is still 250ppm (ug/ml) by ICP-MS analysis, and meanwhile, the rhodium content in the product aldehyde (10 times of accumulated oil phase) is detected to be 30ppb (ug/L). Therefore, the loss of rhodium in the catalyst aqueous solution is extremely low, and the combination of the water-soluble diphosphine ligand and the tri (m-sulfophenyl) phosphine ligand can stabilize the rhodium catalyst in the aqueous solution and keep the catalytic activity of the rhodium catalyst unchanged.

The experimental result shows that the combination of the water-soluble diphosphine ligand and the tri (m-sulfophenyl) phosphine ligand and the rhodium catalyst combination system has good stability, and the problem of rhodium loss is solved by using the novel water-soluble diphosphine ligand. In the process of recycling the catalyst, the catalyst and the product can be simply separated by phase without high-temperature distillation and activation treatment, and the catalyst aqueous solution is continuously recycled.