Catalyst for olefin hydroformylation reaction and method for preparing isovaleraldehyde

Abstract

The invention relates to the technical field of olefin hydroformylation reaction, and discloses a catalyst for olefin hydroformylation reaction and a method for preparing isovaleraldehyde. The catalyst is a coordination compound and comprises an active center and a ligand, wherein the active center is from hexadecacarbonyl hexa rhodium, and the ligand is from phosphite ester; in the catalyst, the molar ratio of the element P to the element Rh is (4-10): 1. The catalyst provided by the invention can efficiently catalyze an isobutene hydroformylation reaction to prepare isovaleraldehyde, the catalyst has long-term operation stability in the reaction, the conversion rate of isobutene in the first reaction can be greater than 97%, the selectivity of isovaleraldehyde is greater than 97%, and the catalyst can be recycled for not less than 10 times in the isobutene hydroformylation reaction, so that the catalyst has a wide application prospect in the isobutene hydroformylation reaction. And preferably, the material can be recycled for 30 times.

Description

Technical Field

[0001] The present invention relates to the technical field of olefin hydroformylation reaction, and in particular to a catalyst for olefin hydroformylation reaction and a method for preparing isovaleraldehyde. Background Art

[0002] Hydroformylation reaction, also known as carbonyl synthesis reaction, refers to the reaction of olefins with carbon monoxide and hydrogen in the presence of transition metal catalysts, especially cobalt and rhodium catalysts, to convert olefins into aldehydes with one carbon added. Aldehydes, as an important intermediate in the chemical industry, have important industrial applications, so hydroformylation has developed into one of the most important industrial catalytic reactions to date.

[0003] Isovaleraldehyde is an important chemical raw material. There are two main processes for preparing isovaleraldehyde in industry, one is oxidation or catalytic dehydrogenation, and the other is isobutylene hydroformylation process. The industrialized liquid phase oxidation method in the former has unfavorable factors such as serious equipment corrosion, large environmental pollution, and many side reactions due to the use of catalysts such as sulfuric acid, dichromate, and manganese oxide; the catalytic dehydrogenation method such as CN1261399C uses a brass catalyst to catalyze the dehydrogenation of isoamyl alcohol to prepare isovaleraldehyde, and the reaction temperature is 400-500°C. The catalyst is easily deactivated by carbon deposition at high temperature, and the energy consumption is high. The process of preparing isovaleraldehyde by isoamyl alcohol oxidation or catalytic dehydrogenation of isoamyl alcohol is facing the problem of being gradually eliminated, and is replaced by the isobutylene hydroformylation process to prepare isovaleraldehyde.

[0004] CN1235853C discloses a method for preparing isovaleraldehyde from isobutylene, wherein isobutylene is used as the starting material, in the presence of a rhodium catalyst, an inert gas is passed through the system to remove all air, and then a mixed gas of CO and H2 in a volume ratio of 1:1 is passed through to carry out a hydroformylation reaction. In this method, water-soluble triphenylphosphine ligand-modified rhodium is used as the catalyst.

[0005] CN106008184A discloses a method for preparing 3-methylbutyraldehyde from isobutylene. The method uses isobutylene and synthesis gas as raw materials, triphenylphosphine carbonyl rhodium acetylacetonate as a catalyst, triphenylphosphine as a ligand, and n-decane as a solvent to carry out a hydroformylation reaction to prepare isovaleraldehyde.

[0006] CN106431869A discloses a method for producing aldehydes by hydroformylation of olefins. Under the conditions of reaction temperature of 60-130°C and reaction pressure of 1.0-6.0MPa, aldehyde is used as solvent, and a rhodium compound, a phosphorus compound containing an o-methylphenyl group, a hard base pentavalent phosphorus oxide, and a bidentate phosphite composition catalyze the hydroformylation reaction of olefins with CO and H2 to synthesize aldehydes.

[0007] CN111085198A discloses a hydroformylation catalyst, comprising an active component and a carrier for carrying the active component, wherein the active component comprises a first active component, a second active component and a third active component, wherein the first active component is Rh and / or an oxide of Rh, the second active component is at least one metal selected from the group consisting of Ir, Ru, Os, Pt and Pd and / or an oxide of the metal, and the third active component is at least one metal selected from the group consisting of Mo, Zn, Mn, Fe, Co, V and Cu and / or an oxide of the metal. The scheme also relates to the use of the hydroformylation catalyst in the hydroformylation reaction of isobutylene to generate isovaleraldehyde.

[0008] CN112010906A discloses a bisphosphite and a preparation method and application thereof, wherein a homemade specific bisphosphite is combined with a transition metal for olefin hydroformylation, olefin isomerization hydroformylation, olefin alkoxycarbonylation, olefin hydrocarboxylation or olefin hydrocyanation.

[0009] The above hydroformylation processes for preparing isovaleraldehyde all have the problems of poor catalyst operation stability and complex catalyst preparation process. It is urgent to develop a catalyst with a simple preparation process and the ability to maintain long-term operation stability in the isobutylene hydroformylation reaction. Summary of the invention

[0010] Aiming at the problems that the existing catalyst for olefin hydroformylation reaction has poor operation stability and complicated preparation process, the present invention provides a catalyst for olefin hydroformylation reaction and a method for preparing isovaleraldehyde.

[0011] To achieve the above object, the first aspect of the present invention provides a catalyst for olefin hydroformylation reaction, wherein the catalyst is a coordination compound, comprising an active center and a ligand; wherein the active center is derived from hexadecyl hexarhodium, and the ligand is derived from phosphite;

[0012] In the catalyst, the molar ratio of element P:element Rh is (4-10):1.

[0013] The second aspect of the present invention provides a method for preparing isovaleraldehyde, comprising: in the presence of a catalyst and a solvent, subjecting isobutylene to a hydroformylation reaction with synthesis gas to obtain isovaleraldehyde;

[0014] Wherein, the catalyst is the catalyst described in the first aspect above.

[0015] Through the above technical solution, compared with the prior art, the present invention can achieve the following beneficial effects:

[0016] (1) The catalyst provided by the present invention has an active center of a carbonyl rhodium cluster compound with an adjustable electronic effect and high stability, thereby avoiding the instability of the carbonyl rhodium monomer and achieving the stability of the catalyst in the long-term operation during the olefin hydroformylation reaction. After the reaction, the product is separated by distillation, and the high boiling liquid containing the catalyst is directly recycled back to the reaction system to continue the catalytic reaction, which can be continuously applied and reduce production costs. The catalyst can be recycled for no less than 10 times in the isobutylene hydroformylation reaction, and preferably can be recycled for up to 30 times.

[0017] (2) By adjusting the ratio of phosphine to rhodium in the catalyst, efficient and highly selective hydroformylation of isobutylene can be achieved, and the isobutylene conversion rate in the first reaction can be greater than 97%, and the isovaleraldehyde selectivity can be greater than 97%.

[0018] (3) The catalyst preparation process is simple and easy to operate, without the need for special steps and conditions. 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 catalyst for olefin hydroformylation reaction, wherein the catalyst is a coordination compound, comprising an active center and a ligand; wherein the active center is derived from hexadecyl hexarhodium, and the ligand is derived from phosphite;

[0021] In the catalyst, the molar ratio of element P:element Rh is (4-10):1.

[0022] In the hydroformylation reaction of olefins, the rhodium precursor used in the catalyst is usually dicarbonyl acetylacetonate rhodium, tri(triphenylphosphine)carbonyl hydrogenated rhodium, acetylacetonate triphenylphosphine carbonyl rhodium, etc., which needs to be replaced with the phosphine ligand to free acetylacetone or triphenylphosphine to start the reaction. The active intermediate of the actual catalytic reaction is HRhLn(CO)m, where L is a phosphine ligand, the coordination number n is 1-2, and the coordination number m of carbon monoxide is 2-3. These catalysts will generate binuclear rhodium clusters during the long-term operation of the catalytic reaction, affecting the stability of the catalyst. The inventors of the present invention have found in their research that directly using hexadecyl hexarhodium and mixing it with appropriate phosphine ligands in a certain ratio to form a catalyst can efficiently catalyze the hydroformylation reaction of olefins, and the catalyst has long-term operation stability in the reaction.

[0023] According to the present invention, in the catalyst, hexadecyl hexarhodium (CAS: 28407-51-4) provides the active center of the catalyst. Hexadecyl hexarhodium is a stable carbonyl metal atom cluster compound, having a hexacoordinated regular octahedral Oh coordination configuration (coordination number is 6, ligands are connected to the central ion through coordination bonds to form a regular octahedral structure), wherein rhodium has two carbonyl ligands CO (T) and CO (L), and due to its various coordination modes, it can be replaced by the coordination of the carbon monoxide ligand through the complex coordination of the electron-rich phosphine ligand, and the electronic properties of the periphery of the rhodium atom are adjusted, thereby improving the carbonylation activity of the rhodium atom in the catalyst center.

[0024] In the present invention, the source of hexadecyl hexarhodium is not limited, and it can be prepared by using rhodium trichloride as a raw material using a known method, or it can be a commercially available product.

[0025] According to the present invention, in the catalyst, preferably, the molar ratio of the element P from the ligand: the element Rh from the active center is (5-8):1, which is more conducive to improving the reaction rate and product selectivity.

[0026] According to the present invention, in the catalyst, the source of the phosphite and the specific species selection are relatively broad, and the phosphite can be obtained by self-production using conventional methods, or by using common commercial brands.

[0027] According to the present invention, in the catalyst, preferably, the phosphite is selected from monophosphite and / or diphosphite, which can accelerate the complexation between the active center rhodium and the ligand (faster than the complexation between rhodium and triphenylphosphine), and the spatial configuration of the complex is more conducive to improving the reaction conversion rate and reaction selectivity.

[0028] In the present invention, preferably, the monophosphite can be selected from at least one of triphenyl phosphite (CAS: 101-02-0), tri(2-tert-butyl-4-methylphenyl)phosphite (CAS: 21177-86-6) and tri(2,4-di-tert-butylphenyl)phosphite (CAS: 31570-04-4).

[0029] More preferably, the monophosphite is tris(2,4-di-tert-butylphenyl) phosphite.

[0030] In the present invention, preferably, the bisphosphite can be selected from 6,6'-[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[D,F][1,3,2]dioxaphosphinane (CAS: 121627-17-6) and / or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite (CAS: 26741-53-7).

[0031] More preferably, the bisphosphite is 6,6'-[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[D,F][1,3,2]dioxaphosphinyl).

[0032] The catalyst provided by the present invention can efficiently catalyze olefin hydroformylation reaction, especially can efficiently catalyze isobutylene and synthesis gas to carry out hydroformylation reaction to prepare isovaleraldehyde. The catalyst has the advantage of being able to operate stably for a long time during the reaction process, can achieve an isobutylene conversion rate of more than 97% and an isovaleraldehyde selectivity of more than 97% in the first reaction, and the catalyst can be recycled for no less than 10 times in the isobutylene hydroformylation reaction, preferably can be recycled for up to 30 times.

[0033] According to a most preferred embodiment of the present invention, the active center of the catalyst is derived from hexadecyl hexarhodium, and the ligand is derived from tris(2,4-di-tert-butylphenyl)phosphite; wherein the molar ratio of the element P derived from the ligand to the element Rh derived from the active center is (5-8): 1. The catalyst of this preferred embodiment has further improved long-term operation stability in the isobutylene hydroformylation reaction.

[0034] According to the present invention, the catalyst can be prepared by mixing hexadecyl hexarhodium and phosphite ligand in the above ratio and in situ complexing.

[0035] The second aspect of the present invention provides a method for preparing isovaleraldehyde, comprising: in the presence of a catalyst and a solvent, subjecting isobutylene to a hydroformylation reaction with synthesis gas to obtain isovaleraldehyde;

[0036] Wherein, the catalyst is the catalyst described in the first aspect above.

[0037] According to the present invention, in the method for preparing isovaleraldehyde, preferably, in the liquid phase reaction system of the hydroformylation reaction, the concentration of the element Rh from the catalyst is 50-500 mg / L, which can better exert the catalytic effect of the catalyst and will not cause self-polymerization, which is conducive to subsequent application.

[0038] Preferably, in the reaction system of the hydroformylation reaction, the concentration of element Rh from the catalyst is 100-400 mg / L.

[0039] According to the present invention, in the method for preparing isovaleraldehyde, the solvent is an aldehyde, for example, can be selected from at least one of isovaleraldehyde, hexanal, heptaldehyde and heptanedial. From the perspective of use cost, separation energy consumption and separation efficiency, the solvent is preferably isovaleraldehyde.

[0040] In some embodiments of the present invention, in the method for preparing isovaleraldehyde, preferably, the temperature of the hydroformylation reaction is 60-120°C, which is conducive to obtaining a higher reaction conversion rate and product selectivity, and the reaction at a relatively low temperature can reduce the damage to the product and the occurrence of side reactions. Further preferably, the temperature of the hydroformylation reaction is 80-110°C.

[0041] In some embodiments of the present invention, in the method for preparing isovaleraldehyde, preferably, the hydroformylation reaction time is 4-12 hours.

[0042] In some embodiments of the present invention, in the method for preparing isovaleraldehyde, preferably, the pressure of the hydroformylation reaction is 1-5 MPa, which is conducive to obtaining a higher reaction conversion rate and product selectivity, and the reaction at a relatively low pressure can reduce damage to the catalyst and the occurrence of side reactions.

[0043] Further preferably, the pressure of the hydroformylation reaction is 2-4 MPa.

[0044] According to the present invention, in the method for preparing isovaleraldehyde, the synthesis gas contains carbon monoxide and hydrogen. Preferably, in the synthesis gas, the volume ratio of carbon monoxide to hydrogen is 1:1-2.

[0045] In the present invention, the hydroformylation reaction may adopt the conventional reaction operation mode of the hydroformylation reaction of isobutylene and synthesis gas in the presence of a catalyst and a solvent in the art, and the present invention has no particular limitation on this.

[0046] The method for preparing isovaleraldehyde provided by the present invention uses isobutylene and synthesis gas as raw materials, preferably uses isovaleraldehyde as solvent, and uses the catalyst provided by the present invention to catalyze a hydroformylation reaction, which can achieve an isobutylene conversion rate of more than 97% and an isovaleraldehyde selectivity of more than 97% in the first reaction, and the catalyst can operate stably for a long time during the reaction process. After the reaction, the product is separated by distillation, and the high-boiling liquid containing the catalyst is directly recycled back to the reaction system to continue the catalytic reaction, and the cycle can be applied for no less than 10 times, preferably up to 30 times.

[0047] In the present invention, the catalyst is used repeatedly in the above-mentioned reaction for preparing isovaleraldehyde. When the isobutylene conversion rate is lower than 95%, it is considered that the catalyst cannot meet the use requirements (ie, it cannot be used further).

[0048] The present invention will be described in detail below by way of examples. In the following preparation examples and embodiments, unless otherwise specified, all materials used are common commercially available products.

[0049] Preparation of hexadecyl hexarhodium: Under nitrogen protection, 3.41g of silicon dioxide, 0.5g of hydrated rhodium trichloride (containing Rh1.91mmol) and 3.2g of sodium acetate (39mmol) were added to 100mL of water, stirred at 20-25°C for 10h, and water was evaporated under reduced pressure at 60°C to obtain a powder solid; the above powder solid was put into a high-pressure reactor, evacuated and then flushed with carbon monoxide at a pressure of 3.0MPa, stirred at 60°C for 48h, cooled to 25°C, extracted four times with 600mL of dichloromethane, combined the extracts, and evaporated to remove dichloromethane to obtain 0.31g hexadecyl hexarhodium (containing Rh 1.74mmol), with a yield of 91%.

[0050] Example 1

[0051] 30 mL of isovaleraldehyde, 5.2 mg of hexadecyl hexarhodium carbonyl (containing 0.029 mmol of Rh), and 45.3 mg of triphenyl phosphite (0.146 mmol) were added to a 100 mL high-pressure reactor with magnetically driven stirring to form a reaction system, wherein the Rh concentration in the reaction system was 100 mg / L, and the molar ratio of P to Rh in the catalyst (hexadecyl hexarhodium carbonyl complexed with triphenyl phosphite, denoted as C1) was 5.03:1;

[0052] The system was replaced with nitrogen three times, and then replaced once with a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1, and then 11.2 g (0.2 mol) of isobutylene was introduced, and then about 1 MPa of the mixed gas of carbon monoxide and hydrogen was charged, stirring was started, the temperature was raised to 80°C, and the mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1 was continued to be charged until the reaction pressure reached 2 MPa, the reaction was started and timing was started, and the reaction was completed after 6 hours;

[0053] The reaction system was cooled to room temperature and samples were taken for testing. The conversion rate of isobutylene was 99.1% and the selectivity of isovaleraldehyde was 97.2%.

[0054] After isovaleraldehyde was distilled out of the product system under reduced pressure, the high boiling liquid containing catalyst C1 was recycled back to the above reaction system for application. After the catalyst was applied 18 times, the conversion rate of isobutylene still reached 98.5%, and the selectivity of isovaleraldehyde reached 97.0%.

[0055] Example 2

[0056] 30 mL of isovaleraldehyde, 5.2 mg of hexadecyl hexarhodium (containing 0.029 mmol of Rh), and 94.5 mg of tris(2,4-di-tert-butylphenyl) phosphite (0.146 mmol) were added to a 100 mL high-pressure reactor with magnetically driven stirring to form a reaction system, wherein the Rh concentration in the reaction system was 100 mg / L, and the molar ratio of P to Rh in the catalyst (hexadecyl hexarhodium and tris(2,4-di-tert-butylphenyl) phosphite complexed to form a catalyst, denoted as C2) was 5.05:1;

[0057] The system was replaced with nitrogen three times, and then replaced once with a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1, and then 11.2 g (0.2 mol) of isobutylene was introduced, and then about 1 MPa of the mixed gas of carbon monoxide and hydrogen was charged, stirring was started, the temperature was raised to 80°C, and the mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1 was continued to be charged until the reaction pressure reached 2 MPa, the reaction was started and timing was started, and the reaction was completed after 6 hours;

[0058] The reaction system was cooled to room temperature and samples were taken for testing. The conversion rate of isobutylene was 99.5% and the selectivity of isovaleraldehyde was 98.3%.

[0059] After isovaleraldehyde is distilled off under reduced pressure in the product system, the high boiling liquid containing catalyst C2 is recycled back to the above reaction system for application. After the catalyst is applied 30 times, the conversion rate of isobutylene still reaches 99.0%, and the selectivity of isovaleraldehyde reaches 98.0%.

[0060] Example 3

[0061] In a 100 mL autoclave with magnetically driven stirring, 30 mL of isovaleraldehyde, 5.2 mg of hexadecyl hexarhodium (containing 0.029 mmol Rh), 116.3 mg of 6,6'-[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[D,F][1,3,2]dioxaphosphine) (0.148 mmol) was added to form a reaction system, wherein the Rh concentration in the reaction system was 100 mg / L, and the molar ratio of P to Rh in the catalyst (hexadecyl hexarhodium and 6,6'-[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[D,F][1,3,2]dioxaphosphine) was 5.1:1;

[0062] The system was replaced with nitrogen three times, and then replaced once with a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1, and then 11.2 g (0.2 mol) of isobutylene was introduced, and then about 1 MPa of the above-mentioned mixed gas of carbon monoxide and hydrogen was charged, stirring was started, the temperature was raised to 80°C, and then a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1 was charged to a reaction pressure of 2 MPa, the reaction was started and timing was started, and the reaction was completed after 6 hours;

[0063] The reaction system was cooled to room temperature and samples were taken for testing. The conversion rate of isobutylene was 97.3% and the selectivity of isovaleraldehyde was 98.2%.

[0064] After isovaleraldehyde is distilled off under reduced pressure in the product system, the high boiling liquid containing catalyst C3 is recycled back to the above reaction system for application. After the catalyst is applied 15 times, the conversion rate of isobutylene still reaches 96.8%, and the selectivity of isovaleraldehyde reaches 97.0%.

[0065] Example 4

[0066] 30 mL of isovaleraldehyde, 5.2 mg of hexadecyl hexarhodium (containing 0.029 mmol of Rh), and 150.1 mg of tris(2,4-di-tert-butylphenyl) phosphite (0.232 mmol) were added to a 100 mL high pressure reactor with magnetically driven stirring to form a reaction system, wherein the Rh concentration in the reaction system was 100 mg / L, and the molar ratio of P to Rh in the catalyst (hexadecyl hexarhodium and tris(2,4-di-tert-butylphenyl) phosphite complexed to form a catalyst, denoted as C4) was 8.0:1;

[0067] The system was replaced with nitrogen three times, and then replaced once with a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1, and then 11.2 g (0.2 mol) of isobutylene was introduced, and then about 1 MPa of the above-mentioned mixed gas of carbon monoxide and hydrogen was charged, stirring was started, the temperature was raised to 80°C, and then a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1 was charged to a reaction pressure of 2 MPa, the reaction was started and timing was started, and the reaction was completed after 6 hours;

[0068] The reaction system was cooled to room temperature and samples were taken for testing. The conversion rate of isobutylene was 98.5%, and the selectivity of isovaleraldehyde was 98.4%.

[0069] After isovaleraldehyde is distilled off under reduced pressure in the product system, the high boiling liquid containing catalyst C4 is recycled back to the above reaction system for application. After the catalyst is applied 13 times, the conversion rate of isobutylene still reaches 97.8%, and the selectivity of isovaleraldehyde reaches 98.0%.

[0070] Example 5

[0071] 30 mL of isovaleraldehyde, 15.5 mg of hexadecyl hexarhodium carbonyl (containing 0.088 mmol of Rh), and 252.8 mg of tris(2-tert-butyl-4-methylphenyl)phosphite (0.440 mmol) were added to a 100 mL high pressure reactor with magnetically driven stirring to form a reaction system, wherein the Rh concentration in the reaction system was 300 mg / L, and the molar ratio of P to Rh in the catalyst (hexadecyl hexarhodium carbonyl complexed with tris(2,4-xylyl)phosphite, denoted as C5) was 5.0:1;

[0072] The system was replaced with nitrogen three times, and then replaced once with a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1, and then 11.2 g (0.2 mol) of isobutylene was introduced, and then about 1 MPa of the above-mentioned mixed gas of carbon monoxide and hydrogen was charged, stirring was started, the temperature was raised to 80°C, and then a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1 was charged to a reaction pressure of 2 MPa, the reaction was started and timing was started, and the reaction was completed after 6 hours;

[0073] The reaction system was cooled to room temperature and samples were taken for testing. The conversion rate of isobutylene was 99.6% and the selectivity of isovaleraldehyde was 98.2%.

[0074] After isovaleraldehyde is distilled off under reduced pressure in the product system, the high boiling liquid containing catalyst C5 is recycled back to the above reaction system for application. After the catalyst is applied 14 times, the conversion rate of isobutylene still reaches 99.1%, and the selectivity of isovaleraldehyde reaches 98.0%.

[0075] Example 6

[0076] 30 mL of isovaleraldehyde, 5.2 mg of hexadecyl hexarhodium (containing 0.029 mmol of Rh), and 175.4 mg of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite (0.29 mmol) were added to a 100 mL high pressure reactor with magnetically driven stirring to form a reaction system, wherein the Rh concentration in the reaction system was 300 mg / L, and the molar ratio of P to Rh in the catalyst (hexadecyl hexarhodium and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite complexed to form a catalyst, denoted as C2) was 10:1;

[0077] The system was replaced with nitrogen three times, and then replaced once with a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1, and then 11.2 g (0.2 mol) of isobutylene was introduced, and then about 1 MPa of the mixed gas of carbon monoxide and hydrogen was charged, stirring was started, the temperature was raised to 80°C, and the mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1 was continued to be charged until the reaction pressure reached 2 MPa, the reaction was started and timing was started, and the reaction was completed after 6 hours;

[0078] The reaction system was cooled to room temperature and samples were taken for testing. The conversion rate of isobutylene was 98.1% and the selectivity of isovaleraldehyde was 98.0%.

[0079] After isovaleraldehyde was distilled off under reduced pressure in the product system, the high boiling liquid containing catalyst C2 was recycled back to the above reaction system for application. After the catalyst was applied 11 times, the conversion rate of isobutylene still reached 97.1%, and the selectivity of isovaleraldehyde reached 97.2%.

[0080] Comparative Example 1

[0081] 30 mL of isovaleraldehyde, 7.5 mg of acetylacetonato dicarbonyl rhodium (containing 0.029 mmol of Rh), and 150.1 mg of tris(2,4-di-tert-butylphenyl) phosphite (0.232 mmol) were added to a 100 mL high-pressure reactor with magnetically driven stirring to form a reaction system, wherein the Rh concentration in the reaction system was 100 mg / L, and the molar ratio of P to Rh in the catalyst (a catalyst formed by complexation of acetylacetonato dicarbonyl rhodium and tris(2,4-di-tert-butylphenyl) phosphite, denoted as DC1) was 8.0:1;

[0082] The system was replaced with nitrogen three times, and then replaced once with a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1, and then 11.2 g (0.2 mol) of isobutylene was introduced, and then about 1 MPa of the above-mentioned mixed gas of carbon monoxide and hydrogen was charged, stirring was started, the temperature was raised to 80°C, and then a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1 was charged to a reaction pressure of 2 MPa, the reaction was started and timing was started, and the reaction was completed after 6 hours;

[0083] The reaction system was cooled to room temperature and samples were taken for testing. The conversion rate of isobutylene was 97.0% and the selectivity of isovaleraldehyde was 98.4%.

[0084] After isovaleraldehyde was distilled off under reduced pressure in the product system, the high boiling liquid containing catalyst DC1 was recycled back to the above reaction system for application. After the catalyst was applied 7 times, the conversion rate of isobutylene dropped to 90%, and the selectivity of isovaleraldehyde was 96%.

[0085] Comparative Example 2

[0086] 30 mL of isovaleraldehyde, 26.8 mg of tris(triphenylphosphine)carbonyl rhodium hydride (containing 0.029 mmol of Rh), and 150.1 mg of tris(2,4-di-tert-butylphenyl) phosphite (0.232 mmol) were added to a 100 mL high-pressure reactor with magnetically driven stirring to form a reaction system, wherein the Rh concentration in the reaction system was 100 mg / L, and the molar ratio of P to Rh in the catalyst (tris(triphenylphosphine)carbonyl rhodium hydride and tris(2,4-di-tert-butylphenyl) phosphite complexed to form a catalyst, denoted as DC2) was 8.0:1;

[0087] The system was replaced with nitrogen three times, and then replaced once with a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1, and then 11.2 g (0.2 mol) of isobutylene was introduced, and then about 1 MPa of the above-mentioned mixed gas of carbon monoxide and hydrogen was charged, stirring was started, the temperature was raised to 80°C, and then a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1 was charged to a reaction pressure of 2 MPa, the reaction was started and timing was started, and the reaction was completed after 6 hours;

[0088] The reaction system was cooled to room temperature, and samples were taken for testing. The conversion rate of isobutylene was 97.0%, and the selectivity of isovaleraldehyde was 95.0%.

[0089] After isovaleraldehyde was distilled off under reduced pressure in the product system, the high boiling liquid containing catalyst DC2 was recycled back to the above reaction system for application. After the catalyst was applied 4 times, the conversion rate of isobutylene dropped to 84% and the selectivity of isovaleraldehyde was 91%.

[0090] Comparative Example 3

[0091] In a 100 mL autoclave with magnetically driven stirring, 30 mL of isovaleraldehyde, 5.2 mg of hexadecyl hexarhodium (containing 0.029 mmol Rh), 47.4 mg of 6,6'-[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[D,F][1,3,2]dioxaphosphine heteroheptyl (0.058 mmol) was added to form a reaction system, wherein the Rh concentration in the reaction system was 100 mg / L, and the molar ratio of P to Rh in the catalyst (hexadecyl hexarhodium and 6,6'-[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[D,F][1,3,2]dioxaphosphine heteroheptyl to form a catalyst, denoted as DC3) was 2:1;

[0092] The system was replaced with nitrogen three times, and then replaced once with a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1, and then 11.2 g (0.2 mol) of isobutylene was introduced, and then about 1 MPa of the above-mentioned mixed gas of carbon monoxide and hydrogen was charged, stirring was started, the temperature was raised to 80°C, and then a mixed gas of carbon monoxide and hydrogen in a volume ratio of 1:1 was charged to a reaction pressure of 2 MPa, the reaction was started and timing was started, and the reaction was completed after 6 hours;

[0093] The reaction system was cooled to room temperature, and samples were taken for testing. The conversion rate of isobutylene was 94.0%, and the selectivity of isovaleraldehyde was 95.0%.

[0094] After isovaleraldehyde was distilled off under reduced pressure in the product system, the high boiling liquid containing catalyst DC3 was recycled back to the above reaction system for application. After the catalyst was applied 5 times, the conversion rate of isobutylene was 85% and the selectivity of isovaleraldehyde was 93%.

[0095] It can be seen from the above embodiments and comparative examples that the catalyst provided by the present invention can achieve efficient and highly selective hydroformylation of isobutylene, with an isobutylene conversion rate of >97% and an isovaleraldehyde selectivity of >97% in the first reaction, and can be recycled for no less than 10 times, preferably up to 30 times, and has excellent long-term operation stability.

[0096] 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 catalyst for olefin hydroformylation reaction, characterized in that: The catalyst is a coordination compound, comprising an active center and a ligand; wherein the active center is derived from hexadecyl hexarhodium, and the ligand is derived from phosphite; In the catalyst, the molar ratio of element P:element Rh is (4-10):

1.

2. The catalyst according to claim 1, wherein In the catalyst, the molar ratio of element P:element Rh is (5-8):

1.

3. The catalyst according to claim 1 or 2, wherein The phosphite is selected from monophosphites and / or bisphosphites.

4. The catalyst according to claim 3, wherein The monophosphite is selected from triphenyl phosphite, tri(2-tert-butyl-4-methylphenyl)phosphite and tri(2,4-di-tert-butylphenyl)phosphite, preferably at least one of tri(2,4-di-tert-butylphenyl)phosphite; And / or, the bisphosphite is selected from 6,6'-[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[D,F][1,3,2]dioxaphosphinyl) and / or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, preferably 6,6'-[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[D,F][1,3,2]dioxaphosphinyl) 5. A method for preparing isovaleraldehyde, characterized in that: include: In the presence of a catalyst and a solvent, isobutylene is subjected to a hydroformylation reaction with synthesis gas to obtain isovaleraldehyde; Wherein, the catalyst is the catalyst described in any one of claims 1-4.

6. The method according to claim 5, wherein: In the liquid phase reaction system of the hydroformylation reaction, the concentration of element Rh from the catalyst is 50-500 mg / L, preferably 100-400 mg / L.

7. The method according to claim 5 or 6, wherein: The solvent is an aldehyde, preferably at least one of isovaleraldehyde, hexanal, heptaldehyde and heptanedial.

8. The method according to any one of claims 5 to 7, wherein: The temperature of the hydroformylation reaction is 60-120°C, preferably 80-110°C; And / or, the hydroformylation reaction time is 4-12 hours.

9. The method according to any one of claims 5 to 8, wherein: The pressure of the hydroformylation reaction is 1-5 MPa, preferably 2-4 MPa.

10. The method according to any one of claims 5 to 9, wherein: The synthesis gas contains carbon monoxide and hydrogen; Preferably, in the synthesis gas, the volume ratio of carbon monoxide to hydrogen is 1:1-2.