Catalyst composition of bidentate phosphorus ligand as well as preparation method and application of catalyst composition

Abstract

The present invention relates to a bidentate phosphorus ligand catalyst composition and a preparation method and application thereof, the catalyst composition comprises a bidentate phosphorus ligand, a nickel catalyst and at least one Lewis acid accelerator, the bidentate phosphorus ligand has a 3, 3-bis (methoxy)-5, 5-dimethyl-2, 2-bisphenol structural skeleton, and the nickel catalyst has at least one Lewis acid accelerator, and the at least one Lewis acid accelerator has a 3, 3-bis (methoxy)-5, 5-dimethyl-2, 2-bisphenol structural skeleton and a 3, 3-bis (methoxy)-5, 5-dimethyl-2, 2-bisphenol structural skeleton. Hydrogen of hydroxyl is respectively substituted by monophosphine and mononite to form a chelating structure. The catalyst composition can be prepared by mixing a bivalent nickel compound and a ligand in an inert atmosphere to form a complex, then adding a reducing agent for reduction to obtain a zero-valent nickel catalyst. The catalyst composition can be used for catalyzing the hydrocyanation reaction of olefin, and is especially suitable for the reaction of 3-pentenenitrile and hydrocyanic acid to prepare an adiponitrile product with high added value. The catalyst system provided by the invention has high reaction activity and selectivity and good catalyst stability, is suitable for an industrial continuous reaction process, and significantly improves the production efficiency of adiponitrile and reduces the use cost of the catalyst.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical synthesis, and more particularly, to a catalyst composition of a bidentate phosphorus ligand, a preparation method thereof, and an application thereof. Background Art

[0002] Phosphorus ligands have extensive application values in catalytic chemistry and have been widely used in many industrially important transformation reactions. Common phosphorus ligands include monophosphine (A) and monophosphonate (B) ligands, and their typical structures are shown in the following formula, where the R group can be various different organic substituents. Monophosphine and monophosphonate ligands are compounds containing a single phosphorus donor atom, which can form coordination bonds with metal centers, thereby constructing catalytic active centers. In contrast, bidentate phosphine, bisphosphonate or other bidentate phosphorus ligand structures have two phosphorus donor atoms and are often used to form stable cyclic chelate complexes with transition metals, enhancing their stability and electron regulation ability in the catalytic system.

[0003]

[0004] There have been many important industrial catalytic reactions using phosphorus ligands to participate in the construction of homogeneous metal catalyst systems. These catalytic processes include hydrogenation, hydroformylation, hydrocyanation, hydrocarboxylation, hydroamidation, hydroesterification, and aldol condensation, covering many important application scenarios from basic organic synthesis to the preparation of polymer monomers.

[0005] In specific industrial applications, for example, the production of adiponitrile (ADN) through the hydrocyanation reaction of 3-pentanenitrile, which is a key intermediate for manufacturing nylon 66, has extremely high market demand. Given the strategic position of adiponitrile in the polyamide industry, even a slight improvement in the reaction rate, selectivity, or stability of the catalytic system will bring significant commercial value and process advantages. Therefore, continuously developing new ligands and catalyst systems with wide applicability and higher efficiency for such reaction systems is a research focus in the catalytic field.

[0006] Although the current phosphorus ligand-metal catalyst system has achieved certain results in industry, there are still the following technical bottlenecks and optimization spaces: Some traditional phosphorus ligand structures have insufficient rigidity and limited electron property regulation, making it difficult to fully regulate the reaction activity of metal centers; In an environment of high reaction temperature, high concentration of hydrocyanic acid, or low water content, the existing catalyst system may have problems such as activity decline, side reaction generation, or ligand dissociation; In the construction of the current catalyst composition, the synergistic effect between the phosphorus ligand and the metal source has not been fully explored, and there is still room for improvement in the overall selectivity and turnover frequency (TOF) of the catalyst; The types, dosages of the Lewis acid promoters and their synergistic mechanisms with the metal centers lack systematic optimization, which limits the stability and industrial applicability of the catalytic system.

[0007] Therefore, there is an urgent need to develop a novel bidentate phosphorus ligand with more structural advantages, which can stably coordinate with transition metals (such as nickel) and exhibit more excellent catalytic performance in various important reactions including hydrocyanation. At the same time, the new catalyst composition should have good stability, selectivity and controllability to meet the requirements of efficient, safe and sustainable processes in industrial applications. Summary of the Invention

[0008] The first technical problem to be solved by the present invention is to provide a catalyst composition of a bidentate phosphorus ligand to solve the problems of insufficient catalyst activity, poor reaction selectivity and poor reusability of the catalyst in the prior art.

[0009] To overcome the defects of the above prior art, the present invention provides a catalyst composition of a bidentate phosphorus ligand. The catalyst composition of the bidentate phosphorus ligand includes a bidentate phosphorus ligand, a nickel catalyst and at least one Lewis acid promoter, and the bidentate phosphorus ligand includes a skeleton having a 3,3,-bis(methoxy)-5,5-dimethyl-2,2-bisphenol structure, wherein the hydrogen atoms of the hydroxyl groups are respectively replaced by monophosphine and monophosphite ligand substituents.

[0010] Compared with the prior art, the catalyst composition of a bidentate phosphorus ligand in the present application has the following advantages: This catalyst composition can be used in a variety of important olefin hydrocyanation reactions, especially the hydrocyanation reaction of 3-pentenenitrile to prepare adiponitrile, with high catalytic activity and selectivity. Moreover, the catalyst composition of the present invention has significant advantages compared with the prior art: By using a bidentate phosphorus ligand with a specific structure, combined with a zero-valent nickel catalyst and a Lewis acid promoter, the stability and selectivity of the catalyst are effectively improved, especially for the efficient catalytic effect in the hydrocyanation reaction. The structure of the bidentate phosphorus ligand can effectively form a stable chelate complex with nickel metal, which helps to improve the reactivity of the catalyst and avoid the occurrence of side reactions; in addition, the synergistic effect of the Lewis acid promoter and nickel further enhances the efficiency and stability of the catalyst, enabling it to maintain high catalytic performance during a long reaction process. The catalyst composition of the present invention can achieve a hydrocyanation reaction with high selectivity and high yield under relatively mild reaction conditions. Compared with the common catalysts in the prior art, it can reduce the consumption of the catalyst and improve the economy of the reaction. At the same time, it can also achieve the efficient recovery and reuse of the catalyst, avoiding the problem of rapid deactivation of traditional catalysts, helping to reduce production costs, meeting the requirements of green chemistry and sustainable development, solving the problems of unstable catalyst performance, poor selectivity, and short service life in the prior art, improving the industrial application efficiency of related chemical reactions, and promoting the innovation and development of catalysts in related fields.

[0011] As a preferred embodiment, in the bidentate phosphorus ligand, the substituents of the monophosphine and monophosphite ligands are o-methylphenoxyphosphine P(OR1)2 and diphenylphosphine P(R2)2 respectively, where R1 is o-methylphenyl and R2 is phenyl.

[0012] As a preferred embodiment, the chemical formula of the bidentate phosphorus ligand is: 。

[0013] Compared with the prior art, adopting the above technical solution, with o-methylphenoxyphosphine and diphenylphosphine as the substituent groups of the ligand, stronger electronic effects can be provided, enabling better regulation of the electron cloud density of the nickel center. The electronic effect of the o-methylphenyl group can enhance the chelating ability of the ligand with the nickel metal, thereby optimizing the electronic structure of the nickel metal and making it more suitable for participating in catalytic reactions. In the present invention, the diphenylphosphine group improves the stability of the ligand and the selectivity of the catalyst through the combination of steric effects and electronic effects, thereby reducing the occurrence of side reactions. By selecting a specific bidentate phosphorus ligand, the present invention can reduce the generation of by-products while improving the catalytic activity, and improve the selectivity and efficiency of the reaction. This enables the catalyst to exhibit higher stability and longer service life in a wider range of industrial reactions, especially in key reactions such as hydrocyanation. The catalyst of the present invention can achieve higher production efficiency, reduce reaction costs, and better meet the stringent requirements for catalyst performance in industrial production.

[0014] As a preferred embodiment, the nickel catalyst is a zero-valent nickel catalyst or a mixture of a divalent nickel catalyst and a reducing agent.

[0015] Compared with the prior art, adopting the above technical solution, using a mixture of zero-valent nickel and a divalent nickel compound, combined with a reducing agent, can effectively control the valence state of nickel under a suitable reducing environment, further improving its catalytic activity. The zero-valent nickel catalyst can directly participate in the catalysis during the reaction process, while the divalent nickel catalyst can be converted into zero-valent nickel or other active forms when necessary after reacting with the reducing agent, further enhancing the catalytic effect. By controlling the appropriate reducing agent, over-reduction or oxidation of the nickel catalyst can be effectively avoided, maintaining the optimal active state of the catalyst.

[0016] As a preferred embodiment, the divalent nickel catalyst is a compound with the molecular formula NiY2, where Y is a halide, carboxylate, or acetylacetonate; the reducing agent is one of metal borohydrides, metal aluminum hydrides, metal alkyls, Zn, Fe, Al, Na, and H2.

[0017] Compared with the prior art, adopting the above technical solution, the divalent nickel catalyst (such as NiY2) has strong reactivity and can be reduced to zero-valent nickel under the action of a suitable reducing agent to participate in the catalytic reaction. By selecting halides, carboxylates, or acetylacetonates as ligands, the stability of nickel can be enhanced, avoiding the inactivation of the catalyst during the reaction process. Reducing agents such as metal borohydrides and metal aluminum hydrides can efficiently reduce divalent nickel to zero-valent nickel while increasing the rate and selectivity of the catalytic reaction. As a preferred embodiment, the Lewis acid promoter is an inorganic or organometallic compound, and at least one element in the inorganic or organometallic compound is selected from scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium, zirconium, niobium, and molybdenum.

[0018] Compared with the prior art, by adopting the above technical solution, using an inorganic or organometallic compound as the Lewis acid promoter can be finely adjusted according to the requirements of different reaction systems and catalysts. In particular, elements such as scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium, zirconium, niobium, and molybdenum are selected. These elements can effectively cooperate with the nickel catalyst, improve the electronic environment of the catalyst, enhance the interaction between the catalyst and the reactants, thereby increasing the rate and selectivity of the catalytic reaction. The catalytic system using the above Lewis acid promoter can significantly improve the selectivity, rate, and stability of the catalyst. In some special reactions (including olefin hydrocyanation reaction, hydrogenation reaction, etc.), these Lewis acid promoters can better control the reaction path, reduce the formation of by-products, and increase the yield and purity of the target product.

[0019] As a preferred embodiment, the Lewis acid promoter is one of ZnBr2, ZnI2, ZnCl2, ZnSO4, CuCl, CuCl2, FeI, FeCl3, FeCl2, TiCl4, TiCl3, MnCl2, AlCl3, ZrCl4, or NbCl2, and the molar ratio of the Lewis acid promoter to nickel is (1 - 50):(16 - 1).

[0020] Compared with the prior art, by adopting the above technical solution, the Lewis acid promoter activates the catalyst surface and provides additional reaction sites through the coordination of its metal center with the reactants, which can effectively improve the selectivity of the catalytic reaction and avoid the formation of by-products. For example, selecting strong Lewis acids such as ZnCl2 and AlCl3 can increase the electron density of nickel in the catalytic reaction, enabling nickel to interact more effectively with the reactants and increase the reaction rate. Moreover, through the reasonable molar ratio of the Lewis acid promoter to the nickel catalyst in the above technical solution of the present invention (from 1:16 to 1:50), the catalytic performance of the catalyst can be precisely controlled, significantly increasing the rate and selectivity of the reaction, thereby optimizing the production process. Especially in key chemical reactions such as olefin hydrocyanation reaction and hydrogenation reaction, the yield of the product can be significantly increased and the formation of by-products can be reduced. In addition, since this technical solution can reduce the deactivation rate of the catalyst and extend the service life of the catalyst, it helps to reduce the cost in the long-term production process, while improving the economy and environmental friendliness of the process.

[0021] The second technical problem to be solved by the present invention is to provide a method for preparing a catalyst composition of the bidentate phosphorus ligand, so as to solve the problems of complex catalyst preparation process, cumbersome steps and low efficiency in the prior art.

[0022] To overcome the above defects of the prior art, the present invention provides a method for preparing a catalyst composition of the bidentate phosphorus ligand, comprising the following steps: S1: Under the protection of an inert gas, a divalent nickel compound, a bidentate phosphorus ligand and a reaction medium are mixed, and heated and stirred to form a chelating complex system; S2: After cooling the mixed system, a reducing agent is added for a reduction reaction, and continuously stirred to form a catalyst composition containing zero-valent nickel; S3: Solid impurities are removed by filtration to obtain the catalyst composition of the bidentate phosphorus ligand.

[0023] Compared with the prior art, the method for preparing a catalyst composition of a bidentate phosphorus ligand in the present application has the following advantages: First, the reaction process under the protection of an inert gas can effectively avoid the oxidation reaction of the divalent nickel compound, thereby maintaining the high efficiency of the reaction and the stability of the catalyst; Second, the reduction reaction using a reducing agent can efficiently convert divalent nickel into active zero-valent nickel, reducing unnecessary side reactions in the synthesis process of the catalyst; Finally, removing solid impurities by filtration in step S3 can further improve the purity of the catalyst, ensuring high activity and high selectivity of the catalyst; The preparation method of the present invention simplifies the reaction steps, reduces the production cost, improves the synthesis efficiency of the catalyst and the purity of the product compared with the complex synthesis route in the prior art. In addition, due to the simple reaction process and mild reaction conditions used, energy consumption can be reduced and the long-term stability of the catalyst can be improved. Therefore, the present invention can better solve the problems of low catalyst synthesis efficiency, cumbersome steps and high cost mentioned in the background art, and has significant technical advantages.

[0024] The third technical problem to be solved by the present invention is to provide an application of the catalyst composition of the bidentate phosphorus ligand, so as to solve the problems of low catalyst activity, poor selectivity in the hydrocyanation reaction and difficult catalyst recovery in the prior art.

[0025] To overcome the above defects of the prior art, the present invention provides an application of the catalyst composition of the bidentate phosphorus ligand, and the application includes using the catalyst composition of the bidentate phosphorus ligand in the preparation of adiponitrile, comprising the following steps: A1: Mix the catalyst composition of the bidentate phosphorus ligand with an olefin and a cyanide source in a suitable solvent, and maintain appropriate temperature and pressure conditions in the reaction system; A2: Carry out the hydrocyanation reaction for 1 to 10 hours at a reaction temperature of 50°C to 120°C to obtain the adiponitrile product; A3: Carry out vacuum distillation on the reaction mixture to separate and recover unreacted hydrocyanic acid, 3-pentenenitrile, the product adiponitrile and by-products, and recover the catalyst system by extraction.

[0026] As a preferred solution, the application includes the following steps: A1: Mix the catalyst composition of the bidentate phosphorus ligand with 3-pentenenitrile and a cyanide source in a reactor, the cyanide source being hydrocyanic acid or its precursor cyanohydrin, and the water content of the hydrocyanic acid being less than 250 ppm; A2: Carry out the hydrocyanation reaction in a temperature range of 25 - 150°C and a pressure range of 1.03 - 20.7 bar, with the molar ratio of hydrocyanic acid to 3-pentenenitrile being (1 - 10):1 and the molar ratio of hydrocyanic acid to the catalyst composition of the bidentate phosphorus ligand being (300 - 2000):1; A3: After the reaction is completed, carry out vacuum distillation on the reaction solution obtained in step A2 to separate and recover the adiponitrile product and unreacted components, and at the same time use an extractant to recover the catalyst components to achieve catalytic recycling.

[0027] Compared with the prior art, the application of the catalyst composition of the bidentate phosphorus ligand in this application has the following advantages: First, by using a catalytic system combining a bidentate phosphorus ligand and a nickel catalyst, the activity and selectivity of the hydrocyanation reaction can be effectively improved, and the yield of adiponitrile can be increased; Second, by adjusting the molar ratio of hydrocyanic acid to 3-pentenenitrile and temperature and pressure conditions, an efficient hydrocyanation reaction can be achieved in a short time while reducing the generation of by-products; Finally, by recovering the catalyst system through vacuum distillation and extraction methods, the recycling of the catalyst is realized, the loss of the catalyst is reduced, and the economic benefits are improved. The application of the present invention directly solves the problems of low efficiency of the hydrocyanation reaction and difficult catalyst recovery in the prior art, and further improves the use efficiency and reaction selectivity of the catalyst. By optimizing the reaction conditions and the use of the catalyst, the yield and purity of adiponitrile are significantly improved, meeting the requirements of industrial production. Detailed implementation modes

[0028] First of all, those skilled in the art should understand that these implementation modes are only used to explain the technical principles of the embodiments of this application, and are not intended to limit the protection scope of the embodiments of this application. Those skilled in the art can make adjustments according to needs to adapt to specific application scenarios.

[0029] The present invention provides a catalyst composition of a bidentate phosphorus ligand, which includes a bidentate phosphorus ligand, a nickel catalyst, and at least one Lewis acid promoter. The bidentate phosphorus ligand includes a skeleton with a 3,3'-bis(methoxy)-5,5'-dimethyl-2,2'-biphenol structure, where the hydrogen atoms of the hydroxyl groups are respectively substituted by a monophosphine and a monophosphite ligand substituent group.

[0030] As a preferred embodiment, in the bidentate phosphorus ligand, the monophosphine and the monophosphite ligand substituent groups are respectively o-methylphenoxyphosphine P(OR1)2 and diphenylphosphine P(R2)2, where R1 is o-methylphenyl and R2 is phenyl.

[0031] As a preferred embodiment, the chemical formula of the bidentate phosphorus ligand is: 。

[0032] As a preferred embodiment, the nickel catalyst is a zero-valent nickel catalyst or a mixture of a divalent nickel compound and a reducing agent.

[0033] As a preferred embodiment, the divalent nickel compound is a compound with the molecular formula NiY2, where Y is a halide, a carboxylate, or an acetylacetonate; the reducing agent is one of metal borohydrides, metal aluminum hydrides, metal alkyls, Zn, Fe, Al, Na, and H2.

[0034] As a preferred embodiment, the Lewis acid promoter is an inorganic or organometallic compound, and at least one element in the inorganic or organometallic compound is selected from scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium, zirconium, niobium, and molybdenum.

[0035] As a preferred embodiment, the Lewis acid promoter is one of ZnBr2, ZnI2, ZnCl2, ZnSO4, CuCl, CuCl2, FeI, FeCl3, FeCl2, TiCl4, TiCl3, MnCl2, AlCl3, ZrCl4, or NbCl2, and the molar ratio of the Lewis acid promoter to nickel is (1 - 50):(16 - 1).

[0036] The present invention also provides a preparation method of the catalyst composition of the bidentate phosphorus ligand, including the following steps: S1: Under the protection of an inert gas, mix a divalent nickel compound with the bidentate phosphorus ligand and a reaction medium, and heat and stir to form a chelating complex system; S2: After cooling the mixed system, add a reducing agent for a reduction reaction, and continuously stir to form a catalyst composition containing zero-valent nickel; S3: Filter to remove solid impurities to obtain the catalyst composition of the bidentate phosphorus ligand.

[0037] The present invention also provides an application of the catalyst composition of the bidentate phosphorus ligand, and the application includes using the catalyst composition of the bidentate phosphorus ligand in the preparation of adiponitrile, including the following steps: A1: Mix the catalyst composition of the bidentate phosphorus ligand with an olefin and a cyanide source in a suitable solvent, and maintain appropriate temperature and pressure conditions in the reaction system; A2: Carry out hydrocyanation reaction, the reaction time is 1 to 10 hours, and the reaction temperature is 50°C to 120°C to obtain the adiponitrile product; A3: Carry out vacuum distillation on the reaction mixture to separate and recover unreacted hydrocyanic acid, 3-pentenenitrile, the product adiponitrile and by-products, and recover the catalyst system by extraction.

[0038] As a preferred scheme, the application includes the following steps: A1: Mix the catalyst composition of the bidentate phosphorus ligand with 3-pentenenitrile and a cyanide source in a reactor, the cyanide source is hydrocyanic acid or its precursor cyanohydrin, and the water content of the hydrocyanic acid is less than 250 ppm; A2: Carry out hydrocyanation reaction in the temperature range of 25 - 150°C and the pressure range of 1.03 - 20.7 bar, the molar ratio of hydrocyanic acid to 3-pentenenitrile is (1 - 10):1, and the molar ratio of hydrocyanic acid to the catalyst composition of the bidentate phosphorus ligand is (300 - 2000):1; A3: After the reaction is completed, carry out vacuum distillation treatment on the reaction solution obtained in step A2 to separate and recover the adiponitrile product and unreacted components, and at the same time use an extractant to recover the catalyst component to realize catalytic recycling.

[0039] More specifically, using the method of the present invention, bidentate phosphorus ligand A can be successfully prepared by reacting 3,3,-bis(methoxy)-5,5-dimethyl-2,2-bisphenol with a phosphite of the formula (R1O)2PCL or diphenylphosphine chloride.

[0040] The catalyst composition disclosed in the present invention comprises the novel bidentate phosphorus ligand of the present invention combined with a transition metal to form a catalyst complex (chelate), and the composition further includes one or more Lewis acid catalyst promoters (Lewis acid). This catalyst composition is particularly suitable for the hydrocyanation reaction of olefins, especially for the hydrocyanation reaction of monolefins such as 3-pentenenitrile.

[0041] In the catalyst composition, any suitable transition metal can be used as the transition metal, and the preferred metal is a metal of Group VIII of the periodic table, especially nickel. Nickel, as a catalytic metal for hydrocyanation and / or isomerization reactions, is an ideal source of zero-valent nickel.

[0042] In the present invention, the ligand in the zero-valent nickel complex can be replaced by an organophosphorus ligand and used as a source of nickel. On the other hand, divalent nickel compounds can also be used as a nickel source by reacting with a reducing agent. Suitable divalent nickel compounds include compounds with the chemical formula NiY2, where Y represents a halide, carboxylate, or acetylacetonate. Suitable reducing agents include metal borohydrides, metal aluminum hydrides, metal alkyls, Zn, Fe, Al, Na, or H2, etc.

[0043] The catalyst composition may further include one or more Lewis acid promoters that can enhance the activity and selectivity of the catalyst system. The Lewis acid promoter can be an inorganic or organometallic compound, and at least one element can be selected from metals such as scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium, zirconium, niobium, or molybdenum. For example, compounds such as ZnBr2, ZnI2, ZnCl2, ZnSO4, CuCl, CuCl2, FeI, FeCl3, FeCl2, TiCl4, TiCl3, MnCl2, AlCl3, ZrCl4, and NbCl2 are all suitable Lewis acid promoters. The molar ratio of the Lewis acid promoter to nickel is usually between 1:16 and 50:1.

[0044] For example, adiponitrile (ADN) can be formed through a series of reactions shown by the following equations.

[0045]

[0046] According to the abbreviations used herein, BD is 1,3-butadiene, 2PN is 2-pentanenitrile, 3PN is 3-pentenenitrile, 4PN is 4-pentanenitrile, 2M2BN is 2-methyl-2-butenenitrile, 2M3BN is 2-methyl-1,3-butadiene nitrile. MGN is 2-methylglutaronitrile, and ADN is adiponitrile.

[0047] Adiponitrile (ADN) can be prepared through the following reaction pathway: First, 3-pentanenitrile reacts with hydrogen cyanide and, after being promoted by a catalyst, adiponitrile is formed. Depending on the raw materials and conditions used, the adiponitrile content in the product reaches a relatively high level, and by-products such as 2-methylglutaronitrile (MGN) may also be produced.

[0048] According to one embodiment of the present invention, the synthesis process of adiponitrile includes three steps: Preparation of the catalyst composition (i.e., steps S1 - S3 corresponding to the preparation method of the catalyst composition of the present invention): Operate under the protection of an inert gas (such as nitrogen or helium). Use nickel chloride as the nickel source, mix it with a novel bidentate phosphorus ligand and 3 - pentenenitrile as a complexing agent, and add a strong reducing agent (such as zinc powder) for a reduction reaction to generate a catalyst containing zero - valent nickel. This catalyst composition also includes zinc chloride as a Lewis acid catalyst promoter, and the molar ratio of the promoter to nickel in the catalyst is in the range of 1:20 to 50:1.

[0049] Hydrocyanation reaction to produce adiponitrile: In the catalyst composition obtained above, add an appropriate amount of hydrocyanic acid (HCN) to the reaction zone, and a hydrocyanation reaction occurs to produce adiponitrile. This reaction is usually carried out in an appropriate reactor, such as a continuous stirred reactor or a bubble column reactor, in a temperature range of about 25°C to 150°C and a pressure range of 1.03 bar to 20.7 bar. The molar ratio of 3 - pentenenitrile to hydrogen cyanide can be adjusted between 1:1 and 10:1, and the molar ratio of hydrocyanic acid to the catalyst is between 300:1 and 2000:1.

[0050] Product separation: After the reaction is completed, unreacted hydrocyanic acid, 3 - pentenenitrile, adiponitrile and other products and by - products are separated by vacuum distillation. The catalyst is recovered by liquid - liquid extraction and recycled for reuse. In addition, the products are further separated and purified by distillation to finally obtain high - purity adiponitrile.

[0051] Through the above three steps, adiponitrile can be prepared with high selectivity and high yield, and the catalyst recovery efficiency is high, providing an ideal catalytic system for industrial application.

[0052] The following provides examples combined with actual parameters to expand the above - mentioned technical solutions of the present invention: Example 1:

[0053] This example provides a catalyst composition of a bidentate phosphorus ligand, its preparation method and application. The catalyst composition of the bidentate phosphorus ligand includes a bidentate phosphorus ligand, a nickel catalyst and at least one Lewis acid promoter. The bidentate phosphorus ligand includes a skeleton with a 3,3 - bis(methoxy) - 5,5 - dimethyl - 2,2 - bisphenol structure, wherein the hydrogen atoms of the hydroxyl groups are respectively replaced by monophosphine and monophosphite ligand substituents; the chemical formula of the bidentate phosphorus ligand is: ; The Lewis acid promoter is ZnBr2 and MnCl2, the nickel catalyst is a zero - valent nickel catalyst, and the molar ratio of the Lewis acid promoter to nickel is 25:8; This embodiment also provides a method for preparing a catalyst composition of the bidentate phosphorus ligand, comprising the following steps: S1: Under the protection of an inert gas, a divalent nickel compound, a bidentate phosphorus ligand, and a reaction medium are mixed, and heated and stirred to form a chelating complex system; S2: After cooling the mixed system, a reducing agent is added for a reduction reaction, and continuously stirred to form a catalyst composition containing zero-valent nickel; S3: Solid impurities are removed by filtration to obtain the catalyst composition of the bidentate phosphorus ligand.

[0054] The present invention also provides an application of the catalyst composition of the bidentate phosphorus ligand, and the application includes using the catalyst composition of the bidentate phosphorus ligand in the preparation of adiponitrile, comprising the following steps: A1: The catalyst composition of the bidentate phosphorus ligand is mixed with 3-pentenenitrile and a cyanide source in a reactor, the cyanide source is hydrocyanic acid or its precursor cyanohydrin, and the water content of the hydrocyanic acid is less than 250 ppm; A2: A hydrocyanation reaction is carried out in a temperature range of 25-150 °C and a pressure range of 1.03-20.7 bar, the molar ratio of hydrocyanic acid to 3-pentenenitrile is 5:1, and the molar ratio of hydrocyanic acid to the catalyst composition of the bidentate phosphorus ligand is 1150:1; A3: After the reaction is completed, the reaction solution obtained in step A2 is subjected to vacuum distillation treatment to separate and recover the adiponitrile product and unreacted components, and at the same time, an extractant is used to recover the catalyst component to achieve catalytic recycling.

[0055] Example 2: This embodiment provides a catalyst composition of a bidentate phosphorus ligand, a preparation method and an application thereof. The catalyst composition of the bidentate phosphorus ligand includes a bidentate phosphorus ligand, a nickel catalyst, and at least one Lewis acid promoter. The bidentate phosphorus ligand includes a skeleton having a 3,3'-bis(methoxy)-5,5-dimethyl-2,2-bisphenol structure, wherein the hydrogen atoms of the hydroxyl groups are respectively replaced by monophosphine and monophosphite ligand substituents; the chemical formula of the bidentate phosphorus ligand is: ; The Lewis acid promoter is NbCl2, the nickel catalyst is NiCl2, the reducing agent is Na metal, and the molar ratio of the Lewis acid promoter to nickel is 1:16; This embodiment also provides a method for preparing a catalyst composition of the bidentate phosphorus ligand, comprising the following steps: S1: Under the protection of an inert gas, a divalent nickel compound, a bidentate phosphorus ligand, and a reaction medium are mixed, and heated and stirred to form a chelating complex system; S2: After cooling the mixed system, a reducing agent is added for a reduction reaction, and continuous stirring is carried out to form a catalyst composition containing zero-valent nickel; S3: Solid impurities are removed by filtration to obtain the catalyst composition of the bidentate phosphorus ligand.

[0056] The present invention also provides an application of the catalyst composition of the bidentate phosphorus ligand, and the application includes using the catalyst composition of the bidentate phosphorus ligand in the preparation of adiponitrile, including the following steps: A1: The catalyst composition of the bidentate phosphorus ligand is mixed with 3-pentenenitrile and a cyanide source in a reactor, the cyanide source is hydrocyanic acid or its precursor cyanohydrin, and the water content of the hydrocyanic acid is less than 250 ppm; A2: A hydrocyanation reaction is carried out in a temperature range of 25-150 °C and a pressure range of 1.03-20.7 bar. The molar ratio of hydrocyanic acid to 3-pentenenitrile is 1:1, and the molar ratio of hydrocyanic acid to the catalyst composition of the bidentate phosphorus ligand is 300:1; A3: After the reaction is completed, the reaction solution obtained in step A2 is subjected to vacuum distillation treatment to separate and recover the adiponitrile product and unreacted components, and at the same time, an extractant is used to recover the catalyst components to achieve catalytic recycling.

[0057] Example 3: This example provides a catalyst composition of a bidentate phosphorus ligand, its preparation method and application. The catalyst composition of the bidentate phosphorus ligand includes a bidentate phosphorus ligand, a nickel catalyst and at least one Lewis acid promoter, and the bidentate phosphorus ligand includes a skeleton having a 3,3,-bis(methoxy)-5,5-dimethyl-2,2-bisphenol structure, wherein the hydrogen atoms of the hydroxyl groups are respectively replaced by monophosphine and monophosphite ligand substituents; the chemical formula of the bidentate phosphorus ligand is: ; The Lewis acid promoter is CuCl, CuCl2, FeI, and the nickel catalyst is nickel acetylacetonate (Ni(acac)2), where acac represents the acetylpyruvate ion (C5H7O2 - ), and the molar ratio of the Lewis acid promoter to nickel is 50:1; This example also provides a preparation method of the catalyst composition of the bidentate phosphorus ligand, including the following steps: S1: Under the protection of an inert gas, a divalent nickel compound is mixed with a bidentate phosphorus ligand and a reaction medium, and heating and stirring are carried out to form a chelating complex system; S2: After cooling the mixed system, a reducing agent is added for a reduction reaction, and continuous stirring is carried out to form a catalyst composition containing zero-valent nickel; S3: Remove solid impurities by filtration to obtain the catalyst composition of the bidentate phosphorus ligand.

[0058] The present invention also provides an application of the catalyst composition of the bidentate phosphorus ligand, and the application includes using the catalyst composition of the bidentate phosphorus ligand in the preparation of adiponitrile, including the following steps: A1: Mix the catalyst composition of the bidentate phosphorus ligand with 3-pentenenitrile and a cyanide source in a reactor. The cyanide source is hydrocyanic acid or its precursor cyanohydrin, and the water content of the hydrocyanic acid is less than 250 ppm. A2: Carry out a hydrocyanation reaction in a temperature range of 25 - 150 °C and a pressure range of 1.03 - 20.7 bar. The molar ratio of hydrocyanic acid to 3-pentenenitrile is 10:1, and the molar ratio of hydrocyanic acid to the catalyst composition of the bidentate phosphorus ligand is 2000:1. A3: After the reaction is completed, carry out vacuum distillation on the reaction solution obtained in step A2 to separate and recover the adiponitrile product and unreacted components, and at the same time use an extractant to recover the catalyst components to achieve catalytic recycling.

[0059] The following provides examples combined with actual operations and specific data to further illustrate the implementation mode of the present invention: Example 4: Based on the operation content of Examples 1 to 3, this example further optimizes the preparation method and application process of the bidentate phosphorus ligand catalyst composition, and specific reaction conditions, raw material quality, and step details are retained during this process. The following is the specific operation process of Example 4: This example provides a catalyst composition of a bidentate phosphorus ligand, its preparation method, and application. The catalyst composition is prepared by the following method: Step S1: Prepare the catalyst composition S1: In a 500 mL flask, under argon protection, suspend 18.6 g (85 mmol) of NiBr2 in 13 g of 3-pentenenitrile. Then add 100 g of a chelating solution containing 86 mmol of ligand A, and stir the mixture at 80 °C for 10 minutes.

[0060] S2: After the mixture is cooled to 50 °C, add 8 g of Zn powder (122 mmol, 1.4 equivalents), and continue to stir at 50 °C for 5 hours. After the reaction is completed; S3: Obtain a zero-valent nickel catalyst by filtration. At this time, the measured Ni(0) content of the zero-valent nickel is 2.0%, and the molar ratio of zero-valent nickel Ni(0) to the bidentate phosphorus ligand A is 1:2:4.

[0061] The chemical formula of the bidentate phosphorus ligand is: ; The present invention also provides an application of the catalyst composition of the bidentate phosphorus ligand, and the application includes using the catalyst composition of the bidentate phosphorus ligand in the preparation of adiponitrile, comprising the following steps: Preparation of adiponitrile: A1: Take 100 g of the zero-valent nickel catalyst prepared in step S1 and add it to a 2000 mL high-pressure reactor. Under nitrogen protection, add zinc chloride as a Lewis acid so that the molar ratio of zinc chloride to the zero-valent nickel catalyst is 2:1, and the molar ratio of 3-pentenenitrile to the zero-valent nickel catalyst is 160:1. Add an appropriate amount of bidentate phosphorus ligand A to the reaction system; start stirring and raise the temperature to 70-90 °C. Then, add acetone cyanohydrin to the high-pressure reactor by controlling the flow rate.

[0062] A2: Perform hydrocyanation reaction in the temperature range of 25-150 °C and the pressure range of 1.03-20.7 bar. The molar ratio of hydrocyanic acid to 3-pentenenitrile is 5:1, and the molar ratio of hydrocyanic acid to the bidentate phosphorus ligand catalyst composition is 1150:1. After the feeding of acetone cyanohydrin is completed, keep the reaction solution reacting at normal pressure for 4.5 hours to complete the hydrocyanation reaction.

[0063] A3: After the reaction is completed, use vacuum distillation to separate and recover unreacted hydrocyanic acid, 3-pentenenitrile, adiponitrile and other by-products from the reaction mixture. The catalyst and the phosphorus ligand are extracted and recovered by an extractant. Through this step, purified adiponitrile and by-products are obtained, and at the same time, the catalyst is recovered for reuse.

[0064] Product analysis and results: Using gas chromatography with an internal standard (benzonitrile) for analysis, the yields of adiponitrile (ADN) and 2-methylglutaronitrile (MGN) are measured to be 92%, and the ratio of adiponitrile to 2-methylglutaronitrile is 13:1, showing high selectivity and high yield.

[0065] This example demonstrates the excellent performance of the catalyst composition (zero-valent nickel, bidentate phosphorus ligand and Lewis acid) of the present invention in the hydrocyanation reaction. Through streamlined reaction steps and an efficient catalytic system, both the selectivity and conversion rate of adiponitrile have been significantly improved, and at the same time, the recovery and recycling of the catalyst have achieved cost savings and optimization of industrial applications.

[0066] Through the above embodiments, it is further proved that the catalyst composition of the present invention has remarkable catalytic activity and high selectivity in the hydrocyanation reaction. Specifically, the combination of zero-valent nickel, bidentate phosphorus ligand and Lewis acid promoter can effectively promote the hydrocyanation reaction of 3-pentenenitrile to produce adiponitrile with high purity, and the by-products are well controlled. In addition, the catalyst composition of the present invention has excellent stability and recyclability. After being treated by the steps of vacuum distillation and extraction, the catalyst can be recycled, thus significantly reducing the production cost and improving the economy and sustainability of the overall reaction. The technical principle of the present invention lies in the synergistic effect of the bidentate phosphorus ligand and nickel, which can enhance the electronic properties of the catalyst and improve the catalytic efficiency. The introduction of the Lewis acid promoter further optimizes the selectivity of the catalytic reaction, especially showing significant advantages in the selectivity and conversion rate in the hydrocyanation reaction. In the application method of the present invention, by precisely controlling the composition, reaction temperature, pressure and reaction time of the catalyst, the technical problems such as insufficient catalyst activity, poor selectivity and difficult catalyst recovery in the prior art are successfully overcome.

[0067] Therefore, the present invention not only provides an efficient catalyst composition, but also provides a more economical and environmentally friendly solution for the industrial preparation of adiponitrile, which has important practical application value for improving the efficiency of related chemical reactions and reducing production costs.

[0068] In the description of the present application, the descriptions referring to terms such as "one embodiment", "some embodiments", "in this embodiment", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without conflict, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0069] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A catalyst composition of a bidentate phosphorus ligand, characterized in that: The bidentate phosphorus ligand catalyst composition comprises a bidentate phosphorus ligand, a nickel catalyst and at least one Lewis acid promoter, and the bidentate phosphorus ligand comprises a skeleton having a 3,3-di(methoxy)-5,5-dimethyl-2,2-bisphenol structure, wherein the hydrogen atoms of the hydroxyl groups are substituted by monophosphine and monophosphite ligand substituent groups, respectively.

2. The catalyst composition of bidentate phosphorus ligand according to claim 1, characterized in that: In the bidentate phosphorus ligand, the monophosphine and monophosphite ligand substituent groups are o-methylphenoxyphosphine P(OR1)2 and diphenylphosphine P(R2)2, respectively, wherein R1 is o-methylphenyl and R2 is phenyl.

3. The catalyst composition of bidentate phosphorus ligand according to claim 2, characterized in that: The chemical formula of the bidentate phosphorus ligand is: 。 4. The catalyst composition of bidentate phosphorus ligand according to claim 1, characterized in that: The nickel catalyst is a zero-valent nickel catalyst or a mixture of a divalent nickel catalyst and a reducing agent.

5. The catalyst composition of bidentate phosphorus ligand according to claim 4, characterized in that: The divalent nickel catalyst is a compound with a molecular formula of NiY2, wherein Y is a halide, a carboxylate or an acetylacetonate; the reducing agent is one of metal borohydride, metal aluminum hydride, metal alkyl, Zn, Fe, Al, Na and H2.

6. The catalyst composition of bidentate phosphorus ligand according to claim 1, characterized in that: The Lewis acid promoter is an inorganic or organic metal compound, and at least one element in the inorganic or organic metal compound is selected from scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium, zirconium, niobium and molybdenum.

7. The catalyst composition of bidentate phosphorus ligand according to claim 6, characterized in that: The Lewis acid promoter is one of ZnBr2, ZnI2, ZnCl2, ZnSO4, CuCl, CuCl2, FeI, FeCl3, FeCl2, TiCl4, TiCl3, MnCl2, AlCl3, ZrCl4 or NbCl2, and the molar ratio of the Lewis acid promoter to nickel is (1-50): (16-1).

8. A method for preparing the bidentate phosphorus ligand catalyst composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Under inert gas protection conditions, a divalent nickel compound, a bidentate phosphorus ligand and a reaction medium are mixed, and heated and stirred to form a chelate complex system; S2: After cooling the mixed system, adding a reducing agent to carry out a reduction reaction, and continuously stirring to form a catalyst composition containing zero-valent nickel; S3: removing solid impurities by filtering to obtain the bidentate phosphorus ligand catalyst composition.

9. Use of a catalyst composition containing a bidentate phosphorus ligand according to any one of claims 1 to 7, characterized in that: The application includes using the bidentate phosphorus ligand catalyst composition in the preparation of adiponitrile, comprising the following steps: A1: mixing the bidentate phosphorus ligand catalyst composition with olefin and cyanide source in a suitable solvent, and maintaining suitable temperature and pressure conditions in the reaction system; A2: performing a hydrocyanation reaction at a reaction time of 1 to 10 hours and a reaction temperature of 50° C. to 120° C. to obtain the adiponitrile product; A3: The reaction mixture is subjected to reduced pressure distillation to separate and recover unreacted hydrocyanic acid, 3-pentenenitrile, product adiponitrile and by-products, and the catalyst system is recovered by extraction.

10. Use of the catalyst composition of the bidentate phosphorus ligand according to claim 9, characterized in that: The application comprises the following steps: A1: mixing the bidentate phosphorus ligand catalyst composition with 3-pentenenitrile and a cyanide source in a reactor, wherein the cyanide source is hydrocyanic acid or its precursor cyanohydrin, and the water content of the hydrocyanic acid is less than 250 ppm; A2: The hydrocyanation reaction is carried out in a temperature range of 25-150°C and a pressure range of 1.03-20.7 bar, the molar ratio of hydrocyanic acid to 3-pentenenitrile is (1-10):1, and the molar ratio of hydrocyanic acid to the bidentate phosphorus ligand catalyst composition is (300-2000):1; A3: After the reaction is completed, the reaction solution obtained in step A2 is subjected to reduced pressure distillation to separate and recover the adiponitrile product and unreacted components, and at the same time, an extractant is used to recover the catalyst components to achieve a catalytic cycle.

Images