Catalyst for hydrogenation of cyano compounds, process for its preparation and use

Abstract

The application provides a cyan compound hydrogenation catalyst and a preparation method and application thereof. The method comprises the following steps: providing a carrier; treating the carrier with a promoter to obtain a treated carrier; impregnating the treated carrier with a solution containing a noble metal salt and a solution containing a transition metal to obtain a catalyst precursor; and performing heat treatment and reduction on the catalyst precursor to obtain the catalyst. The catalyst has excellent catalytic performance, can be used for catalyzing the hydrogenation reaction of cyan compounds, has excellent selectivity of target products, and inhibits the formation of by-products. In addition, the catalyst has excellent stability, can be continuously used for catalyzing the reaction for a long time, and the catalytic performance does not obviously decrease.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalysis, more particularly to a carbon-based carrier supported catalyst, a method for preparing the catalyst and a method for hydrogenation reduction of a cyano-containing compound using the catalyst. BACKGROUND

[0002] Nylon materials are a kind of widely used synthetic materials, which are various, including PA6, PA66, PA11, PA12, PA46, PA610, PA612, PA1010, etc. Different nylon materials have a lot of advantages, such as excellent mechanical properties, and also have heat resistance, wear resistance, chemical resistance, self-lubricity, flame retardancy and low friction coefficient, and people widely use them in many different fields according to their different properties.

[0003] Nylon 12 (also known as PA12) is a high-performance aliphatic nylon with an average of 12 carbon atoms in the monomer unit, which is a kind of special long-chain nylon. It not only has the general characteristics of conventional nylons such as nylon 6 and nylon 66, but also has the advantages of small water absorption, small relative density, good air tightness, good electrical insulation performance, resistance to friction, resistance to fuel, chemical resistance, good weather resistance, good noise reduction effect, etc. It is widely used in high-tech fields such as automobile manufacturing, pressure conveying pipeline, wire and cable, 3D printing, medical devices, etc.

[0004] At present, the mainstream production process of PA12 is oxidation oximation method, and many manufacturers use the mainstream process route of oxidation oximation method with butadiene as raw material to produce PA12. This route has long process flow, and open-loop polymerization needs to add acid for catalytic reaction at high temperature, which is difficult to operate and requires high equipment.

[0005] For the purpose of reducing the process steps of PA12 production, simplifying the process route, reducing the energy consumption and expenditure of the reaction, people have developed different processes based on different ideas. Representative new processes include preparing 12-aminododecanoic acid (12-ADA) by cyclohexanone oxidation, cracking, hydrogenation reduction, and then polycondensation to obtain PA12; preparing 12-ADA by 10-undecylenic acid, substitution, cyanation, hydrogenation reduction, and then polycondensation to obtain PA12. These two newly developed processes have the advantages of short process route, low investment, and easy purchase of raw materials, but these processes need to obtain 12-ADA product by hydrogenation reduction of cyan compound 11-cyanoundecanoic acid (11-CUA), which requires the use of high-performance supported catalysts for hydrogenation reduction reaction. The preparation of these catalysts often requires multiple impregnation / reduction, which is complicated, has a low loading of active ingredients, and has low selectivity of the target product in the hydrogenation reaction, inevitably generating isomerization byproducts, affecting the quality of the final product. In addition, the stability of the catalysts in the prior art is poor, and the catalytic activity decreases rapidly or even completely loses catalytic activity as the catalytic reaction proceeds, resulting in the need to replace the catalysts frequently, further increasing the production cost.

[0006] To solve the above problems, many researchers in the field have conducted a lot of research, but so far they have not been able to develop a technology that can effectively solve the above problems. Therefore, there is an urgent need for a cyan compound hydrogenation catalyst with excellent catalytic performance and strong stability, especially for long-chain cyan compound hydrogenation catalysts, to reduce side reactions during 11-CUA hydrogenation reaction, improve the selectivity of 11-CUA hydrogenation reaction, and reduce the cost of PA12 production. SUMMARY

[0007] To solve the above problems, the inventors of the present application have conducted in-depth research and successfully developed a catalyst, its preparation method and application, thereby effectively solving the long-standing problems in the prior art.

[0008] The first aspect of the present application provides a method for preparing a catalyst, the method comprising:

[0009] Step one: providing a carrier, the carrier being selected from at least one of activated carbon, silicon carbide, porous carbon, carbon nanotubes, carbon black, fullerene, graphene, fluorescent carbon, carbon fiber, vapor deposition carbon, carbon felt, graphite felt;

[0010] Step two: treating the carrier with a promoter to obtain a treated carrier, the promoter being selected from at least one of ethylenediaminetetraacetic acid, tetramethylethylenediamine, triethanolamine, tributylphosphine, triphenylphosphine, trihexyl phosphite, tributyl phosphite, triethyl phosphite, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid;

[0011] Step three: impregnating the treated support with a solution containing a noble metal salt, the noble metal being selected from the group consisting of ruthenium, rhodium, palladium, or a combination thereof, and a solution containing a transition metal, the transition metal being selected from at least one of the group consisting of cobalt, iron, nickel, copper, zinc, tin, bismuth;

[0012] Step four: heat treating and reducing the catalyst precursor to obtain a catalyst.

[0013] According to one embodiment of the present application, in the step two, the aqueous solution of the promoter is mixed with the support, and the weight ratio of the promoter contained in the aqueous solution to the support is 0.1-10:1.

[0014] According to another embodiment of the present application, in the step two, the concentration of the aqueous solution of the promoter is 0.20-3.0 moles / liter; and the volume of the aqueous solution to the weight of the support is 10-1000 milliliters of solution per 100 grams of support.

[0015] According to another embodiment of the present application, in the step two, the support is soaked in the aqueous solution of the promoter for 0.5-12 hours, and then the support is separated from the aqueous solution.

[0016] According to another embodiment of the present application, in the step three, all of the noble metal salt and all of the transition metal salt are absorbed in the support.

[0017] According to another embodiment of the present application, in the step three, the weight of the noble metal (calculated as pure noble metal) is 0.05-5 parts by weight based on 100 parts by weight of the support. According to another embodiment of the present application, in the step three, the weight of the transition metal (calculated as pure transition metal) is 0.1-15 parts by weight.

[0018] According to another embodiment of the present application, in the step three, in the step four, the catalyst precursor is first heated to 300-500°C under an inert atmosphere or vacuum, and then reduced under a reducing atmosphere and at a temperature of 300-500°C to obtain a catalyst.

[0019] A second aspect of the present application provides a catalyst for a reduction reaction, in particular a catalyst for a reduction reaction of a compound containing a nitrile group, comprising:

[0020] i) a support selected from at least one of the group consisting of activated carbon, silicon carbide, porous carbon, carbon nanotube, carbon black, fullerene, graphene, fluorescent carbon, carbon fiber, vapor-deposited carbon, carbon felt, graphite felt;

[0021] ii) an optional promoter selected from at least one of ethylenediaminetetraacetic acid, tetramethylethylenediamine, triethanolamine, tributylphosphine, triphenylphosphine, trihexylphosphite, tributylphosphite, triethylphosphite, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid;

[0022] iii) a noble metal having at least a majority of its valence in the 0 valence state, the noble metal being selected from at least one of ruthenium, rhodium, palladium, or a combination thereof;

[0023] iv) a transition metal having at least a majority of its valence in the 0 valence state, the transition metal being selected from at least one of cobalt, iron, nickel, copper, zinc, tin, bismuth;

[0024] The content of the promoter is 0.1-20 parts by weight, the content of the noble metal is 0.05-5 parts by weight, and the content of the transition metal is 0.1-15 parts by weight, based on 100 parts by weight of the carrier.

[0025] According to one embodiment of the present application, the catalyst is prepared by the method of the present application.

[0026] A third aspect of the present application provides a method for hydrogenation reduction of a compound containing a cyano group, the method comprising reacting the cyano group contained in the compound with hydrogen gas in the presence of the catalyst of the present application to convert the cyano group (-CN) into an aminomethylene group (-CH2-NH2).

[0027] According to one embodiment of the present application, the compound containing a cyano group comprises a C1-C16 nitrile, a C2-C16 dinitrile.

[0028] According to one embodiment of the present application, the compound containing a cyano group has the following structure shown in Formula I:

[0029]

[0030] wherein A is selected from the group consisting of a linear or branched C1-C16 alkylene group, a linear or branched halogenated C1-C16 alkylene group, a C3-C16 cycloalkylene group, a halogenated C3-C16 cycloalkylene group, a C6-C22 arylene group, a halogenated C6-C22 arylene group.

[0031] According to another embodiment of the present application, the hydrogenation reduction is carried out at a temperature of 80-200°C, under a hydrogen pressure of 0.2-5.0 MPa, for 0.2-5 hours. BRIEF DESCRIPTION OF DRAWINGS

[0032] Various embodiments of the application are discussed in the following detailed description with reference to the accompanying drawings. However, it should be noted that the drawings shown herein and the embodiments described below are merely preferred embodiments of the application, and the scope of the application is defined by the claims, not merely by the preferred embodiments.

[0033] Figure 1 A flow chart showing the process according to the application is shown.

[0034] Figure 2 A reaction mechanism for the hydrogenation of a specific cyano-containing compound using the catalyst of the application is shown, which hydrogenation product can be used to synthesize nylon 12. DETAILED DESCRIPTION

[0035] The ranges disclosed herein are presented in terms of their lower and upper limits. There can be one or more lower limits and one or more upper limits. The ranges are presented as a series of lower and upper limits. The selected lower and upper limits define the boundaries of the particular range. All ranges disclosed herein are inclusive and combinable, i.e., all ranges are combinable. For example, a range of 60-120 and a range of 80-110 are combinable to form a range of 60-110 and a range of 80-120. Further, if a minimum range value of 1 and a maximum range value of 3 are listed, then the following ranges are also contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0036] In the present application, unless otherwise stated, the numerical range "a-b" indicates a shorthand for the inclusion of any and all combinations of real numbers between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed herein, and "0-5" is a shorthand for the inclusion of these numerical combinations.

[0037] In the present application, unless otherwise stated, all embodiments and preferred embodiments mentioned herein can be combined with each other to form new technical solutions.

[0038] In the present application, unless otherwise stated, all technical features and preferred features mentioned herein can be combined with each other to form new technical solutions.

[0039] In the present application, unless otherwise stated, the term "comprising" mentioned herein indicates an open-ended, and can also be closed. For example, the term "comprising" can mean that it can also include other components not listed, or can only include the listed components.

[0040] The catalyst of the present application is a supported catalyst with improved formulation, in which the combination of noble metal, transition metal, promoter and support can produce a good synergistic effect, with the effects of improving hydrogenation catalytic performance, reducing by-product generation, prolonging catalyst life, etc., which can greatly improve production efficiency and reduce production cost.

[0041] The catalyst according to the present application is designed to hydrogenate and reduce a compound containing a cyano group, such that the cyano group (-CN) in the compound is converted to aminomethylene (-CH2-NH2). According to one embodiment of the present application, only the cyano group in the compound containing a cyano group undergoes the hydrogenation and reduction reaction, while other parts of the molecule do not react. According to one embodiment of the present application, the compound containing a cyano group includes C1-C16 nitrile, C2-C16 dinitrile, such as adiponitrile. According to one embodiment, the compound containing a cyano group has the structure shown in the following Formula I:

[0042]

[0043] wherein A is selected from the group consisting of linear or branched C1-C16 alkylene, linear or branched halogenated C1-C16 alkylene, C3-C16 cycloalkylene, halogenated C3-C16 cycloalkylene, C6-C22 arylene, halogenated C6-C22 arylene. According to one exemplary embodiment, A is selected from the group consisting of linear or branched C1-C12 alkylene, linear or branched halogenated C1-C12 alkylene, C3-C12 cycloalkylene, halogenated C3-C12 cycloalkylene, C6-C16 arylene, halogenated C6-C16 arylene. According to one exemplary embodiment, A is selected from the group consisting of linear or branched C1-C10 alkylene, linear or branched halogenated C1-C10 alkylene, C3-C10 cycloalkylene, halogenated C3-C10 cycloalkylene, C6-C10 arylene, halogenated C6-C10 arylene. According to another exemplary embodiment, A is selected from the group consisting of linear or branched C1-C8 alkylene, linear or branched halogenated C1-C8 alkylene, C3-C8 cycloalkylene, halogenated C3-C8 cycloalkylene, C6-C12 arylene, halogenated C6-C12 arylene. According to another exemplary embodiment, A is selected from the group consisting of linear or branched C1-C6 alkylene, linear or branched halogenated C1-C6 alkylene, C3-C6 cycloalkylene, halogenated C3-C6 cycloalkylene, C6-C8 arylene, halogenated C6-C8 arylene. Wherein halogenated means substituted with one, two, three, four, five, six or more halogen atoms, such as fluorine, chlorine, bromine, iodine, or combinations thereof.

[0044] According to an exemplary embodiment of the present application, the cyano-containing compound is a long-chain cyano compound, for example, having the structure shown in Formula I above, and A is a C6-C16 alkylene group, for example, a C6-C12 alkylene group, or a C8-C10 alkylene group. In the following description, the hydrogenation reduction of 11-cyanoundecanoic acid (11-CUA), i.e., HOC(O)-(CH2) 10 The hydrogenation reduction reaction using the catalyst of the present application is described by way of example with respect to the hydrogenation reduction of 11-cyanoundecanoic acid (11-CUA), i.e., HOC(O)-(CH2)

[0045] As shown in Formula II below, the cyano group in 11-CUA is hydrogenated and reduced in the presence of the catalyst of the present application to form 12-amino-dodecanoic acid (12-ADA), which can then be used as a starting material to synthesize nylon 12 (PA-12) through a condensation reaction. Figure 2

[0046] A flowchart showing the method used to prepare the catalyst of the present application is shown in Formula III below. As shown in Formula III, the catalyst of the present application can be synthesized by a method comprising the following steps: Figure 1 Figure 1

[0047] Step 1: providing a support,

[0048] Step 2: treating the support with a promoter to produce a treated support,

[0049] Step 3: impregnating the treated support with a solution comprising a noble metal salt and a solution comprising a transition metal to produce a catalyst precursor,

[0050] Step 4: heat treating and reducing the catalyst precursor to produce the catalyst.

[0051] According to an embodiment of the present application, the support is selected from at least one of activated carbon, silicon carbide, porous carbon, carbon nanotubes, carbon black, fullerene, graphene, fluorescent carbon, carbon fiber, vapor-deposited carbon, carbon felt, and graphite felt. According to a specific embodiment of the present application, the support is selected from at least one of activated carbon, silicon carbide, and carbon nanotubes.

[0052] In the second step of the present application, the promoter is prepared as an aqueous solution, and then the support is added to the aqueous solution of the promoter and soaked and mixed. According to an embodiment of the present application, after soaking, the excess aqueous solution can be removed, for example, by filtration, decantation, centrifugation, and then the soaked support is dried to produce the treated support.

[0053] ​​According to an embodiment of the present application, the accelerant is selected from at least one of the following: ethylenediaminetetraacetic acid, tetramethylethylenediamine, triethanolamine, tributylphosphine, triphenylphosphine, trihexylphosphite, tributylphosphite, triethylphosphite, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid; for example, the accelerant can be selected from at least one of the following: ethylenediaminetetraacetic acid, triethanolamine, polyvinylpyrrolidone, tributylphosphite, triphenylphosphine.

[0054] According to an embodiment of the present application, the concentration of the aqueous solution of the accelerant is 0.2-3.0 moles / liter, for example, 0.3-2.8 moles / liter, or 0.5-2.6 moles / liter, or 0.6-2.5 moles / liter, or 0.8-2.2 moles / liter, or 0.5-1.0 moles / liter, or 0.5-2.0 moles / liter, or 0.5-1.5 moles / liter, or within a range of values obtained by combining any two of the above-mentioned end values.

[0055] According to an embodiment of the present application, the weight of the carrier to be treated and the volume of the aqueous solution of the accelerant used can satisfy the following ratio: 10-1000 milliliters of the aqueous solution of the accelerant is used per 100 grams of the carrier, for example, 20-900 milliliters of the aqueous solution of the accelerant is used per 100 grams of the carrier, or 50-800 milliliters of the aqueous solution of the accelerant is used per 100 grams of the carrier, or 60-500 milliliters of the aqueous solution of the accelerant is used per 100 grams of the carrier, or 70-400 milliliters of the aqueous solution of the accelerant is used per 100 grams of the carrier, or 80-200 milliliters of the aqueous solution of the accelerant is used per 100 grams of the carrier, or 90-100 milliliters of the aqueous solution of the accelerant is used per 100 grams of the carrier, or within a range of values obtained by combining any two of the above-mentioned end values.

[0056] According to another embodiment of the present application, by adjusting the volume and concentration of the aqueous solution of the accelerant used and the weight of the carrier, the ratio of the weight of the accelerant in the aqueous solution of the accelerant to the weight of the carrier is 0.1:1 to 10:1, for example, 0.2:1 to 8:1, or 0.3:1 to 5:1, or 0.5:1 to 3:1, or 0.6:1 to 2:1, or 0.8:1 to 1:1, or within a range of values obtained by combining any two of the above-mentioned end values.

[0057] According to one embodiment of the present application, the soaking / immersion of the support in the aqueous solution of the promoter can be carried out at a temperature ranging from room temperature to 1000C, such as from 100C to 800C, or from 150C to 600C, or from 200C to 500C, or from 250C to 400C, or within a range defined by any two of the above-mentioned values taken in combination.

[0058] After the excess of the aqueous solution is removed by filtration, decantation and / or centrifugation, the solid material is heated to dryness to obtain the treated support. According to one embodiment of the present application, the heating to dryness can be carried out at a temperature ranging from 80°C to 1500C, such as from 900C to 1400C, or from 1000C to 1300C, or from 1100C to 1200C, or within a range defined by any two of the above-mentioned values taken in combination. The time of heating to dryness can range from 2 hours to 12 hours, or from 4 hours to 10 hours, or from 6 hours to 8 hours, or within a range defined by any two of the above-mentioned values taken in combination.

[0059] According to one embodiment of the present application, at least a portion of the promoter contained in the above-mentioned solution of the promoter remains in the treated support after the treatment, such as on the surface of the support and in the internal pores. According to another embodiment of the present application, the promoter can be connected to the support only by physisorption, or by bonding through van der Waals forces, coordination bonds, and / or covalent bonds.

[0060] In the third step of the process of the present application, the treated support is impregnated with a solution containing a noble metal salt and a solution containing a transition metal salt to obtain a catalyst precursor. According to one particular embodiment of the present application, all of the solution of the noble metal salt and the solution of the transition metal salt are absorbed into the treated support, without excess liquid being removed.

[0061] The noble metal is selected from the group consisting of ruthenium, rhodium, palladium, or a combination thereof, and the transition metal is selected from at least one of the group consisting of cobalt, iron, nickel, copper, zinc, tin, bismuth. The salt of the noble metal and the salt of the transition metal can be various soluble salts, such as nitrate, sulfate, chloride, formate, acetate, etc., or the noble metal oxide or the transition metal oxide can be dissolved in an aqueous acid or an acidic aqueous solution to obtain an aqueous solution of the corresponding salt.

[0062] According to one embodiment of the present application, the noble metal salt and the transition metal salt can be formed into separate solutions, and separately added to the treated support; or a solution can be formed that includes a mixture of both the noble metal salt and the transition metal salt, and then added to the treated support together. The concentration of the noble metal salt in the solution can be 0.1 to 5 moles / liter, or 0.5 to 4 moles / liter, or 1 to 3 moles / liter, or 1.5 to 2 moles / liter. The concentration of the transition metal salt in the solution can be 0.1 to 5 moles / liter, or 0.5 to 4 moles / liter, or 1 to 3 moles / liter, or 1.5 to 2 moles / liter.

[0063] According to one embodiment of the present application, the noble metal is present in an amount of 0.05 to 5 parts by weight (as pure noble metal) per 100 parts by weight of the support, for example 0.1 to 4 parts by weight, or 0.2 to 3 parts by weight, or 0.5 to 2 parts by weight, or 1 to 1.5 parts by weight, or within a range defined by any two of the above values in combination. According to one embodiment of the present application, the transition metal is present in an amount of 0.1 to 15 parts by weight (as pure transition metal) per 100 parts by weight of the support, for example 0.2 to 10 parts by weight, or 0.5 to 8 parts by weight, or 0.8 to 6 parts by weight, or 1 to 4 parts by weight, or 2 to 3 parts by weight, or within a range defined by any two of the above values in combination.

[0064] The mixing of the aqueous noble metal salt solution / transition metal salt solution with the treated support can be carried out by adding the aqueous salt solution dropwise to the treated support, and then promoting the mixing of the two by stirring or ultrasonication, and then the wet material that has absorbed the liquid can be heated to dry. For example, the heating and drying can be carried out at a temperature of 80 to 150°C, for example a temperature of 90 to 140°C, or 100 to 130°C, or 110 to 120°C, or within a range defined by any two of the above values in combination. The heating and drying can be carried out for a time of 2 to 12 hours, or 4 to 10 hours, or 6 to 8 hours, or within a range defined by any two of the above values in combination. The catalyst precursor is obtained by the above steps.

[0065] In the fourth step of the present application, the catalyst precursor is heated and reduced to obtain the catalyst. According to one embodiment of the present application, the catalyst precursor is first heated under an inert atmosphere or vacuum at a temperature of 300-500°C, and then reduced under a reducing atmosphere at a temperature of 300-500°C to obtain the catalyst. According to one exemplary embodiment of the present application, the inert atmosphere can be a nitrogen atmosphere or an argon atmosphere; the temperature is raised to 300-500°C, for example 350-450°C, or 400-420°C, at a temperature raising rate of 0.5-20°C / min; the reducing atmosphere can be a hydrogen atmosphere, and the hydrogen pressure can be 0.2-20 MPa, for example 0.5-15 MPa, or 1-12 MPa, or 2-10 MPa, or 4-8 MPa, or 5-6 MPa; and the temperature of the reduction process is 300-500°C, for example 350-450°C, or 400-420°C. After the reduction step, the catalyst of the present application is obtained by cooling to room temperature under an inert atmosphere, for example the above-mentioned inert atmosphere.

[0066] According to one embodiment of the present application, after the hydrogen reduction step, at least a majority of the noble metal and the transition metal are reduced to zero valence, and "at least a majority" means that at least 50% of the noble metal ions and the transition metal ions are reduced to zero valence, for example at least 60%, or 70%, or at least 80%, or at least 90%, or at least 95%, or at least 99%, or at least 99.9%. This reduction of a majority of the metal ions to zero valence can be achieved by the reduction operation with hydrogen under the above-mentioned process conditions.

[0067] In one preferred embodiment of the present application, in the finally prepared catalyst, both the noble metal and the transition metal are in zero valence.

[0068] According to another embodiment of the present application, the catalyst used in the preparation of the catalyst of the present application is at least partially retained in the final catalyst. In one specific embodiment of the present application, the content of the promoter is 0.1-20 parts by weight, for example 1-15 parts by weight, or 2-12 parts by weight, or 4-8 parts by weight, or 5-6 parts by weight, based on 100 parts by weight of the carrier.

[0069] According to one embodiment of the present application, the catalyst can be used for the reduction reaction of a compound containing a cyano group, the catalyst can be added to the reactor together with the reactant to be reduced by hydrogenation, hydrogen is filled into the reactor, and then the reaction is carried out. According to one embodiment of the present application, the weight ratio of the catalyst to the reactant to be reduced by hydrogenation can be 1:20 to 1:1, for example, 1:15 to 2:3, or 1:10 to 1:2, or 1:8 to 1:2, or 1:4 to 1:2. The pressure of the hydrogen can be 0.2-10 MPa, for example, 0.5-8 MPa, or 1-6 MPa, or 2-5 MPa, or 3-4 MPa.

[0070] According to one embodiment of the present application, one or more solvents, additives or other aids can also be added in the catalytic hydrogenation reaction.

[0071] The catalyst of the present application can be used for the hydrogenation reaction of a compound containing a cyano group (especially a long-chain cyano compound), the preparation method of the catalyst is simple, convenient to operate and green and environmentally friendly; when applied to the hydrogenation reaction of a compound containing a cyano group (for example, 11-CUA), the by-products generated are less, the conversion rate of the raw material is as high as 99.9%, and the target selectivity can reach more than 99.5%. After the catalyst is continuously used for ten times, it still has excellent catalytic activity and selectivity.

[0072] The present application is described below in the form of specific examples, which aims to better understand the content of the present application. It should be understood that these examples are merely illustrative, but not limiting. The reagents used in the examples are commercially available unless otherwise specified. The methods and conditions used in the examples are conventional methods and conditions unless otherwise specified.

[0073] Examples

[0074] In the following examples, the catalyst of the present application is synthesized and the catalytic activity of the catalyst is investigated by taking the preparation of 12-ADA and 1,6-hexanediamine as an example. However, it should be particularly pointed out that the following examples are only specific examples listed in the present application, but the technical features of the present application are not limited thereto. Any simple change, equivalent replacement or other modification made on the basis of the present application to solve basically the same technical problem and achieve basically the same technical effect is also covered within the protection scope of the present application.

[0075] The raw materials used in the following examples are commercially available analytical pure samples, which are directly used without further purification or treatment.

[0076] Example 1

[0077] (1) 10.0000 g of activated carbon (AC) support was added to 50 mL of 1.0 mol / L aqueous ethylenediaminetetraacetic acid solution, soaked for 4 hours, centrifuged to remove excess aqueous solution, and the wet solid material was dried at 120°C for 8 hours; 0.5174 g of RuCl3·3H2O and 2.0250 g of NiCl2·6H2O were accurately weighed and dissolved in 14 mL of deionized water, stirred until completely dissolved, and the prepared solution was slowly added dropwise to the activated carbon treated with the promoter. The resulting mixture was subjected to ultrasonic treatment for 2 hours, and then the mixture was dried at 120°C for 8 hours. The dried material was transferred to a tube furnace, nitrogen was introduced to replace the air, and the temperature was raised to 350°C at a rate of 5°C / min under a nitrogen atmosphere. Hydrogen was then introduced to replace the single body, and the reduction was carried out at 350°C under a hydrogen atmosphere for 5 hours. Nitrogen was then introduced again, and the temperature was allowed to cool to room temperature under a nitrogen atmosphere, thereby obtaining a 2% Ru 5% Ni / AC catalyst, hereinafter referred to as catalyst 1.

[0078] (2) 5 g of catalyst 1 prepared in step (1), 10 g of 11-CUA, 120 g of 28% ammonia water, and 120 g of n-butanol were placed in a 1 L autoclave, the autoclave was sealed, and the air tightness was tested. After replacing the air in the reactor with nitrogen, and then replacing the nitrogen in the reactor with hydrogen, the temperature was raised to 100°C, the hydrogen pressure in the reactor was increased to 3.0 MPa, and the reaction was carried out for 0.5 hours. The catalyst was recovered by hot filtration, the filtrate was cooled to crystallize, and the product 12-ADA was obtained by suction filtration and drying. The purity of 12-ADA was 98.9% by chromatographic analysis, the content of 12,12'-iminododecanedioic acid was 0.02%, the conversion of 11-CUA was 99.6%, and the selectivity of 12-ADA was 99.2%.

[0079] The above step (2) was repeated ten times using the recovered catalyst, and no significant decrease in conversion and selectivity was observed. The target product 12-ADA can be used for the synthesis of nylon 12.

[0080] Example 2

[0081] (1) 10.0000 g of activated carbon (AC) support was added to 40 mL of 1.0 mol / L triethanolamine aqueous solution, soaked for 8 hours, centrifuged to remove excess aqueous solution, and the wet solid material was dried at 120°C for 8 hours; 0.8332 g of PdCl2 and 0.8075 g of CoCl2·6H2O were accurately weighed and dissolved in 14 mL of deionized water, stirred until completely dissolved, and the prepared solution was slowly added dropwise to the activated carbon treated with the promoter. The obtained mixture was subjected to ultrasonic treatment for 2 hours, and then the mixture was dried at 120°C for 8 hours. The dried material was transferred to a tube furnace, nitrogen was introduced to replace the air, and the temperature was raised to 400°C at a rate of 10°C / min under a nitrogen atmosphere. Hydrogen was then introduced to replace the single body, and the reduction was carried out at 400°C under a hydrogen atmosphere for 3 hours. Nitrogen was then introduced again, and the temperature was allowed to cool to room temperature under a nitrogen atmosphere, thereby obtaining a 5%Pd2%Co / SiC catalyst, hereinafter referred to as catalyst 2.

[0082] (2) 5 g of catalyst 2 prepared in step (1), 20 g of 11-CUA, 120 g of 28% ammonia water, and 120 g of n-butanol were added to a 1L autoclave, the autoclave was sealed, and the air tightness was tested. After replacing the air in the reactor with nitrogen, the nitrogen in the reactor was replaced with hydrogen, the temperature was raised to 100°C, the hydrogen pressure in the reactor was increased to 3.0 MPa, and the reaction was carried out for 0.5 hours. The catalyst was recovered by hot filtration, the filtrate was cooled to crystallize, and the product 12-ADA was obtained by suction filtration and drying. The purity of 12-ADA was 98.3% by chromatographic analysis, the content of 12,12'-iminododecanedioic acid was 0.05%, the conversion of 11-CUA was 99.1%, and the selectivity of 12-ADA was 98.5%. The target product 12-ADA can be used for the synthesis of nylon 12 in subsequent steps.

[0083] Example 3

[0084] (1) 10.0000 g of silicon carbide (SiC) support was added to 50 mL of 0.05 mol / L aqueous solution of polyvinylpyrrolidone (average molecular weight of polyvinylpyrrolidone ~ 30000), soaked for 6 hours, centrifuged to remove excess aqueous solution, and the wet solid material was dried at 120°C for 8 hours; 0.5174 g of RuCl3·3H2O and 0.2682 g of CuCl2·2H2O were accurately weighed and dissolved in 12 mL of deionized water, stirred until completely dissolved, and the prepared solution was slowly added dropwise to the silicon carbide treated with the promoter, and the obtained mixture was subjected to ultrasonic treatment for 2 hours, and then the mixture was dried at 120°C for 8 hours. The dried material was transferred to a tube furnace, nitrogen was introduced to replace the air, and the temperature was raised to 400°C at a rate of 10°C / min under a nitrogen atmosphere, and then hydrogen was introduced to replace the single body, and the reduction was carried out at 400°C under a hydrogen atmosphere for 3 hours, and then nitrogen was introduced, and the temperature was naturally cooled to room temperature under a nitrogen atmosphere, thereby obtaining a 2% Ru1% Cu / SiC catalyst, hereinafter referred to as catalyst 3.

[0085] (2) 10 g of catalyst 3 prepared in step (1), 40 g of 11-CUA, 120 g of 28% ammonia water, and 120 g of n-butanol were put into a 1 L autoclave, the autoclave was sealed, and after testing the airtightness, the air in the reactor was replaced with nitrogen, and then the nitrogen in the reactor was replaced with hydrogen, the temperature was raised to 100°C, the hydrogen pressure in the reactor was increased to 3.0 MPa, and the reaction was carried out for 1 hour, then hot filtration was carried out, the catalyst was recovered, the filtrate was cooled to crystallize, and after suction filtration and drying, 40.43 g of 12-ADA product was obtained, the purity of 12-ADA was 99.1% by chromatographic analysis, the content of 12,12'-iminododecanoic acid was 0.01%, the conversion of 11-CUA was 99.8%, and the selectivity of 12-ADA was 99.5%.

[0086] The above step (2) was repeated fifteen times using the recovered catalyst, and no significant decrease in conversion and selectivity was observed. The target product 12-ADA can be used for the synthesis of nylon 12.

[0087] Example 4

[0088] (1) 10.0000 g of carbon nanotube (CNT) support was added to 100 mL of 0.5 mol / L tributyl phosphite aqueous solution, soaked for 8 hours, centrifuged to remove excess aqueous solution, and the wet solid material was dried at 120°C for 8 hours; 0.2587 g of RuCl3·3H2O and 0.0951 g of SnCl2·2H2O were accurately weighed and dissolved in 36 mL of deionized water, stirred until completely dissolved, and the prepared solution was slowly added dropwise to the CNT treated with the promoter, the obtained mixture was subjected to ultrasonic treatment for 2 hours, and then the mixture was dried at 120°C for 8 hours. The dried material was transferred to a tube furnace, nitrogen was introduced to replace the air, and the temperature was raised to 450°C at a rate of 10°C / min under a nitrogen atmosphere, and then hydrogen was introduced to replace the single body, and the reduction was carried out under a hydrogen atmosphere at 450°C for 3 hours, and then nitrogen was introduced, and the temperature was naturally cooled to room temperature under a nitrogen atmosphere, thereby obtaining a 1% Ru0.5% Sn / CNT catalyst, hereinafter referred to as catalyst 4.

[0089] (2) 10 g of catalyst 4 prepared in step (1), 40 g of 11-CUA, 140 g of 28% ammonia water, and 140 g of n-butanol were added to a 1 L autoclave, the autoclave was sealed, and after testing the airtightness, the air in the reactor was replaced with nitrogen, and then the nitrogen in the reactor was replaced with hydrogen, the temperature was raised to 100°C, the hydrogen pressure in the reactor was increased to 3.0 MPa, and the reaction was carried out for 1 hour, then hot filtration was carried out, the catalyst was recovered, the filtrate was cooled to crystallize, and after suction filtration and drying, 40.48 g of 12-ADA product was obtained, the purity of 12-ADA was 97.9% by chromatographic analysis, the content of 12,12'-iminododecanoic acid was 0.02%, the conversion rate of 11-CUA was 99.3%, and the selectivity of 12-ADA was 98.9%. The target product 12-ADA can be used for the synthesis of nylon 12 subsequently.

[0090] Example 5

[0091] (1) 10.0000 g of activated carbon (AC) support was added to 10 mL of 0.5 mol / L aqueous solution of triphenylphosphine, soaked for 8 hours, centrifuged to remove excess aqueous solution, and the wet solid material was dried at 120°C for 8 hours; 0.1579 g of Rh(NO3)3·2H2O and 0.7119 g of FeCl2·4H2O were accurately weighed and dissolved in 14 mL of deionized water, stirred until completely dissolved, and the prepared solution was slowly added dropwise to the AC treated with the promoter, the obtained mixture was subjected to ultrasonic treatment for 2 hours, and then the mixture was dried at 120°C for 8 hours. The dried material was transferred to a tube furnace, nitrogen was introduced to replace the air, and the temperature was raised to 450°C at a rate of 10°C / min under a nitrogen atmosphere, and then hydrogen was introduced to replace the single body, and the reduction was carried out at 450°C under a hydrogen atmosphere for 3 hours, and then nitrogen was introduced, and the temperature was naturally cooled to room temperature under a nitrogen atmosphere, thereby obtaining a 0.5% Rh2% Fe / AC catalyst, hereinafter referred to as catalyst 5.

[0092] (2) 5 g of catalyst 5 prepared in step (1), 20 g of 11-CUA, 140 g of 28% ammonia water, and 140 g of n-butanol were added to a 1 L autoclave, the autoclave was sealed, and after testing the airtightness, the air in the reactor was replaced with nitrogen, and then the nitrogen in the reactor was replaced with hydrogen, the temperature was raised to 100°C, the hydrogen pressure in the reactor was increased to 3.0 MPa, and the reaction was carried out for 1 hour, then hot filtration was carried out, the catalyst was recovered, the filtrate was cooled to crystallize, and after suction filtration and drying, 20.13 g of 12-ADA product was obtained, the purity of 12-ADA was 98.7% by chromatographic analysis, the content of 12,12'-iminododecanedioic acid was 0.04%, the conversion rate of 11-CUA was 99.2%, and the selectivity of 12-ADA was 98.3%. The target product 12-ADA can be used for the synthesis of nylon 12 subsequently.

[0093] Example 6

[0094] (1) 10.0000 g of activated carbon (AC) support was added to 20 mL of 0.5 mol / L polyvinyl alcohol (degree of alcoholysis > 99.5 mol%) aqueous solution, soaked for 8 hours, centrifuged to remove excess aqueous solution, and the wet solid material was dried at 120 °C for 8 hours; 0.1667 g of PdCl2 and 0.2682 g of CuCl2·2H2O were accurately weighed and dissolved in 14 mL of deionized water, stirred until completely dissolved, and the prepared solution was slowly added dropwise to the AC treated with the promoter, the obtained mixture was subjected to ultrasonic treatment for 2 hours, and then the mixture was dried at 120 °C for 8 hours. The dried material was transferred to a tube furnace, nitrogen was introduced to replace the air, and the temperature was raised to 100 °C at a rate of 10 °C / min under a nitrogen atmosphere, and then hydrogen was introduced to replace the nitrogen at 100 °C, and the reduction was carried out at 100 °C for 5 hours under a hydrogen atmosphere, and then nitrogen was introduced again, and the temperature was allowed to cool to room temperature under a nitrogen atmosphere, thereby obtaining a 1%Pd1%Cu / AC catalyst, hereinafter referred to as catalyst 6.

[0095] (2) 5 g of catalyst 6 prepared in step (1), 100 g of adiponitrile, and 100 g of anhydrous ethanol were placed in a 1 L autoclave, the autoclave was sealed, the air tightness was tested, the air in the autoclave was replaced with nitrogen, and then the nitrogen in the autoclave was replaced with hydrogen, the temperature was raised to 70 °C, the hydrogen pressure in the autoclave was increased to 3.0 MPa, and the reaction was carried out for 1 hour, the catalyst was recovered by hot filtration, and the filtrate was analyzed by chromatography, the conversion rate of adiponitrile was 90.2%, and the selectivity of hexamethylenediamine was 95.3%. The hexamethylenediamine prepared in this example can be subsequently reacted with adipic acid or adipoyl chloride to synthesize nylon-66.

[0096] Comparative Example 1

[0097] (1) 0.5174 g of RuCl3·3H2O was accurately weighed and dissolved in 14 mL of deionized water, stirred until completely dissolved, and the prepared solution was slowly added dropwise to 10.0000 g of activated carbon (AC) without any treatment, the obtained mixture was subjected to ultrasonic treatment for 2 hours, and then the mixture was dried at 120 °C for 8 hours. The dried material was transferred to a tube furnace, nitrogen was introduced to replace the air, and the temperature was raised to 350 °C at a rate of 5 °C / min under a nitrogen atmosphere, and then hydrogen was introduced to replace the nitrogen at the temperature, and the reduction was carried out at 350 °C for 3 hours under a hydrogen atmosphere, and then nitrogen was introduced again, and the temperature was allowed to cool to room temperature under a nitrogen atmosphere, thereby obtaining a 2%Ru / AC catalyst, hereinafter referred to as comparative catalyst A.

[0098] (2) Put 5 g of the comparative catalyst A prepared in step (1), 10 g of 11-CUA, 120 g of ammonia water with a concentration of 28%, and 120 g of n-butanol into a 1 L autoclave, seal the autoclave, replace the air in the autoclave with nitrogen after testing the air tightness, then replace the nitrogen in the autoclave with hydrogen, heat to 100°C, increase the hydrogen pressure in the autoclave to 3.0 MPa, react for 1 hour, filter while hot, recover the catalyst, and cool the filtrate to crystallize, and dry by suction filtration to obtain 12-ADA product 8.58 g, which is analyzed by chromatography, the purity of 12-ADA is 78.9%, the content of 12,12'-iminododecanedioic acid is 2.3%, the conversion rate of 11-CUA is 66.4%, and the selectivity of 12-ADA is 75.3%.

[0099] Comparative Example 2

[0100] (1) Put 10.0000 g of silicon carbide (SiC) carrier into 50 mL of 2.0 mol / L aqueous butanediaminetetraacetic acid solution, soak for 4 hours, centrifuge to remove excess aqueous solution, and dry the wet solid material at 120°C for 8 hours; accurately weigh 0.5174 g of RuCl3·3H2O and dissolve in 12 mL of deionized water, stir until completely dissolved, and slowly drop the prepared solution into the silicon carbide treated with the promoter drop by drop, ultrasonically treat the obtained mixture for 2 hours, and then dry the mixture at 120°C for 8 hours. Transfer the dried material to a tube furnace, replace the air with nitrogen, heat to 350°C at a heating rate of 5°C / min under a nitrogen atmosphere, then start to replace the single body with hydrogen, heat and reduce at 350°C for 5 hours under a hydrogen atmosphere, then replace with nitrogen, and naturally cool to room temperature under a nitrogen atmosphere, thereby obtaining a 2% Ru / SiC catalyst, hereinafter referred to as comparative catalyst B.

[0101] (2) Put 5 g of the comparative catalyst B prepared in step (1), 10 g of 11-CUA, 120 g of ammonia water with a content of 28%, and 120 g of n-butanol into a 1 L autoclave, seal the autoclave, replace the air in the autoclave with nitrogen after testing the air tightness, then replace the nitrogen in the autoclave with hydrogen, heat to 100°C, increase the hydrogen pressure in the autoclave to 3.0 MPa, react for 0.5 hours, filter while hot, recover the catalyst, cool the filtrate to crystallize, and dry by suction filtration to obtain 12-ADA product 9.28 g, which is analyzed by chromatography, the purity of 12-ADA is 88.9%, the content of 12,12'-iminododecanedioic acid is 0.8%, the conversion rate of 11-CUA is 84.06%, and the selectivity of 12-ADA is 89.2%.

[0102] The results of the above inventive examples and comparative examples show that the catalyst system specially designed in the present application can achieve extremely excellent conversion rate and selectivity, and the catalyst has excellent stability, and can be repeatedly used while maintaining the conversion rate and selectivity substantially unchanged.

Claims

1. A method for hydrogenation reduction of a compound containing a cyano group, the method comprising converting a cyano group (-CN) to an aminomethylene group (-CH2-NH2) by reacting the cyano group contained in the compound with hydrogen gas in the presence of a catalyst; the catalyst is prepared by a method comprising the following steps: Step 1: providing a carrier selected from at least one of activated carbon, silicon carbide, porous carbon, carbon nanotube, carbon black, fullerene, graphene, fluorescent carbon, carbon fiber, vapor deposition carbon, carbon felt, graphite felt; Step 2: treating the carrier with a promoter selected from at least one of ethylenediaminetetraacetic acid, tetramethylethylenediamine, triethanolamine, tributylphosphine, triphenylphosphine, trihexyl phosphite, tributyl phosphite, triethyl phosphite, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid to obtain a treated carrier; Step 3: impregnating the treated carrier with a solution containing a noble metal salt and a solution containing a transition metal salt, the noble metal being selected from ruthenium, rhodium, palladium, or a combination thereof, the transition metal being selected from at least one of cobalt, iron, nickel, copper, zinc, tin, bismuth to obtain a catalyst precursor; Step 4: the catalyst precursor is first heated to 300-500°C under an inert atmosphere or vacuum, and then reduced under a reducing atmosphere at a temperature of 300-500°C to obtain the catalyst; in the catalyst, the content of the promoter is 0.1-20 parts by weight, the content of the noble metal is 0.05-5 parts by weight, and the content of the transition metal is 0.1-15 parts by weight, based on 100 parts by weight of the carrier.

2. The method of claim 1, wherein, in the Step 2, the water solution of the promoter is mixed with the carrier, and the weight ratio of the promoter contained in the water solution to the carrier is 0.1-10:

1.

3. The method of claim 2, wherein, in the Step 2, the concentration of the water solution of the promoter is 0.20-3.0 moles / liter; and the volume of the water solution to the weight of the carrier is 10-1000 milliliters of solution per 100 grams of carrier.

4. The method of any one of claims 1-3, wherein, in the Step 2, the carrier is soaked in the water solution of the promoter for 0.5-12 hours, and then the carrier is separated from the water solution; in the Step 3, all the noble metal salt and all the transition metal salt are absorbed in the carrier.

5. The method of claim 1, wherein, the compound containing a cyano group has the following formula I: Formula I wherein A is selected from linear or branched C1-C16 alkylene, linear or branched halogenated C1-C16 alkylene, C3-C16 cycloalkylene, halogenated C3-C16 cycloalkylene, C6-C22 arylene, halogenated C6-C22 arylene; the hydrogenation reduction is carried out at a temperature of 80-200°C under a hydrogen pressure of 0.2-5.0 MPa for 0.2-5 hours.

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