A method for the catalytic reductive amination of aldehydes, ketones and alcohol compounds to produce primary amines

Abstract

The application discloses a method for preparing primary amine by catalytic reductive amination of aldehyde, ketone and alcohol compound, and the preparation process comprises the following steps: mixing aldehyde, ketone or alcohol compound with amine source, reducing agent, solvent and cheap metal heterogeneous catalyst in a reactor, and obtaining corresponding primary amine compound through reductive amination reaction. The preparation method provided by the application has wide application range of substrates, and can efficiently and selectively obtain corresponding primary amine through indirect or direct reductive amination process of various aldehyde, ketone and alcohol compound, meanwhile, the catalyst used has good cycle stability, and the synthesis raw material is cheap and easy to obtain, and the economic efficiency is high.

Description

Technical Field

[0001] This invention relates to the fields of heterogeneous catalysis and organic synthesis technology, specifically to a method for the catalytic reduction and amination of aldehydes, ketones and alcohols to prepare primary amines. Background Technology

[0002] Amines are an important class of organic compounds. Among them, primary amines, due to their relatively active amino functional groups, have been widely used as important chemical raw materials in the production of chemicals such as plastics, dyes, surfactants, and pharmaceuticals.

[0003] The main methods for synthesizing primary amines include: direct amination of alcohols, reductive amination of aldehydes or ketones, hydrogenation reduction of nitriles, hydrogenation reduction of nitro compounds, ammonolysis of haloalkanes, and addition of ammonia to alkenes. Among these, the reductive amination of aldehydes, ketones, and alcohols to synthesize primary amines has become a research hotspot due to its wide availability of substrates, ease of operation, and high atom economy. Based on whether the imine or imine ion intermediate is separated, the reductive amination reactions of aldehydes / ketones / alcohols are divided into direct reductive amination and indirect reductive amination. Indirect reductive amination requires multiple steps, making the entire reaction process extremely complex. Furthermore, most imine intermediates are highly unstable and difficult to separate, resulting in less than ideal yields and limited substrate availability, ultimately hindering industrial production. Therefore, from a synthetic route perspective, direct reductive amination is relatively greener, simpler, and more economical, and is more favored by researchers. However, the direct reductive amination process involves side reactions such as hydrogenation competition between the starting substrate and the imine intermediate, and condensation of the product primary amine with the starting substrate, resulting in poor selectivity for the preparation of primary amines via this route.

[0004] Catalysts used for the reductive amination of aldehydes, ketones, and alcohols are mainly classified into homogeneous catalysts and heterogeneous catalysts. While homogeneous catalysis can yield primary amines in high yields, it suffers from problems such as difficult catalyst separation, low reusability, and the need for post-treatment of the reaction solution. Heterogeneous catalysts, on the other hand, offer advantages such as easy separation and recyclability, making them highly promising for industrial production. Currently, noble metal (Ru, Rh, Pd, Pt, etc.) supported heterogeneous catalysts are widely used in the large-scale reductive amination of aldehydes, ketones, and alcohols to produce primary amines, but they still have drawbacks such as high production costs, loss and deactivation of active metal components, and low selectivity for primary amines. Therefore, more and more researchers are exploring the application of inexpensive metal heterogeneous catalysts in reductive amination. However, inexpensive metal heterogeneous catalysts are susceptible to corrosion by gases such as ammonia, leading to catalyst deactivation and decreased stability, which is detrimental to industrial applications.

[0005] Therefore, developing a heterogeneous catalytic method to achieve highly selective, highly active, and highly stable reductive amination of aldehydes / ketones / alcohols to prepare primary amines is a highly challenging and meaningful task. Summary of the Invention

[0006] To address the aforementioned shortcomings in the prior art, the present invention aims to provide a method for the catalytic reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, thereby solving the problems of high catalyst production costs, loss and poisoning of active metal components, and low selectivity and yield of primary amine products in the reductive amination reaction of aldehydes / ketones / alcohols in the prior art.

[0007] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0008] A method for preparing primary amines by catalytic reductive amination of aldehydes, ketones and alcohols is provided. The reaction substrate (aldehyde, ketone or alcohol) is mixed with an amine source, a reducing agent, a solvent and a heterogeneous catalyst in a reactor, and the corresponding primary amine compound is obtained by direct or indirect reductive amination reaction.

[0009] Furthermore, the molar ratio of reaction substrate, amine source, reducing agent, and heterogeneous catalyst is (0-2000):(0-2000):(0-2000):(0-2000).

[0010] Furthermore, the reaction substrate is at least one of aliphatic aldehydes, aliphatic ketones, aliphatic alcohols, or aldehydes, ketones, or alcohols containing benzene rings or heterocycles.

[0011] Furthermore, the amine source is at least one of ammonia water, ammonia gas, ammonium acetate, and hydroxylamine hydrochloride; the reducing agent is at least one of hydrogen gas, sodium borohydride, lithium borohydride, and potassium borohydride; and the solvent is at least one of ethanol, methanol, water, n-butanol, tetrahydrofuran, and acetonitrile.

[0012] Furthermore, the heterogeneous catalyst is a low-cost metal catalyst coated with carbon nanotubes and doped with non-metallic elements.

[0013] Furthermore, the inexpensive metal salt is at least one of ferric nitrate, ferric acetylacetonate, cobalt nitrate, cobalt acetylacetonate, cobalt acetate, nickel nitrate, nickel acetylacetonate, and nickel acetate; the doping nonmetal source is at least one of triphenylphosphine, thiourea, and boric acid.

[0014] Furthermore, the method specifically includes the following steps:

[0015] Preparation of S1 heterogeneous catalyst

[0016] One or more inexpensive metal salts are dispersed in a solvent and subjected to a solvothermal reaction to obtain inexpensive metal (or alloy) nanoparticles; then, the inexpensive metal (or alloy) nanoparticles are mixed with a nitrogen source, a carbon source, and a doped non-metallic element source, and the metal (or alloy) nanoparticles are used as templates and generation directing agents. Under argon protection, the mixture is pyrolyzed at high temperature to obtain a non-metallic element-doped carbon nanotube-coated inexpensive metal (or alloy) multiphase catalyst.

[0017] S2-catalyzed reduction amination reaction

[0018] The reaction substrate is mixed with an amine source, a reducing agent, a solvent, and a heterogeneous catalyst in a reactor, and the corresponding primary amine compound is obtained by reductive amination reaction.

[0019] Furthermore, in S1, the molar ratio of inexpensive metal or its alloy nanoparticles, nitrogen source, carbon source, and doped non-metallic element source is (0~10000):(0~10000):(0~10000):(0~10000).

[0020] Furthermore, in S1, the temperature of the solvothermal reaction is 100–350℃, and the reaction time is 1–5h; the pyrolysis temperature for preparing the catalyst by high-temperature pyrolysis is 500–1200℃, the reaction time is 1–5h, and the heating rate is 1–10℃ / min.

[0021] Furthermore, in S2, the reaction temperature is 50–200℃, the reaction time is 1–24h, and the pressure inside the reactor is 0.1–10MPa.

[0022] The beneficial effects of this invention are as follows:

[0023] (1) The method for preparing primary amines by catalytic reductive amination of aldehydes, ketones and alcohols provided by the present invention has a wide range of substrates and can be used efficiently and selectively for the indirect or direct reductive amination of various aldehydes, ketones and alcohols to prepare primary amines.

[0024] (2) The multiphase catalyst used in this invention uses inexpensive metals as active components, which helps to reduce the cost of catalyst preparation.

[0025] (3) The present invention utilizes a strategy of coating metal particles with carbon nanotubes to make the heterogeneous catalyst more stable under reaction conditions and the active components are less likely to be lost.

[0026] (4) The multiphase catalyst provided by the present invention has a carbon nanotube support with the characteristics of non-metallic element double doping. According to the different electronegativity of non-metallic elements, the electronic structure of the catalyst surface can be adjusted to control the adsorption capacity of the substrate or intermediate to the active site on the catalyst surface, thereby improving the selectivity of the catalyst to the product.

[0027] (5) By adjusting the composition of metal particles, the present invention can adjust their corrosion resistance and regulate their electronic structure, thereby optimizing their reductive amination activity and stability.

[0028] (6) The catalyst obtained by the present invention is a heterogeneous catalyst, which is easy to separate the reaction products from the catalyst and to recycle the catalyst multiple times, and has the potential for large-scale production. Attached Figure Description

[0029] Figure 1 This is a transmission electron microscope image of the metal nanoparticles prepared in Example 1;

[0030] Figure 2 The images shown are transmission electron microscope (TEM) images of the heterogeneous catalyst prepared in Example 1; where a, b, and c are TEM images of inexpensive metal catalysts coated with non-metallic element-doped carbon nanotubes.

[0031] Figure 3 The X-ray photoelectron spectrum (full spectrum) of the heterogeneous catalyst prepared in Example 1 is shown below.

[0032] Figure 4 The X-ray photoelectron spectra (fine spectra) of the Ni 2p, N 1s and B1s core levels of the heterogeneous catalyst prepared in Example 1 are shown.

[0033] Figure 5 The product 2,5-furandimethylamine prepared in Example 1 1 H NMR spectrum;

[0034] Figure 6 The product 2,5-furandimethylamine prepared in Example 1 13 C NMR spectrum;

[0035] Figure 7 The graph shows the cyclic stability test performance in Example 31. Detailed Implementation

[0036] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0037] Example 1

[0038] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0039] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0040] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 95.4%).

[0041] Example 2

[0042] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0043] S1. Add 1 part ferric nitrate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, allow it to cool naturally to room temperature, and add 40 parts ethanol to precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain iron nanoparticles. Then, disperse 2 parts iron nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove the ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water sequentially, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Fe-N,B-CNT.

[0044] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 73.0%).

[0045] Example 3

[0046] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0047] S1. Add 1 part nickel acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, allow it to cool naturally to room temperature, and add 40 parts ethanol to precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain nickel nanoparticles. Next, disperse 2 parts nickel nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove the ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder sequentially with dilute hydrochloric acid and deionized water, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Ni-N,B-CNT.

[0048] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140℃ for 2 h to obtain 2,5-furandimethylamine (yield 81.2%).

[0049] Example 4

[0050] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0051] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, and add 40 parts ethanol to precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts thiourea in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,S-CNT.

[0052] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 89.4%).

[0053] Example 5

[0054] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0055] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, and add 40 parts ethanol to precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts triphenylphosphine in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,P-CNT.

[0056] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 96.0%).

[0057] Example 6

[0058] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0059] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0060] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonium acetate and 1 part of catalyst in 100 parts of ethanol, and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 90.3%).

[0061] Example 7

[0062] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0063] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0064] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of hydroxylamine hydrochloride and 1 part of catalyst in 100 parts of ethanol, and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 91.7%).

[0065] Example 8

[0066] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0067] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0068] S2. Disperse 1 part of 2,5-furandicarboxaldehyde and 1 part of catalyst in 100 parts of ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with 0.5 MPa of ammonia and then purge with hydrogen to 3.5 MPa. Seal the vessel and react at 140 °C for 2 h to obtain 2,5-furandimethylamine (yield 95.2%).

[0069] Example 9

[0070] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0071] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0072] S2. Disperse 1 part of 2,5-furandicarboxaldehyde and 1 part of catalyst in 100 parts of ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with 0.5 MPa of ammonia and then purge with hydrogen to 3.5 MPa. Seal the vessel and react at 180°C for 1 h to obtain 2,5-furandimethylamine (yield 93.9%).

[0073] Example 10

[0074] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0075] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0076] S2. Disperse 1 part of 2,5-furandicarboxaldehyde and 1 part of catalyst in 100 parts of ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with 0.5 MPa of ammonia and then purge with hydrogen to 3.5 MPa. Seal the vessel and react at 100°C for 5 h to obtain 2,5-furandimethylamine (yield 95.0%).

[0077] Example 11

[0078] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0079] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0080] S2. Disperse 1 part of 2,5-furandicarboxaldehyde and 1 part of catalyst in 100 parts of ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with 0.5 MPa of ammonia and then purge with hydrogen to 3.5 MPa. Seal the vessel and react at 60°C for 10 h to obtain 2,5-furandimethylamine (yield 76.7%).

[0081] Example 12

[0082] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0083] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0084] S2. Disperse 1 part terephthalaldehyde, 10 parts ammonia and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain terephthalic acid (yield 96.8%).

[0085] Example 13

[0086] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0087] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0088] S2. Disperse 1 part 5-hydroxymethylfurfural, 10 parts ammonia and 1 part catalyst in 100 parts ethanol and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140 °C for 2 h to obtain 2,5-furandimethylamine (yield 96.7%).

[0089] Example 14

[0090] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0091] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0092] S2. Disperse 1 part benzaldehyde, 10 parts ammonia and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 2.0 MPa, then seal and react at 140°C for 3 hours to obtain benzylamine (yield 92.6%).

[0093] Example 15

[0094] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0095] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0096] S2. Disperse 1 part p-methoxybenzaldehyde, 10 parts ammonia and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 5.0 MPa, then seal and react at 140°C for 1.5 h to obtain p-methoxybenzylamine (yield 96.7%).

[0097] Example 16

[0098] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0099] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0100] S2. Disperse 1 part p-methylbenzaldehyde, 10 parts ammonia and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain p-methylbenzylamine (yield 92.5%).

[0101] Example 17

[0102] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0103] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0104] S2. Disperse 1 part o-methylbenzaldehyde, 10 parts ammonia water and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain o-methylbenzylamine (yield 90.2%).

[0105] Example 18

[0106] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0107] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0108] S2. Disperse 1 part o-fluorobenzaldehyde, 10 parts ammonia water and 1 part catalyst in 100 parts ethanol and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 5.0 MPa, then seal and react at 160℃ for 3 h to obtain o-fluorobenzylamine (yield 96.1%).

[0109] Example 19

[0110] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0111] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0112] S2. Disperse 1 part m-chlorobenzaldehyde, 10 parts ammonia and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 180°C for 3 hours to obtain m-chlorobenzylamine (yield 95.8%).

[0113] Example 20

[0114] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0115] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0116] S2. Disperse 1 part p-bromobenzaldehyde, 10 parts ammonia water and 1 part catalyst in 100 parts ethanol and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 160℃ for 5 h to obtain p-bromobenzylamine (yield 92.5%).

[0117] Example 21

[0118] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0119] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0120] S2. Disperse 1 part m-trifluoromethylbenzaldehyde, 10 parts ammonia water and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 180°C for 3 hours to obtain m-trifluoromethylbenzylamine (yield 91.8%).

[0121] Example 22

[0122] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0123] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0124] S2. Disperse 1 part of furfural, 10 parts of ammonia and 1 part of catalyst in 100 parts of ethanol and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 3.5 MPa, then seal and react at 180°C for 3 hours to obtain furfurylamine (yield 90.0%).

[0125] Example 23

[0126] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0127] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0128] S2. Disperse 1 part 4-pyridinecarboxaldehyde, 10 parts ammonia water and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140 °C for 10 h to obtain 4-aminomethylpyridine (yield 90.2%).

[0129] Example 24

[0130] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0131] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0132] S2. Disperse 1 part 2-thiophene formaldehyde, 10 parts ammonia water and 1 part catalyst in 100 parts ethanol and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140℃ for 2 h to obtain 2-aminomethylthiophene (yield 85.9%).

[0133] Example 25

[0134] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0135] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0136] S2. Disperse 1 part acetophenone, 10 parts ammonia and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 160°C for 20 h to obtain phenethylamine (yield 85.5%).

[0137] Example 26

[0138] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0139] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0140] S2. Disperse 1 part of 1,4-cyclohexanedione, 10 parts of ammonia and 1 part of catalyst in 100 parts of ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140 °C for 2 h to obtain 1,4-cyclohexanediamine (yield 83.4%).

[0141] Example 27

[0142] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0143] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0144] S2. Disperse 1 part benzyl alcohol, 10 parts ammonia water and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain benzylamine (yield 93.5%).

[0145] Example 28

[0146] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0147] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT.

[0148] S2. Disperse 1 part 1-phenylethanol, 10 parts ammonia and 1 part catalyst in 100 parts ethanol and add them to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain phenylethylamine (yield 71.4%).

[0149] Example 29

[0150] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0151] S1. Add 1 part cobalt acetate and 5 parts nickel acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, and add 40 parts ethanol to precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain nickel-cobalt alloy nanoparticles. Then, disperse 2 parts nickel-cobalt alloy nanoparticles, 600 parts melamine and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as NiCo-N,B-CNT.

[0152] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 94.5%).

[0153] Example 30

[0154] This embodiment provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0155] S1. Add 1 part cobalt acetate and 5 parts ferric nitrate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, and add 40 parts ethanol to precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain iron-cobalt alloy nanoparticles. Then, disperse 2 parts iron-cobalt alloy nanoparticles, 600 parts melamine and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as FeCo-N,B-CNT.

[0156] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 90.2%).

[0157] Example 31 (Cyclic Stability Test)

[0158] This embodiment provides a method for the direct reductive amination of aldehydes, ketones and alcohols to prepare primary amines, and the steps are exactly the same as those in Example 1.

[0159] After one complete catalytic cycle as described in Example 1, the reaction solution was centrifuged to obtain a solid catalyst, which was then washed several times with water and dried under vacuum at 70°C. The dried catalyst was then reused. Its catalytic activity and stability were tested, and the number of cycles was counted.

[0160] Comparative Example 1

[0161] This comparative example provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0162] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, allow it to cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles and 600 parts melamine in 40 parts ethanol, stir and mix evenly, remove the ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water successively, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N-CNT.

[0163] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 68.4%).

[0164] Comparative Example 2

[0165] This comparative example provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0166] S1. Add 1 part nickel acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, allow it to cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain nickel nanoparticles. Then, disperse 2 parts nickel nanoparticles and 600 parts melamine in 40 parts ethanol, stir and mix evenly, remove the ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Ni-N-CNT.

[0167] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 42.6%).

[0168] Comparative Example 3

[0169] This comparative example provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0170] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir to disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, allow it to cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Disperse 2 parts cobalt nanoparticles and 600 parts Ketjen black powder in 40 parts ethanol, stir to mix, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder sequentially with dilute hydrochloric acid and deionized water, then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co@C.

[0171] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 38.0%).

[0172] Comparative Example 4

[0173] This comparative example provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0174] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, and add 40 parts ethanol to precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts Ketjen black powder, 50 parts urea and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co@N,BC.

[0175] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 29.3%).

[0176] Comparative Example 5

[0177] This comparative example provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0178] S1. Add 1 part cobalt nitrate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT-NO.

[0179] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 95.3%).

[0180] Comparative Example 6

[0181] This comparative example provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0182] S1. Add 1 part cobalt nitrate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles, 600 parts melamine, and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 800℃ for 2 hours under an argon atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water sequentially, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-N,B-CNT-acac.

[0183] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 93.8%).

[0184] Comparative Example 7

[0185] This comparative example provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0186] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles and 10 parts thiourea in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 1000℃ for 2 hours under a methane atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-S-CNT.

[0187] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 27.3%).

[0188] Comparative Example 8

[0189] This comparative example provides a method for the direct reductive amination of aldehydes, ketones, and alcohols to prepare primary amines, comprising the following steps:

[0190] S1. Add 1 part cobalt acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300℃ and maintain for 1 hour; then, allow it to cool naturally to room temperature, and add 40 parts ethanol to precipitate. Centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles. Then, disperse 2 parts cobalt nanoparticles and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove the ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, and pyrolyze at 1000℃ for 2 hours under a methane atmosphere at a heating rate of 2℃ / min. After naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water successively, and then dry it in a vacuum drying oven at 70℃ to obtain the catalyst, denoted as Co-B-CNT.

[0191] S2. Disperse 1 part of 2,5-furandicarboxaldehyde, 10 parts of ammonia water and 1 part of catalyst in 100 parts of ethanol, and add it to the reaction vessel. After replacing the gas in the vessel with nitrogen, purge with hydrogen to 4.0 MPa, then seal and react at 140°C for 2 hours to obtain 2,5-furandimethylamine (yield 35.6%).

[0192] Test case

[0193] 1. TEM image of metal nanoparticles

[0194] from Figure 1 It can be seen that the morphology of the metal nanoparticles is relatively uniform, with an average particle size of about 29.1 nm.

[0195] 2. TEM image of the catalyst

[0196] Depend on Figure 2 a- Figure 2 As shown in b, the nanotubes in the microstructure of this catalyst tightly encapsulate the metal particles, preventing the metal particles from sintering or agglomerating during high-temperature calcination. Thus, the carbon nanotube encapsulation also plays a role in dispersing the active sites of the metal. Figure 2 The high-resolution transmission electron microscope image shows the lattice fringes of the coated metal particles, with crystal planes having interplanar spacings of 0.20 and 0.17 nm, corresponding to the (111) and (200) crystal planes of cobalt, respectively, proving that the structure of the metal nanoparticles did not change significantly during the high-temperature pyrolysis process.

[0197] 3. XPS spectrum

[0198] Depend on Figures 3-4 It can be seen that Ni(0) and Ni(II) exist on the surface of the Ni-N,B-CNT catalyst. The presence of Ni(0) can be attributed to the presence of metallic nickel nanoparticles, while the presence of Ni(II) can be attributed to the oxidation of metallic nickel. At the same time, the presence of non-metallic elements N and B can be clearly seen in its XPS narrow spectrum, indicating the success of non-metallic element dual doping.

[0199] 4. Efficiency of Reduction Amination of Non-metallic Element-Doped Carbon Nanotubes Coated with Inexpensive Metal (or its Alloy) Catalysts

[0200] Table 1. Comparison of Reduction Amination Performance of Different Types of Carbon-Coated Metal Catalysts

[0201]

[0202]

[0203] Table 1 compares the catalytic efficiency of different types of carbon-coated metal catalysts in the direct reduction amination reaction of 2,5-furandicarboxaldehyde. Under the same reaction conditions, the catalytic performance of the non-metallic element-doped carbon nanotube-coated metal catalyst (Examples 1-5) for the direct reduction amination of 2,5-furandicarboxaldehyde to 2,5-furandimethylamine is significantly higher than that of the single nitrogen-doped carbon nanotube-coated metal catalyst (Comparative Examples 1-4). This is because the multiple non-metallic element doping sites can not only adjust the electronic structure of the catalyst surface but also regulate the adsorption and desorption rates of reactants or reaction intermediates at the catalyst surface sites, thereby improving the activity and selectivity of the catalytic reaction. Moreover, the single nitrogen doping (Comparative Examples 1-2) shows higher activity and yield in the catalytic reduction amination to primary amines compared to the single doping of elements such as S and B (Comparative Examples 7-8). Furthermore, the catalytic effect of the carbon nanotube-coated metal catalyst (Examples 1-5 and Comparative Examples 1-2) is also much higher than that of the ordinary carbon-coated metal catalyst (Comparative Examples 3-4), which may be attributed to the special morphology of the carbon nanotubes. Meanwhile, among inexpensive metals, cobalt-based catalysts exhibit the best performance, and heterogeneous catalysts prepared based on different cobalt salt precursors can achieve reductive amination reactions with high efficiency and selectivity (Example 1 and Comparative Examples 5-6). Therefore, in order to improve the catalytic reductive amination activity of other inexpensive metals, this invention also prepared cobalt-containing alloy heterogeneous catalysts for reductive amination experiments (Examples 29-30). Based on the original Ni and Fe-based heterogeneous catalysts, the introduction of Co metal greatly enhanced their catalytic activity.

[0204] 5. Cyclic stability test

[0205] Depend on Figure 7 As can be seen, with the increase of the number of cycles, the primary amine yield of each cycle test is greater than 90%, indicating that the catalyst and catalytic method used in this invention have relatively ideal stability to a certain extent.

[0206] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0207] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing primary amines by catalytic reductive amination of 2,5-furandicarboxaldehyde, characterized in that, The reaction substrate, amine source, reducing agent, solvent, and heterogeneous catalyst are mixed in a reactor and reacted at a reaction temperature of 50-200℃ and a reactor pressure of 0.1-10MPa for 1-24h to obtain the corresponding primary amine compound 2,5-furandimethylamine. The reaction substrate is selected from 2,5-furandicarboxaldehyde; The amine source is selected from ammonia water, ammonia gas, ammonium acetate, and hydroxylamine hydrochloride; The reducing agent is hydrogen gas; The solvent is ethanol; The heterogeneous catalyst is prepared by the following method: Add 1 part cobalt acetate to 10 parts oleylamine, stir to disperse evenly, then heat the resulting solution to 300 °C and maintain for 1 h; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate; centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles; then disperse 2 parts cobalt nanoparticles, 600 parts melamine and 10 parts boric acid in 40 parts ethanol, stir to mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, pyrolyze at 800 °C for 2 h under an argon atmosphere, with a heating rate of 2 °C / min, and after naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70 °C to obtain the catalyst.

2. A method for preparing primary amines by catalytic reduction amination of 2,5-furandicarboxaldehyde, characterized in that, The reaction substrate, amine source, reducing agent, solvent, and heterogeneous catalyst are mixed in a reactor and reacted at a reaction temperature of 50-200℃ and a reactor pressure of 0.1-10MPa for 1-24h to obtain the corresponding primary amine compound 2,5-furandimethylamine. The reaction substrate is selected from 2,5-furandicarboxaldehyde; The amine source is selected from ammonia water, ammonia gas, ammonium acetate, and hydroxylamine hydrochloride; The reducing agent is hydrogen gas; The solvent is ethanol; The heterogeneous catalyst is prepared by the following method: Add 1 part ferric nitrate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300 °C and maintain for 1 h; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate; centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain iron nanoparticles; then disperse 2 parts iron nanoparticles, 600 parts melamine and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, pyrolyze at 800 °C for 2 h under an argon atmosphere, with a heating rate of 2 °C / min, and after naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70 °C to obtain the catalyst.

3. A method for preparing primary amines by catalytic reduction amination of 2,5-furandicarboxaldehyde, characterized in that, The reaction substrate, amine source, reducing agent, solvent, and heterogeneous catalyst are mixed in a reactor and reacted at a reaction temperature of 50-200℃ and a reactor pressure of 0.1-10MPa for 1-24h to obtain the corresponding primary amine compound 2,5-furandimethylamine. The reaction substrate is selected from 2,5-furandicarboxaldehyde; The amine source is selected from ammonia water, ammonia gas, ammonium acetate, and hydroxylamine hydrochloride; The reducing agent is hydrogen gas; The solvent is ethanol; The heterogeneous catalyst is prepared by the following method: Add 1 part nickel acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300 °C and maintain for 1 h; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate; centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain nickel nanoparticles; then disperse 2 parts nickel nanoparticles, 600 parts melamine and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, pyrolyze at 800 °C for 2 h under an argon atmosphere, with a heating rate of 2 °C / min, and after naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70 °C to obtain the catalyst.

4. A method for preparing primary amines by catalytic reductive amination of 2,5-furandicarboxaldehyde, characterized in that, The reaction substrate, amine source, reducing agent, solvent, and heterogeneous catalyst are mixed in a reactor and reacted at a reaction temperature of 50-200℃ and a reactor pressure of 0.1-10MPa for 1-24h to obtain the corresponding primary amine compound 2,5-furandimethylamine. The reaction substrate is selected from 2,5-furandicarboxaldehyde; The amine source is selected from ammonia water, ammonia gas, ammonium acetate, and hydroxylamine hydrochloride; The reducing agent is hydrogen gas; The solvent is ethanol; The heterogeneous catalyst is prepared by the following method: Add 1 part cobalt acetate to 10 parts oleylamine, stir to disperse evenly, then heat the resulting solution to 300 °C and maintain for 1 h; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate; centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles; then disperse 2 parts cobalt nanoparticles, 600 parts melamine and 10 parts thiourea in 40 parts ethanol, stir to mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, pyrolyze at 800 °C for 2 h under an argon atmosphere, with a heating rate of 2 °C / min, and after naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70 °C to obtain the catalyst.

5. A method for preparing primary amines by catalytic reductive amination of 2,5-furandicarboxaldehyde, characterized in that, The reaction substrate, amine source, reducing agent, solvent, and heterogeneous catalyst are mixed in a reactor and reacted at a reaction temperature of 50-200℃ and a reactor pressure of 0.1-10MPa for 1-24h to obtain the corresponding primary amine compound 2,5-furandimethylamine. The reaction substrate is selected from 2,5-furandicarboxaldehyde; The amine source is selected from ammonia water, ammonia gas, ammonium acetate, and hydroxylamine hydrochloride; The reducing agent is hydrogen gas; The solvent is ethanol; The heterogeneous catalyst is prepared by the following method: Add 1 part cobalt acetate to 10 parts oleylamine, stir to disperse evenly, then heat the resulting solution to 300 °C and maintain for 1 h; then, cool naturally to room temperature, add 40 parts ethanol, and precipitate out; centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain cobalt nanoparticles; then disperse 2 parts cobalt nanoparticles, 600 parts melamine and 10 parts triphenylphosphine in 40 parts ethanol, stir to mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, pyrolyze at 800 °C for 2 h under an argon atmosphere, with a heating rate of 2 °C / min, and after naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70 °C to obtain the catalyst.

6. A method for preparing primary amines by catalytic reduction amination of 2,5-furandicarboxaldehyde, characterized in that, The reaction substrate, amine source, reducing agent, solvent, and heterogeneous catalyst are mixed in a reactor and reacted at a reaction temperature of 50-200℃ and a reactor pressure of 0.1-10MPa for 1-24h to obtain the corresponding primary amine compound 2,5-furandimethylamine. The reaction substrate is selected from 2,5-furandicarboxaldehyde; The amine source is selected from ammonia water, ammonia gas, ammonium acetate, and hydroxylamine hydrochloride; The reducing agent is hydrogen gas; The solvent is ethanol; The heterogeneous catalyst is prepared by the following method: Add 1 part cobalt acetate and 5 parts nickel acetate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300°C and maintain for 1 h; then cool naturally to room temperature, add 40 parts ethanol to precipitate, centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain nickel-cobalt alloy nanoparticles; then disperse 2 parts nickel-cobalt alloy nanoparticles, 600 parts melamine and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, pyrolyze at 800 °C for 2 h under argon atmosphere, heating rate is 2 °C / min, after naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry in a vacuum drying oven at 70 °C to obtain the catalyst.

7. A method for preparing primary amines by catalytic reduction amination of 2,5-furandicarboxaldehyde, characterized in that, The reaction substrate, amine source, reducing agent, solvent, and heterogeneous catalyst are mixed in a reactor and reacted at a reaction temperature of 50-200℃ and a reactor pressure of 0.1-10MPa for 1-24h to obtain the corresponding primary amine compound 2,5-furandimethylamine. The reaction substrate is selected from 2,5-furandicarboxaldehyde; The amine source is selected from ammonia water, ammonia gas, ammonium acetate, and hydroxylamine hydrochloride; The reducing agent is hydrogen gas; The solvent is ethanol; The heterogeneous catalyst is prepared by the following method: Add 1 part cobalt acetate and 5 parts ferric nitrate to 10 parts oleylamine, stir and disperse evenly, then heat the resulting solution to 300°C and maintain for 1 h; then cool naturally to room temperature, add 40 parts ethanol, and precipitate; centrifuge, wash the precipitate with cyclohexane, and then vacuum dry to obtain iron-cobalt alloy nanoparticles; then disperse 2 parts iron-cobalt alloy nanoparticles, 600 parts melamine and 10 parts boric acid in 40 parts ethanol, stir and mix evenly, remove ethanol by rotary evaporation, grind and mix the resulting powder, place it in a tube furnace, pyrolyze at 800 °C for 2 h under an argon atmosphere, with a heating rate of 2 °C / min, and after naturally cooling to room temperature, wash the resulting powder with dilute hydrochloric acid and deionized water in sequence, and then dry it in a vacuum drying oven at 70 °C to obtain the catalyst.

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