A method for preparing lignin-based aliphatic cyclic diamines by hydrogenating and aminating lignin-based aromatic diphenols

Abstract

The present invention belongs to the field of high-quality utilization of biomass, and relates to a method for preparing lignin-based aliphatic cyclic diamines by hydrogenation amination of lignin-based aromatic diphenols. The present invention uses lignin-based aromatic diphenols as raw materials, ammonia as a gas source, and carries out a hydrogenation amination reaction in a reaction solvent under the action of a nickel metal catalyst loaded on biochar and a hydrogen atmosphere to prepare lignin-based aliphatic cyclic diamines; wherein the nickel metal catalyst loaded on biochar includes a boron- and nitrogen-doped biochar-loaded molybdenum sulfide carrier and an effective active ingredient loaded on the boron- and nitrogen-doped biochar-loaded molybdenum sulfide carrier; the effective active ingredient is nickel metal. The lignin-based aliphatic cyclic diamines prepared by the present invention are precursors for the production of bio-based polymer materials, and have very high economic value.

Description

Technical Field

[0001] The invention belongs to the field of high-quality utilization of biomass and relates to a method for preparing lignin-based aliphatic cyclic diamines through hydrogenation amination of lignin-based aromatic diphenols. Background Art

[0002] Biomass, as a renewable energy source with abundant reserves, is crucial for the future production of green biofuels and chemicals. Lignin is the second most abundant component in the cell walls of agricultural and forestry residues after cellulose, and its high-value conversion is an important step in realizing the biorefining production of agricultural and forestry residues. The current pulp and paper industry mainly uses cellulose and hemicellulose, producing a large amount of industrial lignin, which is incinerated or discarded as cheap fuel. The conversion and utilization of lignin is of great significance to the biomass-based chemical, energy and material industries.

[0003] Among them, bio-based materials are the fruits of the integration and innovation of biotechnology and chemical industry, and the coupled development of biochemical industry and traditional chemical industry, which will help reduce the dependence of petrochemical industry on fossil raw materials and reduce the safety risks of production process. Using the structural characteristics of biomass itself to construct non-traditional polymer building blocks and scaffolds, it can be used to produce new bio-based sustainable materials with novel structures and different application functions, thereby expanding the application field of classic polymers. Aromatic amine-derived polymers have higher thermomechanical properties than flexible long-chain aliphatic amines. Among them, the representative compounds, monocyclic or polycyclic diamines, can be used directly or through derivatization to prepare various bio-based high-performance materials.

[0004] Non-precious metal catalysts are cheaper than precious metal catalysts and have also shown very good activity in reports on hydrogenation amination. Among transition metals, Ni has the lowest cost and strong activation ability for H2 / NH3. Nickel is currently considered to be the most promising active metal and can be used to catalyze the high-value utilization of biomass raw materials by hydrogenation amination. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing lignin-based aliphatic cyclic diamines by hydrogenation amination of lignin-based aromatic diphenols in view of the deficiencies of the prior art, and to use biomass-based raw materials to modify a catalyst loaded with Ni metal, so as to prepare lignin-based aliphatic cyclic diamine compounds by hydrogenation amination of lignin-based diphenols. The present invention utilizes biomass-based raw materials for carbonization treatment to obtain carbon materials, which has the advantages of low cost and a wide source of raw materials, and then is modified by doping B and N elements, which can well interact with active metals to improve the hydrogenation amination activity of the catalyst.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] The invention discloses a method for preparing lignin-based aliphatic cyclic diamines by hydrogenation amination of lignin-based aromatic diphenols, wherein lignin-based aromatic diphenols are used as raw materials, ammonia is used as a gas source, and a hydrogenation amination reaction is carried out in a reaction solvent under the action of a nickel metal catalyst supported by biochar and in a hydrogen atmosphere to prepare lignin-based aliphatic cyclic diamines;

[0008] The biochar-loaded nickel metal catalyst comprises a boron- and nitrogen-doped biochar-loaded molybdenum sulfide carrier and an effective active component loaded on the boron- and nitrogen-doped biochar-loaded molybdenum sulfide carrier; the effective active component is nickel metal.

[0009] In some embodiments,

[0010] When the lignin-based aromatic diphenol is selected from The prepared lignin-based aliphatic cyclic diamine is ;

[0011] When the lignin-based aromatic diphenol is selected from The prepared lignin-based aliphatic cyclic diamine is ;

[0012] When the lignin-based aromatic diphenol is selected from The prepared lignin-based aliphatic cyclic diamine is ;

[0013] When the lignin-based aromatic diphenol is selected from The prepared lignin-based aliphatic cyclic diamine is .

[0014] In some embodiments, the reaction solvent is any one or a combination of methanol, isopropanol and tert-amyl alcohol; the mass ratio of the lignin-based aromatic diphenol to the nickel in the biochar-loaded nickel metal catalyst is 5:1~200:1.

[0015] There is no special requirement for the amount of the reaction solvent, as long as the raw materials are evenly dispersed.

[0016] In some embodiments, preferably, the reaction solvent is tert-amyl alcohol; the mass ratio of the lignin-based aromatic diphenol to the nickel in the biochar-loaded nickel metal catalyst is 5:1~100:1, further preferably 10:1~100:1, and further preferably 50:1.

[0017] In some embodiments, during the hydrogenation amination reaction, the pressure of ammonia is 0.5-2.0 MPa, the pressure of hydrogen is 1.0-10.0 MPa, the reaction temperature is 150-200° C., and the reaction time is 15.0-35.0 h.

[0018] In some embodiments, preferably, during the hydrogenation amination reaction, the pressure of ammonia is 0.5-1.0 MPa, more preferably 0.7 MPa.

[0019] In some embodiments, preferably, during the hydrogenation amination reaction, the pressure of hydrogen is 3.0-8.0 MPa.

[0020] In some embodiments, preferably, during the hydroamination reaction, the reaction temperature is 170° C. and the reaction time is 15.0 to 30.0 h.

[0021] In some embodiments, the biochar-supported nickel metal catalyst is prepared according to the following steps:

[0022] (1) mixing sodium alginate with boric acid, sulfur-containing amino acid, molybdate, lignin sulfonate, and a first solvent, and stirring to obtain a gel analog; hydrothermally carbonizing the gel analog to obtain a hydrothermal carbon sample; drying the hydrothermal carbon sample, calcining, washing, and drying to obtain a boron- and nitrogen-doped biochar-loaded molybdenum sulfide carrier;

[0023] (2) The boron and nitrogen-doped biochar-loaded molybdenum sulfide carrier obtained in step (1) is mixed with a second solvent and a nickel precursor, and stirred to obtain a catalyst precursor; the catalyst precursor is dried to obtain a biochar-loaded nickel metal catalyst.

[0024] In some embodiments, the sulfur-containing amino acid is any one of cysteine ​​and cystine or a combination of both; the molybdate is any one of sodium molybdate and ammonium molybdate or a combination of both; the lignin sulfonate is any one of calcium lignin sulfonate and sodium lignin sulfonate or a combination of both; the first solvent is water; the second solvent is water; the nickel precursor is any one of nickel chloride, nickel sulfate, nickel nitrite and nickel nitrate or a combination of both.

[0025] In some embodiments, preferably, the sulfur-containing amino acid is cysteine; the molybdate is sodium molybdate; the lignin sulfonate is calcium lignin sulfonate; the first solvent is water; the second solvent is water; and the nickel precursor is nickel nitrate.

[0026] There is no special requirement for the amount of the first solvent, as long as the raw materials are evenly dispersed; there is no special requirement for the amount of the second solvent, as long as the raw materials are evenly dispersed.

[0027] In some embodiments, in step (1), the mass ratio of sodium alginate to boric acid, sulfur-containing amino acid, molybdate, and lignin sulfonate is 1.0-3.0: 6.0-10.0: 1.0-3.0: 1.0-2.5: 1.0-4.0.

[0028] In some embodiments, preferably, in step (1), the mass ratio of sodium alginate to boric acid, sulfur-containing amino acid, molybdate, and lignin sulfonate is 1.0:8.0:2.0:1.5:2.0.

[0029] In some embodiments, in step (1), the stirring is carried out at room temperature for 8 to 16 h; the hydrothermal carbonization is carried out at a carbonization temperature of 180 to 220 °C for 8 to 16 h; and the calcination is carried out under inert gas protection at 700 to 900 °C for 1 to 4 h.

[0030] In some embodiments, preferably, in step (1), the stirring is carried out at room temperature for 12 h; the hydrothermal carbonization is carried out at a carbonization temperature of 220 °C for 12 h; and the calcination is carried out under inert gas protection at 800 °C for 2 h.

[0031] Wherein, in step (1), the drying is carried out at 60-100°C for 12-30 hours.

[0032] Wherein, in step (1), the calcination is carried out under the protection of an inert gas, and the inert gas is preferably nitrogen, and the flow rate of the nitrogen is 30-60 mL / min.

[0033] Wherein, in step (1), the washing is preferably carried out using water and ethanol.

[0034] In some embodiments, in step (2), the mass of nickel in the nickel precursor accounts for 0.5% to 10% of the mass of the boron- and nitrogen-doped biochar-loaded molybdenum sulfide carrier; and the stirring is carried out at room temperature for 8 to 24 h.

[0035] In some embodiments, preferably, in step (2), the mass of nickel in the nickel precursor accounts for 1.0% of the mass of the boron- and nitrogen-doped biochar-loaded molybdenum sulfide carrier; and the stirring is carried out at room temperature for 12 h.

[0036] Wherein, in step (2), the drying is carried out at 60-100°C for 12-30 hours.

[0037] In some embodiments, the biochar-supported nickel metal catalyst needs to be reduced before use. Specifically, the biochar-supported nickel metal catalyst is reduced at 400-550° C. in a hydrogen environment for 2-4 h.

[0038] In some embodiments, preferably, the biochar-supported nickel metal catalyst needs to be reduced before use, specifically: the biochar-supported nickel metal catalyst is reduced at 500° C. in a hydrogen environment for 3 h.

[0039] Wherein, the flow rate of the hydrogen is 50~100 mL / min.

[0040] Beneficial effects:

[0041] (1) The present invention modifies biocarbon materials by doping B and N heteroatoms, and successfully constructs vertically arranged MoS2 nanosheets on N and B doped carbon nanosheets by simple "hydrothermal-carbonization" to obtain MoS2@BNC composite materials. Then a small amount of Ni metal is loaded on the MoS2@BNC composite material by a simple impregnation method. The synergistic effect of the prepared vertically arranged MoS2 and N and B doped sheet carbon materials can well load and regulate metal Ni, enhance the interaction between the carrier and metal Ni, and apply it to the catalytic reaction of lignin-based diphenol hydrogenation amination to prepare lignin-based diamine platform compounds. The catalyst has high conversion efficiency and has broad application potential in the fields of energy chemical industry, fine chemical industry and petrochemical industry.

[0042] (2) The lignin-based aliphatic cyclic diamine prepared by the present invention is a precursor for producing bio-based polymer materials and has very high economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0044] Figure 1 HR-TEM image of the reduced biochar-supported nickel metal catalyst prepared in Example 1.

[0045] Figure 2 This is the TEM mapping image of the reduced biochar-supported nickel metal catalyst prepared in Example 1.

[0046] Figure 3 This is the GC-MS chart of compound 1 (4-propylcatechol) prepared in Example 2.

[0047] Figure 4 This is the GC-MS chart of compound 2 (2,2'-methylenebis(4-propylphenol)) prepared in Example 3.

[0048] Figure 5 This is the GC-MS chart of compound 3 (2-[(2-hydroxy-3-methoxy-5-propylphenyl)methyl]-6-methoxy-4-propylphenol) prepared in Example 4.

[0049] Figure 6 This is the GC-MS chart of compound 4 (3,3'-dimethoxy-5,5'-dipropylbiphenyl-2,2'-diol) prepared in Example 5. DETAILED DESCRIPTION

[0050] The present invention can be better understood according to the following examples. However, it is easy for those skilled in the art to understand that the contents described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0051] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0052] The conversion rate of the substrate and the selectivity of the product in the embodiment of the present invention are detected by gas chromatography-mass spectrometry, and the detection conditions are the same, and the specific detection conditions are: chromatographic column: HP-5MS (30 m × 0.25 mm × 0.25 μm); carrier gas: high-purity helium (99.999%); flow rate 1.5 mL / min; non-split injection; the detection temperature program parameters of GC-MS (Agilent 7890B GC / 5977MS) are set as follows: injection temperature 250°C, column box starting temperature 50°C maintained for 1 min, 20°C / min temperature increase to 280°C, maintained for 4 min. Electron ionization (EI=70Ev) mass spectra in the range of 35~700 (m / z) were recorded in full scan mode. The detected compounds were identified based on the NIST database.

[0053] Example 1: Synthesis of Biochar-Supported Nickel Metal Catalyst

[0054] (1) 1 g of sodium alginate was dissolved in 50 mL of deionized water, and then 8 g of boric acid and 2 g of cysteine ​​were added. After the sodium alginate was completely dissolved, 1.5 g of sodium molybdate was added and stirred until the solution was uniformly mixed. Then 2 g of calcium lignin sulfonate was added and stirred at room temperature for 12 h until the mixture formed a gel analogue. The gel analogue was placed in a 100 mL hydrothermal kettle, and the hydrothermal kettle was placed in an oven for hydrothermal carbonization at 220 °C for 12 h to obtain a hydrothermal carbon sample. The hydrothermal carbon sample obtained after hydrothermal carbonization was filtered and placed in an oven for drying at 80 °C for 24 h. The dried sample was then placed in a tubular furnace and calcined at 800 °C for 2 h under a nitrogen atmosphere (30-60 mL / min). After the tubular furnace was cooled, the sample was taken out, washed with water and ethanol solution, and dried in an oven at 100 °C for 12 h to obtain MoS2@BNC material.

[0055] (2) 1 g of the MoS2@BNC material obtained in step (1) was uniformly dispersed in 30 mL of deionized water, and then nickel nitrate was added (the mass of nickel in the nickel nitrate accounted for 1.0% of the mass of the MoS2@BNC material). After the nickel precursor was completely dissolved, it was stirred at room temperature for 12 h to obtain a catalyst precursor. Then, the obtained catalyst precursor was dried at 100 ° C for 12 h to obtain a biochar-supported nickel metal catalyst, which was recorded as Ni 1.0% / MoS2@BNC catalyst.

[0056] Ni 1.0% / MoS2@BNC catalyst needs to be reduced before use. The specific treatment operation is as follows:

[0057] The prepared Ni 1.0% / MoS2@BNC catalyst was placed in a pure hydrogen atmosphere with a hydrogen flow rate of 50-100 mL / min and reduced at 500 °C for 3.0 h. The hydrogen flow rate was adjusted according to the experimental conditions.

[0058] The catalyst after reduction was tested, and the HR-TEM image of the catalyst after reduction is shown as follows: Figure 1 As shown, the TEM mapping of the reduced catalyst is as follows Figure 2 As shown, from Figure 1 and Figure 2 It can be seen that Ni metal is uniformly dispersed on the catalyst carrier and the catalyst is successfully synthesized.

[0059] Embodiment 2:

[0060] 4-propylcatechol is commercially available, and can also be directly prepared by hydrogenolysis of lignocellulose, or by demethylation conversion of 4-propylguaiacol prepared by hydrogenolysis of lignocellulose.

[0061] 4-Propylcatechol was prepared by demethylation of 4-propylguaiacol:

[0062]

[0063] 4-Propylguaiacol (1.66 g, 0.01 mol) and 8.3 g of 48% hydrobromic acid aqueous solution catalyst were added into a pressure bottle, and the demethylation reaction was carried out at 115°C for 19 h to obtain 4-propylcatechol, which was recorded as compound 1, with a conversion rate of 85.7%.

[0064] The GC-MS image of compound 1 (4-propylcatechol) prepared in Example 2 is as follows: Figure 3 The NMR and mass spectrometry data of compound 1 are as follows: 1 H NMR (400 MHz, DMSO- d 6) δ 8.61 (s, 2H), 6.79 – 6.35 (m, 3H), 2.37(dd, J = 8.4, 6.8 Hz, 2H), 1.71 – 1.40 (m, 2H), 0.87 (t, J = 7.3 Hz, 3H). 13 C NMR(101 MHz, DMSO) δ 145.38, 143.53, 133.44, 119.36, 116.17, 115.84, 37.20,24.80, 14.06. MSI-MS: 153.2 [M+H] + .

[0065] Embodiment 3:

[0066]

[0067] 2,2'-Methylenebis(4-propylphenol) is commercially available and can also be converted by alkylation using 4-propylphenol from lignocellulose hydrogenolysis.

[0068] Preparation of 2,2'-methylenebis(4-propylphenol) by alkylation of 4-propylphenol:

[0069] 4-Propylphenol (0.01 mol), 6.8 g of 35% NaOH aqueous solution catalyst (containing 0.06 mol NaOH) and 37% formaldehyde aqueous solution (8.20 g, 0.1 mol) were added to a pressure bottle, and the alkylation reaction was carried out at 140°C for 3 h to prepare 2,2'-methylenebis(4-propylphenol), which was recorded as compound 2. The conversion rate of 4-propylphenol was 95.8%, and the selectivity of 2,2'-methylenebis(4-propylphenol) was 94.6%.

[0070] The GC-MS graph of compound 2 (2,2'-methylenebis(4-propylphenol)) prepared in Example 3 is as follows: Figure 4 The NMR and mass spectrometry data of compound 2 are: 1 H NMR (400 MHz, Chloroform- d ) δ 6.82 (m, 6H), 6.01(s, 2H), 3.96 (s, 2H), 2.61 (m, 4H), 1.68 – 1.60 (m, 4H), 0.94 (t, J = 7.3 Hz,6H). 13 C NMR (101 MHz, CDCl3) δ 150.56, 133.14, 128.16, 127.60, 119.75, 112.18,38.02, 29.56, 24.24, 13.74. MSI-MS: 285.4 [M+H] + .

[0071] Embodiment 4:

[0072]

[0073] 2-[(2-Hydroxy-3-methoxy-5-propylphenyl)methyl]-6-methoxy-4-propylphenol is commercially available and can also be converted by alkylation using 4-propylguaiacol obtained by hydrogenolysis of lignocellulose.

[0074] 2-[(2-hydroxy-3-methoxy-5-propylphenyl)methyl]-6-methoxy-4-propylphenol was prepared by alkylation of 4-propylguaiacol from lignocellulose hydrogenation:

[0075] 4-Propylguaiacol (0.01 mol), 6.8 g of 35% NaOH aqueous solution catalyst (containing 0.06 mol NaOH) and 37% formaldehyde aqueous solution (8.20 g, 0.1 mol) were added to a pressure bottle, and the alkylation reaction was carried out at 140°C for 3 h to prepare 2-[(2-hydroxy-3-methoxy-5-propylphenyl)methyl]-6-methoxy-4-propylphenol, which was recorded as compound 3. The conversion rate of 4-propylguaiacol was 93.5%, and the selectivity of compound 3 was 89.7%.

[0076] The GC-MS graph of compound 3 (2-[(2-hydroxy-3-methoxy-5-propylphenyl)methyl]-6-methoxy-4-propylphenol) prepared in Example 4 is as follows: Figure 5 The NMR and mass spectrometry data of compound 3 are as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 6.61 (dd, J = 23.5, 1.9 Hz, 4H), 6.01 (s, 2H), 3.96 (s, 2H), 3.88 (s, 6H), 2.49 (dd, J = 8.6, 6.7 Hz, 4H), 1.70 – 1.52 (m, 4H), 0.94 (t, J =7.3 Hz, 6H). 13 C NMR (101 MHz, CDCl3) δ 146.45, 141.04, 134.09, 126.17,122.40, 109.18, 55.98, 37.86, 29.44, 24.85, 13.84. MSI-MS: 345.5 [M+H] + .

[0077] Embodiment 5:

[0078]

[0079] 3,3'-Dimethoxy-5,5'-dipropylbiphenyl-2,2'-diol is commercially available and can also be converted by coupling with 4-propylguaiacol obtained by hydrogenolysis of lignocellulose.

[0080] Preparation of 3,3'-dimethoxy-5,5'-dipropylbiphenyl-2,2'-diol by coupling transformation of 4-propylguaiacol from lignocellulose hydrogenolysis:

[0081] 4-Propylguaiacol (0.01 mol), 10 mol% tetrabutylammonium iodide aqueous solution (containing 0.001 mol tetrabutylammonium iodide), 30% hydrogen peroxide aqueous solution (containing 0.012 mol hydrogen peroxide), 0.01 mol potassium carbonate and 20 mL ethyl acetate were added to a pressure bottle, and the coupling reaction was carried out at room temperature for 24 h to prepare 3,3'-dimethoxy-5,5'-dipropylbiphenyl-2,2'-diol, which was recorded as compound 4. The conversion rate of 4-propylguaiacol was 89.5%.

[0082] The GC-MS graph of compound 4 (3,3'-dimethoxy-5,5'-dipropylbiphenyl-2,2'-diol) prepared in Example 5 is as follows: Figure 6 The NMR and mass spectrometry data of compound 4 are as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 6.88 –6.62 (m, 4H), 6.05 (s, 2H), 3.95 (s, 6H), 2.59 (dd, J = 8.6, 6.8 Hz, 4H), 1.83– 1.60 (m, 4H), 0.99 (t, J = 7.3 Hz, 6H). 13 C NMR (101 MHz, CDCl3) δ 147.13,140.51, 134.70, 124.47, 122.99, 110.66, 56.09, 37.90, 24.79, 13.92. MSI-MS:331.4 [M+H] + .

[0083] Embodiment 6~9:

[0084] A method for preparing cyclic diamines by hydrogenating and aminating lignin-based aromatic diphenols, using compound 1, compound 2, compound 3, and compound 4 prepared in Examples 2 to 5 as reaction substrates, and using the reduced Ni prepared in Example 1 1.0% / MoS2@BNC catalyst was used to carry out hydrogenation amination experiment, specifically:

[0085] 0.1 g lignin-based diphenolic compound substrate, 0.2 g Ni 1.0% / MoS2@BNC catalyst and 10 mL of tert-amyl alcohol were added to a 50 mL reactor, and the stirring rate was set to 800 r / min; ammonia was first introduced for gas replacement, and then 0.7 MPa ammonia was introduced, and 3-8 MPa hydrogen was introduced. The reactor was reacted at 170 °C for 15-30 h. After the reaction was completed, the temperature was lowered and the exhaust gas was exhausted. The reaction solution was taken and n-heptane was added as an internal standard for GC-MS detection. The yield of the target product was as follows:

[0086] Table 1 Efficiency of hydroamination reaction of different substrates in Examples 6 to 9

[0087]

[0088] Among them, the NMR and mass spectrometry data of 4-propyl-1,2-cyclohexanediamine prepared using compound 1 as a substrate are as follows: 1 H NMR (400 MHz, DMSO-d6) δ 2.54 (m, 2H), 1.75-1.61 (m, 3H), 1.52-1.27 (m,10H), 1.21-1.15 (m, 2H), 0.85 (t, J = 7.3 Hz, 3H). 13 C NMR (100 MHz, DMSO-d6) δ57.7, 55.1, 37.8, 37.1, 30.5, 29.1, 28.3, 20.4, 14.2. MSI-MS: 157.3 [M+H] + .

[0089] Among them, the NMR and mass spectrometry data of 2,2'-methylenebis(4-propylcyclohexyl-1-amine) prepared using compound 2 or compound 3 as a substrate are: 1 H NMR (400 MHz, DMSO-d6) δ 2.45 (q, 2H), 1.74-1.59 (dd,4H), 1.54-1.11 (m, 26H), 0.88 (t, 6H). 13 C NMR (100 MHz, DMSO-d6) δ 53.5, 41.7,37.5, 34.6, 32.2, 32.0, 30.1, 28.9, 20.4, 14.5. MSI-MS: 295.5 [M+H] + .

[0090] Among them, the NMR and mass spectrometry data of 5,5'-dipropyl-[1,1'-bi(cyclohexane)]-2,2'-diamine prepared using compound 4 as a substrate are as follows:1 H NMR (400 MHz, DMSO-d6) δ 2.47 (m, 2H), 1.77-1.60 (dd,4H), 1.55-1.15 (m, 24H), 0.89 (t, 6H). 13 C NMR (100 MHz, DMSO-d6) δ 50.8, 37.9,37.6, 32.4, 32.2, 30.1, 28.8, 20.4, 14.4. MSI-MS: 281.6 [M+H] + .

[0091] Example 10: Comparative Example

[0092] The experimental method is the same as that of Example 6, except that the catalyst is a commercial NiMoS2 catalyst.

[0093] A method for preparing cyclic diamines by hydrogenation amination of lignin-based aromatic diphenols, using compound 1 prepared in Example 2 as a reaction substrate, and using commercial NiMoS2 catalyst (Jiangsu Yangzi Catalyst Co., Ltd.) to carry out hydrogenation amination experiments, specifically:

[0094] 0.1 g of compound 1, 0.2 g of NiMoS2 catalyst and 10 mL of tert-amyl alcohol were added to a 50 mL reactor, and the stirring rate was set to 800 r / min; ammonia was first introduced into the reactor for gas replacement, and then 0.7 MPa ammonia was introduced, and 3 MPa hydrogen was introduced into the reactor. The reactor was reacted at 170°C for 15 h. After the reaction was completed, the temperature was lowered and the exhaust gas was discharged. The reaction liquid was taken and n-heptane was added as an internal standard, and GC-MS detection was performed. The conversion rate of compound 1 was 52.6%, and the yield of the corresponding lignin-based diamine product was 35.8%.

[0095] The experimental results show that in the hydrogenation amination experiment of lignin-based diphenol compound substrates catalyzed by commercial NiMoS2 catalyst, the reaction conversion rate of the substrate and the yield of the product are lower than the catalytic effect of the Ni / MoS2@BNC catalyst provided by the present invention.

[0096] Example 11: Comparative Example

[0097] The experimental method is the same as that of Example 6, except that the catalyst is a commercial Raney nickel catalyst.

[0098] A method for preparing cyclic diamines by hydrogenation amination of lignin-based aromatic diphenols, using compound 1 prepared in Example 2 as a reaction substrate, and using a commercial Raney nickel catalyst (McLean, 20-40 mesh, dispersed in water) to carry out a hydrogenation amination experiment, specifically:

[0099] 0.1 g of compound 1, 0.2 g of Raney nickel catalyst and 10 mL of tert-amyl alcohol were added to a 50 mL reactor, and the stirring rate was set to 800 r / min; ammonia was first introduced into the reactor for gas replacement, and then 0.7 MPa ammonia was introduced, and 3 MPa hydrogen was introduced into the reactor. The reactor was reacted at 170°C for 15 h. After the reaction was completed, the temperature was lowered and the exhaust was exhausted. The reaction solution was taken and n-heptane was added as an internal standard, and GC-MS detection was performed. The conversion rate of compound 1 was 72.6%, and the yield of the corresponding lignin-based diamine product was 54.3%.

[0100] The experimental results show that when the commercial Raney nickel catalyst is used to catalyze the hydrogenation amination of lignin-based diphenol compounds, the reaction conversion rate of the substrate and the yield of the product are lower than the catalytic effect of the Ni / MoS2@BNC catalyst provided by the present invention.

[0101] Example 12: Comparative Example

[0102] The experimental method is the same as that of Example 7, except that the catalyst is a commercial NiMoS2 catalyst.

[0103] A method for preparing cyclic diamines by hydrogenation amination of lignin-based aromatic diphenols, using compound 2 prepared in Example 3 as a reaction substrate, and using commercial NiMoS2 catalyst (Jiangsu Yangzi Catalyst Co., Ltd.) to carry out hydrogenation amination experiments, specifically:

[0104] 0.1 g of compound 2, 0.2 g of NiMoS2 catalyst and 10 mL of tert-amyl alcohol were added to a 50 mL reactor, and the stirring rate was set to 800 r / min; ammonia was first introduced into the reactor for gas replacement, and then 0.7 MPa ammonia was introduced, and 5 MPa hydrogen was introduced into the reactor. The reactor was reacted at 170°C for 18 h. After the reaction was completed, the temperature was cooled and the exhaust was exhausted. The reaction liquid was taken and n-heptane was added as an internal standard for GC-MS detection. The conversion rate of compound 2 was 35.9%, and the yield of the corresponding lignin-based diamine product was 20.5%.

[0105] The experimental results show that in the hydrogenation amination experiment of lignin-based diphenol compound substrates catalyzed by commercial NiMoS2 catalyst, the reaction conversion rate of the substrate and the yield of the product are lower than the catalytic effect of the Ni / MoS2@BNC catalyst provided by the present invention.

[0106] Embodiment 13:

[0107] Ni / MoS2@BNC catalysts with different contents were prepared and applied to the hydrogenation amination experiment. The preparation methods of Ni / MoS2@BNC catalysts with different contents were the same as those in Example 1, except that the mass of nickel in nickel nitrate accounted for 0.5%, 5.0%, and 10.0% of the mass of MoS2@BNC material, respectively. Hydrogenation amination experiments were carried out using Ni / MoS2@BNC catalysts with different contents prepared in this example (Ni / MoS2@BNC catalysts needed to be reduced using the reduction treatment method in Example 1 before use). The experimental methods and experimental conditions were the same as those in Example 6. The raw material was compound 1. The specific conversion rate of compound 1 and the yield of 4-propyl-1,2-cyclohexanediamine are shown in Table 2.

[0108] Table 2

[0109]

[0110] The present invention provides a method and idea for preparing lignin-based aliphatic cyclic diamines by hydrogenating and aminating lignin-based aromatic diphenols. There are many methods and approaches to realize the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be realized by existing technologies.

Claims

1. A method for preparing lignin-based aliphatic cyclic diamines by hydrogenating and aminating lignin-based aromatic diphenols, characterized in that: Using lignin-based aromatic diphenol as raw material and ammonia as gas source, a hydrogenation amination reaction is carried out in a reaction solvent under the action of nickel metal catalyst supported by biochar and hydrogen atmosphere to prepare lignin-based aliphatic cyclic diamine; The biochar-supported nickel metal catalyst comprises a boron- and nitrogen-doped biochar-supported molybdenum sulfide carrier and an effective active component supported on the boron- and nitrogen-doped biochar-supported molybdenum sulfide carrier; the effective active component is nickel metal; The biochar-supported nickel metal catalyst is prepared according to the following steps: (1) mixing sodium alginate with boric acid, sulfur-containing amino acid, molybdate, lignin sulfonate, and a first solvent, stirring to obtain a gel analog; hydrothermally carbonizing the gel analog to obtain a hydrothermal carbon sample; drying the hydrothermal carbon sample, calcining, washing, and drying to obtain a boron- and nitrogen-doped biochar-loaded molybdenum sulfide carrier; (2) mixing the boron and nitrogen-doped biochar-loaded molybdenum sulfide carrier obtained in step (1) with a second solvent and a nickel precursor, and stirring to obtain a catalyst precursor; drying the catalyst precursor to obtain a biochar-loaded nickel metal catalyst; In the hydrogenation amination reaction process, the pressure of ammonia is 0.5-2.0 MPa, the pressure of hydrogen is 1.0-10.0 MPa, the reaction temperature is 150-200° C., and the reaction time is 15.0-35.0 h.

2. The method according to claim 1, characterized in that When the lignin-based aromatic diphenol is selected from When the prepared lignin-based aliphatic cyclic diamine is When the lignin-based aromatic diphenol is selected from When the prepared lignin-based aliphatic cyclic diamine is When the lignin-based aromatic diphenol is selected from When the prepared lignin-based aliphatic cyclic diamine is When the lignin-based aromatic diphenol is selected from When the prepared lignin-based aliphatic cyclic diamine is 3. The method according to claim 1, characterized in that The reaction solvent is any one of methanol, isopropanol and tert-amyl alcohol or a combination of several thereof; the mass ratio of the lignin-based aromatic diphenol to the nickel in the biochar-loaded nickel metal catalyst is 5:1 to 200:

1.

4. The method according to claim 1, characterized in that: The sulfur-containing amino acid is any one of cysteine ​​and cystine or a combination of two; the molybdate is any one of sodium molybdate and ammonium molybdate or a combination of two; the lignin sulfonate is any one of calcium lignin sulfonate and sodium lignin sulfonate or a combination of two; the first solvent is water; the second solvent is water; the nickel precursor is any one of nickel chloride, nickel sulfate, nickel nitrite and nickel nitrate or a combination of several thereof.

5. The method according to claim 1, characterized in that: In step (1), the mass ratio of sodium alginate to boric acid, sulfur-containing amino acid, molybdate, and lignin sulfonate is 1.0-3.0:6.0-10.0:1.0-3.0:1.0-2.5:1.0-4.

0.

6. The method according to claim 1, characterized in that In step (1), the stirring is carried out at room temperature for 8 to 16 hours; the hydrothermal carbonization is carried out at a carbonization temperature of 180 to 220° C. for 8 to 16 hours; and the calcination is carried out under the protection of an inert gas at a temperature of 700 to 900° C. for 1 to 4 hours.

7. The method according to claim 1, characterized in that In step (2), the mass of nickel in the nickel precursor accounts for 0.5% to 10% of the mass of the boron- and nitrogen-doped biochar-loaded molybdenum sulfide carrier; the stirring is carried out at room temperature for 8 to 24 hours.

8. The method according to claim 1, characterized in that: The biochar-loaded nickel metal catalyst needs to be reduced before use. Specifically, the biochar-loaded nickel metal catalyst is reduced at 400-550° C. in a hydrogen environment for 2-4 hours.

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