A method for catalyzing the hydrogenation of long-chain diols using a highly efficient MOF catalyst

Abstract

The present application relates to a kind of efficient MOF catalyst for catalyzing the method of long-chain dihydric alcohol hydrogenation reaction, the method uses Cu / Fe-Mo2C as catalyst, wherein Mo2C is carrier, Cu is active component, Fe is adjuvant, specific reaction process is as follows: after being loaded into fixed bed reactor, hydrogen is sent to fixed bed reactor, catalyst is reduced at 250~300 DEG C for 6~8h, after reduction ends, temperature is reduced to amination reaction temperature, raw material long-chain dihydric alcohol is dissolved in solvent tetrahydrofuran and is prepared into 10wt%~30wt% solution, then the aforementioned solution is mixed with liquid ammonia according to certain proportion, is uniformly sent to reactor by raw material pump, adjusts reaction parameter and carries out amination reaction.The present application does not need to carry out pre-activation treatment to catalyst, and reaction conversion rate is above 90% at 130 DEG C, reaction selectivity is above 95%, it shows that long-chain dihydric alcohol hydrogenation reaction can be effectively catalyzed at low temperature, it is favorable to reduce energy consumption, save cost.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for catalyzing the hydrogenation of long-chain diols using a high-efficiency MOF catalyst, and more particularly to a method for preparing an MOF catalyst and its use in the hydrogenation of long-chain diols, belonging to the field of fine chemical industry. BACKGROUND

[0002] Long-chain nylon has excellent properties such as low water absorption, good dimensional stability of products, good self-lubricity, good flexibility, and impact resistance. It has become an indispensable high-value-added material in the fields of automobiles, aerospace, electronics, and permeation separation. The production of long-chain diamines, which are the main raw materials for long-chain nylon, limits the development of long-chain nylon.

[0003] Traditional methods for synthesizing amines include the amination of halogenated hydrocarbons, the reductive amination of olefins, and the reductive amination of acids. Currently, long-chain diamines are mainly prepared by a two-step method of amination and dehydration of long-chain diacids to prepare nitriles, and hydrogenation of nitriles to prepare amines. This process has the disadvantages of complex route, heavy pollution, and low yield. Using long-chain diols as raw materials for amination reaction under hydrogen atmosphere not only has low cost but also is green and environmentally friendly, and has high atom economy. The reaction mechanism of this reaction is that the hydroxyl group in the alcohol is dehydrogenated to a carbonyl group, the carbonyl group is aminated to obtain an imine intermediate, and finally the imine is hydrogenated to form an amine. Therefore, this reaction needs to be catalyzed by a dehydrogenation / hydrogenation catalyst.

[0004] Traditional noble metal-based hydrogenation / dehydrogenation catalysts such as Pt and Pd are difficult to be widely used in large-scale industrial production due to their high price and limited reserves. In the existing technologies reported, Pt-based or Ni-based metal catalysts supported by metal oxides or zeolite molecular sieves are often used, but there are often problems such as high reaction temperature, poor selectivity, and the need for pretreatment of the catalyst before the reaction. For example, the catalyst for the hydrogenation of dodecanediol reported in patent CN116143634A needs to be activated for 10-15 h using ammonia water after reduction, and the catalyst for the hydrogenation of polyether alcohol reported in patent CN115739102A needs to be pretreated using organic amine vapor, which makes the reaction steps more complex. SUMMARY

[0005] The present application aims to provide a method for catalyzing the hydrogenation of long-chain diols using a high-efficiency MOF catalyst.

[0006] Applicant found that Mo2C as a MOF material has very high specific surface area and porosity, which can effectively disperse metal active components to improve catalytic activity. In addition, due to the increase of Mo-Mo bond length in the preparation process, the lattice of the metal matrix is expanded, and the partial 4d electrons of Mo in Mo2C become local electrons similar to noble metals, so that it has similar catalytic performance to Pt group noble metals, thereby further improving the hydrogenation catalytic activity of the catalyst. When using Cu / Fe-Mo2C as a catalyst to catalyze the long-chain diol hydrogenation reaction, the catalyst does not need to be pre-activated, and the reaction temperature is lower and the reaction performance is better, which is beneficial to save reaction time and reduce reaction energy consumption.

[0007] Based on the above research, the high-efficiency MOF catalyst for catalyzing long-chain diol hydrogenation reaction in the method of the application uses Cu / Fe-Mo2C as a catalyst, wherein Mo2C is the carrier, Cu is the active component, and Fe is the additive.

[0008] The structural formula of the reaction raw material long-chain diol is: OH-CH2-(CH2) n -CH2-OH (wherein 8≤n≤12).

[0009] The reaction parameters are as follows: the molar ratio of raw material alcohol to liquid ammonia is 1:2-1:12, the reaction temperature is 130-200℃, the hydrogen pressure is 1-6 MPa, the volume space velocity is 0.2-1.5 h -1 , and the hydrogen flow rate is 1-20 L / h.

[0010] The preparation method of the catalyst Cu / Fe-Mo2C used in the application comprises the following steps:

[0011] (1) A corresponding amount of H3PO4·12MoO3, trimesic acid, L-glutamic acid, and copper acetate Cu(CH3CO2)2·H2O are weighed and dissolved in a 10wt% ethanol aqueous solution, and stirred at room temperature until mixed uniformly;

[0012] (2) The mixed solution is centrifuged 3 times, washed to obtain a solid precipitate, and then placed in an oven for drying. The dried solid is placed in a tube furnace, the temperature in the furnace is controlled, the temperature is increased to a certain temperature at a rate of 5℃ / min, and the black Cu@Mo2C powder is obtained by heat treatment under Ar atmosphere (20-100 L / h);

[0013] (3) The Cu@Mo2C is ultrasonically dispersed in deionized water, a certain amount of iron salt is added, and the mixed solution is stirred at 40℃ until mixed uniformly. NaCl solution is added and stirred at 40℃ for 10-24h to remove the residue. The obtained solution is separated by suction filtration, and the separated solid is washed with deionized water and dried to obtain the deposit Cu / Fe-Mo2C.

[0014] Further, the molar ratio of the supported metals Fe and Cu in the catalyst is 1:1-1:5.

[0015] Further, the molar ratio of copper acetate Cu(CH3CO2)2·H2O, L-glutamic acid, H3PO4·12MoO3, and trimesic acid in step (1) is 1:(0.2-0.6):(0.1-0.4):(0.3-0.9).

[0016] Further, the drying temperature in step (2) is 70-120℃.

[0017] Further, the temperature in the tube furnace in step (2) is 400-800℃.

[0018] Further, the drying temperature in step (3) is 60-120℃.

[0019] The method for the hydrogenation amination reaction of long-chain diols comprises the following steps: after the catalyst is loaded into a fixed bed reactor, a certain flow rate of hydrogen is delivered through a flow meter; the catalyst is reduced at 250-300℃ for 6-8h, and then cooled to the amination reaction temperature; the raw material long-chain diol, solvent tetrahydrofuran, and liquid ammonia are mixed uniformly in a certain proportion and delivered to the reactor through a raw material pump; and the reaction parameters are adjusted to perform the amination reaction.

[0020] Compared with the prior art, the hydrogenation amination reaction catalyst is prepared by innovatively using the MOF material Mo2C having Pt group metal characteristics as a carrier to support metals Cu and Fe, the catalyst has high activity, does not need to be pre-activated when used for the hydrogenation amination reaction of long-chain diols, has excellent reaction performance at a lower temperature, the reaction conversion rate is above 90% and the reaction selectivity is above 95% at 130℃, is conducive to simplifying the reaction steps, reducing the reaction time and energy consumption, and saving costs. DETAILED DESCRIPTION

[0021] The present application is described in detail below in combination with examples and comparative examples.

[0022] Example 1

[0023] Take 34.06 g H3PO4·12MoO3, 19.61 g of trimesic acid, 8.58 g of L-glutamic acid, 23.29 g of Cu(CH3CO2)2·H2O (the molar ratio of Cu(CH3CO2)2·H2O, L-glutamic acid, H3PO4·12MoO3, and trimesic acid is 1:0.5:0.15:0.8) and dissolve them in 10% ethanol aqueous solution. Stir the mixture at a speed of 500 r / min for 20 h at room temperature. Centrifuge the mixture three times, wash the precipitate three times, and then dry the precipitate in an oven at 70°C for 12 h. Put the dried solid into a tube furnace and heat it to 500°C at a rate of 5°C / min under Ar atmosphere (20 L / h). Heat-treat the solid to obtain black Cu@Mo2C precursor powder. Ultrasonically disperse the Cu@Mo2C powder in deionized water, then add 15.77 g of FeCl3·6H2O and mix well (the molar ratio of Fe to Cu is 1:2). Stir the mixture at 40°C for 18 h, add NaCl solution, and continue to stir at 40°C for 12 h to remove the residue. Separate the obtained solution by suction filtration three times, wash the separated solid with deionized water three times, and then dry the solid at 60°C for 12 h to obtain the catalyst.

[0024] After cooling the catalyst prepared above to room temperature, load it into the constant temperature section of a fixed bed reactor. Use a flowmeter to deliver hydrogen at a certain flow rate. After the flow rate is stable, start heating, and reduce the catalyst at 250°C. After 6 h of reduction, cool the catalyst to the amination reaction temperature. Dissolve decanediol in tetrahydrofuran to prepare a 30 wt% solution. Mix the solution with liquid ammonia uniformly (the molar ratio of decanediol to liquid ammonia is 1:8). Inject the mixture into the fixed bed reactor through a feed pump at a certain flow rate. Adjust the reaction parameters to perform the amination reaction. The reaction conditions and results are shown in Table 1.

[0025] Table 1 Reaction conditions and results of Example 1

[0026] Reaction temperature / °C airspeed / h -1 ]] Pressure / MPa Hydrogen flow rate / (L / h) Reaction conversion rate X / % Reaction selectivity S / % 130 0.3 6.0 1.0 90.65 95.65 150 0.5 4.5 7.5 94.78 93.85 170 0.8 2.5 12.5 95.63 91.37 190 1.0 1.0 20.0 95.96 90.62

[0027] Example 2

[0028] Take 45.63 g of H3PO4·12MoO3, 18.38 g of trimesic acid, 7.36 g of L-glutamic acid, 24.95 g of Cu(CH3CO2)2·H2O (the molar ratio of Cu(CH3CO2)2·H2O, L-glutamic acid, H3PO4·12MoO3, and trimesic acid is 1:0.4:0.2:0.7), dissolve them in 10% ethanol aqueous solution, stir at room temperature at a speed of 500 r / min for 20 h to mix uniformly. The above mixed solution is centrifuged for 3 times, washed for 3 times to obtain a solid precipitate, and placed in a 100°C oven to dry for 12 h. The dried solid is placed in a tube furnace and heated to 500°C at a rate of 5°C / min under Ar atmosphere (20 L / h), and the black Cu@Mo2C precursor powder is obtained by heat treatment. The Cu@Mo2C powder is ultrasonically dispersed in deionized water, then 16.92 g of FeCl3·6H2O is added and mixed uniformly (the molar ratio of Fe and Cu is 1:2), stirred at 40°C for 18 h, and then NaCl solution is added and stirred at 40°C for 12 h to remove the residue. The obtained solution is separated by suction filtration for 3 times, and the solid obtained after separation is washed with deionized water for 3 times and dried at 90°C for 12 h to obtain the catalyst.

[0029] After the catalyst is cooled to room temperature, it is loaded into the constant temperature section of the fixed bed reactor, and hydrogen is transported at a certain flow rate by using a flow meter. After the flow rate is stable, the temperature is increased, and the catalyst is reduced at 250°C. After 6 h of reduction, the temperature is decreased to the amination reaction temperature. The raw material decanediol is dissolved in tetrahydrofuran to prepare a 30wt% solution, and the solution is mixed uniformly with liquid ammonia in a certain proportion (the amount-of-substance ratio of decanediol to liquid ammonia is 1:6). The mixture is injected into the fixed bed reactor at a certain flow rate by using a raw material pump, and the reaction parameters are adjusted to perform the amination reaction. The reaction conditions and results are shown in Table 2.

[0030] Table 2 Reaction conditions and reaction results of Example 2

[0031] Reaction temperature / °C airspeed / h -1 ]]> Pressure / MPa Hydrogen flow rate / (L / h) Reaction conversion rate X / % Reaction selectivity S / % 140 0.3 5.0 3.0 90.63 96.45 160 0.5 4.0 7.5 91.85 91.74 180 0.8 2.5 15.0 94.60 92.51 200 1.0 1.5 18.5 96.37 90.26

[0032] Example 3

[0033] Cu(CH3CO2)2·H2O, L-glutamic acid, H3PO4·12MoO3, and trimesic acid were dissolved in 10% ethanol aqueous solution, and stirred at a rate of 500 r / min for 20 h at room temperature to mix uniformly. The mixed solution was subjected to 3 times of centrifugation and 3 times of washing to obtain a solid precipitate, which was dried in an oven at 120℃ for 12 h. The dried solid was placed in a tube furnace and heated to 500℃ at a rate of 5℃ / min under Ar atmosphere (40 L / h), and was heat-treated to obtain black Cu@Mo2C precursor powder. The Cu@Mo2C powder was ultrasonically dispersed in deionized water, and then 10.01 g of FeCl3·6H2O (molar ratio of Fe to Cu was 1:3) solution was added to mix uniformly. The mixture was stirred at 40℃ for 18 h, and NaCl solution was added to continue stirring at 40℃ for 15 h to remove residues. The obtained solution was subjected to 3 times of separation by suction filtration, and the solid obtained after separation was washed with deionized water for 3 times and dried at 120℃ for 12 h to obtain a catalyst.

[0034] After the catalyst was cooled to room temperature, it was loaded into the constant temperature section of a fixed bed reactor, and hydrogen was transported at a certain flow rate by using a flow meter. After the flow rate was stabilized, the temperature was increased, and the catalyst was reduced at 250℃. After reduction for 6 h, the temperature was decreased to the amination reaction temperature. Decanediol was dissolved in tetrahydrofuran to prepare a 30 wt% solution, and the solution was uniformly mixed with liquid ammonia (the amount-of-substance ratio of decanediol to liquid ammonia was 1:2). The mixture was injected into the fixed bed reactor by using a raw material pump at a certain flow rate, and the amination reaction was performed by adjusting the reaction parameters. The reaction conditions and results are shown in Table 3.

[0035] Table 3 Reaction conditions and reaction results of Example 3

[0036] Reaction temperature / °C airspeed / h -1 ]]> Pressure / MPa Hydrogen flow rate / (L / h) Reaction conversion rate X / % Reaction selectivity S / % 140 0.2 6.0 2.5 90.78 95.16 160 0.4 4.5 4.0 92.45 93.70 180 0.6 2.5 6.5 93.69 92.50 200 0.8 1.0 10.5 96.18 90.57

[0037] Example 4

[0038] A mixture of 34.06 g of H3PO4·12MoO3, 19.61 g of trimesic acid, 8.58 g of L-glutamic acid, 23.29 g of Cu(CH3CO2)2·H2O (molar ratio of Cu(CH3CO2)2·H2O, L-glutamic acid, H3PO4·12MoO3, trimesic acid = 1:0.3:0.3:0.9) was dissolved in 10% ethanol aqueous solution, and stirred at a rate of 500 r / min for 20 h at room temperature to mix uniformly. The above mixed solution was subjected to 3 times of centrifugation, 3 times of washing to obtain a solid precipitate, and was placed in an oven at 90°C for drying for 12 h. The dried solid was placed in a tube furnace, and was heated at a rate of 5°C / min to 600°C under Ar atmosphere (40 L / h) to obtain a black Cu@Mo2C precursor powder by heat treatment. The Cu@Mo2C powder was ultrasonically dispersed in deionized water, and then 15.77 g of FeCl3·6H2O (molar ratio of Fe and Cu = 1:3) was added to mix uniformly, and stirred at 40°C for 18 h. NaCl solution was added to continue stirring at 40°C for 12 h to remove residues. The obtained solution was subjected to 3 times of separation by suction filtration, and the solid obtained after separation was washed with deionized water for 3 times, and then dried at 90°C for 12 h to obtain a catalyst.

[0039] After the catalyst was cooled at room temperature, it was loaded into a constant temperature section of a fixed bed reactor, and hydrogen was transported at a certain flow rate by using a flow meter. After the flow rate was stabilized, the temperature was increased, and the catalyst was reduced at 250°C. After reduction for 6 h, the temperature was decreased to an amination reaction temperature. A raw material dodecanediol was dissolved in tetrahydrofuran to prepare a 30 wt% solution, and the solution was uniformly mixed with liquid ammonia in a certain proportion (wherein the amount-of-substance ratio of dodecanediol to liquid ammonia was 1:12). The mixture was injected into the fixed bed reactor at a certain flow rate by using a raw material pump, and the amination reaction was carried out by adjusting reaction parameters.

[0040] Table 4 Reaction conditions and reaction results of Example 4

[0041]

[0042]

[0043] Example 5

[0044] Take 45.63 g of H3PO4·12MoO3, 18.38 g of trimesic acid, 7.36 g of L-glutamic acid, 24.95 g of Cu(CH3CO2)2·H2O (the molar ratio of Cu(CH3CO2)2·H2O, L-glutamic acid, H3PO4·12MoO3, and trimesic acid is 1:0.4:0.2:0.7), dissolve them in 10% ethanol aqueous solution, stir at room temperature at a speed of 500 r / min for 20 h to mix uniformly. Centrifuge the above mixed solution for 3 times, wash for 3 times to obtain a solid precipitate, and place it in a 100°C oven to dry for 12 h. Put the dried solid into a tube furnace, heat to 600°C at a rate of 5°C / min under Ar atmosphere (60 L / h), and heat treat to obtain black Cu@Mo2C precursor powder. Ultrasonic disperse the Cu@Mo2C powder in deionized water, then add 16.92 g of FeCl3·6H2O (the molar ratio of Fe and Cu is 1:2) and mix uniformly, stir at 40°C for 18 h, add NaCl solution and continue to stir at 40°C for 12 h to remove residues. Perform suction filtration on the obtained solution for 3 times, wash the obtained solid after separation with deionized water for 3 times, and dry at 100°C for 12 h to obtain the catalyst.

[0045] After the catalyst is cooled at room temperature, it is loaded into the constant temperature section of the fixed bed reactor, hydrogen is transported at a certain flow rate by using a flow meter, and after the flow rate is stable, the temperature is increased, and the catalyst is reduced at 250°C. After reduction for 6 h, the temperature is decreased to the amination reaction temperature. The raw material dodecanediol is dissolved in tetrahydrofuran to prepare a 30 wt% solution, the solution is uniformly mixed with liquid ammonia in proportion (the amount-of-substance ratio of dodecanediol to liquid ammonia is 1:8), and the solution is injected into the fixed bed reactor at a certain flow rate by using a raw material pump, and the reaction parameters are adjusted to perform amination reaction. The reaction conditions and results are shown in Table 5.

[0046] Table 5 Reaction conditions and reaction results of Example 5

[0047] Reaction temperature / °C airspeed / h -1 ]]> Pressure / MPa Hydrogen flow rate / (L / h) Reaction conversion rate X / % Reaction selectivity S / % 140 0.4 5.0 3.5 90.65 95.74 160 0.6 4.0 7.5 92.38 93.68 180 1.0 2.5 12.5 95.47 91.74 200 1.2 1.5 16.0 96.20 90.25

[0048] Example 6

[0049] A mixture of 40.55 g of H3PO4·12MoO3, 21.02 g of trimesic acid, 9.80 g of L-glutamic acid, 22.18 g of Cu(CH3CO2)2·H2O (molar ratio of Cu(CH3CO2)2·H2O, L-glutamic acid, H3PO4·12MoO3, trimesic acid = 1:0.6:0.2:0.9) was dissolved in 10% ethanol aqueous solution, and stirred at a rate of 500 r / min at room temperature for 20 h to mix uniformly. The above mixed solution was subjected to 3 times of centrifugation, 3 times of washing to obtain a solid precipitate, and was placed in a 100℃ oven to dry for 12 h. The dried solid was placed in a tube furnace, and heated to 600℃ at a rate of 5℃ / min under Ar atmosphere (60 L / h) to obtain a black Cu@Mo2C precursor powder by heat treatment. The Cu@Mo2C powder was ultrasonically dispersed in deionized water, and then 10.01 g of FeCl3·6H2O (molar ratio of Fe and Cu = 1:3) was added to mix uniformly, and stirred at 40℃ for 18 h. NaCl solution was added to continue stirring at 40℃ for 15 h to remove residues. The obtained solution was subjected to 3 times of separation by suction filtration, and the solid obtained after separation was washed with deionized water for 3 times, and then dried at 120℃ for 12 h to obtain a catalyst.

[0050] After the catalyst was cooled at room temperature, it was loaded into the constant temperature section of a fixed bed reactor, and hydrogen was transported at a certain flow rate by using a flow meter. After the flow rate was stabilized, the temperature was increased, and the catalyst was reduced at 250℃. After reduction for 6 h, the temperature was decreased to the amination reaction temperature. The raw material dodecanediol was dissolved in tetrahydrofuran to prepare a 30wt% solution, and the solution was uniformly mixed with liquid ammonia in proportion (wherein the amount-of-substance ratio of dodecanediol to liquid ammonia was 1:6). The mixture was injected into the fixed bed reactor at a certain flow rate by using a raw material pump, and the amination reaction was carried out by adjusting the reaction parameters. The reaction conditions and results are shown in Table 6.

[0051] Table 6 Reaction conditions and reaction results of Example 6

[0052] Reaction temperature / °C airspeed / h -1 ]]> Pressure / MPa Hydrogen flow rate / (L / h) Reaction conversion rate X / % Reaction selectivity S / % 130 0.4 5.0 3.5 90.82 95.60 150 0.6 3.5 5.5 92.86 93.41 180 1.0 2.5 8.0 93.85 90.60 200 1.2 1.5 12.0 96.27 90.32

[0053] Example 7

[0054] A mixture of 115.18 g of H3PO4·12MoO3, 29.55 g of trimesic acid, 4.60 g of L-glutamic acid, 31.19 g of Cu(CH3CO2)2·H2O (molar ratio of Cu(CH3CO2)2·H2O, L-glutamic acid, H3PO4·12MoO3, trimesic acid = 1:0.2:0.4:0.9) was dissolved in 10% ethanol aqueous solution, and stirred at a rate of 500 r / min at room temperature for 20 h to mix uniformly. The above mixed solution was subjected to 3 times of centrifugation, 3 times of washing to obtain a solid precipitate, and was placed in an oven at 80°C for drying for 12 h. The dried solid was placed in a tube furnace, and was heated at a rate of 5°C / min to 600°C under Ar atmosphere (30 L / h) to obtain a black Cu@Mo2C precursor powder by heat treatment. The Cu@Mo2C powder was ultrasonically dispersed in deionized water, and then 4.57 g of FeCl3·6H2O (molar ratio of Fe and Cu = 1:1) was added to mix uniformly, and stirred at 40°C for 18 h. NaCl solution was added to continue stirring at 40°C for 15 h to remove residues. The obtained solution was subjected to 3 times of separation by suction filtration, and the solid obtained after separation was washed with deionized water for 3 times and dried at 80°C for 12 h to obtain a catalyst.

[0055] After the catalyst was cooled at room temperature, it was loaded into a constant temperature section of a fixed bed reactor, and a flow meter was used to transport hydrogen at a certain flow rate. After the flow rate was stabilized, the temperature was increased, and the catalyst was reduced at 280°C. After reduction for 8 h, the temperature was decreased to the amination reaction temperature. The raw material decanediol was dissolved in tetrahydrofuran to prepare a 30 wt% solution, and the solution was uniformly mixed with liquid ammonia in a certain proportion (wherein the amount-of-substance ratio of decanediol to liquid ammonia was 1:8). The mixture was injected into the fixed bed reactor by a raw material pump at a certain flow rate, and the reaction parameters were adjusted to perform amination reaction. The reaction conditions and results are shown in Table 7.

[0056] Table 7 Reaction conditions and reaction results of Example 7

[0057] Reaction temperature / °C airspeed / h -1 ]] Pressure / MPa Hydrogen flow rate / (L / h) Reaction conversion rate X / % Reaction selectivity S / % 140 0.3 4.0 2.5 90.35 96.86 160 0.5 3.0 4.0 92.56 92.74 170 0.8 2.5 7.5 96.78 91.86 190 1.0 1.0 10.0 97.69 90.74

[0058] Example 8

[0059] Take 45.64 g H3PO4·12MoO3, 21.01 g trimesic acid, 9.19 g L-glutamic acid, 24.96 g Cu(CH3CO2)2·H2O (the molar ratio of Cu(CH3CO2)2·H2O, L-glutamic acid, H3PO4·12MoO3, and trimesic acid is 1:0.5:0.2:0.8) into 10% ethanol aqueous solution, and stir at a speed of 500 r / min at room temperature for 20 h to mix uniformly. The mixed solution is centrifuged for 3 times, washed for 3 times to obtain a solid precipitate, and placed in a 100℃ oven to dry for 12 h. The dried solid is placed in a tube furnace and heated to 600℃ at a rate of 5℃ / min under Ar atmosphere (50 L / h), and heat-treated to obtain black Cu@Mo2C precursor powder. The Cu@Mo2C powder is ultrasonically dispersed in deionized water, and then 23.73 g FeCl3·6H2O is added to mix uniformly (the molar ratio of Fe and Cu is 1:5). Stirring is performed at 40℃ for 18 h, and NaCl solution is added to continue stirring at 40℃ for 15 h to remove residues. The obtained solution is separated by suction filtration for 3 times, and the solid obtained after separation is washed with deionized water for 3 times, and then dried at 1000℃ for 12 h to obtain the catalyst.

[0060] After the catalyst is cooled at room temperature, it is loaded into the constant temperature section of a fixed bed reactor, and a flow meter is used to transport hydrogen at a certain flow rate. After the flow rate is stable, the temperature is increased, and the catalyst is reduced at 280℃. After reduction for 8 h, the temperature is decreased to the amination reaction temperature. The raw material dodecanediol is dissolved in tetrahydrofuran to prepare a 30wt% solution, and the solution is uniformly mixed with liquid ammonia in proportion (the amount-of-substance ratio of dodecanediol to liquid ammonia is 1:10). The mixture is injected into the fixed bed reactor through a raw material pump at a certain flow rate, and the reaction parameters are adjusted to perform amination reaction. The reaction conditions and results are shown in Table 8.

[0061] Table 8 Reaction conditions and reaction results of Example 8

[0062] Reaction temperature / °C airspeed / h -1 ]] Pressure / MPa Hydrogen flow rate / (L / h) Reaction conversion rate X / % Reaction selectivity S / % 140 0.4 5.0 3.0 90.36 95.27 160 0.6 3.5 5.5 92.58 93.25 180 1.0 2.0 8.0 95.63 91.80 200 1.2 1.0 11.0 97.76 90.68

[0063] Comparative Example 1

[0064] A catalyst Cu-Fe / SiO2 (wherein the content of Cu and Fe in the catalyst is the same as the catalyst prepared in Example 1, only the carrier is changed to SiO2) was prepared by a precipitation method. 27.40 g of Cu(NO3)2 3H2O and 12.94 g of FeCl3 6H2O were weighed into a 500 mL round-bottom flask, and deionized water was measured and added to the flask to dissolve by stirring to obtain a mixed metal ion solution. 12.03 g of SiO2 was weighed into a beaker and 400 mL of deionized water was added to obtain a suspension. An appropriate amount of K2CO3 was dissolved in deionized water to obtain a precipitant solution. The mixed metal ion solution was first poured into the beaker containing the SiO2 suspension and ultrasonically mixed, then the K2CO3 solution was slowly added and the pH was controlled at 9, and after stirring for 5 h, the filter cake was washed with deionized water until the pH was 7, then it was placed in an 80°C oven to dry overnight, and the obtained solid was calcined in a muffle furnace at 480°C for 4 h to obtain the catalyst Cu-Fe / SiO2.

[0065] The amine reaction process and reaction conditions in this embodiment were the same as in Example 1, and the reaction results are shown in Table 9.

[0066] Table 9 Reaction conditions and reaction results of Comparative Example 1

[0067] Reaction temperature / °C airspeed / h -1 ]] Pressure / MPa Hydrogen flow rate / (L / h) Reaction conversion rate X / % Reaction selectivity S / % 130 0.3 6.0 1.0 68.56 75.60 150 0.5 4.5 7.5 73.23 72.85 170 0.8 2.5 12.5 84.37 80.29 190 1.0 1.0 20.0 90.63 85.37

[0068] Comparative Example 2

[0069] A commercially available Raney Ni catalyst was used to carry out the long-chain diol hydrogenation reaction, wherein the reaction process and reaction conditions were the same as in Example 2, and the reaction results are shown in Table 10.

[0070] Table 10 Reaction conditions and reaction results of Comparative Example 2

[0071] Reaction temperature / °C airspeed / h -1 ]] Pressure / MPa Hydrogen flow rate / (L / h) Reaction conversion rate X / % Reaction selectivity S / % Reaction temperature / °C Pressure / MPa Hydrogen flow rate / (L / h) Reaction conversion rate X / % Reaction selectivity S / % 140 0.3 5.0 3.0 70.35 78.48 160 0.5 4.0 7.5 75.48 75.36 180 0.8 2.5 15.0 82.69 83.59 200 1.0 1.5 18.5 88.43 88.62

Claims

1. A process for catalyzing the hydrogenative amination of long-chain diols using a highly efficient MOF catalyst, characterized in that The method uses Cu / Fe-Mo2C as a catalyst, wherein Mo2C is a carrier, Cu is an active component, and Fe is an additive, and the specific reaction process is as follows: after the catalyst is loaded into a fixed bed reactor, hydrogen is fed into the fixed bed reactor, the catalyst is reduced at 250-300 DEG C for 6-8 h, and after reduction, the temperature is lowered to the amination reaction temperature, the raw material long-chain dihydric alcohol is dissolved in the solvent tetrahydrofuran to prepare a 10wt%-30wt% solution, then the foregoing solution is mixed with liquid ammonia in a certain proportion, and the mixture is uniformly fed into the reactor by a raw material pump, and the reaction parameters are adjusted to perform amination reaction.

2. The method of claim 1, wherein The long-chain diol has a structural formula of: OH—CH2—(CH2) n —CH2—OH, wherein 8≤n≤12.

3. The method of claim 1, wherein The reaction parameters are as follows: the molar ratio of raw material alcohol to liquid ammonia is 1:2-1:12, the reaction temperature is 130-200℃, the hydrogen pressure is 1-6 MPa, the volume space velocity is 0.2-1.5 h -1 , and the hydrogen flow rate is 1-20 L / h.

4. The method according to claim 1 or 2 or 3, characterized in that The preparation method of the catalyst Cu / Fe-Mo2C comprises the following steps: (1) A corresponding amount of phosphomolybdic acid H3PO4·12MoO3, trimesic acid, L-glutamic acid, and copper acetate monohydrate Cu(CH3CO2)2·H2O are dissolved in a 10wt% ethanol aqueous solution, and stirred at room temperature until mixed uniformly; (2) The mixed solution is centrifuged 3 times, washed to obtain a solid precipitate, and then placed in an oven for drying, and the dried solid is placed in a tube furnace in an Ar atmosphere, the gas flow rate is 20-100 L / h, the temperature in the furnace is controlled to be raised to a certain temperature at a rate of 5 DEG C / min, and the black Cu@Mo2C powder is obtained by heat treatment; (3) The Cu@Mo2C is ultrasonically dispersed in deionized water, a certain amount of iron salt is added, and the mixed solution is stirred at 40 DEG C until mixed uniformly, then NaCl solution is added and the stirring is continued at 40 DEG C for 12 h to remove the residue, then the obtained solution is separated by suction filtration, and the separated solid is washed repeatedly with deionized water and dried to obtain the deposit Cu / Fe-Mo2C.

5. The method of claim 1, wherein The molar ratio of the loaded metals Fe and Cu in the catalyst Cu / Fe-Mo2C is 1:1-1:

5.

6. The method for preparing the catalyst Cu / Fe-Mo2C according to claim 4, characterized in that, The molar ratio of copper acetate monohydrate Cu(CH3CO2)2·H2O, L-glutamic acid, H3PO4·12MoO3, and trimesic acid in step (1) is 1:(0.2-0.6):(0.1-0.4):(0.3-0.9).

7. The process for the preparation of the catalyst Cu / Fe-Mo2C according to claim 4, characterized in that, The drying temperature in step (2) is 70-120 DEG C.

8. The method for preparing the catalyst Cu / Fe-Mo2C according to claim 4, characterized in that, The temperature in the tube furnace in step (2) is 400-800 DEG C.

9. The method for preparing the catalyst Cu / Fe-Mo2C according to claim 4, characterized in that, The drying temperature in step (3) is 60-120 DEG C.

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