CoZn-coated NMC bimetallic catalyst and preparation method and application thereof

Abstract

The invention provides a CoZn-coated NMC bimetallic catalyst and a preparation method and application thereof, the preparation method of the catalyst is as follows: gallic acid, urea, cobalt salt and zinc salt are used as raw materials, an amphiphilic block copolymer Pluronic F127 is used as a soft template, a catalyst precursor is prepared by a solvent evaporation induced self-assembly method, and then the CoZn-coated NMC bimetallic catalyst is prepared by high-temperature pyrolysis at 600-800 DEG C. The catalyst is applied to preparation of furanamine through reductive amination of furanaldehyde, and the furanamine yield can reach 98% or above at most. The method is simple to operate, good in catalyst activity, high in selectivity, good in stability, low in cost and suitable for industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst preparation, and particularly relates to a CoZn@NMC bimetallic catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Fossil resources such as coal, petroleum, and natural gas have always been the main sources for the production of biofuels and industrial chemicals. However, their limitedness and carbon dioxide emissions limit the extensive use of fossil resources. Non-edible biomass such as lignocellulose (composed of cellulose, hemicellulose, and lignin) has attracted people's attention due to its advantages such as rich resources, sustainability, and low cost. Based on the hydrolysis of cellulose and hemicellulose, the conversion to second-generation biofuels and platform molecules can be achieved, including monosaccharides (glucose and xylose), polyols (glycerol, arabinitol, and sorbitol), furans (furfural and 5-hydroxymethylfurfural), and acids (2,5-furandicarboxylic acid, glutaric acid, and lactic acid), etc. Among them, furfural stands out as a bridge connecting biomass resources and biofuels and industrial chemicals. Through the reductive amination of furfural and its derivatives (furfural aldehydes) with ammonia, valuable amine derivatives including furanamines and their derivatives can be synthesized, which are widely used in the production of pharmaceuticals, pesticides, synthetic resins, and agrochemicals.

[0003] Currently, catalysts are required for the reductive amination of furfural aldehydes to prepare furanamines. However, most of them are noble metal catalysts, and the catalyst cost is high; in addition, most of the reaction conditions are relatively harsh, and the reaction system is not green and environmentally friendly; therefore, it is crucial to develop high-performance non-noble metal catalysts to achieve the reductive amination of furfural aldehydes to prepare furanamines under mild and green conditions. Summary of the Invention

[0004] The purpose of the present invention is to provide a CoZn@NMC bimetallic catalyst, a preparation method thereof, and to apply it to the reductive amination of furfural aldehydes to prepare furanamines. The catalyst prepared by the method of the present invention has good activity, high selectivity, good stability, and low cost. The highest yield of the furanamine prepared by the present invention can reach 98%, the reaction conditions are mild, the process operation is simple, and it is suitable for industrial production.

[0005] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0006] A preparation method of a CoZn@NMC bimetallic catalyst, comprising the following steps:

[0007] Step 1: Dissolve gallic acid, urea, and F127 (amphiphilic block copolymer Pluronic) in absolute ethanol, dropwise add an absolute ethanol solution of cobalt salt and zinc salt, perform solvent evaporation-induced self-assembly, then transfer the mixed solution to a polytetrafluoroethylene petri dish, evaporate at room temperature, and then heat in an oven, and cool to obtain a catalyst precursor;

[0008] Step 2: Pyrolyze the above catalyst precursor in an inert gas atmosphere and cool to obtain the CoZn@NMC bimetallic catalyst.

[0009] Furthermore, the mass ratio of gallic acid: urea: F127: cobalt salt and zinc salt is 1: 0.2-0.5: 1: 0.5.

[0010] The cobalt salt is cobalt nitrate, cobalt acetate or cobalt chloride, and the zinc salt is the same salt as the cobalt salt used.

[0011] Furthermore, the mass ratio of cobalt salt: zinc salt is 1: 0.3-10.

[0012] Furthermore, the temperature of the solvent evaporation-induced self-assembly in Step 1 is room temperature, and the time is 0.5-2 h.

[0013] Furthermore, the evaporation time at room temperature in Step 1 is 6-12 h.

[0014] Furthermore, the heating temperature in the oven in Step 1 is 90-120 °C, and the time is 24 h.

[0015] Furthermore, the pyrolysis temperature in Step 2 is 600-800 °C, and the pyrolysis time is 2-4 h.

[0016] A CoZn@NMC bimetallic catalyst prepared by the above preparation method.

[0017] An application of a CoZn@NMC bimetallic catalyst in the reaction of reductive amination of furfural to furanamine. The specific implementation process is as follows: Using the furfural shown in Formula I as the raw material, water as the reaction solvent, under the action of the CoZn@NMC bimetallic catalyst, carry out a reductive amination reaction with a nitrogen source in a hydrogen atmosphere, and prepare the furanamine shown in Formula II after post-treatment of the reaction solution. The reaction formula is as follows:

[0018]

[0019] In the formula, the substituent R is H, methyl, methoxy or hydroxymethyl.

[0020] Furthermore, the nitrogen source is hydrazine hydrate, ammonia water or ammonia gas; when the nitrogen source is hydrazine hydrate or ammonia water, its molar amount used is 3-4 times the molar amount of furfural, and when the nitrogen source is ammonia gas, the pressure is 0.1 MPa.

[0021] The reaction conditions are: hydrogen pressure is 1-2 MPa, reaction temperature is 90-110 °C, and reaction time is 2-4 h.

[0022] The mass dosage of the CoZn@NMC bimetallic catalyst is 0.1-0.8 times the mass of furfural.

[0023] The volume of water used is 20 - 60 mL / g based on the mass of furfuraldehyde;

[0024] The post - treatment method of the reaction solution is as follows: after the reaction is completed, the reaction solution is filtered, and the filtrate is distilled under reduced pressure to remove the solvent to obtain furfurylamine.

[0025] The beneficial effects of the present invention are as follows: the CoZn@NMC bimetallic catalyst provided by the present invention shows high activity and high selectivity in the reductive amination of furfuraldehyde to prepare furfurylamine. The highest yield of furfurylamine can reach more than 98%, greatly improving the yield of furfurylamine. The catalyst prepared by the method of the present invention has good stability, low cost, mild reaction conditions, and simple process operation. Description of the Drawings

[0026] Figure 1 is the transmission electron microscopy (TEM) image of the Co 1 Zn 1 @NMC - 700 catalyst prepared in Example 1 of the present invention;

[0027] Figure 2 is the TEM image of the Co@NMC - 700 catalyst prepared in Example 2 of the present invention.

[0028] Figure 3 is the TEM image of the Co@MC - 700 catalyst prepared in Example 3 of the present invention. Detailed Embodiments

[0029] The present invention will be further described below in conjunction with specific embodiments and the accompanying drawings of the specification, but the protection scope of the present invention is not limited thereto.

[0030] A series of CoZn@NMC catalysts with different metal ratios were prepared by solvent - evaporation - induced self - assembly combined with high - temperature pyrolysis method and applied to the following examples.

[0031] Example 1

[0032] Co 1 Zn 1 @NMC - 700 catalyst preparation: Dissolve 1 g of gallic acid and 0.25 g of urea in 20 mL of absolute ethanol, denoted as solution A; dissolve 1.0 g of F127 in 20 mL of absolute ethanol, denoted as solution B. Slowly add solution A to solution B and stir for 30 min. Then, add 0.25 g of Co(NO 3 ) 3 ·6H 2 O and 0.25 g of Zn(NO 3 ) 2 ·6H 2O was dissolved in 10 mL of absolute ethanol and then slowly added to the mixed solution of A and B. The obtained mixture was further stirred at room temperature for 30 min for solvent evaporation-induced self-assembly. The resulting solution was transferred to a polytetrafluoroethylene petri dish and evaporated at room temperature for 10 h, and then heated in an oven at 100 °C for 24 h. Finally, the dried solid was placed in a tubular furnace and heated from room temperature to 700 °C at a heating rate of 1 °C min -1 and carbonized in an N 2 atmosphere for 2 h to obtain the Co 1 Zn 1 @NMC-700 catalyst. The Co 1 Zn 1 @NMC-700 catalyst was detected by transmission electron microscopy, and the TEM image of the Co 1 Zn 1 @NMC-700 catalyst was obtained, as shown in Figure 1 Figure.

[0033] Example 2

[0034] Preparation of Co@NMC-700 catalyst: 1 g of gallic acid and 0.25 g of urea were dissolved in 20 mL of absolute ethanol, denoted as solution A; 1.0 g of F127 was dissolved in 20 mL of absolute ethanol, denoted as solution B. Solution A was slowly added to solution B and stirred for 30 min. Then, 0.5 g of Co(NO 3 ) 3 ·6H 2 O was dissolved in 10 mL of absolute ethanol and then slowly added to the mixed solution of A and B. The obtained mixture was further stirred at room temperature for 30 min. The resulting solution was transferred to a polytetrafluoroethylene petri dish and evaporated at room temperature for 10 h, and then heated in an oven at 100 °C for 24 h. Finally, the dried solid was placed in a tubular furnace and heated from room temperature to 700 °C at a heating rate of 1 °C min -1 and carbonized in an N 2 atmosphere for 2 h to obtain the Co@NMC-700 catalyst. The Co@NMC-700 catalyst was detected by transmission electron microscopy, and the TEM image of the Co@NMC-700 catalyst was obtained, as shown in Figure 2 Figure.

[0035] Example 3

[0036] Preparation of Co@MC-700 catalyst: 1 g of gallic acid was dissolved in 20 mL of absolute ethanol, denoted as solution A; 1.0 g of F127 was dissolved in 20 mL of absolute ethanol, denoted as solution B. Solution A was slowly added to solution B and stirred for 30 min. Then, 0.5 g of Co(NO 3 ) 3 ·6H 2O was dissolved in 10 mL of absolute ethanol and then slowly added to the mixed solution of A and B. The resulting mixture was further stirred at room temperature for 30 min. The obtained solution was transferred to a polytetrafluoroethylene petri dish, evaporated at room temperature for 10 h, and then heated in an oven at 100 °C for 24 h. Finally, the dried solid was placed in a tubular furnace and heated from room temperature to 700 °C at a heating rate of 1 °C min -1 to carbonize in an N 2 atmosphere for 2 h to obtain the Co@MC-700 catalyst. The Co@MC-700 catalyst was detected by transmission electron microscopy to obtain the TEM image of the Co@MC-700 catalyst, as shown in Figure 3 .

[0037] The TEM images of the above three catalysts were compared. Figure 3 The average particle size of Co nanoparticles in Figure 2 was 7.8 nm, and the particle size distribution range was 3 - 23 nm. The size distribution of metal particles was relatively uneven, and obvious agglomeration phenomenon existed. Figure 1 The average particle size of Co nanoparticles in

[0038] Example 4

[0039] Co 1 Zn 3 @NMC-700 catalyst preparation: 1 g of gallic acid and 0.25 g of urea were dissolved in 20 mL of absolute ethanol, denoted as solution A; 1.0 g of F127 was dissolved in 20 mL of absolute ethanol, denoted as solution B. Solution A was slowly added to solution B and stirred for 30 min. Then, 0.125 g of Co(NO 3 ) 3 ·6H 2 O and 0.375 g of Zn(NO 3 ) 2 ·6H 2 O were dissolved in 10 mL of absolute ethanol and then slowly added to the mixed solution of A and B. The resulting mixture was further stirred at room temperature for 30 min for solvent evaporation-induced self-assembly. The obtained solution was transferred to a polytetrafluoroethylene petri dish, evaporated at room temperature for 10 h, and then heated in an oven at 100 °C for 24 h. Finally, the dried solid was placed in a tubular furnace and heated at a rate of 1 °C min-1 The heating rate is increased from room temperature to 700 °C and carbonized in N 2 atmosphere for 2 h to obtain Co 1 Zn 3 @NMC catalyst.

[0040] Example 5

[0041] Co 3 Zn 1 Preparation of Co 3 Zn 3 @NMC-700 catalyst: Dissolve 1 g of gallic acid and 0.25 g of urea in 20 mL of absolute ethanol, denoted as solution A; dissolve 1.0 g of F127 in 20 mL of absolute ethanol, denoted as solution B. Slowly add solution A to solution B and stir for 30 min. Then, dissolve 0.375 g of Co(NO 2 ) 3 ·6H 2 O and 0.125 g of Zn(NO 3 ) 2 ·6H 2 O in 10 mL of absolute ethanol, and then slowly add it to the mixed solution of A and B. The obtained mixture is further stirred at room temperature for 30 min for solvent evaporation-induced self-assembly. The resulting solution is transferred to a polytetrafluoroethylene petri dish, evaporated at room temperature for 10 h, and then heated in an oven at 100 °C for 24 h. Finally, the dried solid is placed in a tube furnace and heated from room temperature to 700 °C at a heating rate of 1 °C min -1 in N 2 atmosphere for 2 h to obtain Co 3 Zn 1 @NMC catalyst.

[0042] Example 6

[0043] Preparation of Co 1 Zn 1 @NMC-600 catalyst: Dissolve 1 g of gallic acid and 0.25 g of urea in 20 mL of absolute ethanol, denoted as solution A; dissolve 1.0 g of F127 in 20 mL of absolute ethanol, denoted as solution B. Slowly add solution A to solution B and stir for 30 min. Then, dissolve 0.25 g of Co(NO 3 ) 3 ·6H 2 O and 0.25 g of Zn(NO 3 ) 2 ·6H 2O was dissolved in 10 mL of absolute ethanol and then slowly added to the mixed solution of A and B. The obtained mixture was further stirred at room temperature for 30 min for solvent evaporation-induced self-assembly. The resulting solution was transferred to a polytetrafluoroethylene petri dish and evaporated at room temperature for 10 h, and then heated in an oven at 100 °C for 24 h. Finally, the dried solid was placed in a tube furnace and heated from room temperature to 600 °C at a heating rate of 1 °C min -1 and carbonized in an N 2 atmosphere for 2 h to obtain the Co 1 Zn 1 @NMC-600 catalyst.

[0044] Example 7

[0045] Preparation of Co 1 Zn 1 @NMC-800 catalyst: 1 g of gallic acid and 0.25 g of urea were dissolved in 20 mL of absolute ethanol, denoted as solution A; 1.0 g of F127 was dissolved in 20 mL of absolute ethanol, denoted as solution B. Solution A was slowly added to solution B and stirred for 30 min. Then, 0.25 g of Co(NO 3 ) 3 ·6H 2 O and 0.25 g of Zn(NO 3 ) 2 ·6H 2 O were dissolved in 10 mL of absolute ethanol and then slowly added to the mixed solution of A and B. The obtained mixture was further stirred at room temperature for 30 min for solvent evaporation-induced self-assembly. The resulting solution was transferred to a polytetrafluoroethylene petri dish and evaporated at room temperature for 10 h, and then heated in an oven at 100 °C for 24 h. Finally, the dried solid was placed in a tube furnace and heated from room temperature to 800 °C at a heating rate of 1 °C min -1 and carbonized in an N 2 atmosphere for 2 h to obtain the Co 1 Zn 1 @NMC-800 catalyst.

[0046] Example 8

[0047] Take 2 mmol of furfural and 8 mmol of N 2 H 4 ·H 2 O and place them in a beaker, add 10 mL of water to dissolve, add the solution to a 25 mL high-pressure reactor, and add 0.1 g of Co 1 Zn 1The @NMC-800 catalyst was purged with nitrogen three times and then hydrogen at 1.5 MPa was introduced. The reaction temperature was 100 °C and the reaction was carried out for 3 h. After the reaction ended, the reaction solution was filtered, and the solvent was removed by vacuum distillation of the filtrate to obtain furfurylamine. The conversion rate of furfural was 100%, and the yield of furfurylamine was 96.3%.

[0048] Example 9

[0049] Take 2 mmol of furfural and 8 mmol of N 2 H 4 ·H 2 O and place them in a beaker. Add 10 mL of water to dissolve, add the solution to a 25 mL high-pressure reactor, and add 0.1 g of Co 1 Zn 1 The @NMC-800 catalyst was purged with nitrogen three times and then hydrogen at 1.5 MPa was introduced. The reaction temperature was 100 °C and the reaction was carried out for 2 h. After the reaction ended, the reaction solution was filtered, and the solvent was removed by vacuum distillation of the filtrate to obtain furfurylamine. The conversion rate of furfural was 100%, and the yield of furfurylamine was 86.9%.

[0050] Example 10

[0051] Take 2 mmol of furfural and 8 mmol of NH 3 ·H 2 O and place them in a beaker. Add 10 mL of water to dissolve, add the solution to a 25 mL high-pressure reactor, and add 0.1 g of Co 1 Zn 1 The @NMC-800 catalyst was purged with nitrogen three times and then hydrogen at 2 MPa was introduced. The reaction temperature was 100 °C and the reaction was carried out for 3 h. After the reaction ended, the reaction solution was filtered, and the solvent was removed by vacuum distillation of the filtrate to obtain furfurylamine. The conversion rate of furfural was 100%, and the yield of furfurylamine was 91.6%.

[0052] Example 11

[0053] Take 2 mmol of furfural and 8 mmol of N 2 H 4 ·H 2 O and place them in a beaker. Add 10 mL of water to dissolve, add the solution to a 25 mL high-pressure reactor, and add 0.06 g of Co 1 Zn 1 The @NMC-800 catalyst was purged with nitrogen three times and then hydrogen at 1.5 MPa was introduced. The reaction temperature was 100 °C and the reaction was carried out for 3 h. After the reaction ended, the reaction solution was filtered, and the solvent was removed by vacuum distillation of the filtrate to obtain furfurylamine. The conversion rate of furfural was 100%, and the yield of furfurylamine was 82.5%.

[0054] Example 12

[0055] Take 2 mmol of furfural and place it in a beaker. Add 10 mL of water to dissolve it. Then add the solution to a 25 mL high-pressure reactor and add 0.1 g of Co 1 Zn 1 @NMC-800 catalyst. After purging with nitrogen three times, introduce 1.5 MPa of hydrogen and 0.1 MPa of ammonia. React at 100 °C for 3 h. After the reaction is completed, filter the reaction solution, and distill off the solvent under reduced pressure to obtain furfurylamine. The conversion rate of furfural is 100%, and the yield of furfurylamine is 92.7%.

[0056] Example 13

[0057] Take 2 mmol of furfural and 6 mmol of N 2 H 4 ·H 2 O and place them in a beaker. Add 10 mL of water to dissolve them. Then add the solution to a 25 mL high-pressure reactor and add 0.1 g of Co 1 Zn 1 @NMC-800 catalyst. After purging with nitrogen three times, introduce 1.5 MPa of hydrogen. React at 100 °C for 3 h. After the reaction is completed, filter the reaction solution, and distill off the solvent under reduced pressure to obtain furfurylamine. The conversion rate of furfural is 100%, and the yield of furfurylamine is 95.8%.

[0058] Example 14

[0059] Take 2 mmol of furfural and 8 mmol of N 2 H 4 ·H 2 O and place them in a beaker. Add 10 mL of water to dissolve them. Then add the solution to a 25 mL high-pressure reactor and add 0.1 g of Co 1 Zn 3 @NMC-800 catalyst. After purging with nitrogen three times, introduce 1.5 MPa of hydrogen. React at 100 °C for 3 h. After the reaction is completed, filter the reaction solution, and distill off the solvent under reduced pressure to obtain furfurylamine. The conversion rate of furfural is 100%, and the yield of furfurylamine is 77.3%.

[0060] Comparing Comparative Example 8 and Example 14, it is found that Co 1 Zn 1 @NMC-800 exhibits higher catalytic activity than Co 1 Zn 3 @NMC-800. This is mainly because Co in the CoZn@NMC catalyst mainly exists in the 0 valence state, and Zn mainly exists in the oxidized state. Therefore, Co is the main catalytic active site in the catalyst. Due to the higher Co content in Co 1 Zn 1 @NMC-800, more catalytic active sites are provided. Therefore, the yield of furfurylamine is effectively increased.

[0061] Example 15

[0062] Take 2 mmol of furfural and 8 mmol of N 2 H 4 ·H 2 O and place them in a beaker. Add 10 mL of water to dissolve. Add the solution to a 25 mL high-pressure reactor, and add 0.1 g of Co 1 Zn 3 @NMC-700 catalyst. After purging with nitrogen three times, introduce 1.5 MPa of hydrogen. The reaction temperature is 100 °C, and the reaction lasts for 3 h. After the reaction is completed, filter the reaction solution, and distill off the solvent under reduced pressure to obtain furfurylamine. The conversion rate of furfural is 100%, and the yield of furfurylamine is 85.4%.

[0063] Example 16

[0064] Take 2 mmol of furfural and 8 mmol of N 2 H 4 ·H 2 O and place them in a beaker. Add 10 mL of water to dissolve. Add the solution to a 25 mL high-pressure reactor, and add 0.1 g of Co 1 Zn 3 @NMC-600 catalyst. After purging with nitrogen three times, introduce 1.5 MPa of hydrogen. The reaction temperature is 100 °C, and the reaction lasts for 3 h. After the reaction is completed, filter the reaction solution, and distill off the solvent under reduced pressure to obtain furfurylamine. The conversion rate of furfural is 100%, and the yield of furfurylamine is 96.4%.

[0065] Example 17

[0066] Take 2 mmol of furfural and 8 mmol of N 2 H 4 ·H 2 O and place them in a beaker. Add 10 mL of water to dissolve. Add the solution to a 25 mL high-pressure reactor, and add 0.1 g of Co 3 Zn 1 @NMC-700 catalyst. After purging with nitrogen three times, introduce 1.5 MPa of hydrogen. The reaction temperature is 100 °C, and the reaction lasts for 3 h. After the reaction is completed, filter the reaction solution, and distill off the solvent under reduced pressure to obtain furfurylamine. The conversion rate of furfural is 100%, and the yield of furfurylamine is 89.1%.

[0067] Examples 18 - 19:

[0068] Other operations are the same as in Example 8, but change the calcination temperature of the Co 1 Zn 1 @NMC catalyst (i.e., use the catalysts prepared in Examples 1, 6, and 7 for the experiment), and obtain the following reaction results (Table 1):

[0069] Summary Table of the Influence of Catalysts Obtained at Different Calcination Temperatures on the Yield of Furfural Amine

[0070]

[0071] Examples 20 - 22:

[0072] Other operations were the same as in Example 19. By changing the number of times the catalyst was reused, the following reaction results were obtained (Table 2):

[0073] Table 2 Co 1 Zn 1 Summary Table of the Reusability Effect of @NMC-700 Catalyst

[0074]

[0075] Example 23

[0076] Take 2 mmol of furfural and 8 mmol of N 2 H 4 ·H 2 O and place them in a beaker. Add 10 mL of water to dissolve. Transfer the solution to a 25 mL high-pressure reactor. Add 0.1 g of Co@NMC-700 catalyst. After purging with nitrogen three times, introduce 1.5 MPa of hydrogen. React at 100 °C for 3 h. After the reaction, filter the reaction solution. Distill off the solvent under reduced pressure from the filtrate to obtain furfural amine. The conversion rate of furfural is 100%, and the yield of furfural amine is 85.9%.

[0077] Examples 24 - 26

[0078] Other operations were the same as in Example 23. By changing the number of times the catalyst was reused, the following reaction results were obtained (Table 3):

[0079] Table 3 Summary Table of the Reusability Effect of Co@NMC-700 Catalyst

[0080]

[0081] Example 27

[0082] Take 2 mmol of furfural and 8 mmol of N 2 H 4 ·H 2 O and place them in a beaker. Add 10 mL of water to dissolve. Transfer the solution to a 25 mL high-pressure reactor. Add 0.1 g of Co@MC-700 catalyst. After purging with nitrogen three times, introduce 1.5 MPa of hydrogen. React at 100 °C for 3 h. After the reaction, filter the reaction solution. Distill off the solvent under reduced pressure from the filtrate to obtain furfural amine. The conversion rate of furfural is 100%, and the yield of furfural amine is 77.1%.

[0083] Examples 28 - 30

[0084] Other operations were the same as in Example 27. By changing the number of times the catalyst was reused, the following reaction results were obtained (Table 4):

[0085] Table 4 Summary of the reuse effect of Co@MC - 700 catalyst

[0086]

[0087] Comparing with Comparative Examples 19 - 30, it can be seen that introducing the second metal Zn and doping N element effectively improved the selectivity, stability of the CoZn@NMC catalyst and the yield of furfurylamine.

[0088] Examples 31 - 33:

[0089] Other operations were the same as in Example 19. By changing the type of furfural, the following reaction results were obtained (Table 5):

[0090] Table 5 Summary of the reaction yields of furfural with different substituents

[0091]

[0092] The content described in this specification is only a list of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments.

Claims

1. A method for preparing a CoZn@NMC bimetallic catalyst, characterized in that: The following steps are involved: Step 1: Dissolve gallic acid, urea and F127 in anhydrous ethanol, drop anhydrous ethanol solution of cobalt salt and zinc salt into it, perform solvent evaporation to induce self-assembly, then transfer the mixed solution to a polytetrafluoroethylene culture dish, evaporate at room temperature, heat in an oven, and cool to obtain a catalyst precursor; Step 2: Pyrolyze the catalyst precursor in an inert gas atmosphere and cool it to obtain the CoZn@NMC bimetallic catalyst.

2. The method for preparing a CoZn@NMC bimetallic catalyst according to claim 1, characterized in that: Gallic acid: The mass ratio of urea: F127: cobalt salt and zinc salt is 1: 0.2 to 0.5: 1: 0.

5. The cobalt salt is cobalt nitrate, cobalt acetate or cobalt chloride, and the zinc salt is the same salt as the cobalt salt.

3. The method for preparing a CoZn@NMC bimetallic catalyst according to claim 2, characterized in that: The mass ratio of cobalt salt: zinc salt is 1:0.3~10.

4. The method for preparing a CoZn@NMC bimetallic catalyst according to claim 1, characterized in that: The temperature for the solvent volatilization-induced self-assembly in step 1 is room temperature and the time is 0.5 to 2 hours.

5. The method for preparing a CoZn@NMC bimetallic catalyst according to claim 1, characterized in that: The evaporation time at room temperature in step 1 is 6 to 12 hours.

6. The method for preparing a CoZn@NMC bimetallic catalyst according to claim 1, characterized in that: The heating temperature in the oven described in step 1 is 90-120° C. and the heating time is 24 hours.

7. The method for preparing a CoZn@NMC bimetallic catalyst according to claim 1, characterized in that: The pyrolysis temperature in step 2 is 600-800° C., and the pyrolysis time is 2-4 hours.

8. A CoZn@NMC bimetallic catalyst prepared by any preparation method as claimed in claims 1-7.

9. Use of the CoZn@NMC bimetallic catalyst as claimed in claim 8 in the reductive amination of furanaldehyde to produce furanamine, characterized in that: The specific implementation process is as follows: furan aldehyde shown in formula I is used as a raw material, water is used as a reaction solvent, and a reductive amination reaction is carried out with a nitrogen source in a hydrogen atmosphere under the action of a CoZn@NMC bimetallic catalyst, and the reaction solution is post-treated to prepare furan amine shown in formula II, and the reaction formula is as follows: In the formula, the substituent R is H, methyl, methoxy or hydroxymethyl.

10. The use according to claim 9, characterized in that The nitrogen source is hydrazine hydrate, ammonia water or ammonia gas; when the nitrogen source is hydrazine hydrate or ammonia water, the molar amount is 3 to 4 times the molar amount of furanaldehyde; when the nitrogen source is ammonia gas, the pressure is 0.1 MPa; The reaction conditions are: hydrogen pressure of 1-2 MPa, reaction temperature of 90-110°C, and reaction time of 2-4 h; The mass dosage of CoZn@NMC bimetallic catalyst is 0.1 to 0.8 times the mass of furanaldehyde. The volume amount of water used is 20-60 mL / g based on the mass of furanaldehyde; The post-treatment method of the reaction liquid is as follows: after the reaction is completed, the reaction liquid is filtered, and the filtrate is distilled under reduced pressure to remove the solvent to obtain furanamine.

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