Nitrogen-doped carbon nickel-based material, preparation method thereof and method for preparing 2, 5-furandimethylamine by catalyzing 5-hydroxymethylfurfural

Abstract

The invention belongs to the technical field of organic catalysis, and particularly relates to a nitrogen-doped carbon nickel-based material, a preparation method of the nitrogen-doped carbon nickel-based material and a method for preparing 2, 5-furan dimethylamine by catalyzing 5-hydroxymethylfurfural. The nitrogen-doped carbon nickel-based material is formed by loading metallic nickel on a nitrogen-doped carbon carrier, the mass percentage content of the metallic nickel in the nitrogen-doped carbon nickel-based material is 3-20%, a water-soluble nickel salt and 2-methylimidazole are dissolved in methanol for a solvothermal reaction, then turbid liquid is collected and transferred into a centrifugal tube for centrifugation, and the nitrogen-doped carbon nickel-based material is obtained. And washing and drying the obtained solid, and sequentially calcining and reducing and baking to obtain the catalyst. The nitrogen-doped carbon nickel-based material comprises high-dispersion nickel nanoparticles and a porous layered structure, has high conversion rate and selectivity in a reaction for preparing 2, 5-furan dimethylamine from 5-hydroxymethylfurfural, and completely avoids using precious metals and carriers with high cost, and the preparation method is simple to operate and low in cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic catalysis, and particularly relates to a nickel-based material of nitrogen-doped carbon, a preparation method thereof, and a method for catalyzing 5-hydroxymethylfurfural to prepare 2,5-furandimethylamine. Background Art

[0002] As the only renewable carbon source, the conversion of biomass into high-value chemicals can not only reduce the dependence on fossil resources but also significantly reduce greenhouse gas emissions. Among numerous biomass-derived platform compounds, 5-hydroxymethylfurfural (HMF) has attracted much attention due to its unique molecular structure. The HMF molecule contains active hydroxyl and aldehyde groups, which can be converted into various high-value chemicals through oxidation, hydrogenation, amination and other reactions, such as 2,5-furandicarboxylic acid (FDCA), 2,5-dimethylfuran (DMF), and 2,5-furandimethylamine (BAMF). Among them, BAMF, as a key monomer of high-performance polymers such as polyamides and polyimides, shows broad application prospects in the fields of high-temperature resistant materials, biodegradable plastics, and pharmaceutical synthesis. However, the reductive amination reaction of HMF faces two core challenges: one is that the competitive conversion of hydroxyl and aldehyde groups during the reaction easily leads to the formation of by-products (such as furandimethanol, coupling products), reducing the selectivity of the target product; the other is that existing catalysts generally have problems such as easy inactivation of active sites, agglomeration of metal particles, and poor resistance to ammonia poisoning, seriously restricting the industrialization process of the reaction.

[0003] The efficient utilization of biomass resources is an important research direction in green chemistry. It is estimated that more than 200 billion tons of lignocellulosic biomass are generated globally every year, but its effective utilization rate is less than 5%. As a bridge connecting biomass and high-value chemicals, HMF is usually prepared by acid-catalyzed dehydration of cellulose or fructose. In recent years, researchers have achieved the efficient synthesis of HMF with a yield of over 70% by optimizing reaction media (such as ionic liquids, biphasic systems) and catalysts (such as solid acids, metal oxides). However, the further functionalization of HMF still faces technical bottlenecks. Taking reductive amination as an example, this reaction needs to be carried out under the coexistence of hydrogen and ammonia, and it is necessary to achieve the selective reduction of aldehyde groups while avoiding excessive hydrogenation of hydroxyl groups or intermolecular condensation. Therefore, the development of catalysts with high activity, high selectivity, and stability has become the research focus in this field.

[0004] Transition metal catalysts (such as Ni, Co, Fe) show the potential to replace noble metals in reactions such as hydrogenation and deoxygenation due to their low cost, abundant reserves, and tunable electronic structures. Nickel-based catalysts are widely used in reactions such as the conversion of HMF to 2,5-dimethylfuran (DMF) due to their excellent hydrogenation activity. However, in reductive amination reactions, nickel catalysts face two challenges: First, the strong adsorption of ammonia molecules on the metal surface may cause the active sites to be covered, leading to catalyst poisoning; Second, metal particles are prone to sintering under high-temperature reaction conditions, resulting in a decrease in specific surface area and a reduction in active sites. To overcome these problems, researchers have tried to load metal nanoparticles on porous supports (such as carbon materials, metal-organic framework derivatives) and use the confinement effect of the support to inhibit metal migration. For example, ZIF-8-derived nitrogen-doped carbon supports can enhance the metal-support interaction and improve the dispersion through the coordination of pyridine nitrogen with the metal. Another example is that nitrogen-doped carbon materials have become ideal supports for loading metal catalysts due to their unique electronic properties and surface chemical properties. The introduction of nitrogen atoms can not only regulate the electronic conductivity of the carbon support but also enhance the anchoring ability of metal particles by forming metal-N bonds and inhibit their aggregation. In addition, nitrogen doping can regulate the surface acidity and basicity of the support, thereby affecting the adsorption and activation paths of reactants. For example, pyridine nitrogen sites can enhance the adsorption of ammonia, while graphitic nitrogen is beneficial to the dissociation of hydrogen. However, too high nitrogen content may cause the collapse of the support structure, and too low nitrogen content cannot effectively disperse metal particles. However, nickel-based materials with nitrogen-doped carbon and their application in catalyzing the preparation of 2,5-furandiamine from 5-hydroxymethylfurfural have not been reported. Summary of the Invention

[0005] Aiming at the deficiencies of the existing methods, the present invention provides a nickel-based material with nitrogen-doped carbon, a preparation method thereof, and a method for catalyzing the preparation of 2,5-furandiamine from 5-hydroxymethylfurfural.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A nickel-based material with nitrogen-doped carbon, wherein the nickel-based material with nitrogen-doped carbon is composed of metallic nickel loaded on a nitrogen-doped carbon support, and the mass percentage content of metallic nickel in the nickel-based material with nitrogen-doped carbon is 3-20%.

[0008] A preparation method of a nickel-based material with nitrogen-doped carbon, comprising the following steps:

[0009] Dissolve a water-soluble nickel salt and 2-methylimidazole in methanol for a solvothermal reaction, then collect the suspension and transfer it to a centrifuge tube for centrifugation. After washing and drying the obtained solid, calcination and reduction baking are carried out in sequence to obtain the product.

[0010] Preferably, the molar ratio of the water-soluble nickel salt to 2-methylimidazole is 1:4-16.

[0011] Preferably, the water-soluble nickel salt is one or more of Ni(NO3)2·6H2O, Ni(NO3)2·3H2O, NiCl2, Ni(OH)2, and Ni(CH3COO)2.

[0012] Preferably, the solvothermal reaction conditions are: stirring reaction at 20 - 60 °C for 6 - 12 h.

[0013] Preferably, the calcination conditions are: calcining at 300 - 700 °C for 0.5 - 6 h under a nitrogen atmosphere; the reduction baking conditions are: roasting at 300 - 600 °C for 0.5 - 6 h under a hydrogen atmosphere.

[0014] A method for preparing 2,5 - furandicarboxamide from 5 - hydroxymethylfurfural catalyzed by a nickel - based material of nitrogen - doped carbon, comprising the following steps: adding 5 - hydroxymethylfurfural, the nickel - based material of nitrogen - doped carbon, and a solvent into a reactor, and reacting in a hydrogen and ammonia atmosphere to generate 2,5 - furandicarboxamide.

[0015] Preferably, the mass ratio of the nickel - based material of nitrogen - doped carbon to 5 - hydroxymethylfurfural is 1:2 - 10.

[0016] Preferably, the hydrogen pressure is 1 - 4 MPa, the ammonia pressure is 0.1 - 0.5 MPa, the reaction temperature is 120 - 160 °C, and the reaction time is 3 - 18 h.

[0017] Preferably, the solvent is one or more of tetrahydrofuran, 1,4 - dioxane, ethanol, methanol, and isopropanol.

[0018] The positive and beneficial effects of the present invention:

[0019] 1. The active ingredient of the nickel - based material of nitrogen - doped carbon of the present invention is mainly nickel particles, and the nickel particles are nanoscale particles, highly dispersed. The nickel - based material of nitrogen - doped carbon is a layered structure, with a specific surface area of 108.09 - 196.31 m 2 / g, a large specific surface area, a pore volume of 0.135 - 0.258 cm 2 / g, a large pore volume, and an average pore diameter of 7.61 - 9.99 nm, having a high catalytic efficiency for the preparation of 2,5 - furandicarboxamide from 5 - hydroxymethylfurfural.

[0020] 2. The nickel-based material of nitrogen-doped carbon in the present invention contains highly dispersed nano-nickel particles and a porous layered structure, and has a high conversion rate and selectivity for the reaction of preparing 2,5-furandicarboxamide from 5-hydroxymethylfurfural. Moreover, this nickel-based material of nitrogen-doped carbon completely avoids the use of precious metals and carriers with high costs. The preparation method is simple in operation and low in cost, which is conducive to large-scale production. During the process of catalyzing the reaction of preparing 2,5-furandicarboxamide from 5-hydroxymethylfurfural, the conditions are mild. The conversion rate of 5-hydroxymethylfurfural is as high as 100%, and the yield of 2,5-furandicarboxamide is as high as 89.97%. The catalytic efficiency is high and it can be recycled, thus providing a new way for directly catalytically producing 2,5-furandicarboxamide from 5-hydroxymethylfurfural biomass raw materials, being suitable for industrial production and having a very broad application prospect.

[0021] 3. The calcination conditions during the preparation of the nickel-based material of nitrogen-doped carbon in the present invention are as follows: under a nitrogen atmosphere, at a temperature of 300 - 700 °C, calcined for 0.5 - 6 h. The main purpose of calcination under a nitrogen atmosphere is to remove the organic precursor to form a porous structure, and at the same time control the metal skeleton from collapsing, so that a catalyst with a certain crystal form, crystal grain size, pore structure and specific surface area can be obtained. If the calcination temperature is too high, it will lead to sintering and collapse of the catalyst structure, damaging the physical properties such as the pore structure and pore volume of the catalyst. If the calcination temperature is too low, the organic precursor will not be removed sufficiently, and it is difficult to obtain a good crystal form and morphology of the metal oxide.

[0022] 4. The reduction roasting temperature during the preparation of the nickel-based material of nitrogen-doped carbon in the present invention is one of the important factors affecting the catalyst activity. If the reduction temperature is too high, it is easy to cause agglomeration of the active components in the catalyst, reducing the dispersion degree of the active metal particles, and thus affecting its catalytic performance. However, if the reduction temperature is too low, the active components cannot be reduced, and the catalyst has no hydrogenolysis ability. The reduction roasting conditions during the preparation of the nickel-based material of nitrogen-doped carbon in the present invention are as follows: under a hydrogen atmosphere, at 300 - 600 °C, roasted for 0.5 - 6 h to realize the activation process of the catalyst, which can greatly improve the catalytic activity and catalytic selectivity of the catalyst. Description of the Drawings

[0023] Figure 1 It is the SEM diagram of the nickel-based material of nitrogen-doped carbon in the present invention;

[0024] Figure 2 It is the nitrogen isothermal adsorption and desorption curve of the nickel-based material of nitrogen-doped carbon in the present invention;

[0025] Figure 3 It is the pore size distribution diagram of the nickel-based material of nitrogen-doped carbon in the present invention;

[0026] Figure 4 It is the XRD diagram of the nickel-based material of nitrogen-doped carbon prepared at different reduction temperatures. Detailed implementation manners

[0027] The present invention will be further described below in conjunction with some specific embodiments.

[0028] Preparation methods of nickel-based materials of nitrogen-doped carbon for Examples 1 to 18 include the following steps

[0029] Dissolve 18.0 mmol of Ni(NO3)2·6H2O and 2-methylimidazole in different molar ratios (the molar ratio of water-soluble nickel salt to 2-methylimidazole is 1:4 to 16) in 25 mL of methanol, stir at room temperature for 6 h, then collect the green suspension and transfer it to a centrifuge tube for centrifugation. Wash it with anhydrous ethanol multiple times until the washing liquid is clear. Put the washed solid into a vacuum oven and dry it at 80°C for 12 h to collect the green powder; grind the dried precursor, transfer it to a nitrogen tube furnace and calcine it at 500°C for 3 h. After calcination, grind the catalyst and put it into a hydrogen tube furnace for reduction at 400°C for 2 h. The obtained nickel-based material of nitrogen-doped carbon is named Ni-NC-X. The performance test results of the nickel-based material of nitrogen-doped carbon are shown in Table 2 and Figures 1-4 , where X represents the molar ratio of the amount of 2-methylimidazole to nickel nitrate hexahydrate.

[0030] Application of the above nickel-based material of nitrogen-doped carbon in the reaction of catalytically preparing 2,5-furandicarboxamide from 5-hydroxymethylfurfural, including: adding 5-hydroxymethylfurfural, the above nickel-based material of nitrogen-doped carbon and a solvent into a reactor, and reacting in an atmosphere of hydrogen and ammonia to generate 2,5-furandicarboxamide, which is described in detail as follows

[0031] Add 200 mg of 5-hydroxymethylfurfural, 100 mg of the nickel-based material of nitrogen-doped carbon prepared in any one of Examples 1 to 18, and 5 mL of a solvent into a reaction kettle. Sequentially fill in 0.1 to 0.5 MPa of ammonia gas and 1 to 4 MPa of hydrogen gas. Under stirring conditions, heat to 120 to 160°C and react for 3 h. Then cool, release the gas, and filter to separate the catalyst from the reaction solution. After diluting and fixing the concentration of the reaction solution with a solvent, analyze it by gas chromatography. The experimental conditions and results of Examples 1 to 18 are shown in Table 1.

[0032] Table 1 Reaction conditions and results of nickel-based materials of nitrogen-doped carbon in catalytically preparing 2,5-furandicarboxamide from 5-hydroxymethylfurfural

[0033]

[0034]

[0035] Table 2 Performance parameters of nickel-based materials of nitrogen-doped carbon

[0036]

[0037] The nickel-based material of nitrogen-doped carbon obtained by the above preparation method, and the SEM images of the nickel-based materials of nitrogen-doped carbon in Examples 1-4 are shown in Figure 1 , corresponding to Figure 1 a, b, c, d in Figure 1 . It can be seen that the nickel-based material of nitrogen-doped carbon of the present invention has a porous layered structure.

[0038] From Figures 2-3 and Table 2, it can be seen that the specific surface area of the layered nickel-based material of nitrogen-doped carbon of the present invention is 108.09-196.31 m 2 / g, with a large specific surface area, the pore volume is 0.135-0.258 cm 2 / g, with a large pore volume, and the average pore diameter is 7.61-9.99 nm, which is beneficial to the exertion of the catalyst activity.

[0039] From Table 1, it can be seen from Examples 1-4 that by changing the molar ratio of nickel nitrate hexahydrate to 2-methylimidazole in the preparation process of the nickel-based material of nitrogen-doped carbon of the present invention, the optimal molar ratio is 1:8.

[0040] It can be seen from Examples 2, 5-8 that in an atmosphere of 3 MPa hydrogen and 0.35 MPa ammonia, at a temperature of 80-160 °C, when catalyzing the reaction of 5-hydroxymethylfurfural to prepare 2,5-furandimethylamine for 3 h, the preferred reaction temperature of the nickel-based material of nitrogen-doped carbon of the present invention in the reaction of catalyzing 5-hydroxymethylfurfural to prepare 2,5-furandimethylamine is 120-160 °C, and the optimal reaction temperature is 140 °C.

[0041] It can be seen from Examples 2, 9-11 that by changing the hydrogen pressure in the reaction of 5-hydroxymethylfurfural to prepare 2,5-furandimethylamine of the present invention, the hydrogen pressure of the present invention is 1-4 MPa, and a high conversion rate of 5-hydroxymethylfurfural and a yield of 2,5-furandimethylamine can be achieved. The optimal hydrogen pressure in Example 2 is 3 MPa.

[0042] It can be seen from Examples 2, 12-16 that by changing the ammonia pressure in the reaction of 5-hydroxymethylfurfural to prepare 2,5-furandimethylamine of the present invention, the preferred ammonia pressure of the present invention is 0.1-0.5 MPa, and a high conversion rate of 5-hydroxymethylfurfural and a yield of 2,5-furandimethylamine can be achieved. The optimal ammonia pressure is 0.35 MPa.

[0043] It can be seen from Examples 2, 17-18 that by changing the solvent in the reaction of 5-hydroxymethylfurfural to prepare 2,5-furandimethylamine of the present invention, the catalytic effect is optimal with 1,4-dioxane as the solvent, followed by tetrahydrofuran, and toluene is relatively poor.

[0044] The XRD patterns of the nickel silicate catalysts prepared in Examples 1-4 are shown in Figure 4, the nitrogen-doped carbon nickel-based materials prepared in different proportions all have a C hump in front after reduction. The characteristic peaks of Ni (PDF#04-0850) appear at 44.5°, 51.8° and 76.4°, corresponding to the (111), (200) and (220) crystal planes of Ni, respectively, which proves that the nitrogen-doped carbon nickel-based materials are successfully prepared, and the loaded nickel is nano-scale particles and highly dispersed. At the same time, it is observed that with the increase of the ratio, the diffraction peak of Ni first weakens and then becomes stronger, indicating that the particle size of Ni first decreases and then increases, and is optimal when the nitrogen-doped carbon nickel-based material Ni-NC-8 in Example 2 is used, and the particle size of the nickel element is 7.4nm.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in the field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A nickel-based material of nitrogen-doped carbon, characterized in that, The nickel-based material of the nitrogen-doped carbon is composed of metallic nickel supported on a nitrogen-doped carbon carrier, and the mass percentage of the metallic nickel in the nickel-based material of the nitrogen-doped carbon is 3-20%.

2. A method for preparing a nickel-based material of nitrogen-doped carbon according to claim 1, characterized in that, It includes the following steps: Dissolve a water-soluble nickel salt and 2-methylimidazole in methanol for solvothermal reaction, then collect the suspension and transfer it to a centrifuge tube for centrifugation. After washing and drying the obtained solid, perform calcination and reduction baking in sequence to obtain the product.

3. The preparation method of the nickel-based material of nitrogen-doped carbon according to claim 2, characterized in that, The molar ratio of the water-soluble nickel salt to 2-methylimidazole is 1:4-16.

4. The preparation method of the nickel-based material of nitrogen-doped carbon according to claim 2, characterized in that, The water-soluble nickel salt is one or more of Ni(NO3)2·6H2O, Ni(NO3)2·3H2O, NiCl2, Ni(OH)2, and Ni(CH3COO)2.

5. The preparation method of the nickel-based material of nitrogen-doped carbon according to claim 2, characterized in that, The solvothermal reaction conditions are: stirring reaction at 20-60°C for 6-12 h.

6. The preparation method of the nickel-based material of nitrogen-doped carbon according to claim 2, wherein, The calcination conditions are: calcining for 0.5-6 h at a temperature of 300-700°C under a nitrogen atmosphere; the reduction baking conditions are: baking for 0.5-6 h at a temperature of 300-600°C under a hydrogen atmosphere.

7. A method for preparing 2,5-furandicarboxamide from 5-hydroxymethylfurfural by using the nickel-based material of nitrogen-doped carbon according to claim 1, characterized in that, It includes the following steps: Add 5-hydroxymethylfurfural, the nickel-based material of the nitrogen-doped carbon and a solvent into a reactor, and react in a hydrogen and ammonia atmosphere to generate 2,5-furandiamine.

8. The method according to claim 7, characterized in that, The mass ratio of the nickel-based material of the nitrogen-doped carbon to 5-hydroxymethylfurfural is 1:2-10.

9. The method according to claim 7, characterized in that, The hydrogen pressure is 1-4 MPa, the ammonia pressure is 0.1-0.5 MPa, the reaction temperature is 120-160°C, and the reaction time is 3-18 h.

10. The method according to claim 7, wherein The solvent is one or more of tetrahydrofuran, 1,4-dioxane, ethanol, methanol, and isopropanol.

Images