Preparation method of carbon-coated nickel-based catalyst and application thereof in selective hydrogenation of 5-hydroxymethylfurfural

Abstract

The present invention relates to the technical fields of catalyst preparation methods and 5-hydroxymethylfurfural catalysis, and particularly relates to a preparation method of a carbon-coated nickel-based catalyst and an application for catalytically preparing 2,5-dihydroxymethylfuran and 2,5-dihydroxymethyltetrahydrofuran from 5-hydroxymethylfurfural at low temperature. By using glucose, nickel nitrate hexahydrate, and isopropanol as raw materials in a one-pot solvothermal method to prepare a nickel-based catalyst coated with a carbon material, and by regulating the reaction conditions (solvent, reaction temperature, hydrogen pressure, reaction time), the catalyst can be used to catalytically prepare compounds such as 2,5-dihydroxymethylfuran and 2,5-dihydroxymethyltetrahydrofuran from 5-hydroxymethylfurfural under mild conditions. The catalyst preparation method in the present invention is relatively simple and has good catalytic effects in the hydrogenation of 5-hydroxymethylfurfural. The catalyst has good stability, strong magnetism, is convenient for separation and recovery, and has excellent industrial application prospects.

Description

Technical Field

[0001] The present invention relates to the technical fields of catalyst preparation and 5-hydroxymethylfurfural catalysis, and particularly relates to a preparation method of a carbon-coated nickel-based catalyst and an application for catalytically preparing 2,5-bis(hydroxymethyl)furan and 2,5-bis(hydroxymethyl)tetrahydrofuran from 5-hydroxymethylfurfural at low temperature Background Art

[0002] With the increasing global attention to issues such as energy, environment, and resources, sustainable development has become an important topic in various fields. Due to the non-renewable nature of fossil resources and the problem of resource depletion, using catalytic conversion of renewable biomass resources to prepare alternatives to fossil resources can be one of the important ways to solve these problems. Therefore, the research on renewable biomass resources has become increasingly important. As a platform compound molecule of biomass resources, 5-hydroxymethylfurfural (HMF) has multiple functional groups and can not only be used as a chemical raw material but also be used to produce various high-value-added chemicals such as fuels, polymers, and solvents. It is considered a bridge connecting biomass resources and alternative fossil resources [Hou, Qidong, et al. Biorefinery roadmap based on catalytic production and upgrading 5-hydroxymethylfurfural[J]. Green Chemistry, 2021, 23(1): 119-231.]. 2,5-Bis(hydroxymethyl)furan (BHMF) and 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF) are important hydrogenation products of 5-hydroxymethylfurfural and have broad application prospects. BHMF can be used as a precursor for various chemicals such as polyesters, polyethers, and fungicides; BHMTHF can be used as a wetting agent, dispersant, decolorizing agent, etc. In 2012, Balakrishnan et al. [Balakrishnan M, Sacia E R, Bell A T. Etherification and reductive etherification of 5-(hydroxymethyl)furfural: 5-(alkoxymethyl)furfurals and 2,5-bis(alkoxymethyl)furans as potential bio-diesel candidates[J]. Green Chemistry, 2012, 14(6): 1626-1634.] reported the use of platinum as a catalyst for the hydrogenation of HMF to prepare BHMF, but the high cost of this method and the scarcity of platinum metal limit its application in the industry.Subsequently, researchers began to search for catalysts to replace platinum, such as noble metals like palladium, rhodium, and ruthenium. These catalysts have high catalytic activity and selectivity, but they also suffer from high costs and scarce raw materials [Chen J, Lu F, Zhang J, et al. Immobilized Ru clusters in nanosized mesoporous zirconium silica for the aqueous hydrogenation of furan derivatives at room temperature [J]. ChemCatChem, 2013, 5(10): 2822-2826.]. Therefore, researchers started to explore the application of non-noble metal catalysts in the hydrogenation of HMF to prepare BHMF. Some non-noble metal catalysts, such as metals like cobalt, copper, and nickel, were found to have certain catalytic activity and selectivity and became the focus of research. Among all non-noble metals, Ni-based catalysts have high hydrogenation activity and are one of the most promising non-noble metals to replace noble metal catalysts. However, their stability in the hydrogenation of HMF is poor, and the reaction process is difficult to control, easily leading to over-hydrogenation of the products. How to design an efficient and stable Ni-based catalyst for the hydrogenation conversion of HMF and controllably prepare BHMF or BHMTHF is a problem that needs to be solved currently. The traditional strategy is to modify the nickel-based catalyst by adding other metals, but this inevitably leads to a decrease in catalyst activity and makes the reaction conditions more demanding. Pomeroy et al. [Pomeroy B, et.al. Process condition-based tuneable selective catalysis of hydroxymethylfurfural (HMF) hydrogenation reactions to aromatic, saturated cyclic and linear poly-functional alcohols over Ni–Ce / Al2O3 [J]. Green Chemistry, 2021, 23(20): 7996-8002.], using Ni–Ce / Al2O3 as the catalyst, obtained 96% of BHMF at 140 °C and 50 bar H2 in a mixed system of water and THF by adjusting the reaction temperature.However, Perret et al. [Perret, Noémie, et al. Catalytic Response and Stability of Nickel / Alumina for the Hydrogenation of 5-Hydroxymethylfurfural in Water [J]. ChemSusChem, 2016, 9(5): 521-531.] prepared a Ni / Al2O3 catalyst with excellent activity by calcining and reducing NiAl layered double hydroxides. At 80 °C and 2 MPa H2, BHMTHF with a 100% yield can be obtained. However, how to further improve the catalytic activity of Ni-based catalysts, design a highly efficient, highly selective and low-cost Ni-based catalyst, and select appropriate reaction conditions to achieve the efficient preparation of BHMF and BHMTHF are important research directions at present. Summary of the Invention

[0003] To solve the problems existing in the above-mentioned prior art, the present invention provides a preparation method of a carbon-coated nickel-based catalyst and its application in the preparation of 2,5-dihydroxymethylfuran and 2,5-dihydroxymethyltetrahydrofuran from 5-hydroxymethylfurfural. This catalyst is a non-precious metal nickel-based catalyst. Using biomass raw material glucose as the carbon source and nickel nitrate as the active metal raw material, a nickel-based catalyst precursor is prepared by a one-pot solvothermal method, and then calcined and reduced to obtain a carbon-coated nickel-based catalyst. The preparation method of this catalyst is simple, and it has a good catalytic effect in the hydrogenation of 5-hydroxymethylfurfural, and can selectively synthesize 2,5-dihydroxymethylfuran and 2,5-dihydroxymethyltetrahydrofuran under low-temperature conditions. Moreover, the catalyst has good stability, strong magnetism, is convenient for separation and recovery, and has excellent industrial application prospects.

[0004] To achieve the above object, the present invention provides a carbon-coated nickel-based catalyst, which is prepared by the following method:

[0005] (1) Weigh a certain mass of glucose and nickel nitrate hexahydrate and dissolve them in an isopropanol solution. Heat the mixed solution to 40-70 °C to assist the dissolution of glucose and nickel nitrate, and then transfer it to a closed high-pressure resistant reaction kettle. Heat it to 150-200 °C under magnetic stirring and keep it for 4-8 h. After cooling to room temperature, filter it under reduced pressure, wash the filter cake, and dry it in vacuum at 60-100 °C to obtain a solid named Ni-GL.

[0006] The addition ratio of the glucose, nickel nitrate hexahydrate and isopropanol is (0.5-3) g: (0.5-3) g: (50-300) mL.

[0007] (2) The catalyst precursor (Ni-GL) obtained in step (1) is subjected to temperature-programmed reduction in a nitrogen atmosphere, and after cooling to room temperature, it is passivated with oxygen to obtain a carbon-coated nickel-based catalyst (Ni@C-T, where T represents the reduction temperature: 250, 300, 400, 500, 600, 700).

[0008] It is characterized in that the addition amounts of glucose, nickel nitrate hexahydrate, and isopropyl alcohol are in the ratio of (1 - 2) g : (1 - 2) g : (100 - 250) mL.

[0009] Further, the auxiliary dissolution temperature in step (1) is 60 °C.

[0010] Further, the reaction temperature in the reaction kettle in step (1) is 180 °C, and it is maintained for 6 h.

[0011] Further, the filtration and washing process in step (1) is to wash three times with anhydrous ethanol and three times with ultrapure water.

[0012] Further, the vacuum drying temperature in step (1) is 80 °C.

[0013] Further, the reduction process in step (2) is as follows: In a nitrogen-purged tubular furnace, it is heated to 200 - 700 °C at a rate of 2 °C / min, held for 1 - 3 h, and then naturally cooled to room temperature.

[0014] Preferably: In a nitrogen-purged tubular furnace, it is heated to 300 °C at a rate of 2 °C / min, held for 2 h, and then naturally cooled to room temperature.

[0015] Further, the oxygen passivation process in step (2) is to passivate with a mixed gas of oxygen and nitrogen with an oxygen volume percentage of 1% for 2 h.

[0016] The present invention also provides an application of the above carbon-coated nickel-based (Ni@C-T) catalyst in the hydrogenation of 5-hydroxymethylfurfural to prepare 2,5-bis(hydroxymethyl)furan and 2,5-bis(hydroxymethyl)tetrahydrofuran.

[0017] The catalyst, solvent, and 5-hydroxymethylfurfural are added to a high-pressure-resistant reaction kettle according to the dosage ratio of (10 - 50) mg : (10 - 20) mL : 1 mmol. After sealing the reaction kettle, it is filled with 1 bar - 50 bar of hydrogen, and reacted under magnetic stirring at 25 - 120 °C for 0.5 - 3 h to obtain 2,5-bis(hydroxymethyl)furan and 2,5-bis(hydroxymethyl)tetrahydrofuran.

[0018] Preferably, the catalyst, methanol and 5-hydroxymethylfurfural are added to a high-pressure resistant reactor in a dosage ratio of 40 mg: 10 mL: 1 mmol. After sealing the reactor, 10 bar of hydrogen is charged, and the reaction is carried out under magnetic stirring at 50 °C for 2 h to obtain 2,5-bis(hydroxymethyl)furan.

[0019] Preferably, the catalyst, water and 5-hydroxymethylfurfural are added to a high-pressure resistant reactor in a dosage ratio of 40 mg: 10 mL: 1 mmol. After sealing the reactor, 10 bar of hydrogen is charged, and the reaction is carried out under magnetic stirring at 40 °C for 1.5 h to obtain 2,5-bis(hydroxymethyl)tetrahydrofuran.

[0020] Compared with the prior art, the present invention has the following advantages and effects:

[0021] In the present invention, the preparation method of the nickel-based catalyst is relatively simple. Using biomass derivative glucose as the carbon source and non-noble metal nickel as the active metal, the catalyst precursor is prepared by a one-pot solvothermal method. Due to the coordination of nickel and glucose, the high dispersion of nickel metal is achieved, which hinders the aggregation of nickel at high temperatures to a certain extent. At the same time, after calcination and reduction, the carbon layer coats the nickel metal, alleviating the problem that nickel is easily oxidized and deactivated during the reaction.

[0022] The catalyst prepared above in the present invention is used for the hydrogenation of 5-hydroxymethylfurfural to prepare 2,5-bis(hydroxymethyl)furan and 2,5-bis(hydroxymethyl)tetrahydrofuran, which has obvious advantages: compared with the existing noble metal catalytic system, the cost is lower; compared with the non-noble metal catalyst system, the reaction conditions are milder.

[0023] To further illustrate the effects of the present invention, the following table shows the comparison of the effects of the method of the present invention and the prior art.

[0024]

[0025] The references described therein are respectively:

[0026] 1. R J, Oliva H, Belmar J, et al. Selective hydrodeoxygenation of biomass derived 5-hydroxymethylfurfural over silica supported iridium catalysts[J]. Applied Catalysis B: Environmental, 2019, 241: 270-283.

[0027] 2. Chen Q, Li T, Zhou Y, et al. Selective hydrogenation of 5-hydroxymethylfurfural via zeolite encapsulation to avoid further hydrodehydroxylation[J]. Industrial & Engineering Chemistry Research, 2020, 59(26): 12004-12012

[0028] 3. Chatterjee M, Ishizaka T, Kawanami H. Selective hydrogenation of 5-hydroxymethylfurfural to 2,5-bis-(hydroxymethyl)furan using Pt / MCM-41 in an aqueous medium: a simple approach[J]. Green Chemistry, 2014, 16(11): 4734-4739.

[0029] 4. Wiesfeld J J, Kim M, Nakajima K, et al. Selective hydrogenation of 5-hydroxymethylfurfural and its acetal with 1,3-propanediol to 2,5-bis(hydroxymethyl)furan using supported rhenium-promoted nickel catalysts in water[J]. Green chemistry, 2020, 22(4): 1229-1238

[0030] 5. Feng Y, Yan G, Wang T, et al. Cu 1–Cu 0 bicomponent CuNPs@ZIF-8 for highly selective hydrogenation of biomass derived 5-hydroxymethylfurfural[J]. Green Chemistry, 2019, 21(16): 4319-4323.

[0031] 6. Pomeroy B, Grilc M, Likozar B. Process condition-based tunable selective catalysis of hydroxymethylfurfural (HMF) hydrogenation reactions to aromatic, saturated cyclic and linear poly-functional alcohols over Ni–Ce / Al2O3[J]. Green Chemistry, 2021, 23(20): 7996-8002.

[0032] 7. Perret N, Grigoropoulos A, Zanella M, et al. Catalytic Response and Stability of Nickel / Alumina for the Hydrogenation of 5-Hydroxymethylfurfural in Water[J]. ChemSusChem, 2016, 9(5): 521-531.

[0033] 8. Zhang S, Ma H, Sun Y, et al. Catalytic selective hydrogenation and rearrangement of 5-hydroxymethylfurfural to 3-hydroxymethyl-cyclopentone over a bimetallic nickel–copper catalyst in water[J]. Green Chemistry, 2019, 21(7): 1702-1709. Brief Description of the Drawings

[0034] Figure 1 It is a simple flow chart of the preparation method of the catalyst with the best effect for the present invention.

[0035] Figure 2 It is the X-ray diffraction pattern (XRD pattern) of the carbon-coated nickel-based catalyst precursor (Ni-GL), glucose, and nickel nitrate hexahydrate prepared in Example 1.

[0036] Figure 3 It is the Fourier transform infrared spectroscopy (FT-IR) diagram of the carbon-coated nickel-based catalyst precursor (Ni-GL), glucose, and nickel nitrate hexahydrate prepared in Example 1.

[0037] Figure 4 Scanning electron microscope image of the carbon-coated nickel-based catalyst precursor (Ni-GL) prepared in Example 1.

[0038] Figure 5 Particle size distribution diagram of the carbon-coated nickel-based catalyst precursor (Ni-GL) prepared in Example 1.

[0039] Figure 6 EDS energy spectrum diagram of the carbon-coated nickel-based catalyst precursor (Ni-GL) prepared in Example 1.

[0040] Figure 7 Thermogravimetric curve of the carbon-coated nickel-based catalyst precursor (Ni-GL) prepared in Example 1.

[0041] Figure 8 X-ray diffraction pattern (XRD pattern) of the carbon-coated nickel-based catalyst (Ni@C-T, where T represents the reduction temperature: 250, 300, 400, 500, 600, 700) prepared in Example 1.

[0042] Figure 9 Transmission electron microscope image (TEM image) of the carbon-coated nickel-based catalysts (Ni@C-300, Ni@C-700) prepared in Example 1.

[0043] Figure 10 Ni2p spectrum of the X-ray photoelectron spectroscopy (XPS spectrum) of the carbon-coated nickel-based catalysts (Ni@C-250, Ni@C-300, Ni@C-400) prepared in Example 1.

[0044] Figure 11 Raman spectrum (Raman pattern) of the carbon-coated nickel-based catalysts (Ni@C-T, where T represents the reduction temperature: 250, 300, 400, 500, 600, 700) prepared in Example 1. Detailed implementation mode

[0045] The technical solutions of the present invention will be described in detail below in conjunction with specific embodiments and the accompanying drawings of the specification, but the following embodiments are not used to limit the scope of protection required by the present invention.

[0046] Unless otherwise specified, the reagents and instruments used in the following examples are all commercially available products. The specific implementation cases are as follows:

[0047] Example 1. A carbon-coated nickel-based catalyst (Ni@C-T) is prepared by the following method:

[0048] As Figure 1Brief flow chart of the preparation method of the catalyst of the present invention. First, weigh 1.8 g of glucose, 1.3 g of nickel nitrate hexahydrate, and 200 ml of isopropanol into a 250 ml pressure-resistant stainless steel reactor. Seal the reactor, stir at 60 °C for 1 h, then heat up to 180 °C and hold for 6 h. After cooling to room temperature, filter, wash three times with anhydrous ethanol and ultrapure water respectively, and dry at 80 °C under vacuum for 12 h to obtain a solid named Ni-GL.

[0049] (2) Heat the catalyst precursor (Ni-GL) obtained in step (1) to 300 °C at a rate of 2 °C / min in a nitrogen-purged tubular furnace, hold for 2 h, and cool naturally to room temperature. Subsequently, passivate it with a mixture of oxygen and nitrogen with an oxygen volume percentage of 1% for 2 h to obtain the Ni@C-300 catalyst. According to the same method, only changing the calcination reduction temperature, a series of carbon-coated nickel-based catalysts (Ni@C-T, T represents the reduction temperature: 250, 300, 400, 500, 600, 700) are obtained.

[0050] Perform X-ray diffraction (XRD) analysis on the catalyst precursor (Ni-GL) prepared in Example 1, as Figure 2 shown, the characteristic diffraction peaks of glucose and nickel nitrate have completely disappeared, and glucose has undergone aromatization or carbonization at high temperature and lost its original structure [Angew. Chem. Int. Ed., 2004, 43]. At the same time, it can be found that two relatively weak new diffraction peaks appear at 2θ = 21.2° and 35.8°, which may be diffraction peaks related to divalent nickel.

[0051] Figure 3 is the Fourier transform infrared spectroscopy (FT-IR) diagram of the catalyst precursor (Ni-GL) prepared in Example 1, glucose, and nickel nitrate hexahydrate. The wavelength range of 3200 - 3650 cm -1 is the stretching vibration peak of -OH. Compared with glucose and Ni-GL, the peak of -OH shows an obvious blue shift phenomenon, which can be attributed to the increase of intermolecular hydrogen bonds in Ni-GL or the interaction between nickel and hydroxyl groups, resulting in a change in the charge distribution of -OH, thus causing the blue shift phenomenon. Dehydration and aromatization are usually considered processes that reduce the number of functional groups. The peak centered at 1628 cm -1 can be attributed to the C=C vibration, indicating that glucose has undergone aromatization at high temperature. The spectral band in the range of v = 1000 - 1300 cm -1 includes C-OH stretching and -OH bending vibrations, indicating the presence of a large number of residual hydroxyl groups.

[0052] Scan the catalyst precursor (Ni-GL) prepared in Example 1 with a scanning electron microscope (SEM). The obtained scanning electron microscope spectrum and the measured particle size distribution diagram of the precursor are as Figure 4 、5 As shown, it can be found from the figure that the catalyst precursor prepared by the solvothermal method has a uniform structure and uniform size, and is a regular spherical carbon sphere with an average size of 886.5 nm. Through Figure 6 the SEM-EDS spectrum, it can be seen that Ni is uniformly distributed in the precursor.

[0053] Figure 7 is the thermal decomposition diagram of Ni-GL. The weight loss of Ni-GL can be divided into three stages. The first stage is 30-200 °C, and this stage can be attributed to the weight loss of adsorbed water. The catalyst structure has not changed, and subsequent XPS characterization also shows that at 200 °C, Ni is not reduced. The second stage can be divided into 200-350 °C. Among them, at 283 °C, the material has a relatively fast weight loss in this stage, which can reach -2.03% / min. The third stage is 350-450 °C, and the fastest weight loss rate is -6.23% / min. In this stage, the carbon material is mainly decomposed into small molecule substances such as furans, ketones, aldehydes and phenols.

[0054] Figure 8 is the X-ray diffraction pattern (XRD pattern) of the carbon-coated nickel-based catalyst (Ni@C-T). When the catalyst precursor (Ni-GL) is calcined and reduced at 250 °C, there are no newly appeared nickel-related diffraction peaks in the diffraction pattern of the obtained Ni@C-250 catalyst. As the calcination temperature increases, the relevant diffraction peaks of metallic Ni 0 appear. By comparing with the PDF card database, the diffraction pattern of the catalyst can be well matched with the PDF card of nickel (JCPDS, PDF#65-2865). The characteristic peaks 2θ = 44.5°, 51.9°, and 76.4° correspond to the (111), (200), and (220) crystal planes of Ni 0 respectively. As the calcination temperature increases, the relevant diffraction peak intensity is stronger and the full width at half maximum is narrower, indicating that the crystallinity of Ni is higher. Calculated by the Scherrer formula, the size of nickel nanoparticles in the catalyst is 5.10 nm when calcined at 300 °C, and the size of nickel nanoparticles increases to 35.89 nm when calcined at 700 °C.

[0055] The carbon-coated nickel-based catalyst was observed by transmission electron microscopy (TEM), and the obtained transmission electron microscopy images are as shown in Figure 9 (Ni@C-300: a-c; Ni@C-700: d-f.). It can be clearly seen in the TEM images that nickel nanoparticles are uniformly embedded in the carbon material and are uniformly distributed without obvious agglomeration. At the same time, as the calcination temperature increases, the size of nickel nanoparticles in the catalyst increases, which is consistent with the XRD data. The uniform dispersion of nickel can be attributed to the interaction between nickel and glucose in the catalyst precursor, indicating that a highly dispersed carbon-coated Ni-based catalyst can be prepared by this method.

[0056] Figure 10 The Ni2p diagram of the carbon-coated nickel-based catalyst (Ni@C-250, Ni@C-300, Ni@C-400) prepared earlier in this example is obtained from the X-ray photoelectron spectroscopy (XPS). The Ni2p diagram of the Ni@C-250 catalyst reduced at 250°C has no Ni2p binding energy. 0 The related peaks indicate that at this temperature, Ni 2+ Cannot be reduced. As the calcination reduction temperature increases, nickel is reduced more thoroughly. 0 Higher content.

[0057] The carbon-coated nickel-based catalyst (Ni@CT) prepared in the previous example was subjected to Raman spectroscopy analysis, and the obtained Raman spectrum was as follows: Figure 11 As shown in the figure, it can be seen that there are two obvious peaks in the Ni@C catalyst, the peak at 1380 cm -1 and 1590cm -1 This is attributed to the in-plane vibration of graphitized carbon and disordered amorphous carbon, called D band and G band, respectively. The intensity ratio of D band and G band of Ni-GL (I D / I G ) is 0.71, indicating that the ordered structure of carbon in Ni-GL is high. As the calcination temperature increases, I D / I G The ratio of first increases and then decreases, indicating that the defects of carbon materials first increase and then decrease. D / I G The decrease in the ratio may be due to the increase in graphitized carbon in the material, which leads to a more regular material structure.

[0058] Example 2

[0059] Ni@C-250 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and methanol (10 mL) were added to an autoclave. After sealing the autoclave, the air in the autoclave was replaced with hydrogen 5-6 times, followed by a 20-bar charge of hydrogen. The autoclave was then heated to 100°C and stirred at 1000 RPM (rotations per minute, r / min) for 1 hour. After the reaction was complete, the autoclave was cooled to room temperature and depressurized. The reaction mixture was opened and filtered, and the reaction solution was analyzed by gas chromatography (Agilent 7890A) and the product was identified by gas chromatography-mass spectrometry (Trace 1300-ISQ). The calculated HMF conversion was 40%, and the molar yield of 2,5-dihydroxymethylfuran was 5%.

[0060] Example 3

[0061] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and methanol (10 mL) were added to a high-pressure resistant reactor. After sealing the reactor, the air in the reactor was replaced with hydrogen 5 - 6 times, 20 bar of hydrogen was charged, and the mixture was heated to 100 °C at a stirring speed of 1000 rpm for reaction for 1 h. After cooling to room temperature, the reaction solution was detected by gas chromatography (Agilent-7890A), and the product was identified by gas chromatography-mass spectrometry (Trace 1300-ISQ). The conversion rate of HMF was calculated to be 98%, and the molar yield of 2,5-bis(hydroxymethyl)furan was 78%.

[0062] Example 4

[0063] The Ni@C-400 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and methanol (10 mL) were added to a high-pressure resistant reactor. After sealing the reactor, the air in the reactor was replaced with hydrogen 5 - 6 times, 20 bar of hydrogen was charged, and the mixture was heated to 100 °C at a stirring speed of 1000 rpm for reaction for 1 h. After cooling to room temperature, the reaction solution was detected by gas chromatography (Agilent-7890A), and the product was identified by gas chromatography-mass spectrometry (Trace 1300-ISQ). The conversion rate of HMF was calculated to be 73%, and the molar yield of 2,5-bis(hydroxymethyl)furan was 46%.

[0064] Example 5

[0065] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and methanol (10 mL) were added to a high-pressure resistant reactor. After sealing the reactor, the air in the reactor was replaced with hydrogen 5 - 6 times, 20 bar of hydrogen was charged, and the mixture was heated to 50 °C at a stirring speed of 1000 rpm for reaction for 1 h. After cooling to room temperature, the reaction solution was detected by gas chromatography (Agilent-7890A), and the product was identified by gas chromatography-mass spectrometry (Trace 1300-ISQ). The conversion rate of HMF was calculated to be 79%, and the molar yield of 2,5-bis(hydroxymethyl)furan was 75%.

[0066] Example 6

[0067] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and methanol (10 mL) were added to a high-pressure resistant reactor. After sealing the reactor, the air in the reactor was replaced with hydrogen 5 - 6 times, 20 bar of hydrogen was charged, and the mixture was heated to 30 °C at a stirring speed of 1000 rpm for reaction for 1 h. After cooling to room temperature, the reaction solution was detected by gas chromatography (Agilent-7890A), and the products were identified using a gas chromatography-mass spectrometry instrument (Trace 1300-ISQ). The conversion rate of HMF was calculated to be 27%, and the molar yield of 2,5-bis(hydroxymethyl)furan was 27%.

[0068] Example 7

[0069] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and methanol (10 mL) were added to a high-pressure resistant reactor. After sealing the reactor, the air in the reactor was replaced with hydrogen 5 - 6 times, 10 bar of hydrogen was charged, and the mixture was heated to 50 °C at a stirring speed of 1000 rpm for reaction for 1 h. After cooling to room temperature, the reaction solution was detected by gas chromatography (Agilent-7890A), and the products were identified using a gas chromatography-mass spectrometry instrument (Trace 1300-ISQ). The conversion rate of HMF was calculated to be 77%, and the molar yield of 2,5-bis(hydroxymethyl)furan was 73%.

[0070] Example 8

[0071] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and methanol (10 mL) were added to a high-pressure resistant reactor. After sealing the reactor, the air in the reactor was replaced with hydrogen 5 - 6 times, 10 bar of hydrogen was charged, and the mixture was heated to 50 °C at a stirring speed of 1000 rpm for reaction for 10 min. After cooling to room temperature, the reaction solution was detected by gas chromatography (Agilent-7890A), and the products were identified using a gas chromatography-mass spectrometry instrument (Trace 1300-ISQ). The conversion rate of HMF was calculated to be 45%, and the molar yield of 2,5-bis(hydroxymethyl)furan was 45%.

[0072] Example 9

[0073] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and methanol (10 mL) were added to a high-pressure resistant reactor. After sealing the reactor, the air in the reactor was replaced with hydrogen 5 - 6 times, 10 bar of hydrogen was charged, and the mixture was heated to 50 °C at a stirring speed of 1000 rpm for 0.5 h. After cooling to room temperature, the reaction solution was detected by gas chromatography (Agilent-7890A), and the product was identified using a gas chromatography-mass spectrometry instrument (Trace 1300-ISQ). The HMF conversion was calculated to be 58%, and the molar yield of 2,5-bis(hydroxymethyl)furan was 57%.

[0074] Example 10

[0075] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and methanol (10 mL) were added to a high-pressure resistant reactor. After sealing the reactor, the air in the reactor was replaced with hydrogen 5 - 6 times, 10 bar of hydrogen was charged, and the mixture was heated to 50 °C at a stirring speed of 1000 rpm for 1.5 h. After cooling to room temperature, the reaction solution was detected by gas chromatography (Agilent-7890A), and the product was identified using a gas chromatography-mass spectrometry instrument (Trace 1300-ISQ). The HMF conversion was calculated to be 89%, and the molar yield of 2,5-bis(hydroxymethyl)furan was 81%.

[0076] Example 11

[0077] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and methanol (10 mL) were added to a high-pressure resistant reactor. After sealing the reactor, the air in the reactor was replaced with hydrogen 5 - 6 times, 10 bar of hydrogen was charged, and the mixture was heated to 50 °C at a stirring speed of 1000 rpm for 2 h. After cooling to room temperature, the reaction solution was detected by gas chromatography (Agilent-7890A), and the product was identified using a gas chromatography-mass spectrometry instrument (Trace 1300-ISQ). The HMF conversion was calculated to be 96%, and the molar yield of 2,5-bis(hydroxymethyl)furan was 90%.

[0078] Example 12

[0079] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and water (10 mL) were added to a high-pressure resistant reaction kettle. After sealing the reaction kettle, the air in the reaction kettle was replaced with hydrogen 5 - 6 times, 20 bar of hydrogen was charged, and the mixture was heated to 100 °C at a stirring speed of 1000 rpm for reaction for 1 h. After cooling to room temperature, the reaction solution was detected by liquid chromatography (Agilent-1260Infinity II). The conversion rate of HMF was calculated to be 100%, and the molar yield of 2,5-bis(hydroxymethyl)tetrahydrofuran was 92%.

[0080] Example 13

[0081] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and water (10 mL) were added to a high-pressure resistant reaction kettle. After sealing the reaction kettle, the air in the reaction kettle was replaced with hydrogen 5 - 6 times, 10 bar of hydrogen was charged, and the mixture was heated to 60 °C at a stirring speed of 1000 rpm for reaction for 1 h. After cooling to room temperature, the reaction solution was detected by liquid chromatography (Agilent-1260Infinity II). The conversion rate of HMF was calculated to be 100%, and the molar yield of 2,5-bis(hydroxymethyl)tetrahydrofuran was 93%.

[0082] Example 14

[0083] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and water (10 mL) were added to a high-pressure resistant reaction kettle. After sealing the reaction kettle, the air in the reaction kettle was replaced with hydrogen 5 - 6 times, 10 bar of hydrogen was charged, and the mixture was heated to 30 °C at a stirring speed of 1000 rpm for reaction for 1 h. After cooling to room temperature, the reaction solution was detected by liquid chromatography (Agilent-1260Infinity II). The conversion rate of HMF was calculated to be 100%, the molar yield of 2,5-bis(hydroxymethyl)furan was 45%, and the molar yield of 2,5-bis(hydroxymethyl)tetrahydrofuran was 48%.

[0084] Example 15

[0085] The Ni@C-300 catalyst (40 mg), 5-hydroxymethylfurfural (1 mmol), and water (10 mL) were added to a high-pressure resistant reaction kettle. After sealing the reaction kettle, the air in the reaction kettle was replaced with hydrogen 5 - 6 times, 10 bar of hydrogen was charged, and the mixture was heated to 40 °C at a stirring speed of 1000 rpm for reaction for 1.5 h. After cooling to room temperature, the reaction solution was detected by liquid chromatography (Agilent-1260Infinity II). The conversion rate of HMF was calculated to be 100%, and the molar yield of 2,5-bis(hydroxymethyl)tetrahydrofuran was 91%.

[0086] By screening different catalysts, it was found that nickel in the Ni@C-300 catalyst was well-dispersed with small particle sizes, and the carbon support had a high degree of defects, making the Ni@C-300 catalyst have the best activity in HMF hydrogenation. At the same time, by adjusting the reaction conditions (solvent, reaction temperature, hydrogen pressure, reaction time), the selective preparation of BHMF in methanol solvent and the complete hydrogenation to prepare BHMTHF in water solvent were realized.

[0087] The above are only the preferred embodiments of the present invention, and thus the scope of implementation of the present invention cannot be limited thereby. Equivalent changes and modifications made according to the scope of the present invention patent and the content of the specification should be regarded as part of the scope covered by the present invention.

Claims

1. Application of a carbon-coated nickel-based catalyst in the hydrogenation of 5-hydroxylfurfural to prepare 2,5-bis(hydroxymethyl)furan and 2,5-bis(hydroxymethyl)tetrahydrofuran, characterized in that: The preparation method of the catalyst is as follows: (1) Weigh glucose and nickel nitrate hexahydrate and dissolve them in an isopropanol solution. Heat the mixed solution to 40 - 70 °C for dissolution, then transfer it to a sealable high-pressure reaction kettle. Heat it to 150 - 200 °C under magnetic stirring and keep it for 4 - 8 h; after cooling to room temperature, filter it under reduced pressure, wash the filter cake, and dry it at 60 - 100 °C in vacuum to obtain the catalyst precursor Ni-GL; Among them, the dosage ratio of glucose, nickel nitrate hexahydrate, and isopropanol is 0.5 - 3 g: 0.5 - 3 g: 50 - 300 mL; (2) The catalyst precursor obtained in step (1) is reduced under a nitrogen atmosphere with a programmed temperature increase. After cooling to room temperature, it is passivated with O2 oxygen to obtain a carbon-coated nickel-based catalyst Ni@C-T, where T represents the reduction temperature: 250 °C, 300 °C, 400 °C, 500 °C, 600 °C, 700 °C; the reduction process is as follows: in a nitrogen-purged tube furnace, heat it to 200 - 700 °C at a rate of 1 - 3 °C / min and keep it for 1 - 3 h; the oxygen passivation process is to passivate it with a mixed gas of oxygen and nitrogen with an oxygen volume percentage of 0.5 - 1.5% for 1 - 3 h; The application method of the catalyst includes the following steps: Add the catalyst Ni@C-T, solvent, and 5-hydroxymethylfurfural into a high-pressure reaction kettle according to the dosage ratio of 30 - 40 mg: 10 - 15 mL: 1 mmol. After sealing the reaction kettle, fill it with 10 bar - 20 bar of hydrogen, and react at 800 - 1500 rpm under magnetic stirring at 50 - 100 °C for 1.5 - 2 h to obtain 2,5-bis(hydroxymethyl)furan and 2,5-bis(hydroxymethyl)tetrahydrofuran.

2. The application according to claim 1, characterized in that: The dosage ratio of glucose, nickel nitrate hexahydrate, and isopropanol is 1 - 2 g: 1 - 2 g: 100 - 250 mL.

3. The application according to claim 1, wherein: In step (2), the heating rate in the reduction process is 2 °C / min and the holding time is 2 h.

4. The application according to claim 1, wherein: In step (2), the oxygen passivation process is to passivate it with a mixed gas of oxygen and nitrogen with an oxygen volume percentage of 1% for 2 h.

5. The application according to claim 1, characterized in that: The solvent is one of water and methanol.

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