A nickel-based transition metal carbide catalyst, a preparation method and application thereof

Abstract

The application discloses a nickel-based transition metal carbide catalyst and a preparation method and application thereof, and belongs to the technical field of preparation of supported catalysts and the field of biomass-based catalytic application. The nickel-based transition metal carbide catalyst containing Lewis acid sites and electron-rich metal sites is obtained based on a liquid-solid-solid process, carburizing treatment and a wet reduction strategy, has catalytic activity comparable to that of a homogeneous liquid acid catalyst, is convenient to recycle and has excellent stability, can be well applied to hydrogenation reaction of 5-HMF, can selectively regulate generation of various high-value hydrogenation products, can realize high-value utilization of bio-based oxygen-containing chemicals, and has extremely high economic benefits.

Description

Technical Field

[0001] This invention relates to supported catalyst preparation technology and biomass-based catalytic applications, specifically to a nickel-based transition metal carbide catalyst, its preparation method, and its applications. Background Technology

[0002] Renewable and abundant lignocellulosic biomass can be converted into high-value-added fuels and chemicals, among which 5-hydroxymethylfurfural (5-HMF) has enormous market potential and is considered a "sleeping giant" in the field of sustainable chemistry. The outstanding advantage of 5-HMF lies in its possession of multiple oxygen-containing functional groups, including carbonyl, hydroxymethyl, and furan rings, retaining sufficient reactivity. Therefore, selectively hydrogenating 5-HMF is quite difficult. When the active component acts on the aldehyde group for hydrogenation and reduction to hydroxymethyl, 2,5-furandiethanol (BHMF) is obtained. It is a high-value-added diol with a special chemical structure. It is an important polymer monomer and pharmaceutical synthesis intermediate, and can be used to synthesize polymer materials such as polyesters and polyurethanes. It has the same aromaticity as the petroleum-based chemical terephthalic acid, so BHMF has great potential to replace terephthalic acid in the synthesis of polymer materials. When the active component acts on the hydroxymethyl group for reduction, 5-methylfurfural (MF) can be obtained, which is an important food additive and synthesis intermediate. When the active component continues to act on the aldehyde group and hydroxymethyl group (avoiding excessive hydrogenation of the furan ring), 5-methyl-2-furanethanol (MFA) and 2,5-dimethylfuran (DMF) can be obtained successively. DMF has high energy density (30 MJ / L) and high octane number (119). It is soluble in gasoline and is a second-generation liquid biofuel. It has advantages such as easy transportation and management, high combustion efficiency, non-hygroscopicity, and low energy consumption for separation and purification. It is the most widely studied fuel substitute. Therefore, selective hydrogenation of 5-HMF is key to converting it into high-value-added biomass-based oxygenated chemicals and liquid fuels.

[0003] Currently, the hydrogenation reduction of 5-HMF primarily utilizes high-performance noble metal catalysts, mainly including ruthenium (Ru), platinum (Pt), and palladium (Pd). For example, Pt / MCM-41 and Ru / MnCo2O4 exhibit high selectivity for BHMF, while Pd / MOF-808 shows high selectivity for DMF. However, the high cost and scarcity of noble metal catalysts limit their large-scale industrial application. Therefore, the use of inexpensive, readily available, and hydrogenation-advantageous non-noble metal nickel (Ni) as a substitute is being considered. Based on existing research, the catalyst support structure has a significant impact on catalytic performance. Commonly used catalyst supports include metal oxides, molecular sieves, and carbon materials. Among these, carbon materials, with their excellent porosity, structural diversity, and superior stability, can effectively attach active components to the support surface or pores. Transition metal carbides are a particularly attractive type of carbon material, being intermetallic filled compounds. Tungsten carbide, in particular, has surface electronic properties similar to Pt and exhibits good catalytic activity in hydrogenation reactions. Therefore, nickel-based transition metal carbides with dual hydrogenation properties offer new possibilities for the selective hydrogenation of 5-HMF. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention proposes a nickel-based transition metal carbide catalyst, its preparation method, and its application. This catalyst is highly efficient and stable, enabling selective hydrogenation of 5-HMF to obtain biomass-based high-value-added chemicals.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a nickel-based transition metal carbide catalyst is as follows: First, dopamine hydrochloride and a metal complex salt are dissolved in deionized water to form a metal-dopamine hydrochloride complex. Then, ethanol and ammonia are added to the complex and stirred. The precipitate is collected to obtain a metal-dopamine hydrochloride precursor. Next, the metal-dopamine hydrochloride precursor is carburized to obtain a transition metal carbide. Then, the transition metal carbide is added to a nickel compound solution and ultrasonically treated. Finally, sodium borohydride solution is added under a low-temperature nitrogen atmosphere. After standing at room temperature, the solution is filtered, washed, and dried to obtain the nickel-based transition metal carbide.

[0007] Furthermore, the metal complex salt is one of ammonium metatungstate, ammonium metavanadate, and ammonium molybdate.

[0008] Furthermore, the mass ratio of dopamine hydrochloride to the metal complex salt is 1:0.5-2.

[0009] Furthermore, the carburizing treatment is carried out under a nitrogen atmosphere, with the temperature increased to 900-1100℃ at a heating rate of 1-5℃ / min, and held at that temperature for 1-8 hours.

[0010] Furthermore, the compound of metallic nickel is one of nickel nitrate, nickel chloride, and nickel sulfate, with a concentration of 0.15-0.30 mol / L.

[0011] Furthermore, the concentration of the added sodium borohydride solution is 0.30-0.50 mol / L.

[0012] Furthermore, the preparation method of the nickel-based transition metal carbide catalyst includes the following steps:

[0013] (1) Dopamine hydrochloride and metal complex salt in a mass ratio of 1:0.5-2 are dissolved in deionized water and stirred to form metal-dopamine hydrochloride complex. Ethanol is added to the above solution and ammonia is added rapidly while stirring. Stirring is continued at room temperature. The precipitate is collected by centrifugation, filtered, washed and dried to obtain metal-dopamine hydrochloride precursor.

[0014] (2) The metal-dopamine hydrochloride precursor was placed in a tube furnace and heated to 900-1100℃ at a heating rate of 1-5℃ / min under a nitrogen atmosphere, and held for 1-8h to carry out carburizing treatment to obtain transition metal carbides.

[0015] (3) The transition metal carbide was added to any one of nickel nitrate, nickel chloride and nickel sulfate solutions with a concentration of 0.15-0.30 mol / L and mixed thoroughly. The resulting mixture was ultrasonically treated and placed in a low-temperature reactor. A sodium borohydride solution with a concentration of 0.30-0.50 mol / L was slowly added under a continuous nitrogen atmosphere. The mixture was then allowed to stand at room temperature. Finally, it was filtered, washed three times with deionized water and ethanol respectively, and dried in a vacuum drying oven at 60°C for 12 h to obtain nickel-based transition metal carbide.

[0016] Furthermore, the nickel-based transition metal carbide catalyst prepared by the aforementioned method is a nickel-based transition metal carbide catalyst.

[0017] Furthermore, the application of the nickel-based transition metal carbide catalyst in the selective hydrogenation reaction of 5-HMF.

[0018] Furthermore, the application is as follows: 5-HMF, nickel-based transition metal carbide catalyst and reaction solvent are mixed and placed in a sealed high-pressure reactor, the air is replaced with hydrogen and hydrogen is used as hydrogen donor to carry out hydrogenation reaction, the reaction temperature is 160-190℃ and the reaction time is 0.5-3h.

[0019] Compared with existing technologies, the advantages of this invention are:

[0020] 1) This invention obtains a nickel-based transition metal carbide catalyst containing Lewis acid sites and electron-rich metal sites based on liquid-solid-solid process, carburizing treatment and wet reduction strategy. The catalytic activity is comparable to that of homogeneous liquid acid catalysts, which are easy to recycle and have excellent stability.

[0021] 2) The catalyst of the present invention can be well applied to the hydrogenation reaction of 5-HMF, and can also selectively control the generation of a variety of high-value-added hydrogenation products.

[0022] 3) This invention uses non-precious metal nickel (Ni)-based transition metal carbide catalysts with hydrogenation advantages for selective hydrogenation of 5-HMF. While ensuring high selectivity, it reduces operating costs and is conducive to large-scale industrial application.

[0023] 4) The transition metal carbide of this invention is a highly attractive carbon material. It is an intermetallic filling compound in which the surface electronic properties of tungsten carbide are similar to those of Pt, exhibiting good catalytic activity in catalytic hydrogenation reactions. Therefore, nickel-based transition metal carbides with dual-effect hydrogenation performance provide new possibilities for the selective hydrogenation of 5-HMF. Attached Figure Description

[0024] Figure 1 Gas chromatograms of products from the selective hydrogenation of 5-HMF catalyzed by nickel-based transition metal carbide catalysts at different time points;

[0025] Figure 2 This is a pathway diagram for the selective hydrogenation of 5-HMF.

[0026] Figure 3 The tungsten carbide and Ni obtained in Example 4 0.30 NH3-TPD characterization diagram of @WC-1;

[0027] Figure 4 The tungsten carbide and Ni obtained in Example 4 0.30 Py-FTIR characterization of @WC-1;

[0028] Figure 5 The tungsten carbide and Ni obtained in Example 4 0.30 @WC-1's XPS Ni 2p 3 / 2 picture;

[0029] Figure 6 The tungsten carbide and Ni obtained in Example 4 0.30 @WC-1's XPS W 4f screenshot. Detailed Implementation

[0030] To make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to specific examples.

[0031] Example 1

[0032] A method for selective hydrogenation of 5-HMF catalyzed by nickel-based transition metal carbides, comprising the following specific steps:

[0033] (1) Dopamine hydrochloride and ammonium metatungstate in a mass ratio of 1:0.5 were dissolved in deionized water and stirred to form a tungsten-dopamine hydrochloride complex. Ethanol was added to the above solution and ammonia was added rapidly while stirring. The mixture was stirred continuously at room temperature. The precipitate was collected by centrifugation, filtered, washed and dried to obtain the tungsten-dopamine hydrochloride precursor.

[0034] (2) The tungsten-dopamine hydrochloride precursor was placed in a tube furnace for carburizing treatment. Under a nitrogen atmosphere, the temperature was raised to 900°C at a heating rate of 1°C / min and held for 1 hour to obtain tungsten carbide.

[0035] (3) Tungsten carbide was added to a 0.15 mol / L nickel nitrate solution. After ultrasonic treatment, the mixture was placed in a low-temperature reactor, and a 0.30 mol / L sodium borohydride solution was slowly added under a continuous nitrogen atmosphere. The mixture was then allowed to stand at room temperature. Finally, it was filtered, washed, and dried to obtain nickel-based tungsten carbide, denoted as Ni. 0.15 @WC-0.5;

[0036] (4) Add 5-HMF and the Ni obtained in step (3) 0.15 @WC-0.5 and solvent are mixed and placed in a sealed high-pressure reactor. The air is replaced with hydrogen, and hydrogen is used as the hydrogen donor. The hydrogenation reaction is carried out at a hydrogen pressure of 2 MPa.

[0037] The Ni obtained in this embodiment 0.15 The product analysis of the hydrogenation of 5-HMF catalyzed by @WC-0.5 under different reaction conditions is shown in Table 1:

[0038] Table 1: Ni obtained in Example 1 0.15 Product analysis table of 5-HMF hydrogenation catalyzed by @WC-0.5 under different reaction conditions

[0039]

[0040]

[0041] Example 2

[0042] A method for selective hydrogenation of 5-HMF catalyzed by nickel-based transition metal carbides, comprising the following specific steps:

[0043] (1) Dopamine hydrochloride and ammonium metatungstate in a mass ratio of 1:1 were dissolved in deionized water and stirred to form a tungsten-dopamine hydrochloride complex. Ethanol was added to the above solution and ammonia was added rapidly while stirring. The mixture was stirred continuously at room temperature. The precipitate was collected by centrifugation, filtered, washed and dried to obtain the tungsten-dopamine hydrochloride precursor.

[0044] (2) The tungsten-dopamine hydrochloride precursor was placed in a tube furnace for carburizing treatment. Under a nitrogen atmosphere, the temperature was raised to 900°C at a heating rate of 2°C / min and held for 2 hours to obtain tungsten carbide.

[0045] (3) Tungsten carbide was added to a 0.15 mol / L nickel chloride solution. After ultrasonic treatment, the mixture was placed in a low-temperature reactor, and a 0.40 mol / L sodium borohydride solution was slowly added under a continuous nitrogen atmosphere. The mixture was then allowed to stand at room temperature. Finally, it was filtered, washed, and dried to obtain nickel-based tungsten carbide, denoted as Ni. 0.15 @WC-1;

[0046] (4) Add 5-HMF and the Ni obtained in step (3) 0.15 @WC-1 and solvent are mixed and placed in a sealed high-pressure reactor. The air is replaced with hydrogen, and hydrogen is used as the hydrogen donor. The hydrogenation reaction is carried out at a hydrogen pressure of 2 MPa.

[0047] The Ni obtained in this embodiment 0.15 The product analysis of 5-HMF hydrogenation catalyzed by @WC-1 under different reaction conditions is shown in Table 2:

[0048] Table 2: Ni obtained in Example 2 0.15 Product analysis table of 5-HMF hydrogenation catalyzed by @WC-1 under different reaction conditions

[0049]

[0050] Example 3

[0051] A method for selective hydrogenation of 5-HMF catalyzed by nickel-based transition metal carbides, comprising the following specific steps:

[0052] (1) Dopamine hydrochloride and ammonium metatungstate in a mass ratio of 1:2 were dissolved in deionized water and stirred to form a tungsten-dopamine hydrochloride complex. Ethanol was added to the above solution and ammonia was added rapidly while stirring. The mixture was stirred continuously at room temperature. The precipitate was collected by centrifugation, filtered, washed and dried to obtain the tungsten-dopamine hydrochloride precursor.

[0053] (2) The tungsten-dopamine hydrochloride precursor was placed in a tube furnace for carburizing treatment. Under a nitrogen atmosphere, the temperature was raised to 900°C at a heating rate of 5°C / min and held for 2 hours to obtain tungsten carbide.

[0054] (3) Tungsten carbide was added to a 0.15 mol / L nickel sulfate solution. After ultrasonic treatment, the mixture was placed in a low-temperature reactor, and a 0.50 mol / L sodium borohydride solution was slowly added under a continuous nitrogen atmosphere. The mixture was then allowed to stand at room temperature. Finally, it was filtered, washed, and dried to obtain nickel-based tungsten carbide, denoted as Ni. 0.15 @WC-2;

[0055] (4) Add 5-HMF and the Ni obtained in step (3) 0.15 @WC-2 and solvent are mixed and placed in a sealed high-pressure reactor. The air is replaced with hydrogen, and hydrogen is used as the hydrogen donor. The hydrogenation reaction is carried out at a hydrogen pressure of 2 MPa.

[0056] The Ni obtained in this embodiment 0.15 The product analysis of the hydrogenation of 5-HMF catalyzed by @WC-2 under different reaction conditions is shown in Table 3:

[0057] Table 3: Ni obtained in Example 3 0.15 Product analysis table of 5-HMF hydrogenation catalyzed by @WC-2 under different reaction conditions

[0058]

[0059] Example 4

[0060] A method for selective hydrogenation of 5-HMF catalyzed by nickel-based transition metal carbides, comprising the following specific steps:

[0061] (1) Dopamine hydrochloride and ammonium metatungstate in a mass ratio of 1:1 were dissolved in deionized water and stirred to form a tungsten-dopamine hydrochloride complex. Ethanol was added to the above solution and ammonia was added rapidly while stirring. The mixture was stirred continuously at room temperature. The precipitate was collected by centrifugation, filtered, washed and dried to obtain the tungsten-dopamine hydrochloride precursor.

[0062] (2) The tungsten-dopamine hydrochloride precursor was placed in a tube furnace for carburizing treatment. Under a nitrogen atmosphere, the temperature was raised to 900°C at a heating rate of 1°C / min and held for 8 hours to obtain tungsten carbide.

[0063] (3) Tungsten carbide was added to a 0.30 mol / L nickel nitrate solution. After ultrasonic treatment, the mixture was placed in a low-temperature reactor, and a 0.50 mol / L sodium borohydride solution was slowly added under a continuous nitrogen atmosphere. The mixture was then allowed to stand at room temperature. Finally, it was filtered, washed, and dried to obtain nickel-based tungsten carbide, denoted as Ni. 0.30 @WC-1;

[0064] (4) Add 5-HMF and the Ni obtained in step (3) 0.30 @WC-1 and solvent are mixed and placed in a sealed high-pressure reactor. The air is replaced with hydrogen, and hydrogen is used as the hydrogen donor. The hydrogenation reaction is carried out at a hydrogen pressure of 2 MPa.

[0065] The Ni obtained in this embodiment 0.30 The product analysis of @WC-1 catalyzing the hydrogenation of 5-HMF under different reaction conditions is shown in Table 4:

[0066] Table 4: Ni obtained in Example 4 0.30 Product analysis table of 5-HMF hydrogenation catalyzed by @WC-1 under different reaction conditions

[0067]

[0068] Example 5

[0069] A method for selective hydrogenation of 5-HMF catalyzed by nickel-based transition metal carbides, comprising the following specific steps:

[0070] (1) Dissolve dopamine hydrochloride and ammonium metavanadate in deionized water in a mass ratio of 1:1, stir to form vanadium-dopamine hydrochloride complex, add ethanol to the above solution, and add ammonia water quickly while stirring. Stir continuously at room temperature, collect the precipitate by centrifugation, filter, wash and dry to obtain vanadium-dopamine hydrochloride precursor.

[0071] (2) The vanadium-dopamine hydrochloride precursor was placed in a tube furnace for carburizing treatment. Under a nitrogen atmosphere, the temperature was increased to 1000℃ at a heating rate of 1℃ / min and held for 8h to obtain vanadium carbide.

[0072] (3) Vanadium carbide was added to a 0.30 mol / L nickel nitrate solution. After ultrasonic treatment, the mixture was placed in a low-temperature reactor, and a 0.50 mol / L sodium borohydride solution was slowly added under a continuous nitrogen atmosphere. The mixture was then allowed to stand at room temperature. Finally, it was filtered, washed, and dried to obtain nickel-based vanadium carbide, denoted as Ni. 0.30 @VC-1;

[0073] (4) Add 5-HMF and the Ni obtained in step (3) 0.30@VC-1 and solvent are mixed and placed in a sealed high-pressure reactor. The air is replaced with hydrogen, and hydrogen is used as the hydrogen donor. The hydrogenation reaction is carried out at a hydrogen pressure of 2 MPa.

[0074] The Ni obtained in this embodiment 0.30 The product analysis of 5-HMF hydrogenation catalyzed by @VC-1 under different reaction conditions is shown in Table 5:

[0075] Table 5: Ni obtained in Example 5 0.30 Product analysis table of 5-HMF hydrogenation catalyzed by @VC-1 under different reaction conditions

[0076]

[0077] Example 6

[0078] A method for selective hydrogenation of 5-HMF catalyzed by nickel-based transition metal carbides, comprising the following specific steps:

[0079] (1) Dopamine hydrochloride and ammonium molybdate in a mass ratio of 1:1 were dissolved in deionized water and stirred to form a molybdenum-dopamine hydrochloride complex. Ethanol was added to the above solution and ammonia was added rapidly while stirring. The mixture was stirred continuously at room temperature. The precipitate was collected by centrifugation, filtered, washed and dried to obtain the molybdenum-dopamine hydrochloride precursor.

[0080] (2) The molybdenum-dopamine hydrochloride precursor was placed in a tube furnace for carburizing treatment. Under a nitrogen atmosphere, the temperature was increased to 1100℃ at a heating rate of 1℃ / min and held for 8h to obtain molybdenum carbide.

[0081] (3) Molybdenum carbide was added to a 0.30 mol / L nickel nitrate solution. After ultrasonic treatment, the mixture was placed in a low-temperature reactor, and a 0.50 mol / L sodium borohydride solution was slowly added under a continuous nitrogen atmosphere. The mixture was then allowed to stand at room temperature. Finally, it was filtered, washed, and dried to obtain nickel-based molybdenum carbide, denoted as Ni. 0.30 @MoC-1;

[0082] (4) Add 5-HMF and the Ni obtained in step (3) 0.30 @MoC-1 and solvent are mixed and placed in a sealed high-pressure reactor. The air is replaced with hydrogen, and hydrogen is used as the hydrogen donor. The hydrogenation reaction is carried out at a hydrogen pressure of 2 MPa.

[0083] The Ni obtained in this embodiment 0.30 The product analysis of @MoC-1 catalyzing the hydrogenation of 5-HMF under different reaction conditions is shown in Table 6:

[0084] Table 6: Ni obtained in Example 6 0.30Product analysis table of 5-HMF hydrogenation catalyzed by @MoC-1 under different reaction conditions

[0085]

[0086] Example 7

[0087] A method for selective hydrogenation of 5-HMF catalyzed by copper-based transition metal carbides, comprising the following specific steps:

[0088] (1) Dopamine hydrochloride and ammonium metatungstate in a mass ratio of 1:1 were dissolved in deionized water and stirred to form a tungsten-dopamine hydrochloride complex. Ethanol was added to the above solution and ammonia was added rapidly while stirring. The mixture was stirred continuously at room temperature. The precipitate was collected by centrifugation, filtered, washed and dried to obtain the tungsten-dopamine hydrochloride precursor.

[0089] (2) The tungsten-dopamine hydrochloride precursor was placed in a tube furnace for carburizing treatment. Under a nitrogen atmosphere, the temperature was raised to 900°C at a heating rate of 1°C / min and held for 8 hours to obtain tungsten carbide.

[0090] (3) Tungsten carbide was added to a 0.30 mol / L copper nitrate solution. After ultrasonic treatment, the mixture was placed in a low-temperature reactor, and a 0.50 mol / L sodium borohydride solution was slowly added under a continuous nitrogen atmosphere. The mixture was then allowed to stand at room temperature. Finally, copper-based tungsten carbide was obtained by filtration, washing, and drying, denoted as Cu. 0.30 @WC-1;

[0091] (4) Add 5-HMF and Cu obtained in step (3) 0.30 @WC-1 and solvent are mixed and placed in a sealed high-pressure reactor. The air is replaced with hydrogen, and hydrogen is used as the hydrogen donor. The hydrogenation reaction is carried out at a hydrogen pressure of 2 MPa.

[0092] The Cu obtained in this embodiment 0.30 The product analysis of @WC-1 catalyzing the hydrogenation of 5-HMF under different reaction conditions is shown in Table 7:

[0093] Table 7: Cu obtained in Example 7 0.30 Product analysis table of 5-HMF hydrogenation catalyzed by @WC-1 under different reaction conditions

[0094]

[0095]

[0096] Example 8

[0097] A method for selective hydrogenation of 5-HMF catalyzed by iron-based transition metal carbides, comprising the following specific steps:

[0098] (1) Dopamine hydrochloride and ammonium metatungstate in a mass ratio of 1:1 were dissolved in deionized water and stirred to form a tungsten-dopamine hydrochloride complex. Ethanol was added to the above solution and ammonia was added rapidly while stirring. The mixture was stirred continuously at room temperature. The precipitate was collected by centrifugation, filtered, washed and dried to obtain the tungsten-dopamine hydrochloride precursor.

[0099] (2) The tungsten-dopamine hydrochloride precursor was placed in a tube furnace for carburizing treatment. Under a nitrogen atmosphere, the temperature was raised to 900°C at a heating rate of 1°C / min and held for 8 hours to obtain tungsten carbide.

[0100] (3) Tungsten carbide was added to a 0.30 mol / L ferric nitrate solution. After ultrasonic treatment, the mixture was placed in a low-temperature reactor, and a 0.50 mol / L sodium borohydride solution was slowly added under a continuous nitrogen atmosphere. The mixture was then allowed to stand at room temperature. Finally, iron-based tungsten carbide was obtained by filtration, washing, and drying, denoted as Fe. 0.30 @WC-1;

[0101] (4) Add 5-HMF and Fe obtained in step (3) 0.30 @WC-1 and solvent are mixed and placed in a sealed high-pressure reactor. The air is replaced with hydrogen, and hydrogen is used as the hydrogen donor. The hydrogenation reaction is carried out at a hydrogen pressure of 2 MPa.

[0102] The Fe obtained in this embodiment 0.30 The product analysis of @WC-1 catalyzing the hydrogenation of 5-HMF under different reaction conditions is shown in Table 8:

[0103] Table 8: Fe obtained in Example 8 0.30 Product analysis table of 5-HMF hydrogenation catalyzed by @WC-1 under different reaction conditions

[0104]

[0105] Example 9

[0106] A method for selective hydrogenation of 5-HMF catalyzed by cobalt-based transition metal carbides, comprising the following specific steps:

[0107] (1) Dopamine hydrochloride and ammonium metatungstate in a mass ratio of 1:1 were dissolved in deionized water and stirred to form a tungsten-dopamine hydrochloride complex. Ethanol was added to the above solution and ammonia was added rapidly while stirring. The mixture was stirred continuously at room temperature. The precipitate was collected by centrifugation, filtered, washed and dried to obtain the tungsten-dopamine hydrochloride precursor.

[0108] (2) The tungsten-dopamine hydrochloride precursor was placed in a tube furnace for carburizing treatment. Under a nitrogen atmosphere, the temperature was raised to 900°C at a heating rate of 1°C / min and held for 8 hours to obtain tungsten carbide.

[0109] (3) Tungsten carbide was added to a 0.30 mol / L cobalt nitrate solution. After ultrasonic treatment, the mixture was placed in a low-temperature reactor, and a 0.50 mol / L sodium borohydride solution was slowly added under a continuous nitrogen atmosphere. The mixture was then allowed to stand at room temperature. Finally, it was filtered, washed, and dried to obtain cobalt-based tungsten carbide, denoted as Co. 0.30 @WC-1;

[0110] (4) Add 5-HMF and the Co obtained in step (3) 0.30 @WC-1 and solvent are mixed and placed in a sealed high-pressure reactor. The air is replaced with hydrogen, and hydrogen is used as the hydrogen donor. The hydrogenation reaction is carried out at a hydrogen pressure of 2 MPa.

[0111] The Co obtained in this embodiment 0.30 The product analysis of @WC-1 catalyzing the hydrogenation of 5-HMF under different reaction conditions is shown in Table 9:

[0112] Table 9: Co obtained in Example 9 0.30 Product analysis table of 5-HMF hydrogenation catalyzed by @WC-1 under different reaction conditions

[0113]

[0114] In summary, the comparison of Examples 1-9 shows that the selectivity of nickel-based transition metal carbide catalysts in the selective hydrogenation regulation of 5-HMF can reach as high as 81.1%, 48.6%, 36.6% and 97.7% for BHMF, MF, MFA and DMF respectively, which is far higher than that of other metal-based transition metal carbide catalysts.

[0115] Figure 1 For the product analysis of each reaction stage in Example 4 at the same temperature, in Ni 0.30 Under @WC-1 conditions, 5-HMF can be rapidly converted to BHMF, MF, and MFA within 1 hour, and exhibits high selectivity for DMF as the reaction continues. Based on these experimental results, the reaction pathway for the selective hydrogenation of 5-HMF is as follows: Figure 2 As shown, Ni 0.30@WC-1 exhibits excellent adsorption and catalytic performance for both aldehyde and hydroxymethyl groups of 5-HMF, avoiding excessive hydrogenation of the furan ring. This allows for the development of two routes: preferential hydrogenation to synthesize BHMF and MF. Continuous hydrogenation yields DMF, demonstrating that the dual-effect hydrogenation performance of nickel-based transition metal carbides can effectively control the formation of hydrogenation products. Furthermore, the tungsten carbide and Ni obtained in Example 4 were also analyzed. 0.30 @WC-1 was characterized by NH3-TPD and XPS. Figure 3 The Ni-supported catalyst exhibits distinct diffraction peaks in both the low-temperature (<250℃) and high-temperature (500-800℃) regions, indicating the coexistence of weak and strong acid sites and a significantly increased acid content. This further reveals a direct correlation between acid strength and content and catalytic activity, as demonstrated by Py-FTIR characterization results. Figure 4 This indicates that the acidic site behaves as a Lewis acid site, effectively promoting the hydrogenation reaction. (From...) Figure 5-6 It can be seen that Ni 2p 3 / 2光谱 The three diffraction peaks shown are attributed to Ni bonded to metallic nickel. 0 Ni oxide / nickel hydroxide 2+ The satellite peaks and the diffraction peaks in the W 4f spectrum represent the W 4f peaks bonded to metallic tungsten. 4+ W 6+ and WC bond, and Ni 0.30 The @WC-1 shows a shift of -0.2 eV, which strongly suggests that it has stronger electron-rich metal sites, which is beneficial for hydrogen activation and CO bond breaking, thereby accelerating the hydrogenolysis process.

[0116] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. Use of a nickel-based transition metal carbide catalyst in the selective hydrogenation of 5-HMF, characterized in that: Nickel-based transition metal carbides were used as hydrogenation catalysts, with hydrogen as the hydrogen source, and 5-hydroxymethylfurfural was selectively hydrogenated at 160-190℃ for 0.5-3h to produce 2,5-furandiethanol, 5-methylfurfural, 5-methyl-2-furanethanol, and 2,5-dimethylfuran. The preparation method of the nickel-based transition metal carbide catalyst includes the following steps: first, using dopamine hydrochloride and a metal complex salt as raw materials, dissolving them in deionized water to form a metal-dopamine hydrochloride complex; then, adding ethanol and ammonia to the complex and stirring, collecting the precipitate to obtain a metal-dopamine hydrochloride precursor; next, carbonizing the metal-dopamine hydrochloride precursor to obtain a transition metal carbide; then, adding the transition metal carbide to a nickel compound solution and ultrasonically treating it; finally, at a low temperature... Under a nitrogen atmosphere, sodium borohydride solution is added, and after standing at room temperature, it is filtered, washed, and dried to obtain nickel-based transition metal carbides. Among them, the metal complex salt is one of ammonium metatungstate, ammonium metavanadate, and ammonium molybdate; the mass ratio of dopamine hydrochloride to the metal complex salt is 1:0.5-2; the nickel compound is one of nickel nitrate, nickel chloride, and nickel sulfate, and the concentration of the nickel compound in an aqueous solution is 0.15-0.30 mol / L; the concentration of the added sodium borohydride solution is 0.30-0.50 mol / L.

2. Use according to claim 1, characterized in that, The carbonization process involves heating the gas to 900-1100°C at a rate of 1-5°C / min under a nitrogen atmosphere and holding it at that temperature for 1-8 hours.

3. Use according to claim 1 or 2, characterized in that, The specific preparation steps of the catalyst are as follows: (1) Dissolve dopamine hydrochloride and metal complex salt in deionized water in a mass ratio of 1:0.5-2, stir to form metal-dopamine hydrochloride complex, add ethanol to the above solution, and add ammonia water quickly while stirring. Stir continuously at room temperature, collect the precipitate by centrifugation, filter, wash and dry to obtain metal-dopamine hydrochloride precursor. (2) The metal-dopamine hydrochloride precursor was placed in a tube furnace and heated to 900-1100℃ at a heating rate of 1-5℃ / min under a nitrogen atmosphere, and held for 1-8h to perform carbonization treatment to obtain transition metal carbides. (3) The transition metal carbide is added to any one of nickel nitrate, nickel chloride, or nickel sulfate solutions with a concentration of 0.15-0.30 mol / L and mixed thoroughly. The resulting mixture is ultrasonically treated and then placed in a low-temperature reactor. A sodium borohydride solution with a concentration of 0.30-0.50 mol / L is slowly added under a continuous nitrogen atmosphere. The mixture is then allowed to stand at room temperature. Finally, it is filtered, washed, and dried to obtain nickel-based transition metal carbides.

Images