Preparation method of nickel-based catalyst and application of nickel-based catalyst in regulation and control of distribution of 5-hydroxymethylfurfural hydrogenation product
By preparing NiCe and NiZn0.1Ce catalysts, the electron transfer ability of the catalyst is regulated, and the problem of low selectivity of nickel-based catalysts under mild conditions is solved, and BHMF and BHMTHF are efficiently generated, with good stability and recovery.
Patent Information
- Application Number
- CN202411511522.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2025-02-07
AI Technical Summary
In the prior art, nickel-based catalysts have problems such as low selectivity and catalyst deactivation when catalyzing the 5-hydroxymethylfurfural hydrogenation reaction, and it is difficult to efficiently generate 2,5-bis(hydroxymethyl)furan under mild conditions. (BHMF) and 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF).
NiCe and NiZn0.1Ce catalysts are used to control the load amount of nickel oxide and the ratio of Zn added to regulate the electron transfer capacity of the catalyst, thereby achieving selective hydrogenation of 5-hydroxymethylfurfural under mild conditions.
It realizes the high selective generation of BHMF and BHMTHF under mild conditions, and the catalyst is stable, recyclable, and has low cost, which is suitable for industrial applications.
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Abstract
Description
Technical Field
[0001] The invention belongs to the field of biomass catalytic conversion, and specifically relates to a method for preparing a nickel-based catalyst and an application of the catalyst in regulating the distribution of 5-hydroxymethylfurfural hydrogenation products. Background Art
[0002] Directly utilizing renewable biomass resources to produce high value-added chemicals can reduce dependence on fossil resources and thus has attracted widespread attention. At present, 5-hydroxymethylfurfural is an important biomass-based platform compound that can be prepared by hydrolysis of glucose, fructose and sucrose. It contains C-OH, C=O and furan ring structures and can be converted into various high-value derivatives by catalytic hydrogenation. Such as 2,5-di(hydroxymethyl)furan (BHMF) and 2,5-di(hydroxymethyl)tetrahydrofuran (BHMTHF), which have important applications in pharmaceutical intermediates and polymer products.
[0003] A lot of work has been done on the development of catalysts for hydrogenation of 5-hydroxymethylfurfural to furandiol. Precious metal catalysts such as Ru / C and Pt / MCM-41 can efficiently catalyze the selective hydrogenation of HMF to produce BHMF. Fulignati et al. found that Ru / C can highly selectively hydrogenate furandiol to obtain 93.0% BHMF (3MPa, 50℃) and 95.3% BHMTHF (5MPa, 50℃) yields. However, due to its high price, it is not suitable for large-scale production, which also limits its wide application in industrial production.
[0004] Transition metal Ni-based catalysts are cheap, readily available, and have good catalytic performance. They are considered to be potential alternatives to precious metal catalysts, but they are also accompanied by problems such as low selectivity and catalyst deactivation. For example, using RaneyNi under reaction conditions of 4MPa and 120°C, a higher BHMTHF yield (92.0%) was obtained due to the hydrogenation of both the furan ring and the aldehyde group of HMF. However, single metal nickel catalysts are easily leached in methanol media, resulting in poor reusability. The strong π adsorption mode of HMF on Ni makes its hydrogenation activity high, but its selectivity for BHMF is not high. Therefore, it is an extremely attractive challenge to develop efficient, stable, and environmentally friendly non-precious metal nickel-based catalysts to achieve the selective and on-demand hydrogenation of HMF to BHMF or BHMTHF under mild conditions. Summary of the invention
[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a method for preparing a nickel-based catalyst and its application in preparing BHMTHF and BHMF by hydrogenation of 5-hydroxymethylfurfural. The catalyst can effectively control the distribution of the two products, and is a non-precious metal catalyst, low in cost, non-toxic, simple in preparation method, high in stability, and can react under mild conditions and has good activity.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions:
[0007] (1) Preparation of metal precursor solution: First, dissolve nickel nitrate, cerium nitrate and zinc nitrate in deionized water and stir well to obtain a mixed solution A; dissolve citric acid in deionized water and stir well to obtain a mixed solution B; slowly pour solution B into solution A and stir to ensure that the solutions are evenly mixed.
[0008] (2) evaporating the mixed solution obtained in step (1) in a water bath at 70° C. until a uniform and transparent gel is formed;
[0009] (3) The gel obtained in step (2) is transferred to a muffle furnace and calcined in air at 700° C. to obtain NiCe and NiZnCe catalyst precursors.
[0010] (4) grinding the solid obtained in step (3) into powder, placing it in a quartz boat, reducing it by programmed temperature in a hydrogen atmosphere, and naturally cooling it to room temperature to obtain NiCe and NiZnCe catalysts;
[0011] Preferably, in step (1), the loading amount of nickel oxide is controlled to be in the range of 5 wt % to 30 wt %, and the loading amount of nickel oxide = {nickel oxide / (nickel oxide + cerium oxide)}×100%.
[0012] Preferably, the optimal addition ratio of the nickel nitrate, cerium nitrate, zinc nitrate, citric acid and deionized water is 0.005 mol: 0.0075 mol: 0.0005 mol: 0.021 mol: 50 mL.
[0013] The stirring time in step (1) is 0.1-1h.
[0014] Preferably, the calcination process in step (3) is: heating to 700° C. at a heating rate of 2° C. / min in a muffle furnace, maintaining for 4 hours, and naturally cooling to room temperature.
[0015] Preferably, the reduction process in step (4) is: heating to 400° C. at a heating rate of 2° C. / min in a tubular furnace filled with hydrogen, maintaining for 3 h, and naturally cooling to room temperature.
[0016] Furthermore, the method for catalyzing the hydrogenation reaction of 5-hydroxymethylfurfural using a Ni-based catalyst specifically comprises the following steps:
[0017] 5-Hydroxymethylfurfural, isopropanol and NiCe / NiZn 0.1Ce catalyst is added into an intermittent closed high-pressure reactor, heated to a specified temperature and stirred for reaction under a certain pressure of hydrogen atmosphere to obtain the corresponding hydrogenation product; after the reaction is completed, it is cooled to room temperature in a water bath, the pressure is released, and the obtained reaction liquid is centrifuged and sampled for analysis.
[0018] Preferably, in the method for catalyzing the hydrogenation reaction of 5-hydroxymethylfurfural with a Ni-based catalyst, the mass ratio of 5-hydroxymethylfurfural, catalyst and isopropanol is 0.06:0.03:2, the reaction temperature is 110-170°C (preferably 150°C), the hydrogen pressure atmosphere is 0.7-2.7MPa (preferably 1.2MPa), and the reaction time is 0.5-4h (preferably 3h).
[0019] After separation, the catalyst was washed three times with deionized water and anhydrous ethanol alternately, and dried at 40°C for 12 h for subsequent cyclic reactions. Compared with the prior art, the present invention has the following beneficial effects:
[0020] (1) The NiCe catalyst used in the present invention utilizes the high dispersion of Ni on the CeO2 carrier to achieve full hydrogenation of the furan ring and aldehyde group on 5-hydroxymethylfurfural under mild conditions to generate 2,5-di(hydroxymethyl)tetrahydrofuran (BHMTHF) with high selectivity. 0.1 Ce catalyst uses the electron transfer energy between Ni and Zn to inhibit the hydrogenation of the furan ring on 5-hydroxymethylfurfural, and only the aldehyde group is hydrogenated to produce 2,5-di(hydroxymethyl)furan (BHMF).
[0021] (2) Compared with precious metal catalysts, the nickel-based catalyst prepared by the present invention has cheap raw materials, simple preparation methods, mild reaction conditions, good stability and recyclability, low equipment requirements, simple operation, high product selectivity, and broad market application prospects. The catalyst does not need to be regenerated, but can be recycled after drying, and the yield remains basically unchanged, which has obvious advantages. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 Schematic diagram of the reaction of 5-hydroxymethylfurfural hydrogenation catalyzed by the catalyst used in Example 1.
[0023] Figure 2 This is an activity data diagram of the catalyst used in Example 1.
[0024] Figure 3 is the XRD pattern of the catalyst used in Example 1.
[0025] Figure 4 This is a graph showing the cycle performance of the catalyst used in Example 1 during the reaction. Specific implementation examples
[0026] In order to facilitate the understanding of the present invention, the technical solution of the present invention is described in detail below in conjunction with specific embodiments and drawings of the specification. These embodiments are only used to illustrate the present invention and do not limit the scope of protection claimed in the present invention.
[0027] Example 1: NiCe and NiZn 0.1 The preparation method of Ce catalyst is as follows:
[0028] (1): Preparation of NiCe catalyst metal precursor solution: Dissolve 0.005 mol nickel nitrate and 0.0075 mol cerium nitrate in 25 mL deionized water to obtain mixed solution A; dissolve 0.018 mol citric acid in 25 mL deionized water to obtain mixed solution B, and stir to ensure that the solutions are evenly mixed. NiZn 0.1 The preparation steps of the Ce catalyst metal precursor solution are the same as above, and 0.0005 mol of zinc nitrate is added to solution A, and the content of citric acid added is 0.019 mol.
[0029] (2) evaporating the obtained mixed solution in a water bath at 70° C. until a uniform and transparent gel is formed;
[0030] (3) transferring the obtained gel to a muffle furnace, heating the mixture to 700° C. at a heating rate of 2° C. / min, calcining the mixture for 4 h, and grinding the mixture into powder to obtain a catalyst precursor;
[0031] (4) The catalyst precursor was heated to 400°C at a heating rate of 2°C / min in a hydrogen atmosphere for 3 h, and then naturally cooled to room temperature to finally obtain NiCe and NiZn 0.1 Ce catalyst.
[0032] Catalyst structure characterization
[0033] Figure 2 NiCe and NiZn prepared in Example 1 0.1 The X-ray diffraction pattern of the Ce catalyst was analyzed. By comparing with the PDF card database, the diffraction pattern of the catalyst can be well matched with the PDF cards of NiO and CeO2 (JCPDS, PDF#44-1159, PDF#43-1002). The XRD results show that the cerium oxide-supported nickel catalyst has been successfully prepared. No diffraction peak of ZnO can be detected in the XRD spectrum, indicating that ZnO is uniformly dispersed and the addition of a small amount of Zn has no effect on the bulk structure of the catalyst.
[0034] Catalyst activity test
[0035] The experimental reaction was carried out in a 10mL stainless steel autoclave with a magnetic stirrer. 60mg 5-hydroxymethylfurfural, 30mg catalyst, and 3mL isopropanol were added to the reactor lining, 1.2MPaH2 was filled, and the reactor was sealed. During the reaction, the speed of the magnetic stirrer was set to 1000rpm, the reaction temperature was set to 150℃, and the reaction was carried out for 3h. After the reaction was completed, the reactor was taken out and placed in an ice water bath to cool to room temperature. After the reactor was depressurized, the obtained reaction liquid was centrifuged. The reaction activity of the catalyst was qualitatively and quantitatively analyzed using gas chromatography, and the conversion rate of 5-hydroxymethylfurfural, the selectivity of 2,5-di(hydroxymethyl)tetrahydrofuran, and the selectivity of 2,5-di(hydroxymethyl)furan were calculated to be 100%, 95.3%, and 94.1%, respectively.
[0036] Catalyst cycle performance test
[0037] Example 1 After the reaction, the reaction liquid was centrifuged to separate the catalyst, and the recovered catalyst was washed three times with deionized water and anhydrous ethanol alternately, dried at 40° C. for 12 h, and then put into the next reaction.
[0038] Figure 3 The figure is a cycle performance diagram of the catalyst prepared in Example 1. The results show that after the two catalysts prepared in Example 1 were reused five times in the reaction, the catalytic activity only decreased very slightly, showing good repeatability and stability.
[0039] Example 2
[0040] The effect of reaction temperature on HMF conversion and selectivity was studied. 0.1 Ce catalyst (30 mg), HMF (0.5 mmol), and isopropanol (3 mL) were added to the autoclave, which was sealed and filled and discharged with H2 several times to replace the air in the autoclave. After the filling and discharging, the H2 was pressurized to 1.2 MPa, and then the autoclave was heated from room temperature to the set temperature, and stirred at a rate of 1000 r / min for 3 hours under magnetic stirring. The results showed that at low temperatures, the NiCe catalyst was not completely converted, and the intermediate product BHMF was not completely converted to BHMTHF. High temperature was more conducive to the conversion of HMF. At 150°C, the HMF conversion rate was 100%, and a BHMTHF selectivity of 95.3% was obtained. For NiZn 0.1 Ce catalyst also has similar results. At low temperature, HMF cannot be completely converted and BHMF selectivity is low. At 170°C, HMF conversion rate is 100% and BHMF selectivity is 96.4%. The details are shown in the following table: Table 1 Preparation of BHMTHF by hydrogenation of HMF over NiCe catalyst at different temperatures Table 2 NiZn at different temperatures 0.1 Preparation of BHMF by Hydrogenation of HMF over Ce Catalyst
Claims
1. A method for preparing a nickel-based catalyst and its application in regulating the distribution of 5-hydroxymethylfurfural hydrogenation products, the specific features of which are as follows: In isopropanol solution, 5-hydroxymethylfurfural and nickel-based catalyst were added under hydrogen conditions and reacted at 150°C for 3h to obtain 2,5-dihydroxymethyltetrahydrofuran on NiCe catalyst and 2,5-dihydroxymethyltetrahydrofuran on NiZn 0.1 2,5-dihydroxymethylfuran was obtained over Ce catalyst; The specific preparation method of the catalyst comprises the following steps: S1: dissolve a certain amount of nickel salt, cerium salt and zinc salt in deionized water, stir evenly to obtain a mixed solution A; dissolve the coagulant citric acid in deionized water, stir evenly to obtain a mixed solution B; slowly pour solution B into solution A, stir to ensure that the solutions are evenly mixed; wherein the anion of the metal nickel salt is any one of nitrate, phosphate, chlorate and sulfate, the anion of the metal cerium salt is any one of nitrate, phosphate, chlorate and sulfate, and the anion of the metal zinc salt is any one of nitrate, phosphate, chlorate and sulfate. S2: Evaporate the mixed solution in a water bath at 60-90°C until a uniform and transparent gel is formed; transfer the obtained gel to a muffle furnace, heat the temperature to 400-700°C at a heating rate of 2°C / min-10°C / min, and calcine for 2-5h, cool naturally to room temperature, grind the obtained solid into powder to obtain NiCe or NiZnCe catalyst precursor, and heat the precursor in a hydrogen atmosphere at a flow rate of 70ml / min and a heating rate of 2°C / min-10°C / min to 400°C-700°C, maintain for 2-4h, and cool naturally to room temperature to obtain NiCe and NiZnCe solid catalysts.
2. The catalyst prepared according to claim 1 is applied to the process of preparing 2,5-dihydroxymethyltetrahydrofuran and 2,5-dihydroxymethylfuran by hydrogenation of 5-hydroxymethylfurfural, characterized in that: Weigh 10mg-60mg of any catalyst prepared in claim 1 and put it in a 10mL intermittent closed high-pressure reactor, weigh 0.5mmol-1mmol 5-hydroxymethylfurfural and 3mL solvent, fill with hydrogen to 0.5MPa-3MPa, set the stirring speed to 1000rmp, heat to 110℃-170℃, and react for 0.5h-5h. After the reaction is completed, quickly cool it in a cold water bath, and after the reactor is depressurized, centrifuge the obtained reaction liquid. After the catalyst after the catalytic reaction is separated, it is rinsed three times with deionized water and anhydrous ethanol alternately, dried at 40℃ for 12h, and used for subsequent cyclic reactions. S1: The solvent in the 5-hydroxymethylfurfural hydrogenation reaction in claim 2 is any one of methanol, ethanol, isopropanol, tetrahydrofuran, and cyclohexane.