A method for preparing gamma-valerolactone by catalyzing the hydrogenation of levulinic acid with molybdenum selenide
By using a molybdenum selenide catalyst to catalyze the hydrogenation of levulinic acid under mild conditions, the problem of low efficiency of existing non-precious metal catalysts has been solved, achieving efficient preparation and cost reduction of γ-valerol, which is suitable for industrial application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEILONGJIANG UNIV
- Filing Date
- 2024-01-25
- Publication Date
- 2026-06-26
Smart Images
Figure CN117986209B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for synthesizing γ-valerolactone. Background Technology
[0002] With the continuous exploitation of fossil fuel resources such as coal, oil, and natural gas, global fossil energy resources are becoming increasingly depleted, making the search for clean and renewable energy sources an urgent priority. Biomass, as a renewable and clean energy source, is a carbon resource that can replace fossil fuels in the conversion into gaseous, liquid, and solid fuels, as well as other chemical raw materials and products. Pre-treating biomass before its targeted conversion into fine chemicals or clean fuels is an effective way to efficiently utilize biomass resources. Leucylpropionic acid, produced by the hydrolysis of lignocellulose, is considered by the US Department of Energy (USDOE) to be one of the most important biomass platform molecules, with broad application prospects in the preparation of biofuels, polymers, and other chemicals. γ-valerolactone, prepared by hydrogenating levulinic acid, can be used as a biofuel, fuel additive, and green solvent, and related research has become a hot topic in the field of biorefining.
[0003]
[0004] Formula 1: Reaction formula for the hydrogenation of levulinic acid to produce γ-valerolactone
[0005] Currently, most reported catalytic systems for the hydrogenation of levulinic acid to γ-valerol are noble metal catalysts. However, their limited resources and high cost restrict their large-scale use. Therefore, the use of non-noble metal catalysts for the hydrogenation of levulinic acid to γ-valerol has attracted widespread attention in recent years. In patent CN116284824A, Feng Jian et al. added aspartic acid and a molybdenum source sequentially to a mixed solvent of water and DMF and dispersed them thoroughly. The mixture was heated and stirred under reflux at 100–180 °C for 1–24 h. After the reaction was complete, the mixture was cooled to room temperature. The resulting precipitate was filtered, washed, and dried to obtain an amino-containing matrix material. The amino-containing matrix material, aldehyde, and thioglycolic acid were added to DMF, and the reaction was continued at room temperature for 1–12 h to obtain a MOF catalyst. 2 g of this catalyst required 6 h at a temperature as high as 180 °C to quantitatively convert 10 mmol of levulinic acid to γ-valerol. In patent CN114950478A, Zhou Jinxia et al. disclosed a method for the hydrogenation of levulinic acid to prepare γ-valerol using a CuAgZr / GO composite material. With 100 mg of this catalyst, the reaction required 200 °C and 3 MPa to achieve complete conversion of 200 mg of levulinic acid while maintaining 100% selectivity for γ-valerol. In invention patent CN113101941A, Li Na et al. disclosed a method for preparing a cobalt-molybdenum catalyst and used it to catalyze the hydrogenation of levulinic acid to γ-valerol. With 0.1 g of this catalyst, the reaction was carried out at 2 MPa hydrogen atmosphere and heated at 190 °C for 6 h (magnetic stirring speed of 800 r / min), achieving a 98% selectivity for γ-valerol and a 100% conversion rate for 0.34 g of levulinic acid. In summary, although non-precious metal catalysts such as molybdenum-based, cobalt-based, and copper-based catalysts are relatively inexpensive, they still suffer from drawbacks such as low catalytic efficiency and demanding reaction conditions. Therefore, developing a novel non-precious metal catalyst to achieve efficient hydrogenation of levulinic acid to γ-valerol under mild conditions while reducing the production cost of γ-valerol has significant research value and application potential. Summary of the Invention
[0006] The purpose of this invention is to solve the problems of low catalytic efficiency and harsh reaction conditions in existing non-precious metal catalyst systems, and to provide a method for the highly selective preparation of γ-valerol by hydrogenation of levulinic acid under mild conditions.
[0007] The method for preparing γ-valerol by molybdenum selenide-catalyzed hydrogenation of levulinic acid according to the present invention is implemented according to the following steps:
[0008] Molybdenum selenide catalyst, levulinic acid, and solvent were placed in a high-pressure reactor as raw materials. The air in the high-pressure reactor was first replaced with hydrogen gas several times at room temperature. Then, hydrogen gas was continuously introduced until the pressure inside the high-pressure reactor reached 0.5–3.0 MPa. The reaction was carried out under magnetic stirring for 0.5–5.0 h at a temperature of 100–200 °C and a hydrogen atmosphere. The mixture was then cooled to room temperature, and the molybdenum selenide catalyst was separated to obtain γ-valerolactone.
[0009] The present invention provides a method for preparing γ-valerol using molybdenum selenide as a catalyst in a batch stainless steel reactor for the selective hydrogenation of levulinic acid to γ-valerol. The catalyst used in this invention is prepared under hydrothermal conditions. Due to the lamellar morphology of the molybdenum selenide catalyst, it exhibits abundant edge active sites, resulting in high activity and high selectivity in the hydrogenation of levulinic acid to γ-valerol.
[0010] The method for preparing γ-valerol using molybdenum selenide as a catalyst in this invention has the following beneficial effects:
[0011] 1. The molybdenum selenide catalyst used in this invention is low in cost and simple to prepare, overcoming the shortcomings of existing non-metallic catalyst systems such as low catalytic efficiency and harsh reaction conditions.
[0012] 2. This invention provides a novel method for preparing γ-valerol using a highly efficient molybdenum selenide catalyst. The catalyst has high activity and selectivity, and under mild reaction conditions, the conversion rate of levulinic acid and the selectivity of γ-valerol can both reach 100%.
[0013] 3. The method for preparing γ-valerol using a highly efficient molybdenum selenide catalyst provided by this invention is easy to implement for industrial production. Attached Figure Description
[0014] Figure 1 This is the XRD pattern of molybdenum selenide catalyst A prepared in Example 1;
[0015] Figure 2 Here is a scanning electron microscope image of the molybdenum selenide catalyst A prepared in Example 1;
[0016] Figure 3 This is the XRD pattern of molybdenum selenide catalyst B prepared in Example 15;
[0017] Figure 4 This is a scanning electron microscope image of molybdenum selenide catalyst B prepared in Example 15. Detailed Implementation
[0018] Specific Implementation Method 1: The method for preparing γ-valerol by hydrogenation of levulinic acid catalyzed by molybdenum selenide in this implementation method is carried out according to the following steps:
[0019] Molybdenum selenide catalyst, levulinic acid, and solvent were placed in a high-pressure reactor as raw materials. The air in the high-pressure reactor was first replaced with hydrogen gas several times at room temperature. Then, hydrogen gas was continuously introduced until the pressure inside the high-pressure reactor reached 0.5–3.0 MPa. The reaction was carried out under magnetic stirring for 0.5–5.0 h at a temperature of 100–200 °C and a hydrogen atmosphere. The mixture was then cooled to room temperature, and the molybdenum selenide catalyst was separated to obtain γ-valerolactone.
[0020] This embodiment enables the highly selective preparation of γ-valerol by catalyzing the hydrogenation of levulinic acid using molybdenum selenide under relatively mild conditions.
[0021] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the preparation method of the molybdenum selenide catalyst is as follows:
[0022] a. Place ammonium molybdate and selenium powder in deionized water at a molar ratio of 1:(2~2.1), add sodium borohydride solution dropwise, and then transfer to a hydrothermal reactor.
[0023] b. The sealed hydrothermal crystallization vessel is heated to 220°C and maintained for 24–60 h (hydrothermal reaction). After cooling to room temperature, the molybdenum selenide catalyst (A) is obtained after filtration, washing, and drying.
[0024] In this embodiment, the hydrothermal reaction time is preferably 48 hours.
[0025] The molybdenum selenide catalyst A prepared in this embodiment was characterized by XRD. Figure 1 The results showed that all characteristic diffraction peaks of catalyst A were consistent with the MoSe2 standard card, indicating that the sample was pure-phase molybdenum selenide; its SEM image ( Figure 2 The catalyst A sample prepared in this embodiment has a plate-like morphology, which can make catalyst A exhibit abundant edge active sites. This is beneficial to overcome the shortcomings of existing catalyst systems, such as low catalytic efficiency and harsh reaction conditions, and can significantly improve the conversion rate and selectivity of γ-valerolactone by hydrogenation of levulinic acid.
[0026] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 2 in that the molar ratio of ammonium molybdate and sodium borohydride in step a is 1:(3-6).
[0027] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method Two in that in step a, 0.62g of ammonium molybdate and 0.55g of selenium powder are placed in 75mL of deionized water.
[0028] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that the preparation method of the molybdenum selenide catalyst is as follows:
[0029] a. Place ammonium molybdate and selenium powder in deionized water at a molar ratio of 1:(2~2.1), add ethylenediamine dropwise, and then transfer to a hydrothermal reactor;
[0030] b. The sealed hydrothermal crystallization vessel is heated to 220°C and maintained for 24–60 h. After cooling to room temperature, the molybdenum selenide catalyst (B) is obtained after filtration, washing, and drying.
[0031] In this embodiment, the hydrothermal reaction time is preferably 48 hours.
[0032] The molybdenum selenide catalyst B prepared in this embodiment was characterized by XRD. Figure 3 The results showed that all characteristic diffraction peaks of catalyst B were consistent with the MoSe2 standard card, indicating that the sample was pure-phase molybdenum selenide; its SEM image ( Figure 4 The image shows that the catalyst B sample prepared in this embodiment has a plate-like morphology.
[0033] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that the molybdenum selenide catalyst accounts for 0.5% to 4.0% of the raw material by mass.
[0034] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that the solvent used is water.
[0035] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method One in that the volume ratio of levulinic acid to solvent is 1:5 to 8.
[0036] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method One in that hydrogen gas is introduced until the pressure inside the high-pressure reactor reaches 1.5 to 1.6 MPa.
[0037] Specific Implementation Method 10: This implementation method differs from Specific Implementation Method 9 in that the reaction is carried out under magnetic stirring at a temperature of 140-160°C and in a hydrogen atmosphere for 0.5-5.0 hours.
[0038] Example 1: This example describes a method for preparing γ-valerate by hydrogenation of levulinic acid catalyzed by molybdenum selenide, implemented according to the following steps:
[0039] 100 mg of molybdenum selenide catalyst A, 0.55 g of levulinic acid, and 3 mL of water were added as solvents to a 50 mL stainless steel reactor. The air in the reactor was replaced with hydrogen at room temperature, and hydrogen was continued to be introduced until the pressure in the reactor reached 1.5 MPa. The reactor was then heated under magnetic stirring and reacted at 160 °C in a hydrogen atmosphere for 3.0 h. The reactor was then cooled to room temperature, and the molybdenum selenide catalyst was separated to obtain γ-valerolactone.
[0040] The molybdenum selenide catalyst A described in this embodiment is prepared according to the following steps: (1) 0.62g of ammonium molybdate and 0.55g of selenium powder (with a molar ratio of molybdenum in ammonium molybdate to selenium in selenium powder of 1:2) are placed in 75mL of deionized water, and sodium borohydride solution (molar ratio of ammonium molybdate to sodium borohydride of 1:3) is added dropwise and then transferred to a hydrothermal reactor; (2) the sealed hydrothermal crystallization reactor is heated to 220°C, kept for 48h, cooled to room temperature, filtered, washed and dried to obtain molybdenum selenide catalyst A.
[0041] The molybdenum selenide catalyst A prepared in this embodiment was characterized by XRD. Figure 1 The results showed that all characteristic diffraction peaks of catalyst A were consistent with the MoSe2 standard card, indicating that the sample was pure-phase molybdenum selenide; its SEM image ( Figure 2 The catalyst A sample prepared in this embodiment has a plate-like morphology, which can make catalyst A exhibit abundant edge active sites. This is beneficial to overcome the shortcomings of existing catalyst systems, such as low catalytic efficiency and harsh reaction conditions, and can significantly improve the conversion rate and selectivity of γ-valerolactone by hydrogenation of levulinic acid.
[0042] When the amount of levulinic acid is 0.55g and the amount of catalyst is 100mg, after reacting at 160℃ and 1.6MPa for 3.0h, the conversion rate of levulinic acid and the selectivity of γ-valerolactone both reach 100%.
[0043] Example 2: This example differs from Example 1 in that the reaction was carried out at a pressure of 0.8 MPa and a temperature of 160°C for 3.0 h, while other conditions were the same as in Example 1.
[0044] In this embodiment, the conversion rate of levulinic acid was 8.8%, and the selectivity of γ-valerolactone was 100%.
[0045] Example 3: The difference between this example and Example 1 is that the reaction was carried out under magnetic stirring for 3.0 h at a pressure of 1.0 MPa, a temperature of 160 °C and a hydrogen atmosphere. The rest is the same as Example 1.
[0046] In this embodiment, the conversion rate of levulinic acid was 26.1%, and the selectivity of γ-valerolactone was 100%.
[0047] Example 4: The difference between this example and Example 1 is that the reaction was carried out under magnetic stirring for 3.0 h at a pressure of 1.2 MPa, a temperature of 160 °C and a hydrogen atmosphere. The rest is the same as Example 1.
[0048] In this embodiment, the conversion rate of levulinic acid was 65.9%, and the selectivity of γ-valerolactone was 100%.
[0049] Example 5: The difference between this example and Example 1 is that the reaction was carried out under magnetic stirring for 3.0 h at a pressure of 1.4 MPa, a temperature of 160 °C and a hydrogen atmosphere. The rest is the same as Example 1.
[0050] In this embodiment, the conversion rate of levulinic acid was 94.7%, and the selectivity of γ-valerolactone was 100%.
[0051] Example 6: The difference between this example and Example 1 is that the reaction was carried out under magnetic stirring for 3.0 h at a pressure of 1.6 MPa, a temperature of 160 °C and a hydrogen atmosphere. The rest is the same as Example 1.
[0052] In this embodiment, the conversion rate of levulinic acid was 100%, and the selectivity of γ-valerolactone was 100%.
[0053] Example 7: The difference between this example and Example 1 is that the reaction was carried out under magnetic stirring for 0.5 h at a pressure of 1.5 MPa, a temperature of 160 °C and a hydrogen atmosphere. The rest is the same as in Example 1.
[0054] In this embodiment, the conversion rate of levulinic acid was 5.7%, and the selectivity of γ-valerolactone was 100%.
[0055] Example 8: The difference between this example and Example 1 is that the reaction was carried out under magnetic stirring for 1.0 h at a pressure of 1.5 MPa, a temperature of 160 °C and a hydrogen atmosphere. The rest is the same as Example 1.
[0056] In this embodiment, the conversion rate of levulinic acid was 33.4%, and the selectivity of γ-valerolactone was 100%.
[0057] Example 9: The difference between this example and Example 1 is that the reaction was carried out under magnetic stirring for 2.0 h at a pressure of 1.5 MPa, a temperature of 160 °C and a hydrogen atmosphere. The rest is the same as Example 1.
[0058] In this embodiment, the conversion rate of levulinic acid was 96.2%, and the selectivity of γ-valerolactone was 100%.
[0059] Example 10: The difference between this example and Example 1 is that the reaction was carried out under magnetic stirring for 3.0 h at a pressure of 1.5 MPa, a temperature of 160 °C and a hydrogen atmosphere. The rest is the same as Example 1.
[0060] In this embodiment, the conversion rate of levulinic acid was 6.8%, and the selectivity of γ-valerolactone was 100%.
[0061] Example 11: This example differs from Example 1 in that the reaction was carried out under magnetic stirring for 3.0 h at a pressure of 1.5 MPa, a temperature of 140 °C, and a hydrogen atmosphere. Everything else is the same as in Example 1.
[0062] In this embodiment, the conversion rate of levulinic acid was 55.9%, and the selectivity of γ-valerolactone was 100%.
[0063] Example 12: This example differs from Example 1 in that the reaction was carried out under magnetic stirring for 3.0 h at a pressure of 1.5 MPa, a temperature of 150 °C, and a hydrogen atmosphere. Everything else is the same as in Example 1.
[0064] In this embodiment, the conversion rate of levulinic acid was 80.7%, and the selectivity of γ-valerolactone was 100%.
[0065] Example 13: The difference between this example and Example 1 is that the amount of catalyst used is 50 mg, and everything else is the same as in Example 1.
[0066] In this embodiment, the conversion rate of levulinic acid was 60.2%, and the selectivity of γ-valerolactone was 100%.
[0067] Example 14: The difference between this example and Example 1 is that the amount of catalyst used is 75 mg, and everything else is the same as in Example 1.
[0068] In this embodiment, the conversion rate of levulinic acid was 87.2%, and the selectivity of γ-valerolactone was 100%.
[0069] Example 15: The difference between this example and Example 1 is that the molybdenum selenide catalyst B is prepared according to the following steps:
[0070] (1) Place 0.62g of ammonium molybdate and 0.55g of selenium powder in 75mL of deionized water, add ethylenediamine dropwise (molar ratio of ammonium molybdate to ethylenediamine is 1:3), and then transfer to a hydrothermal reactor; (2) Heat the sealed hydrothermal crystallization reactor to 220℃, maintain for 48h, cool to room temperature, filter, wash, and dry to obtain molybdenum selenide catalyst B.
[0071] The molybdenum selenide catalyst B prepared in this embodiment was characterized by XRD. Figure 3 The results showed that all characteristic diffraction peaks of catalyst B were consistent with the MoSe2 standard card, indicating that the sample was pure-phase molybdenum selenide; its SEM image ( Figure 4 The image shows that the catalyst B sample prepared in this embodiment has a plate-like morphology.
[0072] Everything else is the same as in Example 1. In this example, the conversion rate of levulinic acid is 63.6%, and the selectivity of γ-valerol is 100%.
[0073] Example 16: The difference between this example and Example 1 is that the catalyst used is molybdenum selenide catalyst C, which is obtained by heating a sealed hydrothermal crystallization vessel to 220°C, maintaining it for 24 hours, cooling it to room temperature, filtering, washing, and drying. Everything else is the same as in Example 1.
[0074] In this embodiment, the conversion rate of levulinic acid was 89.8%, and the selectivity of γ-valerolactone was 100%.
[0075] Example 17: The difference between this example and Example 1 is that the catalyst used is molybdenum selenide catalyst D, which is obtained by heating a sealed hydrothermal crystallization vessel to 220°C, maintaining it for 36 hours, cooling it to room temperature, filtering, washing, and drying. Everything else is the same as in Example 1.
[0076] In this embodiment, the conversion rate of levulinic acid was 94.7%, and the selectivity of γ-valerolactone was 100%.
[0077] Example 18: The difference between this example and Example 1 is that the catalyst used is molybdenum selenide catalyst E, which is obtained by heating a sealed hydrothermal crystallization vessel to 220°C, maintaining it for 60 hours, cooling it to room temperature, filtering, washing, and drying. Everything else is the same as in Example 1.
[0078] In this embodiment, the conversion rate of levulinic acid was 100%, and the selectivity of γ-valerolactone was 100%.
[0079] Table 1 summarizes the conversion rates of levulinic acid and the selectivity of γ-valerol in Examples 1 to 18.
[0080] Table 1. Results of the reaction for the conversion of levulinic acid to γ-valerol.
[0081]
[0082] Continued from Table 1
[0083] .
Claims
1. A method for preparing γ-valerate by hydrogenation of levulinic acid catalyzed by molybdenum selenide, characterized in that... The method for preparing γ-valerol by hydrogenation of levulinic acid catalyzed by molybdenum selenide is implemented according to the following steps: Molybdenum selenide catalyst, levulinic acid and solvent were placed in a high-pressure reactor as raw materials. The air in the high-pressure reactor was first replaced with hydrogen gas several times at room temperature. Then, hydrogen gas was continued to be introduced until the pressure in the high-pressure reactor reached 1.5 MPa. The reaction was carried out under magnetic stirring at 160℃ and hydrogen atmosphere for 3.0 h. Then, the reaction was cooled to room temperature and the molybdenum selenide catalyst was separated to obtain γ-valerolactone. The preparation method of the molybdenum selenide catalyst is as follows: a. Place 0.62 g of ammonium molybdate and 0.55 g of selenium powder in 75 mL of deionized water, and add sodium borohydride solution dropwise. The molar ratio of ammonium molybdate to sodium borohydride is 1:
3. Then transfer the solution to a hydrothermal reactor. b. The sealed hydrothermal crystallization vessel is heated to 220°C and maintained for 48 h. After cooling to room temperature, the molybdenum selenide catalyst is obtained by filtration, washing and drying.
2. The method for preparing γ-valerate by hydrogenation of levulinic acid catalyzed by molybdenum selenide according to claim 1, characterized in that... The molybdenum selenide catalyst accounts for 0.5-4.0% of the mass fraction of the raw material.
3. The method for preparing γ-valerate by hydrogenation of levulinic acid catalyzed by molybdenum selenide according to claim 1, characterized in that... The solvent is water.
4. The method for preparing γ-valerate by hydrogenation of levulinic acid catalyzed by molybdenum selenide according to claim 1, characterized in that... The volume ratio of levulinic acid to solvent is 1:5~8.