Application of bismuth sulfide in preparation of gamma-valerolactone by catalytic hydrogenation of levulinic acid

Abstract

The application relates to application of bismuth sulfide in preparation of gamma-valerolactone through catalytic hydrogenation of leucic acid, in particular to a method for preparing gamma-valerolactone through photocatalytic hydrogenation of leucic acid by using bismuth sulfide, wherein isopropyl alcohol is used as a hydrogen donor and a solvent, bismuth sulfide non-noble metal photocatalyst synthesized by a solvent thermal method is used, and a low-pressure mercury lamp is used to efficiently catalyze leucic acid to prepare gamma-valerolactone under an argon atmosphere and at room temperature. The application efficiently completes the conversion from leucic acid to gamma-valerolactone under illumination, and the yield of gamma-valerolactone can reach 59% at most after 37 hours of reaction. The application has the characteristics of mild conditions, clean and non-polluted reaction process, low price and environmental friendliness.

Description

TECHNICAL FIELD

[0001] The application relates to an application of bismuth sulfide in preparation of gamma-valerolactone through catalytic hydrogenation of leucic acid, in particular to a method for preparing gamma-valerolactone through photocatalytic hydrogenation of leucic acid by using bismuth sulfide, and the method is used for preparing gamma-valerolactone through hydrogenation and cyclization of leucic acid under light conditions. BACKGROUND

[0002] Gamma-valerolactone can be used as a food additive and a green solvent, and is also an intermediate for synthesizing many organic compounds, and has wide application in the industry. Leucic acid, an upstream product of the gamma-valerolactone, is one of the top ten most promising biomass platform molecules, and can be obtained from cellulose and hemicellulose, and has wide sources and high yield.

[0003] Chinese patent CN104496945A discloses a method for preparing gamma-valerolactone through hydrogenation and cyclization of leucic acid. In the method, titanium dioxide is added into a leucic acid isopropanol reaction solution, a noble metal source solution is added at the same time, vacuum is extracted or argon is introduced under magnetic stirring, an ultraviolet light source is turned on, the noble metal source is reduced into noble metal particles in situ through photocatalysis, the noble metal particles are loaded on the surface of the titanium dioxide, and the photocatalysis of the leucic acid hydrogenation and cyclization to prepare gamma-valerolactone is started. The reaction temperature is controlled to be 15-60 DEG C, and the reaction time is controlled to be 10-36 hours. After the reaction is completed, the catalyst is separated through centrifugal precipitation, vacuum filtration or static precipitation, then isopropanol is removed through reduced pressure distillation, and the gamma-valerolactone is obtained.

[0004] CN111036239A discloses a novel sulfide catalyst, a preparation method and a method for synthesizing gamma-valerolactone. In particular, the application discloses a method for synthesizing gamma-valerolactone by using a supported sulfide catalyst. Specifically, the application discloses a preparation method of a supported catalyst taking molybdenum disulfide as a main active component and taking nickel, cobalt and copper as second metals, and application of the catalyst prepared by using the method in synthesis of gamma-valerolactone (GVL) from leucic acid and esters thereof.

[0005] Currently, most studies on the conversion of levulinic acid to γ-valerolactone use thermocatalysis, which is not mild enough due to its high temperature and high pressure conditions, and the use of heat energy also causes environmental pollution. In contrast, some studies have reported the use of photocatalysis to complete this reaction, but the use of precious metals such as platinum and gold increases the preparation cost, and the addition of strong bases increases the separation difficulty and is not environmentally friendly (References: ZHANG H, ZHAO M, ZHAO T, et al. Hydrogenative cyclization of levulinic acid into γ-valerolactone by photocatalytic intermolecular hydrogen transfer. Green Chemistry, 2016, 18(8): 2296-301; BUNRIT A, BUTBUREE T, LIU M, et al. Photo–Thermo-Dual Catalysis of LevulinicAcid and Levulinate Ester to γ-Valerolactone. ACS Catalysis, 2022, 12(3):1677-85.).

[0006] Current technologies often use supported noble metals and transition metals as active catalysts to achieve the hydrogenation cyclization of levulinic acid to prepare γ-valerol, and employ auxiliary reagents. However, these methods suffer from drawbacks such as demanding reaction conditions, complex operation processes, high production costs, and low levulinic acid conversion rates. Therefore, developing efficient non-noble metal photocatalysts to improve levulinic acid conversion and γ-valerol selectivity has become an urgent problem to be solved. Summary of the Invention

[0007] The purpose of this invention is to provide an application of bismuth sulfide in the catalytic hydrogenation of levulinic acid to prepare γ-valerolactone. It is an improvement on the method of photocatalytic hydrogenation of levulinic acid to prepare γ-valerolactone. By using bismuth sulfide as a photocatalyst, the conversion of levulinic acid to γ-valerolactone can be completed under mild, clean and efficient conditions under light and room temperature.

[0008] Isopropanol can serve as a hydrogen donor in catalytic transfer hydrogenation reactions, i.e., as a hydrogen source, and has the advantages of low cost, good selectivity, and mild reaction conditions. This invention utilizes isopropanol as both a hydrogen donor and solvent to synthesize a bismuth sulfide non-precious metal photocatalyst via a solvothermal method. This photocatalyst efficiently catalyzes the preparation of γ-valerol from levulinic acid under an argon atmosphere and at room temperature using a low-pressure mercury lamp.

[0009] This invention provides an application of bismuth sulfide in the catalytic hydrogenation of levulinic acid to prepare γ-valerol. The application method includes the following steps:

[0010] 1) The bismuth sulfide catalyst, the substrate levulinic acid, and the hydrogen-donating precursor isopropanol were added separately to a sealed quartz test tube reactor;

[0011] 2) Evacuate the air and introduce argon gas three times to ensure the reaction solution is in an argon atmosphere;

[0012] 3) Place the quartz test tube on a magnetic stirrer and irradiate it with a 30-100W low-pressure mercury lamp at room temperature for 30-40 hours to carry out the reaction;

[0013] 4) Filter the reaction solution and use gas chromatography to determine the conversion rate of levulinic acid and the yield of γ-valerol.

[0014] The present invention provides an application of bismuth sulfide in the catalytic hydrogenation of levulinic acid to prepare γ-valerol, wherein the bismuth sulfide catalyst in step 1) is synthesized by a solvothermal method.

[0015] Step 1) The mass of the bismuth sulfide catalyst is 40% of the substrate levulinic acid.

[0016] The low-pressure mercury lamp mentioned in step 3) preferably has a power of 30W and an irradiation time of 37h.

[0017] The method for preparing a bismuth sulfide catalyst provided by this invention is selected from:

[0018] 1) Add 2 mmol of bismuth nitrate pentahydrate to 35 mL of deionized water, stir thoroughly for 20-30 min, then add 30 mmol of thiourea. Transfer the reaction solution to a 50 mL polytetrafluoroethylene-lined reactor and maintain it in an oven at 150-200℃ for 15-18 h. After the reactor cools, separate the bismuth sulfide product from the reaction solution, wash it three times alternately with water and ethanol, and finally dry it in a vacuum oven at 50℃ for 12 h. Grind it into powder; or

[0019] 2) Add 0.6 mmol of bismuth nitrate pentahydrate to 40 mL of ethylene glycol, stir thoroughly for 20-30 min, then add 6 mmol of thiourea and stir for another 20-30 min. Transfer the reaction solution to a 50 mL polytetrafluoroethylene-lined reactor and maintain it in an oven at 150-180℃ for 20-24 h. After the reactor cools, separate the bismuth sulfide product from the reaction solution, wash it three times alternately with water and ethanol, and finally dry it in a vacuum oven at 50℃ for 12 h. Grind it into powder; or

[0020] 3) Add 1.5 mmol of bismuth nitrate pentahydrate to 5 mL of glycerol and stir for 20-30 min to obtain solution A; add 6 mmol of sodium sulfide nonahydrate to 10 mL of water and stir for 20-30 min to obtain solution B; then mix solutions A and B, stir for 20-30 min, add 15 mL of 0.85 mol / L urea solution, stir evenly, transfer the mixed solution to a 50 mL polytetrafluoroethylene reactor liner, keep in an oven at 100-120℃ for 10-12 h, cool, and finally separate the reaction product bismuth sulfide, wash three times alternately with water and ethanol, and finally dry in a vacuum oven at 50℃ for 12 h and grind into powder.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. This invention utilizes a synthesized bismuth sulfide catalyst to efficiently convert levulinic acid to γ-valerolactone under light irradiation, with the yield of γ-valerolactone reaching up to 59% after 37 hours of reaction.

[0023] 2. This invention uses isopropanol as a hydrogen donor and solvent, with mild conditions and a clean and pollution-free reaction process.

[0024] 3. The catalyst used in this invention is a non-precious metal catalyst, which is inexpensive and environmentally friendly. Attached Figure Description

[0025] Figure 1 The images show SEM images of the catalyst materials BS-1 (a), BS-2 (b), and BS-3 (c) in the examples. Detailed Implementation

[0026] The following is a further description of the invention, but not a limitation thereof.

[0027] Experimental methods and tests not specifically described in the examples are generally performed under conventional conditions and as described in the manual, or as recommended by the manufacturer; the general equipment, materials, reagents, etc. used are commercially available unless otherwise specified.

[0028] The bismuth sulfide catalyst described in this invention is synthesized using a solvothermal method. For details, please refer to the following literature:

[0029] 1) T. Thai Ha Vu, T. Anh Thu Do, Duc Toan Nguyen, et al. Facile one-step growth of hierarchical Bi2S3@MoS2 structures for enhanced photocatalytic activity, Materials Today Communications, 2022 (31) 103541.

[0030] 2) Ke Yan, Donghai Wu, Ting Wang, et al. ACS Catalysis, 2023 (13)2302-2312.

[0031] 3) Weili Dai, Junjie Yu, Shenglian Luo, et al. WS2 quantum dotsseeding in Bi2S3 nanotubes: A novel Vis-NIR light sensitive photocatalyst with low-resistance junction interface for CO2 reduction, Chemical EngineeringJournal, 2020 (389) 123430.

[0032] Example 1

[0033] Add 2 mmol of bismuth nitrate pentahydrate to 35 mL of deionized water and stir for 30 min. Then add 30 mmol of thiourea and stir for another 30 min. Transfer the solution to a 50 mL polytetrafluoroethylene reactor liner and keep it in a 200 °C oven for 18 h. After the reactor cools down, wash the bismuth sulfide material in the reaction solution three times each with water and ethanol. Then place it in a 50 °C vacuum oven (90 kPa vacuum) to dry for 12 h. Grind the dried catalyst into powder and designate it as BS-1.

[0034] Add 200 mg of levulinic acid, 50 mg of BS-1 catalyst, and 10 mL of isopropanol sequentially to a 50 mL quartz tube. Seal the tube and evacuate and then introduce argon gas three times. Finally, the reaction solution is in an argon atmosphere. Place the quartz tube on a magnetic stirrer and use a 30 W low-pressure mercury lamp (220 V 30 W, Guangzhou Xingchuang Electronics Co., Ltd., XC230803) for a reaction of 37 h. After the reaction is completed, filter the reaction solution using a 0.22 μm organic filter membrane.

[0035] Assay method: 0.1 mL of 1000 ppm dodecane (internal standard) in isopropanol solution was added to 0.7 mL of filtered reaction solution to prepare the test solution. The content of substrate and product in the test solution was determined by gas chromatography using the internal standard method. The gas chromatography analysis conditions were: FID detector, injection port temperature 250℃, column temperature 140℃, detector temperature 260℃, injection volume 1 μL, and detection time 21 min. Finally, the conversion rate of levulinic acid and the yield of γ-valerolactone in the reaction were calculated by calculating the area ratio of substrate and product to the internal standard dodecane and comparing with the standard curve. The results are listed in Table 1.

[0036] Example 2

[0037] Add 0.6 mmol of bismuth nitrate pentahydrate to 40 mL of ethylene glycol and stir for 30 min. Then add 6 mmol of thiourea and stir for another 30 min. Transfer the solution to a 50 mL polytetrafluoroethylene reactor liner and keep it in an oven at 180 °C for 24 h. After the reactor cools down, wash the bismuth sulfide material in the reaction solution three times each with water and ethanol. Then place it in a vacuum oven at 50 °C (vacuum degree 90 kPa) to dry for 12 h. Grind the dried catalyst into powder and designate it as BS-2.

[0038] 200 mg of levulinic acid, 50 mg of BS-2 catalyst, and 10 mL of isopropanol were added sequentially to a 50 mL quartz tube. The tube was sealed, and the mixture was evacuated and then purged with argon gas three times. The final reaction solution was in an argon atmosphere. The quartz tube was placed on a magnetic stirrer and reacted for 37 h using a 30 W low-pressure mercury lamp (220 V 30 W, Guangzhou Xingchuang Electronics Co., Ltd., XC230803). After filtration, the conversion rate of levulinic acid and the yield of γ-valerol were determined by gas chromatography. The post-processing and determination methods were the same as in Example 1. The results are listed in Table 1.

[0039] Example 3

[0040] Add 1.5 mmol of bismuth nitrate pentahydrate to 5 mL of glycerol and stir for 30 min, denoted as solution A; add 6 mmol of sodium sulfide nonahydrate to 10 mL of deionized water and stir for 30 min, denoted as solution B; mix solutions A and B and stir for 30 min, then add 15 mL of 0.85 mol / L urea solution and stir for 30 min. Finally, transfer the solution to a 50 mL polytetrafluoroethylene reactor liner and keep it in an oven at 180 °C for 24 h. After the reactor cools down, wash the bismuth sulfide material in the reaction solution three times each with water and ethanol, and then place it in a vacuum oven at 50 °C (vacuum degree 90 kPa) to dry for 12 h. Grind the dried catalyst into powder, denoted as BS-3.

[0041] 200 mg of levulinic acid, 50 mg of BS-3 catalyst, and 10 mL of isopropanol were added sequentially to a 50 mL quartz tube. The tube was sealed, and the reaction was evacuated and purged with argon gas three times. The final reaction solution was in an argon atmosphere. The quartz tube was placed on a magnetic stirrer and reacted for 37 h using a 30 W low-pressure mercury lamp (220 V 30 W, Guangzhou Xingchuang Electronics Co., Ltd., XC230803). After filtration, the conversion rate of levulinic acid and the yield of γ-valerol were determined by gas chromatography. The post-processing and determination methods were the same as in Example 1. The results are listed in Table 1.

[0042] In currently reported studies, Chinese patent CN104496945A uses modified TiO2-P25 (RA-TiO2) as a catalyst and isopropanol as a solvent, achieving a yield of 67% after 9 hours of reaction. CN111036239A discloses a novel sulfide catalyst and its preparation method, as well as a method for synthesizing γ-valerolactone. A supported catalyst using molybdenum disulfide as the main active component and nickel, cobalt, copper, or other metals as secondary metals is used in a thermocatalytic method to convert levulinic acid and its esters to γ-valerolactone under high temperature and high pressure conditions, achieving a γ-valerolactone yield of 85.7%. Some literature uses commercial niobic acid as a catalyst, achieving a conversion rate of 30% and a selectivity of 45% after 24 hours of reaction under 11W low-pressure mercury lamp irradiation (Reference: FILHO JBG, RIOS RDF, BRUZIQUESI CGO, et al. A promising approach to transform levulinic acid into γ-valerolactone using niobic acid photocatalyst and theaccumulated electron transfer technique. Applied Catalysis B: Environmental, 2021, 285: 119814.).

[0043] Compared to the above studies, this invention does not use precious metal catalysts and strong bases in the reaction process, is low in cost and environmentally friendly, and achieves 97% selectivity and 59% product yield cleanly and efficiently when using non-precious metal catalysts.

[0044] Table 1 shows the detection results in each embodiment.

[0045] Examples Catalyst Levulinic acid conversion (%) Gamma-valerolactone yield (%) 1 BS-1 97.0 59.3 2 BS-2 90.4 51.3 3 BS-3 95.1 41.2

Claims

1. Use of bismuth sulfide in the catalytic hydrogenation of levulinic acid to produce gamma-valerolactone, the method comprising the steps of: 1) adding bismuth sulfide catalyst, substrate levulinic acid and hydrogen donor precursor isopropyl alcohol into a sealed quartz test tube reactor, respectively; 2) vacuumizing and purging with argon three times, respectively, to make the reaction solution in an argon atmosphere; 3) placing the quartz test tube on a magnetic stirrer, irradiating with a 30-100 W low-pressure mercury lamp at room temperature for 30-40 h to carry out the reaction; 4) filtering the reaction solution and determining the conversion rate of levulinic acid and the yield of gamma-valerolactone by gas chromatography.

2. Use according to claim 1, characterized in that The bismuth sulfide catalyst in step 1) is synthesized by a solvothermal method.

3. Use according to claim 1, characterized in that The mass of the bismuth sulfide catalyst in step 1) is 40% of the substrate levulinic acid.

4. Use according to claim 1, characterized in that The power of the low-pressure mercury lamp in step 3) is 30 W, and the irradiation time is 37 h.

5. The use according to claim 1, characterized in that The preparation method of the bismuth sulfide catalyst is selected from: 1) adding 2 mmol of bismuth nitrate pentahydrate into 35 mL of deionized water, stirring thoroughly for 20-30 min, then adding 30 mmol of thiourea, transferring the reaction solution into a 50 mL polytetrafluoroethylene-lined reaction kettle, keeping in an oven at 150-200 ℃ for 15-18 h, separating the product bismuth sulfide from the reaction solution after the reaction kettle is cooled, washing with water and ethanol alternately for three times, and finally drying in a vacuum oven at 50 ℃ for 12 h and grinding into powder; or 2) adding 0.6 mmol of bismuth nitrate pentahydrate into 40 mL of ethylene glycol, stirring thoroughly for 20-30 min, then adding 6 mmol of thiourea, stirring for 20-30 min; transferring the reaction solution into a 50 mL polytetrafluoroethylene-lined reaction kettle, keeping in an oven at 150-180 ℃ for 20-24 h, separating the product bismuth sulfide from the reaction solution after the reaction kettle is cooled, washing with water and ethanol alternately for three times, and finally drying in a vacuum oven at 50 ℃ for 12 h and grinding into powder; or 3) adding 1.5 mmol of bismuth nitrate pentahydrate into 5 mL of glycerol, stirring for 20-30 min to obtain solution A; adding 6 mmol of sodium sulfide nonahydrate into 10 mL of water, stirring for 20-30 min to obtain solution B; then mixing solutions A and B, stirring for 20-30 min, adding 15 mL of 0.85 mol / L urea solution, stirring uniformly, transferring the mixed solution into a 50 mL polytetrafluoroethylene-lined reaction kettle, keeping in an oven at 100-120 ℃ for 10-12 h, cooling, finally separating the reaction product bismuth sulfide, washing with water and ethanol alternately for three times, and finally drying in a vacuum oven at 50 ℃ for 12 h and grinding into powder.

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