Vanadium-containing molecular sieve catalyst for preparing acetyl n-propanol through catalytic oxidation of 2-methyltetrahydrofuran and preparation method of vanadium-containing molecular sieve catalyst
By using a vanadium-containing molecular sieve catalyst to oxidize 2-methyltetrahydrofuran with molecular oxygen to prepare acetylacetonol, the high cost and environmental pollution problems caused by precious metal catalysts have been solved, and a new, efficient and environmentally friendly process route has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-05-01
AI Technical Summary
Existing processes for preparing acetylacetonol use precious metal catalysts, resulting in high costs and generating large amounts of acidic wastewater, making it difficult to replace traditional production processes.
By using vanadium-containing molecular sieve catalysts and molecular oxygen as the oxidant, and by controlling the ion exchange conditions and calcination temperature, a highly active and selective catalyst was prepared to replace the precious metal catalyst.
It significantly reduces catalyst costs, minimizes environmental pollution, improves atom economy and catalytic activity, exhibits strong adaptability, and has promising prospects for industrial applications.
Smart Images
Figure CN121945152A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of vanadium-containing molecular sieve catalyst preparation and catalytic oxidation of 2-methyltetrahydrofuran, specifically to a vanadium-containing molecular sieve catalyst and preparation method for catalytic oxidation of 2-methyltetrahydrofuran to acetyl-n-propanol. Background Technology
[0002] Acetylacetonol is mainly used as a raw material in organic synthesis and a pharmaceutical intermediate, and can be used in the production of chloroquine phosphate and vitamin B1. The production methods of acetylacetonol include the condensation-decarboxylation of γ-butyrolactone and acetate or the hydrogenation hydrolysis of 2-methylfuran (as shown below). Traditional reaction routes are long, have low atom utilization, and require harsh reaction conditions. The 2-methylfuran hydrogenation hydrolysis route uses precious metal catalysts, requires a long reaction time, and generates large amounts of low-concentration waste acid and wastewater, resulting in high production costs, low efficiency, and significant environmental challenges. Therefore, there is an urgent need to develop new reaction routes for the biomass-based production of acetylacetonol that do not rely on precious metal catalysts.
[0003]
[0004] Using heteropoly acid Na4H3[SiW9Al3(H2O)3O 37 Using 12H2O (SiW9Al3) as a catalyst and 30 wt% H2O2 as an oxidant, 1,4-pentanediol was oxidized. When 1,4-pentanediol was completely converted, the yield of the target product reached 62% (as shown below).
[0005]
[0006] 3-AP can be synthesized by hydration reaction using 4-pentyn-1-ol and 3-pentyn-1-ol as substrates in the presence of a Pt complex catalyst (as shown below).
[0007]
[0008] The above reaction route still has shortcomings such as low product yield, difficulty in using precious metal catalysts or separating reaction products, resulting in high production costs and making it difficult to replace existing traditional production processes.
[0009] 2-Methyltetrahydrofuran is a biomass-derived chemical, primarily used as a solvent and intermediate in chemical reactions. It can be prepared from furfural, a readily available biomass platform compound. Furfural is hydrogenated over a copper-based catalyst to produce 2-methylfuran at 190°C, with a product yield ≥98%. Further hydrogenation of 2-methylfuran under Raney nickel catalysis at 150°C yields 2-methyltetrahydrofuran (product yield >90%). Using readily available 2-methyltetrahydrofuran as a starting material and molecular oxygen as the oxidant, a novel reaction route is proposed to oxidize and produce the target product, acetylacetonol (as shown below). This route does not use precious metal catalysts; therefore, the core challenge in achieving this design is the preparation of highly active and selective catalysts.
[0010] Summary of the Invention
[0011] To address the high cost of existing processes for preparing acetylacetonate-n-propanol due to the use of precious metal catalysts, this invention provides a vanadium-containing molecular sieve catalyst and its preparation method for the catalytic oxidation of 2-methyltetrahydrofuran to acetylacetonate-n-propanol. The catalyst prepared by this invention is a catalyst for the catalytic oxidation of 2-methyltetrahydrofuran to acetylacetonate-n-propanol using molecular oxygen, realizing a new route for the preparation of acetylacetonate-n-propanol.
[0012] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0013] A method for preparing a vanadium-containing molecular sieve catalyst for the catalytic oxidation of 2-methyltetrahydrofuran to acetylpropanol is disclosed. The method specifically involves using a sodium silicate alumina type microporous molecular sieve as a precursor, performing ion exchange with an aqueous solution of a vanadium-containing compound, followed by washing, drying, and calcination to obtain the vanadium-containing molecular sieve catalyst.
[0014] As a preferred embodiment of the present invention, the sodium silicate-aluminate microporous molecular sieve is: Na-Y, Na-Beta, Na-ZSM-5, or Na-MOR.
[0015] As a preferred embodiment of the present invention, the nSi / nAl ratio of the sodium silicate-aluminate microporous molecular sieve is 1-20.
[0016] As a preferred embodiment of the present invention, the vanadium-containing compound includes, but is not limited to, one of: vanadium oxysulfate, vanadium dichloride, and VO(acac)2.
[0017] As a preferred embodiment of the present invention, the ion exchange temperature is 20-80℃ and the exchange time is 1-8 h.
[0018] As a preferred embodiment of the present invention, the drying temperature is 60-120℃.
[0019] As a preferred embodiment of the present invention, the calcination temperature is 450~600℃ and the calcination time is 3~8 h.
[0020] As a preferred embodiment of the present invention, the molar ratio of sodium ions to Brønsted acid sites in the vanadium-containing molecular sieve catalyst is 0.1 to 80.
[0021] Sodium content was determined by inductively coupled plasma atomic emission spectrometry, and Brønsted acid content was determined by pyridine adsorption infrared spectroscopy at 1540 cm⁻¹. -1 The absorption peak area at that location was calculated.
[0022] As a preferred embodiment of the present invention, the vanadium content of the vanadium-containing catalyst is 0.1~5 wt%.
[0023] As a preferred embodiment of the present invention, the vanadium-containing molecular sieve catalyst prepared by the preparation method is used for the catalytic oxidation of 2-methyltetrahydrofuran to prepare acetylacetonol.
[0024] As a preferred embodiment of the present invention, the mass ratio of the catalyst used in the catalytic reaction to the volume ratio of the reactant 2-methyltetrahydrofuran is 0.01 g·mL. -1 The pressure of O2 is 1.5 MPa.
[0025] As a preferred embodiment of the present invention, the temperature of the catalytic reaction is 50-120℃, and the reaction time is 3 h.
[0026] As a preferred embodiment of the present invention, acetonitrile solvent is added to the reactant 2-methyltetrahydrofuran during the catalytic reaction, and the volume ratio of 2-methyltetrahydrofuran to acetonitrile solvent is 1:10.
[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0028] 1. The catalyst prepared by this invention does not contain any precious metals (such as Pd, Ru, etc.). This invention uses a non-precious metal vanadium-containing molecular sieve catalyst to replace the precious metal or rare metal catalysts such as Pt, Raney Ni in traditional processes, which significantly reduces the cost of catalyst raw materials and avoids the impact of precious metal resource scarcity and price fluctuations on production costs.
[0029] 2. This invention uses molecular oxygen (O2) as an oxidant, and the main reaction byproduct is water. It has high atom economy and is environmentally friendly. The reaction process does not produce a large amount of acidic wastewater or corrosive waste liquid, which reduces the burden of subsequent environmental protection treatment and is in line with the development direction of green chemistry.
[0030] 3. This invention, by adjusting parameters such as ion exchange conditions (e.g., temperature, time, vanadium source type), calcination temperature, and molecular sieve type, can achieve high dispersion and valence state control of vanadium species in molecular sieves (e.g., V2). 4+ / V5+ (Proportion), thereby improving catalytic activity and selectivity of acetyl-n-propanol.
[0031] 4. The raw material 2-methyltetrahydrofuran used in this invention is widely available and can be obtained from the biomass platform compound furfural through two-step hydrogenation. The raw material is renewable. The catalyst preparation method is simple and the catalytic reaction conditions are mild (temperature 50-120℃, pressure 1.5 MPa), which has good process adaptability and scale-up potential.
[0032] 5. The catalyst prepared by this invention maintains high catalytic activity and product yield even after being used 6 times consecutively, indicating that it has a stable structure, long lifespan, and good prospects for industrial application. Attached Figure Description
[0033] Figure 1 Na-Y, VO x XRD and XPS plots of Na-Y, (a) XRD, (b) XPS plot.
[0034] Figure 2 VO in Example 15 x -Na-Y is the result of catalytic oxidation of 2-methyltetrahydrofuran. Detailed Implementation
[0035] The technical solution and effects of the present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.
[0036] Example 1
[0037] The catalyst preparation process in this embodiment is as follows:
[0038] VOSO4 was dissolved in deionized water (theoretical vanadium content is 1.0 wt%, based on the theoretical final catalyst mass). Na-Y molecular sieve (nSi / nAl = 3.2) was added to the VOSO4 aqueous solution, and the mixture was impregnated at 30℃ for 2 h for ion exchange. After impregnation, the sample was washed three times with deionized water and then dried in an oven at 120℃. The dried sample was calcined in an air atmosphere at 550℃ for 8 h to obtain the catalyst. The vanadium content of the prepared sample was determined to be 0.46%.
[0039] XRD and XPS data of the samples are attached. Figure 1 ,Depend on Figure 1 It can be seen that vanadium is highly dispersed in the prepared sample, n(V 4+ ) / n(V 5+ =3.8.
[0040] The process of using the prepared catalyst to catalyze the oxidation of 2-methyltetrahydrofuran to acetylacetonol is as follows:
[0041] The prepared catalyst, 2-methyltetrahydrofuran, and acetonitrile solvent were sequentially added to a high-pressure reactor and sealed (V). 2-甲基四氢呋喃 V 乙腈 = 1 : 10, the mass ratio of catalyst to reactant is 0.01 g·mL -1 Next, O2 was introduced to 1.5 MPa, and the reaction was carried out at 100°C for 3 h.
[0042] The conversion rate of 2-methyltetrahydrofuran was 39.5%, and the yield of acetylacetonol was 20.3% (both yields were carbon yields).
[0043] Example 2
[0044] The dried solid sample obtained in Example 1 was calcined in a muffle furnace at 450°C for 8 h, and other preparation conditions were the same as in Example 1.
[0045] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 31.5% for 2-methyltetrahydrofuran and a yield of 18.0% for acetylacetonol.
[0046] Example 3
[0047] The dried solid sample obtained in Example 1 was calcined in a muffle furnace at 600°C for 8 h, and other preparation conditions were the same as in Example 1.
[0048] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 30.5% for 2-methyltetrahydrofuran and a yield of 16.6% for acetylacetonol.
[0049] Examples 2-3 show that excessively high calcination temperatures can lead to a decrease in catalyst performance.
[0050] Example 4
[0051] The concentration of VOSO4 was increased (theoretical vanadium content is 6.0 wt%, based on theoretical final product quality), and other preparation conditions were the same as in Example 1. The measured vanadium content of the prepared sample was 3.4%.
[0052] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 48.5% for 2-methyltetrahydrofuran and a yield of 23.9% for acetylacetonol.
[0053] Comparing Examples 1 and 4, it was found that increasing the vanadium content is beneficial to improving the performance of the catalyst.
[0054] Example 5
[0055] The impregnation temperature was changed to 60°C, and other preparation conditions were the same as in Example 1. The measured vanadium content of the prepared sample was 0.58%.
[0056] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 42.5% for 2-methyltetrahydrofuran and a yield of 24.8% for acetylacetonol.
[0057] Example 6
[0058] The impregnation time was extended to 8 hours, and other preparation conditions were the same as in Example 1. The measured vanadium content of the prepared sample was 0.52%.
[0059] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 41.6% for 2-methyltetrahydrofuran and a yield of 22.1% for acetylacetonol.
[0060] Example 7
[0061] A 1.0 mol / L ammonium chloride aqueous solution was used to perform two ion exchanges on the Na-Y molecular sieve at a solid (mass) to liquid (volume) ratio of 1:10 (g / mL) and a temperature of 60°C. The exchanged sample was dried and calcined at 500°C for 2 hours. The Na ion content after the treatment was measured to be 65% of the original content. This molecular sieve was used to replace Na-Y in Example 1, and other preparation conditions were the same.
[0062] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 52.6% for 2-methyltetrahydrofuran and a yield of 20.9% for acetylacetonol.
[0063] Example 8
[0064] Using VOCl2 as the vanadium source, and with other preparation conditions the same as in Example 1, the measured vanadium content of the prepared sample was 0.61%.
[0065] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 42.5% for 2-methyltetrahydrofuran and a yield of 23.5% for acetylacetonol.
[0066] Example 9
[0067] Using VO(acac)2 as the vanadium source, and with other preparation conditions the same as in Example 1, the measured vanadium content of the prepared sample was 0.56%.
[0068] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 39.5% for 2-methyltetrahydrofuran and a yield of 26.2% for acetylacetonol.
[0069] Example 10
[0070] Na-Beta molecular sieve (nSi / nAl = 15) was used instead of Na-Y in Example 1, and other preparation conditions were the same as in Example 1. The measured vanadium content of the prepared sample was 0.35%.
[0071] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 49.6% for 2-methyltetrahydrofuran and a yield of 15.3% for acetylacetonol.
[0072] Example 11
[0073] Na-MOR molecular sieve (nSi / nAl = 10) was used to replace Na-Y in Example 1, and other preparation conditions were the same as in Example 1. The measured vanadium content of the prepared sample was 0.35%.
[0074] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 56.9% for 2-methyltetrahydrofuran and a yield of 18.9% for acetylacetonol.
[0075] Example 12
[0076] Na-ZSM-5 molecular sieve (nSi / nAl = 20) was used to replace Na-Y in Example 1, and other preparation conditions were the same as in Example 1. The measured vanadium content of the prepared sample was 0.35%.
[0077] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 2-methyltetrahydrofuran of 23.9% and a yield of acetylacetonol of 10.9%.
[0078] Example 13
[0079] The impregnated sample was dried at 60°C using a rotary evaporator. Other steps were the same as in Example 1. The measured vanadium content of the prepared sample was 1.05%.
[0080] The catalytic reaction was carried out in the same manner as in Example 1, with a conversion of 43.5% for 2-methyltetrahydrofuran and a yield of 25.1% for acetylacetonol.
[0081] Example 14
[0082] The catalyst from Example 13 and 2-methyltetrahydrofuran were sequentially added to a high-pressure reactor and sealed (the mass ratio of the catalyst to the volume of 2-methyltetrahydrofuran was 0.01 g·mL). -1 Next, O2 was introduced to 1.5 MPa. The reaction was carried out at 80°C for 3 h.
[0083] The conversion rate of 2-methyltetrahydrofuran was 51%, and the yield of acetylacetonol was 20.1%.
[0084] Example 15
[0085] The catalyst from the reaction in Example 13 was centrifuged, dried, and used in the next reaction. This process was repeated six times, and the conversion rate of 2-methyltetrahydrofuran and the yield of acetylacetonol remained essentially unchanged. The results are as follows: Figure 2 As shown.
[0086] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a vanadium-containing molecular sieve catalyst for the catalytic oxidation of 2-methyltetrahydrofuran to acetylacetonol, characterized in that, The specific preparation method is as follows: using sodium silicate-alumina type microporous molecular sieve as a precursor, ion exchange is performed using an aqueous solution of vanadium-containing compound, followed by water washing, drying, and calcination to prepare a vanadium-containing molecular sieve catalyst.
2. The preparation method according to claim 1, characterized in that, The sodium silicate aluminum type microporous molecular sieve is: Na-Y, Na-Beta, Na-ZSM-5 or Na-MOR.
3. The preparation method according to claim 1, characterized in that, The vanadium-containing compounds include, but are not limited to, one of: vanadium oxysulfate, vanadium dichloride, and VO(acac)2.
4. The preparation method according to claim 1, characterized in that, The ion exchange temperature is 20-80℃, and the exchange time is 1-8 h.
5. The preparation method according to claim 1, characterized in that, The roasting temperature is 450~600℃, and the roasting time is 3~8 h.
6. The preparation method according to claim 1, characterized in that, The vanadium content of the vanadium-containing catalyst is 0.1~5 wt%.
7. The preparation method according to any one of claims 1 to 6, characterized in that, The vanadium-containing molecular sieve catalyst prepared by the method described above is used to catalyze the oxidation of 2-methyltetrahydrofuran to prepare acetylpropanol.
8. The preparation method according to claim 7, characterized in that, The mass ratio of the catalyst used in the catalytic reaction to the volume of the reactant 2-methyltetrahydrofuran was 0.01 g·mL. -1 The pressure of O2 is 1.5 MPa.
9. The preparation method according to claim 7, characterized in that, The temperature of the catalytic reaction is 50-120℃, and the reaction time is 3 h.
10. The preparation method according to claim 7, characterized in that, During the catalytic reaction, acetonitrile solvent is added to the reactant 2-methyltetrahydrofuran, with a volume ratio of 1:10 between 2-methyltetrahydrofuran and acetonitrile solvent.