Preparation method of cyclopentanol
The microwave-assisted preparation of zirconium-silicon hierarchical porous molecular sieve catalysts has solved the problems of high pollution and high cost in the oxidation of cyclopentane to cyclopentanol, and has achieved high selectivity and high yield of cyclopentanol production, which is in line with the goal of green chemical industry.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2026-04-24
AI Technical Summary
Existing processes for oxidizing cyclopentane to cyclopentanol suffer from high pollution and high cost, and traditional methods struggle to achieve high selectivity and high yield in the production of cyclopentanol.
A zirconium-silicon hierarchical porous molecular sieve catalyst was prepared by microwave-assisted method. Cyclopentane, oxidant and solvent were mixed with the catalyst in a closed reactor to carry out an oxidation reaction to generate cyclopentanol.
The process achieves highly selective conversion of cyclopentane to cyclopentanol, with a cyclopentanol yield exceeding 60% and a selectivity of 90.7%. The process is simple, produces little pollution, is low in cost, and meets the requirements of an environmentally friendly process.
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Figure CN121913872A_ABST
Abstract
Description
Technical Field
[0001] This application relates to a method for preparing cyclopentanol, belonging to the field of chemical engineering technology. Background Technology
[0002] Cyclopentane, an important product obtained from C5 fractions, has low market added value. Cyclopentanol, on the other hand, is an important intermediate in pharmaceutical and pesticide fine chemical products, mainly used in the production of drugs, fuels, and fragrances, and also as a solvent in drug and fragrance preparation processes. Therefore, producing high-value-added cyclopentanol from cyclopentane not only improves the effective utilization rate of cyclopentane but also aligns with the green and environmentally friendly goals of modern chemical industry.
[0003] Traditional cyclopentanol production routes can be divided into the adipic acid method and the cyclopentene method. The adipic acid method, however, uses expensive raw materials and generates significant pollutants, limiting its development. The cyclopentene method, on the other hand, has a long process route and pollutes the environment, contradicting the principles of green development. The cyclopentane method, however, directly produces cyclopentanol through hydrogen peroxide oxidation, with only water as a byproduct and no waste discharge. It also has low processing costs and is considered an environmentally friendly process. However, since the oxidation of cyclopentane to cyclopentanol can be further oxidized to cyclopentanone, as shown in patent CN116120157A, the highly selective conversion of cyclopentane to cyclopentanone has become a research hotspot. Summary of the Invention
[0004] In view of the problems existing in conventional technologies, the purpose of this invention is to provide a catalyst for the preparation and application of cyclopentanol. The catalyst has a wide pore size and large specific surface area, and the metal introduced into the molecular sieve framework plays a role in high dispersion and synergistic effect, exhibiting excellent catalytic performance in the oxidation of cyclopentane to cyclopentanol.
[0005] This invention provides a method for preparing a catalyst for generating cyclopentanol. The method involves introducing metallic zirconium into acid-washed H-HSZ molecular sieves using a microwave-assisted method to construct a zirconium-silicon hierarchical porous H-HSZ molecular sieve catalyst.
[0006] According to one aspect of this application, a method for preparing cyclopentanol is provided, the method comprising: In a closed reactor, a mixture containing a catalyst, solvent, oxidant, and cyclopentane is reacted to yield cyclopentanol. The catalyst is a zirconium-silicon hierarchical porous molecular sieve catalyst.
[0007] Optionally, the preparation method of the zirconium-silicon hierarchical porous molecular sieve catalyst includes the following steps: S1: The HSZ molecular sieve is crystallized, acid-treated (I), dried (I), and calcined (I) to obtain H-HSZ molecular sieve; S2: A mixture containing H-HSZ molecular sieve and zirconium salt is subjected to microwave-assisted digestion, acid treatment II, drying II, and calcination II to obtain a zirconium-silicon hierarchical porous molecular sieve catalyst.
[0008] Optionally, the mass of metallic zirconium in the zirconium-silicon hierarchical porous molecular sieve catalyst is 0.5-5%.
[0009] Optionally, the mass of metallic zirconium in the zirconium-silicon hierarchical porous molecular sieve catalyst is independently selected from any value of 0.5%, 1%, 2%, 3%, 4%, 5% or a range between any two of the above.
[0010] Optionally, the zirconium salt is selected from at least one of Zr(NO3)4·5H2O, ZrCl4, Zr(CH3COO)4·4H2O, and Zr(SO4)2·4H2O.
[0011] Optionally, in step S1, the crystallization rotation speed is 60~120 r / min, the crystallization temperature is 120~170℃, and the crystallization time is 12~72 h.
[0012] Optionally, in step S1, the crystallization rotation speed is independently selected from any value among 60 r / min, 70 r / min, 80 r / min, 90 r / min, 100 r / min, 110 r / min, and 120 r / min, or a range between any two of the above.
[0013] Optionally, in step S1, the crystallization temperature is independently selected from any value of 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, or a range between any two of the above.
[0014] Optionally, in step S1, the crystallization time is independently selected from any value of 12h, 24h, 36h, 48h, 60h, 72h or a range between any two of the above.
[0015] Optionally, the conditions for acid treatment I and acid treatment II are independently 1-3 mol / L nitric acid solution, and washing for 10-30 h.
[0016] Optionally, the temperature of drying I and drying II is independently selected from 90~130℃, and the time is independently selected from 6~12h.
[0017] Optionally, the temperature of calcination I and calcination II is independently selected from 500~600℃, and the time is independently selected from 6~10h.
[0018] Optionally, in step S2, the temperature of the microwave-assisted digestion is 60~90℃, and the time of the microwave-assisted digestion is 2~6h.
[0019] Optionally, in step S2, the temperature of the microwave-assisted digestion is independently selected from any value of 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃ or a range between any two of the above.
[0020] Optionally, in step S2, the microwave-assisted digestion time is independently selected from any value of 2h, 3h, 4h, 5h, 6h or a range between any two of the above.
[0021] Optionally, the mass ratio of cyclopentane to the catalyst is 1:10~50.
[0022] Optionally, the mass ratio of cyclopentane to solvent is 1:2 to 10.
[0023] Optionally, the mass ratio of cyclopentane to the oxidant is 1:0.5~5.
[0024] Optionally, the reaction temperature is 40~100℃ and the reaction time is 4~10 hours.
[0025] Optionally, the oxidant is hydrogen peroxide, and the concentration of the hydrogen peroxide is 15-50%.
[0026] Optionally, the solvent is selected from at least one of methanol, acetone, acetonitrile, and tert-amyl alcohol.
[0027] The beneficial effects that this application can produce include: 1) The method for preparing cyclopentanol provided in this application is a one-pot oxidation of cyclopentane to produce cyclopentanol, which has simple reaction steps, simple equipment route, and low investment.
[0028] 2) The method for preparing cyclopentanol provided in this application produces very little waste, only water, resulting in minimal pollution and extremely high environmental benefits. It is an environmentally friendly process.
[0029] 3) The catalyst provided in this application is simple to prepare, is not a precious metal, and has low production cost.
[0030] 4) Under preferred process conditions, the cyclopentane yield of the cyclopentane prepared by the method provided in this application can reach more than 60%, and the selectivity can reach 90.7%. Attached Figure Description
[0031] Figure 1 This is a gas chromatogram from Example 2 of this application. Detailed Implementation
[0032] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0033] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0034] The analysis method and the calculation of conversion rate and selectivity in the embodiments of this application are as follows: Qualitative and quantitative analysis of the products was performed offline using an Agilent 7890A gas chromatograph, with separation using an Agilent HP-5 capillary column and detection and analysis using a flame ionization detector (FID).
[0035] Example 1 1.45 Preparation and Application of Zr-H-HSZ Catalysts The synthesized HSZ molecular sieve gel precursor was loaded into a 100 mL crystallization vessel and placed in a rotary oven at 120 r / min for 12 h at 140 °C. The temperature was then increased to 170 °C for another 48 h of crystallization. After crystallization, the sample was filtered, washed, and dried. It was then acid-washed with 1 mol / L nitric acid for 30 h, washed with deionized water until neutral, and dried overnight in a 120 °C oven. Afterward, it was ground uniformly and calcined in a muffle furnace at 550 °C for 6 h to obtain H-HSZ molecular sieve. Then, 0.07 g of Zr(NO3)4·5H2O and 1 g of H-HSZ molecular sieve were placed in deionized water and microwave-digested at 90 °C for 2 h. Following the same conditions, the sample was acid-washed, dried, and calcined to obtain a zirconium-silicon molecular sieve catalyst with a zirconium content of 1.45%.
[0036] 0.15g of zirconium-silicon molecular sieve catalyst, 5g of acetonitrile, 4mL of 15% hydrogen peroxide aqueous solution and 2g of cyclopentane were added to a high-pressure reactor and reacted at 80℃ for 10h. The conversion rate of cyclopentane was 50% and the selectivity of cyclopentanol was 87%.
[0037] Example 2 2. Preparation and Application of Zr-H-HSZ Catalysts The synthesized HSZ molecular sieve gel precursor was loaded into a 100 mL crystallization vessel and placed in a rotary oven at 80 r / min for 12 h at 130 °C. The temperature was then increased to 170 °C for another 24 h of crystallization. After crystallization, the sample was filtered, washed, and dried. It was then acid-washed with 2 mol / L nitric acid for 20 h, washed with deionized water until neutral, and dried overnight in a 120 °C oven. Afterward, it was ground uniformly and calcined in a muffle furnace at 550 °C for 6 h to obtain H-HSZ molecular sieve. Then, 0.1 g of Zr(NO3)4·5H2O and 1 g of H-HSZ molecular sieve were placed in deionized water and microwave-digested at 80 °C for 4 h. Following the same conditions, the sample was acid-washed, dried, and calcined to obtain a zirconium-silicon molecular sieve catalyst with a zirconium content of 2%.
[0038] 0.15 g of zirconium-silicon molecular sieve catalyst, 5 g of methanol, 3 mL of 20% hydrogen peroxide aqueous solution, and 2 g of cyclopentane were added to a high-pressure reactor and reacted at 80 °C for 8 h. The cyclopentane conversion rate was 66.9%, and the cyclopentanol selectivity was 90.7% (e.g., ...). Figure 1 (As shown).
[0039] Example 3 5. Preparation and Application of Zr-H-HSZ Catalysts The synthesized HSZ molecular sieve gel precursor was loaded into a 100 mL crystallization vessel and placed in a rotary oven at 130 °C for 12 h at 60 r / min. The temperature was then increased to 160 °C for another 24 h of crystallization. After crystallization, the sample was filtered, washed, and dried. It was then acid-washed with 3 mol / L nitric acid for 10 h, washed with deionized water until neutral, and dried overnight in a 120 °C oven. After homogenization, the sample was calcined in a muffle furnace at 550 °C for 6 h to obtain H-HSZ molecular sieve. Then, 0.25 g of Zr(NO3)4·5H2O and 1 g of H-HSZ molecular sieve were placed in deionized water and microwave-digested at 60 °C for 6 h. Following the same conditions, the sample was acid-washed, dried, and calcined to obtain a zirconium-silicon molecular sieve catalyst with a zirconium content of 5%.
[0040] 0.15g of zirconium-silicon molecular sieve catalyst, 5g of tert-amyl alcohol, 1.2mL of 50% hydrogen peroxide aqueous solution and 2g of cyclopentane were added to a high-pressure reactor and reacted at 100℃ for 4h. The conversion rate of cyclopentane was 50.5% and the selectivity of cyclopentane alcohol was 48.9%.
[0041] Example 4 0.5 Preparation and Application of Zr-H-HSZ Catalyst The synthesized HSZ molecular sieve gel precursor was loaded into a 100 mL crystallization vessel and placed in a rotary oven at 130 °C for 12 h at a rotation speed of 60 r / min. The temperature was then increased to 160 °C for another 36 h of crystallization. After crystallization, the sample was filtered, washed, and dried. It was then acid-washed with 2 mol / L nitric acid for 20 h, washed with deionized water until neutral, and dried overnight in a 120 °C oven. Afterward, it was ground uniformly and calcined in a muffle furnace at 550 °C for 6 h to obtain H-HSZ molecular sieve. Then, 0.024 g of Zr(NO3)4·5H2O and 1 g of H-HSZ molecular sieve were placed in deionized water and microwave-digested at 80 °C for 4 h. Following the same conditions, the sample was acid-washed, dried, and calcined to obtain a zirconium-silicon molecular sieve catalyst with a zirconium content of 0.5%.
[0042] 0.15g of zirconium-silicon molecular sieve catalyst, 5g of methanol, 2mL of 30% hydrogen peroxide aqueous solution and 2g of cyclopentane were added to a high-pressure reactor and reacted at 80℃ for 8h. The conversion rate of cyclopentane was 32% and the selectivity of cyclopentanol was 78%.
[0043] Example 5 2. Application of Zr-H-HSZ catalyst 0.15g of the zirconium-silicon molecular sieve catalyst prepared in Example 2, 2g of methanol and 3g of acetonitrile as solvents, 2mL of 30% hydrogen peroxide aqueous solution and 2g of cyclopentane were added to a high-pressure reactor and reacted at 80℃ for 8h. The cyclopentane conversion rate was 50% and the cyclopentanol selectivity was 70.7%.
[0044] Example 6 1.45 Application of Zr-H-HSZ Catalyst 0.15g of the zirconium-silicon molecular sieve catalyst prepared in Example 1, 3g of methanol and 2g of tert-butanol as solvents, 2mL of 30% hydrogen peroxide aqueous solution and 2g of cyclopentane were added to a high-pressure reactor and reacted at 80℃ for 6h. The cyclopentane conversion rate was 55.6% and the cyclopentanol selectivity was 75.9%.
[0045] Comparative Example 1 Applications of 1.56 Zr-H-HSZ catalyst prepared by impregnation method First, 0.075g Zr(NO3)4·5H2O was dissolved in deionized water, and then 1g H-HSZ molecular sieve was added to it. After drying and calcination, the catalyst was obtained, in which the content of metallic zirconium was 1.56%.
[0046] 0.15g catalyst, 5g methanol, 3mL 20% hydrogen peroxide aqueous solution and 2g cyclopentane were added to a high-pressure reactor and reacted at 80℃ for 10h. The conversion rate of cyclopentane was 40% and the selectivity of cyclopentanol was 67%.
[0047] Comparative Example 2 Application of TS-1 catalyst 0.15g of the TS-1 catalyst, 5g of methanol, 2mL of 30% hydrogen peroxide aqueous solution and 2g of cyclopentane were added to a high-pressure reactor and reacted at 80℃ for 5h. The cyclopentane conversion rate was 26% and the cyclopentanol selectivity was 48%.
[0048] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing cyclopentanol, characterized in that, The preparation method includes: In a closed reactor, a mixture containing a catalyst, solvent, oxidant, and cyclopentane is reacted to yield cyclopentanol. The catalyst is a zirconium-silicon hierarchical porous molecular sieve catalyst.
2. The preparation method according to claim 1, characterized in that, The preparation method of the zirconium-silicon hierarchical porous molecular sieve catalyst includes the following steps: S1: The HSZ molecular sieve is crystallized, acid-treated (I), dried (I), and calcined (I) to obtain H-HSZ molecular sieve; S2: A mixture containing H-HSZ molecular sieve and zirconium salt is subjected to microwave-assisted digestion, acid treatment II, drying II, and calcination II to obtain a zirconium-silicon hierarchical porous molecular sieve catalyst.
3. The preparation method according to claim 2, characterized in that, The zirconium-silicon hierarchical porous molecular sieve catalyst contains 0.5% to 5% zirconium by mass. Preferably, the zirconium salt is selected from at least one of Zr(NO3)4·5H2O, ZrCl, Zr(CH3COO)4·4H2O, and Zr(SO4)2·4H2O.
4. The preparation method according to claim 2, characterized in that, In step S1, the crystallization rotation speed is 60-120 r / min, the crystallization temperature is 120-170℃, and the crystallization time is 12-72 h. Preferably, the conditions for acid treatment I and acid treatment II are independently 1-3 mol / L nitric acid solution, and washing for 10-30 h.
5. The preparation method according to claim 2, characterized in that, The temperatures for drying I and drying II are independently selected from 90 to 130°C, and the times are independently selected from 6 to 12 hours. Preferably, the temperatures for calcination I and calcination II are independently selected from 500 to 600°C, and the times are independently selected from 6 to 10 hours.
6. The preparation method according to claim 2, characterized in that, In step S2, the temperature of the microwave-assisted digestion is 60-90℃, and the time of the microwave-assisted digestion is 2-6 hours.
7. The preparation method according to claim 1, characterized in that, The mass ratio of the catalyst to the cyclopentane is 1:10-50; Preferably, the mass ratio of cyclopentane to solvent is 1:2 to 10; Preferably, the mass ratio of cyclopentane to the oxidant is 1:0.5 to 5.
8. The preparation method according to claim 1, characterized in that, The reaction temperature is 40–100°C, and the reaction time is 4–10 hours.
9. The preparation method according to claim 1, characterized in that, The oxidant is hydrogen peroxide, and the concentration of the hydrogen peroxide is 15-50%.
10. The preparation method according to claim 1, characterized in that, The solvent is selected from at least one of methanol, acetone, acetonitrile, and tert-amyl alcohol.