A ruthenium-metal oxide catalyst, its preparation method and use in the synthesis of 1,5-pentanediol
By preparing a ruthenium-metal oxide catalyst and catalyzing the hydrogenation and ring-opening of tetrahydrofurfuryl alcohol in aqueous solution under low pressure and low temperature conditions, the problems of high catalyst cost and harsh reaction conditions in the prior art were solved, realizing the efficient and environmentally friendly preparation of 1,5-pentanediol, which is suitable for industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2022-11-16
- Publication Date
- 2026-05-29
AI Technical Summary
Existing methods for the catalytic hydrogenation and ring-opening of tetrahydrofurfuryl alcohol to prepare 1,5-pentanediol involve high costs and demanding reaction conditions due to the use of ultra-precious metal catalysts, making them unsuitable for large-scale industrial production.
A ruthenium-metal oxide catalyst, comprising a support and ruthenium and metal oxides supported on the surface of the support, is prepared by impregnation, drying and reduction, and the reaction is carried out in an aqueous solution at low pressure and temperature.
This method enables the efficient preparation of 1,5-pentanediol under relatively low pressure and temperature, making it suitable for large-scale industrial production. Furthermore, the reaction system is environmentally friendly and pollution-free.
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Abstract
Description
Technical Field
[0001] This invention relates to the fields of biomass technology and catalysis technology, and in particular to a ruthenium-metal oxide catalyst, its preparation method, and its application in the synthesis of 1,5-pentanediol. Background Technology
[0002] Currently, most organic chemical raw materials come from fossil resources such as petroleum. Biomass, as a resource with advantages such as wide distribution, environmental friendliness, abundant reserves, and especially zero greenhouse gas emissions, is one of the most promising sources of organic chemical raw materials that can replace fossil resources.
[0003] Tetrahydrofurfuryl alcohol is an important biomass-derived platform compound. 1,5-Pentanediol can be prepared by selective hydrogenation ring-opening. 1,5-Pentanediol is an important α,ω-diol, a colorless, viscous liquid miscible with water, low-molecular-weight alcohols, and acetone, but relatively insoluble in aliphatic and aromatic hydrocarbons. It is widely used in the manufacture of fine chemicals such as polyurethanes, polyesters, plasticizers, inkjet inks or inks, coatings, fragrances, cosmetics, and skincare products.
[0004] The following are some of the reported techniques for the catalytic hydrogenation and ring-opening of tetrahydrofurfuryl alcohol to prepare 1,5-pentanediol. The literature (Chemical Communications, 2009, 15(15): 2035-2037) reports the use of the catalyst Rh-ReO. x The selective hydrogenation and cracking of the CO bond in tetrahydrofurfuryl alcohol (THF) using SiO2 catalysis to produce 1,5-pentanediol was achieved using a 5% aqueous solution of THF as a raw material. The reaction was carried out at 8 MPa hydrogen pressure and 120°C for 24 hours, achieving a THF conversion of 96.2% and a 1,5-pentanediol selectivity of 80.1%. However, this reaction requires excessively high pressure, posing significant safety risks. Furthermore, rhodium and rhenium are rare and precious metals, resulting in high catalyst costs and hindering large-scale production. Chinese patent CN110102296A discloses a catalyst A / WO3-SiO2 (A being one of Pt, Rh, or Ru), which catalyzes the selective hydrogenation and cracking of THF to 1,5-pentanediol under certain conditions, achieving a selectivity of over 90% and a conversion of approximately 20%. However, this method requires high temperatures and stringent reaction conditions. A previous study (Chem. Lett. 2018, 47, 103-106) reported the selective hydrogenation of tetrahydrofurfuryl alcohol to 1,5-pentanediol using Ru / Ni-Y₂O₃ catalyst in an isopropanol solution containing decahydronaphthalene. The tetrahydrofurfuryl alcohol concentration was 1 mol / L, the reaction conditions were 2 MPa hydrogen pressure and 150 °C, and the reaction time was 24 h. The results showed that the conversion rate of tetrahydrofurfuryl alcohol was 80.8%, and the selectivity for 1,5-pentanediol was 74.9%. This method requires a large amount of organic solvent, which is more expensive than using water-based solvents and is also environmentally unfriendly.
[0005] Existing methods for the selective hydrogenation cracking of tetrahydrofurfuryl alcohol to prepare 1,5-pentanediol mainly use ultra-precious metals such as Ir and Rh, which have technical problems such as high catalyst cost and harsh reaction conditions, which are not conducive to large-scale industrial production. Summary of the Invention
[0006] According to one aspect of this application, a ruthenium-metal oxide catalyst is provided, the ruthenium-metal oxide catalyst comprising a support, ruthenium supported on the surface of the support, and a metal oxide supported on the surface of the support;
[0007] The metal oxide is selected from at least one of the following: oxides of molybdenum, oxides of vanadium, oxides of cerium, and oxides of lanthanum.
[0008] The support is selected from at least one of SiO2, Al2O3, and molecular sieve;
[0009] Optionally, the silica-to-alumina ratio of the molecular sieve is 20 to 600;
[0010] Optionally, the silica-alumina ratio of the molecular sieve is any value among 20, 50, 100, 200, 300, 400, 500, and 600, or a range between any two.
[0011] Optionally, the molecules are screened from at least one of MCM-41, SBA-15, and ZSM5;
[0012] The ruthenium content in the ruthenium-metal oxide catalyst is 0.1–10 wt%.
[0013] Optionally, the ruthenium content in the ruthenium-metal oxide catalyst is any value or a range between 0.1 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, and 10 wt%.
[0014] The metal element in the metal oxide has a mass content of 0.1 to 10 wt% in the ruthenium-metal oxide catalyst.
[0015] Optionally, the mass content of the metal element in the metal oxide in the ruthenium-metal oxide catalyst is any value or a range between 0.1 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, and 10 wt%.
[0016] The ruthenium-metal oxide catalyst needs to be reduced before application to reduce ruthenium to its elemental state.
[0017] According to another aspect of this application, a method for preparing the above-mentioned ruthenium-metal oxide catalyst is provided, comprising the following steps:
[0018] The support was immersed in an aqueous solution containing a ruthenium precursor and a metal oxide, and then dried to obtain the ruthenium-metal oxide catalyst.
[0019] The ruthenium precursor is selected from at least one of RuCl3, RuBr3, and Ru(CH3COO)3;
[0020] In the aqueous solution containing ruthenium precursor and metal oxide, the mass content of the ruthenium precursor is 8-10 wt%, based on the mass of ruthenium element;
[0021] Optionally, in the aqueous solution containing the ruthenium precursor and the metal oxide, the mass content of the ruthenium precursor is any value among 8 wt%, 9 wt%, and 10 wt%, or a range between any two.
[0022] In the aqueous solution containing ruthenium precursor and metal oxide, the mass content of the metal oxide is 2-20 wt%, based on the mass of ruthenium.
[0023] Optionally, in the aqueous solution containing the ruthenium precursor and the metal oxide, the mass content of the metal oxide is any value selected from 2wt%, 5wt%, 10wt%, 15wt%, and 20wt%, or a range between any two.
[0024] The mass ratio of the carrier to the aqueous solution containing the ruthenium precursor and the metal oxide is 1 to 3.
[0025] The soaking time is 20–24 hours;
[0026] Optionally, the immersion time is any value among 20h, 21h, 22h, 23h, and 24h, or a range between any two.
[0027] Stirring is performed during the impregnation process;
[0028] The drying temperature is 110–130°C;
[0029] Optionally, the drying temperature is any value among 110°C, 120°C, and 130°C, or a range between any two.
[0030] The drying time is 8 to 15 hours.
[0031] Optionally, the drying time is any value among 8h, 9h, 10h, 11h, 12h, 13h, 14h, and 15h, or a range between any two.
[0032] According to another aspect of this application, a method for synthesizing 1,5-pentanediol is provided, comprising the following steps:
[0033] In a reactor, hydrogen gas and an aqueous solution containing tetrahydrofurfuryl alcohol are contacted with a catalyst to react and obtain a product containing 1,5-pentanediol.
[0034] The catalyst is selected from the ruthenium-metal oxide catalyst described above or the ruthenium-metal oxide catalyst prepared by the above preparation method.
[0035] The volume ratio of hydrogen gas to an aqueous solution containing tetrahydrofurfuryl alcohol is 3:2;
[0036] In the aqueous solution containing tetrahydrofurfuryl alcohol, the content of tetrahydrofurfuryl alcohol is 5-60 wt%.
[0037] Optionally, in the aqueous solution containing tetrahydrofurfuryl alcohol, the content of tetrahydrofurfuryl alcohol is any value or a range between any two of 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, and 60wt%.
[0038] The reaction temperature is 100–200°C;
[0039] Optionally, the reaction temperature is any value or a range between 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, and 200°C.
[0040] The reaction time is 2–8 hours;
[0041] Optionally, the reaction time is any value among 2h, 3h, 4h, 5h, 6h, 7h, and 8h, or a range between any two.
[0042] The reaction pressure is 0.1–10 MPa.
[0043] Optionally, the pressure of the reaction is any value or a range between 0.1 MPa, 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, and 10 MPa.
[0044] The reactor is a batch reactor.
[0045] The catalyst is reduced;
[0046] The reduction is hydrogen reduction;
[0047] The temperature for hydrogen reduction is 300–350°C;
[0048] Optionally, the temperature for hydrogen reduction is any value among 300°C, 310°C, 320°C, 330°C, 340°C, and 350°C, or a range between any two.
[0049] The hydrogen reduction time is 2-3 hours;
[0050] Optionally, the hydrogen reduction time is any value among 2h, 2.5h, and 3h, or a range between any two.
[0051] The hydrogen flow rate for hydrogen reduction is 10–40 mL / min.
[0052] Optionally, the hydrogen flow rate for hydrogen reduction is any value among 10 mL / min, 20 mL / min, 30 mL / min, and 40 mL / min, or a range between any two.
[0053] The reduction also includes formaldehyde reduction, NaBH4 reduction, or ethylene glycol reduction.
[0054] The beneficial effects that this application can produce include:
[0055] The synthetic method for preparing 1,5-pentanediol provided by this invention has the following advantages: the pressure is relatively low and the temperature is not high, which can better meet the needs of large-scale industrialization; the reaction system is an aqueous system, which will not put too much pressure on the environment. Detailed Implementation
[0056] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0057] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased commercially.
[0058] Example 1
[0059] Catalyst preparation: 1.4660 g of 30% RuCl3 and 0.1021 g of ammonium molybdate were weighed into a beaker, and 7.05 g of water was added. After the solids dissolved, 4.7 g of silica was added while stirring. The mixture was stirred until homogeneous, and after standing for 24 h, it was transferred to a 120℃ oven to dry for 12 h. After drying, it was removed, cooled to room temperature, and then ground into powder. The obtained catalyst was Ru-MoO. x / SiO2.
[0060] Catalyst reduction: First, weigh 0.2g of catalyst into a tubular furnace reactor. Then, purge with nitrogen for 10 minutes to purge air, followed by purging with hydrogen for 10 minutes to fill the reactor with hydrogen. The gas flow rate for both purging processes is 20mL / min. Then, heat the tubular furnace to 350℃ from room temperature at a rate of 5℃ / min, maintain the temperature at 350℃ for 120 minutes, and finally allow it to cool naturally to room temperature.
[0061] Catalytic conversion to prepare 1,5-pentanediol: First, weigh 2g of tetrahydrofurfuryl alcohol and 18g of water into a reaction vessel, add a magnetic stir bar, quickly add the activated catalyst, and then close the reaction vessel. Next, purge the reaction vessel with hydrogen gas to 3.6 MPa, release the hydrogen gas, and then purge again to 3.6 MPa, repeating this process 5-8 times to purge the air from the reaction vessel, before filling it with hydrogen gas at 3.6 MPa. Then, raise the temperature to 150℃ at the maximum rate, maintain this temperature for 6 hours, and then allow it to cool naturally to room temperature. Finally, analyze the composition of the system after the reaction.
[0062] Example 2
[0063] Catalyst preparation: 1.4660 g of 30% RuCl3 and 0.0893 g of vanadium pentoxide were weighed into a beaker, and other conditions were the same as in Example 1. The resulting catalyst was Ru-VO2. x / SiO2.
[0064] The catalyst activation process and catalytic conversion process are the same as in Example 1.
[0065] Example 3
[0066] Catalyst preparation: 1.4660 g of 30% RuCl3 and 0.1549 g of cerium nitrate hexahydrate were weighed into a beaker, and other conditions were the same as in Example 1. The resulting catalyst was Ru-CeO. x / SiO2.
[0067] The catalyst activation process and catalytic conversion process are the same as in Example 1.
[0068] Example 4
[0069] The temperature of the reactor during the catalytic conversion process was kept constant at 200℃, and other conditions were the same as in Example 1.
[0070] Example 5
[0071] The reactor pressure for the catalytic conversion process was controlled at 6 MPa, and other conditions were the same as in Example 1.
[0072] Example 6
[0073] The reaction time for the catalytic conversion process was controlled at 12 h, and other conditions were the same as in Example 1.
[0074] After the reaction was completed, the resulting reaction solution was quantitatively analyzed by gas chromatography, and the results are shown in Tables 1 and 2:
[0075] Table 1. Performance results of the catalysts prepared in Examples 1-2 of this invention.
[0076]
[0077] Table 2 shows the analysis results of the product composition of the reaction system in Examples 1 and 4-6 of this invention.
[0078]
[0079]
[0080] From the above results, we can conclude that MoO x Compared to other metal oxides in the examples, these methods were most effective in improving the selectivity of 1,5-pentanediol. Increasing the temperature, pressure, and reaction time all significantly improved the conversion rate of tetrahydrofurfuryl alcohol, but the selectivity decreased. This is likely due to further side reactions occurring in 1,5-pentanediol. From a production efficiency perspective, a hydrogen pressure of 6 MPa, a reaction temperature of 150°C, and a reaction time of 6 h are the optimal reaction conditions. These conditions are relatively mild and conducive to large-scale industrial application.
[0081] 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 synthesizing 1,5-pentanediol, characterized in that, Includes the following steps: In a reactor, hydrogen gas and an aqueous solution containing tetrahydrofurfuryl alcohol are contacted with a ruthenium-metal oxide catalyst to react and obtain a product containing 1,5-pentanediol. The ruthenium-metal oxide catalyst includes a support, ruthenium supported on the surface of the support, and a metal oxide supported on the surface of the support; The metal oxide is an oxide of molybdenum; The carrier is SiO2; The preparation method of the ruthenium-metal oxide catalyst includes the following steps: The support was immersed in an aqueous solution containing ruthenium precursor and ammonium molybdate, dried, and reduced with hydrogen to obtain the ruthenium-metal oxide catalyst. The temperature for hydrogen reduction is 300~350℃; The hydrogen reduction time is 2-3 hours; The hydrogen flow rate for hydrogen reduction is 10~40 mL / min.
2. The method according to claim 1, characterized in that, The ruthenium content in the ruthenium-metal oxide catalyst is 0.1~10 wt%; The metal element in the metal oxide has a mass content of 0.1~10wt% in the ruthenium-metal oxide catalyst.
3. The method according to claim 1, characterized in that, The ruthenium precursor is selected from at least one of RuCl3 and Ru(CH3COO)3.
4. The method according to claim 1, characterized in that, The soaking time is 20-24 hours; Stirring is performed during the impregnation process; The drying temperature is 110~130℃; The drying time is 8-15 hours.
5. The method according to claim 1, characterized in that, The volume ratio of hydrogen gas to an aqueous solution containing tetrahydrofurfuryl alcohol is 3:2; In the aqueous solution containing tetrahydrofurfuryl alcohol, the content of tetrahydrofurfuryl alcohol is 5-60 wt%. The reaction temperature is 100~200℃; The reaction time is 2-8 hours; The reaction pressure is 0.1~10 MPa.
6. The method according to claim 1, characterized in that, The reactor is a batch reactor.