Alloy catalyst, its preparation method and its application in the preparation of cyclopentanone

Abstract

This invention discloses an alloy catalyst, comprising a support and a copper-ruthenium alloy supported on the support, wherein the copper-ruthenium alloy is: Cu 0.7 Ru 0.3 The alloy catalyst prepared by this invention can be used to prepare cyclopentanone. The catalyst has high activity, good stability, and low price. The reactants used in the reaction are renewable, widely distributed, and inexpensive. The preparation of cyclopentanone using the catalyst of this invention does not require the introduction of acid or alkali, which solves the problem of difficult acid treatment in the prior art. Furthermore, it is not corrosive to the reaction equipment, which is conducive to large-scale production.

Description

An alloy catalyst, its preparation method and its application in the preparation of cyclopentanone Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to an alloy catalyst, its preparation method, and its application in the preparation of cyclopentanone. Background Technology

[0002] Cyclopentanone is an important platform compound used in the preparation of chemicals such as rubber, resins, plastics, coatings, and solvents. Furthermore, cyclopentanone is widely used in pharmaceutical and pesticide synthesis. Moreover, in the life sciences, cyclopentanone is used as a neuroprotective agent to alleviate inflammation and cell death caused by damage to the central nervous system.

[0003] Currently, the industrial methods for producing cyclopentanone are as follows:

[0004] 1. The adipic acid method uses adipic acid as a raw material and barium hydroxide as a catalyst to prepare cyclopentanone through decarboxylation and condensation reactions. The main problems with this method are the difficulty in treating the waste acid solution, its extremely unfriendly environment, and the low purity of the product.

[0005] 2. Sodium hydroxide method: This method uses cyclohexanone and sodium hydroxide as raw materials to prepare cyclopentanone under high temperature and high pressure conditions. The main problem with this method is that it requires a high temperature and high pressure environment, resulting in high equipment costs.

[0006] On the other hand, the raw materials for the aforementioned processes all come from fossil fuels. Their extraction, transportation, and processing release large amounts of greenhouse gases and other pollutants, leading to air, water, and soil pollution, thus impacting the ecological environment and human health. Furthermore, fossil fuel reserves are limited and prices are unstable; therefore, over-reliance on fossil fuels for cyclopentanone production carries uncertainties.

[0007] Biomass is a renewable resource with better sustainability and environmental friendliness compared to fossil fuels, thus effectively alleviating fossil fuel shortages and environmental pollution. Compared to fossil fuels, biomass energy is more stable in price and lower in cost; therefore, catalytic conversion of biomass raw materials to produce cyclopentanone can reduce production costs and decrease dependence on fossil fuels.

[0008] Currently, furfural is the most commonly used raw material for the preparation of cyclopentanone from biomass. Existing technologies prepare furfural through the conversion of hemicellulose or xylose, but the reaction steps are complex and there are problems such as difficulty in handling acid and serious loss of heat energy. Summary of the Invention

[0009] The purpose of this invention is to provide an alloy catalyst, its preparation method and application, and a method for cyclopentanone preparation, so as to achieve one-step conversion to cyclopentanone, while reducing heat loss and solving the problem of waste acid treatment, thereby improving energy utilization efficiency.

[0010] To achieve the above objectives, the present invention provides an alloy catalyst, comprising a support and a copper-ruthenium alloy supported on the support, wherein the copper-ruthenium alloy is: Cu 0.7 Ru 0.3 .

[0011] Optionally, in some embodiments, the support comprises one or more of mesoporous molecular sieves, mesoporous carbon, SiO2, TiO2, and hydroxyapatite; and / or

[0012] The mesoporous molecular sieve includes SBA-15; the mesoporous carbon includes CMK-3; and / or

[0013] The loading of copper relative to the support is 10 wt.% to 30 wt.%; the loading of ruthenium relative to the support is 0.5 wt.% to 1.5 wt.%.

[0014] This invention provides a method for preparing an alloy catalyst, comprising the following steps:

[0015] Prepare a Cu precursor, filter, wash, and dry it;

[0016] Preparation of CuRu precursor;

[0017] Then, it is calcined in air, reduced in a mixed atmosphere of hydrogen and argon, and passivated in a mixed atmosphere of air and argon to obtain the final product.

[0018] Optionally, in some embodiments, the Cu precursor preparation method includes mixing a copper source and a support, adding deionized water and stirring until homogeneous, then adding ammonia to adjust the pH to 12-14, and then stirring and heating at 85-99°C until the pH reaches 6-8; and / or

[0019] The mass ratio of copper source to carrier is 0.38–1.14; the ammonia concentration in the ammonia stripping process is 25–28%; and / or

[0020] The filtration and washing method includes rinsing with deionized water 5 to 20 times during vacuum filtration; the drying temperature is 80 to 120°C, and the drying time is 12 to 100 hours; and / or

[0021] The CuRu precursor preparation method includes preparing a ruthenium source aqueous solution, then immersing the prepared ruthenium source aqueous solution onto the Cu precursor, immersing at room temperature for 12 hours, and then drying; and / or

[0022] The mass ratio of the ruthenium source to the support is 0.1–0.3; and / or

[0023] The calcination temperature is 400–800℃, and the time is 3–8 hours; and / or

[0024] The reduction temperature is 300–800°C, and the time is 3–12 hours; and / or

[0025] The passivation temperature is room temperature, and the passivation time is 8–24 hours; and / or

[0026] In the hydrogen-argon mixed atmosphere, the hydrogen / argon flow rate is 2 / 8; in the air-argon mixed atmosphere, the air / argon flow rate is 2 / 8; and / or

[0027] The copper source includes Cu(NO3)2·3H2O, CuCl2, and CuSO4; the ruthenium source includes RuCl3.

[0028] This invention provides a method for preparing an alloy catalyst through co-impregnation, comprising the following steps:

[0029] Add the carrier, then add an aqueous solution of copper source and ruthenium source, stir evenly and then dry;

[0030] The product is obtained by calcining in air, reducing in a mixed atmosphere of hydrogen and argon, and passivating in a mixed atmosphere of air and argon.

[0031] Optionally, in some embodiments, the mass ratio of the copper source to the carrier is 0.38 to 1.14; and / or

[0032] The calcination temperature is 400–800℃, and the time is 3–8 hours; and / or

[0033] The reduction temperature is 300–800°C, and the time is 3–12 hours; and / or

[0034] The passivation temperature is room temperature, and the passivation time is 8–24 hours; and / or

[0035] In the hydrogen-argon mixed atmosphere, the hydrogen / argon flow rate is 2 / 8; in the air-argon mixed atmosphere, the air / argon flow rate is 2 / 8; and / or

[0036] The copper source includes Cu(NO3)2·3H2O, CuCl2, and CuSO4; the ruthenium source includes RuCl3.

[0037] This invention provides an application of an alloy catalyst in the preparation of cyclopentanone, wherein the alloy is a copper-ruthenium alloy.

[0038] Optionally, in some embodiments, the copper-ruthenium alloy is: Cu 0.7 Ru 0.3 .

[0039] This invention provides a method for preparing cyclopentanone using an alloy catalyst, comprising the following steps:

[0040] Prepare a two-phase reaction system of sodium chloride aqueous solution / toluene organic solvent;

[0041] Add Cu 0.7 Ru 0.3 A catalyst and biomass feedstock are used to convert the biomass feedstock into cyclopentanone under a hydrogen atmosphere. Optionally, in some embodiments, Cu... 0.7 Ru 0.3 The ratio of catalyst to biomass feedstock is 5–20 wt.%; and / or

[0042] The biomass feedstock includes hemicellulose and its monomers; and / or

[0043] The hemicellulose includes one or more of xylose, arabinose, and xylulose; and / or

[0044] In the sodium chloride aqueous solution / toluene two-phase reaction system, the concentration of the sodium chloride aqueous solution is 2 wt.% to 15 wt.%, and the volume ratio of the sodium chloride aqueous solution to toluene is 1:0.1 to 10; and / or

[0045] The pressure of the hydrogen atmosphere is 2–8 MPa, and the reaction temperature is 140–240 °C.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] The alloy catalyst prepared by this invention can be used to prepare cyclopentanone. It exhibits high activity, good stability, and low cost. The reactants used in the reaction are renewable, widely distributed, and inexpensive. The catalyst eliminates the need for acid or alkali in the preparation of cyclopentanone, thus solving the problem of difficult acid treatment. Furthermore, it is non-corrosive to reaction equipment, facilitating large-scale production. Using the alloy catalyst prepared by this invention to prepare cyclopentanone is of great significance for my country's sustainable energy development, environmental protection, and the rapid achievement of its carbon neutrality and carbon peaking strategic goals.

[0048] The alloy catalyst of this invention is cheaper than precious metal catalysts and exhibits improved reactivity compared to them. Compared to other non-precious metal catalysts, the alloy catalyst of this invention possesses higher reactivity, chlorine resistance, and stability. Regarding heat loss, the catalyst of this invention enables the production of cyclopentanone in a single step, while existing biomass conversion processes require multiple steps. Therefore, it effectively reduces heat loss and is more conducive to the industrial production of cyclopentanone. Attached Figure Description

[0049] Figure 1 is the XRD pattern of the copper-ruthenium alloy catalyst prepared according to the present invention;

[0050] Figure 2 is an EDS-MAPPING surface scan of the copper-ruthenium alloy catalyst prepared according to the present invention;

[0051] Figure 3 is an EDS-MAPPING spot scan of the copper-ruthenium alloy catalyst prepared according to the present invention. Detailed Implementation

[0052] The present invention will be further described below with reference to specific embodiments, but this does not limit the present invention in any way.

[0053] Unless otherwise specified, the instruments, reagents, and materials used in the following embodiments are all conventional instruments, reagents, and materials already available in the prior art and can be obtained through legitimate commercial channels. Unless otherwise specified, the experimental methods and detection methods used in the following embodiments are all conventional experimental methods and detection methods already available in the prior art.

[0054] In a first aspect, the present invention provides an alloy catalyst comprising a support and a copper (Cu)ruthenium (Ru) alloy supported on the support.

[0055] The support includes one or more of mesoporous molecular sieves, mesoporous carbon, SiO2, TiO2, and hydroxyapatite; the mesoporous molecular sieve includes SBA-15; and the mesoporous carbon includes CMK-3.

[0056] The loading of Cu relative to the support is 10 wt.% to 30 wt.%; the loading of Ru relative to the support is 0.5 wt.% to 1.5 wt.%.

[0057] The chemical formula of the copper-ruthenium alloy is: Cu 0.7 Ru 0.3 .

[0058] Secondly, the present invention provides a method for preparing an alloy catalyst, comprising the following steps:

[0059] S11. Prepare Cu precursor by ammonia stripping method, filter, wash and dry;

[0060] S12. CuRu precursor was prepared using the impregnation method;

[0061] S13. Then, calcination is carried out in air, followed by reduction in a mixed atmosphere of hydrogen and argon, and passivation is performed in a mixed atmosphere of air and argon to obtain Cu. 0.7 Ru 0.3 catalyst;

[0062] In step S11, a copper source and carrier with a mass ratio of 0.38 to 1.14 are added, along with deionized water and stirred. Then, ammonia is added to adjust the pH to 12 to 14. The mixture is stirred and heated at 85 to 99°C until the pH reaches 6 to 8. The mixture is then filtered, washed, and dried.

[0063] The ammonia concentration is 25-28%; the filtration and washing method includes rinsing with deionized water 5-20 times during vacuum filtration; the drying temperature is 80-120℃ and the time is 12-100 hours.

[0064] In step S12, a ruthenium source aqueous solution is prepared, with a mass ratio of ruthenium source to support of 0.1 to 0.3. The solution is stirred evenly, and then the prepared ruthenium source aqueous solution is immersed in the Cu precursor at room temperature for 12 to 100 hours. After that, it is placed in an oven to dry overnight.

[0065] The copper source of the copper-ruthenium alloy includes Cu(NO3)2·3H2O, CuCl2, and CuSO4; the ruthenium source includes RuCl3.

[0066] In step S13, calcination is performed in an air atmosphere at a temperature of 400–800°C for 3–8 hours. After calcination, reduction is carried out in a mixed atmosphere of hydrogen and argon at 300–800°C for 3–12 hours. After cooling to room temperature, passivation is performed in a mixed atmosphere of air and argon for 8–24 hours to obtain Cu. 0.7 Ru 0.3 catalyst.

[0067] Reduction was carried out in an atmosphere with a hydrogen / argon flow rate of 2 / 8, and passivation was carried out in an atmosphere with an air / argon flow rate of 2 / 8.

[0068] Thirdly, the present invention provides another method for preparing an alloy catalyst, comprising the following steps:

[0069] S21. Add the carrier, then add the aqueous solutions of copper source and ruthenium source, stir evenly and then dry;

[0070] S22. Calcination is carried out in air at a temperature of 400–800℃ for 3–8 hours, followed by reduction in a mixed atmosphere of hydrogen and argon at a temperature of 300–800℃ for 3–12 hours. Finally, passivation is performed in a mixed atmosphere of air and argon for 8–24 hours to obtain Cu. 0.7 Ru 0.3 catalyst.

[0071] The copper source of the copper-ruthenium alloy includes Cu(NO3)2·3H2O, CuCl2, and CuSO4; the ruthenium source includes RuCl3.

[0072] The mass ratio of the copper source to the carrier is 0.38 to 1.14.

[0073] Fourthly, the present invention provides a method for preparing cyclopentanone, comprising the following steps:

[0074] S31. Prepare a two-phase reaction system of sodium chloride aqueous solution / toluene organic solvent;

[0075] S32. Add Cu under a hydrogen atmosphere. 0.7 Ru 0.3 A catalyst and biomass feedstock are used to convert the biomass feedstock into cyclopentanone.

[0076] Among them, Cu 0.7 Ru 0.3 The ratio of catalyst to biomass feedstock is 5–20 wt.%.

[0077] The biomass raw materials include hemicellulose and its monomers, such as one or more of xylan, xylose, arabinose, and xylulose.

[0078] In the sodium chloride aqueous solution / toluene two-phase reaction system, the concentration of the sodium chloride aqueous solution is 2 wt.% to 15 wt.%, and the volume ratio of the sodium chloride aqueous solution to toluene is 1:0.1 to 10.

[0079] The pressure of the hydrogen atmosphere is 2–8 MPa, and the reaction temperature is 140–240 °C.

[0080] Example 1

[0081] Take a 100mL round-bottom flask, add 1g of SBA-15 and 0.38g of Cu(NO3)2·3H2O, then add 20mL of deionized water. Fix the round-bottom flask in an oil bath using an iron stand, stir, and slowly add ammonia to adjust the pH to 13. Heat the oil bath to 90℃ until the pH reaches 7. Stop heating and stirring, remove the sample, filter and wash, and dry in an oven, labeling it 10-Cu / SBA-15. Place the dried 10-Cu / SBA-15 into a beaker, add 0.136g of 5wt.% RuCl3 solution to make the Ru loading on the catalyst 0.5wt.%. Then add an appropriate amount of water to the beaker and stir with a glass rod. After equal-volume impregnation, let the catalyst stand in a cool, windless place for 24 hours, then dry in an oven. The prepared precursors were named 10-Cu0.5-Ru / SBA-15 precursors. The prepared precursors were placed in a muffle furnace and calcined at 400℃ for 4 hours in air. Then, the calcined samples were placed in a tube furnace and reduced at 500℃ for 4 hours in a hydrogen-argon mixture. After reduction, the tube furnace was allowed to cool to room temperature, and the samples were passivated in an argon-air mixture for 24 hours. The samples were named 10-Cu. 0.7 0.5-Ru 0.3％ .

[0082] As shown in Figure 2, EDS-MAPPING surface scans show that Cu and Ru elements overlap, confirming the formation of an alloy.

[0083] As shown in Figure 3, EDS-MAPPING spot scanning showed that Cu, Ru, Si, and O elements were found at the same point. The Si and O elements originated from the carrier SBA-15, which confirms that the loading was successful.

[0084] Example 2

[0085] This embodiment is basically the same as Embodiment 1, except that the amount of Cu(NO3)2·3H2O added in this embodiment is 0.76g, denoted as 20-Cu. 0.7 0.5-Ru 0.3 .

[0086] Example 3

[0087] This embodiment is basically the same as Embodiment 1, except that the amount of Cu(NO3)2·3H2O added in this embodiment is 1.14g, denoted as 30-Cu. 0.7 0.5-Ru 0.3 .

[0088] 10-Cu 0.7 0.5-Ru 0.3 20-Cu 0.70.5-Ru 0.3 30-Cu 0.7 0.5-Ru 0.3 Xylose conversion experiments were conducted. 0.3 g xylose, 30 mg of the catalyst prepared in Examples 1-3 of this invention, and 0.6 g NaCl were added to a 100 mL reaction vessel. Then, 20 mL of deionized water and 10 mL of toluene were added to the reaction vessel. Hydrogen gas was introduced into the reaction vessel at 3 MPa, and the reaction was carried out at 160 °C and 500 rpm for 4 hours. The reaction results are shown in Table 1.

[0089] Table 1. Catalytic conversion of xylose to cyclopentanone using catalysts prepared in Examples 1-3 of this invention

[0090]

[0091] As shown in Table 1, in Cu 0.7 Ru 0.3 In the SBA-15 catalyst, different Cu loadings have a certain impact on the reaction. The results show that a Cu loading of 10 wt.% provides the best selectivity and yield for cyclopentanone. 0.7 Ru 0.3 When the copper loading in the SBA-15 catalyst is 20 wt.% or 30 wt.%, although the cyclopentanone yield is acceptable, it is still lower compared to 10-Cu. 0.7 0.5-Ru 0.3 The figure has decreased. This is because the conversion of xylose to cyclopentanone is an integrated reaction involving multiple reaction routes. Xylose first isomerizes to xylulose in an aqueous NaCl solution, then dehydrates to form furfural, which is subsequently hydrogenated to produce furfuryl alcohol. After the conversion of xylose to furfuryl alcohol, the reaction route will be divided into the following three routes:

[0092] 1. Furfuryl alcohol isomerizes to form hydroxycyclopentenone, which is then dehydrated and hydrogenated to form cyclopentanone, which can then be further hydrogenated to form cyclopentanol.

[0093] 2. Furfuryl alcohol is further hydrogenated to produce tetrahydrofurfuryl alcohol;

[0094] 3. Furfuryl alcohol undergoes hydrogenation and dechlorination to produce methylfuran, which is then further hydrogenated to produce methyltetrahydrofurfuryl alcohol.

[0095] Methyltetrahydrofurfuryl alcohol can also be generated from tetrahydrofurfuryl alcohol through a hydrogenation and dechlorination reaction.

[0096] The reaction route described above is as follows:

[0097]

[0098] As the Cu content increases, the following side reactions become more intense:

[0099] 1. Excessive hydrogenation of furfuryl alcohol produces tetrahydrofurfuryl alcohol;

[0100] 2. Furfuryl alcohol undergoes hydrogenation and dechlorination to produce methylfuran;

[0101] 3. Cyclopentanone undergoes excessive hydrogenation to form cyclopentanol.

[0102] Therefore, excessive Cu content leads to a decrease in the yield of cyclopentanone. The yield of cyclopentanone is highest, reaching 67.9%, when the Cu loading is 10 wt.%.

[0103] Example 4

[0104] 1 g of SBA-15 was added to a beaker; then 0.38 g of Cu(NO3)2·3H2O and 0.136 g of 5 wt.% RuCl3 aqueous solution were added for equal-volume impregnation. The mixture was then left to stand in a cool, windless place for 24 hours, and then dried in an oven. It was then calcined at 400℃ for 4 hours in air, and then reduced at 500℃ for 4 hours in a tube furnace under a mixture of hydrogen and argon. After reduction, the tube furnace was allowed to cool to room temperature, and then passivated for 24 hours under a mixture of argon and air to obtain a sample named 2-10-Cu. 0.7 0.5-Ru 0.3 .

[0105] Example 5

[0106] This embodiment is basically the same as Embodiment 4, except that the amount of Cu(NO3)2·3H2O added in this embodiment is 0.76g, denoted as 2-20-Cu. 0.7 0.5-Ru 0.3 .

[0107] Example 6

[0108] This embodiment is basically the same as Embodiment 4, except that the amount of Cu(NO3)2·3H2O added in this embodiment is 1.14g, denoted as 2-30-Cu. 0.7 0.5-Ru 0.3 .

[0109] 2-10-Cu 0.7 0.5-Ru 0.3 2-20-Cu 0.7 0.5-Ru 0.3 2-30-Cu 0.7 0.5-Ru 0.3Xylose conversion experiments were conducted. 0.3 g xylose, 30 mg of the catalyst prepared in Examples 4-6 of this invention, and 0.6 g NaCl were added to a 100 mL reactor. Then, 20 mL of deionized water and 10 mL of toluene were added to the reactor. Hydrogen gas was introduced into the reactor at 3 MPa, and the reaction was carried out at 160 °C and 500 rpm for 4 hours. The reaction results are shown in Table 2.

[0110] Table 2. Catalytic conversion of xylose to cyclopentanone using catalysts prepared in Examples 4-6 of this invention.

[0111]

[0112] As shown in Table 2, Cu prepared by the co-impregnation method 0.7 Ru 0.3 The / SBA-15 catalyst showed slightly lower cyclopentanone yield and selectivity compared to Example 1, with a maximum cyclopentanone yield of 67.6%. The reaction behavior was similar to that of the catalysts prepared by first distilling ammonia and then impregnating in Examples 1-3.

[0113] Example 7

[0114] Add 1g of SBA-15 to a beaker; then add 0.136g of RuCl3 (5wt.%) and 0.38g of Cu(NO3)2·3H2O aqueous solution, and perform equal-volume impregnation. Let it stand in a cool, windless place for 24 hours, then dry it in an oven. Next, calcine it at 400℃ for 4 hours in air, then place it in a tube furnace and reduce it at 500℃ for 4 hours under a mixture of hydrogen and argon. After reduction, allow the tube furnace to cool to room temperature, then passivate it for 24 hours under a mixture of argon and air, naming it 10-Cu. 0.7 0.5-Ru 0.3 .

[0115] Example 8

[0116] This embodiment is basically the same as Embodiment 7, except that the amount of RuCl3 added in this embodiment is 0.272g, denoted as 10-Cu. 0.7 1.0-Ru 0.3 .

[0117] Example 9

[0118] This embodiment is basically the same as Embodiment 7, except that the amount of RuCl3 added in this embodiment is 0.408g, denoted as 10-Cu. 0.7 1.5-Ru 0.3 .

[0119] 10-Cu 0.7 0.5-Ru 0.3 10-Cu0.7 1.0-Ru 0.3 10-Cu 0.7 1.5-Ru 0.3 Xylose conversion experiments were conducted. 0.3 g xylose, 30 mg of the catalyst prepared in Examples 7-9 of this invention, and 0.6 g NaCl were added to a 100 mL reactor. Then, 20 mL of deionized water and 10 mL of toluene were added to the reactor. Hydrogen gas was introduced into the reactor at 3 MPa, and the reaction was carried out at 160 °C and 500 rpm for 4 hours. The reaction results are shown in Table 3.

[0120] Table 3. Catalytic conversion of xylose to cyclopentanone using catalysts prepared in Examples 7-9 of this invention.

[0121]

[0122] As shown in Table 3, the Cu prepared in Examples 7-9 of this invention 0.7 Ru 0.3 In the SBA-15 catalyst, variations in the Ru content significantly affect the yield of cyclopentanone. With increasing Ru content, the yield of over-hydrogenation products such as tetrahydrofurfuryl alcohol and methyltetrahydrofurfuryl alcohol increases. Excessive Ru introduction significantly enhances the yield of Cu. 0.7 Ru 0.3 The hydrogenation activity of the SBA-15 catalyst exacerbates the side reactions in this process. Therefore, the highest yield of cyclopentanone is achieved when the Ru loading is 0.5 wt.%, reaching a maximum yield of 67.8%.

[0123] Example 10

[0124] Add 1g of SBA-15; then add 0.38g of Cu(NO3)2·3H2O and 0.136g of 5wt.% RuCl3 aqueous solution. After impregnation in equal amounts, place in a cool, windless place to stand for 24 hours, then dry in an oven. Calcinate at 300℃ in air atmosphere for 4 hours, then place in a tube furnace and reduce at 500℃ for 4 hours under a mixture of hydrogen and argon. After reduction, allow the tube furnace to cool to room temperature, then passivate under a mixture of argon and air for 24 hours, naming the product 300-10-Cu. 0.7 0.5-Ru 0.3 .

[0125] Example 11

[0126] This embodiment is basically the same as Embodiment 10, except that the calcination temperature in this embodiment is 400℃, denoted as 400-10-Cu. 0.7 0.5-Ru 0.3 .

[0127] Example 12

[0128] This embodiment is basically the same as Embodiment 10, except that the calcination temperature in this embodiment is 600℃, denoted as 600-10-Cu. 0.7 0.5-Ru 0.3 .

[0129] Example 13

[0130] This embodiment is basically the same as Embodiment 10, except that the calcination temperature in this embodiment is 800℃, denoted as 800-10-Cu. 0.7 0.5-Ru 0.3 .

[0131] Use 300-10-Cu 0.7 0.5-Ru 0.3 400-10-Cu 0.7 0.5-Ru 0.3 600-10-Cu 0.7 0.5-Ru 0.3 800-10-Cu 0.7 0.5-Ru 0.3 Xylose conversion experiments were conducted. 0.3 g xylose, 30 mg of the catalyst prepared in Examples 10-13 of this invention, and 0.6 g NaCl were added to a 100 mL reactor. Then, 20 mL of deionized water and 10 mL of toluene were added to the reactor. Hydrogen gas was introduced into the reactor at 3 MPa, and the reaction was carried out at 160 °C and 500 rpm for 4 hours. The reaction results are shown in Table 4.

[0132] Table 4. Catalysts prepared in Examples 10-13 of this invention for the catalytic conversion of xylose to cyclopentanone

[0133]

[0134] As shown in Table 4, the catalysts prepared at different calcination temperatures exhibit certain differences in performance. As shown in Figure 1, XRD characterization reveals that the catalysts calcined at 400 and 600℃ form Cu... 0.7 Ru 0.3 The formation of the alloy phase, due to the reaction occurring under Cl-containing, high-temperature conditions, significantly improves the catalyst's resistance to poisoning. The catalyst calcined at 300°C did not form Cu. 0.7 Ru 0.3The alloy phase is almost completely lost under these reaction conditions, and the main product is furfural (FF). When the calcination temperature is too high, the selectivity of cyclopentanone decreases. It is possible that excessively high calcination temperatures will lead to the sintering of the metal components, which is not conducive to the reaction. In Example 13, the main byproduct was furfural. It can be seen that excessively high calcination temperatures are not conducive to the hydrogenation activity of the catalyst.

[0135] Example 14

[0136] Add 1g of SBA-15, then add 0.38g of Cu(NO3)2·3H2O and 0.136g of 5wt.% RuCl3 aqueous solution. After impregnation in equal amounts, place in a cool, windless place to stand for 24 hours, then dry in an oven. Calcinate at 400℃ in air atmosphere for 4 hours, then place in a tube furnace and reduce at 200℃ for 4 hours under a mixture of hydrogen and argon. After reduction, allow the tube furnace to cool to room temperature, then passivate under a mixture of argon and air for 24 hours, naming the product 10-Cu. 0.7 0.5-Ru 0.3 -200.

[0137] Example 15

[0138] This embodiment is basically the same as Embodiment 14, except that the reduction temperature in this embodiment is 300℃, denoted as 10-Cu. 0.7 0.5-Ru 0.3 -300.

[0139] Example 16

[0140] This embodiment is basically the same as Embodiment 14, except that the reduction temperature in this embodiment is 400℃, denoted as 10-Cu. 0.7 0.5-Ru 0.3 -300.

[0141] Example 17

[0142] This embodiment is basically the same as Embodiment 14, except that the reduction temperature in this embodiment is 600℃, denoted as 10-Cu. 0.7 0.5-Ru 0.3 -600.

[0143] Example 18

[0144] This embodiment is basically the same as embodiment 14, except that the reduction temperature in this embodiment is 800℃, denoted as 10-Cu. 0.7 0.5-Ru 0.3 -800.

[0145] 10-Cu 0.7 0.5-Ru 0.3-200, 10-Cu 0.7 0.5-Ru 0.3 -300, 10-Cu 0.7 0.5-Ru 0.3 -500, 10-Cu 0.7 0.5-Ru 0.3 -600, 10-Cu 0.7 0.5-Ru 0.3 Xylose conversion experiments were conducted at -800°C. 0.3 g xylose, 30 mg of the catalyst prepared in Examples 14-18 of this invention, and 0.6 g NaCl were added to a 100 mL reactor. Then, 20 mL of deionized water and 10 mL of toluene were added to the reactor. Hydrogen gas was introduced into the reactor at 3 MPa, and the reaction was carried out at 160°C and 500 rpm for 4 hours. The reaction results are shown in Table 5.

[0146] Table 5. Catalysts prepared in Examples 14-18 of this invention for the catalytic conversion of xylose to cyclopentanone

[0147]

[0148]

[0149] As shown in Table 5, the catalysts at different reduction temperatures exhibit different performances. The catalysts perform better at reduction temperatures of 500–600 °C. When the reduction temperature is too low, the catalysts are not fully reduced, resulting in poor hydrogenation performance and a higher amount of furfural byproduct. When the reduction temperature is too high, the metal components may be sintered, which also leads to a higher amount of furfural byproduct.

[0150] Examples 19-26

[0151] 10-Cu 0.7 0.5-Ru 0.3 Xylose conversion experiments were conducted. 0.3 g xylose and 30 mg of the catalyst prepared in Example 1 of this invention were added to a 100 mL reactor at concentrations of 0 wt.%, 1 wt.%, 2 wt.%, 3 wt.%, 5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%, respectively. Then, 20 mL of deionized water and 10 mL of toluene were added to the reactor. The reactor was purged with hydrogen gas at 3 MPa, and the reaction was carried out at 160 °C and 500 rpm for 4 hours. The reaction results are shown in Table 6.

[0152] Table 6. Catalytic conversion of xylose to cyclopentanone using the catalyst prepared in Example 1 of the present invention in sodium chloride solutions of different concentrations.

[0153]

[0154]

[0155] As shown in Table 6, the concentration of NaCl significantly affects the product distribution of the reaction. When there is no sodium chloride in the reaction system, the catalyst is not poisoned and exhibits strong hydrogenation performance. As is well known, Ru and Cu are commonly used metal active components in the hydrogenation of sugars to prepare sugar alcohols. Therefore, xylose, as the reaction substrate, is entirely hydrogenated to xylitol. When the concentration of NaCl aqueous solution is 2 wt.%, cyclopentanone begins to form, but the yield is not considerable, and tetrahydrofurfuryl alcohol appears as the main byproduct. This is because the catalyst's hydrogenation activity is too strong, causing the reaction intermediate furfuryl alcohol to be over-hydrogenated to tetrahydrofurfuryl alcohol. It is worth noting that although the catalyst exhibits excessive hydrogenation performance, the byproduct is not xylitol. This indicates that the addition of sodium chloride can effectively promote the isomerization reaction of xylose, converting it into xylulose, which is then further dehydrated and hydrogenated to furfuryl alcohol. As the NaCl concentration continues to increase, it can be clearly seen that the hydrogenation performance of the catalyst gradually weakens. When the NaCl concentration reaches 20 wt.%, the hydrogenation activity of the catalyst is completely lost. Therefore, the only reaction product is furfural, which is converted from xylose through isomerization and dehydration.

[0156] Examples 27-34

[0157] 10-Cu 0.7 0.5-Ru 0.3 Xylose conversion experiments were conducted. 0.3 g xylose, 30 mg of the catalyst prepared in Example 1 of this invention, and 0.6 g NaCl were added to a 100 mL reactor. Then, 20 mL of deionized water and 10 mL of toluene were added to the reactor. Hydrogen gas was introduced into the reactor at pressures of 0 MPa, 1 MPa, 2 MPa, 3 MPa, 5 MPa, 8 MPa, and 10 MPa, respectively. The reaction was carried out at 160 °C and 500 rpm for 4 hours. The reaction results are shown in Table 7.

[0158] Table 7. Catalytic conversion of xylose to cyclopentanone by the catalyst prepared in Example 1 of the present invention under different hydrogen pressures.

[0159]

[0160] As shown in Table 7, when the hydrogen pressure is too low, furfural, which is converted from xylose isomerization and dehydration, cannot be completely hydrogenated to prepare furfuryl alcohol. Therefore, the yield of cyclopentanone is not optimistic under the reaction conditions of low hydrogen pressure. With the increase of hydrogen pressure, the hydrogenation reaction intensifies, and furfural is completely converted to furfuryl alcohol, which is then further converted to cyclopentanone. The yield of cyclopentanone is highest when the hydrogen pressure is 3 MPa. However, when the hydrogen pressure is too high, the hydrogenation and dechlorination of furfuryl alcohol to produce methylfuran and the excessive hydrogenation of furfuryl alcohol to produce tetrahydrofurfuryl alcohol are intensified, leading to a decrease in the yield of cyclopentanone.

[0161] Examples 35-40

[0162] 10-Cu 0.7 0.5-Ru 0.3 Xylose conversion experiments were conducted. 0.3 g xylose, 30 mg of the catalyst prepared in Example 1 of this invention, and 0.6 g NaCl were added to a 100 mL reactor. Then, 20 mL of deionized water and 10 mL of toluene were added to the reactor. The reactor was purged with 2 MPa hydrogen gas, and the reaction was carried out at 500 rpm at temperatures of 130 °C, 140 °C, 160 °C, 180 °C, 200 °C, and 240 °C for 4 hours. The reaction results are shown in Table 8.

[0163] Table 8. Catalytic conversion of xylose to cyclopentanone by the catalyst prepared in Example 1 of the present invention at different reaction temperatures.

[0164]

[0165] As shown in Table 8, the reaction temperature has a certain impact on this reaction. At lower temperatures, the following two factors affect the formation of cyclopentanone: 1. Xylose is difficult to convert to furfural through isomerization and dehydration reactions; 2. Furfuryl alcohol is difficult to isomerize to form cycloketones. When the reaction temperature is too high, although the types of products do not change much, the carbon balance of the reaction becomes very poor. This may be because at high temperatures, furfural, furfuryl alcohol, and cyclopentanone will all undergo polymerization reactions to form compounds with larger molecules that are difficult to detect in gas chromatography. The applicant has also attempted to prepare alloys by combining other metals such as Pt and Rh with Ru. Even if some metals form alloy phases, they do not exhibit selectivity for the reaction of this invention.

[0166] For anyone skilled in the art, many possible variations and modifications can be made to the technical solutions of this invention, or equivalent embodiments can be modified based on the disclosed technical content, without departing from the scope of the technical solutions of this invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this invention without departing from the content of the technical solutions of this invention should still fall within the protection scope of the technical solutions of this invention.

Claims

1. A method for preparing cyclopentanone using an alloy catalyst, characterized in that, Includes the following steps: Prepare a two-phase reaction system of sodium chloride aqueous solution / toluene organic solvent; add Cu 0.7 Ru 0.3 A catalyst and biomass feedstock are used to convert the biomass feedstock into cyclopentanone under a hydrogen atmosphere; the biomass feedstock is xylose; the Cu... 0.7 Ru 0.3 The catalyst includes a support and a copper-ruthenium alloy supported on the support, wherein the copper-ruthenium alloy is: Cu 0.7 Ru 0.3 The carrier is SBA-15; in the sodium chloride aqueous solution / toluene two-phase reaction system, the concentration of the sodium chloride aqueous solution is 2 wt.%~15 wt.%, and the volume ratio of the sodium chloride aqueous solution to toluene is 1:0.1~10; the pressure of the hydrogen atmosphere is 2~8 MPa, and the reaction temperature is 140~240℃.

2. The method according to claim 1, characterized in that, The loading of copper relative to the carrier is 10 wt.% to 30 wt.%; the loading of ruthenium relative to the carrier is 0.5 wt.% to 1.5 wt.%.

3. The method according to claim 1, characterized in that, The Cu 0.7 Ru 0.3 The catalyst preparation method includes the following steps: preparing a Cu precursor, filtering, washing and drying; preparing a CuRu precursor; then calcining in air, then reducing in a mixed atmosphere of hydrogen and argon, and then passivating in a mixed atmosphere of air and argon to obtain the catalyst; the Cu precursor preparation method includes mixing a copper source and a support, adding deionized water and stirring evenly, then adding ammonia to adjust the pH to 12-14, and then stirring and heating at 85-99℃ until the pH reaches 6-8; the CuRu precursor preparation method includes preparing a ruthenium source aqueous solution, then immersing the prepared ruthenium source aqueous solution onto the Cu precursor, immersing at room temperature for 12 hours, and then drying.

4. The method according to claim 3, characterized in that, The mass ratio of copper source to support is 0.38~1.14; the ammonia concentration in the ammonia stripping method is 25~28%; and / or the filtration and washing method in the preparation of Cu precursor includes rinsing with deionized water 5~20 times during vacuum filtration, the drying temperature is 80~120℃, and the drying time is 12~100 hours; and / or the mass ratio of ruthenium source to support is 0.1~0.3; and / or the calcination temperature is 400~800℃, and the time is 3~8 hours; and / or the reduction temperature is 300~800℃, and the time is 3~12 hours; and / or the passivation temperature is room temperature, and the passivation time is 8~24 hours; and / or the copper source includes Cu(NO3)2·3H2O, CuCl2, CuSO4; the ruthenium source includes RuCl3.

5. The method according to claim 1, characterized in that, The Cu 0.7 Ru 0.3 The co-impregnation preparation method of the catalyst includes the following steps: adding a support, then adding an aqueous solution of copper source and ruthenium source, stirring evenly and drying; calcining in air, then reducing in a mixed atmosphere of hydrogen and argon, and passivating in a mixed atmosphere of air and argon to obtain the catalyst.

6. The method according to claim 5, characterized in that, The mass ratio of copper source to carrier is 0.38~1.14; and / or the calcination temperature is 400~800℃, and the time is 3~8 hours; and / or the reduction temperature is 300~800℃, and the time is 3~12 hours; and / or the passivation temperature is room temperature, and the passivation time is 8~24 hours; and / or the copper source includes Cu(NO3)2·3H2O, CuCl2, and CuSO4; the ruthenium source includes RuCl3.

7. The method according to claim 1, characterized in that, Cu 0.7 Ru 0.3 The ratio of catalyst to biomass feedstock is 5~20 wt.%.

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