A method for preparing aromatic ketone compounds from aromatic compounds
By using a nanostructure of composite transition metal oxides and nitrogen-doped carbon-supported cobalt-based catalysts, the problem of selective oxidation of aromatic hydrocarbons has been solved, achieving efficient and environmentally friendly catalytic effects and expanding the applicability of the catalyst.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2024-12-09
- Publication Date
- 2026-06-09
AI Technical Summary
Existing technologies struggle to efficiently and selectively oxidize aromatic hydrocarbons under mild conditions, and the heterogeneity of homogeneous catalysts presents challenges in separation and contamination.
By employing a composite of two heterogeneous non-precious metal catalysts, a nanostructure is formed by mixing transition metal oxides and nitrogen-doped carbon-supported cobalt-based catalysts to improve catalytic performance and achieve selective oxidation of aromatic hydrocarbons.
The catalyst achieves efficient and selective oxidation of aromatic hydrocarbons under mild conditions, reducing production costs and environmental pollution, and expanding the applicable range of the catalyst.
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Abstract
Description
Technical Field
[0001] This application relates to a method for preparing aromatic ketone compounds from aromatic compounds, which belongs to the field of chemical engineering. Background Technology
[0002] Aromatic compounds are widely distributed and structurally complex. The catalytic oxidation of aromatic hydrocarbons is a crucial process in modern petrochemicals, yielding a range of chemicals such as aldehydes, ketones, acids, and esters, which have wide applications in pharmaceuticals, food, and chemicals. Hydrocarbons themselves do not contain oxygen atoms; the oxidation process involves activating the CH bonds and introducing oxygen-containing functional groups. However, the CH bonds in the aromatic side chains exhibit varying activities during oxidation due to factors such as their position and the types of adjacent groups. Developing a highly active catalytic system for the oxidation of various types of aromatic hydrocarbons has significant practical value for the fine chemical industry.
[0003] Developing efficient non-precious metal catalysts for the selective oxidation of CH bonds under relatively mild conditions is an important research direction in the catalytic oxidation of aromatics by molecular oxygen. In industry, homogeneous metal salts of Co and Mn are commonly used to oxidize aromatics. Considering the costs and pollution associated with subsequent separation, heterogeneous homogeneous catalysts are an important means of selectively oxidizing aromatic compounds. Summary of the Invention
[0004] This method utilizes a combination of two heterogeneous non-precious metal catalysts to achieve highly efficient and selective oxidation of aromatic hydrocarbons.
[0005] In this application, the active component of the catalyst is prepared as a uniformly dispersed nanostructure to improve the catalytic performance. The types of metals in the two catalysts greatly affect the catalytic performance of aromatic hydrocarbons. This invention provides a catalytic strategy combining a transition metal oxide and a nitrogen-doped carbon-supported cobalt-based catalyst to improve the selectivity of aromatic hydrocarbon oxidation.
[0006] According to one aspect of this application, a method for preparing aromatic ketone compounds from aromatic compounds is provided, comprising the following steps:
[0007] In a reactor under an oxygen-containing atmosphere, a solvent, an aromatic compound, a transition metal oxide, and a nitrogen-doped carbon-supported cobalt-based catalyst are mixed and reacted to obtain aromatic ketone compounds.
[0008] The substance is selected from at least one of fluorene, tetrahydronaphthalene, ethylbenzene, 3,6-dimethoxyfluorene, diphenylmethane, 2-phenyl-1-acetophenone, anthrone, 9,10-dihydroanthracene, oxanthracene, and thioxanthracene;
[0009] The transition metal oxide is selected from at least one of MnO2, Fe3O4, CuO, Ni2O3, and V2O5;
[0010] In the nitrogen-doped carbon-supported cobalt-based catalyst, the cobalt content is 0.1–10 wt%. The content of other metal elements (i.e., metal elements in nano-metal oxides) is 0–5 wt%.
[0011] The nitrogen-doped carbon-supported cobalt-based catalyst is obtained through the following steps:
[0012] Cobalt salt, nitrogen-containing compound, nano-metal oxide, and organic solvent are mixed, dried, pyrolyzed under an inactive gas atmosphere, mixed with sulfuric acid aqueous solution, stirred, and heated to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0013] The cobalt salt is selected from at least one of cobalt acetate, cobalt bromide, cobalt acetylacetonate, cobalt carbonate, and cobalt chloride;
[0014] The nitrogen-containing compound is selected from at least one of tryptophan, phenylalanine, tyrosine, cobalamin, and 1,4-phenanthroline;
[0015] The nano-metal oxide is at least one of magnesium oxide nanoparticles, magnesium oxide nanospheres, magnesium oxide nanosheets, calcium oxide nanoparticles, nano-hydrotalcite, and nano-hydroxyapatite.
[0016] The organic solvent is selected from at least one of ethanol, methanol, isopropanol, cyclohexanol, and hexafluoroisopropanol.
[0017] The mass ratio of the cobalt salt, nitrogen-containing compound, nano-metal oxide, and organic solvent is 1:1 to 10:0.1 to 20:50 to 100.
[0018] The drying temperature is 40–100°C.
[0019] The drying time is 2 to 24 hours.
[0020] The inactive gas atmosphere is selected from nitrogen atmosphere and / or inert gas atmosphere;
[0021] The pyrolysis temperature is 600–900℃;
[0022] The pyrolysis time is 2 to 6 hours.
[0023] The heating temperature is 40–100°C;
[0024] The heating time is 6 to 12 hours.
[0025] The mass ratio of the transition metal oxide to the nitrogen-doped carbon-supported cobalt-based catalyst is 1:10 to 10:1.
[0026] The oxygen-containing atmosphere is selected from air atmosphere or oxygen atmosphere;
[0027] The solvent is selected from one of N,N-dimethylformamide, acetonitrile, toluene, dioxane, and dichloromethane.
[0028] The reaction temperature is 25–120°C;
[0029] The reaction time is 4–24 hours;
[0030] The reaction pressure is 0.2–1.5 MPa.
[0031] Typical cobalt-based catalyst synthesis method 1: Weigh cobalt acetate and 1,4-o-phenanthroline in a mass ratio of 1:1.5 and place them in a round-bottom flask containing 50 mL of ethanol. Stir vigorously for 30 min, add 0.7 g of magnesium oxide nanoparticles, and mix the support with cobalt acetate and 1,10-o-phenanthroline thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 80 °C for 8 h. Pyrolyze the obtained solid under a nitrogen atmosphere. The temperature program is as follows: from room temperature (25 °C), increase to 800 °C at a rate of 10 °C / min, and hold at this temperature for 2 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 60 °C, stir for 10 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0032] Typical cobalt-based catalyst synthesis method 2: Weigh cobalt bromide and tyrosine in a mass ratio of 1:4 and place them in a round-bottom flask containing 50 mL of ethanol. Stir vigorously for 30 min, add 1 g of magnesium oxide nanoparticles, and mix the support with cobalt bromide and tyrosine thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 100 °C for 12 h. The obtained solid is then pyrolyzed in a nitrogen atmosphere. The temperature program is as follows: from room temperature (25 °C), increase to 900 °C at a rate of 10 °C / min, and hold at this temperature for 2 h. The obtained solid is mixed with sulfuric acid aqueous solution, heated to 40 °C, stirred for 6 h, and dried to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0033] Typical cobalt-based catalyst synthesis method 3: Weigh cobalt acetylacetonate and phenylalanine in a mass ratio of 1:8 and place them in a round-bottom flask containing 50 mL of ethanol. Stir vigorously for 30 min, add 0.5 g of magnesium oxide nanoparticles, and mix the support with cobalt acetylacetonate and phenylalanine thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 40 °C for 24 h. Pyrolyze the obtained solid. The temperature program is as follows: from room temperature (25 °C), increase to 700 °C at a rate of 10 °C / min, and hold at this temperature for 3 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 80 °C, stir for 6 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0034] Typical cobalt-based catalyst synthesis method 4: Weigh cobalt chloride and tryptophan in a mass ratio of 1:20 and place them in a round-bottom flask containing 50 mL of ethanol. Stir vigorously for 30 min, add 0.9 g of magnesium oxide nanoparticles, and mix the support with cobalt chloride and tryptophan thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 60 °C for 14 h. Pyrolyze the obtained solid. The temperature program is as follows: from room temperature (25 °C), increase to 600 °C at a rate of 10 °C / min, and hold at this temperature for 5 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 90 °C, stir for 8 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0035] Typical cobalt-based catalyst synthesis method 5: Weigh cobalt acetate and 1,4-o-phenanthroline in a mass ratio of 1:1.5 and place them in a round-bottom flask containing 50 mL of ethanol. Stir vigorously for 30 min, add 2 g of magnesium oxide nanoparticles, and mix the support with cobalt acetate and 1,10-o-phenanthroline thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 40 °C for 24 h. Pyrolyze the obtained solid under a nitrogen atmosphere. The temperature program is as follows: from room temperature (25 °C), increase to 600 °C at a rate of 10 °C / min, and hold at this temperature for 6 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 100 °C, stir for 6 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0036] Typical cobalt-based catalyst synthesis method 6: Weigh cobalt bromide and tyrosine in a mass ratio of 1:10 and place them in a round-bottom flask containing 50 mL of ethanol. Stir vigorously for 30 min, add 0.9 g of magnesium oxide nanoparticles, and mix the support with cobalt bromide and tyrosine thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 80 °C for 10 h. Pyrolyze the obtained solid under a nitrogen atmosphere. The temperature program is as follows: from room temperature (25 °C), increase to 700 °C at a rate of 10 °C / min, and hold at this temperature for 3 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 60 °C, stir for 4 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0037] Typical cobalt-based catalyst synthesis method 7: Weigh cobalt acetylacetonate and phenylalanine in a mass ratio of 1:10 and place them in a round-bottom flask containing 50 mL of ethanol. Stir vigorously for 30 min, add 1.7 g of magnesium oxide nanosheets, and mix the support with cobalt acetylacetonate and phenylalanine thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 60 °C for 15 h. Pyrolyze the obtained solid. The temperature program is as follows: from room temperature (25 °C), increase to 800 °C at a rate of 10 °C / min, and hold at this temperature for 2 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 90 °C, stir for 8 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0038] Typical cobalt-based catalyst synthesis method 8: Weigh cobalt chloride and tryptophan in a mass ratio of 1:10 and place them in a round-bottom flask containing 70 mL of ethanol. Stir vigorously for 30 min, add 5.7 g of magnesium oxide nanoparticles, and mix the support with cobalt chloride and tryptophan thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 80 °C for 8 h. Pyrolyze the obtained solid. The temperature program is as follows: from room temperature (25 °C), increase to 700 °C at a rate of 10 °C / min, and hold at this temperature for 4 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 70 °C, stir for 12 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0039] Typical cobalt-based catalyst synthesis method 9: Weigh cobalt acetate and 1,10-o-phenanthroline in a mass ratio of 1:2 and place them in a round-bottom flask containing 100 mL of ethanol. Stir vigorously for 30 min, add 10 g of magnesium oxide nanoparticles, and mix the support with cobalt acetate and 1,10-o-phenanthroline thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 60 °C for 12 h. Pyrolyze the obtained solid under a nitrogen atmosphere. The temperature program is as follows: from room temperature (25 °C), increase to 900 °C at a rate of 10 °C / min, and hold at this temperature for 2 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 40 °C, stir for 12 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0040] Typical cobalt-based catalyst synthesis method 10: Weigh cobalt bromide and tyrosine in a mass ratio of 1:8 and place them in a round-bottom flask containing 50 mL of methanol. Stir vigorously for 30 min, add 0.7 g of magnesium oxide nanoparticles, and mix the support with cobalt bromide and tyrosine thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent, and then dry at 70 °C for 24 h. Pyrolyze the obtained solid under a nitrogen atmosphere. The temperature program is as follows: from room temperature (25 °C), increase to 700 °C at a rate of 10 °C / min, and hold at this temperature for 4 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 80 °C, stir for 12 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0041] Typical cobalt-based catalyst synthesis method 11: Weigh cobalt acetylacetonate and phenylalanine in a mass ratio of 1:7 and place them in a round-bottom flask containing 50 mL of ethanol. Stir vigorously for 30 min, add 1 g of nano-hydrotalcite, and mix the support with cobalt acetylacetonate and phenylalanine thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 60 °C for 18 h. Pyrolyze the obtained solid. The temperature program is as follows: from room temperature (25 °C), increase to 600 °C at a rate of 10 °C / min, and hold at this temperature for 6 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 90 °C, stir for 8 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0042] Typical cobalt-based catalyst synthesis method 12: Weigh cobalt chloride and tryptophan in a mass ratio of 1:4 and place them in a round-bottom flask containing 50 mL of ethanol. Stir vigorously for 30 min, add 0.8 g of nano-hydroxyapatite, and mix the support with cobalt chloride and tryptophan thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent ethanol, and then dry at 100 °C for 6 h. Pyrolyze the obtained solid. The temperature program is as follows: from room temperature (25 °C), increase to 800 °C at a rate of 10 °C / min, and hold at this temperature for 2 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 80 °C, stir for 12 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0043] Typical cobalt-based catalyst synthesis method 13: Weigh cobalt acetate and 1,4-o-phenanthroline in a mass ratio of 1:1.5 and place them in a round-bottom flask containing 50 mL of isopropanol. Stir vigorously for 30 min, add 0.7 g of magnesium oxide nanospheres, and mix the support with cobalt acetate and 1,10-o-phenanthroline thoroughly to ensure that the cobalt complex is adsorbed onto the support as much as possible. Remove the solvent, and then dry at 80 °C for 8 h. Pyrolyze the obtained solid under a nitrogen atmosphere. The temperature program is as follows: from room temperature (25 °C), increase to 800 °C at a rate of 10 °C / min, and hold at this temperature for 2 h. Mix the obtained solid with sulfuric acid aqueous solution, heat to 60 °C, stir for 10 h, and dry to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
[0044] Compared with existing reports, this synthetic method has the following advantages:
[0045] (1) The method for preparing ketone compounds by catalytic oxidation of aromatic hydrocarbons provided in this application selectively obtains the corresponding ketone compounds under an oxygen-containing atmosphere using a non-precious metal catalyst.
[0046] (2) The method of this application enables the oxidation of aromatic hydrocarbons to prepare ketone compounds under relatively mild conditions, thus optimizing the synthesis method;
[0047] (3) The method of this application improves the efficiency of catalytic reaction by mixing transition metal oxides and cobalt-based catalysts to form a composite bimetallic catalyst.
[0048] (4) In this application, a heterogeneous catalyst is used, which avoids the subsequent complex separation operation, reduces production costs, and also reduces environmental pollution.
[0049] (5) It has a certain degree of universality. Applying this catalyst to the selective oxidation of various aromatic hydrocarbons expands the applicable range of the catalyst and provides new ideas for oxidation reactions. Detailed Implementation
[0050] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0051] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0052] In the embodiments of this application, the conversion rate of aromatic hydrocarbons and the selectivity of the corresponding ketones are calculated based on the conservation of moles:
[0053] Reactant conversion rate = (1 - (moles of reactant remaining after reaction) / (total moles of reactant)) × 100%
[0054] Example 1
[0055] Selective oxidation of fluorene: 0.0332 g of fluorene, 0.01 g of MnO2, 0.015 g of cobalt-based catalyst and 2 mL of N,N-dimethylformamide were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 0.8 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0056] Example 2
[0057] Selective oxidation of 3,6-dimethoxyfluorene: 0.0452 g of 3,6-dimethoxyfluorene, 0.02 g of V₂O₅, 0.03 g of cobalt-based catalyst, and 2 mL of N,N-dimethylformamide were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 1 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0058] Example 3
[0059] Selective oxidation of 2-phenyl-1-acetophenone: 0.0392 g of 2-phenyl-1-acetophenone, 0.02 g of Ni₂O₃, 0.03 g of cobalt-based catalyst, and 2 mL of N,N-dimethylformamide were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 1.1 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0060] Example 4
[0061] Selective oxidation of anthrone: 0.0388 g of anthrone, 0.01 g of CuO, 0.015 g of cobalt-based catalyst and 2 mL of N,N-dimethylformamide were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 1 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0062] Example 5
[0063] Selective oxidation of 9,10-dihydroanthracene: 0.0360 g of 9,10-dihydroanthracene, 0.01 g of Fe3O4, 0.01 g of cobalt-based catalyst, and 2 mL of N,N-dimethylformamide were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 1 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0064] Example 6
[0065] Selective oxidation of xanthracene: 0.0364 g of xanthracene, 0.01 g of MnO2, 0.015 g of cobalt-based catalyst and 2 mL of N,N-dimethylformamide were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 1.2 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0066] Example 7
[0067] Selective oxidation reaction of thioxanthracene: 0.0396 g of thioxanthracene, 0.01 g of MnO2, 0.015 g of cobalt-based catalyst and 2 mL of N,N-dimethylformamide were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 1 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0068] Example 8
[0069] Selective oxidation of ethylbenzene: 0.0212 g of ethylbenzene, 0.01 g of MnO2, 0.015 g of cobalt-based catalyst and 2 mL of N,N-dimethylformamide were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 80 °C in 11 min, and oxygen was introduced to 1.5 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0070] Example 9
[0071] Selective oxidation reaction of tetrahydronaphthalene: 0.0264 g of tetrahydronaphthalene, 0.01 g of MnO2, 0.015 g of cobalt-based catalyst and 2 mL of N,N-dimethylformamide were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside the reactor was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 80 °C in 11 min, and oxygen was added to 0.4 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0072] Example 10
[0073] Selective oxidation of fluorene: 0.0332 g of fluorene, 0.010 g of MnO2, 0.050 g of cobalt-based catalyst and 2 mL of N,N-dimethylformamide were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 1 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0074] Example 11
[0075] Selective oxidation of fluorene: 0.0332 g of fluorene, 0.01 g of MnO2, 0.015 g of cobalt-based catalyst and 2 mL of acetonitrile were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 0.3 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0076] Example 12
[0077] Selective oxidation of fluorene: 0.0332 g of fluorene, 0.01 g of MnO2, 0.015 g of cobalt-based catalyst and 2 mL of toluene were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 1 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0078] Example 13
[0079] Selective oxidation of fluorene: 0.0332 g of fluorene, 0.01 g of MnO2, 0.015 g of cobalt-based catalyst and 2 mL of dioxane were placed in a high-pressure reactor lined with polytetrafluoroethylene. The reactor was sealed, and the air inside was replaced with oxygen three times to ensure the purity of the gas inside the reactor. Then, the temperature was increased from 25 °C to 100 °C in 15 min, and oxygen was introduced to 1 MPa. The reaction was carried out for 6 h. After the reaction was completed, the reaction results were analyzed by liquid chromatography.
[0080] Table 1 shows the selective oxidation performance of aromatic hydrocarbons in some examples.
[0081]
[0082]
[0083] 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 aromatic ketone compounds from aromatic compounds, characterized in that, Includes the following steps: In a reactor under an oxygen-containing atmosphere, a solvent, an aromatic compound, a transition metal oxide, and a nitrogen-doped carbon-supported cobalt-based catalyst are mixed and reacted to obtain aromatic ketone compounds. The substance is selected from at least one of fluorene, tetrahydronaphthalene, ethylbenzene, 3,6-dimethoxyfluorene, diphenylmethane, 2-phenyl-1-acetophenone, anthrone, 9,10-dihydroanthracene, oxanthracene, and thioxanthracene; The transition metal oxide is selected from at least one of MnO2, Fe3O4, CuO, Ni2O3, and V2O5; In the nitrogen-doped carbon-supported cobalt-based catalyst, the mass content of cobalt is 1-wt%.
2. The method according to claim 1, characterized in that, The nitrogen-doped carbon-supported cobalt-based catalyst is obtained through the following steps: Cobalt salt, nitrogen-containing compound, nano-metal oxide, and organic solvent are mixed, dried, pyrolyzed under an inactive gas atmosphere, mixed with sulfuric acid aqueous solution, stirred, and heated to obtain the nitrogen-doped carbon-supported cobalt-based catalyst.
3. The method according to claim 2, characterized in that, The cobalt salt is selected from at least one of cobalt acetate, cobalt bromide, cobalt acetylacetonate, cobalt carbonate, and cobalt chloride; The nitrogen-containing compound is selected from at least one of tryptophan, phenylalanine, tyrosine, cobalamin, and 1,4-phenanthroline; The nano-metal oxide is at least one of magnesium oxide nanoparticles, magnesium oxide nanospheres, magnesium oxide nanosheets, calcium oxide nanoparticles, nano-hydrotalcite, and nano-hydroxyapatite. The organic solvent is selected from at least one of ethanol, methanol, isopropanol, cyclohexanol, and hexafluoroisopropanol.
4. The method according to claim 2, characterized in that, The mass ratio of the cobalt salt, nitrogen-containing compound, nano-metal oxide, and organic solvent is 1:1 to 10:0.1 to 20:50 to 100.
5. The method according to claim 2, characterized in that, The drying temperature is 40–100°C. The drying time is 2 to 24 hours.
6. The method according to claim 2, characterized in that, The inactive gas atmosphere is selected from nitrogen atmosphere and / or inert gas atmosphere; The pyrolysis temperature is 600–900℃; The pyrolysis time is 2 to 6 hours.
7. The method according to claim 2, characterized in that, The heating temperature is 40–100°C; The heating time is 6 to 12 hours.
8. The method according to claim 1, characterized in that, The mass ratio of the transition metal oxide to the nitrogen-doped carbon-supported cobalt-based catalyst is 1:10 to 10:
1.
9. The method according to claim 1, characterized in that, The oxygen-containing atmosphere is selected from air atmosphere or oxygen atmosphere; The solvent is selected from one of N,N-dimethylformamide, acetonitrile, toluene, dioxane, and dichloromethane.
10. The method according to claim 1, characterized in that, The reaction temperature is 25–120°C; The reaction time is 4–24 hours; The reaction pressure is 0.2–1.5 MPa.