Catalytic system and method for selective catalytic oxidation of aromatic hydrocarbons
By using a metal-free catalytic system composed of organic nitrogen hydroxy compounds and surfactants, the problems of low reaction efficiency during selective catalytic oxidation of aromatic hydrocarbons in the prior art, the ease of deactivation of precious metal catalysts and the difficulty in suppressing by-product generation are solved, and the catalytic oxidation effect with high efficiency, low energy consumption and environmental protection are achieved.
Patent Information
- Application Number
- CN202510205559.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2025-06-13
AI Technical Summary
In the selective catalytic oxidation of aromatic hydrocarbons, the conflicts between reaction kinetics and thermodynamics, the prone to inactivation of precious metal catalysts, and the difficulty in suppressing the generation of deep oxidation by-products, resulting in low reaction efficiency, high cost and serious environmental pollution.
A metal-free catalytic system consisting of organic oxyhydride compounds and surfactant nonylphenol polyoxyethylene ether or polyethylene glycol is used to improve catalytic activity and reduce by-product generation through hydrogen bonding between the catalyst and the catalyst additive.
It realizes efficient catalytic aromatic oxidation under mild conditions, significantly improving aromatic conversion and oxidation product selectivity, reducing reaction temperature and energy consumption, and reducing by-product generation.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of hydrocarbon catalytic oxidation, and particularly relates to a catalytic system and method for selective catalytic oxidation of aromatic hydrocarbons. Background Art
[0002] As one of the core technologies for efficient utilization of carbon resources in modern chemical industry, selective catalytic oxidation of hydrocarbons has an irreplaceable strategic position in the field of synthesizing high-value oxygen-containing chemicals. According to statistics, about 30% of global chemical product production involves catalytic oxidation processes. Especially in the synthesis of pharmaceutical intermediates, polymer monomers and fine chemicals, this technology realizes the green preparation of important basic chemicals such as alcohols, ketones, and carboxylic acids through the directional activation of C-H bonds.
[0003] However, there are still three key technical bottlenecks in existing industrial catalytic systems: First, the contradiction between reaction kinetics and thermodynamics is prominent. Taking the liquid-phase oxidation of cumene to cumene hydroperoxide as an example, to maintain a selectivity of more than 85%, the conversion rate is limited to less than 25%, resulting in the energy consumption of the reaction-separation cycle accounting for 40% of the total process cost; Second, noble metal catalysts (such as Pt / Al 2 O 3 ) are prone to sintering inactivation at high temperatures (>200°C). The service life of the catalyst in a certain acrylic acid production plant of an enterprise is only 800 - 1000 hours, and the annual replacement cost exceeds tens of millions; Third, it is difficult to suppress the formation of deep oxidation by-products (such as CO x ). In a 200,000-ton / year adipic acid plant, the by-product of N 2 O reaches 42,000 tons / year, which is equivalent to 550,000 tons of CO 2 equivalent greenhouse effect. Although some technologies have been improved in recent years through means such as microreactor design and bifunctional catalyst development, traditional processes still have significant defects in terms of atom economy (generally lower than 65%), process safety (oxidation reaction runaway risk index > 3), and environmental friendliness (wastewater COD value > 5000 mg / L).
[0004] Therefore, developing a new catalytic system with high intrinsic activity, excellent shape selectivity and stability, and constructing an efficient oxidation process under low-temperature and low-pressure conditions have become the key to breaking through the industry's technical barriers and achieving the goal of carbon neutrality. Summary of the Invention
[0005] The present invention provides a catalytic system for selective catalytic oxidation of aromatic hydrocarbons, which has both high catalytic activity and high selectivity for oxidation products, and can catalyze the oxidation reaction of aromatic hydrocarbons under mild conditions to achieve high catalytic activity and high selectivity for oxidation products.
[0006] The technical solution of the present invention is: a system for the selective catalytic oxidation of aromatic hydrocarbons, which consists of a catalyst and a catalytic assistant. The catalyst is an organic nitrogen hydroxy compound, and the catalytic assistant is nonylphenol polyoxyethylene ether or polyethylene glycol.
[0007] The catalyst includes but is not limited to N-hydroxyphthalimide and its derivatives, such as N-hydroxy-3,4,5,6-tetrachlorophthalimide, N-hydroxy-1,8-naphthalimide, etc.
[0008] Preferably, the molar ratio of the catalyst to the aromatic hydrocarbon is 1:20 - 1:5, and more preferably 1:15 - 1:8.
[0009] Preferably, the molar ratio of the catalytic assistant to the aromatic hydrocarbon is 1:20 - 1:5, and more preferably 1:15 - 1:8.
[0010] The aromatic hydrocarbons include but are not limited to one or several compounds among toluene, ethylbenzene, fluorene, indene, or derivatives of these compounds. The derivatives are compounds substituted with one or several of halogen, alkyl, alkoxy, etc., such as p-xylene, p-chlorotoluene, p-ethyltoluene, etc.
[0011] The nonylphenol polyoxyethylene ether includes but is not limited to one or several of NP-7, NP-9, NP-10.
[0012] The polyethylene glycol includes but is not limited to one or several of PEG1000, PEG2000, PEG4000.
[0013] In the reaction system for the selective catalytic oxidation of aromatic hydrocarbons, it is preferred to use oxygen as the oxidant, and the pressure of oxygen is preferably 0.3 MPa - 1.1 MPa.
[0014] In the reaction system for the selective catalytic oxidation of aromatic hydrocarbons, the reaction temperature is preferably lower than 100 °C, such as 70 °C - 90 °C, more preferably 75 °C - 85 °C, and even more preferably 80 ± 2 °C.
[0015] In the reaction system for the selective catalytic oxidation of aromatic hydrocarbons, the reaction time is preferably 5 h - 24 h, and more preferably 7 h - 10 h.
[0016] The present invention also provides a method for the selective catalytic oxidation of aromatic hydrocarbons, wherein the aromatic hydrocarbon, an organic solvent, and the catalyst system are placed in a reaction kettle, and oxygen is introduced to carry out the selective catalytic oxidation reaction of the aromatic hydrocarbon.
[0017] Preferably, the material of the reaction kettle is a material with high temperature resistance and high pressure resistance, such as stainless steel, to ensure the stability and safety of the reaction system. As a further preference, its inner lining is polytetrafluoroethylene.
[0018] Preferably, the reactor is equipped with a temperature controller, which can accurately control and monitor the temperature of the reaction system to ensure that the reaction proceeds within the set temperature range. As a further preference, before the reaction starts, the reaction materials are added into the reactor, and the reactor is sealed. Then the temperature controller is started, and the initial heating rate is set to heat the reaction system to the set reaction temperature. When the reaction system reaches the set reaction temperature, the temperature controller automatically switches to the constant temperature mode to keep the temperature of the reaction system stable at the set reaction temperature for a certain period of reaction. Preferably, the heating rate is controlled so that the reaction system is heated to the set reaction temperature within 10 min - 15 min. Preferably, after the temperature of the reaction system is stable at the set reaction temperature, the reaction continues for 5 h - 24 h.
[0019] After the reaction is completed, the temperature of the reaction system is cooled to room temperature, and the reaction product is taken out for subsequent separation and analysis operations. Preferably, after the reaction is completed, the heating device is turned off, and the reactor is placed in an ice - water bath to cool the reaction system to room temperature. During the cooling process, circulating ventilation can be assisted to accelerate heat dissipation to ensure the safe cooling of the reaction system to room temperature. After cooling is completed, the reactor is opened, and the reaction product is taken out for subsequent separation and analysis operations.
[0020] In the present invention, the internal standard method is used to detect the reaction product to obtain the conversion rate of aromatic hydrocarbons and the selectivity of the oxidation product. The definitions of the conversion rate of aromatic hydrocarbons and the selectivity of the oxidation product are as follows:
[0021]
[0022] Compared with the prior art, the present invention has the following beneficial effects:
[0023] (1) In the selective catalytic oxidation of aromatic hydrocarbon compounds to prepare oxygen - containing compounds in the present invention, a metal - free catalytic system is composed of an organic nitrogen - hydroxyl compound and a surfactant nonylphenol polyoxyethylene ether or polyethylene glycol. There is a hydrogen - bond interaction between the surfactant and the organic nitrogen - hydroxyl compound, which can improve the catalytic activity, significantly improve the reaction efficiency and reduce the generation of by - products, realizing high conversion rate of aromatic hydrocarbons and high selectivity of oxidation products.
[0024] (2) When the selective catalytic oxidation of aromatic hydrocarbon compounds is carried out using the catalytic system of the present invention, the reaction temperature can be reduced. For example, when the reaction occurs in a reactor, high conversion rate of aromatic hydrocarbons and high selectivity of oxides can be achieved under the condition of less than 100 °C.
[0025] For example, during the catalytic oxidation of ethylbenzene, under the conditions of an oxygen pressure of 1 MPa, a reaction temperature of 80 °C, and a reaction time of 5 h or more (including 5 h), the conversion rate of ethylbenzene can be higher than 40%, and the selectivity for acetophenone can be higher than 30%; even the conversion rate of ethylbenzene can be higher than 40%, and the selectivity for acetophenone can be higher than 40%; even more, the conversion rate of ethylbenzene can be higher than 70%, and the selectivity for acetophenone can be higher than 70%.
[0026] During the catalytic oxidation of ethylbenzene, under the conditions of an oxygen pressure of 1 MPa, a reaction temperature of 80 °C, and a reaction time of 9 h or more (including 9 h), the conversion rate of ethylbenzene can be higher than 80%, and the selectivity for acetophenone can be higher than 80%.
[0027] During the catalytic oxidation of toluene, under the conditions of an oxygen pressure of 1 MPa, a reaction temperature of 80 °C, and a reaction time of 5 h or more (including 5 h), the conversion rate of toluene can be higher than 40%, and the selectivity for benzoic acid can be higher than 70%.
[0028] During the catalytic oxidation of toluene, under the conditions of an oxygen pressure of 1 MPa, a reaction temperature of 80 °C, and a reaction time of 9 h or more (including 9 h), the conversion rate of toluene can be higher than 50%, and the selectivity for benzoic acid can be higher than 80%; even the conversion rate of toluene can be higher than 70%, and the selectivity for benzoic acid can be higher than 80%.
[0029] During the catalytic oxidation of fluorene, under the conditions of an oxygen pressure of 1 MPa, a reaction temperature of 80 °C, and a reaction time of 9 h or more (including 9 h), the conversion rate of fluorene can be higher than 90%, and the selectivity for fluorenone can be higher than 90%.
[0030] During the catalytic oxidation of indene, under the conditions of an oxygen pressure of 1 MPa, a reaction temperature of 80 °C, and a reaction time of 9 h or more (including 9 h), the conversion rate of indene can be higher than 90%, and the selectivity for indanone can be higher than 90%.
[0031] (3) The present invention can regulate the conversion rate of aromatic hydrocarbons and the selectivity of oxidation products by controlling one or several of the catalyst, catalytic promoter, oxygen pressure, reaction temperature, and reaction time, and can take into account low cost, mild reaction conditions, high catalytic activity, and high selectivity, and has broad application prospects in the fields of chemical synthesis, environmental protection, and energy conversion, etc. Detailed implementation manners
[0032] The present invention will be further described in detail below in conjunction with the embodiments. It should be noted that the following embodiments are intended to facilitate the understanding of the present invention, and any non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention above still fall within the protection scope of the present invention.
[0033] In the present invention, words such as "including" and "comprising" should be construed to have an inclusive meaning rather than an exclusive or exhaustive meaning; that is, it is the meaning of "including but not limited to".
[0034] Comparative Example 1:
[0035] In the catalytic oxidation reaction of ethylbenzene, the catalyst is N-hydroxyphthalimide, and the molar amount of the catalyst is 10% of the molar amount of ethylbenzene.
[0036] This reaction is carried out in a traditional stainless steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0037] Add 2 mmol of ethylbenzene, 0.2 mmol of N-hydroxyphthalimide, and 4 mL of acetonitrile into the reactor, seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the temperature of the reaction system to remain at 80 °C for 5 h;
[0038] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and use the internal standard method to detect the reaction product. The conversion rate of ethylbenzene is 27% and the selectivity of acetophenone is 28%.
[0039] Example 1-1:
[0040] In the catalytic oxidation reaction of ethylbenzene, a catalytic system is used to catalyze this reaction. The catalytic system consists of a catalyst and a catalytic assistant. The catalyst is N-hydroxyphthalimide, and the catalytic assistant is PEG1000. The molar amount of the catalyst is 10% of the molar amount of ethylbenzene, and the molar amount of the catalytic assistant is 10% of the molar amount of ethylbenzene.
[0041] This reaction is carried out in a traditional stainless steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0042] Add 2 mmol of ethylbenzene, 0.2 mmol of N-hydroxyphthalimide, 0.2 mmol of PEG1000, and 4 mL of acetonitrile into the reactor, seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the temperature of the reaction system to remain at 80 °C for 5 h;
[0043] After the reaction is completed, place the reaction kettle in an ice-water bath, cool the reaction system to room temperature, then open the reaction kettle, take out the reaction product, and use the internal standard method to detect the reaction product. The conversion rate of ethylbenzene is 49%, and the selectivity of acetophenone is 34%.
[0044] Example 1-2:
[0045] This example is basically the same as Example 1-1, except that PEG2000 is used instead of PEG1000 in Example 1-1 as the catalytic assistant in the catalytic oxidation reaction of ethylbenzene.
[0046] In this example, the reaction method is basically the same as that in Example 1-1, except that PEG2000 is used instead of PEG1000 in Example 1-1 as the catalytic assistant in the catalytic oxidation reaction of ethylbenzene. The conversion rate of ethylbenzene measured after the reaction is completed is 77%, and the selectivity of acetophenone is 80%.
[0047] Example 1-3:
[0048] This example is basically the same as Example 1-1, except that PEG4000 is used instead of PEG1000 in Example 1-1 as the catalytic assistant in the catalytic oxidation reaction of ethylbenzene.
[0049] In this example, the reaction method is basically the same as that in Example 1-1, except that PEG4000 is used instead of PEG1000 in Example 1-1 as the catalytic assistant in the catalytic oxidation reaction of ethylbenzene. The conversion rate of ethylbenzene measured after the reaction is completed is 45%, and the selectivity of acetophenone is 48%.
[0050] Example 1-4:
[0051] This example is basically the same as Example 1-1, except that NP-9 is used instead of PEG1000 in Example 1-1 as the catalytic assistant in the catalytic oxidation reaction of ethylbenzene.
[0052] In this example, the reaction method is basically the same as that in Example 1-1, except that NP-9 is used instead of PEG1000 in Example 1-1 as the catalytic assistant in the catalytic oxidation reaction of ethylbenzene. The conversion rate of ethylbenzene measured after the reaction is completed is 43%, and the selectivity of acetophenone is 32%.
[0053] Example 1-5:
[0054] This example is basically the same as Example 1-1, except that NP-10 is used instead of PEG1000 in Example 1-1 as the catalytic assistant in the catalytic oxidation reaction of ethylbenzene.
[0055] In this example, the reaction method is basically the same as that in Example 1-1. The difference is that NP-10 is used instead of PEG1000 in Example 1-1 as the catalytic assistant in the catalytic oxidation reaction of ethylbenzene. The conversion rate of ethylbenzene measured after the reaction is completed is 45%, and the selectivity of acetophenone is 41%.
[0056] Example 1-2-1:
[0057] This example is basically the same as Example 1-2-1. The difference is that in the reaction method, when the temperature of the reaction system reaches 70 °C, the temperature controller automatically switches to the constant temperature mode, and the temperature of the reaction system is controlled to remain at 70 °C for 5 h. The conversion rate of ethylbenzene measured after the reaction is completed is 46%, and the selectivity of acetophenone is 43%.
[0058] Example 1-2-2:
[0059] This example is basically the same as Example 1-2-1. The difference is that in the reaction method, when the temperature of the reaction system reaches 90 °C, the temperature controller automatically switches to the constant temperature mode, and the temperature of the reaction system is controlled to remain at 90 °C for 5 h. The conversion rate of ethylbenzene measured after the reaction is completed is 79%, and the selectivity of acetophenone is 78%.
[0060] Example 1-2-3:
[0061] This example is basically the same as Example 1-2-1. The difference is that in the reaction method, when the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and the temperature of the reaction system is controlled to remain at 80 °C for 9 h. The conversion rate of ethylbenzene measured after the reaction is completed is 85%, and the selectivity of acetophenone is 83%.
[0062] Example 1-2-4:
[0063] This example is basically the same as Example 1-2-1. The difference is that in the reaction method, when the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and the temperature of the reaction system is controlled to remain at 80 °C for 24 h. The conversion rate of ethylbenzene measured after the reaction is completed is 94%, and the selectivity of acetophenone is 90%.
[0064] Comparative Example 2:
[0065] In the catalytic oxidation reaction of ethylbenzene, the catalyst is N-hydroxy-3,4,5,6-tetrachlorophthalimide, and the molar amount of the catalyst is 10% of the molar amount of ethylbenzene.
[0066] This reaction is carried out in a traditional stainless steel reactor. The inner lining of the reactor is polytetrafluoroethylene, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0067] Add 2 mmol of ethylbenzene, 0.2 mmol of N-hydroxy-3,4,5,6-tetrachlorophthalimide, and 4 mL of acetonitrile to a reaction kettle. Seal the reaction kettle and introduce oxygen to make the oxygen pressure in the reaction kettle 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 5 h;
[0068] After the reaction is completed, place the reaction kettle in an ice-water bath, cool the reaction system to room temperature, then open the reaction kettle, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of ethylbenzene is 19%, and the selectivity of acetophenone is 31%.
[0069] Example 2:
[0070] In the catalytic oxidation reaction of ethylbenzene, use a catalytic system to catalyze this reaction. The catalytic system consists of a catalyst and a catalytic assistant. The catalyst is N-hydroxy-3,4,5,6-tetrachlorophthalimide, and the catalytic assistant is PEG2000. And the molar amount of the catalyst is 10% of the molar amount of ethylbenzene, and the molar amount of the catalytic assistant is 10% of the molar amount of ethylbenzene.
[0071] This reaction is carried out in a traditional stainless steel reaction kettle. The inner lining of the reaction kettle is polytetrafluoroethylene, and the reaction kettle is equipped with a temperature controller. The reaction process is as follows:
[0072] Add 2 mmol of ethylbenzene, 0.2 mmol of N-hydroxy-3,4,5,6-tetrachlorophthalimide, 0.2 mmol of PEG2000, and 4 mL of acetonitrile to a reaction kettle. Seal the reaction kettle and introduce oxygen to make the oxygen pressure in the reaction kettle 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 5 h;
[0073] After the reaction is completed, place the reaction kettle in an ice-water bath, cool the reaction system to room temperature, then open the reaction kettle, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of ethylbenzene is 54%, and the selectivity of acetophenone is 67%.
[0074] Comparative Example 3:
[0075] In the catalytic oxidation reaction of ethylbenzene, the catalyst is N-hydroxy-1,8-naphthalenedicarboximide, and the molar amount of the catalyst is 10% of the molar amount of ethylbenzene.
[0076] This reaction is carried out in a traditional stainless steel reaction kettle. The inner lining of the reaction kettle is polytetrafluoroethylene, and the reaction kettle is equipped with a temperature controller. The reaction process is as follows:
[0077] Add 2 mmol of ethylbenzene, 0.2 mmol of N-hydroxy-1,8-naphthalenedicarboximide, and 4 mL of acetonitrile to a reaction kettle. Seal the reaction kettle and introduce oxygen to make the oxygen pressure in the reaction kettle 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 5 h;
[0078] After the reaction is completed, place the reaction kettle in an ice-water bath, cool the reaction system to room temperature, then open the reaction kettle, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of ethylbenzene is 12%, and the selectivity of acetophenone is 24%.
[0079] Example 3:
[0080] In the catalytic oxidation reaction of ethylbenzene, use a catalytic system to catalyze this reaction. The catalytic system consists of a catalyst and a catalytic assistant. The catalyst is N-hydroxy-1,8-naphthalenedicarboximide, and the catalytic assistant is PEG2000. And the molar amount of the catalyst is 10% of the molar amount of ethylbenzene, and the molar amount of the catalytic assistant is 10% of the molar amount of ethylbenzene.
[0081] This reaction is carried out in a traditional stainless steel reaction kettle with a polytetrafluoroethylene lining, and the reaction kettle is equipped with a temperature controller. The reaction process is as follows:
[0082] Add 2 mmol of ethylbenzene, 0.2 mmol of N-hydroxy-1,8-naphthalenedicarboximide, 0.2 mmol of PEG2000, and 4 mL of acetonitrile to the reaction kettle. Seal the reaction kettle and introduce oxygen to make the oxygen pressure in the reaction kettle 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 5 h;
[0083] After the reaction is completed, place the reaction kettle in an ice-water bath, cool the reaction system to room temperature, then open the reaction kettle, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of ethylbenzene is 32%, and the selectivity of acetophenone is 35%.
[0084] Comparative Example 4:
[0085] In the catalytic oxidation reaction of toluene, the catalyst is N-hydroxyphthalimide, and the molar amount of the catalyst is 10% of the molar amount of toluene.
[0086] This reaction is carried out in a traditional stainless steel reaction kettle with a polytetrafluoroethylene lining, and the reaction kettle is equipped with a temperature controller. The reaction process is as follows:
[0087] Add 2 mmol of toluene, 0.2 mmol of N-hydroxyphthalimide, and 4 mL of acetonitrile to a reaction kettle. Seal the reaction kettle and introduce oxygen to make the oxygen pressure in the reaction kettle 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 5 h;
[0088] After the reaction is completed, place the reaction kettle in an ice-water bath, cool the reaction system to room temperature, then open the reaction kettle, take out the reaction product, and detect the reaction product by the internal standard method. The toluene conversion rate is 22%, and the benzoic acid selectivity is 48%.
[0089] Example 4-1:
[0090] In the catalytic oxidation reaction of toluene, use a catalytic system to catalyze this reaction. The catalytic system consists of a catalyst and a catalytic promoter. The catalyst is N-hydroxyphthalimide, and the catalytic promoter is PEG2000. And the molar amount of the catalyst is 10% of the molar amount of toluene, and the molar amount of the catalytic promoter is 10% of the molar amount of toluene.
[0091] This reaction is carried out in a traditional stainless steel reaction kettle. The inner lining of the reaction kettle is polytetrafluoroethylene, and the reaction kettle is equipped with a temperature controller. The reaction process is as follows:
[0092] Add 2 mmol of toluene, 0.2 mmol of N-hydroxyphthalimide, 0.2 mmol of PEG2000, and 4 mL of acetonitrile to a reaction kettle. Seal the reaction kettle and introduce oxygen to make the oxygen pressure in the reaction kettle 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 5 h;
[0093] After the reaction is completed, place the reaction kettle in an ice-water bath, cool the reaction system to room temperature, then open the reaction kettle, take out the reaction product, and detect the reaction product by the internal standard method. The toluene conversion rate is 44%, and the benzoic acid selectivity is 75%.
[0094] Example 4-2:
[0095] This example is basically the same as Example 4-1. The difference is that in the reaction method, when the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 9 h. The toluene conversion rate measured after the reaction is completed is 56%, and the benzophenone selectivity is 81%.
[0096] Comparative Example 5:
[0097] In the catalytic oxidation reaction of p-xylene, the catalyst is N-hydroxyphthalimide, and the molar amount of the catalyst is 10% of the molar amount of p-xylene.
[0098] This reaction is carried out in a traditional stainless-steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0099] Add 2 mmol of p-xylene, 0.2 mmol of N-hydroxyphthalimide, and 4 mL of acetonitrile into the reactor, seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 9 h;
[0100] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and use the internal standard method to detect the reaction product. The conversion rate of p-xylene is 30%, and the selectivity of p-methylbenzoic acid is 39%.
[0101] Example 5:
[0102] In the catalytic oxidation reaction of p-xylene, a catalytic system is used to catalyze this reaction. The catalytic system consists of a catalyst and a catalytic promoter. The catalyst is N-hydroxyphthalimide, and the catalytic promoter is PEG2000. The molar amount of the catalyst is 10% of the molar amount of p-xylene, and the molar amount of the catalytic promoter is 10% of the molar amount of p-xylene.
[0103] This reaction is carried out in a traditional stainless-steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0104] Add 2 mmol of p-xylene, 0.2 mmol of N-hydroxyphthalimide, 0.2 mmol of PEG2000, and 4 mL of acetonitrile into the reactor, seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 9 h;
[0105] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and use the internal standard method to detect the reaction product. The conversion rate of p-xylene is 76%, and the selectivity of p-methylbenzoic acid is 88%.
[0106] Comparative Example 6:
[0107] In the catalytic oxidation reaction of p-ethyltoluene, the catalyst is N-hydroxyphthalimide, and the molar amount of the catalyst is 10% of the molar amount of p-ethyltoluene.
[0108] This reaction is carried out in a traditional stainless-steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0109] Add 2 mmol of p-ethyltoluene, 0.2 mmol of N-hydroxyphthalimide, and 4 mL of acetonitrile into the reactor, seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the temperature of the reaction system to remain at 80 °C for 9 h;
[0110] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of p-ethyltoluene is 32%, and the selectivity of p-methylacetophenone is 48%.
[0111] Example 6:
[0112] In the catalytic oxidation reaction of p-ethyltoluene, a catalytic system is used to catalyze this reaction. The catalytic system consists of a catalyst and a catalytic assistant. The catalyst is N-hydroxyphthalimide, and the catalytic assistant is PEG2000. The molar amount of the catalyst is 10% of the molar amount of p-ethyltoluene, and the molar amount of the catalytic assistant is 10% of the molar amount of p-ethyltoluene.
[0113] This reaction is carried out in a traditional stainless-steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0114] Add 2 mmol of p-ethyltoluene, 0.2 mmol of N-hydroxyphthalimide, 0.2 mmol of PEG2000, and 4 mL of acetonitrile into the reactor, seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the temperature of the reaction system to remain at 80 °C for 9 h;
[0115] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of p-ethyltoluene is 84%, and the selectivity of p-methylacetophenone is 82%.
[0116] Comparative Example 7:
[0117] In the catalytic oxidation reaction of p-chlorotoluene, the catalyst is N-hydroxyphthalimide, and the molar amount of the catalyst is 10% of the molar amount of p-chlorotoluene.
[0118] This reaction is carried out in a traditional stainless-steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0119] Add 2 mmol of p-chlorotoluene, 0.2 mmol of N-hydroxyphthalimide, and 4 mL of acetonitrile into the reactor, seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 9 h;
[0120] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of p-chlorotoluene is 20%, and the selectivity of p-chlorobenzoic acid is 45%.
[0121] Example 7:
[0122] In the catalytic oxidation reaction of p-chlorotoluene, a catalytic system is used to catalyze this reaction. The catalytic system consists of a catalyst and a catalytic promoter. The catalyst is N-hydroxyphthalimide, and the catalytic promoter is PEG2000. The molar amount of the catalyst is 10% of the molar amount of p-chlorotoluene, and the molar amount of the catalytic promoter is 10% of the molar amount of p-chlorotoluene.
[0123] This reaction is carried out in a traditional stainless-steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0124] Add 2 mmol of p-chlorotoluene, 0.2 mmol of N-hydroxyphthalimide, 0.2 mmol of PEG2000, and 4 mL of acetonitrile into the reactor, seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the reaction system temperature to remain at 80 °C for 9 h;
[0125] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of p-chlorotoluene is 66%, and the selectivity of p-chlorobenzoic acid is 73%.
[0126] Comparative Example 8:
[0127] In the catalytic oxidation reaction of fluorene, the catalyst is N-hydroxyphthalimide, and the molar amount of the catalyst is 10% of the molar amount of fluorene.
[0128] This reaction is carried out in a traditional stainless-steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0129] Add 2 mmol of fluorene, 0.2 mmol of N-hydroxyphthalimide, and 4 mL of acetonitrile into the reactor, seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the temperature of the reaction system to remain at 80 °C for 9 h;
[0130] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of fluorene is 56%, and the selectivity of fluorenone is 78%.
[0131] Example 8:
[0132] In the catalytic oxidation reaction of fluorene, a catalytic system is used to catalyze this reaction. The catalytic system consists of a catalyst and a catalytic assistant. The catalyst is N-hydroxyphthalimide, and the catalytic assistant is PEG2000. The molar amount of the catalyst is 10% of the molar amount of fluorene, and the molar amount of the catalytic assistant is 10% of the molar amount of fluorene.
[0133] This reaction is carried out in a traditional stainless-steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0134] Add 2 mmol of fluorene, 0.2 mmol of N-hydroxyphthalimide, 0.2 mmol of PEG2000, and 4 mL of acetonitrile into the reactor, seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant temperature mode, and control the temperature of the reaction system to remain at 80 °C for 9 h;
[0135] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of fluorene is 94%, and the selectivity of fluorenone is 97%.
[0136] Comparative Example 9:
[0137] In the catalytic oxidation reaction of indene, the catalyst is N-hydroxyphthalimide, and the molar amount of the catalyst is 10% of the molar amount of indene.
[0138] This reaction is carried out in a traditional stainless-steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0139] Add 2 mmol of indene, 0.2 mmol of N-hydroxyphthalimide, and 4 mL of acetonitrile into the reactor. Seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant-temperature mode, and control the temperature of the reaction system to remain at 80 °C for 24 h;
[0140] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of indene is 60%, and the selectivity of indanone is 75%.
[0141] Example 9:
[0142] In the catalytic oxidation reaction of indene, a catalytic system is used to catalyze this reaction. The catalytic system consists of a catalyst and a catalytic assistant. The catalyst is N-hydroxyphthalimide, and the catalytic assistant is PEG2000. And the molar amount of the catalyst is 10% of the molar amount of indene, and the molar amount of the catalytic assistant is 10% of the molar amount of indene.
[0143] This reaction is carried out in a traditional stainless-steel reactor with a polytetrafluoroethylene lining, and the reactor is equipped with a temperature controller. The reaction process is as follows:
[0144] Add 2 mmol of indene, 0.2 mmol of N-hydroxyphthalimide, 0.2 mmol of PEG2000, and 4 mL of acetonitrile into the reactor. Seal the reactor and introduce oxygen to make the oxygen pressure in the reactor 1.0 MPa. Start the temperature controller and heat the reaction system. When the temperature of the reaction system reaches 80 °C, the temperature controller automatically switches to the constant-temperature mode, and control the temperature of the reaction system to remain at 80 °C for 24 h;
[0145] After the reaction is completed, place the reactor in an ice-water bath, cool the reaction system to room temperature, then open the reactor, take out the reaction product, and detect the reaction product by the internal standard method. The conversion rate of indene is 98%, and the selectivity of indanone is 95%.
[0146] In the above examples, the reactants, reaction conditions, and the results of conversion rate and selectivity are shown in Table 1 below.
[0147] Table 1: Reactants, reaction conditions, and the results of conversion rate and selectivity in the above examples
[0148]
[0149]
[0150] The embodiments described above have elaborated on the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, supplements, or substitutions in a similar manner within the principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A catalytic system for selective catalytic oxidation of aromatic hydrocarbons, characterized in that: The catalyst is composed of a catalyst and a catalyst assistant. The catalyst is an organic nitrogen hydroxyl compound, and the catalyst assistant is nonylphenol polyoxyethylene ether or polyethylene glycol.
2. The catalytic system according to claim 1, characterized in that: The catalyst includes N-hydroxyphthalimide and its derivatives; Preferably, the N-hydroxyphthalimide derivative includes one or both of N-hydroxy-3,4,5,6-tetrachlorophthalimide and N-hydroxy-1,8-naphthalimide.
3. The catalytic system according to claim 1, characterized in that: The molar ratio of the catalyst to the aromatic hydrocarbon is 1:20-1:5, preferably 1:15-1:8; Preferably, the molar ratio of the catalyst promoter to the aromatic hydrocarbon is 1:20-1:5, preferably 1:15-1:
8.
4. The catalytic system according to claim 1, characterized in that: The aromatic hydrocarbons include one or more compounds selected from toluene, ethylbenzene, fluorene and indene, or derivatives of these compounds; Preferably, the compound is substituted with one or more of halogen, alkyl, and alkoxy.
5. The catalytic system according to claim 1, characterized in that: The nonylphenol polyoxyethylene ether includes one or more of NP-7, NP-9 and NP-10; Preferably, the polyethylene glycol includes one or more of PEG1000, PEG2000 and PEG4000.
6. The catalytic system according to claim 1, characterized in that: Used in the reaction system of selective catalytic oxidation of aromatic hydrocarbons, with oxygen as the oxidant; Preferably, in the reaction system for selective catalytic oxidation of aromatic hydrocarbons, the reaction temperature is lower than 100°C, more preferably 70°C-90°C, more preferably 75°C-85°C, and most preferably 80±2°C; Preferably, the pressure of oxygen is 0.3MPa-1.1MPa; Preferably, in the reaction system for selective catalytic oxidation of aromatics, the reaction time is 5 h to 24 h, more preferably 7 h to 10 h.
7. A method for selective catalytic oxidation of aromatic hydrocarbons, characterized in that: Aromatic hydrocarbons, an organic solvent, and the catalytic system described in any one of claims 1 to 6 are placed in a reaction kettle, and oxygen is introduced to carry out a selective catalytic oxidation reaction of the aromatic hydrocarbons.
8. The method for selective catalytic oxidation of aromatics as claimed in claim 8, characterized in that: The reactor is equipped with a temperature controller; Preferably, before the reaction starts, the reaction materials are added to the reactor, and the reactor is sealed, and the temperature controller is started to heat the reaction system to the set reaction temperature. When the reaction system reaches the set reaction temperature, the temperature controller automatically switches to the constant temperature mode to keep the temperature of the reaction system stable at the set reaction temperature for a certain period of time; Preferably, the heating rate is controlled so that the reaction system is heated to the set reaction temperature within 10 min-15 min; Preferably, the reaction system temperature stabilizes at the set reaction temperature and the reaction continues for 5h-24h.
9. The method for selective catalytic oxidation of aromatic hydrocarbons as claimed in claim 1, characterized in that: During the catalytic oxidation of ethylbenzene, under the conditions of an oxygen pressure of 1 MPa and a reaction temperature of 80° C. for more than 5 hours: the conversion rate of ethylbenzene is higher than 40%, and the selectivity of acetophenone is higher than 30%; preferably, the conversion rate of ethylbenzene is higher than 40%, and the selectivity of acetophenone is higher than 40%; more preferably, the conversion rate of ethylbenzene is higher than 70%, and the selectivity of acetophenone is higher than 70%; Preferably, during the catalytic oxidation of ethylbenzene, under the conditions of an oxygen pressure of 1 MPa and a reaction temperature of 80° C. for more than 9 hours, the conversion rate of ethylbenzene is higher than 80%, and the selectivity of acetophenone is higher than 80%.
10. The method for selective catalytic oxidation of aromatics according to claim 1, characterized in that: When toluene is catalytically oxidized, under the conditions of oxygen pressure of 1 MPa, reaction temperature of 80°C and reaction time of more than 5 hours: the conversion rate of toluene is higher than 40%, and the selectivity of benzoic acid is higher than 70%; Preferably, during the catalytic oxidation of toluene, under the conditions of an oxygen pressure of 1 MPa and a reaction temperature of 80°C for more than 9 hours: the conversion rate of toluene is higher than 50%, and the selectivity of benzoic acid is higher than 80%; further preferably, the conversion rate of toluene is higher than 70%, and the selectivity of benzoic acid is higher than 80%.
11. The method for selective catalytic oxidation of aromatic hydrocarbons according to claim 1, characterized in that: When fluorene is catalytically oxidized, under the conditions of oxygen pressure of 1MPa, reaction temperature of 80℃ and reaction time of more than 9h: the conversion rate of fluorene is higher than 90%, and the selectivity of fluorenone is higher than 90%; Preferably, when indene is catalytically oxidized, under the conditions of an oxygen pressure of 1 MPa and a reaction temperature of 80° C. for 9 h, the conversion rate of fluorene is higher than 90%, and the selectivity of indanone is higher than 90%.