Catalyst system and application thereof in alkyl benzene peroxidation reaction

Abstract

The invention discloses a catalyst system and application thereof in an alkylbenzene peroxidation reaction. The catalyst system comprises a main catalyst; the catalyst system is used in a reaction for preparing alkylbenzene peroxide through an alkylbenzene peroxidation reaction, the initiation efficiency and the reaction efficiency of the peroxidation reaction can be greatly improved, and the conversion rate of the peroxidation reaction and the selectivity of the alkylbenzene peroxide are improved.

Description

Technical Field

[0001] This invention belongs to the field of catalysis technology, and particularly relates to a catalyst system and its application in the peroxidation reaction of alkylbenzene. Background Technology

[0002] In peroxidation reactions, the initial initiation process is extremely slow, usually requiring the addition of a certain amount of initiator or catalyst, or an increase in reaction temperature to achieve the initial free radical initiation process. For reactions that are difficult to initiate, multi-stage oxidation towers are often needed to achieve the target requirements for reaction selectivity and conversion rate. How to accelerate the initiation efficiency and increase the rate of peroxidation reactions is a key focus of peroxidation reaction research.

[0003] CN101541745A proposes using NHPI catalysts to improve the conversion and selectivity of cumene peroxidation. However, to increase the reaction rate during the initiation phase, additional peroxyacid compounds are required. The organic acids formed after the reaction of these peroxyacid compounds can decompose the peroxide, leading to lower reaction selectivity. CN109574898A reports a method for preparing aromatic isopropyl hydrogen peroxide using microchannel oxidation, but this still requires the addition of azobisisobutyronitrile (AIBN) as an initiator. Furthermore, microchannel technology has high equipment requirements, limiting its industrial application. Improving the initiation efficiency and reducing the difficulty of initiation could reduce the number of oxidation towers, thereby lowering the reaction process cost and improving economic efficiency. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a catalyst system and its application in the alkylbenzene peroxidation reaction. The catalyst system of this invention, used in the alkylbenzene peroxidation reaction to prepare alkylbenzene peroxides, can significantly improve the initiation efficiency and reaction efficiency of the peroxidation reaction, as well as the conversion rate and selectivity of the alkylbenzene peroxide.

[0005] This invention provides a catalyst system, including a main catalyst; the structural formula of the main catalyst is as follows:

[0006]

[0007] Furthermore, the catalyst system also includes a co-catalyst I, which is a benzyl alcohol compound with the following structural formula:

[0008]

[0009] R1 and R2 are each independently selected from hydrogen, alkyl or cycloalkyl, wherein the alkyl is preferably a C1-C4 straight-chain alkyl, and further R1 and R2 are each independently selected from methyl or ethyl; R3 is selected from hydrogen, alkyl, alkoxy, halogen, nitro, carbonyl or ester, preferably methyl, ethyl, propyl or isopropyl.

[0010] Further, the co-catalyst I is preferably at least one of 2-phenyl-2-propanol, 2-(4-methylphenyl)-2-propanol, phenylcyclohexanol, 4-tolylcyclohexanol, and benzyl alcohol, preferably 2-phenyl-2-propanol.

[0011] Furthermore, the catalyst system also includes a co-catalyst II, which comprises at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, and potassium dihydrogen phosphate, preferably sodium carbonate. The co-catalyst II can be added in solid form or in aqueous solution form. When an aqueous solution is used, the concentration of the co-catalyst II aqueous solution is 1 wt%-15 wt%.

[0012] Furthermore, the main catalyst is preferably prepared using the following route:

[0013]

[0014] Further, the preparation method of the main catalyst includes: dissolving isopropyl-substituted N-hydroxyphthalimide (isopropyl-substituted NHPI) in acetonitrile solution, wherein the concentration of isopropyl-substituted NHPI is 5-15 wt%, preferably 9-11 wt%; subsequently adding azobisisobutyronitrile (AIBN) as an initiator, wherein the amount of AIBN is 2-8% of the mass of isopropyl-substituted NHPI, preferably 4-6%; continuously introducing oxygen-containing gas (e.g., air), wherein the flow rate of the oxygen-containing gas is 0.2-2.0 mL / min, preferably 1.0-1.2 mL / min, relative to 1 mL of isopropyl-substituted NHPI acetonitrile solution; heating under reflux at a reaction temperature of 80-85°C for a reaction time of 18-32 hours, preferably 23-25 ​​hours; and then drying the solvent by rotary evaporation to obtain the main catalyst.

[0015] Furthermore, in the catalyst system, the mass ratio of the main catalyst to the co-catalyst I is 1:0.01-10, preferably 1:0.05-0.5. The mass ratio of the main catalyst to the co-catalyst I can be, for example, 1:0.01, 1:0.02, 1:0.04, 1:0.05, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.8, 1:1, 1:3, 1:5, 1:8, 1:10, etc., and any value within any range formed by any two of these values.

[0016] Furthermore, in the catalyst system, the mass ratio of the main catalyst to the co-catalyst II is 1:0.1-100, preferably 1:2.5-50. The mass ratio of the main catalyst to the co-catalyst II can be, for example, 1:0.1, 1:1.0, 1:2.5, 1:5, 1:7, 1:8, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, etc., and any value within any range formed by any two of these values.

[0017] Furthermore, the catalyst system is a catalyst system used for the preparation of alkylbenzene peroxides by the alkylbenzene peroxidation reaction.

[0018] A second aspect of the present invention provides the application of the above-described catalyst system in the preparation of alkylbenzene peroxides by the alkylbenzene peroxidation reaction.

[0019] Furthermore, the application includes: reacting alkylbenzene with the above catalyst system in the presence of oxygen-containing gas to obtain alkylbenzene peroxide.

[0020] Furthermore, there are no particular restrictions on how the catalyst system is added to the reaction system. The main catalyst, co-catalyst I, and co-catalyst II can be added to the reaction system separately, or the main catalyst, co-catalyst I, and co-catalyst II can be mixed and then added to the reaction system.

[0021] Furthermore, a solvent may or may not be used in the reaction system. Acetonitrile is generally used as the solvent, but no solvent is usually added for the production of liquid alkylbenzenes.

[0022] Furthermore, in the reaction system, the amount of the main catalyst is 0.01wt%-0.30wt%, preferably 0.1wt%-0.20wt%.

[0023] Furthermore, in the reaction system, the amount of co-catalyst I is 0.001wt%-1.0wt%, preferably 0.01wt%-0.05wt%.

[0024] Furthermore, in the reaction system, the amount of co-catalyst II is 0.001% wt-10.0 wt%, preferably 0.5 wt%-5.0 wt%.

[0025] Further, the alkylbenzene is at least one selected from cumene, cyclohexylbenzene, diisopropylbenzene, or methylisopropylbenzene. Correspondingly, the peroxides corresponding to cumene, cyclohexylbenzene, diisopropylbenzene, or methylisopropylbenzene are, in order, cumene peroxide, cyclohexylbenzene peroxide, diisopropylbenzene bisperoxide, and methylisopropylbenzene tertiary peroxide, respectively, as shown in the table below.

[0026]

[0027] Furthermore, the oxygen-containing gas has an oxygen volume content of 10%-100%. The oxygen-containing gas can be air.

[0028] Furthermore, the reaction conditions are as follows: reaction temperature 70-110℃; and / or, reaction pressure atmospheric pressure to 0.5MPa; and / or, reaction time 4-24 hours; and / or, the flow rate of oxygen-containing gas relative to 500g of raw material is 100-1200mL / min.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The catalyst system of this invention is used in the preparation of alkylbenzene peroxides by alkylbenzene peroxidation reaction. By combining the initiator with the peroxidation catalyst, a self-initiating peroxidation catalyst is formed, which changes the intermolecular chain transfer reaction during the initiation process into an intramolecular chain transfer reaction. This can greatly improve the initiation efficiency and reaction efficiency of the peroxidation reaction, and improve the conversion rate and selectivity of the alkylbenzene peroxide. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the embodiments.

[0032] The main catalyst used in the examples was a self-made catalyst, and the isopropyl-substituted N-hydroxyphthalimide and co-catalysts I and II were commercially available products.

[0033] The preparation method of the main catalyst used in this embodiment of the invention is as follows: Isopropyl-substituted NHPI is dissolved in acetonitrile solution at a concentration of 10 wt%. AIBN is then added as an initiator at a concentration of 5% of the mass of the isopropyl-substituted NHPI. Oxygen is continuously introduced at a flow rate of 1.1 mL / min relative to 1 mL of isopropyl-substituted NHPI acetonitrile solution. The mixture is heated to reflux at a temperature of 85 °C for 24 hours. The solvent is then evaporated under low temperature and low vacuum to obtain the main catalyst.

[0034] In this invention, both conversion rate and selectivity are expressed as mass fractions.

[0035] Example 1

[0036] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst, 2.5g (0.5wt%) of sodium carbonate, and 0.05g (0.01wt%) of 2-phenyl-2-propanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 6 hours to finally obtain cumene peroxide. The conversion rate of cumene was 26.5%, and the selectivity of cumene peroxide reached 98.8%.

[0037] Example 2

[0038] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst, 2.5g (0.5wt%) of sodium carbonate, and 0.25g (0.05wt%) of 2-phenyl-2-propanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 6 hours to finally obtain cumene peroxide. The conversion rate of cumene was 26.3%, and the selectivity of cumene peroxide reached 99.0%.

[0039] Example 3

[0040] 500g of cumene was added to a three-necked flask, along with 1g (0.2wt%) of the main catalyst, 2.5g (0.5wt%) of sodium carbonate, and 0.05g (0.01wt%) of 2-phenyl-2-propanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 4 hours to finally obtain cumene peroxide. The conversion rate of cumene was 26.0%, and the selectivity of cumene peroxide reached 98.6%.

[0041] Example 4

[0042] 500g of cumene was added to a three-necked flask, along with 0.05g (0.1wt%) of the main catalyst, 2.5g (0.5wt%) of sodium carbonate, and 0.05g (0.01wt%) of benzyl alcohol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cumene peroxide. The conversion rate of cumene was 26.5%, and the selectivity of cumene peroxide reached 97.8%.

[0043] Example 5

[0044] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst, 50g (10wt%) of sodium carbonate, and 0.05g (0.01wt%) of 2-phenyl-2-propanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cumene peroxide. The conversion rate of cumene was 26.4%, and the selectivity of cumene peroxide reached 92.0%.

[0045] Example 6

[0046] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst, 25g (5wt%) of disodium hydrogen phosphate, and 0.05g (0.01wt%) of 2-phenyl-2-propanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cumene peroxide. The conversion rate of cumene was 26.3%, and the selectivity of cumene peroxide reached 95.8%.

[0047] Example 7

[0048] 500g of cyclohexylbenzene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst, 10g (2wt%) of sodium carbonate, and 0.1g (0.02wt%) of phenylcyclohexanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cyclohexylbenzene peroxide. The conversion rate of cyclohexylbenzene was 20.3%, and the selectivity of cyclohexylbenzene peroxide reached 94.2%.

[0049] Example 8

[0050] 500g of methyl cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst, 25g (5wt%) of sodium carbonate, and 0.1g (0.02wt%) of 2-(4-methylphenyl)-2-propanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 105℃ for 10 hours to finally obtain methyl cumene tertiary peroxide. The conversion rate of methyl cumene was 18.7%, and the selectivity of methyl cumene tertiary peroxide reached 86.6%.

[0051] Example 9

[0052] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst, 25g (1wt%) of sodium carbonate, and 0.05g (0.01wt%) of phenylcyclohexanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cumene peroxide. The conversion rate of cumene was 23.7%, and the selectivity of cumene peroxide reached 96.2%.

[0053] Example 10

[0054] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst, 12.5g (0.5wt%) of sodium carbonate, and 0.05g (0.01wt%) of 2-phenyl-2-propanol. Oxygen was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 4 hours to finally obtain cumene peroxide. The conversion rate of cumene was 27.0%, and the selectivity of cumene peroxide reached 99.0%.

[0055] Example 11

[0056] 500g of p-diisopropylbenzene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst, 25g (1wt%) of sodium carbonate, and 0.05g (0.01wt%) of 2-phenyl-2-propanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain diisopropylbenzene bisperoxide. The conversion rate of p-diisopropylbenzene was 35.0%, and the selectivity of diisopropylbenzene bisperoxide reached 78.0%.

[0057] Example 12

[0058] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst and 25g (5wt%) of disodium hydrogen phosphate. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cumene peroxide. The conversion rate of cumene was 24.4%, and the selectivity of cumene peroxide reached 89.0%.

[0059] Example 13

[0060] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of the main catalyst and 0.05g (0.01wt%) of 2-phenyl-2-propanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cumene peroxide. The conversion rate of cumene was 14.6%, and the selectivity of cumene peroxide reached 94.0%.

[0061] Comparative Example 1

[0062] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of isopropyl-substituted NHPI, 25g (5wt%) of disodium hydrogen phosphate, and 0.05g (0.01wt%) of 2-phenyl-2-propanol. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cumene peroxide. The conversion rate of cumene was 7.2%, and the selectivity of cumene peroxide reached 91.3%.

[0063] Comparative Example 2

[0064] 500g of cyclohexylbenzene was added to a three-necked flask, along with 0.5g of NHP (0.1wt%), 25g of sodium carbonate (5wt%), and 0.1g of phenylcyclohexanol (0.02wt%). Air was bubbled through the flask (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cyclohexylbenzene peroxide. The conversion rate of cyclohexylbenzene was 6.5%, and the selectivity of cyclohexylbenzene peroxide reached 91.0%.

[0065] Comparative Example 3

[0066] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of isopropyl-substituted NHPI and 25g (5wt%) of disodium hydrogen phosphate. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cumene peroxide. The conversion rate of cumene was 8.0%, and the selectivity of cumene peroxide reached 86.4%.

[0067] Comparative Example 4

[0068] 500g of cumene was added to a three-necked flask, along with 0.5g of NHPI (0.1wt%) and 25g of disodium hydrogen phosphate (5wt%). Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cumene peroxide. The conversion rate of cumene was 7.8%, and the selectivity of cumene peroxide reached 85.7%.

[0069] Comparative Example 5

[0070] 500g of cumene was added to a three-necked flask, along with 0.5g (0.1wt%) of NHPI. Air was introduced (flow rate 1000ml / min), and the reaction was carried out at 80℃ for 10 hours to finally obtain cumene peroxide. The conversion rate of cumene was 4.9%, and the selectivity of cumene peroxide reached 80.6%.

Claims

1. A catalyst system comprising a main catalyst; the structural formula of the main catalyst is as follows:

2. The catalyst system according to claim 1, characterized in that, The catalyst system also includes a co-catalyst I, which is a benzyl alcohol compound with the following structural formula: R1 and R2 are each independently selected from hydrogen, alkyl or cycloalkyl, wherein the alkyl is preferably a C1-C4 straight-chain alkyl, and further R1 and R2 are each independently selected from methyl or ethyl; R3 is selected from hydrogen, alkyl, alkoxy, halogen, nitro, carbonyl or ester, preferably methyl, ethyl, propyl or isopropyl. Preferably, the co-catalyst I is at least one of 2-phenyl-2-propanol, 2-(4-methylphenyl)-2-propanol, phenylcyclohexanol, 4-tolylcyclohexanol, and benzyl alcohol, and more preferably 2-phenyl-2-propanol.

3. The catalyst system according to claim 2, characterized in that, In the catalyst system, the mass ratio of the main catalyst to the co-catalyst I is 1:0.01-10, preferably 1:0.05-0.

5.

4. The catalyst system according to any one of claims 1-3, characterized in that, The catalyst system further includes a co-catalyst II, which includes at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, and potassium dihydrogen phosphate, preferably sodium carbonate.

5. The catalyst system according to claim 4, characterized in that, In the catalyst system, the mass ratio of the main catalyst to the co-catalyst II is 1:0.1-100, preferably 1:2.5-50.

6. The catalyst system according to claim 1, characterized in that, The main catalyst was prepared using the following route:

7. The catalyst system according to claim 6, characterized in that, The preparation method of the main catalyst includes: dissolving isopropyl-substituted N-hydroxyphthalimide (isopropyl-substituted NHPI) in acetonitrile solution, wherein the concentration of isopropyl-substituted NHPI is 5-15 wt%, preferably 9-11 wt%; subsequently adding azobisisobutyronitrile (AIBN) as an initiator, wherein the amount of AIBN is 2-8% of the mass of isopropyl-substituted NHPI, preferably 4-6%; continuously introducing oxygen-containing gas (e.g., air), wherein the flow rate of the oxygen-containing gas is 0.2-2.0 mL / min, preferably 1.0-1.2 mL / min, relative to 1 mL of isopropyl-substituted NHPI acetonitrile solution; heating under reflux at a reaction temperature of 80-85 °C for a reaction time of 18-32 hours, preferably 23-25 ​​hours; and then drying the solvent by rotary evaporation to obtain the main catalyst.

8. The catalyst system according to claim 1, characterized in that, The catalyst system is a catalyst system used for the preparation of alkylbenzene peroxides by the alkylbenzene peroxidation reaction.

9. The use of the catalyst system according to any one of claims 1-8 in the preparation of alkylbenzene peroxides by alkylbenzene peroxidation reaction.

10. The application according to claim 9, characterized in that, The application includes: reacting alkylbenzene with the catalyst system in the presence of oxygen-containing gas to obtain alkylbenzene peroxide; Preferably, the amount of the main catalyst in the reaction system is 0.01wt%-0.30wt%, and more preferably 0.1wt%-0.20wt%. Preferably, the amount of co-catalyst I in the reaction system is 0.001 wt%-1.0 wt%, more preferably 0.01 wt%-0.05 wt%. Preferably, the amount of co-catalyst II in the reaction system is 0.001% wt-10.0 wt%, more preferably 0.5 wt%-5 wt%; Preferably, the alkylbenzene is at least one of cumene, cyclohexylbenzene, diisopropylbenzene or methylisopropylbenzene, and is preferably cumene; Preferably, the oxygen volume content of the oxygen-containing gas is 10%-100%; Preferably, the reaction conditions are as follows: reaction temperature 70-110℃; and / or, reaction pressure atmospheric pressure to 0.5MPa; and / or, reaction time 4-24 hours; and / or, the flow rate of oxygen-containing gas relative to 500g of raw material is 100-1200mL / min.

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