Composite catalyst and its use in the synthesis of alkyl peroxides

Abstract

The application discloses a composite catalyst and application thereof in synthesis of alkyl peroxide. The composite catalyst comprises a molecular sieve main catalyst with medium Brnsted acidity and a Lewis acid cocatalyst supported by a non-acid carrier. The composite catalyst provided by the application has the advantages of high activity, high reaction selectivity and long-term stability in the reaction for synthesizing alkyl peroxide.

Description

Technical Field

[0001] This invention relates to a reaction catalyst and its application, and more particularly to a composite catalyst and its application in the synthesis of alkyl peroxides. Background Technology

[0002] Dicumyl peroxide (DCP) is mainly used as a crosslinking agent for various olefin polymers and copolymers, including polyethylene, chlorinated polyethylene, and silicone rubber, as well as a polymerization initiator for polystyrene. It is also a curing agent for unsaturated polyester resins, thus finding wide application in industries such as wire and cable, shoemaking, and building materials. In recent years, with the continuous expansion of the polymer materials market, the demand for DCP has been increasing year by year, indicating huge market potential.

[0003] Currently, the industrial production of dicumyl peroxide mainly adopts a condensation process, which involves the condensation reaction of cumyl peroxide (CHP) and dimethyl benzyl alcohol (DMCA) under the action of an acidic catalyst.

[0004] Patent US4266081A discloses a method for preparing dicumyl peroxide using a strong acid-weak base salt (such as zinc chloride) as a catalyst. The disadvantage of this patent is that the amount of catalyst used is large and the catalyst cannot be recovered or reused.

[0005] Patents CN103145597B, CN104860861A, and CN107382806A disclose a method for preparing dicumyl peroxide using strong protic acids (such as sulfuric acid and perchloric acid) as catalysts. The disadvantages of this patent are: firstly, the protic acid catalyst requires high concentrations and large quantities in the condensation reaction, necessitating neutralization with a strong alkali solution during product purification. This neutralization process generates large amounts of saline wastewater that is difficult to treat and discharge, causing severe environmental pollution. Secondly, water is generated during the condensation process, and the increased water volume reduces the acid concentration, thereby decreasing the condensation reaction rate, prolonging the reaction time, and affecting production efficiency. Furthermore, the protic acid catalyst cannot be regenerated or recycled.

[0006] Patent CN113845457A discloses a method for SO4 2- A method for preparing dicumyl peroxide from dimethylbenzyl alcohol and cumene peroxide by dehydration condensation in the presence of a ZnCl2-HY solid acid catalyst. The main drawbacks of this patent are: poor activity of the solid acid catalyst, the need for high reaction temperatures, severe decomposition of both the raw material cumene peroxide and the product dicumyl peroxide, resulting in low utilization of the raw material and low product yield; furthermore, with increasing usage, the loss of active components in the catalyst leads to a reduction in acidic sites, decreased catalytic performance, and a significantly shortened catalyst lifetime.

[0007] In summary, the current condensation process for the industrial production of dicumyl peroxide still faces challenges such as high catalyst usage, low activity, low raw material utilization, and poor product selectivity, which still need to be addressed. Summary of the Invention

[0008] To address the above technical problems, this invention proposes a composite catalyst and its application in the synthesis of alkyl peroxides. The composite catalyst provided by this invention, when used in the synthesis of alkyl peroxides, exhibits advantages such as high activity, high reaction selectivity, and long-term stability.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A composite catalyst comprising a molecular sieve master catalyst of moderate Brønsted acidity and a Lewis acid co-catalyst supported on a non-acidic support.

[0011] In the composite catalyst, the content of the main catalyst is 50-90 wt%, preferably 60-80 wt%, more preferably 65-75 wt%, and the content of the co-catalyst is 10-50 wt%, preferably 20-40 wt%, more preferably 25-35 wt%. The content of Lewis acid in the co-catalyst is 1-10 wt%, preferably 3-7 wt%, more preferably 4-6 wt%, based on the weight of the non-acidic support as 100 wt%.

[0012] This invention enables the composite catalyst to possess high activity, selectivity, and good stability through the synergistic effect of the main catalyst and the co-catalyst.

[0013] In a preferred embodiment of the present invention, the main catalyst is a molecular sieve with a Brønsted acidity of 100-300 μmol / g, preferably 140-260 μmol / g, and more preferably 180-220 μmol / g.

[0014] In a preferred embodiment of the present invention, the main catalyst has a specific surface area of ​​100-900 m². 2 / g, preferably 300-800m 2 / g, more preferably 500-700m 2 / g, total pore volume 0.1-1.0ml / g, preferably 0.2-0.8ml / g, more preferably 0.4-0.6ml / g, Na2O content 0.01-0.1%, preferably 0.02-0.08%, more preferably 0.03-0.06%, Si / Al molar ratio 20-70, preferably 30-60, more preferably 40-50 molecular sieve.

[0015] As a preferred embodiment of the present invention, the molecular sieve is selected from one or more of ZSM-5, ZSM-22, high-silica Y-type molecular sieve, β-type zeolite, MCM-22, MCM-41, and mordenite, preferably one or more of ZSM-5, ZSM-22, high-silica Y-type molecular sieve, and MCM-22, and more preferably ZSM-5 and / or high-silica Y-type molecular sieve.

[0016] As a preferred embodiment of the present invention, the non-acidic carrier is one or more of zinc oxide, magnesium oxide, silicon oxide, aluminum oxide, titanium oxide, silicon carbide, calcium oxide and zirconium oxide, preferably one or more of zinc oxide, aluminum oxide, silicon oxide and zirconium oxide, and more preferably zinc oxide or zirconium oxide.

[0017] In a preferred embodiment of the present invention, the Lewis acid is one or more of copper chloride, zinc chloride, zinc sulfate, ammonium bisulfate and cerium ammonium nitrate, preferably one or more of copper chloride and cerium ammonium nitrate, and more preferably cerium ammonium nitrate.

[0018] The present invention does not impose any restrictions on the preparation method of the cocatalyst, which can be prepared by at least one of the following methods: impregnation, deposition precipitation, sol-gel method, and ion exchange method, with impregnation being preferred.

[0019] Examples of feasible preparation methods, such as those for the general method of preparing supported catalysts by impregnation, include:

[0020] A non-acidic support is impregnated in an aqueous solution containing Lewis acid, and after adsorption equilibrium is reached, it is dried and calcined to obtain a co-catalyst.

[0021] The relative amounts of the non-acidic support and Lewis acid are determined based on the desired theoretical composition of the cocatalyst. Optional calcination conditions include, for example: calcination temperature of 200-700℃, preferably 300-600℃, more preferably 400-500℃, under an inert gas atmosphere; and calcination time of 2-10h, preferably 3-8h, more preferably 4-6h.

[0022] As a preferred embodiment of the present invention, the composite catalyst is prepared by mixing a main catalyst and a co-catalyst, followed by drying and calcination; preferably, the powder is ground and sieved before drying so that it passes through a 100-200 mesh sieve.

[0023] Preferably, the calcination conditions are: under an inert gas atmosphere, a calcination temperature of 500-1000℃, more preferably 600-900℃, and more preferably 700-800℃; and a calcination time of 2-8h, more preferably 4-7h, and more preferably 5-6h.

[0024] Application of a composite catalyst as described above in the synthesis of alkyl peroxides.

[0025] A method for preparing dicumyl peroxide includes a condensation reaction in a fixed-bed reactor using dicumyl peroxide and dimethylbenzyl alcohol as raw materials, under the action of the composite catalyst described above, to obtain dicumyl peroxide.

[0026] As a preferred embodiment of the present invention, the cumene peroxide, dimethylbenzyl alcohol and solvent are fed into the feed after forming a mixed solution, and the total feed space velocity is 1-10 L / h / L·cat, preferably 3-7 L / h / L·cat, more preferably 4-6 L / h / L·cat.

[0027] Preferably, the molar ratio of cumene peroxide and dimethyl benzyl alcohol is (0.8-1.2):1, more preferably (0.9-1.1):1, and even more preferably (1.0-1.05):1;

[0028] Preferably, the mass concentration of cumene peroxide is 40-80 wt%, more preferably 50-70 wt%, and even more preferably 55-65 wt%, based on a total mass of cumene peroxide and solvent of 100 wt%.

[0029] Preferably, the reaction temperature of the condensation reaction is 30-60℃, more preferably 40-50℃, and even more preferably 43-47℃.

[0030] Preferably, the solvent is one or more selected from cumene, diisopropylbenzene, toluene, xylene, n-hexane, and cyclohexane.

[0031] As is known in the art, in addition to the main reaction, the above-mentioned condensation reaction may also involve side reactions such as the decomposition of cumene peroxide and the dehydration of dimethyl benzyl alcohol. The impurities may include phenol, α-methylstyrene, acetone, etc., which can lead to a decrease in the effective utilization rate of raw materials and a decrease in product selectivity.

[0032] The composite catalyst of this invention is used to synthesize dicumyl peroxide via a condensation reaction. It has a high feed conversion rate, high product selectivity, and the catalyst can operate continuously and stably for more than 1000 hours, making it particularly suitable for the continuous production of dicumyl peroxide. Detailed Implementation

[0033] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0034] The reaction conversion rate and selectivity were determined using the external standard curve method of liquid chromatography.

[0035] The chromatographic analysis conditions were as follows: Shimadzu SPD-20A liquid chromatograph; column oven: CT0-10ASvp; column temperature: 35℃; column: T3 column; mobile phase: water and acetonitrile, water / acetonitrile = 25:75 (vol / vol); total flow rate: 1 ml / min; residence time: 40 min; detector wavelength: 254 nm.

[0036] The reactor in this example is a fixed-bed reactor.

[0037] The main information about the molecular sieves in the following examples is as follows:

[0038] ZSM-5 (Si / Al = 85): Specific surface area 350 m² 2 / g, total pore volume 0.6ml / g, Na2O content 0.04%, Tianjin Nanhua Catalyst Co., Ltd.

[0039] ZSM-5 (Si / Al = 70): Specific surface area 350 m² 2 / g, total pore volume 0.6ml / g, Na2O content 0.04%, Tianjin Nanhua Catalyst Co., Ltd.

[0040] ZSM-5 (Si / Al = 21): Specific surface area 352 m² 2 / g, total pore volume 0.4ml / g, Na2O content 0.03%, Tianjin Nanhua Catalyst Co., Ltd.

[0041] ZSM-5 (Si / Al = 18.4): Specific surface area 350 m² 2 / g, total pore volume 0.6ml / g, Na2O content 0.04%, Tianjin Nanhua Catalyst Co., Ltd.

[0042] ZSM-22 (Si / Al = 42): Specific surface area 180 m² 2 / g, total pore volume 0.8ml / g, Na2O content 0.04%, Tianjin Nanhua Catalyst Co., Ltd.

[0043] High-silica Y-type molecular sieve (Si / Al = 43): specific surface area 670 m² 2 / g, total pore volume 0.5ml / g, Na2O content 0.02%, Tianjin Nanhua Catalyst Co., Ltd.

[0044] MCM-22 (Si / Al = 28): Specific surface area 440 m² 2 / g, total pore volume 0.2ml / g, Na2O content 0.04%, Tianjin Nanhua Catalyst Co., Ltd.

[0045] The following Examples 1-6 and Comparative Examples 1-4 are used to provide composite catalysts with different compositions.

[0046]

Example 1

[0047] Weigh 100g of zinc oxide support and add it to 100ml of aqueous solution containing 4.0g of copper chloride using the equal volume impregnation method. After adsorption equilibrium is reached, dry at 130℃ for 6h and calcine at 400℃ for 4h under nitrogen atmosphere to obtain the co-catalyst.

[0048] 50g of ZSM-5 (Si / Al=70) and 50g of the above-mentioned co-catalyst were added to a mortar and mixed evenly. After grinding and sieving, a mixture was obtained. Then, the mixture was transferred to a crucible and dried at 130℃ for 6h. After calcination at 500℃ for 8h under a nitrogen atmosphere, a 3*3mm composite catalyst A was obtained by pressing into tablets.

[0049]

Example 2

[0050] Weigh 100g of alumina support and add it to 100ml of aqueous solution containing 6.0g of zinc chloride using the equal volume impregnation method. After adsorption equilibrium is reached, dry at 120℃ for 4h and calcine at 500℃ for 6h under nitrogen atmosphere to obtain the co-catalyst.

[0051] 60g of ZSM-5 (Si / Al=21) and 40g of the above-mentioned co-catalyst were added to a mortar and mixed evenly. After grinding and sieving, a mixture was obtained. Then, the mixture was transferred to a crucible and dried at 120℃ for 4h. After calcination at 600℃ for 7h under a nitrogen atmosphere, a 3*3mm composite catalyst B was obtained by extrusion molding.

[0052]

Example 3

[0053] Weigh 100g of silica support and add it to 100ml of aqueous solution containing 3.0g of cerium ammonium nitrate using the equal volume impregnation method. After adsorption equilibrium is reached, dry it at 140℃ for 8h and calcine it at 300℃ for 8h under nitrogen atmosphere to obtain the co-catalyst.

[0054] 65g of ZSM-22 (Si / Al=42) and 35g of the above-mentioned co-catalyst were added to a mortar and mixed evenly. After grinding and sieving, a mixture was obtained. Then, the mixture was transferred to a crucible and dried at 140℃ for 8h. After calcination at 700℃ for 6h under a nitrogen atmosphere, a 3*3mm composite catalyst C was obtained by extrusion molding.

[0055]

Example 4

[0056] Weigh 100g of zirconium oxide support and add it to 100ml of aqueous solution containing 7.0g of cerium ammonium nitrate using the equal volume impregnation method. After adsorption equilibrium is reached, dry it at 150℃ for 2h and calcine it at 600℃ for 3h under nitrogen atmosphere to obtain the co-catalyst.

[0057] 75g of high-silicon Y-type catalyst (Si / Al = 43) and 25g of the above-mentioned co-catalyst were added to a mortar and mixed evenly. After grinding and sieving, a mixture was obtained. Then, the mixture was transferred to a crucible and dried at 150°C for 2 hours. After calcination at 800°C for 5 hours under a nitrogen atmosphere, a 3*3mm composite catalyst D was obtained by pressing into tablets.

[0058]

Example 5

[0059] Weigh 100g of zinc oxide support and add it to 100ml of aqueous solution containing 1.0g of cerium ammonium nitrate using the equal volume impregnation method. After adsorption equilibrium is reached, dry at 100℃ for 10h and calcine at 200℃ for 10h under nitrogen atmosphere to obtain the co-catalyst.

[0060] 80g of high-silicon Y-type catalyst (Si / Al = 43) and 20g of the above-mentioned co-catalyst were added to a mortar and mixed evenly. After grinding and sieving, a mixture was obtained. Then, the mixture was transferred to a crucible and dried at 100°C for 10h. After calcination at 900°C for 4h under a nitrogen atmosphere, a 3*3mm composite catalyst E was obtained by pressing into tablets.

[0061]

Example 6

[0062] Weigh 100g of zinc oxide support and add it to 100ml of aqueous solution containing 10.0g of zinc sulfate using the equal volume impregnation method. After adsorption equilibrium is reached, dry at 110℃ for 9h and calcine at 700℃ for 2h under nitrogen atmosphere to obtain the co-catalyst.

[0063] 90g of MCM-22 (Si / Al=28) and 10g of the above-mentioned co-catalyst were added to a mortar and mixed evenly. After grinding and sieving, a mixture was obtained. Then, the mixture was transferred to a crucible and dried at 110℃ for 9h. After calcination at 1000℃ for 2h under a nitrogen atmosphere, a 3*3mm composite catalyst F was obtained by pressing into tablets.

[0064] Comparative Example 1

[0065] The composite catalyst was prepared using a method essentially the same as that in Example 1, except that copper chloride was not added during the preparation of the co-catalyst, and the final composite catalyst A-1 was obtained.

[0066] Comparative Example 2

[0067] The composite catalyst was prepared using a method essentially the same as in Example 1, except that copper chloride was replaced with aluminum trichloride when preparing the co-catalyst, and the composite catalyst A-2 was finally obtained.

[0068] Comparative Example 3

[0069] The composite catalyst was prepared using a method essentially the same as in Example 1, except that ZSM-5 (Si / Al = 70) was replaced with ZSM-5 (Si / Al = 18.4), and the composite catalyst A-3 was finally obtained.

[0070] Comparative Example 4

[0071] The composite catalyst was prepared using a method essentially the same as in Example 1, except that ZSM-5 (Si / Al = 70) was replaced with ZSM-5 (Si / Al = 85), and the composite catalyst A-4 was finally obtained.

[0072] The following Application Examples 1-6 and Comparative Examples 1-4 were used to synthesize dicumyl peroxide to evaluate the catalyst performance.

[0073]

Application Example 1

[0074] 50 ml of catalyst A was added to the reactor, and the temperature was raised to 43 °C. After the system stabilized, a cumene solution with a CHP / DMCA molar ratio of 1:1 (wherein the CHP mass concentration was 55%, relative to the total weight of CHP and cumene solvent being 100%) was pumped into the reactor at a space velocity of 4 L / h / L·cat. After reacting for 10 h, liquid chromatography analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 99.64%, the selectivity for phenol was 0.06%, the selectivity for α-methylstyrene was 0.25%, and the selectivity for acetone was 0.05% (based on CHP). After continuous operation for 1100 h, a second sample was taken for analysis, and the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 99.09%, the selectivity for phenol was 0.40%, the selectivity for α-methylstyrene was 0.35%, and the selectivity for acetone was 0.16% (based on CHP).

[0075]

Application Example 2

[0076] 50 ml of catalyst B was added to the reactor, and the temperature was raised to 40 °C. After the system stabilized, a cumene solution with a CHP / DMCA molar ratio of 0.9:1 (wherein the CHP mass concentration was 50%, relative to the total weight of CHP and cumene solvent being 100%) was pumped into the reactor at a space velocity of 3 L / h / L·cat. After 20 h of reaction, liquid chromatography analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 99.62%, the selectivity for phenol was 0.10%, the selectivity for α-methylstyrene was 0.17%, and the selectivity for acetone was 0.11% (based on CHP). After continuous operation for 1200 h, further sampling and analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 98.36%, the selectivity for phenol was 0.18%, the selectivity for α-methylstyrene was 0.25%, and the selectivity for acetone was 3.55% (based on CHP).

[0077]

Application Example 3

[0078] 50 ml of catalyst C was added to the reactor, and the temperature was raised to 30 °C. After the system stabilized, a cumene solution with a CHP / DMCA molar ratio of 1.05:1 (wherein the CHP mass concentration was 40%, relative to the total weight of CHP and cumene solvent being 100%) was pumped into the reactor at a space velocity of 1 L / h / L·cat. After reacting for 10 h, liquid chromatography analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 99.44%, the selectivity for phenol was 0.16%, the selectivity for α-methylstyrene was 0.20%, and the selectivity for acetone was 0.2%, based on CHP. After continuous operation for 1150 h, further sampling and analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 99.13%, the selectivity for phenol was 0.32%, the selectivity for α-methylstyrene was 0.29%, and the selectivity for acetone was 0.26%, based on CHP.

[0079]

Application Example 4

[0080] 50 ml of catalyst D was added to the reactor, and the temperature was raised to 47 °C. After the system stabilized, a cumene solution with a CHP / DMCA molar ratio of 1.1:1 (wherein the CHP mass concentration was 65%, relative to the total weight of CHP and cumene solvent being 100%) was pumped into the reactor at a space velocity of 6 L / h / L·cat. After reacting for 15 h, liquid chromatography analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 99.7%, the selectivity for phenol was 0.08%, the selectivity for α-methylstyrene was 0.18%, and the selectivity for acetone was 0.04% (based on CHP). After continuous operation for 1300 h, further sampling and analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 99.05%, the selectivity for phenol was 0.42%, the selectivity for α-methylstyrene was 0.38%, and the selectivity for acetone was 0.15% (based on CHP).

[0081]

Application Example 5

[0082] 50 ml of catalyst E was added to the reactor, and the temperature was raised to 50 °C. After the system stabilized, a cumene solution with a CHP / DMCA molar ratio of 1.2:1 (wherein the CHP mass concentration was 70%, relative to the total weight of CHP and cumene solvent being 100%) was pumped into the reactor at a space velocity of 7 L / h / L·cat. After 20 h of reaction, liquid chromatography analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 99.56%, the selectivity for phenol was 0.24%, the selectivity for α-methylstyrene was 0.06%, and the selectivity for acetone was 0.14% (based on CHP). After continuous operation for 1400 h, further sampling and analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 98.95%, the selectivity for phenol was 0.31%, the selectivity for α-methylstyrene was 0.56%, and the selectivity for acetone was 0.18% (based on CHP).

[0083]

Application Example 6

[0084] 50 ml of catalyst F was added to the reactor, and the temperature was raised to 60 °C. After the system stabilized, a cumene solution with a CHP / DMCA molar ratio of 0.8:1 (wherein the CHP mass concentration was 80%, relative to the total weight of CHP and cumene solvent being 100%) was pumped into the reactor at a space velocity of 10 L / h / L·cat. After reacting for 10 h, liquid chromatography analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 99.47%, the selectivity for phenol was 0.11%, the selectivity for α-methylstyrene was 0.12%, and the selectivity for acetone was 0.3% (based on CHP). After continuous operation for 1250 h, further sampling and analysis showed that the feed conversion rate was 100.0%, the selectivity for dicumene peroxide was 98.81%, the selectivity for phenol was 0.21%, the selectivity for α-methylstyrene was 0.42%, and the selectivity for acetone was 0.56% (based on CHP).

[0085] [Application Comparison Example 1]

[0086] Dicumyl peroxide was synthesized using essentially the same method as in Application Example 1, except that catalyst A filled into the reactor was replaced with catalyst A-1.

[0087] After 10 hours of reaction, liquid chromatography analysis showed a feed conversion rate of 100.0%, with selectivity of 83.82% for dicumyl peroxide, 3.58% for phenol, 10.25% for α-methylstyrene, and 2.35% for acetone (based on CHP). After 500 hours of continuous operation, further analysis showed a feed conversion rate of 90.0%, with selectivity of 75.12% for dicumyl peroxide, 5.98% for phenol, 15.35% for α-methylstyrene, and 3.55% for acetone (based on CHP).

[0088] [Application Comparison Example 2]

[0089] Dicumyl peroxide was synthesized using essentially the same method as in Application Example 1, except that catalyst A filled into the reactor was replaced with catalyst A-2.

[0090] After 15 hours of reaction, liquid chromatography analysis showed a 100.0% conversion rate of the raw material, with selectivity of 88.31% for dicumyl peroxide, 2.68% for phenol, 5.78% for α-methylstyrene, and 3.23% for acetone (based on CHP). After 800 hours of continuous operation, further analysis showed a 100.0% conversion rate of the raw material, with selectivity of 78.31% for dicumyl peroxide, 6.78% for phenol, 10.34% for α-methylstyrene, and 4.57% for acetone (based on CHP).

[0091] [Application Comparison Example 3]

[0092] Dicumyl peroxide was synthesized using essentially the same method as in Application Example 1, except that catalyst A filled into the reactor was replaced with catalyst A-3.

[0093] After 20 hours of reaction, liquid chromatography analysis showed a 100.0% conversion rate of the raw material, a 91.91% selectivity for dicumyl peroxide, a 3.54% selectivity for phenol, a 2.68% selectivity for α-methylstyrene, and a 1.87% selectivity for acetone (based on CHP). After 1000 hours of continuous operation, further analysis showed a 100.0% conversion rate of the raw material, a 86.12% selectivity for dicumyl peroxide, a 5.46% selectivity for phenol, a 6.25% selectivity for α-methylstyrene, and a 2.17% selectivity for acetone (based on CHP).

[0094] [Application Comparison Example 4]

[0095] Dicumyl peroxide was synthesized using essentially the same method as in Application Example 1, except that catalyst A filled into the reactor was replaced with catalyst A-4.

[0096] After 15 hours of reaction, liquid chromatography analysis showed a feed conversion rate of 95.0%, a selectivity of 86.32% for dicumyl peroxide, 5.67% for phenol, 4.87% for α-methylstyrene, and 3.14% for acetone (based on CHP). After 600 hours of continuous operation, further analysis showed a feed conversion rate of 85.0%, a selectivity of 76.91% for dicumyl peroxide, 10.24% for phenol, 8.67% for α-methylstyrene, and 4.18% for acetone (based on CHP).

[0097] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a composite catalyst, characterized in that, Weigh 100g of zinc oxide support and add it to 100ml of aqueous solution containing 4.0g of copper chloride using the equal volume impregnation method. After adsorption equilibrium is reached, dry it at 130℃ for 6h and calcine it at 400℃ for 4h under nitrogen atmosphere to obtain the co-catalyst. 50g of ZSM-5 with Si / Al = 70 and 50g of the above-mentioned co-catalyst were added to a mortar and mixed evenly. After grinding and sieving, a mixture was obtained. Then, the mixture was transferred to a crucible and dried at 130°C for 6 hours. After calcination at 500°C for 8 hours under a nitrogen atmosphere, the composite catalyst was obtained by pressing into tablets.

2. The application of a composite catalyst prepared by the method of claim 1 in the synthesis of alkyl peroxides.

3. A method for preparing dicumyl peroxide, characterized in that, In a fixed-bed reactor, cumene peroxide and dimethylbenzyl alcohol are used as raw materials, and a condensation reaction occurs under the action of the composite catalyst prepared by the method described in claim 1 to obtain dicumene peroxide.

4. The method for preparing dicumyl peroxide according to claim 3, characterized in that, The cumene peroxide, dimethyl benzyl alcohol, and solvent are mixed and then fed into the feed, with a total feed space velocity of 1-10 L / h / L·cat.

5. The method for preparing dicumyl peroxide according to claim 4, characterized in that, The cumene peroxide, dimethyl benzyl alcohol, and solvent are mixed and then fed into the feed, with a total feed space velocity of 3-7 L / h / L·cat.

6. The method for preparing dicumyl peroxide according to claim 4, characterized in that, The cumene peroxide, dimethyl benzyl alcohol, and solvent are mixed and then fed into the feed, with a total feed space velocity of 4-6 L / h / L·cat.

7. The method for preparing dicumyl peroxide according to claim 4, characterized in that, The molar ratio of cumene peroxide and dimethyl benzyl alcohol is (0.8-1.2):

1.

8. The method for preparing dicumyl peroxide according to claim 7, characterized in that, The molar ratio of cumene peroxide and dimethyl benzyl alcohol is (0.9-1.1):

1.

9. The method for preparing dicumyl peroxide according to claim 7, characterized in that, The molar ratio of cumene peroxide and dimethyl benzyl alcohol is (1.0-1.05):

1.

10. The method for preparing dicumyl peroxide according to claim 4, characterized in that, The mass concentration of cumene peroxide is 40-80 wt%, based on a total mass of cumene peroxide and solvent of 100 wt%.

11. The method for preparing dicumyl peroxide according to claim 10, characterized in that, The mass concentration of cumene peroxide is 50-70 wt%, based on a total mass of cumene peroxide and solvent of 100 wt%.

12. The method for preparing dicumyl peroxide according to claim 10, characterized in that, The mass concentration of cumene peroxide is 55-65 wt%, based on a total mass of cumene peroxide and solvent of 100 wt%.

13. The method for preparing dicumyl peroxide according to claim 4, characterized in that, The reaction temperature for the condensation reaction is 30-60℃.

14. The method for preparing dicumyl peroxide according to claim 13, characterized in that, The reaction temperature for the condensation reaction is 40-50℃.

15. The method for preparing dicumyl peroxide according to claim 13, characterized in that, The reaction temperature for the condensation reaction is 43-47℃.