Catalyst for catalyzing benzene to prepare cyclohexylbenzene as well as preparation method and application of catalyst

Abstract

The invention provides a catalyst for catalyzing benzene to prepare cyclohexylbenzene as well as a preparation method and application thereof, the catalyst comprises copper wire light zeolite and active metal loaded in the copper wire light zeolite, and the active metal comprises a nickel element; and the nickel element accounts for 1-7% of the mass of the catalyst. The catalyst provided by the invention takes nickel as an active metal, and the dispersity of the metal nickel can be improved due to the existence of a copper element in the copper wire light zeolite molecular sieve, so that the catalytic activity of the catalyst can be improved, and the conversion rate of benzene and the selectivity of cyclohexylbenzene can be improved when the catalyst is used for catalyzing a hydroalkylation reaction of benzene to generate cyclohexylbenzene.

Description

Technical Field

[0001] The invention belongs to the field of material technology, and in particular relates to a catalyst for preparing cyclohexylbenzene from benzene, and a preparation method and application thereof. Background Art

[0002] Cyclohexylbenzene (CHB), also known as phenylcyclohexane, has a molecular formula of C 12 H 16 It is composed of a three-dimensional cyclohexyl group and a planar benzene ring, and its boiling point is 239℃~240℃. Cyclohexylbenzene is widely used in industry due to its special physical and chemical properties. For example, due to its high boiling point, it is often used as a high boiling point solvent; due to its excellent photochemical properties, it is often used as a raw material for synthesizing liquid crystal materials; in addition, cyclohexylbenzene can also be used as an anti-overcharge protective agent for lithium-ion battery electrolytes to improve the safety and recycling rate of lithium-ion batteries.

[0003] At present, the main routes for synthesizing cyclohexylbenzene include the alkylation of benzene and cyclohexene, the selective hydrogenation of biphenyl, and the hydroalkylation of benzene. Compared with other routes for producing cyclohexylbenzene, the hydroalkylation of benzene has the advantages of simple reaction route, cheap and easy-to-obtain raw materials, and has broad application prospects. However, the hydroalkylation of benzene still has the problems of low benzene conversion rate and low selectivity of cyclohexylbenzene. Summary of the invention

[0004] The main purpose of the present invention is to provide a catalyst for catalyzing benzene to prepare cyclohexylbenzene. When the catalyst catalyzes the benzene hydrogenation alkylation reaction to prepare cyclohexylbenzene, the conversion rate of benzene and the selectivity of cyclohexylbenzene can be improved.

[0005] The present invention also provides a method for preparing a catalyst, which can prepare the above catalyst with simple process and low cost.

[0006] The present invention also provides a method for preparing cyclohexylbenzene, which is obtained by using the above catalyst to catalyze benzene for hydrogenation alkylation reaction, thereby improving the conversion rate of benzene and the selectivity of cyclohexylbenzene.

[0007] In a first aspect, the present invention provides a catalyst for catalyzing benzene to prepare cyclohexylbenzene, comprising copper mordenite and an active metal loaded in the copper mordenite, wherein the active metal comprises nickel element;

[0008] The mass percentage of the nickel element in the catalyst is 1% to 7%.

[0009] In the catalyst as described above, the mass percentage of the nickel element in the catalyst is 5% to 7%.

[0010] The catalyst as described above is prepared by a method comprising the following process:

[0011] The copper-mordenite zeolite is impregnated with a solution containing a nickel source in equal volume, and the obtained impregnation system is subjected to post-treatment including drying and calcination to obtain the catalyst.

[0012] In a second aspect, the present invention provides a method for preparing the catalyst as described above, comprising the following steps:

[0013] 1) dissolving the template in an alkali solution to obtain a first solution;

[0014] 2) adding an aluminum source and a silicon source to the first solution in sequence to obtain a gel mixture;

[0015] 3) adding a copper source to the gel mixture, and performing post-treatment including crystallization treatment, centrifugal treatment, washing treatment, first drying treatment, and first calcination treatment to obtain the copper mordenite;

[0016] 4) using a solution including a nickel source to perform an equal volume impregnation treatment on the copper-mordenite zeolite, and performing a post-treatment including a second drying and a second calcination on the obtained impregnation system to obtain the catalyst.

[0017] In the preparation method of the catalyst as described above, the molar ratio of the copper element in the copper source to the nickel element in the nickel source is (0.5-1):1 (calculated based on the amount of the added metal source).

[0018] The method for preparing the catalyst as described above, wherein the temperature of the crystallization treatment is 120°C to 180°C, and the time is 24h to 48h;

[0019] And / or, the temperature of the first drying treatment is 110°C to 120°C;

[0020] And / or, the temperature of the first calcination treatment is 500° C. to 600° C., and the time is 5 h to 8 h.

[0021] In the catalyst preparation method as described above, the equal volume impregnation treatment is carried out under ultrasound.

[0022] In a second aspect, the present invention provides a method for preparing cyclohexylbenzene, comprising the following steps: using the catalyst as described above or a catalyst prepared by the method for preparing the catalyst as described above to catalyze a hydroalkylation reaction of benzene to obtain cyclohexylbenzene.

[0023] The preparation method of cyclohexylbenzene as described above comprises the following steps:

[0024] 1) activating the catalyst using hydrogen to obtain an activated catalyst;

[0025] 2) At a temperature of 150° C. to 250° C. and a pressure of 1 MPa to 2 MPa, hydrogen and benzene are introduced into a fixed bed containing the activated catalyst for gas-solid contact to carry out the hydroalkylation reaction to obtain the cyclohexylbenzene.

[0026] In the method for preparing cyclohexylbenzene as described above, the molar ratio of hydrogen to benzene is (3-5):1.

[0027] The catalyst for catalyzing benzene to prepare cyclohexylbenzene provided by the present invention uses nickel as an active metal. The presence of copper in the copper-mordenite molecular sieve can improve the dispersibility of the metal nickel, thereby improving the catalytic activity of the catalyst, so that when the catalyst catalyzes the hydrogenation alkylation reaction of benzene to generate cyclohexylbenzene, the conversion rate of benzene and the selectivity of cyclohexylbenzene can be improved. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Cyclohexylbenzene (CHB) is an important chemical intermediate, which is widely used in many industrial fields due to its unique physical and chemical properties. Its high boiling point makes it an ideal high boiling point solvent, suitable for chemical reactions and processes that require high temperature conditions. In addition, the excellent photochemical properties of cyclohexylbenzene make it a key raw material in the synthesis of liquid crystal materials, promoting the development of display technology. More importantly, cyclohexylbenzene can be used as an anti-overcharge protector for electrolytes in the field of lithium-ion batteries, which can effectively improve the safety and cycle life of batteries and meet the needs of modern electronic devices for high-performance batteries.

[0030] Among the many methods for synthesizing cyclohexylbenzene, benzene hydroalkylation has attracted much attention due to its simple reaction route and cheap and readily available raw materials. However, in practical applications, this method still faces the challenges of low benzene conversion rate and low cyclohexylbenzene selectivity, which limits the efficiency and economy of its industrial application.

[0031] The performance of traditional catalysts in the benzene hydroalkylation reaction is not satisfactory. The main reason is that the catalyst activity and selectivity are insufficient, resulting in more by-products and reducing the purity and yield of the target product. Therefore, developing an efficient catalyst to improve the conversion rate of benzene and the selectivity of cyclohexylbenzene has become the focus and difficulty of current research. Copper mordenite as a catalyst carrier, combined with the high catalytic activity of nickel, provides a new idea and method for solving the problems in the existing technology.

[0032] Based on this, in the first aspect, the present invention provides a catalyst for catalyzing benzene to prepare cyclohexylbenzene, comprising copper mordenite and an active metal loaded in the copper mordenite, the active metal comprising nickel element; the mass percentage of nickel element in the catalyst is 1% to 7%, for example, it can be 1%, 2%, 3%, 4%, 5%, 6%, 7% or a range consisting of any two of them.

[0033] It can be understood that copper mordenite is also known as copper mordenite molecular sieve. The mass percentage of nickel in the catalyst provided by the present invention is 1% to 7%. When catalyzing benzene to undergo hydrogenation and alkylation to generate cyclohexylbenzene, the conversion rate of benzene and the selectivity of cyclohexylbenzene can be improved. The reason for the analysis is that nickel, as an active metal in the catalyst, has a high catalytic activity and can effectively promote the selective hydrogenation of carbon-carbon double bonds in the benzene molecule to generate cyclohexene, and cyclohexene and benzene undergo alkylation to generate cyclohexylbenzene; copper mordenite molecular sieve is used as a carrier, in which copper enters the skeleton of the mordenite molecular sieve, and the introduction of copper can inhibit the growth of nickel crystallites during the selective hydrogenation of benzene and the alkylation reaction of cyclohexene and benzene, improve the dispersibility of metal nickel, maintain the active surface area of ​​the catalyst, and thus improve the catalytic activity of the catalyst. Therefore, when the mass percentage of nickel in the catalyst is 1% to 7%, the catalyst has a high catalytic activity, can improve the conversion rate of benzene and the selectivity of cyclohexylbenzene, and helps to reduce energy consumption and production costs, and improve economic benefits. When the mass percentage of nickel in the catalyst is not within the range of 1% to 7%, or copper mordenite molecular sieve is not used as a carrier, the catalyst cannot play such a role, and thus cannot catalyze the hydroalkylation reaction of benzene to produce cyclohexylbenzene or the hydroalkylation reaction of benzene to produce cyclohexylbenzene, the conversion rate of benzene is low, and the selectivity of cyclohexylbenzene is low.

[0034] The catalyst for catalyzing benzene to prepare cyclohexylbenzene provided by the present invention uses nickel as an active metal. The presence of copper in the copper-mordenite molecular sieve can improve the dispersibility of the metal nickel, thereby improving the catalytic activity of the catalyst, so that when the catalyst catalyzes the hydrogenation alkylation reaction of benzene to generate cyclohexylbenzene, the conversion rate of benzene and the selectivity of cyclohexylbenzene can be improved.

[0035] In some embodiments of the present invention, the mass percentage of nickel element in the catalyst is 5% to 7%, for example, it can be 5%, 5.5%, 6%, 6.5%, 7% or any two of them. As a preferred embodiment, the catalytic activity of the catalyst can be further improved, so that when the catalyst catalyzes the hydroalkylation reaction of benzene to produce cyclohexylbenzene, the conversion rate of benzene and the selectivity of cyclohexylbenzene can be further improved.

[0036] In some embodiments of the present invention, the catalyst is prepared by a method comprising the following steps:

[0037] The copper mordenite is impregnated with a solution containing a nickel source in equal volume, and the impregnated system is subjected to post-treatment including drying and calcination to obtain a catalyst.

[0038] In one embodiment, the nickel source can be dissolved in an appropriate amount of water, and completely dissolved under stirring to form a mixed solution, and then an equal volume of copper-mordenite molecular sieve is added to the mixed solution, and the equal volume impregnation treatment is performed for a certain period of time to make the nickel source uniformly dispersed on the copper-mordenite molecular sieve to obtain an impregnation system. The obtained impregnation system is then filtered, washed, dried, and calcined to obtain a copper-mordenite molecular sieve loaded with active component nickel.

[0039] The catalyst preparation method of the present invention can prepare the above catalyst without using precious metals, has simple process, low cost and good industrial application prospect.

[0040] In a second aspect, the present invention provides a method for preparing the catalyst as described above, comprising the following steps:

[0041] 1) dissolving the template in an alkali solution to obtain a first solution;

[0042] 2) adding an aluminum source and a silicon source to the first solution in sequence to obtain a gel mixture;

[0043] 3) adding a copper source to the gel mixture, and performing post-treatment including crystallization treatment, centrifugal treatment, washing treatment, first drying treatment, and first calcination treatment to obtain copper mordenite;

[0044] 4) The copper-mordenite zeolite is impregnated with an equal volume of a solution including a nickel source, and the obtained impregnation system is subjected to post-treatment including a second drying and a second calcination to obtain a catalyst.

[0045] In step 1) of the present invention, the template agent may be an organic amine, preferably tetraethylammonium bromide; the alkali solution may be at least one of an aqueous sodium hydroxide solution and an aqueous potassium hydroxide solution, preferably a sodium hydroxide solution. The template agent tetraethylammonium bromide is added to the prepared sodium hydroxide alkaline solution, and the mixture is fully mixed to obtain a first solution.

[0046] In step 2), the aluminum source may be an aluminum salt, preferably aluminum nitrate; the silicon source may be selected from at least one of silicon dioxide, silicate, silica sol, silica gel, etc., preferably, the silicon source may be silica sol. Aluminum nitrate as the aluminum source is added to the first solution, stirred until completely dissolved, and then silica sol as the silicon source is added, stirred at room temperature, and mixed evenly to obtain a gel mixture.

[0047] In step 3), optionally, the copper source can be a copper salt, preferably, copper nitrate. Dissolve copper nitrate in deionized water to form an aqueous solution containing copper nitrate, i.e., a copper source solution, and then add the copper source solution to the gel mixture obtained above to obtain a gel solution. The gel solution is transferred to a stainless steel reactor containing a polytetrafluoroethylene liner, and the stainless steel reactor is placed in a constant temperature oven for crystallization to make the gel solution crystalline. After the crystallization is completed, the crystallized product is centrifuged, washed with deionized water, first dried, and first calcined in a muffle furnace to obtain a copper mordenite molecular sieve with the template removed.

[0048] In step 4), optionally, the nickel source can be a nickel salt, preferably, nickel nitrate hexahydrate. Nickel nitrate hexahydrate can be dissolved in water and completely dissolved under stirring to form a nickel nitrate hexahydrate solution, and then an equal volume of copper mordenite molecular sieve is added to the nickel nitrate hexahydrate solution, and an equal volume impregnation treatment is performed for a certain period of time to uniformly disperse the metallic nickel on the copper mordenite molecular sieve to obtain an impregnation system. The obtained impregnation system is post-treated to obtain a copper mordenite molecular sieve catalyst loaded with active metallic nickel. The post-treatment includes a second drying and a second calcination treatment. The drying treatment can be carried out in an oven at 100 to 120°C. The second calcination treatment can be carried out in a muffle furnace. The temperature of the second calcination treatment can be 550°C and the time can be 5 hours. It is used to remove volatile components in the copper-silvered zeolite molecular sieve carrier to form a stable structure, so that the molecular sieve carrier obtains a certain crystal form, grain size, pore structure and specific surface area, and obtains a copper-silvered zeolite molecular sieve catalyst loaded with active metal nickel, wherein the mass percentage of nickel element in the catalyst is 1% to 7%.

[0049] The preparation method of the catalyst of the present invention can prepare the catalyst provided by the first aspect of the present invention, and the catalyst can improve the conversion rate of benzene and the selectivity of cyclohexylbenzene. The preparation method is simple and easy to implement and is convenient for industrial scale-up production.

[0050] In some embodiments of the present invention, the molar ratio of the copper element in the copper source to the nickel element in the nickel source is (0.5-1):1, for example, it can be 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1 or a range consisting of any two of them.

[0051] The molar ratio of the copper element in the copper source to the nickel element in the nickel source in the present invention is within the above range, which can produce a synergistic effect, enhance the overall activity of the catalyst, and further improve the conversion rate of benzene and the selectivity of cyclohexylbenzene. In addition, the thermal stability and mechanical strength of the catalyst can also be improved, and the service life of the catalyst can be extended.

[0052] In some embodiments of the present invention, the temperature of the crystallization treatment is 120°C to 180°C, for example, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, or any two thereof. The time of the crystallization treatment is 24h to 48h, for example, 24h, 30h, 35h, 40h, 45h, 48h, or any two thereof.

[0053] In some embodiments, the temperature of the first drying process is 110° C. to 120° C., for example, 110° C., 113° C., 115° C., 118° C., 120° C. or any two thereof.

[0054] In some embodiments, the temperature of the first calcination treatment is 500° C. to 600° C., for example, 500° C., 510° C., 520° C., 530° C., 540° C., 550° C., 560° C., 570° C., 580° C., 590° C., 600° C., or any two thereof. The time of the first calcination treatment is 5 h to 8 h, for example, 5 h, 6 h, 6.5 h, 7 h, 8 h, or any two thereof.

[0055] The temperature and time of the crystallization treatment in the present invention are within the above ranges, which can fully crystallize the gel solution, avoid the crystallization temperature being too low, resulting in incomplete crystallization, and avoid the decomposition of certain substances due to excessively high temperature, which will have a certain impact on the structure of the crystallized product obtained by the crystallization treatment. The temperature and time of the crystallization treatment in the present invention can fully transform the gel solution into a crystallized product with high efficiency.

[0056] In the present invention, the temperature of the drying treatment is within the above range, and moisture on the catalyst surface can be fully removed.

[0057] The temperature and time of the first calcination treatment in the present invention are within the above ranges, which can fully remove the template and volatile components, allow the copper element to fully enter the framework of the mordenite molecular sieve, improve the dispersibility of metallic nickel, thereby improving the catalytic activity of the catalyst, and further improve the conversion rate of benzene and the selectivity of cyclohexylbenzene.

[0058] In some embodiments of the present invention, the equal volume impregnation treatment is performed under ultrasound, that is, ultrasonic impregnation is performed.

[0059] Optionally, the equal volume impregnation treatment can be carried out under ultrasound, and the high frequency vibration of ultrasound can be used to evenly disperse and load the active component, i.e., metallic nickel, onto the copper-mordenite molecular sieve, while overcoming the capillary resistance and entering the pores of the copper-mordenite molecular sieve carrier, thereby improving the catalytic activity of the catalyst, and further improving the conversion rate of benzene and the selectivity of cyclohexylbenzene when benzene is subjected to the hydroalkylation reaction to prepare cyclohexylbenzene.

[0060] In a second aspect, the present invention provides a method for preparing cyclohexylbenzene, comprising the following steps: using the catalyst as described above or a catalyst prepared by the method for preparing the catalyst as described above to catalyze a hydroalkylation reaction of benzene to obtain cyclohexylbenzene.

[0061] The present invention utilizes the catalyst provided in the first aspect or the catalyst prepared by the preparation method provided in the second aspect to catalyze benzene for hydrogenation alkylation reaction to obtain cyclohexylbenzene, thereby improving the conversion rate of benzene and the selectivity of cyclohexylbenzene.

[0062] In some embodiments, the temperature of the hydroalkylation reaction may be 150°C to 250°C, and the pressure may be 1MPa to 2MPa. Exemplarily, the temperature of the hydroalkylation reaction may be 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, or a range consisting of any two of them. The pressure of the hydroalkylation reaction may be 1MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, 1.5MPa, 1.6MPa, 1.7MPa, 1.8MPa, 1.9MPa, 2MPa, or a range consisting of any two of them. The reaction temperature and time may improve the conversion rate of benzene and the selectivity of cyclohexylbenzene when the catalyst catalyzes the hydroalkylation reaction of benzene to obtain cyclohexylbenzene.

[0063] In some embodiments of the present invention, the method for preparing cyclohexylbenzene comprises the following steps:

[0064] 1) activating the catalyst with hydrogen to obtain an activated catalyst;

[0065] 2) At a temperature of 150° C. to 250° C. and a pressure of 1 MPa to 2 MPa, hydrogen and benzene are introduced into a fixed bed containing an activated catalyst for gas-solid contact to carry out a hydroalkylation reaction to obtain cyclohexylbenzene.

[0066] In the present invention, hydrogen is first used to activate the catalyst to obtain an activated catalyst, and then the activated catalyst is used to carry out a hydrogenation alkylation reaction on benzene to obtain cyclohexylbenzene.

[0067] In some embodiments, the temperature of the activation treatment may be 200° C. to 400° C., and the time of the activation treatment may be 1 h to 3 h. For example, the temperature of the activation treatment may be 200° C., 250° C., 300° C., 350° C., 400° C., or a range consisting of any two thereof. The time of the activation treatment may be 1 h, 1.5 h, 2 h, 2.5 h, 3 h, or a range consisting of any two thereof.

[0068] Specifically, in step 1), the catalyst is activated by using hydrogen at 200°C to 400°C for 1h to 3h under the protection of an inert gas, such as nitrogen, to obtain an activated catalyst. It can be understood that after the catalyst is prepared, it is often necessary to activate it to convert the passive catalyst into an activated catalyst. The purpose of activation is to form active sites required for the catalytic reaction on the catalyst, especially on the catalyst surface.

[0069] In step 2), a certain amount of activated catalyst, for example 0.5 g, is loaded into a fixed bed reaction tube, wherein the reaction tube of the fixed bed reaction device has an inner diameter of 10 mm and a length of 40 cm, and then the temperature of the fixed bed is adjusted to a range of 150° C. to 250° C., and the reaction raw materials hydrogen and benzene are introduced for gas-solid contact to carry out a hydroalkylation reaction, and the pressure is controlled within a range of 1 MPa to 2 MPa. Under the action of the catalyst, the carbon-carbon double bonds in the benzene molecules are selectively hydrogenated to produce cyclohexene, and the cyclohexene and benzene undergo an alkylation reaction to produce cyclohexylbenzene.

[0070] The present invention uses the copper-mordenite molecular sieve catalyst loaded with metal nickel to catalyze benzene for hydrogenation alkylation reaction to obtain cyclohexylbenzene. The catalyst has high activity, so the conversion rate of benzene and the selectivity of cyclohexylbenzene can be improved. After the reaction is completed, the catalyst is easy to separate, has little pollution, and is easy to be applied to industrial production.

[0071] In some embodiments of the present invention, the molar ratio of hydrogen to benzene is (3-5):1, for example, it can be 3:1, 3.5:1, 4:1, 4.5:1, 5:1 or a range consisting of any two thereof.

[0072] In the present invention, the molar ratio of hydrogen to benzene is within the above range, so that benzene and hydrogen can fully react to finally generate cyclohexylbenzene, which can further improve the conversion rate of benzene and the selectivity of cyclohexylbenzene.

[0073] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0074] Example 1

[0075] The preparation method of the catalyst of this embodiment comprises the following steps:

[0076] 1) First, 11g of sodium hydroxide was dissolved in 800g of deionized water to prepare a sodium hydroxide solution, and then 3.7g of tetraethylammonium bromide was dissolved in the sodium hydroxide solution, and 12g of aluminum nitrate was added. After stirring and dissolving completely, 400g of silica sol was added, and the mixture was mixed evenly to form a gel mixture. 70g of a 20% copper nitrate solution was added to the gel mixture, and after stirring evenly, it was transferred to a stainless steel reactor lined with polytetrafluoroethylene, and placed in a constant temperature oven at 160°C for crystallization for 36h. After the crystallization was completed, the solid product was centrifuged, washed with deionized water, and subjected to a first drying treatment at 120°C, and subjected to a first calcination treatment at 550°C in a muffle furnace for 8h to obtain 125g of copper mordenite molecular sieve.

[0077] 2) The nickel was loaded on the copper-silvered zeolite molecular sieve carrier by an equal volume impregnation method: 31g Ni(NO3)2·6H2O was dissolved in 60g water, and completely dissolved under stirring, and 125g copper-silvered zeolite molecular sieve was added, wherein the molar ratio of copper element to nickel element was 0.7:1, and ultrasonic impregnation was performed for 2h, filtered, washed, dried at 120°C, and a second calcination treatment was performed at 550°C for 5h to obtain a copper-silvered zeolite catalyst loaded with active component nickel. The mass percentage of nickel element in the catalyst was 5%.

[0078] The preparation method of cyclohexylbenzene of the present embodiment comprises the following steps:

[0079] The above catalyst was activated in H2 atmosphere at 300°C for 1h to obtain an activated catalyst. The reaction tube of the fixed bed reaction device has an inner diameter of 10mm and a length of 40cm. 0.5g of the above activated catalyst was loaded into the reaction tube, the temperature was adjusted to 180°C, and the reaction raw materials hydrogen and benzene were introduced for gas-solid contact to carry out a hydroalkylation reaction, wherein the molar ratio of hydrogen to benzene was 5:1, and the reaction pressure was controlled at 1.5MPa. After the reaction system was stable, the obtained reaction product was cooled and collected and analyzed by gas chromatograph. The results are shown in Table 1.

[0080] Example 2

[0081] The preparation method of the catalyst of Example 2 and Example 1 is basically the same as the preparation method of cyclohexylbenzene, except that in step 2), 43.4g Ni(NO3)2·6H2O is dissolved in 60g water, completely dissolved under stirring, 125g copper mordenite molecular sieve is added, wherein the molar ratio of nickel element to copper element is 0.5:1, ultrasonic impregnation is performed for 2h, filtration, washing, drying at 120°C, and a second calcination treatment is performed at 550°C for 5h to obtain a copper mordenite catalyst loaded with active component nickel. The mass percentage of nickel element in the catalyst is 7%. The temperature of the hydroalkylation reaction is 200°C and the pressure is 2MPa.

[0082] Example 3

[0083] The preparation method of the catalyst of Example 3 and Example 1 is basically the same as the preparation method of cyclohexylbenzene, except that, in step 2), 18.6g Ni(NO3)2·6H2O is dissolved in 60g water, completely dissolved under stirring, 125g copper mordenite molecular sieve is added (12.5g copper nitrate solution with a mass fraction of 20% is added during the synthesis of the molecular sieve), wherein the molar ratio of nickel element to copper element is 1:1, ultrasonic impregnation for 2h, filtration, washing, drying at 120°C, and a second calcination treatment at 550°C for 5h are obtained to obtain a copper mordenite catalyst loaded with active component nickel. The mass percentage of nickel element in the catalyst is 3%. The temperature of the hydroalkylation reaction is 160°C and the pressure is 1MPa.

[0084] Example 4

[0085] The preparation method of the catalyst of Example 4 and Example 1 is basically the same as the preparation method of cyclohexylbenzene, except that, in step 2), 6.2g Ni(NO3)2·6H2O is dissolved in 60g water, completely dissolved under stirring, 125g copper mordenite molecular sieve is added (2g copper nitrate solution with a mass fraction of 20% is added during the synthesis of the molecular sieve), wherein the molar ratio of nickel element to copper element is 0.5:1, ultrasonic impregnation is performed for 2h, filtration, washing, drying at 120°C, and a second calcination treatment is performed at 550°C for 5h to obtain a copper mordenite catalyst loaded with active component nickel. The mass percentage of nickel element in the catalyst is 1%.

[0086] Example 5

[0087] The preparation methods of the catalysts and cyclohexylbenzene in Example 5 and Example 1 are basically the same, except that the temperature of the crystallization treatment in step 1) is 120° C., the time is 48 h, and the temperature of the first drying treatment is 110° C.

[0088] Example 6

[0089] The preparation methods of the catalysts of Example 6 and Example 1 and the preparation method of cyclohexylbenzene are basically the same, except that the temperature of the crystallization treatment in step 1) is 180°C, the time is 24h, and the temperature of the first calcination treatment is 500°C.

[0090] Example 7

[0091] The preparation methods of the catalysts of Example 7 and Example 1 and the preparation method of cyclohexylbenzene are basically the same, except that the temperature of the first calcination treatment in step 1) is 600° C. and the time is 5 hours.

[0092] Example 8

[0093] The preparation methods of the catalysts of Example 8 and Example 1 and the preparation method of cyclohexylbenzene are basically the same, except that the temperature of the hydroalkylation reaction is 250° C., and the molar ratio of hydrogen to benzene is 3:1.

[0094] Comparative Example 1

[0095] The preparation methods of the catalysts of Comparative Example 1 and Example 1 and the preparation method of cyclohexylbenzene are basically the same, except that the catalyst for preparing cyclohexylbenzene uses copper mordenite molecular sieve, on which no active metal nickel is loaded.

[0096] Comparative Example 2

[0097] The preparation methods of the catalysts of Comparative Example 2 and Example 1 and the preparation methods of cyclohexylbenzene are basically the same, except that nickel is loaded on hydrogen-type mordenite molecular sieve: 31g Ni(NO3)2·6H2O is dissolved in 60g water, completely dissolved under stirring, 125g hydrogen-type mordenite molecular sieve is added, ultrasonically impregnated for 2h, filtered, washed, dried at 120°C, and calcined at 550°C for 5h to obtain a hydrogen-type mordenite catalyst loaded with active component nickel. The mass percentage of nickel element in the catalyst is 5%.

[0098] Comparative Example 3

[0099] The preparation methods of the catalysts of Comparative Example 3 and Example 1 and the preparation methods of cyclohexylbenzene are basically the same, except that copper is loaded on hydrogen-type mordenite molecular sieve: 23.8g Cu(NO3)2·3H2O is dissolved in 60g water, completely dissolved under stirring, 125g hydrogen-type mordenite molecular sieve is added, ultrasonically impregnated for 2h, filtered, washed, dried at 120°C, and calcined at 550°C for 5h to obtain a hydrogen-type mordenite catalyst loaded with active component copper. The mass percentage of copper element in the catalyst is 5%.

[0100] Table 1

[0101]

[0102]

[0103] As can be seen from Table 1, compared with the comparative example, the catalyst for catalyzing benzene to prepare cyclohexylbenzene provided by the present invention uses nickel as the active metal, and the presence of copper in the copper-mordenite molecular sieve can improve the dispersibility of metallic nickel, thereby improving the catalytic activity of the catalyst, so that when the catalyst catalyzes the hydroalkylation reaction of benzene to produce cyclohexylbenzene, the conversion rate of benzene and the selectivity of cyclohexylbenzene can be improved.

[0104] From the comparison between Example 1 and Comparative Examples 1-3, it can be seen that the catalyst for catalyzing the preparation of cyclohexylbenzene from benzene provided by the present invention can improve the conversion rate of benzene and the selectivity of cyclohexylbenzene when catalyzing the hydroalkylation reaction of benzene to produce cyclohexylbenzene.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalyst for catalyzing benzene to prepare cyclohexylbenzene, characterized in that: The invention comprises copper mordenite and an active metal loaded in the copper mordenite, wherein the active metal comprises nickel element; The mass percentage of the nickel element in the catalyst is 1% to 7%.

2. The catalyst according to claim 1, characterized in that The mass percentage of the nickel element in the catalyst is 5% to 7%.

3. The catalyst according to claim 1 or 2, characterized in that The catalyst is prepared by a method comprising the following steps: The copper-mordenite zeolite is impregnated with a solution containing a nickel source in equal volume, and the obtained impregnation system is subjected to post-treatment including drying and calcination to obtain the catalyst.

4. A method for preparing the catalyst according to any one of claims 1 to 3, characterized in that: The following steps are involved: 1) dissolving the template in an alkali solution to obtain a first solution; 2) adding an aluminum source and a silicon source to the first solution in sequence to obtain a gel mixture; 3) adding a copper source to the gel mixture, and performing post-treatment including crystallization treatment, centrifugal treatment, washing treatment, first drying treatment, and first calcination treatment to obtain the copper mordenite; 4) using a solution including a nickel source to perform an equal volume impregnation treatment on the copper-mordenite zeolite, and performing a post-treatment including a second drying and a second calcination on the obtained impregnation system to obtain the catalyst.

5. The method for preparing the catalyst according to claim 4, characterized in that: The molar ratio of the copper element in the copper source to the nickel element in the nickel source is (0.5-1):

1.

6. The method for preparing the catalyst according to claim 4 or 5, characterized in that: The crystallization treatment temperature is 120°C to 180°C and the time is 24h to 48h; And / or, the temperature of the first drying treatment is 110°C to 120°C; And / or, the temperature of the first calcination treatment is 500° C. to 600° C., and the time is 5 h to 8 h.

7. The method for preparing a catalyst according to any one of claims 4 to 6, characterized in that: The equal volume immersion treatment is performed under ultrasonication.

8. A method for preparing cyclohexylbenzene, characterized in that: The method comprises the following steps: using the catalyst described in any one of claims 1 to 3 or the catalyst prepared by the preparation method of the catalyst described in any one of claims 4 to 7 to catalyze benzene for hydrogenation alkylation reaction to obtain cyclohexylbenzene.

9. The method for preparing cyclohexylbenzene according to claim 8, characterized in that: The preparation method comprises the following steps: 1) activating the catalyst using hydrogen to obtain an activated catalyst; 2) At a temperature of 150° C. to 250° C. and a pressure of 1 MPa to 2 MPa, hydrogen and benzene are introduced into a fixed bed containing the activated catalyst for gas-solid contact to carry out the hydroalkylation reaction to obtain the cyclohexylbenzene.

10. The method for preparing cyclohexylbenzene according to claim 9, characterized in that: The molar ratio of hydrogen to benzene is (3-5):1.

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