A catalyst for the indirect preparation of cyclohexanol from cyclohexene and a process for its preparation

Abstract

This invention discloses a catalyst for the indirect preparation of cyclohexene from cyclohexene and its preparation method. ZSM-5, which has undergone alkali treatment to form a hierarchical porous structure, is used as a support, and the catalyst is sequentially passed through Co anchoring and in-situ MnO. x Nanocluster deposition constructs composite active centers, thereby achieving synergistic regulation of acidity and redox functions, resulting in a Co-Mn@ZSM-5 catalyst. Applying the Co-Mn@ZSM-5 catalyst to the esterification and subsequent hydrogenolysis of cyclohexene and acetate significantly improves the conversion rate of cyclohexene and the selectivity of the intermediate products cyclohexyl acetate and cyclohexanol, while effectively suppressing byproduct formation and metal sintering. This invention provides a novel, efficient, economical, and sustainable catalytic system for the indirect preparation of cyclohexanol from cyclohexene.

Description

Technical Field

[0001] This invention belongs to the field of molecular sieve-based catalyst preparation technology, specifically relating to a catalyst for the indirect preparation of cyclohexanol from cyclohexene and its preparation method. Background Technology

[0002] Cyclohexanol is a crucial raw material in the chemical industry, primarily used in the production of adipic acid, hexamethylenediamine, cyclohexanone, and caprolactam, holding a core position in the nylon and engineering plastics industrial chain. Simultaneously, cyclohexanol also has wide applications in the fine chemical field, serving as a soap stabilizer, paint admixture, leather degreasing agent, dry cleaning agent, and component of various resins and solvents. Current industrial production routes for cyclohexanol include cyclohexene hydration, phenol hydrogenation, and cyclohexane oxidation. Among these, phenol hydrogenation has high energy consumption, and cyclohexane oxidation has low single-pass conversion rates and insufficient safety and environmental friendliness. Cyclohexene hydration, due to its advantages of low hydrogen consumption, fewer byproducts, and a greener process, is gradually becoming a more promising technological route. This method can be further divided into direct hydration and indirect methods. Direct hydration suffers from low cyclohexene conversion rates; therefore, indirect methods, with their high selectivity, high rate, and mild conditions resulting from two-step reactions such as "etherification-hydrolysis" or "esterification-hydrogenation," have attracted considerable attention.

[0003] CN103232325B discloses a method for preparing cyclohexanol from cyclohexene via esterification with carboxylic acids, followed by transesterification. This method improves the overall conversion rate of cyclohexene to some extent. However, the transesterification reaction is still reversible, and the reaction equilibrium is greatly affected by the amount of alcohol used and the formation of by-product esters. It typically requires excess alcohol and complex distillation operations to drive the reaction, resulting in a complex process and high energy consumption. Furthermore, different cyclohexanyl carboxylic acids exhibit significant differences in reactivity, placing high demands on catalyst performance and stability, thus limiting process adaptability and further industrial applications. Since its initial report by Mobil in 1972, ZSM-5 molecular sieve has been widely used in catalytic systems for the hydration of cyclohexene to cyclohexanol due to its unique microporous structure, high specific surface area, moderate acidity, and excellent hydrothermal stability. The application of ZSM-5 has significantly improved the conversion rate of cyclohexene and the selectivity of cyclohexanol, but problems remain, such as uneven distribution of acidic centers leading to increased side reactions, a single pore structure limiting mass transfer, and the tendency of metal components to migrate and aggregate during metal modification, resulting in a shortened lifetime. Especially in indirect preparation methods such as "esterification-hydrogenolysis" of cyclohexene and acetic acid, existing ZSM-5-based catalysts have difficulty simultaneously possessing strong acidic sites and stable and efficient hydrogenolysis / redox functions, which has become a key technical bottleneck limiting the high selectivity and high yield of cyclohexanol.

[0004] To overcome these limitations, researchers have explored various ZSM-5 optimization strategies, including metal doping, desilication pore formation, alkali treatment modification, and composite oxide loading. However, problems remain, such as insufficient metal dispersion, difficulty in controlling pore structure, complex preparation processes, and poor environmental friendliness, making it difficult to meet the requirements of indirect methods for highly efficient bifunctional catalysts. Therefore, it is necessary to develop a ZSM-5-based catalyst that combines controllable acidity, hierarchical pore structure, high redox efficiency, and excellent stability to simultaneously promote the two key steps of esterification and hydrogenolysis, thereby improving cyclohexene conversion, cyclohexanol selectivity, and catalyst lifetime. Summary of the Invention

[0005] This invention provides a catalyst and a method for indirectly preparing cyclohexanol from cyclohexene. The catalyst is a Co-Mn@ZSM-5 catalyst, which exhibits high activity, high selectivity, and excellent stability, making it suitable for the industrial production of cyclohexanol by esterification of cyclohexene with acetic acid followed by hydrogenolysis.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing a catalyst for the indirect preparation of cyclohexene from cyclohexene: using ZSM-5 with a hierarchical porous structure formed by alkali treatment as a support, and sequentially passing it through Co anchoring and in-situ MnO. x Nanoclusters are deposited to construct composite active centers, thereby achieving synergistic regulation of acidity and redox functions to obtain the Co-Mn@ZSM-5 catalyst. The specific steps include:

[0008] (1) Add ZSM-5 molecular sieve to a 0.1-0.5 mol / L alkaline solution and heat at 25-60 °C. o React at C for 5-30 min to allow partial desilication, then wash until neutral and dry to obtain hierarchical porous ZSM-5 molecular sieve with micro / mesoporous synergistic structure, denoted as Hie-ZSM-5 molecular sieve;

[0009] (2) Add Hie-ZSM-5 molecular sieve to deionized water, add 0.5-2.0% of soft template agent by mass of Hie-ZSM-5 molecular sieve, and add Co(NO3)2 solution dropwise by pulse injection method to make the Co / (SiO2) molar ratio 0.001-0.02. Stir for 1-2 h to form atomically dispersed Co anchoring sites and obtain product A.

[0010] (3) Add KMnO4 solution dropwise to the above reaction system, control the pH between 8 and 10, and grow MnO4 in situ with a gradient distribution and a size of 1-5 nm. x Cluster, yielding product B;

[0011] (4) Filter product B at 80-120 °C. o Drying at C for 6-12 hours, or in an N2 atmosphere at 300-450°C. o Calcination at C for 2-4 hours, followed by oxidation in air for 2-4 hours, to stabilize the metal oxidation state and form a highly dispersed Co-O-Mn interface, yielding product C;

[0012] (5) Dissolve product C in 1 mol / L NH4NO3 solution at 75-85°C. o Exchange at C for 3.5-4.5 hours, repeat 3 times, at 450-550°C. o The Co-Mn@ZSM-5 catalyst was obtained by calcination at C for 3-4 h.

[0013] The ZSM-5 molecular sieve described in step (1) is synthesized via a hydrothermal method. A silicon source, an aluminum source, and water are mixed in a specific molar ratio to form a homogeneous gel. After adding seed crystals and aging, the gel is transferred to a reaction vessel for crystallization. The resulting product is then separated, washed, dried, and calcined. The molar ratio of the synthesis system is: n(SiO2) / n(Al2O3) = 25-45, n(H2O) / n(SiO2) = 15-30, the amount of seed crystals added is 1-10 wt% of SiO2, and the crystallization temperature is 160-180 °C. o C, crystallization time is 24-48 h.

[0014] The alkaline solution mentioned in step (1) is at least one of ammonia, potassium hydroxide, or sodium hydroxide.

[0015] The ratio of ZSM-5 molecular sieve to alkaline solution in step (1) is 1g:20-60 mL.

[0016] The soft template agent mentioned in step (2) is at least one of cellulose, sodium alginate or chitosan.

[0017] The ratio of Hie-ZSM-5 molecular sieve to deionized water in step (2) is 1g:20-40mL.

[0018] The amount of KMnO4 solution added in step (3) satisfies the following condition: the Co / Mn molar ratio is 1:(5-10).

[0019] The concentration of the NH4NO3 solution in step (5) is 1 mol / L, and the ratio of product C to NH4NO3 solution is 1 g: 10-30 mL.

[0020] In the prepared Co-Mn@Hie-ZSM-5 catalyst, the Co loading is 0.1-0.5 wt% and the Mn loading is 1-3 wt%.

[0021] The specific surface area of ​​the Co-Mn@Hie-ZSM-5 catalyst is 400-550 m². 2 / g, mesoporous pore volume 0.2-0.3 cm³ 3 / g.

[0022] This invention also relates to the application of the Co-Mn@ZSM-5 catalyst in the preparation of cyclohexanol by hydrogenolysis after cyclohexene esterification. The cyclohexene conversion rate is not less than 98%, and the cyclohexanol selectivity is not less than 90%.

[0023] The present invention has the following beneficial effects:

[0024] The Co-Mn@ZSM-5 catalyst of this invention is based on alkali-treated ZSM-5 molecular sieves, and is anchored to MnO by Co. x The nanoclusters were prepared using a synergistic construction strategy, achieving a spatial gradient distribution of acidic and redox centers within the micro-mesoporous composite channels of the molecular sieve. Co primarily modulates Lewis acid sites and hydrogen transfer capabilities, while MnO... x Nanoclusters impart surface redox activity, and the gradient composite structure formed by the two significantly improves the conversion and selectivity of the esterification-hydrogenolysis reaction of cyclohexene and acetate. Compared with existing synthesis methods, the Co-Mn@ZSM-5 catalyst synthesized in this invention has the following advantages:

[0025] (1) A hierarchical pore structure is constructed by mild alkali treatment to improve molecular diffusion performance;

[0026] (2) Stable anchoring is achieved through natural polysaccharide soft templates, which improves the dispersion of active metals;

[0027] (3) Using in-situ MnO x Deposition achieves a redox activity gradient distribution, enhancing the synergistic effect of dual functions;

[0028] (4) The preparation process is simple and controllable, avoiding the use of organic amine templates and toxic reagents, making it green and environmentally friendly;

[0029] (5) Co-Mn spatially adjacent active centers were constructed by pulse-in-situ stepwise deposition method to synergistically regulate the matching of esterification and hydrogenolysis reactions. By coupling the anchoring effect of Co with the redox properties of Mn, the goal of efficiently preparing cyclohexene from esterification-hydrogenolysis was achieved. The resulting catalyst showed high activity, high selectivity and good stability in the esterification-hydrogenolysis reaction of cyclohexene to cyclohexene. Detailed Implementation

[0030] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials used in the following examples are commercially available products.

[0031] The Co-Mn@ZSM-5 catalyst involved in this invention uses ZSM-5 molecular sieve as raw material, which is alkali-treated to form a hierarchical porous structure, and ZSM-5 as a support. It is then sequentially anchored by Co and subjected to in-situ MnO. x Nanoclusters are deposited to construct composite active centers, thereby achieving synergistic regulation of acidity and redox functions, resulting in Co-Mn@ZSM-5 catalysts.

[0032] The preparation method of ZSM-5 molecular sieve in Example 1 is as follows:

[0033] ZSM-5 molecular sieves are synthesized via a hydrothermal method. A silicon source, an aluminum source, and water are mixed in a specific molar ratio to form a homogeneous gel. Seed crystals are added and the mixture is aged before being transferred to a reaction vessel for crystallization. The resulting product is then separated, washed, dried, and calcined. The molar ratios of the synthesis system are: n(SiO2) / n(Al2O3) = 25-45, n(H2O) / n(SiO2) = 15-30. The seed crystal amount is 1-10 wt% of SiO2, and the seed crystals are purchased ZSM-5 molecular sieve standards. The crystallization temperature is 160-180 °C. o C, crystallization time is 24-48 h.

[0034] Example 1

[0035] Preparation and application of Co-Mn@ZSM-5 catalyst A1

[0036] Step 1: Take 5 g of self-made ZSM-5 molecular sieve (n(SiO2) / n(Al2O3)=45, n(H2O) / n(SiO2)=30), add it to 100 mL of 0.1 mol / L NaOH solution, and heat at 25°C. o React at C for 10 min. After washing with deionized water until neutral, react at 100 °C. o After drying at C for 12 h, partially desilicified hierarchical ZSM-5 molecular sieve was obtained, denoted as Hie-ZSM-5 molecular sieve.

[0037] Step 2: Add the above-mentioned Hie-ZSM-5 molecular sieve to 100 mL of deionized water, add 0.5% sodium alginate (by mass of Hie-ZSM-5 molecular sieve), and dropwise add Co(NO3)2·6H2O aqueous solution using pulse injection method to make the Co / (SiO2) molar ratio 0.001. Stir for 1 h to form atomically Co-anchored Hie-ZSM-5 molecular sieve.

[0038] Step 3: Add KMnO4 solution (Co / Mn molar ratio of 1:5) dropwise to the above system, control the pH to approximately 7, and stir at room temperature for 2 hours to allow the MnO4 solution to form. x Nanoclusters were deposited in situ on the outer surface and mesoporous channels of ZSM-5.

[0039] Step 4: Filter the above-obtained sample and heat it at 80°C. o Drying at C for 8 hours, then drying under N2 atmosphere at 2 o Temperature increased to 300 °C / min o Calcination at C for 2 hours, followed by incubation at 350°C in air. o Oxidation treatment at C for 2 h was performed to stabilize the metal oxidation state and form a highly dispersed Co-O-Mn interface.

[0040] Step 5: Dissolve the calcined sample in 20 mL of 1 mol / L NH4NO3 solution at 80°C. o Ion exchange at C for 2 hours, repeated ion exchange steps 3 times, followed by washing and drying, and then at 500 °C. o Calcination at C for 3 h yielded an H-type low-loaded Co-Mn@ZSM-5 catalyst (Co loading 0.08 wt%, Mn loading 0.09 wt%), with a specific surface area of ​​530 m². 2 / g, mesoporous pore volume 0.23 cm³ 3 / g.

[0041] The catalyst was used in the esterification and subsequent hydrogenolysis of cyclohexene to prepare cyclohexanol. The specific steps are as follows: 10.0 g of cyclohexene, 30.0 g of acetic acid, and 1.0 g of catalyst were added to a sealed high-pressure reactor. N2 was introduced three times to purge air, and the reactor was heated to 80°C. o C. Under 0.3 MPa conditions, the mixture was stirred for 3 h to induce esterification of cyclohexene with acetic acid, forming an intermediate ester. After the reaction was completed, the mixture was cooled to a suitable temperature and then directly transferred to a hydrogenolysis reactor. The atmosphere was changed to hydrogen and purged three times. The reaction was carried out at 130°C. o C. The reaction was continued for 3 h under 2.0 MPa H2 conditions to complete the hydrogenolysis to produce cyclohexanol. After the reaction was completed, the mixture was cooled to room temperature and the pressure was slowly released. The reaction solution was taken out and centrifuged to obtain the liquid product. Gas chromatography analysis showed that the cyclohexene conversion rate reached 99%, the cyclohexanol selectivity was 93%, the cyclohexanol yield was about 92%, and the content of by-products (such as cyclohexane, mild cracking products, etc.) was less than 5%.

[0042] Example 2

[0043] Preparation and application of Co-Mn@ZSM-5 catalyst A2

[0044] In step one, the n(SiO2) / n(Al2O3) ratio of the self-made ZSM-5 molecular sieve was 35, and the other results were the same as in Example 1. The results are shown in Table 1.

[0045] Example 3

[0046] Preparation and application of Co-Mn@ZSM-5 catalyst A3

[0047] In step one, the n(SiO2) / n(Al2O3) ratio of the self-made ZSM-5 molecular sieve was 25, and the other conditions were the same as in Example 1. The results are shown in Table 1.

[0048] Example 4

[0049] Preparation and application of Co-Mn@ZSM-5 catalyst A4

[0050] In step one, the 100 mL of 0.1 mol / L NaOH solution was replaced with 100 mL of 0.3 mol / L sodium hydroxide solution, and the rest was the same as in Example 1. The results are shown in Table 1.

[0051] Example 5

[0052] Preparation and application of Co-Mn@ZSM-5 catalyst A5

[0053] In step one, 100 mL of 0.1 mol / L NaOH solution was replaced with 100 mL of 0.5 mol / L sodium hydroxide solution, and the rest was the same as in Example 1. The results are shown in Table 1.

[0054] Example 6

[0055] Preparation and application of Co-Mn@ZSM-5 catalyst A6

[0056] In step two, KMnO4 solution was added dropwise to the system to make the Co / Mn molar ratio 1:7. Other steps were the same as in Example 1. The results are shown in Table 1.

[0057] Example 7

[0058] Preparation and application of Co-Mn@ZSM-5 catalyst A7

[0059] In step two, KMnO4 solution was added dropwise to the system to make the Co / Mn molar ratio 1:10. Other steps were the same as in Example 1. The results are shown in Table 1.

[0060] Example 8

[0061] Preparation and application of Co-Mn@ZSM-5 catalyst A8

[0062] In step two, an aqueous solution of Co(NO3)2·6H2O was added dropwise using a pulse injection method to make the Co / (SiO2) molar ratio 0.01. Other steps were the same as in Example 1, and the results are shown in Table 1.

[0063] Example 9

[0064] Preparation and application of Co-Mn@ZSM-5 catalyst A9

[0065] In step two, an aqueous solution of Co(NO3)2·6H2O was added dropwise using a pulse injection method to make the Co / (SiO2) molar ratio 0.02. Other steps were the same as in Example 1, and the results are shown in Table 1.

[0066] Example 10

[0067] Preparation and application of Co-Mn@ZSM-5 catalyst A10

[0068] In step two, the soft template agent was changed to chitosan, and the rest was the same as in Example 1. The results are shown in Table 1.

[0069] Example 11

[0070] Preparation and application of Co-Mn@ZSM-5 catalyst Al1

[0071] In step two, the soft template agent was changed to a natural polysaccharide, and the rest was the same as in Example 1. The results are shown in Table 1.

[0072] Example 12

[0073] Preparation and application of Co-Mn@ZSM-5 catalyst Al2

[0074] In step two, the amount of soft template agent added was modified to 1% of the mass of Hie-ZSM-5 molecular sieve, and the rest was the same as in Example 1. The results are shown in Table 1.

[0075] Example 13

[0076] Preparation and application of Co-Mn@ZSM-5 catalyst Al3

[0077] In step two, the amount of soft template agent added was modified to 2% of the mass of Hie-ZSM-5 molecular sieve, and the rest was the same as in Example 1. The results are shown in Table 1.

[0078] Comparative Example 1

[0079] Preparation and application of HZSM-5 catalyst B1

[0080] Without introducing Co and Mn components, only the Hie-ZSM-5 obtained in step one was used, and H-type ZSM-5 was obtained after NH4NO3 ion exchange and calcination. Other aspects were the same as in Example 1, and the results are shown in Table 1.

[0081] Comparative Example 2

[0082] Preparation and application of Co@ZSM-5 catalyst B2

[0083] In step two, Co(NO3)2·6H2O was introduced to make Co / (SiO2)=0.001, and the Mn introduction step was not performed. The remaining steps and reaction conditions were the same as in Example 1. The results are shown in Table 1.

[0084] Comparative Example 3

[0085] Preparation and application of Mn@ZSM-5 catalyst B3

[0086] In step three, KMnO4 was introduced to make Mn / (SiO2)=0.001, and the Co introduction step was not performed. The rest was the same as in Example 1. The results are shown in Table 1.

[0087] Comparative Example 4

[0088] Preparation and application of Co-Mn@ZSM-5 catalyst B4

[0089] Co(NO3)2·6H2O and KMnO4 were introduced simultaneously using an equal-volume impregnation method, so that Co / (SiO2)=0.001 and Mn / (SiO2)=0.001. After drying and calcination, the product was used directly. The remaining reaction conditions were the same as in Example 1. The results are shown in Table 1.

[0090] Comparative Example 5

[0091] Preparation and application of Co-Mn-microporous ZSM-5 catalyst B5

[0092] In step one, no alkali treatment was performed for desilication. Co and Mn were introduced directly using conventional microporous ZSM-5 as a carrier. The remaining steps and reaction conditions were the same as in Example 1. The results are shown in Table 1.

[0093] Table 1. Reaction evaluation results of the catalysts obtained in Examples 1-14 and Comparative Examples 1-5

[0094] catalyst Conversion rate / % Selectivity / % Yield / % By-products / % Example 1 A1 98.5 93.1 92.2 4.6 Example 2 A2 99.2 94.3 93.8 4.2 Example 3 A3 99.4 92.8 89.2 4.7 Example 4 A4 99.2 92.7 91.0 4.6 Example 5 A5 98.9 91.5 89.7 4.4 Example 6 A6 98.7 93.6 92.7 4.5 Example 7 A7 99.4 92.8 90.2 4.7 Example 8 A8 99.3 94.4 93.0 4.3 Example 9 A9 98.7 92.6 91.8 4.5 Example 10 A10 98.9 94.5 93.7 4.4 Example 11 A11 98.1 93.3 92.0 4.2 Example 12 A12 99.2 93.7 92.0 4.6 Example 13 A13 99.4 94.8 93.3 4.7 Comparative Example 1 B1 90.2 82.1 74.1 9.6 Comparative Example 2 B2 91.6 80.4 73.7 10.2 Comparative Example 3 B3 88.9 83.3 74.0 9.1 Comparative Example 4 B4 89.8 79.6 71.5 11.4 Comparative Example 5 B5 92.0 84.2 77.5 8.7

[0095] The reaction results shown in Table 1 reveal that, compared to the examples, Comparative Example 1 did not introduce Co and Mn metal components and relied solely on the acidity of the molecular sieve, lacking effective metal active centers and synergistic hydrogenolysis capabilities. Although this catalyst could promote partial esterification, its hydrogenolysis ability for intermediate esters was significantly insufficient, the reaction pathway was difficult to control effectively, and side reactions increased, resulting in significantly lower selectivity and yield of cyclohexanol compared to the catalysts in the examples.

[0096] Compared to the examples, Comparative Example 2 only introduced Co species without introducing Mn components, making it difficult to form a stable Co-Mn synergistic active structure. The single Co active center has limited ability to regulate the hydrogenolysis reaction, easily leading to over-hydrogenation or non-selective reactions, resulting in increased by-product formation. The selectivity and yield of cyclohexanol are significantly lower than those of the catalysts in the examples.

[0097] Compared with the examples, Comparative Example 3 only introduced Mn species without introducing Co, thus lacking an effective hydrogenolysis active center. Mn mainly acts as an auxiliary or regulator and is difficult to independently undertake the efficient hydrogenolysis reaction of intermediate esters. The reaction conversion efficiency and the ability to generate the target product are limited, and the overall catalytic performance is significantly lower than that of the examples.

[0098] Compared to the examples, Comparative Example 4 used an equal-volume impregnation method to introduce Co and Mn, resulting in poorer metal species dispersion. These metals were prone to aggregation during calcination, making it difficult to form the highly dispersed Co-O-Mn synergistic interface structure seen in the examples. Consequently, the utilization rate of metal active sites was lower, reaction selectivity decreased, and side reactions increased, leading to inferior catalytic activity and stability compared to the examples.

[0099] Compared with the examples, Comparative Example 5 did not subject ZSM-5 to alkali treatment for desilication, and the support remained a single microporous structure. The pore size and connectivity were limited, which was not conducive to the mass transfer and diffusion of reactants and intermediates. At the same time, the metal species were mainly distributed in the micropores or on the outer surface, limiting the synergistic effect and easily causing pore blockage and carbon deposition. As a result, the catalytic activity, selectivity and reusability were significantly lower than those of the examples.

[0100] The above embodiments describe preferred embodiments of the present invention, but the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including combining various technical features in any other way. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a catalyst for the indirect preparation of cyclohexanol from cyclohexene, characterized in that, Includes the following steps: (1) Add ZSM-5 molecular sieve to an alkaline solution and heat at 25-60 °C. o React at C for 5-30 min, then wash the product until neutral and dry to obtain Hie-ZSM-5 molecular sieve; (2) Add Hie-ZSM-5 molecular sieve to water and add soft template agent. Add Co(NO3)2 solution dropwise using pulse injection method to make the Co / (SiO2) molar ratio 0.001-0.

02. Stir for 1-2 h to form atomically dispersed Co anchoring points and obtain product A. (3) Add KMnO4 solution dropwise to the above reaction system, control the pH between 8 and 10, and the reaction yields product B; (4) Filter and dry product B, then heat it in a N2 atmosphere at 300-450°C. o Calcination at C for 2-4 h, followed by oxidation in air for 2-4 h, to stabilize the metal oxidation state and form a highly dispersed Co-O-Mn interface, yielding product C; (5) Dissolve product C in NH4NO3 solution at 75-85°C. o Exchange at C for 3.5-4.5 hours, repeat 3 times, at 450-550°C. o The Co-Mn@ZSM-5 catalyst was obtained by calcination at C for 3-4 h.

2. The method for preparing a catalyst for the indirect preparation of cyclohexanol from cyclohexene according to claim 1, characterized in that, The ZSM-5 molecular sieve described in step (1) is synthesized via a hydrothermal method. A silicon source, an aluminum source, and water are mixed to form a homogeneous gel. Seed crystals are added and the mixture is aged before being transferred to a reaction vessel for crystallization. The resulting product is then separated, washed, dried, and calcined. The molar ratio of the synthesis system is: n(SiO2) / n(Al2O3) = 25~45, n(H2O) / n(SiO2) = 15-30. The amount of seed crystals added is 1-10 wt% of SiO2, and the crystallization temperature is 160-180 °C. o C, crystallization time is 24-48 h.

3. The method for preparing a catalyst for the indirect preparation of cyclohexanol from cyclohexene according to claim 1, characterized in that, The alkaline solution mentioned in step (1) is at least one of ammonia, potassium hydroxide or sodium hydroxide, the concentration of the alkaline solution is 0.1-0.5 mol / L, and the ratio of ZSM-5 molecular sieve to alkaline solution is 1g:20-60 mL.

4. The method for preparing a catalyst for the indirect preparation of cyclohexanol from cyclohexene according to claim 1, characterized in that, The soft template agent mentioned in step (2) is at least one of cellulose, sodium alginate or chitosan, and the amount of soft template agent added is 0.5-2.0% of the mass of Hie-ZSM-5 molecular sieve.

5. The method for preparing a catalyst for the indirect preparation of cyclohexanol from cyclohexene according to claim 1, characterized in that, The ratio of Hie-ZSM-5 molecular sieve to water in step (2) is 1g:20-40mL.

6. The method for preparing a catalyst for the indirect preparation of cyclohexanol from cyclohexene according to claim 1, characterized in that, The amount of KMnO4 solution added in step (3) satisfies the following condition: the Co / Mn molar ratio is 1:5-10.

7. The method for preparing a catalyst for the indirect preparation of cyclohexanol from cyclohexene according to claim 1, wherein the concentration of the NH4NO3 solution in step (5) is 1 mol / L, and the ratio of product C to NH4NO3 solution is 1 g: 10-30 mL.

8. The method for preparing a catalyst for the indirect preparation of cyclohexanol from cyclohexene according to claim 1, wherein the Co-Mn@Hie-ZSM-5 catalyst prepared has a Co loading of 0.1-0.5 wt% and a Mn loading of 1-3 wt%.

9. The method for preparing a catalyst for the indirect preparation of cyclohexanol from cyclohexene according to claim 1, wherein the Co-Mn@Hie-ZSM-5 catalyst has a specific surface area of ​​400-550 m². 2 / g, mesoporous pore volume 0.2-0.3 cm³ 3 / g.

10. The application of the Co-Mn@ZSM-5 catalyst prepared by the method according to any one of claims 1-9 in the preparation of cyclohexene by esterification and subsequent hydrogenolysis to cyclohexanol.