Preparation method of catalyst for improving benzene hydrogenation reaction performance and obtained product

Abstract

The invention belongs to the field of catalytic chemistry, and particularly relates to a preparation method of a catalyst for improving benzene hydrogenation reaction performance and an obtained product. The method is realized by the following steps: (1) adding a sodium hydroxide solution, sodium metaaluminate, silica sol and a transition metal salt solution, then slowly dropwise adding 2-hydroxyethylamine into the mixed solution, aging and drying to obtain a transition metal doped aluminosilicate carrier; and (2) adding the transition metal doped aluminosilicate carrier into the transition metal salt solution II, carrying out equivalent-volume impregnation, heating and stirring, filtering after impregnation, drying, and roasting to obtain the catalyst. The prepared catalyst has higher benzene conversion rate and cyclohexane yield, the performance of benzene hydrogenation reaction is improved, the production cost is reduced, and the catalyst has a positive effect on environmental protection. In addition, the catalyst for improving the benzene hydrogenation reaction performance can also be applied to other organic hydrogenation reactions, and has wide applicability and market prospects. Therefore, the method has high practical value and popularization significance in catalytic chemistry, organic synthesis and related fields.

Description

Technical Field

[0001] The invention belongs to the field of catalytic chemistry, and in particular relates to a preparation method of a catalyst for improving the performance of benzene hydrogenation reaction and the obtained product. Background Art

[0002] Benzene hydrogenation plays an important role in the field of organic chemical industry. Its products, such as cyclohexane and cyclohexene, are widely used in industries such as plastics, rubber, fiber and coatings. However, due to the aromatic structure of benzene, it has high stability and reaction difficulty, which leads to certain limitations of traditional catalysts in the hydrogenation process. These catalysts often show low conversion rate and yield, as well as poor stability, which limits the industrial application of benzene hydrogenation.

[0003] In recent years, with the strengthening of environmental awareness and the improvement of resource utilization efficiency, the development of efficient and environmentally friendly benzene hydrogenation catalysts has become an important direction of scientific research. The design and preparation of catalysts are the key to improving the performance of benzene hydrogenation reactions, including the selection of suitable carriers, active components and additives. The carrier not only provides dispersion and support for the active components, but also affects the surface area, pore structure and thermal stability of the catalyst; the active components directly participate in the reaction, and their type and content have a decisive effect on the reaction performance; the additives further improve the activity and stability of the catalyst by regulating the electronic state of the catalyst surface and improving its anti-sintering performance.

[0004] On this basis, researchers continue to explore new catalyst preparation methods in order to improve the performance of benzene hydrogenation reactions while reducing costs and reducing environmental burdens. Therefore, developing an efficient and stable benzene hydrogenation catalyst is of great significance to improving the performance of organic synthesis reactions. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a method for preparing a catalyst that is efficient, stable and environmentally friendly and improves the performance of benzene hydrogenation reaction by optimizing the composition, structure and preparation process of the catalyst.

[0006] The present invention also provides a catalyst prepared by the above method for improving the performance of benzene hydrogenation reaction.

[0007] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: The present invention provides a method for preparing a catalyst for improving the performance of benzene hydrogenation reaction, comprising the following steps: (1) sodium hydroxide solution, sodium aluminate, silica sol and transition metal salt solution are added, and 2-hydroxyethylamine is slowly added to the mixture, stirred evenly and then heated for aging. After the aging is completed, the temperature is continued to be raised for reaction. After the reaction is completed, the mixture is filtered and dried to obtain a transition metal-doped aluminosilicate carrier; (2) Add the transition metal-doped aluminosilicate carrier into transition metal salt solution II for impregnation in equal volumes, heat and stir, filter after impregnation, dry and calcine to obtain a catalyst.

[0008] Furthermore, in step (1), the mass ratio of sodium hydroxide, sodium aluminate, silica sol and transition metal salt is 1:1:1:1-5:4:1:3; and the amount of 2-hydroxyethylamine added accounts for 1.2-1.5% of the total amount of the mixed solution.

[0009] Furthermore, in step (1), the mass concentration of the sodium hydroxide solution is 5%-40%; the transition metal salt solution is an aqueous solution of one or more of cerium nitrate, zirconium nitrate, iron nitrate, zinc nitrate, copper nitrate, and cobalt nitrate; and the mass concentration of the transition metal salt solution is 5%-30%.

[0010] Furthermore, in step (1), the aging is carried out at 50-100°C for 5-15h; the reaction is carried out at 150-250°C for 10-25h; and the drying is carried out at 60-120°C for 12h.

[0011] Furthermore, in step (2), the mass concentration of the transition metal salt solution II is 5%-30%.

[0012] Furthermore, in step (2), the transition metal salt is one or more of palladium chloride, ruthenium chloride, chromium nitrate, and nickel nitrate.

[0013] Furthermore, in step (2), the stirring is carried out at a temperature of 30-90°C for 5-10 hours; the drying is carried out at a temperature of 60-120°C for 12 hours; the roasting is carried out at 180-200°C for 2-3 hours; and then the temperature is raised to 500-600°C and roasted for 10 hours.

[0014] The present invention also provides a catalyst prepared by the above preparation method for improving the performance of benzene hydrogenation reaction.

[0015] In the preparation process of the catalyst, the carrier is first optimized, cerium oxide, zirconium oxide, iron oxide, etc. are introduced into the aluminosilicate through a doping strategy, and the corresponding stepwise addition is performed to enhance the interaction between the metal and the carrier, thereby obtaining an aluminosilicate carrier with a high specific surface area and a suitable pore size distribution, so as to provide good active component dispersibility and support, and improve the stability of the catalyst under high temperature and high pressure conditions. Then, a transition metal catalyst such as palladium, nickel or cobalt is used as the main active component for impregnation to obtain a high-activity catalyst capable of improving the benzene hydrogenation performance.

[0016] The catalyst of the present invention is not only applicable to benzene hydroalkylation reaction, but also can be extended to other organic hydrogenation reactions, and has wide applicability and market prospects. In addition, while reducing production costs and improving resource utilization efficiency, the present invention is also beneficial to environmental protection and meets the needs of sustainable development. The present invention is expected to produce significant technical and economic benefits in catalytic chemistry, organic synthesis and related fields, and contribute to the development of the organic chemical industry. At the same time, the present invention also provides new ideas and methods for the field of catalyst research, which helps to promote the progress of catalyst preparation technology.

[0017] Compared with the prior art, the present invention has the following advantages: first, the use of a carrier with a high specific surface area and a suitable pore size distribution is conducive to improving the activity of the catalyst; second, the interaction between the metal and the carrier is enhanced by a doping strategy, thereby improving the stability of the catalyst under high temperature and high pressure conditions; third, compared with traditional catalysts, the catalyst prepared by the present invention has a higher benzene conversion rate and cyclohexane yield, improves the performance of the benzene hydrogenation reaction, reduces production costs, and has a positive effect on environmental protection. In addition, the catalyst for improving the performance of the benzene hydrogenation reaction described in the present invention can also be applied to other organic hydrogenation reactions, and has a wide range of applicability and market prospects. Therefore, the present invention has high practical value and promotion significance in catalytic chemistry, organic synthesis and related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the SEM image of the catalyst prepared in Example 1; Figure 2 This is the SEM image of the catalyst prepared in Example 2; Figure 3 This is the SEM image of the catalyst prepared in Example 3; Figure 4 This is the SEM image of the catalyst prepared in Example 4; Figure 5 This is the SEM image of the catalyst prepared in Comparative Example 1; Figure 6 This is the SEM image of the catalyst prepared in Comparative Example 2. DETAILED DESCRIPTION

[0019] Specific implementation method: The following is an example of a method for implementing the present invention.

[0020] The silica sol used in the present invention was purchased from Qingdao Haiwan Fine Chemical Co., Ltd.

[0021] First, sodium hydroxide solution, sodium aluminate, silica sol and one or more transition metal salt solutions such as cerium nitrate, zirconium nitrate, iron nitrate, zinc nitrate, copper nitrate and cobalt nitrate are added into a reaction kettle in a mass ratio of 1:1:1:1-5:4:1:3, and then 2-hydroxyethylamine is slowly added dropwise to the mixed solution, and the mixture is first heated to 50-100°C for aging for 5-15h, and then the temperature is raised to 150-250°C after the aging to react for 10-25h, and after the reaction is completed, the mixture is filtered and dried at 60-120°C for 12h to obtain a transition metal-doped aluminosilicate carrier.

[0022] The doped aluminosilicate carrier is added to a 5%-30% transition metal salt solution of palladium chloride, ruthenium chloride, chromium nitrate, nickel nitrate, etc. for equal volume impregnation, the temperature is raised to 30-90°C, and stirring is performed for 5-10 hours. After the impregnation, it is filtered, dried at 60-120°C for 12 hours, and calcined at 300-600°C for 12 hours to obtain a highly active catalyst.

[0023] The implementation results show that the conversion rate of benzene can be increased by at least 20%, and the yield of the target product can be increased by at least 40% by the method of the present invention. Specifically, under optimized conditions, the conversion rate of benzene can reach more than 80%, and the yield of the target product cyclohexane can reach more than 60%. This embodiment is only used as an example, and the specific embodiment of the present invention can be adjusted according to actual conditions. Without departing from the technical solution of the present invention, the performance of the benzene hydrogenation catalyst can be improved according to the types and proportions of different catalysts, carriers and auxiliary agents, as well as the optimization of reaction conditions. In addition, the method of the present invention can also be applied to other organic hydrogenation reactions and has a wide range of applicability. Through the implementation of the present invention, not only can the performance of the benzene hydrogenation catalyst be improved, the production cost can be reduced, but also it can help to reduce the environmental burden and meet the needs of sustainable development. Therefore, the present invention has high practical value and promotion significance in catalytic chemistry, organic synthesis and related fields.

[0024] Example 1 (1) adding 20% ​​sodium hydroxide solution, sodium aluminate, silica sol and 10% cerium nitrate solution in a mass ratio of 1:1:1:1 to a reaction kettle, mixing well, slowly dropping 1.3% of 2-hydroxyethylamine into the mixture, stirring well, heating to 80°C for aging for 12 hours, heating to 200°C for reaction for 24 hours after aging, filtering after the reaction, and drying at 100°C for 12 hours to obtain a cerium-doped aluminosilicate carrier; (2) The doped aluminosilicate carrier was added to a 10% palladium chloride solution for equal volume impregnation, the temperature was raised to 80°C, and stirring was performed for 10 hours. After the impregnation, the carrier was filtered, dried at 80°C for 12 hours, and treated at 200°C for 2 hours; the temperature was then raised to 500°C and calcined for 10 hours to obtain a catalyst.

[0025] The scanning electron microscopy image of the prepared catalyst is shown in Figure 1 shown.

[0026] Example 2 First, 20% sodium hydroxide solution, sodium aluminate, silica sol and 10% cobalt nitrate solution were added into the reactor in a mass ratio of 1:1:1:1. After mixing evenly, 2-hydroxyethylamine accounting for 1.3% of the total weight of the mixed solution was slowly added dropwise into the mixed solution. After stirring evenly, the mixture was heated to 80°C for aging for 12 hours. After the aging, the mixture was heated to 200°C for reaction for 24 hours. After the reaction, it was filtered and dried at 100°C for 12 hours to obtain a cobalt-doped aluminosilicate carrier.

[0027] The doped aluminosilicate carrier was added to a 10% palladium chloride solution for equal volume impregnation, the temperature was raised to 80°C, and stirring was performed for 10 hours. After the impregnation, it was filtered, dried at 80°C for 12 hours, and treated at 200°C for 2 hours; then the temperature was raised to 500°C and calcined for 10 hours to obtain a catalyst.

[0028] The scanning electron microscopy image of the prepared catalyst is shown in Figure 2 shown.

[0029] Example 3 (1) 20% sodium hydroxide solution, sodium aluminate, silica sol and 10% cerium nitrate solution were added to a reaction kettle in a mass ratio of 3:1:1:3. After mixing evenly, 2-hydroxyethylamine accounting for 1.2% of the total weight of the mixed solution was slowly added dropwise to the mixed solution. After stirring evenly, the mixture was heated to 80°C for aging for 12 hours. After the aging, the mixture was heated to 200°C for reaction for 24 hours. After the reaction, the mixture was filtered and dried at 100°C for 12 hours to obtain a cerium-doped aluminosilicate carrier.

[0030] (3) The doped aluminosilicate carrier was added to a 10% palladium chloride solution for equal volume impregnation, the temperature was raised to 80°C, and the mixture was stirred for 10 hours. After the impregnation, the carrier was filtered, dried at 80°C for 12 hours, and treated at 200°C for 2 hours. The carrier was then heated to 500°C and calcined for 10 hours to obtain a catalyst.

[0031] The scanning electron microscopy image of the prepared catalyst is shown in Figure 3 shown.

[0032] Example 4 (1) 20% sodium hydroxide solution, sodium aluminate, silica sol and 10% cobalt nitrate solution were added to a reaction kettle in a mass ratio of 3:1:1:3. After mixing, 1.2% of 2-hydroxyethylamine was slowly added dropwise to the mixture. After stirring, the mixture was heated to 80°C for aging for 12 hours. After aging, the mixture was heated to 200°C for reaction for 24 hours. After the reaction, the mixture was filtered and dried at 100°C for 12 hours to obtain a cobalt-doped aluminosilicate carrier.

[0033] (2) The doped aluminosilicate carrier was added to a 10% palladium chloride solution for equal volume impregnation, the temperature was raised to 80°C, and stirring was performed for 10 hours. After the impregnation, the carrier was filtered, dried at 80°C for 12 hours, and treated at 200°C for 2 hours; then the temperature was raised to 500°C and calcined for 10 hours to obtain a catalyst.

[0034] The scanning electron microscopy image of the prepared catalyst is shown in Figure 4 shown.

[0035] Comparative Example 1 (1) Add 20% sodium hydroxide solution, sodium aluminate, silica sol and 10% cerium nitrate solution into a reaction kettle in a mass ratio of 1:1:1, heat to 80°C for aging for 12 hours, heat to 200°C for reaction for 24 hours after aging, filter after the reaction, and dry at 100°C for 12 hours to obtain a catalyst.

[0036] The scanning electron microscopy image of the prepared catalyst is shown in Figure 5 shown.

[0037] Comparative Example 2 (1) adding 20% ​​sodium hydroxide solution, sodium aluminate, silica sol and 10% cerium nitrate solution into a reaction kettle in a mass ratio of 1:1:1:1, stirring evenly, heating to 80°C for aging for 12 hours, heating to 200°C for reaction for 24 hours after aging, filtering after the reaction, and drying at 100°C for 12 hours to obtain a cerium-doped aluminosilicate carrier; (2) The doped aluminosilicate carrier was added to a 10% palladium chloride solution for equal volume impregnation, the temperature was raised to 80°C, and stirring was performed for 10 hours. After the impregnation, the carrier was filtered, dried at 80°C for 12 hours, and then heated to 500°C for calcination for 12 hours to obtain a catalyst.

[0038] The scanning electron microscopy image of the prepared catalyst is shown in Figure 6 shown.

[0039] Effect Example The catalysts prepared in Example 1-4 and Comparative Example 1-2 were used for the hydrogenation of benzene to produce cyclohexane. The reaction conditions were benzene / n-hexane: 1:4 (molar ratio) and the device feed rate was 5.0 g·h-1 , the catalyst dosage is 1.485g, hydrogen to benzene ratio: 5.0 (molar ratio), hydrogen pressure: 0.8MPa, activation time: 4h, activation temperature: 550℃, hydrogen flow rate: 10mL·min -1 , airspeed: 1.0h -1 .

[0040] The conversion rate of benzene is calculated as follows: The calculation formula of cyclohexane selectivity is as follows: The calculation formula of cyclohexane yield is as follows: The benzene conversion rate and cyclohexane yield were statistically analyzed. The specific results are shown in Table 1.

[0041] Table 1

Claims

1. A method for preparing a catalyst for improving the performance of benzene hydrogenation reaction, characterized in that: The following steps are involved: (1) sodium hydroxide solution, sodium aluminate, silica sol and transition metal salt solution are added, and 2-hydroxyethylamine is slowly added to the mixture, stirred evenly and then heated for aging. After the aging is completed, the temperature is continued to be raised for reaction. After the reaction is completed, the mixture is filtered and dried to obtain a transition metal-doped aluminosilicate carrier; (2) Add the transition metal-doped aluminosilicate carrier into transition metal salt solution II for impregnation in equal volumes, heat and stir, filter after impregnation, dry and calcine to obtain a catalyst.

2. The preparation method according to claim 1, characterized in that: In step (1), the mass ratio of sodium hydroxide, sodium aluminate, silica sol and transition metal salt is 1:1:1:1-5:4:1:3; and the amount of 2-hydroxyethylamine added accounts for 1.2-1.5% of the total amount of the mixed solution.

3. The preparation method according to claim 1 or 2, characterized in that: In step (1), the mass concentration of the sodium hydroxide solution is 5%-40%; the transition metal salt solution is an aqueous solution of one or more of cerium nitrate, zirconium nitrate, iron nitrate, zinc nitrate, copper nitrate, and cobalt nitrate; the mass concentration of the transition metal salt solution is 5%-30%.

4. The preparation method according to any one of claims 1 to 3, characterized in that In step (1), the aging is carried out at 50-100°C for 5-15h; the reaction is carried out at 150-250°C for 10-25h; and the drying is carried out at 60-120°C for 12h.

5. The preparation method according to claim 1, characterized in that: In step (2), the mass concentration of the transition metal salt solution II is 5%-30%.

6. The preparation method according to claim 1 or 5, characterized in that: In step (2), the transition metal salt is one or more of palladium chloride, ruthenium chloride, chromium nitrate, and nickel nitrate.

7. The preparation method according to claim 1, 5 or 6, characterized in that: In step (2), the stirring is carried out at a temperature of 30-90°C for 5-10 hours; the drying is carried out at a temperature of 60-120°C for 12 hours; the roasting is carried out at 180-200°C for 2-3 hours; and then the temperature is raised to 500-600°C and roasted for 10 hours.

8. A catalyst for improving the performance of benzene hydrogenation reaction, prepared by the preparation method according to any one of claims 1 to 7.

Images