Activation and regeneration preparation process and application of deactivated copper catalyst

Abstract

The invention relates to the technical field of catalyst regeneration, in particular to an activation and regeneration preparation process and application of an inactivated copper catalyst, and the activation and regeneration preparation process comprises the following steps: S1, washing and alkali treatment; s2, cleaning; s3, mixing and filling; s4, functional modification of the modified silica gel; and S5, activating and reducing. Through a unique multi-step treatment process, the regeneration efficiency of the catalyst is greatly improved, and compared with a traditional method, the regeneration time is greatly shortened. Meanwhile, the usage amount of chemical reagents is effectively reduced in the regeneration process, and the production cost is reduced. The activity of the copper catalyst regenerated by the method is remarkably improved, the stability is enhanced, the efficiency of related chemical reactions and the product quality can be remarkably improved, and the method has extremely high industrial application value.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst regeneration, in particular to an activation and regeneration preparation process for a deactivated copper catalyst and an application thereof. Background Art

[0002] Acrylamide is an important chemical raw material, widely used in water treatment, papermaking, textiles, and oil extraction. Copper catalysts are key catalysts in acrylamide production, and their activity and stability directly impact production efficiency and product quality.

[0003] In existing technologies, copper catalysts gradually deactivate during use, resulting in a decrease in hydration catalytic efficiency. Traditional regeneration methods typically involve washing, drying, and activation steps, but these methods present the following challenges: insufficient catalyst activity recovery after regeneration, resulting in low hydration catalytic efficiency; the generation of byproducts during regeneration, which impacts catalyst purity and stability; complex processes, high energy consumption, and high production costs; and the reactivity of the metallic aluminum on the surface of the newly added catalyst, which can react violently with liquid caustic soda to produce an exothermic reaction, posing a safety hazard. Furthermore, the highly concentrated wastewater produced after regeneration is environmentally unfriendly.

[0004] Therefore, it is of great significance to develop an efficient and low-cost copper catalyst regeneration process. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a preparation process for activation and regeneration of deactivated copper catalysts and its application.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A process for preparing an activated and regenerated deactivated copper catalyst comprises the following steps:

[0008] S1 washing and alkali treatment: the newly added copper catalyst was washed with deionized water 4-5 times, and then immersed in a sodium hydroxide solution having a concentration of 5-10% for 18-20h to obtain a pretreated catalyst;

[0009] S2. Cleaning: Soak the pretreated catalyst in deionized water at 60-70 ° C for 18-20h to obtain a dealkalized catalyst;

[0010] S3 mixed filling: The dealkalized catalyst and the deactivated copper catalyst are thoroughly mixed and sequentially loaded into the three-stage reactor for cyclic regeneration operation;

[0011] S4. Functionalization of modified silica gel: adding the modified silica gel to the tertiary reactor after the cyclic regeneration operation for functionalization modification to obtain a modified catalyst;

[0012] S5. Activation and Reduction: Liquid caustic soda is added to the modified catalyst in batches, and the generated hydrogen is reduced with copper oxide at 250-300°C. Activation treatment is then performed at 150-200°C to obtain a regenerated, highly efficient copper catalyst.

[0013] The preparation of modified silica gel includes the following steps:

[0014] S11 silica gel pretreatment: 10-15 parts of mesoporous silica gel was immersed in 50-70 parts of the modified sol and refluxed at 70-80 ° C for 5-6h to obtain a preliminary modified silica gel;

[0015] S12. Ionic liquid grafting: The preliminarily modified silica gel was reacted with 20-40 parts of 1-butyl-3-methylimidazolium tetrafluoroborate in toluene for 10-12 hours, washed with ethanol 3-4 times, and dried under vacuum at 50-60°C to obtain modified silica gel.

[0016] Preferably, the mass ratio of the catalyst after screening in step S3 to the deactivated copper catalyst is 1:2.

[0017] Preferably, the cyclic regeneration operation of step S3 uses sodium hydroxide with an end point concentration of 15% to cyclically regenerate the catalyst loaded in the three-stage reactor. In the initial stage, the sodium hydroxide concentration is 5%, and then the sodium hydroxide concentration is increased by 1% every two hours, and the control time is 20 hours.

[0018] Preferably, the preparation of the modified sol comprises the following steps:

[0019] S111 7-10 parts of 3-aminopropyltriethoxysilane and 2-5 parts of mercaptopropyltrimethoxysilane are dissolved in 90-100 parts of anhydrous ethanol, and 0.1-0.5 parts by mass concentration of 36-38% hydrochloric acid is added as a catalyst;

[0020] S112. Add 0.5-1 parts of the composite nanoparticles to the solution obtained in step S111, stir at a constant temperature of 40-50°C for 4-6 hours to form a uniform sol, and then let it stand and mature for 10-12 hours to obtain a modified sol.

[0021] Preferably, the preparation of the composite nanoparticles comprises the following steps:

[0022] S1121. Lanthanum nitrate and cerium nitrate were mixed and added to a 10-15% ammonia solution and reacted for 1-2h;

[0023] S1122. The solution obtained in step S1121 is washed by centrifugation and dried, and calcined at 500-600° C. for 3-4 hours to obtain composite nanoparticles.

[0024] Preferably, the mass ratio of the modified silica gel to the mixed catalyst obtained in step S3 is 1:5.

[0025] Preferably, the adding of liquid alkali in batches in step S5 is specifically: adding sodium hydroxide solution with a mass concentration of 10-15% in 3-4 times, each time with an interval of 20-30 minutes.

[0026] Preferably, the time for the reduction reaction and activation treatment in step S5 is 2-3 hours and 2-4 hours, respectively.

[0027] Preferably, the mass ratio of lanthanum nitrate to cerium nitrate is 1:3.

[0028] The invention relates to the application of the regenerated high-efficiency copper catalyst prepared according to the above-mentioned activation and regeneration preparation process of a deactivated copper catalyst in the production of acrylamide.

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

[0030] 1. The modified sol prepared by the composite nanoparticles of the present invention can cover the pores on the catalyst surface with a uniform nanocoating. The -Si-O-Si- network formed by the hydrochloric acid-catalyzed hydrolysis of silane in the sol enhances the alkali resistance and anti-swelling ability of the coating, reduces the penetration loss of chemical reagents during the regeneration process, prevents the agglomeration of active components, and increases the oxygen vacancy density, directly promoting the increase in acrylamide yield.

[0031] 2. The present invention forms a hydrophobic-hydrophilic alternating microenvironment on the silica gel surface through the coordinated use of modified silica gel and modified sol. This structure can directionally adsorb reactant molecules, reduce the retention of by-products on the catalyst surface, and optimize the reactant diffusion path, thereby reducing by-product generation by 20%, extending catalyst life by 50%, increasing oxygen vacancy density, and increasing acrylamide yield by 15%.

[0032] 3. This invention significantly improves catalyst regeneration efficiency through a unique multi-step process, significantly shortening regeneration time compared to traditional methods. Furthermore, it effectively reduces the amount of chemical reagents used during the regeneration process, lowering production costs. The copper catalyst regenerated by this method exhibits significantly enhanced activity and stability, significantly improving the efficiency and product quality of related chemical reactions, and possesses high industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a process flow chart of the present invention for improving the hydration catalytic efficiency by improving the copper catalyst activation process;

[0034] Figure 2 This is a flow chart of the preparation process of the modified silica gel of the present invention;

[0035] Figure 3Flow chart of the preparation process of the modified sol of the present invention;

[0036] Figure 4 This is a process flow chart for preparing the composite nanoparticles of the present invention. DETAILED DESCRIPTION

[0037] The present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] See also Figure 1-4 , the present invention provides a technical solution:

[0039] During use, the catalyst's particle size may change due to wear, carbon deposits, and other factors. Screening can remove oversized or undersized particles. Oversized particles may affect the distribution of the fluid within the reactor, leading to an uneven reaction; undersized particles may be lost with the reactants, resulting in catalyst waste. Precise screening ensures that the catalyst particles loaded into the reactor are relatively uniform in size, which helps improve the stability and efficiency of the reaction. For example, in a fixed-bed reactor, uniform particle distribution allows the fluid to flow more smoothly through the catalyst bed, avoiding phenomena such as channeling and ensuring that the reaction can proceed under good mass and heat transfer conditions.

[0040] The mass ratio of the catalyst after screening in step S3 to the deactivated copper catalyst is 1:2, and this mass ratio has been verified by a large number of experiments and actual production experience. Although the activity of the old catalyst has decreased, it still retains certain catalytic active sites and structural characteristics. The newly cleaned catalyst has a higher initial activity. Mixing and loading them in a mass ratio of 1:2 can not only make full use of the residual value of the old catalyst and reduce costs, but also drive the operation of the entire reaction system with the help of the high activity of the new catalyst. For example, in some organic synthesis reactions, the new catalyst can quickly start the reaction, while the old catalyst gradually releases its activity during the reaction to maintain the continuous and stable progress of the reaction. The two work synergistically to achieve a better balance between catalytic effect and economic benefits.

[0041] Liquid alkali (sodium hydroxide) plays a key role in the catalyst regeneration process. The concentration of liquid alkali is controlled at about 5% in the initial stage because the impurities and inactivated substances on the surface of the catalyst require mild conditions for preliminary cleaning and activation. As the temperature of the reactor increases, the activity of the catalyst gradually recovers, and its reaction activity with liquid alkali also increases. Slowly increasing the concentration of liquid alkali to the end point of about 15% can gradually and deeply remove stubborn impurities on the surface of the catalyst, such as carbon deposits, metal oxides, etc., while promoting the re-exposure and recovery of the active sites of the catalyst. For example, for catalysts that have been deactivated due to the adsorption of organic pollutants, low-concentration liquid alkali first dissolves some of the soluble impurities. As the concentration increases, the stronger alkaline environment can destroy the chemical bonds between the organic pollutants and the catalyst surface, completely removing them, thereby effectively restoring the activity of the catalyst.

[0042] Example 1

[0043] A preparation process for activation and regeneration of deactivated copper catalyst:

[0044] Before implementing the improved method, the modified silica gel is prepared:

[0045] S11. Silica gel pretreatment: 20 g of mesoporous silica gel was immersed in 100 g of modified sol and refluxed at 70 ° C for 5 h to obtain a preliminary modified silica gel;

[0046] S12. Ionic liquid grafting: The preliminarily modified silica gel was reacted with 40 g of 1-butyl-3-methylimidazolium tetrafluoroborate in toluene for 10 h, washed three times with ethanol, and dried under vacuum at 50°C to obtain modified silica gel;

[0047] The preparation of the modified sol comprises the following steps:

[0048] S111 70g 3-aminopropyltriethoxysilane and 20g mercaptopropyltrimethoxysilane were dissolved in 900ml of anhydrous ethanol, and 1ml of 36% hydrochloric acid was added as a catalyst;

[0049] S112. 5 g of the composite nanoparticles were added to the solution obtained in step S111 and stirred at a constant temperature of 40 ° C for 4 h to form a uniform sol and then allowed to stand for 10 h to obtain a modified sol;

[0050] The preparation of the composite nanoparticles comprises the following steps:

[0051] S1121. Mix 10g of lanthanum nitrate and 30g of cerium nitrate, add 10% ammonia solution and react for 1h;

[0052] S1122. The solution obtained in step S1121 is washed by centrifugation and dried, and calcined at 500° C. for 3 h to obtain composite nanoparticles;

[0053] S1 washing and alkali treatment: 200g of the newly added copper catalyst was washed four times with deionized water and then immersed in a 5% sodium hydroxide solution for 18h to obtain a pretreated catalyst;

[0054] S2. Cleaning: The pretreated catalyst was immersed in deionized water at 60°C for 18 hours to obtain a dealkalized catalyst;

[0055] S3 mixed loading: The dealkalized catalyst was thoroughly mixed with 400g of deactivated copper catalyst and sequentially loaded into a three-stage reactor for cyclic regeneration operation, using an endpoint concentration of 15% sodium hydroxide to load the catalyst in the three-stage reactor for cyclic regeneration operation, the initial stage, the sodium hydroxide concentration was 5%, then every two hours to increase the sodium hydroxide concentration by 1%, the control time 20h;

[0056] S4 modified silica gel functionalization modification: 120g of modified silica gel was added to the tertiary reactor after the regeneration operation for functional modification to obtain a modified catalyst;

[0057] S5. Activation and reduction: A 10% sodium hydroxide solution was added to the modified catalyst three times, with an interval of 20 minutes between each addition. The generated hydrogen was reduced with copper oxide at 250°C for 2 hours, and then activated at 150°C for 2 hours to obtain a regenerated high-efficiency copper catalyst.

[0058] Example 2

[0059] A preparation process for activation and regeneration of deactivated copper catalyst:

[0060] Before implementing the improved method, the modified silica gel is prepared:

[0061] S11. Silica gel pretreatment: 30 g of mesoporous silica gel was immersed in 140 g of the modified sol and refluxed at 80 ° C for 6 h to obtain a preliminary modified silica gel;

[0062] S12. Ionic liquid grafting: The preliminarily modified silica gel was reacted with 80 g of 1-butyl-3-methylimidazolium tetrafluoroborate in toluene for 12 h, washed four times with ethanol, and dried under vacuum at 60°C to obtain modified silica gel;

[0063] The preparation of the modified sol comprises the following steps:

[0064] S111 100g 3-aminopropyltriethoxysilane and 50g mercaptopropyltrimethoxysilane were dissolved in 1000ml of anhydrous ethanol, and 5ml of 38% hydrochloric acid was added as a catalyst;

[0065] S112. 10 g of the composite nanoparticles were added to the solution obtained in step S111 and stirred at a constant temperature of 50 ° C for 6 h to form a uniform sol and then allowed to stand for 12 h to obtain a modified sol;

[0066] The preparation of the composite nanoparticles comprises the following steps:

[0067] S1121. Mix 10g of lanthanum nitrate and 30g of cerium nitrate, add 15% ammonia solution and react for 2h;

[0068] S1122. The solution obtained in step S1121 is washed by centrifugation and dried, and calcined at 600° C. for 4 h to obtain composite nanoparticles;

[0069] S1 washing and alkali treatment: 200g of the newly added copper catalyst was washed 5 times with deionized water, and then immersed in a 10% sodium hydroxide solution for 20h to obtain a pretreated catalyst;

[0070] S2. Cleaning: The pretreated catalyst was immersed in deionized water at 70 ° C for 20 h to obtain a dealkalized catalyst;

[0071] S3 mixed loading: The dealkalized catalyst was thoroughly mixed with 400g of deactivated copper catalyst and sequentially loaded into a three-stage reactor for cyclic regeneration operation, using an endpoint concentration of 15% sodium hydroxide to load the catalyst in the three-stage reactor for cyclic regeneration operation, the initial stage, the sodium hydroxide concentration was 5%, then every two hours to increase the sodium hydroxide concentration by 1%, the control time 20h;

[0072] S4 modified silica gel functionalization modification: 120g of modified silica gel was added to the tertiary reactor after the regeneration operation for functional modification to obtain a modified catalyst;

[0073] S5. Activation and reduction: A 15% sodium hydroxide solution was added to the modified catalyst in four portions, with an interval of 30 minutes between each addition. The generated hydrogen was reduced with copper oxide at 300°C for 3 hours, and then activated at 200°C for 4 hours to obtain a regenerated, highly efficient copper catalyst.

[0074] Example 3

[0075] A preparation process for activation and regeneration of deactivated copper catalyst:

[0076] Before implementing the improved method, the modified silica gel is prepared:

[0077] S11. Silica gel pretreatment: 22 g of mesoporous silica gel was immersed in 120 g of the modified sol and refluxed at 74 ° C for 5.5 h to obtain a preliminary modified silica gel;

[0078] S12. Ionic liquid grafting: The preliminarily modified silica gel was reacted with 50 g of 1-butyl-3-methylimidazolium tetrafluoroborate in toluene for 11 h, washed three times with ethanol, and dried under vacuum at 54°C to obtain modified silica gel;

[0079] The preparation of the modified sol comprises the following steps:

[0080] S111 80g3-aminopropyltriethoxysilane and 30g mercaptopropyltrimethoxysilane were dissolved in 940ml of anhydrous ethanol, and 2ml of 37% hydrochloric acid was added as a catalyst;

[0081] S112. 7 g of the composite nanoparticles were added to the solution obtained in step S111 and stirred at a constant temperature of 44 ° C for 5 h to form a uniform sol and then allowed to stand for 11 h to obtain a modified sol;

[0082] The preparation of the composite nanoparticles comprises the following steps:

[0083] S1121. Mix 10g of lanthanum nitrate and 30g of cerium nitrate, add 12% ammonia solution and react for 1.5h;

[0084] S1122. The solution obtained in step S1121 is washed by centrifugation and dried, and calcined at 550° C. for 3.5 h to obtain composite nanoparticles;

[0085] S1 washing and alkali treatment: 200g of the newly added copper catalyst was washed four times with deionized water and then immersed in a 7% sodium hydroxide solution for 19h to obtain a pretreated catalyst;

[0086] S2. Cleaning: The pretreated catalyst was immersed in deionized water at 64°C for 19 hours to obtain a dealkalized catalyst;

[0087] S3 mixed loading: The dealkalized catalyst was thoroughly mixed with 400g of deactivated copper catalyst and sequentially loaded into a three-stage reactor for cyclic regeneration operation, using an endpoint concentration of 15% sodium hydroxide to load the catalyst in the three-stage reactor for cyclic regeneration operation, the initial stage, the sodium hydroxide concentration was 5%, then every two hours to increase the sodium hydroxide concentration by 1%, the control time 20h;

[0088] S4 modified silica gel functionalization modification: 120g of modified silica gel was added to the tertiary reactor after the regeneration operation for functional modification to obtain a modified catalyst;

[0089] S5. Activation and reduction: A 12% sodium hydroxide solution was added to the modified catalyst in three portions, with an interval of 24 minutes between each addition. The generated hydrogen was reduced with copper oxide at 270°C for 2.5 hours, and the catalyst was activated at 170°C for 3 hours to obtain a regenerated, highly efficient copper catalyst.

[0090] Example 4

[0091] A preparation process for activation and regeneration of deactivated copper catalyst:

[0092] Before implementing the improved method, the modified silica gel is prepared:

[0093] S11. Silica gel pretreatment: 28 g of mesoporous silica gel was immersed in 130 g of the modified sol and refluxed at 78 ° C for 5.5 h to obtain a preliminary modified silica gel;

[0094] S12. Ionic liquid grafting: The preliminarily modified silica gel was reacted with 70 g of 1-butyl-3-methylimidazolium tetrafluoroborate in toluene for 11 h, washed four times with ethanol, and dried under vacuum at 58°C to obtain modified silica gel;

[0095] The preparation of the modified sol comprises the following steps:

[0096] S111 90g3-aminopropyltriethoxysilane and 40g mercaptopropyltrimethoxysilane were dissolved in 980ml of anhydrous ethanol, and 4ml of 37% hydrochloric acid was added as a catalyst;

[0097] S112 was added 9g of composite nanoparticles to the solution obtained in step S111, stirred at a constant temperature of 58 ° C for 5.5h, and then allowed to stand for 11.5h to form a uniform sol to obtain a modified sol;

[0098] The preparation of the composite nanoparticles comprises the following steps:

[0099] S1121. Mix 10g of lanthanum nitrate and 30g of cerium nitrate, add 14% ammonia solution and react for 1.5h;

[0100] S1122. The solution obtained in step S1121 was washed by centrifugation and dried, and calcined at 580° C. for 3.5 h to obtain composite nanoparticles;

[0101] S1 washing and alkali treatment: 200g of the newly added copper catalyst was washed 5 times with deionized water, and then immersed in a 9% sodium hydroxide solution for 19h to obtain a pretreated catalyst;

[0102] S2. Cleaning: The pretreated catalyst was immersed in deionized water at 68°C for 19 hours to obtain a dealkalized catalyst;

[0103] S3 mixed loading: The dealkalized catalyst was thoroughly mixed with 400g of deactivated copper catalyst and sequentially loaded into a three-stage reactor for cyclic regeneration operation, using an endpoint concentration of 15% sodium hydroxide to load the catalyst in the three-stage reactor for cyclic regeneration operation, the initial stage, the sodium hydroxide concentration was 5%, then every two hours to increase the sodium hydroxide concentration by 1%, the control time 20h;

[0104] S4. Modified silica gel functionalization modification: 120 g of modified silica gel was added to the tertiary reactor after the cyclic regeneration operation for functionalization modification to obtain a modified catalyst;

[0105] S5. Activation and reduction: A 14% sodium hydroxide solution was added to the modified catalyst in four portions, with an interval of 28 minutes between each addition. The generated hydrogen was reduced with copper oxide at 280°C for 2.5 hours, and the catalyst was activated at 180°C for 3.5 hours to obtain a regenerated, highly efficient copper catalyst.

[0106] Comparative Example 1

[0107] The copper catalyst in this comparative example was treated by a traditional regeneration method, that is, only the steps of washing, drying and activation were performed.

[0108] Performance testing:

[0109] In a fixed-bed reactor, the temperature was set at 80° C. and the pressure was 1.5 MPa. An aqueous solution of acrylonitrile having a mass concentration of 20% was used as the reactant. The flow rate was controlled at 50 mL / min. The regenerated high-efficiency copper catalyst obtained in Examples 1-4 and Comparative Example 1 was used as the catalyst. The acrylamide yield after one hour of reaction was recorded. The obtained data are shown in Table 1 below:

[0110] Table 1

[0111] Acrylamide yield (%) Example 1 83.4±0.8 Example 2 84.1±0.7 Example 3 83.8±0.9 Example 4 84.5±0.6 Comparative Example 1 72.5±1.2

[0112] The average acrylamide yield of the examples was 83.9%, which was about 15.7% higher than that of the control group (72.5%). The yield improvement was attributed to the combined use of modified silica gel and modified sol, which increased the oxygen vacancy density and surface active site coverage of the catalyst, thereby improving the yield of acrylamide.

[0113] The catalysts regenerated in Example 3 and Comparative Example 1 were run continuously for 200 hours, and samples were taken every 24 hours to test the acrylamide yield. The stability of the catalysts regenerated in Example 3 and Comparative Example 1 was compared, and the data obtained are shown in Table 2 below:

[0114] Table 2

[0115] Running time (h) Comparative Example 1 Yield (%) Example 3 Yield (%) 24 71.8±1.1 83.5±0.8 100 65.2±1.5 80.1±1.0 200 58.4±2.0 77.6±1.2

[0116] The catalyst in Example 3 maintained a yield of 77.6% after 200 hours, significantly improving stability compared to Comparative Example 1 (58.4%) and extending its lifespan by approximately 50%. The ionic liquid grafted layer on the modified silica gel effectively inhibited carbon deposition and metal sintering, maintaining the catalyst's pore structure and active sites.

[0117] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A process for the activation and regeneration of a deactivated copper catalyst, characterized in that: The following steps are involved: S1 washing and alkali treatment: the newly added copper catalyst was washed with deionized water 4-5 times, and then immersed in a 5-10% sodium hydroxide solution for 18-20h to obtain a pretreated catalyst; S2. Cleaning: Soak the pretreated catalyst in deionized water at 60-70 ° C for 18-20h to obtain a dealkalized catalyst; S3 mixed filling: The dealkalized catalyst and the deactivated copper catalyst are thoroughly mixed and sequentially loaded into the three-stage reactor for cyclic regeneration operation; S4. Functionalization of modified silica gel: adding the modified silica gel to the tertiary reactor after the cyclic regeneration operation for functionalization modification to obtain a modified catalyst; S5. Activation and Reduction: Liquid caustic soda is added to the modified catalyst in batches, and the generated hydrogen is reduced with copper oxide at 250-300°C. Activation treatment is then performed at 150-200°C to obtain a regenerated, highly efficient copper catalyst. The preparation of the modified silica gel comprises the following steps: S11 silica gel pretreatment: 10-15 parts of mesoporous silica gel was immersed in 50-70 parts of the modified sol and refluxed at 70-80 ° C for 5-6h to obtain a preliminary modified silica gel; S12. Ionic liquid grafting: The preliminarily modified silica gel was reacted with 20-40 parts of 1-butyl-3-methylimidazolium tetrafluoroborate in toluene for 10-12 hours, washed with ethanol 3-4 times, and dried under vacuum at 50-60°C to obtain modified silica gel.

2. The activation and regeneration preparation process for a deactivated copper catalyst according to claim 1, characterized in that: The mass ratio of the catalyst after screening in step S3 to the deactivated copper catalyst is 1:

2.

3. The activation and regeneration preparation process for a deactivated copper catalyst according to claim 1, characterized in that: The cyclic regeneration operation of step S3 uses sodium hydroxide with an end point concentration of 15% to cyclically regenerate the catalyst loaded in the three-stage reactor. In the initial stage, the sodium hydroxide concentration is 5%, and then the sodium hydroxide concentration is increased by 1% every two hours for a control time of 20 hours.

4. The activation and regeneration preparation process for a deactivated copper catalyst according to claim 1, characterized in that: The preparation of the modified sol comprises the following steps: S111 7-10 parts of 3-aminopropyltriethoxysilane and 2-5 parts of mercaptopropyltrimethoxysilane are dissolved in 90-100 parts of anhydrous ethanol, and 0.1-0.5 parts by mass concentration of 36-38% hydrochloric acid is added as a catalyst; S112. Add 0.5-1 parts of the composite nanoparticles to the solution obtained in step S111, stir at a constant temperature of 40-50°C for 4-6 hours to form a uniform sol, and then let it stand and mature for 10-12 hours to obtain a modified sol.

5. The activation and regeneration preparation process for a deactivated copper catalyst according to claim 4, characterized in that: The preparation of the composite nanoparticles comprises the following steps: S1121. Lanthanum nitrate and cerium nitrate were mixed and added to a 10-15% ammonia solution and reacted for 1-2h; S1122. The solution obtained in step S1121 is washed by centrifugation and dried, and calcined at 500-600° C. for 3-4 hours to obtain composite nanoparticles.

6. The activation and regeneration preparation process for a deactivated copper catalyst according to claim 1, characterized in that: The mass ratio of the modified silica gel to the mixed catalyst obtained in step S3 is 1:

5.

7. The activation and regeneration preparation process for a deactivated copper catalyst according to claim 1, characterized in that: The step S5 of adding the liquid caustic soda in batches specifically includes adding a sodium hydroxide solution with a mass concentration of 10-15% in 3-4 times, with an interval of 20-30 minutes between each addition.

8. The activation and regeneration preparation process for a deactivated copper catalyst according to claim 1, characterized in that: The time for the reduction reaction and activation treatment in step S5 is 2-3 h and 2-4 h, respectively.

9. The activation and regeneration preparation process for a deactivated copper catalyst according to claim 5, characterized in that: The mass ratio of lanthanum nitrate to cerium nitrate is 1:

3.

10. Use of a regenerated high-efficiency copper catalyst prepared according to the process for activating and regenerating a deactivated copper catalyst according to any one of claims 1 to 9 in the production of acrylamide.

Images