Regeneration method of phenol hydrogenation reaction catalyst
The phenol hydrogenation reaction catalyst is regenerated by a vacuum program heating drying method, which solves the problem in the prior art that the activity and structure of the catalyst cannot be restored simultaneously, and realizes the efficient regeneration and industrial application of the catalyst.
Patent Information
- Application Number
- CN202510692254.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-27
- Publication Date
- 2025-09-12
AI Technical Summary
Existing phenol hydrogenation catalyst regeneration methods cannot simultaneously achieve catalyst activity recovery and structural preservation under mild conditions, resulting in rapid catalyst deactivation and limiting the industrial application of phenol hydrogenation processes.
The phenol hydrogenation reaction catalyst is regenerated by a vacuum-assisted programmed temperature drying method. The specific steps include separating the catalyst from the reaction solution, subjecting the solution to vacuum-assisted programmed temperature drying, and controlling the heating rate and temperature range to restore the activity and structure of the catalyst.
The catalyst's activity recovery and structural preservation are achieved, making it suitable for large-scale industrial applications. It does not require the use of organic solvents, is safe and environmentally friendly, and meets green environmental protection requirements.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of catalyst regeneration, and in particular to a regeneration method for a phenol hydrogenation reaction catalyst. Background Art
[0002] Cyclohexanol and cyclohexanone are core raw materials in the nylon industry chain. Their traditional production process (cyclohexane oxidation) requires high temperature and high pressure, and the resulting byproducts pollute the environment, making it difficult to meet the needs of green chemical development. Phenol hydrogenation offers advantages such as simplicity and mild reaction conditions. The introduction of biomass / coal-based phenol feedstocks also enhances the process's sustainability, making it a research hotspot.
[0003] The catalysts commonly used in phenol hydrogenation are primarily supported catalysts, with supports such as activated carbon, molecular sieves, and alumina, and active ingredients such as platinum, palladium, and ruthenium. However, the industrialization of phenol hydrogenation is severely hampered by catalyst deactivation. Research has shown that organic molecules in the phenol hydrogenation reaction can form a confined adsorption effect within the porous catalyst, resulting in the covering of active sites and clogging of pores, leading to a rapid degradation of catalytic performance.
[0004] Currently, the regeneration methods for phenol hydrogenation catalysts mainly include high-temperature roasting, solvent washing, and redox methods. However, these methods all have significant drawbacks, specifically: although high-temperature roasting can remove organic matter on the catalyst surface, the intense heat treatment can also cause sintering of metal particles in the catalyst and collapse of the support structure; the solvent washing method requires the use of toxic and hazardous organic solvents, making solvent recovery difficult and posing a risk of secondary pollution; and the redox method has complex process control conditions, making it difficult to achieve large-scale application. In summary, the existing phenol hydrogenation catalyst regeneration methods are unable to simultaneously achieve catalyst activity recovery and catalyst structural preservation under mild conditions, greatly limiting their practical application.
[0005] Therefore, it is of great significance to develop a phenol hydrogenation catalyst regeneration method that is efficient, low-cost, safe and environmentally friendly and can simultaneously achieve catalyst activity recovery and catalyst structure preservation. Summary of the Invention
[0006] The object of the present invention is to provide a method for regenerating a phenol hydrogenation catalyst.
[0007] The technical solution adopted by the present invention is:
[0008] A regeneration method for a phenol hydrogenation reaction catalyst comprises the following steps: separating the phenol hydrogenation reaction catalyst from a reaction liquid, and then subjecting the reaction liquid to programmed temperature drying under vacuum conditions.
[0009] Preferably, the phenol hydrogenation reaction catalyst is a supported catalyst.
[0010] Preferably, the carrier in the supported catalyst is one of nitrogen-doped porous carbon, activated carbon, molecular sieve, and alumina.
[0011] Further preferably, the carrier in the supported catalyst is nitrogen-doped porous carbon.
[0012] Preferably, the active component in the supported catalyst is at least one of platinum, palladium, ruthenium, rhodium, cobalt and nickel.
[0013] More preferably, the active component in the supported catalyst is at least one of platinum, palladium and ruthenium.
[0014] Preferably, the phenol hydrogenation reaction catalyst is separated from the reaction solution by filtration, suction filtration, or centrifugation.
[0015] Preferably, the absolute pressure of the vacuum condition is 0.1 bar to 0.5 bar.
[0016] Preferably, the programmed temperature drying includes the following process: first controlling the heating rate to be 1°C / min to 3°C / min to heat from room temperature to 130°C to 150°C, keeping warm for 1h to 2h, then controlling the heating rate to be 1°C / min to 3°C / min to continue heating to 160°C to 170°C, keeping warm for 1h to 3h.
[0017] Preferably, the products of the phenol hydrogenation reaction are cyclohexanol and cyclohexanone.
[0018] The beneficial effects of the present invention are as follows: the regeneration method of the phenol hydrogenation reaction catalyst of the present invention can simultaneously achieve catalyst activity recovery and catalyst structure preservation, and the regeneration method is efficient, low-cost, safe and environmentally friendly, and is suitable for large-scale industrial application.
[0019] Specifically:
[0020] 1) The regeneration method of the phenol hydrogenation reaction catalyst of the present invention can simultaneously achieve catalyst activity recovery and catalyst structure preservation without damaging the catalyst structure;
[0021] 2) The regeneration method of the phenol hydrogenation reaction catalyst of the present invention does not require the use of any organic solvent, is safe and environmentally friendly, and meets green environmental protection requirements;
[0022] 3) The regeneration method of the phenol hydrogenation reaction catalyst of the present invention is simple to operate, the equipment is simple and readily available, and is suitable for large-scale industrial application. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1These are the nitrogen adsorption-desorption isotherms of Pt / NPC-F, Pt / NPC-U5, and Pt / NPC-R5 in Example 1.
[0024] Figure 2 This is the pore size distribution diagram of Pt / NPC-F, Pt / NPC-U5 and Pt / NPC-R5 in Example 1. DETAILED DESCRIPTION
[0025] The present invention will be further explained and illustrated below with reference to specific embodiments.
[0026] Example 1:
[0027] A supported platinum catalyst, the preparation method of which is as follows:
[0028] 1) Glucose, melamine, and ammonium chloride were mixed and ball-milled in a mass ratio of 1:5:5, and then calcined at 900°C for 2 h in an argon atmosphere. The calcined product was then dispersed in a 30% nitric acid solution in a ratio of 1 g:1000 mL. The mixture was stirred at 60°C for 2 h, filtered, and the solid was washed thoroughly with deionized water until the washing solution was neutral. The solid was then dried in a forced air drying oven at 80°C for 12 h to obtain nitrogen-doped porous carbon (NPC).
[0029] 2) Nitrogen-doped porous carbon and platinum chloride hydrochloric acid solution (prepared by platinum chloride and 5% hydrochloric acid solution by volume in a ratio of 1 g:150 mL) were ultrasonically dispersed in deionized water, and the amount ratio of nitrogen-doped porous carbon, platinum chloride hydrochloric acid solution, and deionized water was 1 g:20 mL:5000 mL. The mixture was then placed in a water bath at 80°C and stirred for 2 h. Potassium hydroxide solution was then slowly added to adjust the pH value of the system to 9.0. The mixture was filtered, and the solid was placed in a hydrogen atmosphere and reduced at 300°C for 2 h to obtain a supported platinum catalyst (denoted as Pt / NPC-F; F represents a fresh catalyst).
[0030] A method for preparing cyclohexanone and cyclohexanol by hydrogenating phenol, comprising the following steps:
[0031] 117.64 mg of phenol, 37.50 mg of supported platinum catalyst (Pt / NPC-F) and 10 mL of deionized water were added to a high-temperature and high-pressure reactor. The reactor was closed, the atmosphere in the reactor was replaced with hydrogen three times, and then heated to 80°C. The hydrogen pressure in the reactor was adjusted to 0.1 MPa, the stirring rate was adjusted to 1500 r / min, the reaction was carried out for 1 hour, and the reaction was filtered to obtain a supported platinum catalyst used once (denoted as Pt / NPC-U1; U1 indicates a catalyst used once) and a reaction solution (containing cyclohexanone and cyclohexanol), respectively.
[0032] Gas chromatography analysis of the reaction liquid:
[0033] The reaction solution was extracted three times with ethyl acetate, using 10 mL of ethyl acetate for each extraction. The organic phases were combined and 11 μL of toluene was added. The mixture was allowed to stand for 5 min and analyzed by gas chromatography. The phenol conversion, cyclohexanone selectivity, and cyclohexanol selectivity were calculated based on the standard curve.
[0034] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0035] The supported platinum catalyst (Pt / NPC-U1) used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and the absolute pressure in the drying oven was maintained at 0.1 bar, and then the temperature was raised from room temperature to 150°C at a heating rate of 2°C / min, kept warm for 2 hours, and then the temperature was continued to be raised to 170°C at a heating rate of 2°C / min, kept warm for 1 hour, to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1; R1 represents the catalyst recovered for the first time).
[0036] Performance testing:
[0037] Phenol hydrogenation to cyclohexanone and cyclohexanol and regeneration of the supported platinum catalyst were carried out in a cycle according to the method in this embodiment. A total of 5 cycles were performed, and then nitrogen adsorption-desorption experiments were performed on the fresh supported platinum catalyst (Pt / NPC-F), the supported platinum catalyst used 5 times (Pt / NPC-U5), and the supported platinum catalyst recovered 5 times (Pt / NPC-R5). The obtained nitrogen adsorption-desorption isotherms and pore size distribution diagrams are shown in the following order. Figure 1 and Figure 2 The specific surface area and pore volume test results of the supported platinum catalyst are shown in Table 1, and the test results of phenol conversion, cyclohexanone selectivity and cyclohexanol selectivity are shown in Table 2:
[0038] Table 1 Specific surface area and pore volume test results of supported platinum catalyst
[0039]
[0040]
[0041] Table 2 Test results of phenol conversion, cyclohexanone selectivity and cyclohexanol selectivity
[0042] Number of cycles Phenol conversion rate (%) Cyclohexanone selectivity (%) Cyclohexanol selectivity (%) 1 95.4 16.6 83.4 2 95.0 16.5 83.5 3 95.2 16.5 83.5 4 94.8 16.8 83.2 5 95.5 17.1 82.9
[0043] Depend on Figure 1 、 Figure 2 As shown in Table 1, after the supported platinum catalyst (Pt / NPC-F) was regenerated, the specific surface area increased from 63.13 m 2 / g recovered to 153.38m2 / g, pore volume from 0.32cm 3 / g recovered to 0.47cm 3 / g, the specific surface area and pore volume can be restored to more than 85% of the initial value, indicating that the regeneration method of the phenol hydrogenation reaction catalyst of the present invention can indeed achieve the structural preservation of the catalyst.
[0044] As shown in Table 2, the conversion rate of phenol remained essentially unchanged after five cycles of the supported platinum catalyst (Pt / NPC-F), indicating that the regeneration method of the phenol hydrogenation catalyst of the present invention can indeed achieve both catalyst activity recovery and catalyst structure preservation.
[0045] Example 2:
[0046] A supported palladium catalyst, the preparation method of which is as follows:
[0047] Nitrogen-doped porous carbon (same as in Example 1) and a palladium chloride hydrochloric acid solution (prepared by palladium chloride and a 5% volume fraction hydrochloric acid solution in a ratio of 1 g: 80 mL) were ultrasonically dispersed in deionized water. The amount ratio of nitrogen-doped porous carbon, palladium chloride hydrochloric acid solution, and deionized water was 1 g: 5 mL: 5000 mL. The mixture was then placed in a water bath at 80 ° C and stirred for 2 h. Potassium hydroxide solution was then slowly added to adjust the pH value of the system to 9.0. The mixture was filtered, and the solid was placed in a hydrogen atmosphere at 300 ° C and reduced for 2 h to obtain a supported palladium catalyst (denoted as Pd / NPC-F).
[0048] A method for preparing cyclohexanone and cyclohexanol by hydrogenating phenol is identical to Example 1 except that the weight of the "supported platinum catalyst" is replaced by a "supported palladium catalyst".
[0049] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0050] The supported palladium catalyst (Pd / NPC-U1) used once was filtered and separated from the reaction solution, and then placed in a drying oven, evacuated and the absolute pressure in the drying oven was maintained at 0.1 bar. The temperature was then raised from room temperature to 150°C at a heating rate of 2°C / min and kept warm for 2 hours. The temperature was then raised to 170°C at a heating rate of 2°C / min and kept warm for 1 hour to obtain the first recovered supported palladium catalyst (denoted as Pd / NPC-R1).
[0051] Performance testing:
[0052] Phenol hydrogenation to cyclohexanone and cyclohexanol and regeneration of the supported palladium catalyst were carried out cyclically according to the method in this embodiment. A total of 5 cycles were performed. The test results of phenol conversion, cyclohexanone selectivity, and cyclohexanol selectivity obtained are shown in the following table:
[0053] Table 3 Test results of phenol conversion, cyclohexanone selectivity and cyclohexanol selectivity
[0054] Number of cycles Phenol conversion rate (%) Cyclohexanone selectivity (%) Cyclohexanol selectivity (%) 1 90.8 97.7 2.3 2 91.0 98.1 1.9 3 90.5 98.0 2.0 4 90.1 98.1 1.9 5 89.9 98.2 1.8
[0055] As shown in Table 3, the conversion rate of phenol remained substantially unchanged after five cycles of the supported palladium catalyst (Pd / NPC-F), indicating that the regeneration method of the phenol hydrogenation catalyst of the present invention can indeed achieve both catalyst activity recovery and catalyst structure preservation.
[0056] Example 3:
[0057] A supported ruthenium catalyst, the preparation method of which is as follows:
[0058] Nitrogen-doped porous carbon (same as in Example 1) and a ruthenium chloride hydrochloric acid solution (prepared by ruthenium chloride and a 5% volume fraction hydrochloric acid solution in a dosage ratio of 1 g: 250 mL) were ultrasonically dispersed in deionized water. The dosage ratio of nitrogen-doped porous carbon, ruthenium chloride hydrochloric acid solution, and deionized water was 1 g: 20 mL: 5000 mL. The mixture was then placed in a water bath at 80°C and stirred for 2 h. Potassium hydroxide solution was then slowly added to adjust the pH value of the system to 9.0. The mixture was filtered, and the solid was placed in a hydrogen atmosphere and reduced at 300°C for 2 h to obtain a supported ruthenium catalyst (denoted as Ru / NPC-F).
[0059] A method for preparing cyclohexanone and cyclohexanol by hydrogenating phenol is identical to Example 1 except that the weight of the "supported platinum catalyst" is replaced by a "supported ruthenium catalyst".
[0060] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0061] The loaded ruthenium catalyst (Ru / NPC-U1) used once was separated from the reaction solution by filtration, and then placed in a drying oven, evacuated and the absolute pressure in the drying oven was maintained at 0.1 bar. The temperature was then raised from room temperature to 150°C at a heating rate of 2°C / min, and kept warm for 2 hours. The temperature was then raised to 170°C at a heating rate of 2°C / min, and kept warm for 1 hour to obtain the first recovered loaded ruthenium catalyst (denoted as Ru / NPC-R1).
[0062] Performance testing:
[0063] Phenol hydrogenation to cyclohexanone and cyclohexanol and regeneration of the supported ruthenium catalyst were performed cyclically according to the method in this example. A total of 5 cycles were performed. The test results of phenol conversion, cyclohexanone selectivity, and cyclohexanol selectivity are shown in the following table:
[0064] Table 4 Test results of phenol conversion, cyclohexanone selectivity and cyclohexanol selectivity
[0065] Number of cycles Phenol conversion rate (%) Cyclohexanone selectivity (%) Cyclohexanol selectivity (%) 1 98.2 0.3 99.7 2 97.9 0.5 99.5 3 98.5 0.1 99.9 4 98.2 0.2 99.8 5 97.8 0.5 99.5
[0066] As shown in Table 4, the conversion rate of phenol remained essentially unchanged after five cycles of the supported ruthenium catalyst (Ru / NPC-F), indicating that the regeneration method of the phenol hydrogenation catalyst of the present invention can indeed achieve both catalyst activity recovery and catalyst structure preservation.
[0067] Example 4:
[0068] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0069] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) that had been used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 130°C at a heating rate of 2°C / min and kept at that temperature for 2 h. The temperature was then raised to 170°C at a heating rate of 2°C / min and kept at that temperature for 1 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0070] Performance testing:
[0071] Phenol was hydrogenated to produce cyclohexanone and cyclohexanol cyclically according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this example. A total of five cycles were performed. Testing showed that after five cycles of the supported platinum catalyst (Pt / NPC-F), the conversion of phenol decreased from 95.4% to 86.9%, with a very small decrease. This indicates that the regeneration method of the phenol hydrogenation catalyst of the present invention can indeed achieve both catalyst activity recovery and catalyst structural preservation.
[0072] Example 5:
[0073] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0074] The supported palladium catalyst (Pd / NPC-U1) used once was filtered and separated from the reaction solution, and then placed in a drying oven, evacuated and the absolute pressure in the drying oven was maintained at 0.1 bar. The temperature was then raised from room temperature to 140°C at a heating rate of 2°C / min and kept warm for 2 hours. The temperature was then raised to 160°C at a heating rate of 2°C / min and kept warm for 3 hours to obtain the first recovered supported palladium catalyst (denoted as Pd / NPC-R1).
[0075] Performance testing:
[0076] Phenol hydrogenation to cyclohexanone and cyclohexanol was carried out cyclically with reference to the method in Example 2, and the supported palladium catalyst was regenerated cyclically with reference to the method in this example. A total of 5 cycles were performed. Testing showed that after 5 cycles of the supported palladium catalyst (Pd / NPC-F), the conversion rate of phenol decreased from 90.8% to 83.7%, with a very small decrease. This indicates that the regeneration method of the phenol hydrogenation catalyst of the present invention can indeed achieve both catalyst activity recovery and catalyst structural preservation.
[0077] Example 6:
[0078] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0079] The loaded ruthenium catalyst (Ru / NPC-U1) used once was separated from the reaction solution by filtration, and then placed in a drying oven, evacuated and the absolute pressure in the drying oven was maintained at 0.1 bar. The temperature was then raised from room temperature to 150°C at a heating rate of 2°C / min, and kept warm for 2 hours. The temperature was then raised to 170°C at a heating rate of 2°C / min, and kept warm for 3 hours to obtain the first recovered loaded ruthenium catalyst (denoted as Ru / NPC-R1).
[0080] Performance testing:
[0081] Phenol was hydrogenated to produce cyclohexanone and cyclohexanol cyclically according to the method in Example 3, and the supported ruthenium catalyst was regenerated cyclically according to the method in this example. A total of 5 cycles were performed. Testing showed that after 5 cycles of the supported ruthenium catalyst (Ru / NPC-F), the conversion rate of phenol decreased from 98.2% to 93.5%, and the decrease was very small. This shows that the regeneration method of the phenol hydrogenation reaction catalyst of the present invention can indeed achieve both catalyst activity recovery and catalyst structure preservation.
[0082] Comparative Example 1:
[0083] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0084] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated while maintaining the absolute pressure in the drying oven at 0.1 bar, and then dried at 60°C for 12 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0085] Performance testing:
[0086] Phenol was hydrogenated to produce cyclohexanone and cyclohexanol in a cycle according to the method in Example 1, and the supported platinum catalyst was regenerated in a cycle according to the method in this comparative example. A total of three cycles were performed. The test results of phenol conversion, cyclohexanone selectivity, and cyclohexanol selectivity are shown in Table 5:
[0087] Table 5 Test results of phenol conversion, cyclohexanone selectivity and cyclohexanol selectivity
[0088] Number of cycles Phenol conversion rate (%) Cyclohexanone selectivity (%) Cyclohexanol selectivity (%) 1 95.4 16.6 83.4 2 84.3 24.5 75.5 3 69.8 34.4 65.6
[0089] As shown in Table 5, after three cycles, the phenol conversion rate of the supported platinum catalyst (Pt / NPC-F) decreased significantly from 95.4% to 69.8%, indicating obvious deactivation. This indicates that the regeneration method for the phenol hydrogenation catalyst in this comparative example is not able to effectively restore the catalyst activity and preserve the catalyst structure.
[0090] Comparative Example 2:
[0091] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0092] The supported palladium catalyst (Pd / NPC-U1; same as in Example 2) used once was separated by filtration from the reaction solution, then placed in a drying oven, evacuated while maintaining the absolute pressure in the drying oven at 0.1 bar, and then dried at 60°C for 12 h to obtain the first recovered supported palladium catalyst (denoted as Pd / NPC-R1).
[0093] Performance testing:
[0094] Phenol was hydrogenated to produce cyclohexanone and cyclohexanol in a cycle according to the method in Example 2, and the supported palladium catalyst was regenerated in a cycle according to the method in this comparative example. A total of three cycles were performed. The test results of phenol conversion, cyclohexanone selectivity, and cyclohexanol selectivity are shown in Table 6:
[0095] Table 6 Test results of phenol conversion, cyclohexanone selectivity and cyclohexanol selectivity
[0096] Number of cycles Phenol conversion rate (%) Cyclohexanone selectivity (%) Cyclohexanol selectivity (%) 1 90.8 97.7 2.3 2 81.9 98.4 1.6 3 74.6 98.5 1.5
[0097] As shown in Table 6, after three cycles, the phenol conversion rate of the supported palladium catalyst (Pd / NPC-F) decreased significantly from 90.8% to 74.6%, indicating a significant deactivation phenomenon. This indicates that the regeneration method of the phenol hydrogenation catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0098] Comparative Example 3:
[0099] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0100] The loaded ruthenium catalyst (Ru / NPC-U1; same as in Example 3) used once was separated from the reaction solution by filtration, then placed in a drying oven, evacuated and the absolute pressure in the drying oven was maintained at 0.1 bar, and then dried at 60°C for 12 hours to obtain the first recovered loaded ruthenium catalyst (denoted as Ru / NPC-R1).
[0101] Performance testing:
[0102] Phenol was hydrogenated to produce cyclohexanone and cyclohexanol cyclically according to the method in Example 3, and the supported ruthenium catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed. The test results of phenol conversion, cyclohexanone selectivity, and cyclohexanol selectivity are shown in Table 7:
[0103] Table 7 Test results of phenol conversion, cyclohexanone selectivity and cyclohexanol selectivity
[0104] Number of cycles Phenol conversion rate (%) Cyclohexanone selectivity (%) Cyclohexanol selectivity (%) 1 98.2 0.3 99.7 2 87.8 2.8 97.2 3 80.6 3.0 97.0
[0105] As shown in Table 7, after three cycles, the phenol conversion rate of the supported ruthenium catalyst (Ru / NPC-F) decreased significantly from 98.2% to 80.6%, indicating a significant deactivation phenomenon. This indicates that the regeneration method of the phenol hydrogenation catalyst in this comparative example is not able to effectively restore the catalyst activity and preserve the catalyst structure.
[0106] Comparative Example 4:
[0107] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0108] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 90°C at a heating rate of 2°C / min and kept at that temperature for 2 h. The temperature was then raised to 160°C at a heating rate of 2°C / min and kept at that temperature for 1 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0109] Performance testing:
[0110] Phenol hydrogenation to cyclohexanone and cyclohexanol was cyclically carried out according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed, and the phenol conversion rate decreased from 95.4% to 77.2%, a large decrease, indicating a relatively obvious deactivation phenomenon. This indicates that the regeneration method of the phenol hydrogenation reaction catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0111] Comparative Example 5:
[0112] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0113] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) that had been used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 120°C at a heating rate of 2°C / min and kept at that temperature for 2 h. The temperature was then raised to 160°C at a heating rate of 2°C / min and kept at that temperature for 1 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0114] Performance testing:
[0115] Phenol hydrogenation to cyclohexanone and cyclohexanol was carried out cyclically according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed, and the phenol conversion rate decreased from 95.4% to 82.6%, a large decrease, indicating a relatively obvious deactivation phenomenon. This indicates that the regeneration method of the phenol hydrogenation reaction catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0116] Comparative Example 6:
[0117] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0118] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 130°C at a heating rate of 2°C / min and kept at that temperature for 2 h. The temperature was then raised to 150°C at a heating rate of 3°C / min and kept at that temperature for 1 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0119] Performance testing:
[0120] Phenol hydrogenation to cyclohexanone and cyclohexanol was cyclically carried out according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed, and the phenol conversion rate decreased significantly from 95.4% to 79.8%, indicating obvious deactivation. This indicates that the regeneration method of the phenol hydrogenation catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0121] Comparative Example 7:
[0122] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0123] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) that had been used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 130°C at a heating rate of 2°C / min and kept at that temperature for 2 h. The temperature was then raised to 180°C at a heating rate of 3°C / min and kept at that temperature for 1 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0124] Performance testing:
[0125] Phenol hydrogenation to cyclohexanone and cyclohexanol was cyclically carried out according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed, and the phenol conversion rate decreased significantly from 95.4% to 65.4%, indicating obvious deactivation. This indicates that the regeneration method of the phenol hydrogenation catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0126] Comparative Example 8:
[0127] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0128] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) that had been used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 150°C at a heating rate of 2°C / min and kept at that temperature for 2 h. The temperature was then raised to 200°C at a heating rate of 3°C / min and kept at that temperature for 1 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0129] Performance testing:
[0130] Phenol hydrogenation to cyclohexanone and cyclohexanol was cyclically carried out according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed, and the phenol conversion rate decreased from 95.4% to 50.5%, a significant decrease, indicating obvious deactivation. This indicates that the regeneration method of the phenol hydrogenation reaction catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0131] Comparative Example 9:
[0132] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0133] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) that had been used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 150°C at a heating rate of 2°C / min and kept at that temperature for 2 h. The temperature was then raised to 250°C at a heating rate of 3°C / min and kept at that temperature for 1 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0134] Performance testing:
[0135] Phenol hydrogenation to cyclohexanone and cyclohexanol was cyclically carried out according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed. The phenol conversion rate decreased significantly from 95.4% to 30.1%, indicating obvious deactivation. This indicates that the regeneration method of the phenol hydrogenation catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0136] Comparative Example 10:
[0137] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0138] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) that had been used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 130°C at a heating rate of 2°C / min and kept at that temperature for 2 h. The temperature was then raised to 170°C at a heating rate of 5°C / min and kept at that temperature for 1 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0139] Performance testing:
[0140] Phenol hydrogenation to cyclohexanone and cyclohexanol was carried out cyclically according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed, and the phenol conversion rate decreased from 95.4% to 84.6%, a large decrease, indicating a relatively obvious deactivation phenomenon. This indicates that the regeneration method of the phenol hydrogenation reaction catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0141] Comparative Example 11:
[0142] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0143] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) that had been used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 130°C at a heating rate of 2°C / min and kept at that temperature for 2 h. The temperature was then raised to 170°C at a heating rate of 10°C / min and kept at that temperature for 1 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0144] Performance testing:
[0145] Phenol hydrogenation to cyclohexanone and cyclohexanol was cyclically carried out according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed, and the phenol conversion rate decreased from 95.4% to 71.8%, a significant decrease, indicating obvious deactivation. This indicates that the regeneration method of the phenol hydrogenation reaction catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0146] Comparative Example 12:
[0147] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0148] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) that had been used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 130°C at a heating rate of 5°C / min and kept at that temperature for 2 h. The temperature was then raised to 170°C at a heating rate of 3°C / min and kept at that temperature for 5 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0149] Performance testing:
[0150] Phenol hydrogenation to cyclohexanone and cyclohexanol was carried out cyclically according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed, and the phenol conversion rate decreased from 95.4% to 83.9%, a significant decrease, indicating a relatively obvious deactivation phenomenon. This indicates that the regeneration method of the phenol hydrogenation reaction catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0151] Comparative Example 13:
[0152] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0153] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) that had been used once was filtered and separated from the reaction solution, then placed in a drying oven, evacuated and maintained at an absolute pressure of 0.1 bar. The temperature was then raised from room temperature to 130°C at a heating rate of 2°C / min and kept at that temperature for 2 h. The temperature was then raised to 170°C at a heating rate of 3°C / min and kept at that temperature for 7 h to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0154] Performance testing:
[0155] Phenol hydrogenation to cyclohexanone and cyclohexanol was cyclically performed according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed, and the phenol conversion rate decreased from 95.4% to 76.6%, a significant decrease, indicating a relatively obvious deactivation phenomenon. This indicates that the regeneration method of the phenol hydrogenation reaction catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0156] Comparative Example 14:
[0157] A method for regenerating a phenol hydrogenation catalyst comprises the following steps:
[0158] The supported platinum catalyst (Pt / NPC-U1; same as in Example 1) used once was separated from the reaction solution by filtration, and then annealed at 300°C for 3 h in an argon atmosphere to obtain the first recovered supported platinum catalyst (denoted as Pt / NPC-R1).
[0159] Performance testing:
[0160] Phenol hydrogenation to cyclohexanone and cyclohexanol was cyclically carried out according to the method in Example 1, and the supported platinum catalyst was regenerated cyclically according to the method in this comparative example. A total of three cycles were performed. The phenol conversion rate decreased significantly from 95.4% to 30.6%, indicating obvious deactivation. This indicates that the regeneration method of the phenol hydrogenation catalyst in this comparative example cannot effectively restore the catalyst activity and preserve the catalyst structure.
[0161] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.
Claims
1. A method for regenerating a phenol hydrogenation catalyst, characterized in that: The following steps are involved: The phenol hydrogenation reaction catalyst is separated from the reaction liquid, and then placed under vacuum conditions for programmed temperature drying.
2. The regeneration method of phenol hydrogenation catalyst according to claim 1, wherein: The phenol hydrogenation reaction catalyst is a supported catalyst.
3. The regeneration method of phenol hydrogenation catalyst according to claim 2, wherein: The carrier in the supported catalyst is one of nitrogen-doped porous carbon, activated carbon, molecular sieve and alumina.
4. The regeneration method of phenol hydrogenation catalyst according to claim 3, wherein: The carrier in the supported catalyst is nitrogen-doped porous carbon.
5. The regeneration method of phenol hydrogenation catalyst according to claim 2, wherein: The active component in the supported catalyst is at least one of platinum, palladium, ruthenium, rhodium, cobalt and nickel.
6. The regeneration method of phenol hydrogenation catalyst according to claim 5, wherein: The active component in the supported catalyst is at least one of platinum, palladium and ruthenium.
7. The method for regenerating a phenol hydrogenation catalyst according to any one of claims 1 to 6, wherein: The phenol hydrogenation reaction catalyst is separated from the reaction solution by filtering, suction filtration, or centrifugation.
8. The method for regenerating a phenol hydrogenation catalyst according to any one of claims 1 to 6, wherein: The absolute pressure of the vacuum condition is 0.1 bar to 0.5 bar.
9. The method for regenerating a phenol hydrogenation catalyst according to any one of claims 1 to 6, wherein: The programmed temperature drying includes the following process: first controlling the heating rate to be 1°C / min to 3°C / min to heat from room temperature to 130°C to 150°C, keeping the temperature for 1h to 2h, then controlling the heating rate to be 1°C / min to 3°C / min to continue heating to 160°C to 170°C, and keeping the temperature for 1h to 3h.
10. The method for regenerating a phenol hydrogenation catalyst according to any one of claims 1 to 6, wherein: The products of the phenol hydrogenation reaction are cyclohexanol and cyclohexanone.