A nickel-based catalytic material for the full hydrogenation of N-ethylcarbazole and a method for preparing the same

Abstract

The application discloses a kind of nickel-based catalytic materials for N-ethylcarbazole total hydrogenation and preparation method thereof, belong to catalytic material technical field.The application is modified by using silicon oxide, cerium oxide in the process of drop ball forming, and then the impregnation solution is prepared by organic complexing agent, and the equal volume impregnation method is used to load nickel and one or more kinds of additives such as molybdenum oxide, cobalt oxide, zinc oxide and copper oxide on the matrix, to obtain the nickel-based catalytic material for N-ethylcarbazole total hydrogenation.The application can realize the precise control of the pore size and pore distribution of the catalytic material, significantly improve the utilization rate of active components in the catalytic material, and strengthen the mass transfer efficiency in the N-ethylcarbazole hydrogenation reaction process.The catalytic material applied to N-ethylcarbazole total hydrogenation reaction shows excellent N-ethylcarbazole conversion rate, hydrogenation amount and hydrogenation rate, and has stable performance after regeneration, and can be recycled for catalytic hydrogen storage process.

Description

Technical Field

[0001] This invention belongs to the field of catalytic materials technology, specifically relating to a nickel-based catalytic material for the full hydrogenation of N-ethylcarbazole and its preparation method. Background Technology

[0002] Hydrogen energy, as a clean and efficient secondary energy source, is a core carrier for achieving the "dual carbon" goal and energy structure transformation. The safe, efficient, and low-cost storage and transportation of hydrogen are key bottlenecks for the large-scale application of hydrogen energy. Liquid organic hydrogen storage technology, with its advantages of being a liquid at room temperature and pressure, having high hydrogen storage density, being able to reuse existing fuel storage and transportation facilities, and having strong safety, has become one of the most promising hydrogen storage technologies for industrialization. N-ethylcarbazole is one of the most widely studied and most promising liquid organic hydrogen storage carriers, with a theoretical hydrogen storage density of 5.8 wt%, possessing both high hydrogen storage capacity and excellent reversible hydrogen absorption and desorption performance. The core of N-ethylcarbazole hydrogen storage is the catalytic hydrogenation reaction, the efficiency of which directly determines the hydrogen storage rate, hydrogen storage capacity, and system economy. While existing precious metal hydrogenation catalytic systems have high hydrogenation activity and good selectivity, they are expensive. Nickel, as an inexpensive transition metal, is the preferred active component to replace precious metals. However, existing nickel-based hydrogenation catalysts suffer from problems such as easy agglomeration of active metal particles, poor dispersion, poor cycle stability, simple catalyst pore structure, low mass transfer efficiency, and slow hydrogenation reaction kinetics. They cannot simultaneously achieve high dispersion of active components, high mass transfer efficiency, and structural stability, resulting in hydrogenation performance that is lower than that of precious metal catalysts. They cannot meet the requirements of industrial hydrogen storage for high conversion rate, high hydrogen storage capacity, and high hydrogenation rate.

[0003] Chinese invention patent CN121571148A discloses a nickel catalyst for reversible hydrogen storage of N-ethylcarbazole. The catalyst prepared by co-precipitation reaction has an average particle size of 300-900 µm and a nickel content of 26-78% by mass. When the nickel content is 54 wt%, the N-ethylcarbazole conversion rate is 100% and the total hydrogen N-ethylcarbazole yield is 100% when hydrogenation reaction is carried out in a continuous flow fixed bed.

[0004] Chinese invention patent CN119215929A discloses a method for preparing a nickel-based catalyst loaded with a noble metal component. The method involves simultaneously adding a nickel metal salt solution and a precipitate to a support suspension for precipitation, obtaining a catalyst precursor suspension. This precursor is then aged and filtered to obtain the catalyst precursor itself. The catalyst precursor is washed, dried, and calcined to obtain a nickel-based catalyst. The obtained nickel-based catalyst is ground into powder, thoroughly mixed in deionized water, and a small amount of the noble metal precursor solution is added dropwise. The mixture is then stirred and evaporated to dryness to obtain the noble metal-loaded catalyst. This nickel-based catalyst can be used for the hydrogenation reaction of hydrogen-storing organic liquids such as N-ethylcarbazole, dibenzyltoluene, benzyltoluene, toluene, decahydronaphthalene, and biphenyl, exhibiting excellent hydrogenation performance. Summary of the Invention

[0005] The purpose of this invention is to provide a nickel-based catalytic material for the complete hydrogenation of N-ethylcarbazole and its preparation method, so as to improve the conversion rate, hydrogenation rate and stability of the nickel-based catalytic material for the catalytic hydrogenation of N-ethylcarbazole.

[0006] To achieve the above objectives, the present invention provides a nickel-based catalytic material for the full hydrogenation of N-ethylcarbazole, characterized in that the catalytic material comprises an alumina matrix, a main active component nickel, silicon oxide, cerium oxide, and an auxiliary component supported on the alumina matrix. Based on the total mass of the catalytic material (100%), the loading of the main active component nickel is 10.0-25.0 wt%, the loading of the silicon oxide is 0.05-1.00 wt%, the loading of the cerium oxide is 0.05-2.00 wt%, the auxiliary component is one or more of molybdenum oxide, cobalt oxide, zinc oxide, and copper oxide, and the loading of the auxiliary component is 0.05-10.00 wt%, with the remainder being the alumina matrix, wherein the alumina matrix is ​​a composite matrix of n-type and θ-type alumina.

[0007] The nickel-based catalytic material for the complete hydrogenation of N-ethylcarbazole according to the present invention is characterized in that the catalytic material has a stepped pore distribution, with an average pore size of 20.0-30.0 nm, the pore volume of pores with a diameter of 20.0-35.0 nm accounting for 35-45% of the total pore volume, the pore volume of pores with a diameter of 35.0-45.0 nm accounting for 20-45% of the total pore volume, and a pore volume of 0.50-1.20 cm³. 3 / g, specific surface area is 70-150 m² 2 / g.

[0008] To achieve the above objectives, the present invention also provides a method for preparing the nickel-based catalytic material for the complete hydrogenation of N-ethylcarbazole, characterized by comprising the following steps:

[0009] Aluminum source is added to acid solution to obtain aluminum sol. Aluminum sol is mixed with silica sol and cerium nitrate, and then template agent is added to obtain slurry. After drop ball molding, it is dried and calcined to obtain a silica- and cerium-modified alumina composite matrix.

[0010] Dissolve the soluble salt containing the active component nickel and the precursor of the auxiliary component in water, stir evenly, and then add organic acid and / or alcohol complexing agent to form a complex impregnation solution.

[0011] The alumina matrix was impregnated in a complex impregnation solution using an equal-volume impregnation method to obtain a catalytic material precursor;

[0012] The catalyst precursor was subjected to drying, calcination, and hydrogen reduction treatment in sequence to obtain a nickel-based catalyst for the full hydrogenation of N-ethylcarbazole.

[0013] The method for preparing the nickel-based catalyst material for the full hydrogenation of N-ethylcarbazole according to the present invention is characterized in that the drying and calcination process after droplet forming is sequentially performed by drying at 90-130 °C for 2-10 h and calcining at 900-1200 °C for 2-6 h; the drying, calcination, and hydrogen reduction treatment process of the catalyst material precursor is sequentially performed by drying at 80-130 °C for 1-5 h, calcining at 150-220 °C for 1-3 h, calcining at 300-400 °C for 1-3 h, and reducing at 400-550 °C for 2-5 h under a hydrogen atmosphere.

[0014] The method for preparing a nickel-based catalyst for the full hydrogenation of N-ethylcarbazole according to the present invention is characterized in that the aluminum source is one or more of boehmite, aluminum isopropoxide, aluminum chloride, and aluminum oxide; the mass ratio of the added acid solution to the aluminum source is (3-10):1, the mass fraction of the acid solution is 5-20 wt%, and the acid solution is one or more of hydrochloric acid, nitric acid, and sulfuric acid aqueous solution; the amount of the added template agent is 0.1-10.0% of the mass of the aluminum source, and the template agent is one or more of hexamethylenetetramine, polyvinyl alcohol, and polyethylene glycol.

[0015] The method for preparing the nickel-based catalytic material for the complete hydrogenation of N-ethylcarbazole according to the present invention is characterized in that the precursor of the auxiliary component includes one or more of ammonium molybdate, a soluble salt of cobalt, a soluble salt of zinc, and a soluble salt of copper.

[0016] The method for preparing nickel-based catalytic material for the complete hydrogenation of N-ethylcarbazole according to the present invention is characterized in that the amount of organic acid and / or alcohol complexing agent added is 0.5-20.0% of the mass of the main active component nickel, the organic acid complexing agent is one or more of tartaric acid, ethylenediaminetetraacetic acid, and citric acid, and the organic alcohol complexing agent is triethylene glycol.

[0017] The beneficial effects of this invention are as follows: By modifying alumina with silicon dioxide and cerium oxide, combined with a high-temperature calcination process, an alumina matrix with a stepped pore distribution is obtained, with pore sizes concentrated in the ranges of 20-35 nm and 35-45 nm, respectively. Smaller pore sizes effectively improve the dispersion of the active component, while larger pore sizes significantly enhance the mass transfer performance during the reaction. Simultaneously, the use of organic acids and / or alcohol complexing agents to prepare an impregnation solution containing the active and auxiliary components promotes the synergistic effect of the active and auxiliary components, significantly improving the utilization rate of the active component in the catalytic material. This invention uses non-precious metal nickel as the active component. When the prepared catalytic material is applied to the full hydrogenation reaction of N-ethylcarbazole, it exhibits excellent catalytic performance in terms of conversion rate, hydrogen storage capacity, and hydrogenation rate. Furthermore, the catalytic performance remains stable after regeneration and can be recycled multiple times, effectively reducing the preparation cost and industrial application cost of the catalytic material, demonstrating good economic efficiency and application prospects. Attached Figure Description

[0018] Figure 1 The image shows the XRD pattern of the alumina matrix prepared in Example 1.

[0019] Figure 2 The image shows the pore size distribution of the catalytic material prepared in Example 1.

[0020] Figure 3 The curves showing the changes in the composition of NEC, 4H-NEC, 8H-NEC, and 12H-NEC over time during a single hydrogenation of NEC by the catalyst material prepared in Example 1.

[0021] Figure 4 The curve showing the change in hydrogen addition amount over time for the NEC cycle hydrogenation before regeneration of the catalyst material prepared in Example 1.

[0022] Figure 5 The curve showing the change in hydrogen addition amount over time for NEC cycle hydrogenation after regeneration of the catalyst material prepared in Example 1. Detailed Implementation

[0023] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0024] Example 1

[0025] 1000 g of boehmite was dissolved in 4000 g of 12 wt% nitric acid aqueous solution to obtain aluminum sol. The aluminum sol was mixed with 19 g of silica sol and 19 g of cerium nitrate, and then 50 g of hexamethylenetetramine was added to obtain a slurry. After drop ball forming, it was dried at 110 ℃ for 5 h and calcined at 1000 ℃ for 5 h to obtain a silica- and cerium oxide modified composite alumina matrix 1. 900 g of nickel nitrate, 23 g of ammonium molybdate, and 50 g of zinc nitrate were dissolved in 480 g of water. After complete dissolution, 2.2 g of ethylenediaminetetraacetic acid was added and stirred evenly to form a complex impregnation solution. The composite alumina matrix 1 was impregnated using an equal-volume impregnation method to obtain a catalytic precursor 1. After drying at 100 ℃ for 3 h, calcined at 190 ℃ for 2 h and calcined at 350 ℃ for 2 h, and reduced at 450 ℃ under a hydrogen atmosphere. h, to obtain N-ethylcarbazole full hydrogenation catalyst 1.

[0026] Example 2

[0027] 200 g of aluminum isopropoxide was dissolved in 1000 g of 15 wt% nitric acid aqueous solution to obtain aluminum sol. The aluminum sol was mixed with 3.5 g of silica sol and 5 g of cerium nitrate, and then 8 g of polyethylene glycol was added to obtain a slurry. After drop ball molding, it was dried at 110 ℃ for 5 h and calcined at 950 ℃ for 5 h to obtain a silica- and cerium oxide modified composite alumina matrix 2. 170 g of nickel nitrate and 18 g of copper nitrate were dissolved in 105 g of water. After complete dissolution, 1.3 g of citric acid was added and stirred evenly to form a complex impregnation solution. The composite alumina matrix 2 was impregnated by the equal volume impregnation method to obtain the catalyst precursor 2. After drying at 100 ℃ for 4 h, it was calcined at 190 ℃ for 2 h and calcined at 330 ℃ for 2 h in sequence. Then it was reduced at 520 ℃ for 3 h under a hydrogen atmosphere to obtain N-ethylcarbazole full hydrogenation catalyst 2.

[0028] Example 3

[0029] 500 g of alumina was dissolved in 2000 g of 10 wt% hydrochloric acid aqueous solution to obtain an alumina sol. The alumina sol was mixed with 8 g of silica sol and 21 g of cerium nitrate, and then 25 g of hexamethylenetetramine was added to obtain a slurry. After drop ball forming, the slurry was dried at 95 ℃ for 8 h and calcined at 1100 ℃ for 3 h to obtain a silica- and cerium oxide modified composite alumina matrix 3. 350 g of nickel acetate and 65 g of cobalt nitrate were dissolved in 330 g of water. After complete dissolution, 9.5 g of tartaric acid was added and stirred evenly to form a complex impregnation solution. The composite alumina matrix 3 was impregnated using an equal volume impregnation method to obtain a catalyst precursor 3. After drying at 100 ℃ for 3 h, calcined at 210 ℃ for 2 h and calcined at 330 ℃ for 2 h in sequence, and reduced at 470 ℃ for 3 h under a hydrogen atmosphere, N-ethylcarbazole full hydrogenation catalyst 3 was obtained.

[0030] Example 4

[0031] 600 g of boehmite and 400 g of aluminum isopropoxide were added to 7000 g of 8 wt% nitric acid aqueous solution to obtain an aluminum sol. The aluminum sol was mixed with 7 g of silica sol and 10 g of cerium nitrate, and then 80 g of polyvinyl alcohol was added to obtain a slurry. After drop ball molding, the slurry was dried at 120 ℃ for 3 h and calcined at 1000 ℃ for 4 h to obtain a silica- and cerium oxide modified composite alumina matrix 4. 590 g of nickel nitrate and 36 g of copper nitrate were dissolved in 480 g of water. After complete dissolution, 2.5 g of triethylene glycol was added and stirred evenly to form a complex impregnation solution. The composite alumina matrix 4 was impregnated by an equal volume impregnation method to obtain a catalyst precursor 4. After drying at 100 ℃ for 3 h, calcined at 200 ℃ for 2 h and calcined at 350 ℃ for 2 h in sequence, and reduced at 450 ℃ for 3 h under a hydrogen atmosphere, N-ethylcarbazole full hydrogenation catalyst 4 was obtained.

[0032] Example 5

[0033] 170 g of boehmite and 30 g of aluminum isopropoxide were added to 800 g of 8 wt% nitric acid aqueous solution to obtain aluminum sol. The aluminum sol was mixed with 5 g of silica sol and 8 g of cerium nitrate, and then 5 g of hexamethylenetetramine was added to obtain a slurry. After drop ball forming, it was dried at 110 ℃ for 5 h and calcined at 100 ℃ for 5 h to obtain a silica- and cerium oxide modified composite alumina matrix 5. 200 g of nickel acetate and 3 g of cobalt nitrate were dissolved in 100 g of water. After complete dissolution, 1.7 g of tartaric acid was added and stirred evenly to form a complex impregnation solution. The composite alumina matrix 5 was impregnated by the equal volume impregnation method to obtain the catalyst precursor 5. After drying at 100 ℃ for 3 h, it was calcined at 190 ℃ for 3 h and calcined at 350 ℃ for 2 h in sequence. Then it was reduced at 500 ℃ for 3 h in a hydrogen atmosphere to obtain N-ethylcarbazole full hydrogenation catalyst 5.

[0034] Example 6

[0035] 100 g of aluminum isopropoxide was dissolved in 500 g of 18 wt% hydrochloric acid aqueous solution to obtain aluminum sol. The aluminum sol was mixed with 0.8 g of silica sol and 2.6 g of cerium nitrate, and then 3.5 g of polyethylene glycol was added to obtain a slurry. After drop ball molding, it was dried at 100 ℃ for 5 h and calcined at 1000 ℃ for 6 h to obtain a silica- and cerium oxide modified composite alumina matrix 6. 140 g of nickel nitrate, 3.5 g of ammonium molybdate, and 5.5 g of zinc nitrate were dissolved in 50 g of water. After complete dissolution, 0.5 g of citric acid was added and stirred evenly to form a complex impregnation solution. The composite alumina matrix 6 was impregnated by the equal volume impregnation method to obtain the catalyst precursor 6. After drying at 85 ℃ for 4 h, it was calcined at 190 ℃ for 2 h and 350 ℃ for 2 h in sequence, and then reduced at 450 ℃ for 4 h under a hydrogen atmosphere to obtain N-ethylcarbazole full hydrogenation catalyst 6.

[0036] Comparative Example 1

[0037] 1000 g of boehmite was weighed, 20 g of nitric acid and 200 ml of deionized water were added, and the mixture was thoroughly kneaded and extruded. After drying at 110 °C for 5 h and calcining at 1000 °C for 5 h, an alumina matrix was obtained. A complex impregnation solution was prepared according to the method of Example 1, and the catalyst precursor was obtained by impregnation using the equal volume impregnation method. After drying at 100 °C for 3 h, the precursor was calcined at 190 °C for 2 h and calcined at 350 °C for 2 h in sequence, and then reduced at 450 °C for 4 h in a hydrogen atmosphere to obtain comparative catalyst 1.

[0038] Comparative Example 2

[0039] The composite alumina matrix 3 was prepared according to the method of Example 3. 350 g of nickel acetate was dissolved in 330 g of water, and the precursor of the catalyst was obtained by impregnation by equal volume impregnation method. After drying at 100 °C for 3 h, it was calcined at 210 °C for 2 h and calcined at 330 °C for 2 h in sequence. Then, it was reduced at 470 °C for 3 h in hydrogen atmosphere to obtain the comparative catalyst 2.

[0040] The physicochemical properties of the catalytic materials prepared in Examples 1-6 and Comparative Examples 1-2 are shown in Table 1.

[0041] Table 1 Physicochemical properties of the catalysts prepared in the examples and comparative examples

[0042]

[0043] The N-ethylcarbazole (NEC) single-stage hydrogenation performance of the catalysts prepared in Examples 1-6 and Comparative Examples 1-2 was evaluated using a 250ml high-pressure reactor. The hydrogenation reaction conditions were as follows: 0.3 g of catalyst, 3 g of NEC, and 100 ml of decahydronaphthalene were added to the high-pressure reactor, and the reaction was carried out under a hydrogen atmosphere at a pressure of 7 MPa and a temperature of 180 ℃ for 3 h. During the reaction, the reactant NEC undergoes hydrogenation to produce tetrahydro-N-ethylcarbazole (4H-NEC), octahydro-N-ethylcarbazole (8H-NEC), and dodecahydro-N-ethylcarbazole (12H-NEC). The hydrogenation products were analyzed using a Shimadzu GC-2014 gas chromatograph. Based on the GC detection data, the composition and content of NEC, 4H-NEC, 8H-NEC, and 12H-NEC in the hydrogenation products were calculated using the area normalization method. The NEC conversion rate and hydrogenation amount were calculated based on the composition and content of the hydrogenation products, and the hydrogenation rate was calculated based on the hydrogenation amount versus time curve. The evaluation results of the single-cycle hydrogenation performance of the catalysts prepared in Examples 1-6 and Comparative Examples 1-2 for NEC are shown in Table 2.

[0044] After the catalyst material prepared in Example 1 underwent a single-cycle hydrogenation performance evaluation, the reaction product was removed from the high-pressure reactor, and reactants and solvent were added again for a cyclic hydrogenation reaction. After three cycles of cyclic hydrogenation, the catalyst material was regenerated by washing with ethanol. The regeneration conditions were: vacuum drying at 60 °C for 4 h, calcination at 350 °C for 2 h, and reduction at 500 °C for 3 h under a hydrogen atmosphere. The regenerated catalyst material was then subjected to another three cycles of cyclic hydrogenation. The time-varying composition curves of NEC, 4H-NEC, 8H-NEC, and 12H-NEC of the catalyst material prepared in Example 1 during a single hydrogenation of NEC are shown below. Figure 3 As shown in the figures, the curves of hydrogen addition to the NEC cycle before and after regeneration versus time are respectively as follows: Figure 4 , Figure 5 As shown.

[0045] Table 2 shows the single-cycle hydrogenation performance evaluation results for Example 1 and Comparative Example 1. The results indicate that Example 1 achieved a 100% NEC conversion rate, 6 percentage points higher than Comparative Example 1, with a hydrogenation amount 0.86 percentage points higher and a hydrogenation rate 1.4 times that of Comparative Example 1. The nickel and additive loading processes were identical in Example 1 and Comparative Example 1. Example 1 used a modified alumina matrix obtained by drop ball molding, resulting in a catalyst material with a stepped macroporous distribution. Comparative Example 1 used an alumina matrix obtained by kneading extrusion molding, resulting in a catalyst material with an average pore size of 6.6 nm. Figure 3 In Example 1, during a single hydrogenation reaction, the reactant NEC rapidly hydrogenated within 30 minutes of the reaction starting. The resulting intermediates 4H-NEC and 8H-NEC were then rapidly converted into the fully hydrogenated product 12H-NEC. This demonstrates that the stepped macroporous structure can improve the mass transfer process of the N-ethylcarbazole hydrogenation reaction system, thus significantly improving the hydrogenation performance of the catalytic material.

[0046] The single-cycle hydrogenation performance evaluation results of Example 3 and Comparative Example 2 in Table 2 show that the NEC conversion rate of Example 3 is 3 percentage points higher than that of Comparative Example 2, the hydrogenation amount is 0.18 percentage points higher, and the hydrogenation rate is 1.2 times that of Comparative Example 2. Example 3 and Comparative Example 2 used the same alumina matrix with a stepped macroporous distribution. Comparative Example 2 only loaded nickel, while Example 3 loaded nickel and the auxiliary cobalt oxide through a complex impregnation solution, thus achieving better catalytic hydrogenation performance.

[0047] The catalyst material prepared in Example 1 underwent three cycles of reaction, as shown in Table 3 and... Figure 4 The results show that the NEC conversion rate remains at 100%, the hydrogenation amount decreases by 0.21 percentage points, and the hydrogenation rate decreases by 18%. After regeneration treatment, Table 3 and... Figure 5 The results showed that the NEC conversion rate remained at 100% after regeneration, and the hydrogenation amount and rate were slightly higher than before regeneration. This indicates that the stepped macroporous distribution of the alumina matrix is ​​conducive to the redispersion of nickel in the pores during regeneration, which improves the utilization rate of nickel and makes the catalytic material exhibit good regeneration stability, so that it can be recycled for the N-ethylcarbazole catalytic hydrogenation process.

[0048] Table 2. Evaluation results of the catalyst materials prepared in the examples and comparative examples for single hydrogenation performance on NEC.

[0049]

[0050] Table 3. Evaluation results of the cyclic hydrogenation performance of the catalyst material prepared in Example 1 before and after regeneration.

[0051] .

Claims

1. A nickel-based catalyst for the complete hydrogenation of N-ethylcarbazole, characterized in that, The catalyst comprises an alumina matrix, a main active component (nickel), silicon oxide, cerium oxide, and an auxiliary component supported on the alumina matrix. Based on the total mass of the catalyst material (100%), the loading of the main active component (nickel) is 10.0-25.0 wt%, the loading of the silicon oxide is 0.05-1.00 wt%, the loading of the cerium oxide is 0.05-2.00 wt%, and the auxiliary component is one or more of molybdenum oxide, cobalt oxide, zinc oxide, and copper oxide, with a loading of 0.05-10.00 wt%. The remainder is the alumina matrix, which is a composite matrix of n-type and θ-type alumina. The catalyst material has a stepped pore distribution with an average pore size of 20.0-30.0 nm. The pore volume of pores with a diameter of 20.0-35.0 nm accounts for 35-45% of the total pore volume, and the pore volume of pores with a diameter of 35.0-45.0 nm is... The pore volume of nm-sized pores accounts for 20-45% of the total pore volume, with a pore volume of 0.50-1.20 cm³. 3 / g, specific surface area is 70-150 m² 2 / g.

2. A method for preparing the nickel-based catalyst for the complete hydrogenation of N-ethylcarbazole as described in claim 1, characterized in that, Includes the following steps: Aluminum source is added to acid solution to obtain aluminum sol. Aluminum sol is mixed with silica sol and cerium nitrate, and then template agent is added to obtain slurry. After drop ball molding, it is dried and calcined to obtain alumina matrix modified with silica and cerium oxide. Dissolve the soluble salt containing the active component nickel and the precursor of the auxiliary component in water, stir evenly, and then add organic acid and / or alcohol complexing agent to form a complex impregnation solution. The alumina matrix was impregnated in a complex impregnation solution using an equal-volume impregnation method to obtain a catalytic material precursor; The catalyst precursor was subjected to drying, calcination, and hydrogen reduction treatment in sequence to obtain a nickel-based catalyst for the full hydrogenation of N-ethylcarbazole.

3. The method for preparing the nickel-based catalyst for the complete hydrogenation of N-ethylcarbazole according to claim 2, characterized in that, The aforementioned drying and calcination process after drop ball formation consists of drying at 90-130 ℃ for 2-10 h and calcining at 900-1200 ℃ for 2-6 h. The process of drying, calcining, and hydrogen reduction of the catalytic material precursor is as follows: drying at 80-130 ℃ for 1-5 h, calcining at 150-220 ℃ for 1-3 h, calcining at 300-400 ℃ for 1-3 h, and reduction at 400-550 ℃ for 2-5 h in a hydrogen atmosphere.

4. The method for preparing the nickel-based catalyst for the complete hydrogenation of N-ethylcarbazole according to claim 2, characterized in that, The aluminum source is one or more of boehmite, aluminum isopropoxide, aluminum chloride, and aluminum oxide; The ratio of the amount of acid added to the mass of the aluminum source is (3-10):1, the mass fraction of the acid is 5-20 wt%, and the acid is one or more of hydrochloric acid, nitric acid, and sulfuric acid aqueous solution. The amount of template agent added is 0.1-10.0% of the mass of the aluminum source, and the template agent is one or more of hexamethylenetetramine, polyvinyl alcohol, and polyethylene glycol.

5. The method for preparing the nickel-based catalyst for the complete hydrogenation of N-ethylcarbazole according to claim 2, characterized in that, The precursor of the auxiliary component includes one or more of the following: ammonium molybdate, soluble salts of cobalt, soluble salts of zinc, and soluble salts of copper.

6. The method for preparing the nickel-based catalyst for the complete hydrogenation of N-ethylcarbazole according to claim 2, characterized in that, The amount of organic acid and / or alcohol complexing agent added is 0.5-20.0% of the mass of the main active component nickel. The organic acid complexing agent is one or more of tartaric acid, ethylenediaminetetraacetic acid, and citric acid, and the organic alcohol complexing agent is triethylene glycol.

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