Preparation method of nano Ni catalyst and its application

Abstract

The present invention discloses a method for preparing a nano-Ni catalyst. A prepared conductive gel is pressed into a stainless steel tube, allowed to stand, and dried. An aqueous solution containing a soluble nickel salt is then added to the tube. A platinum electrode is inserted, and current is applied for electrodeposition. After deposition is complete, the solution is removed, washed, and dried to obtain the nano-Ni catalyst. The catalyst prepared by this invention can be used as a hydrogenation catalyst for the preparation of toluene diaminodiphenyl (TDA) from dinitrotoluene (DNT), offering advantages such as high yield and low cost.

Description

Technical Field

[0001] The invention relates to a preparation method of a nano Ni catalyst and application of the nano Ni catalyst as a hydrogenation catalyst for preparing diaminotoluene (TDA) from dinitrotoluene (DNT) as a raw material. Background Art

[0002] Toluenediamine (TDA) is an intermediate in the preparation of toluene diisocyanate (TDI), and TDI is an important primary product in the preparation of polyurethane (PU). Polyurethane is widely used in industries such as elastomers, foam plastics, coatings, adhesives and fibers.

[0003] The current mainstream method for TDA synthesis is liquid-phase catalytic hydrogenation. There are two main catalysts used in liquid-phase hydrogenation technology to prepare TDA. One is a supported Pd / C or Pt / C noble metal catalyst, which has the advantages of high hydrogenation activity, low reaction pressure (1 MPa), and the absence of an external solvent. However, this catalyst is expensive, prone to carbon accumulation or poisoning, leading to deactivation, and difficult to separate. The other is a Raney nickel-based catalyst, which has the advantages of low price and simple separation. However, this catalyst requires a high reaction pressure (2 MPa), large equipment investment, and the need for continuous catalyst exhaust, resulting in catalyst loss.

[0004] Patent CN103977818A discloses a method for preparing a Raney nickel catalyst for low-pressure hydrogenation of dinitrotoluene. Specifically, nickel, aluminum, and a metal additive are melted and atomized to produce an alloy powder, which is then activated with alkali and ultrasonically cleaned to obtain the catalyst. This catalyst exhibits low reaction pressure and good activity. However, the alloy powder requires screening, and fine powder cannot be utilized, increasing catalyst costs. The activation process uses NaOH, which produces a large amount of alkali wastewater, resulting in high post-processing costs.

[0005] Patent CN102580748A discloses a method for preparing an amorphous Ni-B catalyst supported on SiO2. Specifically, a soluble metal salt solution is mixed with a water-soluble silicon source to prepare a NiO / SiO2 precursor, which is then reduced with a KBH4 solution. The catalyst prepared by this method has good hydrogenation activity, but methanol or ethanol needs to be added as a solvent. In addition, in the process of obtaining the precursor, the gel formed is crushed and screened, and the silica gel below 300 mesh is not used, resulting in waste. At the same time, the reducing agent reduces Ni 2+ The ionization occurs in the solution, causing part of the Ni to fall off, affecting the Ni content in the catalyst and thus affecting the catalyst activity.

[0006] CN102274724A discloses a method for preparing a highly active aromatic compound hydrogenation catalyst. The catalyst uses graphene as a carrier and Pt as an active component, and its production cost is very high.

[0007] Based on the defects in the above-mentioned prior art, it is necessary to seek a new catalyst for dinitrotoluene hydrogenation, provide a new catalyst form, avoid the use of expensive precious metal catalysts, and at the same time improve the utilization rate of active ingredients and reduce catalyst consumption. Summary of the Invention

[0008] The present invention aims to provide a method for preparing a nano-Ni catalyst. The catalyst obtained by the present invention has high activity, is not easy to lose, is easy to load and unload, does not require activation, and does not generate a large amount of alkaline wastewater.

[0009] To achieve the above objectives, the technical solutions of the present invention are as follows:

[0010] A method for preparing a nano-Ni catalyst comprises:

[0011] Optional (1), take a section of stainless steel pipe, pickle its inner surface, wash with water, wash with alcohol, and dry; and:

[0012] (2) Mixing silicate with alcohol (methanol and / or ethanol) and acid (hydrochloric acid and / or sulfuric acid), and adding component A (one or more selected from 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and acrylic acid (AA)) and component B (one or more selected from acrylamide, hydroxyethyl methacrylate, and polyvinyl alcohol) to obtain a mixed solution, adding a certain amount of graphite powder, ultrasonically stirring, and standing to obtain a gel;

[0013] (3) Press the prepared gel into a stainless steel tube, maintain a certain pressure, let it stand, and then blow it;

[0014] (4) A nickel salt (one or more selected from nickel chloride, nickel nitrate, and nickel acetate) is prepared into an aqueous solution of a certain concentration, added to the treated stainless steel tube, and a platinum electrode is inserted. Electric current is applied for electrodeposition. After deposition is completed, the solution is drained, washed, dried, and filled with nitrogen for protection.

[0015] In the present invention, in step (1), the inner diameter of the stainless steel tube is 2-10 cm, preferably 4-8 cm, and the length is 20-100 cm, preferably 40-80 cm;

[0016] The pickling solution is a 5-10wt% nitric acid and / or hydrochloric acid aqueous solution, and the alcohol washing solution is ethanol and / or methanol. The cleaning effect is based on cleaning the dirt on the inner wall of the stainless steel tube.

[0017] In the present invention, in step (2), the silicate is selected from ethyl orthosilicate and / or propyl orthosilicate;

[0018] The acid concentration is 1-3 mol / L.

[0019] The mass ratio of silicate, alcohol and acid added is 1:1-5:0.1-0.5, preferably 1:2-3:0.2-0.3,

[0020] The mass ratio of component A to component B added is 1-4:1, preferably 2-3:1.

[0021] The ratio of the total mass of component A and component B to the total mass of (silicate ester+alcohol+acid) is 1-3:1;

[0022] The mass of the added graphite powder is 1-10 wt% of the mass of the mixed solution.

[0023] In the present invention, in step (2), in a specific embodiment, the silicate / ethanol / hydrochloric acid is stirred and mixed at a temperature of 50-70°C for 30-120 min, preferably 60-90 min. After the reaction solution cools to room temperature, component A, component B and graphite are added, stirred, and ultrasonically treated for 30-120 min, preferably 60-90 min, and allowed to stand to obtain a gel.

[0024] In the present invention, in step (3), the gel is injected into the stainless steel tube. To ensure that the gel is filled and evenly distributed, the stainless steel tube is kept under ultrasound during the operation. After the injection is completed, the pressure is increased to 20-40 MPa, and ultrasound is continued for 20-60 minutes. The tube is allowed to stand for natural decompression. After the pressure is released to normal pressure, nitrogen is introduced and purged, and the tube is dried for later use.

[0025] In the present invention, in step (4), the nickel salt concentration is 5-15wt%, and the weight of the nickel salt aqueous solution is 200-3000g, preferably 400-2000g. The length of the platinum electrode is slightly longer than the stainless steel tube to ensure that it penetrates the entire stainless steel tube to achieve a good electrodeposition effect. The electrodeposition current density is 30-200mA / cm 2 , preferably 60-150mA / cm 2 The deposition time is 1-4 hours, preferably 2-3 hours. After the deposition is completed, the solution is drained, washed, and dried. Nitrogen is filled for protection.

[0026] The present invention also relates to the use of the prepared catalyst as a hydrogenation catalyst for preparing diaminotoluene (TDA) using dinitrotoluene (DNT) as a raw material.

[0027] The positive effects of the present invention are:

[0028] 1. A conductive colloid was prepared to provide conductive attachment points and a conductive environment for the graphite particles mixed into it. Through electrodeposition, the active component Ni precipitated from the graphite particles, forming nano-sized elemental Ni. This highly active catalyst facilitates low-temperature and low-pressure reaction conditions, reduces reaction energy consumption, minimizes side reactions, and improves reaction yield. Furthermore, due to its high dispersion and small size, the amount of active component required is reduced, thus reducing catalyst costs.

[0029] 2. The catalyst is attached to the inner surface of the stainless steel tube, and the stainless steel tube can be directly connected to the reaction system to participate in the reaction. It is easy to disassemble and assemble, reducing the risk and cost of catalyst replacement.

[0030] 3. There is no need to activate the catalyst and no large amount of activation wastewater is generated. DETAILED DESCRIPTION

[0031] In order to better understand the present invention, the technical features of the present invention are further illustrated below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments.

[0032] <Source of raw materials>

[0033] Ethyl orthosilicate, propyl orthosilicate, Aladdin reagent;

[0034] Anhydrous ethanol, Tianjin Damao reagent;

[0035] Hydrochloric acid, Kermelo's reagent;

[0036] Acrylamide, Aladdin reagent;

[0037] 2-Acrylamido-2-methylpropanesulfonic acid (AMPS), Aladdin reagent;

[0038] Acrylic acid, Aladdin reagent

[0039] Hydroxyethyl methacrylate, Aladdin reagent

[0040] Polyvinyl alcohol, Aladdin reagent

[0041] Nickel chloride, Aladdin reagent

[0042] Nickel nitrate, Kermelo reagent

[0043] Nickel acetate, Kermelo reagent

[0044] Graphite powder, Kermel reagent

[0045] N,N-dimethylformamide (DMF), Kermelo reagent

[0046] Commercially available TDA catalyst, 6800, Evonik.

[0047] <Testing and Preparation Equipment>

[0048] The electrochemical workstation used in the embodiments of the present invention is a CHI660 electrochemical workstation produced by Shanghai Chenhua Instrument Co., Ltd.

[0049] The scanning electron microscope used in the embodiments of the present invention is a FESEM SU-8020 cold field emission scanning electron microscope manufactured by Hitachi High-Tech Corporation.

[0050] The gas chromatography analysis conditions used in the examples of the present invention were: an Agilent DB-5 column, an inlet temperature of 300°C, a detector temperature of 300°C, a H₂ flow rate of 35 ml / min, and an air flow rate of 350 ml / min. The column oven temperature program was: initial temperature -100°C, ramp rate of 20°C / min, hold for 1 min; 100-300°C, ramp rate of 15°C / min, hold for 8 min.

[0051] The hydrogenation reaction device used in the examples of the present invention was customized by Yantai Arteson Machinery Equipment Co., Ltd.

[0052] Example 1

[0053] A stainless steel tube with an inner diameter of 2 cm and a length of 25 cm was selected and cleaned with a 5% nitric acid solution for 1 hour, then with deionized water for 1 hour, and finally with ethanol for 1 hour, and then dried in a 90°C oven. 100 g of tetraethyl orthosilicate, 100 g of ethanol, and 10 g of 3 mol / L hydrochloric acid were added to a 1 L three-necked round-bottom flask and stirred in a 60°C water bath for 50 minutes. The heating and stirring were turned off. After the reaction solution cooled to room temperature, the round-bottom flask was placed in an ultrasonicator, and 105 g of 2-acrylamido-2-methylpropanesulfonic acid, 105 g of acrylamide, and 4.2 g of graphite powder were added. The mixture was stirred in an ultrasonic bath for 100 minutes and allowed to stand to obtain a gel.

[0054] Block one end of the stainless steel tube with a wire plug and place it in the ultrasonic chamber. Add the gel from the other end, adding as slowly as possible to avoid dead volume. After the addition is complete, connect the stainless steel tube to the pressurization device and slowly increase the pressure to 20 MPa. Continue ultrasonication for 40 minutes, then remove the tube and allow it to stand for natural decompression.

[0055] Weigh 30g of nickel chloride and 170g of water to prepare a nickel chloride aqueous solution. Pour the prepared solution into a stainless steel tube and insert a platinum electrode to start electrodeposition. The current density is 190mA / cm 2 The deposition time is 1 hour. After the deposition is completed, the solution is drained, washed, and dried. Nitrogen protection is filled.

[0056] A stainless steel tube was connected to a catalyst evaluation system and heated with electric heating tape wrapped around it. The feedstock consisted of a 40 wt% DNT solution in DMF. The feed rate was 4 ml / min, the hydrogen flow rate was 300 ml / min, the heating tape was set to 100°C, and the reaction pressure was 1 MPa. The initial amount of feedstock was 100 g, and the reaction solution was circulated through the reaction system for 12 hours. After completion, the reaction results were analyzed by gas chromatography. DNT conversion was 100%, light components were 0.25%, heavy components were 0.13%, and TDA yield was 99.62%.

[0057] Example 2

[0058] A section of stainless steel tubing with an inner diameter of 10 cm and a length of 100 cm was cleaned with a 9% nitric acid solution for 1 hour, followed by a 1-hour rinse with deionized water, and finally with ethanol. The tube was then dried in a 90°C oven. 100 g of propyl orthosilicate, 500 g of ethanol, and 50 g of 1 mol / L hydrochloric acid were added to a 5 L three-necked round-bottom flask. The mixture was stirred in a 55°C water bath for 80 minutes. The heating and stirring were then turned off. After the reaction solution cooled to room temperature, the round-bottom flask was placed in an ultrasonicator and 1560 g of acrylic acid, 200 g of hydroxyethyl methacrylate, 190 g of polyvinyl alcohol, and 260 g of graphite powder were added. The mixture was stirred under ultrasonication for 80 minutes and allowed to stand to obtain a gel.

[0059] Block one end of the stainless steel tube with a wire plug and place it in the ultrasonic chamber. Add the gel from the other end, adding as slowly as possible to avoid dead volume. After the addition is complete, connect the stainless steel tube to the pressurization device and slowly increase the pressure to 30 MPa. Continue ultrasonication for 55 minutes, then remove the tube and allow it to stand for natural decompression.

[0060] Weigh 150g of nickel nitrate and mix it with 2850g of water to make a nickel-containing aqueous solution. Pour the prepared solution into a stainless steel tube and insert a platinum electrode to start electrodeposition. The current density is 40mA / cm 2 The deposition time is 4 hours. After the deposition is completed, the solution is drained, washed, and dried. Nitrogen is filled for protection.

[0061] A stainless steel tube was connected to a catalyst evaluation system and heated with electric heating tape wrapped around it. The feedstock consisted of a 40 wt% DNT solution in DMF. The feed rate was 4 ml / min, the hydrogen flow rate was 300 ml / min, the heating tape was set to 100°C, and the reaction pressure was 1 MPa. The initial amount of feedstock was 100 g, and the reaction solution was circulated in the reaction system. The reaction time was 12 hours. After completion of the reaction, the results were analyzed by gas chromatography. DNT conversion was 100%, light components were 0.29%, heavy components were 0.11%, and TDA yield was 99.60%.

[0062] Example 3

[0063] A section of stainless steel tubing with an inner diameter of 4 cm and a length of 80 cm was cleaned with a 7% nitric acid solution for 1 hour, followed by a 1-hour rinse with deionized water, and finally an ethanol rinse. The tube was then oven-dried at 90°C. 100 g of propyl orthosilicate, 200 g of ethanol, and 20 g of 2 mol / L hydrochloric acid were added to a 3 L three-necked round-bottom flask. The mixture was stirred in a 60°C water bath for 60 minutes. The heating and stirring were then turned off. After the reaction solution cooled to room temperature, the round-bottom flask was placed in an ultrasonicator and 427 g of acrylic acid, 100 g of hydroxyethyl methacrylate, 113 g of acrylamide, and 57.6 g of graphite powder were added. The mixture was stirred under ultrasonication for 60 minutes and allowed to stand to obtain a gel.

[0064] Block one end of the stainless steel tube with a wire plug and place it in the ultrasonic chamber. Add the gel from the other end, adding as slowly as possible to avoid dead volume. After the addition is complete, connect the stainless steel tube to the pressurization device and slowly increase the pressure to 35 MPa. Continue ultrasonication for 40 minutes, then remove the tube and allow it to stand for natural decompression.

[0065] Weigh 36g of nickel acetate and mix it with 364g of water to make a nickel-containing aqueous solution. Pour the prepared solution into a stainless steel tube and insert a platinum electrode to start electrodeposition. The current density is 60mA / cm 2 The deposition time is 3 hours. After the deposition is completed, the solution is drained, washed, and dried. Nitrogen protection is filled.

[0066] A stainless steel tube was connected to a catalyst evaluation system and heated with electric heating tape wrapped around it. The feedstock consisted of a 40 wt% DNT solution in DMF. The feed rate was 4 ml / min, the hydrogen flow rate was 300 ml / min, the heating tape was set to 100°C, and the reaction pressure was 1 MPa. The initial amount of feedstock was 100 g, and the reaction solution was circulated through the reaction system for 12 hours. After completion, the reaction results were analyzed by gas chromatography. The DNT conversion was 100%, the light components were 0.28%, the heavy components were 0.13%, and the TDA yield was 99.59%.

[0067] Example 4

[0068] A section of stainless steel tubing with an inner diameter of 8 cm and a length of 40 cm was cleaned with 8% nitric acid solution for 1 hour, followed by 1 hour of deionized water and finally ethanol, then dried in a 90°C oven. 100 g of propyl orthosilicate, 300 g of ethanol, and 30 g of 1.5 mol / L hydrochloric acid were added to a 3L three-necked round-bottom flask. The mixture was stirred in a 65°C water bath for 90 minutes, and then the heat and stirring were turned off. After the reaction solution cooled to room temperature, the round-bottom flask was placed in an ultrasonicator and 774 g of acrylic acid, 200 g of hydroxyethyl methacrylate, 200 g of acrylamide, 116 g of polyvinyl alcohol, and 137.6 g of graphite powder were added. The mixture was stirred under ultrasonication for 90 minutes and allowed to stand to obtain a gel.

[0069] Block one end of the stainless steel tube with a wire plug and place it in the ultrasonic chamber. Add the gel from the other end, adding as slowly as possible to avoid dead volume. After the addition is complete, connect the stainless steel tube to the pressurization device and slowly increase the pressure to 25 MPa. Continue ultrasonication for 45 minutes, then remove the tube and allow it to stand for natural decompression.

[0070] Weigh 220g of nickel acetate and mix it with 1780g of water to make a nickel-containing aqueous solution. Pour the prepared solution into a stainless steel tube and insert a platinum electrode to start electrodeposition. The current density is 150mA / cm 2 The deposition time is 2 hours. After the deposition is completed, the solution is drained, washed, and dried. Nitrogen protection is filled.

[0071] A stainless steel tube was connected to a catalyst evaluation system and heated with electric heating tape wrapped around it. The feedstock consisted of a 40 wt% DNT solution in DMF. The feed rate was 4 ml / min, the hydrogen flow rate was 300 ml / min, the heating tape was set to 100°C, and the reaction pressure was 1 MPa. The initial amount of feedstock was 100 g, and the reaction solution was circulated through the reaction system for 12 hours. After completion, the reaction results were analyzed by gas chromatography. DNT conversion was 100%, light components were 0.25%, heavy components were 0.13%, and TDA yield was 99.62%.

[0072] Example 5

[0073] A section of stainless steel tubing with an inner diameter of 6 cm and a length of 60 cm was cleaned with a 7% nitric acid solution for 1 hour, followed by a 1-hour rinse with deionized water, and finally with ethanol. The tubing was then oven-dried at 90°C. 100 g of propyl orthosilicate, 250 g of ethanol, and 25 g of 2 mol / L hydrochloric acid were added to a 3 L three-necked round-bottom flask. The mixture was stirred in a 55°C water bath for 75 minutes. The heating and stirring were then turned off. After the reaction solution cooled to room temperature, the flask was placed in an ultrasonicator and 669.6 g of acrylic acid, 167.9 g of hydroxyethyl methacrylate, 100 g of polyvinyl alcohol, and 91.9 g of graphite powder were added. The mixture was stirred under ultrasonication for 75 minutes and allowed to stand to obtain a gel.

[0074] Block one end of the stainless steel tube with a wire plug and place it in the ultrasonic chamber. Add the gel from the other end, adding as slowly as possible to avoid dead volume. After the addition is complete, connect the stainless steel tube to the pressurization device and slowly increase the pressure to 35 MPa. Continue ultrasonication for 40 minutes, then remove the tube and allow it to stand for natural decompression.

[0075] Weigh 156g of nickel acetate and mix it with 1044g of water to make a nickel-containing aqueous solution. Pour the prepared solution into a stainless steel tube and insert a platinum electrode to start electrodeposition. The current density is 110mA / cm 2 The deposition time was 2.5 hours. After the deposition was completed, the solution was drained, washed, and dried. Nitrogen was filled for protection.

[0076] A stainless steel tube was connected to a catalyst evaluation system and heated with electric heating tape wrapped around it. The feedstock consisted of a 40 wt% DNT solution in DMF. The feed rate was 4 ml / min, the hydrogen flow rate was 300 ml / min, the heating tape was set to 100°C, and the reaction pressure was 1 MPa. The initial amount of feedstock was 100 g, and the reaction solution was circulated through the reaction system for 12 hours. After completion, the reaction results were analyzed by gas chromatography. The DNT conversion was 100%, the light components were 0.24%, the heavy components were 0.13%, and the TDA yield was 99.63%.

[0077] Comparative Example 1 (Compared with Example 5)

[0078] A section of stainless steel tubing with an inner diameter of 6 cm and a length of 60 cm was selected and rinsed with a 7% nitric acid solution for 1 hour, followed by a 1-hour rinse with deionized water, and finally an ethanol rinse for 1 hour. The tubing was then placed in a 90°C oven to dry. 100 g of propyl orthosilicate, 250 g of ethanol, and 25 g of 2 mol / L hydrochloric acid were added to a 3L three-necked round-bottom flask. The mixture was stirred in a 55°C water bath for 75 minutes, and the heating and stirring were turned off. After the reaction solution cooled to room temperature, the round-bottom flask was placed in an ultrasonicator and charged with 669.6 g of acrylic acid, 167.9 g of hydroxyethyl methacrylate, 100 g of polyvinyl alcohol, and 51.8 g (calculated based on complete conversion of the nickel in the nickel acetate to elemental nickel) of commercially available 6800 catalyst. The mixture was stirred in an ultrasonic bath for 75 minutes and allowed to stand to obtain a catalyst-containing gel.

[0079] Block one end of the stainless steel tube with a wire plug and place it in an ultrasonic bath. Add the gel from the other end, adding as slowly as possible to avoid dead volume. After addition is complete, connect the stainless steel tube to a pressurizing device and slowly increase the pressure to 35 MPa. Continue ultrasonicating for 35 minutes, remove the tube, and allow it to stagnate naturally. Drain the solution, wash, and dry. Fill with nitrogen for protection.

[0080] A stainless steel tube was connected to the catalyst evaluation system and heated with electric heating tape wrapped around it. The feed liquid consisted of a 40 wt% DNT solution in DMF. The feed rate was 4 ml / min, the hydrogen flow rate was 300 ml / min, the heating tape was set to 100°C, and the reaction pressure was 1 MPa. The initial amount of feed liquid was 100 g, and the reaction liquid was circulated in the reaction system for 12 hours. After completion, the reaction results were analyzed by gas chromatography. The DNT conversion was 88%, the light components were 0.22%, the heavy components were 2.26%, and the TDA yield was 80.54%. This indicates that the commercially available catalyst performed poorly in this system, as the nano-Ni catalyst was not formed through electrodeposition.

Claims

1. A method for preparing a nano-Ni catalyst, characterized in that: The method comprises: (1) Take a section of stainless steel pipe, clean its inner surface and dry it; (2) mixing silicate with alcohol and acid, and adding component A and component B to obtain a mixed solution, adding a certain amount of graphite powder, ultrasonically stirring, and standing to obtain a gel; wherein component A is selected from 2-acrylamido-2-methylpropanesulfonic acid and acrylic acid, and component B is selected from acrylamide, hydroxyethyl methacrylate, and polyvinyl alcohol; (3) Press the prepared gel into a stainless steel tube, maintain a certain pressure, let it stand, and then blow it; (4) Add nickel salt aqueous solution into the stainless steel tube, insert the electrode, and apply power for electrodeposition. After the deposition is completed, drain the solution, wash, and dry.

2. The method according to claim 1, wherein The inner diameter of the stainless steel tube is 2-10 cm and the length is 20-100 cm.

3. The method according to claim 1, wherein In step (2), the silicate is selected from ethyl orthosilicate and / or propyl orthosilicate; the alcohol is selected from methanol and / or ethanol; the acid is selected from hydrochloric acid and / or sulfuric acid, and the acid concentration is 1-3 mol / L; The mass ratio of silicate, alcohol and acid is 1:1-5:0.1-0.

5.

4. The method according to claim 3, wherein: In step (2), the mass ratio of silicate, alcohol and acid is 1:2-3:0.2-0.

3.

5. The method according to any one of claims 1 to 4, wherein: In step (2), the mass ratio of component A to component B is 1-4:1; The ratio of the total mass of component A+component B to the total mass of silicate+alcohol+acid is 1-3:

1.

6. The method according to any one of claims 1 to 4, wherein: In step (2), the mass of graphite powder is 1-10 wt % of the mass of the mixed solution.

7. The method according to any one of claims 1 to 4, wherein: In step (2), the silicate is mixed with the alcohol and the acid at a temperature of 50-70° C. for 30-120 min.

8. The method according to claim 1, wherein In step (3), the gel is injected into the stainless steel tube, and the stainless steel tube is always under ultrasound during the operation; After the injection is completed, the pressure is charged to 20-40MPa, and ultrasonication is continued for 20-60 minutes. The pressure is allowed to stand and naturally release. After the pressure is released to normal pressure, nitrogen is introduced for purging.

9. The method according to any one of claims 1 to 4, wherein: In step (4), the nickel salt is selected from nickel chloride, nickel nitrate, and nickel acetate, the concentration of the nickel salt aqueous solution is 5-15wt%, and the weight of the nickel salt aqueous solution is 200-3000g.

10. The method according to any one of claims 1 to 4, wherein: In step (4), the electrodeposition current density is 30-200 mA / cm 2 , the deposition time is 1-4hr.

11. The method according to claim 10, wherein: In step (4), the electrodeposition current density is 60-150 mA / cm 2 .

12. Use of the catalyst obtained by the preparation method according to any one of claims 1 to 11 as a hydrogenation catalyst for preparing diaminotoluene using dinitrotoluene as a raw material.