A ni-based catalyst for preparing hexamethylenediamine by reducing amination of hexandiol and a preparation method thereof

Abstract

The application discloses a Ni-based catalyst for preparing hexamethylenediamine through reductive amination of hexanediol and a preparation method thereof, and belongs to the technical field of catalysts. The Ni-based catalyst for preparing hexamethylenediamine through reductive amination of hexanediol is composed of an active component Ni and a carrier, wherein the carrier is AlPO x modified active Al2O3, and 0 x is prepared by reacting an organic phosphine with active Al2O3. The Ni-based catalyst is prepared by AlPO x modification of Al2O3, so that the carrier AlPO x -Al2O3 and the active component Ni interact with each other, the catalytic activity of the Ni-based catalyst for preparing hexamethylenediamine through reductive amination of hexanediol is significantly improved, the selectivity of hexamethylenediamine is improved, the yield of hexamethylenediamine is higher, and the production cost of hexamethylenediamine is significantly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalysts, in particular to a Ni-based catalyst for preparing hexamethylene diamine by reductive amination of hexanediol and a preparation method thereof. BACKGROUND

[0002] Hexamethylene diamine, also known as 1,6-hexanediamine, is widely used in many industries.

[0003] In the chemical industry, hexamethylene diamine is an important chemical intermediate, which is widely used in the production of polyamides such as nylon 66, nylon 610, nylon 612 and nylon 69, hexamethylene diisocyanate, epoxy resin curing agent, organic crosslinking agent, etc. In the petroleum industry, hexamethylene diamine can be used as a surfactant in the process of oil extraction. After chemical modification, hexamethylene diamine can combine with oil in oil to form an emulsion, improving the efficiency of oil extraction. In the agricultural industry, hexamethylene diamine can be used as an efficient insecticide, widely used in large-scale farmland protection and single-plant protection of fruit trees, vegetables, etc. Hexamethylene diamine can kill various pests and viruses, protecting the yield and quality of crops. In the dye industry, hexamethylene diamine is an important intermediate raw material. Through the processing of hexamethylene diamine, various organic dyes can be obtained, which are used for dyeing and printing of fabrics, paper, leather and other materials. In the pharmaceutical industry, hexamethylene diamine can be used as a raw material for various drugs, such as antibiotics, alkaloids, anesthetics, etc. At the same time, hexamethylene diamine can also be used as an intermediate for the synthesis of various drugs. In short, hexamethylene diamine, as a widely used chemical raw material, plays an indispensable role in petroleum, pesticide, dye, pharmaceutical and many other industries.

[0004] In the prior art, hexamethylene diamine is often prepared by reductive amination of hexanediol, which is low in cost and environmentally friendly. However, the conversion rate of hexanediol and the selectivity of hexamethylene diamine are relatively low, and the yield of hexamethylene diamine is not high. For example, patent US4014933A uses activated 10%CoO-10%NiO-4%CuO / Al2O3 as catalyst, 100 parts of 80% hexanediol aqueous solution per hour, 350 parts of liquid ammonia, hydrogen gas is pumped in at 220℃ to 30MPa, the conversion rate of hexanediol is close to 100%, and the yield of hexamethylene diamine is 23%. Luo and An et al. reported in ACS Sustainable Chem. Eng. 2022, 10, 13367-13379 that NiCu / MgAlO alloy derived from hydrotalcite structure catalyzed the reductive amination of hexanediol to prepare hexamethylene diamine, at 180℃, the conversion rate was 77%, the selectivity of hexamethylene diamine was 20%, and the yield of hexamethylene diamine was only 15.4%.

[0005] In order to solve the above-mentioned problems of low yield and poor selectivity of hexamethylene diamine, researchers introduced noble metals into the catalyst for preparing hexamethylene diamine by reducing amination of hexylene glycol. Although the yield and selectivity of hexamethylene diamine are improved, the noble metal is expensive, which still has great difficulty in practical application. For example, patent CN116178168A discloses a non-uniform catalyst composed of a core and an outer layer. The core and the outer layer are both composed of a carrier and a limited amount of active metal (one or more of Co, Ni, Cu) and an additive (one or more of Ru, Pd, Fe, B, Zn, Re, W, Y, etc. metal or oxide). For example, the 20Ni10Co2.5Re2B / 3Ni1Co0.6B-Al2O3 catalyst catalyzes the reducing amination of hexylene glycol. First, the Al2O3 is impregnated with the precursors of Ni, Co, Re and B at the same time, and then Ni, Co, Re and B are loaded again after calcination. Among them, the liquid volume space velocity of hexylene glycol is 0.6h -1 , the molar ratio of ammonia: hexylene glycol: hydrogen is 16:1:0.7, the conversion rate of hexylene glycol is 90.5%, the selectivity of hexamethylene diamine is 93.5%, and the yield of hexamethylene diamine is 84.6%. However, the catalyst uses the noble metal catalyst Re, which is expensive. When using the catalyst 20Ni10Co / 3Ni1Co-Al2O3 without Re under the same reaction conditions, the conversion rate is 46.7%, the selectivity of hexamethylene diamine is 23.2%, and the yield of hexamethylene diamine is only 10.8%.

[0006] In order to reduce the production cost, researchers propose to use a secondary amine inhibitor to prepare a catalyst for preparing hexamethylene diamine by reducing amination of hexylene glycol. For example, patent CN115772087A provides a method for preparing hexamethylene diamine by reducing amination of hexylene glycol, which uses a secondary amine inhibitor and a method of pre-activating the catalyst to improve the reaction performance. The catalyst is a Ni / ZrO2 / Al2O3 catalyst, which is pre-activated with ammonia. The secondary amine inhibitor is water, ammonia or urea. The conversion rate is 94.38%, the selectivity of hexamethylene diamine is 94.68%, and the yield of hexamethylene diamine is 89.4%. However, the use of a secondary amine inhibitor increases the difficulty of separation, which is not conducive to industrial production.

[0007] Therefore, it is of great significance to research a new Ni-based catalyst for preparing hexamethylene diamine by reducing amination of hexylene glycol for the preparation and application of hexamethylene diamine. SUMMARY

[0008] Therefore, the technical problem to be solved by the present application is to provide a Ni-based catalyst for preparing hexamethylene diamine by reducing amination of hexylene glycol and a preparation method thereof. The Ni-based catalyst for preparing hexamethylene diamine by reducing amination of hexylene glycol has high catalytic activity and selectivity and yield of hexamethylene diamine, and reduces the production cost of hexamethylene diamine.

[0009] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0010] The present application provides a Ni-based catalyst for preparing hexamethylenediamine by reductive amination of hexandiol, which is composed of active component Ni and carrier.

[0011] The carrier is AlPO x The active Al2O3 is modified.

[0012] Preferably, 0

[0013] Preferably, the AlPO x The active Al2O3 is prepared by reacting organic phosphine and active Al2O3.

[0014] The reaction is high-temperature reaction and reduction reaction.

[0015] The temperature of the high-temperature reaction is preferably 400-700℃.

[0016] The Ni-based catalyst for preparing hexamethylenediamine by reductive amination of hexandiol is represented as Ni / AlPO x -Al2O3.

[0017] Preferably, the AlPO x -Al2O3 represents the carrier, i.e. AlPO x The active Al2O3 is modified.

[0018] The carrier AlPO x -Al2O3 is prepared by reacting AlPO x The modification of the active Al2O3 makes the carrier AlPO x -Al2O3 interact with the active component Ni, which significantly improves the catalytic activity of the Ni-based catalyst (Ni / AlPO x -Al2O3) for preparing hexamethylenediamine by reductive amination of hexandiol and the selectivity of hexamethylenediamine.

[0019] Preferably, the loading amount of the active component Ni is 5-15wt%, more preferably 7-13wt%. In some specific embodiments of the present application, the loading amount of the active component Ni is 10wt% or 12.5wt%.

[0020] Preferably, the organic phosphine is selected from one or more of triphenylphosphine, triphenylphosphine oxide, sodium triphenylphosphine sulfonate, tri-tert-butylphosphine, trimethylphosphine, tributylphosphine, trihexylphosphine, trioctylphosphine, trifurfurylphosphine, tritolylphosphine, triphenyl ether phosphine and trifluorophenylphosphine.

[0021] The catalyst of the present application is a supported non-noble metal Ni-based catalyst, which is easy to obtain and simple to prepare.

[0022] The application also provides a preparation method of a Ni-based catalyst for preparing hexamethylenediamine by reductive amination of hexanediol, comprising the following steps:

[0023] The Ni-based catalyst for preparing hexamethylenediamine by reductive amination of hexanediol is prepared by impregnating a nickel precursor and an organic phosphine on the surface of active Al2O3 and then performing a hydrogen reduction reaction.

[0024] In the above preparation method, the nickel precursor forms active Ni under the hydrogen reduction condition.

[0025] The organic phosphine and the active Al2O3 react to form AlPO4-Al2O3 through a high-temperature reaction and a reduction reaction. x

[0026] The above preparation method prepares the Ni-based catalyst for preparing hexamethylenediamine by reductive amination of hexanediol through a solution impregnation method and a hydrogen reduction method.

[0027] Preferably, the molar ratio of the nickel precursor to the organic phosphine is 1:(0.33-3). In some specific embodiments of the application, the molar ratio of the nickel precursor to the organic phosphine is specifically 1:0.33 or 1:0.5 or 1:1 or 1:2 or 1:3.

[0028] Preferably, the hydrogen reduction reaction further comprises calcination before the hydrogen reduction reaction.

[0029] Preferably, the calcination temperature is 200-600°C; more preferably, 300°C.

[0030] The calcination is performed in an inert atmosphere.

[0031] The inert atmosphere includes but is not limited to nitrogen and argon.

[0032] Preferably, the nickel precursor is selected from metal salts of nickel.

[0033] Preferably, the metal salt of nickel is selected from one or more of nickel nitrate hexahydrate, nickel chloride hexahydrate and nickel sulfate hexahydrate.

[0034] Preferably, the hydrogen reduction reaction is performed at normal pressure.

[0035] Preferably, the hydrogen gas flow rate of the hydrogen reduction reaction is 10-30 mL / min.

[0036] Preferably, the temperature of the hydrogen reduction reaction is 400-700°C; more preferably, 500-600°C; in some specific embodiments of the application, the temperature is specifically 550°C.

[0037] ​The application also provides a preparation method of hexamethylene diamine, which uses the Ni-based catalyst for preparing hexamethylene diamine by reductive amination of hexylene glycol or the Ni-based catalyst prepared by the preparation method as a catalyst to perform reductive amination reaction to prepare hexamethylene diamine.

[0038] The Ni-based catalyst for preparing hexamethylene diamine by reductive amination of hexylene glycol is used to prepare hexamethylene diamine, hexylene glycol is substantially completely converted, and the yield of hexamethylene diamine is 46% to 60%. Preferably, the reductive amination reaction is performed by using ammonia gas.

[0039] Preferably, the pressure of the ammonia gas is 1 to 20 MPa, and more preferably 11 to 15 MPa. In some specific embodiments of the application, the pressure is specifically 11 MPa or 13 MPa.

[0040] Preferably, the temperature of the reductive amination reaction is 190°C to 250°C, and more preferably 210°C to 230°C. In some specific embodiments of the application, the temperature is specifically 220°C or 230°C.

[0041] Compared with the prior art, the Ni-based catalyst for preparing hexamethylene diamine by reductive amination of hexylene glycol consists of an active component Ni and a carrier AlPO x modified active Al2O3, wherein 0 < x < 4. The AlPO x is prepared by reacting an organic phosphine and active Al2O3. The Ni-based catalyst is prepared by the method, and the AlPO x modification of Al2O3 makes the carrier AlPO x The interaction between Al2O3 and the active component Ni significantly improves the catalytic activity of the Ni-based catalyst for preparing hexamethylene diamine by reductive amination of hexylene glycol and the selectivity of hexamethylene diamine, and has a higher yield of hexamethylene diamine. Moreover, the preparation method of the Ni-based catalyst is simple, raw materials are easy to obtain, and expensive noble metals and secondary amine inhibitors do not need to be used, thereby reducing the production cost of hexamethylene diamine and having a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The Ni / AlPO x Photoelectron spectroscopy of the Ni / AlPO DETAILED DESCRIPTION

[0043] In order to further illustrate the present application, the Ni-based catalyst for the reductive amination of hexanediol to prepare hexamethylenediamine and the preparation method thereof provided by the present application are described in detail below in combination with examples.

[0044] Example 1

[0045] Active Al2O3 was used as a catalyst carrier, and nickel nitrate and triphenylphosphine were impregnated on the carrier, and then the catalyst Ni / AlPO4-Al2O3 was formed by hydrogen reduction. x The loading amount of Ni was 10 wt%, and the amount of triphenylphosphine was 0.33 times the amount of substance of nickel nitrate, and the catalyst was obtained by hydrogen reduction at 550°C.

[0046] The above catalyst was used for the reductive amination of hexanediol, and the activity and selectivity of the catalyst were determined. The reaction was carried out in a 100 ml autoclave, 5 mmol of hexanediol, 6 ml of tert-butyl alcohol and 0.1 g of the catalyst were added into the autoclave, and after the autoclave was sealed, the gas space was purged with nitrogen and then with hydrogen, and finally 1 MPa of hydrogen pressure was formed. After heating to 220°C, 13 MPa of ammonia was pumped in, and the reaction was started by opening the mechanical stirring, and the reaction was carried out for 12.5 h. The reaction mixture was cooled, depressurized, filtered, and analyzed by gas chromatography, and the calibration factor was calibrated by preparing a standard sample; the conversion rate and selectivity were calculated based on the molar content of each component in the reaction liquid. The conversion rate of hexanediol, the yield of hexamethylenediamine and the content of by-products were determined. The target product was hexamethylenediamine, and the following by-products were included: cyclohexylideneimine, 6-amino-1-hexanol, pentylamine, pentanol, and dimers (N-(6-aminohexyl)-1,6-hexanediamine and N-(6-aminohexyl)cyclohexylideneimine). The results are shown in Table 1.

[0047] Example 2

[0048] Active Al2O3 was used as a catalyst carrier, and nickel nitrate and triphenylphosphine were impregnated on the carrier, and then the catalyst Ni / AlPO4-Al2O3 was formed by hydrogen reduction. x The loading amount of Ni was 10 wt%, and the amount of triphenylphosphine was 0.33 times the amount of substance of nickel nitrate, and the catalyst was obtained by hydrogen reduction at 550°C.

[0049] Example 3

[0050] Active Al2O3 was used as a catalyst carrier, and nickel nitrate and triphenylphosphine were impregnated on the carrier, and then the catalyst Ni / AlPO4-Al2O3 was formed by hydrogen reduction. The loading amount of Ni was 10 wt%, and the amount of triphenylphosphine was 0.33 times the amount of substance of nickel nitrate, and the catalyst was obtained by hydrogen reduction at 550°C.x Al2O3. The catalyst was used for the reductive amination of hexandiol and the activity and selectivity of the catalyst were determined. The reaction process and conditions were as shown in Example 1, and the reaction was carried out for 13.5 h. The results are shown in Table 1.

[0051] Example 4

[0052] Active Al2O3 was used as a catalyst carrier, and nickel nitrate and triphenylphosphine were impregnated onto the carrier, and then the catalyst was formed by hydrogen reduction. The loading of Ni was 10 wt%, and the amount of triphenylphosphine was 2 times the amount of substance of nickel nitrate, and the catalyst Ni / AlPO x Al2O3. The catalyst was used for the reductive amination of hexandiol and the activity and selectivity of the catalyst were determined. The reaction process and conditions were as shown in Example 1, and the reaction was carried out for 14 h. The results are shown in Table 1.

[0053] Example 5

[0054] Active Al2O3 was used as a catalyst carrier, and nickel nitrate and triphenylphosphine were impregnated onto the carrier, and then the catalyst was formed by hydrogen reduction. The loading of Ni was 10 wt%, and the amount of triphenylphosphine was 3 times the amount of substance of nickel nitrate, and the catalyst Ni / AlPO x Al2O3. The catalyst was used for the reductive amination of hexandiol and the activity and selectivity of the catalyst were determined. The reaction process and conditions were as shown in Example 1, and the reaction was carried out for 14 h. The results are shown in Table 1.

[0055] Example 6

[0056] Active Al2O3 was used as a catalyst carrier, and nickel nitrate and triphenylphosphine were impregnated onto the carrier, and then the catalyst was formed by hydrogen reduction. The loading of Ni was 10 wt%, and the amount of triphenylphosphine was 2 times the amount of substance of nickel nitrate, and the catalyst Ni / AlPO x Al2O3. The catalyst was used for the reductive amination of hexandiol and the activity and selectivity of the catalyst were determined. The reaction process and conditions were as shown in Example 1, and the reaction was carried out for 9 h at a temperature of 230°C. The results are shown in Table 1.

[0057] Example 7

[0058] Active Al2O3 was used as a catalyst carrier, and nickel nitrate and triphenylphosphine were impregnated onto the carrier, and then the catalyst was formed by hydrogen reduction. The loading of Ni was 10 wt%, and the amount of triphenylphosphine was 2 times the amount of substance of nickel nitrate, and the catalyst Ni / AlPO xAl2O3. The catalyst was used for the reductive amination of hexandiol and the activity and selectivity of the catalyst were determined. The reaction process and conditions were as shown in Example 1, the reaction temperature was 230°C, 11 MPa ammonia was pumped in, and the reaction was carried out for 9 h. The results are shown in Table 1.

[0059] Example 8

[0060] Active Al2O3 was used as a catalyst carrier, and nickel nitrate and triphenylphosphine were impregnated onto the carrier to form a catalyst after hydrogen reduction. The loading of Ni was 10 wt%, and the amount of triphenylphosphine was twice the amount of nickel nitrate by mass, and the catalyst Ni / AlPO4was obtained by calcination at 300°C in a nitrogen atmosphere for 2 h and reduction in hydrogen at 550°C for 2 h. x Al2O3. The catalyst was used for the reductive amination of hexandiol and the activity and selectivity of the catalyst were determined. The reaction process and conditions were as shown in Example 1, the reaction temperature was 230°C, 11 MPa ammonia was pumped in, and the reaction was carried out for 9 h. The results are shown in Table 1.

[0061] Example 9

[0062] Active Al2O3 was used as a catalyst carrier, and nickel nitrate and triphenylphosphine were impregnated onto the carrier to form a catalyst after hydrogen reduction. The loading of Ni was 10 wt%, and the amount of triphenylphosphine was twice the amount of nickel nitrate by mass, and the catalyst Ni / AlPO4was obtained by calcination at 300°C in a nitrogen atmosphere for 2 h and reduction in hydrogen at 550°C for 2 h. x Al2O3. The catalyst was used for the reductive amination of hexandiol and the activity and selectivity of the catalyst were determined. The reaction process and conditions were as shown in Example 1, the reaction temperature was 230°C, 11 MPa ammonia was pumped in, and the reaction was carried out for 9 h. The results are shown in Table 1.

[0063] Example 10

[0064] Active Al2O3 was used as a catalyst carrier, and nickel nitrate and triphenylphosphine were impregnated onto the carrier to form a catalyst after hydrogen reduction. The loading of Ni was 10 wt%, and the amount of triphenylphosphine was twice the amount of nickel nitrate by mass, and the catalyst Ni / AlPO4was obtained by calcination at 300°C in a nitrogen atmosphere for 2 h and reduction in hydrogen at 550°C for 2 h. x Al2O3. The catalyst was used for the reductive amination of hexandiol and the activity and selectivity of the catalyst were determined. The reaction process and conditions were as shown in Example 1, the reaction temperature was 230°C, 11 MPa ammonia was pumped in, and the reaction was carried out for 9 h. The results are shown in Table 1.

[0065] Comparative Example 1

[0066] Active Al2O3 was used as a catalyst carrier, and nickel nitrate was impregnated on the carrier, and then the catalyst was formed by hydrogen reduction. The loading amount of Ni was 10wt%, and the catalyst Ni / Al2O3 was obtained by hydrogen reduction at 550°C for 2h. The above catalyst was used for the reductive amination of hexanediol, and the activity and selectivity of the catalyst were determined. The reaction process and conditions were shown in Example 1, and the reaction was carried out for 12h. The results were shown in Table 1.

[0067] Figure 1 The catalyst Ni / AlPO4 was prepared by using AlPO4 as a catalyst carrier, and impregnating nickel nitrate on the carrier, and then the catalyst was formed by hydrogen reduction. The loading amount of Ni was 10wt%, and the catalyst Ni / AlPO4 was obtained by hydrogen reduction at 550°C for 2h. The above catalyst was used for the reductive amination of hexanediol, and the activity and selectivity of the catalyst were determined. The reaction process and conditions were shown in Example 1, and the reaction was carried out for 24h. The results were shown in Table 1. x The photoelectron spectrograms of the catalyst Ni / Al2O3, wherein (1) is the Al photoelectron spectrogram of Examples 1-5 and Comparative Example 1, and (2) is the P photoelectron spectrogram of Examples 1-5. The results of (1) show that the catalyst prepared in Examples 1-5 contains other aluminum ions with valence state of 0 x

[0068] Comparative Example 2

[0069] The catalyst Ni / AlPO4 was prepared by using AlPO4 as a catalyst carrier, and impregnating nickel nitrate on the carrier, and then the catalyst was formed by hydrogen reduction. The loading amount of Ni was 10wt%, and the catalyst Ni / AlPO4 was obtained by hydrogen reduction at 550°C for 2h. The above catalyst was used for the reductive amination of hexanediol, and the activity and selectivity of the catalyst were determined. The reaction process and conditions were shown in Example 1, and the reaction was carried out for 24h. The results were shown in Table 1.

[0070] Comparative Example 3

[0071] The catalyst Ni / Al2O3 was prepared by using active Al2O3 as a catalyst carrier, and impregnating nickel hypophosphite hexahydrate on the carrier in equal volume, and the loading amount of Ni was 10wt%. The catalyst was obtained by calcination at 300°C for 3h and hydrogen reduction at 550°C for 2h. The above catalyst was used for the reductive amination of hexanediol, and the activity and selectivity of the catalyst were determined. The reaction process and conditions were shown in Example 1, and the reaction was carried out for 12h. The results were shown in Table 1.

[0072] Table 1 Results of the reductive amination of hexanediol

[0073]

[0074] ​The above description of the embodiments is only used to help understand the method of the present application and its core idea. It should be noted that, for those skilled in the art, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A Ni-based catalyst for the reductive amination of hexanediamine from hexanediol, characterized in that, Depend on Composed of active ingredient Ni and carrier; The carrier is AlPO x Modified active Al2O3; Where 0 < x < 4; The AlPO x It is prepared by reacting organophosphorus compounds with active Al2O3; The preparation method of the Ni-based catalyst includes the following steps: A Ni-based catalyst for the reductive amination of hexanediamine by impregnating a nickel precursor and an organophosphorus compound onto the surface of an active Al2O3 catalyst and then reducing it with hydrogen was prepared. The molar ratio of the nickel precursor to the organophosphorus is 1:(0.33~3). The hydrogen reduction reaction is preceded by calcination. The calcination temperature is 200℃~600℃.

2. The Ni-based catalyst for the reductive amination of hexanediamine with hexanediol according to claim 1, characterized in that, The loading of the active ingredient Ni is 5 wt% to 15 wt%.

3. The Ni-based catalyst for the reductive amination of hexanediamine from hexanediol according to claim 1, characterized in that, The organophosphine is selected from one or more of triphenylphosphine, triphenylphosphine oxide, sodium triphenylphosphine sulfonate, tri-tert-butylphosphine, trimethylphosphine, tributylphosphine, trihexylphosphine, trioctylphosphine, trifuranylphosphine, trimethylmethylphosphine, triphenylmethylphosphine, and trifluorophenylphosphine.

4. A method for preparing a Ni-based catalyst for the reductive amination of hexanediamine according to any one of claims 1 to 3, characterized in that, Includes the following steps: A Ni-based catalyst for the reductive amination of hexanediamine by impregnating a nickel precursor and an organophosphorus compound onto the surface of an active Al2O3 catalyst and then reducing it with hydrogen was prepared. The molar ratio of the nickel precursor to the organophosphorus is 1:(0.33~3). The hydrogen reduction reaction is preceded by calcination. The calcination temperature is 200℃~600℃.

5. The preparation method according to claim 4, characterized in that, The nickel precursor is selected from nickel metal salts.

6. The preparation method according to claim 5, characterized in that, The nickel metal salt is selected from one or more of nickel nitrate hexahydrate, nickel chloride hexahydrate, and nickel sulfate hexahydrate.

7. The preparation method according to claim 4, characterized in that, The hydrogen gas flow rate for the hydrogen reduction reaction is 10 ~ 30 mL / min; The temperature of the hydrogen reduction reaction is 400℃~700℃.

8. A method for preparing hexamethylenediamine, characterized in that, The reduction amination reaction is carried out using the Ni-based catalyst for the preparation of hexanediamine by the reduction amination of hexanediamine according to any one of claims 1 to 3 or the Ni-based catalyst for the preparation of hexanediamine by the preparation method according to any one of claims 4 to 7 as a catalyst to prepare hexanediamine.

9. The preparation method according to claim 8, characterized in that, Ammonia is used for the reducing amination reaction; The pressure of the ammonia gas is 1~20 MPa; The temperature for the reductive amination reaction is 190 ℃ to 250 ℃.

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