Preparation method and application of catalyst for generating diethylenetriamine from iminodiacetonitrile

Abstract

The invention relates to a preparation method and application of a catalyst for producing diethylenetriamine from iminodiacetonitrile, and belongs to the technical field of fine chemical engineering. According to the catalyst, an Al2O3 carrier is modified through alkali metal and rare earth metal to obtain a modified M2O-ROx / Al2O3 carrier, and then a nickel-copper bimetallic active component is loaded on the modified M2O-ROx / Al2O3 carrier to obtain the Ni-Cu-M2O-ROx / Al2O3 catalyst. The catalyst is used in a process for generating diethylenetriamine from iminodiacetonitrile, and is a low-cost catalyst which is adaptive to a high-pressure fixed bed process and has high mechanical strength, high stability and high selectivity.

Description

Technical Field

[0001] This invention belongs to the field of fine chemical technology, specifically a method for preparing and applying a catalyst for the formation of diethylenetriamine from iminodiacetonitrile. Background Technology

[0002] Diethylenetriamine is an important fine chemical intermediate widely used in epoxy resin curing agents, pesticides, dyes, and water treatment agents. Traditional production processes mainly rely on the ammonolysis of ethanolamine, but this route suffers from high energy consumption, numerous byproducts, and low atom utilization. The catalytic hydrogenation of iminodiacetonitrile (IDAN) to produce DETA offers advantages such as high atom economy, inexpensive raw materials, and a green process, making it an important direction for future replacement of traditional processes.

[0003] For a long time, Group VIII noble metals (PGMs), represented by platinum (Pt), palladium (Pd), ruthenium (Ru), and rhodium (Rh), have been widely used as the core active components of various hydrogenation catalysts due to their excellent hydrogenation activity (especially at low temperatures), good selectivity (especially for the specific hydrogenation of unsaturated bonds), and certain resistance to carbon deposition. However, their prohibitively high cost, inherent susceptibility to poisoning and deactivation, resource scarcity, and environmental sustainability challenges have become bottlenecks restricting the large-scale, efficient, economical, and green application of related hydrogenation technologies.

[0004] For the hydrogenation of iminodiacetonitrile to diethylenetriamine, researchers have developed Raney-type catalysts, among which Raney cobalt and Raney nickel are the most commonly used. When Raney-type catalysts are used in this reaction, the selectivity of diethylenetriamine reaches 82%. However, the byproduct piperazine has high selectivity and short lifetime. Furthermore, Raney-type catalysts are not suitable for high-pressure fixed-bed reactors for continuous hydrogenation due to their low mechanical strength.

[0005] To adapt to high-pressure fixed-bed processes, the development of supported metal catalysts is necessary. Currently, the most commonly used non-precious metal supported catalysts are nickel and cobalt supported separately on supports. Ni / Al₂O₃ catalysts are prevalent in the market. These catalysts use a strongly acidic support to promote IDAN cyclization, thus increasing piperazine selectivity. However, this reaction is strongly exothermic, and the excessively high local temperatures at the active sites during the reaction process easily cause Ni to sinter and agglomerate, ultimately leading to catalyst deactivation. To address the support issue, patent CN107930698 A discloses a catalyst using a chromium metal-organic framework (MOF) as a support, which is activated with an organic base before being loaded with nickel and cobalt. However, chromium MOFs have low mechanical strength as supports and are not suitable for the high-pressure fixed-bed reactor process of hydrogenating iminodiacetonitrile to diethylenetriamine.

[0006] Current problems with the iminodiacetonitrile reaction process and catalysts: 1. The IDAN molecule contains two nitrile groups (-CN) and one imino group (-NH-). The hydrogenation process is prone to over-hydrogenation (generating byproducts such as ethylenediamine and aminoethyl) or cyclization reaction (generating piperazine impurities). Therefore, the catalyst should be selected to inhibit the occurrence of over-hydrogenation reaction.

[0007] 2. Traditional catalysts are prone to pulverization or carbon buildup and blockage under high pressure (>8MPa).

[0008] 3. The strong exothermic reaction of hydrogenation of nitrile groups leads to local overheating, which accelerates the sintering of active components.

[0009] Therefore, there is an urgent need to develop a dedicated catalyst with low cost, high stability, high selectivity, and high mechanical strength to break through the industrialization bottleneck of IDAN-to-DETA production. Summary of the Invention

[0010] The purpose of this invention is to address the problems existing in current catalysts for the hydrogenation of iminodiacetonitrile to diethylenetriamine, and to provide a low-cost catalyst with high mechanical strength, high stability, and high selectivity suitable for high-pressure fixed-bed processes. When used in the production process of hydrogenating iminodiacetonitrile to diethylenetriamine, this catalyst can effectively suppress side reactions and significantly improve the yield of the target product.

[0011] To achieve the above-mentioned objectives, the specific technical solution of the present invention is as follows: A supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, with the chemical composition Ni-Cu-M2O-RO. x / Al2O3, where M is a modified alkali metal and R is a rare earth element; the catalyst is first modified by modifying the Al2O3 support with alkali metals and rare earth metals to obtain modified M2O-RO. x / Al2O3, then modified M2O-RO x Ni-Cu-M2O-RO is obtained by loading a nickel-copper bimetallic active component onto Al2O3. x / Al2O3 catalyst; This catalyst is a supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine.

[0012] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the total metal loading is 10-25 wt% of the support mass, specifically 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 24 wt%, 25 wt%, etc.

[0013] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the alkali metal is at least one selected from Li, Na, K, Rb, Cs, and Fr; the loading of the alkali metal is 0.1~2 wt% (calculated as M2O), specifically 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%, 1.0 wt%, 1.2 wt%, 1.4 wt%, 1.6 wt%, 1.8 wt%, 2.0 wt%, etc.

[0014] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the rare earth metal is at least one selected from La, Ce, Pr, Nd, and Eu; the loading of the rare earth metal is 1-5 wt% (based on RO). x (Calculated), specifically, it can be 1wt%, x wt%, 2wt%, 2.5wt%, 3 wt%, 3.5wt%, 4 wt%, 4.5wt%, 5wt%, etc.

[0015] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the molar ratio of nickel to copper is 5:1 to 10:1, specifically 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc.

[0016] As a preferred embodiment of this application, the method for preparing a supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine described above includes the following steps: (a) Rare earth metals are synthesized into nanosols and then loaded onto an alumina support to obtain RO x / Al2O3 support; (b) An alkali metal salt solution is impregnated onto the support prepared in step (a) by an impregnation method to obtain alkali metal and rare earth metal modified M2O-RO. x / Al2O3 support, which is dried and calcined for later use; (c) Prepare a nickel-copper metal salt solution as an impregnation solution, impregnate the carrier prepared in step (b), and obtain Ni-Cu-M2O-RO after drying, calcination, and reduction. x / Al2O3 catalyst.

[0017] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the metal synthesis nanosol method employs a hydrothermal synthesis method. The steps include dissolving at least one of a rare earth precursor salt and a structural stabilizer and a homogeneous precipitant in water (i.e., rare earth precursor salt and structural stabilizer; or rare earth precursor salt and homogeneous precipitant; or rare earth precursor salt and both structural stabilizer and homogeneous precipitant). After thorough mixing, a monodisperse rare earth oxide nanosol is synthesized through a hydrothermal reaction. The hydrothermal reaction temperature is 60~150℃ (specifically, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, etc.), and the time is 2~48h (specifically, 2h, 8h, 14h, 20h, 26h, 32h, 38h, 44h, 48h, etc.).

[0018] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the rare earth precursor salt is any one or a mixture of nitrates or acetates of Ce, La, Pr, Nd, and Eu.

[0019] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the structural stabilizer is any one or a mixture of polyethylene glycol (PEG-400, PEG-600, PEG-1200), polyvinylpyrrolidone (PVP), polyvinyl alcohol, and citric acid.

[0020] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the homogeneous precipitant is any one or a mixture of urea, hexamethylenetetramine, and dimethyl oxalate.

[0021] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the molar ratio of the rare earth metal, structural stabilizer, and homogeneous precipitant is 1:0 to 1.5:0 to 10, specifically 1:0:1, 1:1:0, 1:1:1, 1:0.5:0.5, 1:0.5:1, 1:0.5:2, 1:0.5:3, 1:0.5:4, 1:0.5:5, 1:0.5:6, 1:0.5:7, 1:0.5:8, 1:0.5:9, 1:0.5:10, 1:1:3, 1:1:4, etc.; more preferably, it is 1:0.1 to 1.5:1 to 10.

[0022] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the alkali metal salt is any one or a mixture of nitrates, acetates, and carbonates of Li, Na, K, Rb, Cs, and Fr.

[0023] In a preferred embodiment of this application, in the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the nickel / copper metal salt solution is selected from any one or a mixture of nitrate, acetate, carbonate, hydrochloride, and sulfate solutions.

[0024] In a preferred embodiment of this application, in step (b) of the method for preparing a supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the drying temperature is 60-120℃ (specifically, it can be 60℃, 70℃, 80℃, 85℃, 90℃, 95℃, 100℃, 115℃, 120℃, etc.); the calcination temperature is 300-550℃ (specifically, it can be 500℃, 510℃, 520℃, 530℃, 540℃, 550℃, etc.); and the calcination time is 2-10h (specifically, it can be 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, etc.).

[0025] In a preferred embodiment of this application, in step (c) of the method for preparing a supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, the drying temperature is 80-120℃ (specifically, 80℃, 85℃, 90℃, 100℃, 105℃, 110℃, 115℃, 120℃, etc.); the calcination temperature is 300-550℃ (specifically, 500℃, 510℃, 520℃, 530℃, 540℃, 550℃, etc.), and the time is 2-10h (specifically, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, etc.); the reducing atmosphere is a hydrogen / argon mixture, the reducing temperature is 300-550℃ (specifically, 550℃, 560℃, 570℃, 580℃, 590℃, 600℃, etc.), and the time is 2-6 hours. h (specifically, it can be 2h, 3h, 4h, 5h, 6h, etc.).

[0026] Another objective of this application is to protect the application of the above-described supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine in the reaction of iminodiacetonitrile to diethylenetriamine.

[0027] As a preferred embodiment of this application, in the described application, Ni-Cu-M2O-RO is used. x The Al2O3 catalyst is tableted and then placed in a high-pressure fixed-bed reactor to participate in the reaction.

[0028] In a preferred embodiment of this application, the reaction temperature is 60-200℃, the pressure is 5.0-20MPa, and the LHSV liquid hourly space velocity is 0.2-4 h⁻¹. -1 .

[0029] In a preferred embodiment of this application, in the described application, iminodiacetonitrile is dissolved in a solvent to form a solution, wherein the solvent is selected from one or more of methanol, ethanol, propanol, ethylene glycol, pyridine, piperidine, tetrahydrofuran, oxacyclohexane, morpholine, 1,4-dioxane, triethylamine, diethylamine, phenylenediamine, aniline, cyclohexylamine, ethylenediamine, N,N-dimethylformamide, N,N-dimethylacetamide, propylene glycol methyl ether, propylene glycol dimethyl ether, ethylene glycol monobutyl ether, and dipropylene glycol methyl ether, more preferably N,N-dimethylformamide.

[0030] In a preferred embodiment of this application, in the application described, iminodiacetonitrile is dissolved in a solvent to form a solution, wherein the mass fraction of iminodiacetonitrile is 1% to 30%, specifically 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, etc., more preferably 5% to 20%.

[0031] Compared with the prior art, the positive effects of the present invention are reflected in: 1. This invention utilizes a continuous reaction process, solving the problem that current batch reactions using Raney catalysts in the hydrogenation of iminodiacetonitrile are difficult to achieve large-scale production. The continuous reaction process enables large-scale production, improves production efficiency, provides high product stability, and significantly reduces energy consumption.

[0032] 2. The main carrier used in this invention is alumina, one of the most widely used carriers currently available. Alumina possesses a certain mechanical strength after molding, making it suitable for high-pressure fixed-bed reactions. Building upon this, this invention uses alkali metals to acidify the alumina carrier. The addition of alkali metals reduces the surface acidity of the carrier, which prevents polymerization and cyclization reactions at acidic sites during hydrogenation, significantly improving the yield of the target product.

[0033] 3. The present invention further modifies the alumina support by using rare earth metals. The rare earth metals are highly dispersed on the alumina support in the form of nanoparticles, forming a perovskite phase with the alumina support. This phase has a stabilizing effect on the loaded nickel-copper metal, ensuring the high dispersion of the loaded nickel-copper metal on the support, and also preventing metal sintering due to local overheating of active sites during the reaction process.

[0034] 4. This invention also employs a nickel-copper bimetallic active component. The addition of copper metal weakens the adsorption of secondary amines and blocks the condensation path. Excessive adsorption of secondary amines is the root cause of the formation of piperazine byproducts. The addition of copper, by adjusting the electronic properties of nickel, weakens the adsorption strength of the reaction intermediate secondary amine and inhibits the occurrence of side reactions. Attached Figure Description

[0035] Figure 1 This is a TEM image of catalyst A1 prepared in Example 1. Detailed Implementation

[0036] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0037] Any feature disclosed in this specification (including the claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0038] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0039] Unless otherwise specified, the process methods used in the embodiments are conventional methods; unless otherwise specified, the materials used are commercially available.

[0040] Example 1 Example 1: Preparation of Ni-Cu-K2O-CeO2 / Al2O3 a) Weigh 1.53g of Ce(NO3)3·6H2O and 0.4g of PEG-400, dissolve them in 40 mL of deionized water, mix thoroughly, and then hydrothermally treat at 120℃ for 6 h to obtain highly dispersed cerium oxide nanosol. Weigh 20g of Al2O3 (specific surface area 280 m²) 2 The support (0.8 mL / g pore volume) was added to cerium oxide nanosol and stirred for 6 h, followed by filtration and washing to obtain the CeO2 / Al2O3 support.

[0041] b) Weigh 0.18g of potassium nitrate and dissolve it in 18ml of deionized water, then impregnate the prepared CeO2 / Al2O3 support. The specific impregnation process is as follows: add the potassium nitrate impregnation solution dropwise to the CeO2 / Al2O3 support to disperse it, sonicate for 1 h, dry it overnight at 80℃, and then calcine it at 500℃ for 4 h to obtain K2O-CeO2 / Al2O3 as a modified support for later use.

[0042] c) Weigh 10.45 g Ni(NO3)2·6H2O and 1.45 g Cu(NO3)2·3H2O respectively and dissolve them in 16 ml of deionized water to obtain a metal salt impregnation solution. Impregnate the metal salt impregnation solution onto a K2O-CeO2 / Al2O3 modified support, sonicate for 1.5 h, dry at 100 °C overnight, calcine at 500 °C for 4 h, and then reduce in a hydrogen atmosphere at 550 °C for 4 h to obtain the Ni-Cu-K2O-CeO2 / Al2O3 catalyst, in which the total metal loading is 13 wt%, the Ni:Cu molar ratio is 6:1, the CeO2 loading is 3 wt%, and the K2O loading is 0.4 wt%, denoted as catalyst A1.

[0043] The catalyst A1 was compressed into tablets, sieved through a 40-80 mesh screen, and 5g of the catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 120℃, pressure 6.0 MPa, H2 flow rate 80 mL / min, and liquid hourly space velocity (LHSV) 0.4 h⁻¹. - ¹.

[0044] Transmission electron microscopy was performed on the supported nickel-copper bimetallic catalyst prepared in Example 1, as detailed in the figure. Figure 1 , Figure 1 Transmission electron microscopy (TEM) images of the supported nickel-copper bimetallic catalyst A1 are shown. The images reveal that the metal elements are uniformly dispersed on the support, indicating that the catalyst prepared using this method possesses good metal particle size and dispersion, thus ensuring excellent catalytic performance.

[0045] Example 2 Ni-Cu-Na2O-LaO 1.5 Preparation of Al2O3 a) Weigh 3.24 g of La(NO3)3·6H2O, 0.15 g of citric acid, and 0.45 g of urea, respectively, and dissolve them in 40 mL of deionized water. After thorough mixing, the mixture is hydrothermally heated at 80 °C for 24 h to obtain highly dispersed lanthanum oxide nanosol. Weigh 20 g of Al2O3 (specific surface area 280 m² / g). 2 Lanthanum oxide nanosol (with a pore volume of 0.8 mL / g) was added to the carrier and stirred for 6 hours, followed by filtration and washing to obtain LaO. 1.5 / Al2O3 support.

[0046] b) Weigh 0.51g of sodium carbonate and dissolve it in 20ml of deionized water, then immerse it in LaO2 solution. 1.5 / Al2O3 support. The impregnation process is as follows: sodium carbonate impregnation solution is added dropwise to LaO2O3 support. 1.5The Na₂O-LaO₃ was dispersed in an Al₂O₃ support, sonicated for 1 hour, dried overnight at 80°C, and then calcined at 500°C for 4 hours to obtain Na₂O-LaO₃. 1.5 Al2O3 was used as a modification carrier.

[0047] c) Weigh 16.0 g Ni(NO3)2·6H2O and 1.45 g Cu(NO3)2·3H2O respectively, dissolve them in 16 ml of deionized water to obtain a metal salt impregnation solution, and impregnate the above impregnation solution in Na2O-LaO. 1.5 On an Al2O3 modified support, the mixture was sonicated for 1.5 h, dried overnight at 100 °C, calcined at 500 °C for 4 h, and then reduced in a hydrogen atmosphere at 550 °C for 4 h to obtain Ni-Cu-Na2O-LaO. 1.5 / Al2O3 catalyst, wherein the total metal loading is 18 wt%, the Ni:Cu molar ratio is 9:1, and LaO 1.5 The catalyst has a loading of 6 wt% and a Na2O loading of 1.5 wt%, and is designated as catalyst A2.

[0048] The catalyst A2 was compressed into tablets, sieved to 40-80 mesh, and 5g of the catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 110℃, pressure 8.0 MPa, H2 flow rate 100 mL / min, and liquid hourly space velocity (LHSV) 0.45 h⁻¹. - ¹.

[0049] Example 3 Ni-Cu-Na2O-NdO 1.5 Preparation of Al2O3 a) Weigh 1.04 g of Nd(NO3)3·6H2O and 0.5 g of PEG-400, dissolve them in 40 mL of deionized water, mix thoroughly, and then hydrothermally heat at 120℃ for 6 h to obtain highly dispersed neodymium oxide nanosol. Weigh 20 g of Al2O3 (specific surface area 280 m²) 2 The support (0.8 mL / g pore volume) was added to neodymium oxide nanosol and stirred for 6 h, followed by filtration and washing to obtain NdO. 1.5 / Al2O3 support.

[0050] b) Weigh 0.1g of sodium carbonate and dissolve it in 20ml of deionized water, then immerse it in the above-mentioned NdO. 1.5 / Al2O3 support. The impregnation process is as follows: sodium carbonate impregnation solution is added dropwise to NdO. 1.5 The Na₂O-NdO was dispersed in an Al₂O₃ support, sonicated for 1 h, dried overnight at 80 °C, and then calcined at 500 °C for 4 h to obtain Na₂O-NdO.1.5 Al2O3 was used as a modification carrier.

[0051] c) Weigh 12.15 g of Ni(NO3)2·6H2O and 1.9 g of Cu(NO3)2·3H2O respectively, dissolve them in 16 ml of deionized water to obtain a metal salt impregnation solution, and impregnate the above impregnation solution in Na2O-NdO. 1.5 On an Al2O3 support, the mixture was sonicated for 1.5 h, dried overnight at 100 °C, calcined at 500 °C for 4 h, and then reduced in a hydrogen atmosphere at 550 °C for 4 h to obtain Ni-Cu-Na2O-NdO. 1.5 / Al2O3 catalyst, wherein the total metal loading is 15 wt%, the Ni:Cu molar ratio is 5:1, and NdO 1.5 The catalyst has a loading of 2 wt% and a Na2O loading of 0.3 wt%, and is designated as catalyst A3.

[0052] The catalyst A3 was compressed into tablets, sieved to 40-80 mesh, and 5g of the catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 100℃, pressure 10.0 MPa, H2 flow rate 100 mL / min, and liquid hourly space velocity (LHSV) 0.45 h⁻¹. - ¹.

[0053] Example 4 Ni-Cu-Li2O-PrO 1.5 Preparation of Al2O3 a) Weigh 1.31g Pr(NO3)3·6H2O and 0.45g PEG-400 respectively, dissolve them in 40 mL of deionized water, mix thoroughly, and then hydrothermally heat at 100℃ for 10 h to obtain highly dispersed praseodymium oxide nanosol. Weigh 20g Al2O3 (specific surface area 280 m²) 2 The carrier (0.8 mL / g, pore volume 0.8 mL / g) was added to the above nanosol and stirred for 8 h, followed by filtration and washing to obtain PrO. 1.5 / Al2O3 support.

[0054] b) Weigh 0.14 g of lithium nitrate and dissolve it in 20 ml of deionized water, then impregnate the carrier as described above. The impregnation process is as follows: add the lithium nitrate impregnation solution dropwise to PrO2. 1.5 The Li₂O-PrO₃ was dispersed in an Al₂O₃ support, sonicated for 1 h, dried overnight at 80 °C, and then calcined at 500 °C for 4 h to obtain Li₂O-PrO₃. 1.5 Al2O3 was used as a modification carrier.

[0055] c) Weigh 8.75 g of Ni(NO3)2·6H2O and 0.7 g of Cu(NO3)2·3H2O respectively, dissolve them in 16 ml of deionized water to obtain a metal salt impregnation solution, and impregnate the above impregnation solution in 0.15 wt% Li2O-2.5 wt% PrO 1.5 On an Al2O3 support, the mixture was sonicated for 1.5 h, dried overnight at 100 °C, calcined at 500 °C for 4 h, and then reduced in a hydrogen atmosphere at 550 °C for 4 h to obtain Ni-Cu-Li2O-PrO. 1.5 / Al2O3 catalyst, wherein the total metal loading is 10 wt%, the Ni:Cu molar ratio is 10:1, and PrO 1.5 The catalyst has a loading of 2.5 wt% and a Li2O loading of 0.15 wt%, and is designated as catalyst A4.

[0056] The above-mentioned catalyst A4 was compressed into tablets, sieved to 40-80 mesh, and 5g of catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 120℃, pressure 8.0 MPa, H2 flow rate 80 mL / min, and liquid hourly space velocity (LHSV) 0.4 h. - ¹.

[0057] Example 5 Ni-Cu-Li2O-CeO2&LaO 1.5 Preparation of Al2O3 a) Weigh 0.66 g of Ce(NO3)3·6H2O, 0.66 g of La(NO3)3·6H2O, and 0.6 g of PEG-400, respectively, and dissolve them in 40 mL of deionized water. After thorough mixing, hydrothermally heat at 110 °C for 10 h to obtain highly dispersed cerium oxide and lanthanum oxide nanosols. Weigh 20 g of Al2O3 (specific surface area 280 m²). 2 The carrier (0.8 mL / g, pore volume 0.8 mL / g) was added to the above nanosol and stirred for 8 h, followed by filtration and washing to obtain CeO2 & LaO2. 1.5 / Al2O3 support.

[0058] b) Weigh 0.14g of potassium carbonate and dissolve it in 20ml of deionized water, then impregnate the above-mentioned carrier. The impregnation process is as follows: add the potassium carbonate impregnation solution dropwise to CeO2 & LaO2. 1.5 The K2O-CeO2 & LaO3 mixture was dispersed in an Al2O3 support, sonicated for 1 hour, dried overnight at 80°C, and then calcined at 500°C for 4 hours to obtain K2O-CeO2 & LaO3. 1.5 Al2O3 was used as a modification carrier.

[0059] c) Weigh out 13.95 g Ni(NO3)2·6H2O and 1.45 g Cu(NO3)2·3H2O respectively, dissolve them in 16 ml of deionized water to obtain a metal salt impregnation solution, and impregnate the above impregnation solution in K2O-CeO2 & LaO 1.5 On an Al2O3 support, the mixture was sonicated for 1.5 h, dried overnight at 100 °C, calcined at 500 °C for 4 h, and then reduced in a hydrogen atmosphere at 550 °C for 4 h to obtain Ni-Cu-K2O-CeO2&LaO2. 1.5 / Al2O3 catalyst, with a total metal loading of 16 wt%, a Ni:Cu molar ratio of 8:1, and CeO2 & LaO 1.5 The total loading is 2.5 wt%, the Ce:La molar ratio is 1:1, and the K2O loading is 0.5 wt%, denoted as catalyst A5.

[0060] The above-mentioned catalyst A5 was compressed into tablets, sieved to 40-80 mesh, and 5g of catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 110℃, pressure 8.0 MPa, H2 flow rate 100 mL / min, and liquid hourly space velocity (LHSV) 0.4 h. - ¹.

[0061] Comparative Example 1: Preparation of Ni-Cu / Al2O3 a) Weigh out 10.45 g Ni(NO3)2·6H2O and 1.45 g Cu(NO3)2·3H2O respectively, dissolve them in 16 ml of deionized water to obtain a metal salt impregnation solution, and impregnate the above impregnation solution in 20 g Al2O3 (specific surface area 280 m²). 2 On a support with a pore volume of 0.8 mL / g, the catalyst was sonicated for 0.5 h, dried overnight at 100 °C, calcined at 500 °C for 4 h, and then reduced in a hydrogen atmosphere at 550 °C for 4 h to obtain the Ni-Cu-Al2O3 catalyst with a total metal loading of 13 wt% and a Ni:Cu molar ratio of 6:1, denoted as catalyst B1.

[0062] The catalyst B1 was compressed into tablets, sieved to 40-80 mesh, and 5g of the catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylacetamide solution of iminodiacetonitrile. The reaction conditions were: temperature 120℃, pressure 6.0 MPa, H2 flow rate 80 mL / min, and liquid hourly space velocity (LHSV) 0.4 h. - ¹.

[0063] Comparative Example 2: Preparation of Ni-Cu-CeO2 / Al2O3 a) Weigh 1.53g Ce(NO3)3·6H2O and 0.4g PEG-400 respectively, dissolve them in 40 mL of deionized water, mix thoroughly, and then hydrothermally heat at 120℃ for 6 h to obtain highly dispersed cerium oxide nanosol. Weigh 20g Al2O3 (specific surface area 280 m²) 2 The CeO2 / Al2O3 support (with a pore volume of 0.8 mL / g) was added to the nanosol and stirred for 6 hours, followed by filtration and washing to obtain the CeO2 / Al2O3 support.

[0064] b) Weigh 10.45 g Ni(NO3)2·6H2O and 1.45 g Cu(NO3)2·3H2O respectively and dissolve them in 16 ml of deionized water to obtain a metal salt impregnation solution. Impregnate the above impregnation solution onto a CeO2 / Al2O3 support, sonicate for 1.5 h, dry at 100 °C overnight, calcine at 500 °C for 4 h, and then reduce in a hydrogen atmosphere at 550 °C for 4 h to obtain a Ni-Cu-CeO2 / Al2O3 catalyst with a total metal loading of 13 wt% and a Ni:Cu molar ratio of 6:1, denoted as catalyst B2.

[0065] The catalyst B2 was compressed into tablets, sieved to 40-80 mesh, and 5g of the catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 120℃, pressure 6.0 MPa, H2 flow rate 80 mL / min, and liquid hourly space velocity (LHSV) 0.4 h. - ¹.

[0066] Comparative Example 3: Preparation of Ni-Cu-K2O / Al2O3 a) Weigh 0.18g of potassium nitrate and dissolve it in 20ml of deionized water, then impregnate it onto 20g of Al2O3 support. The impregnation process is as follows: add the potassium nitrate impregnation solution dropwise to the Al2O3 support to disperse it, sonicate for 1 h, dry at 80℃ overnight, and then calcine at 500℃ for 4 h to obtain K2O / Al2O3 for later use.

[0067] b) Weigh 10.45 g Ni(NO3)2·6H2O and 1.45 g Cu(NO3)2·3H2O respectively and dissolve them in 16 ml of deionized water to obtain a metal salt impregnation solution. Impregnate the above impregnation solution on a K2O / Al2O3 support, sonicate for 1.5 h, dry at 100 °C overnight, calcine at 500 °C for 4 h, and then reduce in a hydrogen atmosphere at 550 °C for 4 h to obtain the Ni-Cu-K2O- / Al2O3 catalyst with a total metal loading of 13 wt% and a Ni:Cu molar ratio of 6:1, denoted as catalyst B3.

[0068] The catalyst B3 was compressed into tablets, sieved to 40-80 mesh, and 5g of catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 120℃, pressure 6.0 MPa, H2 flow rate 80 mL / min, and liquid hourly space velocity (LHSV) 0.4 h. - ¹.

[0069] Comparative Example 4: Preparation of Ni-K2O-CeO2 / Al2O3 a) Weigh 1.53g of Ce(NO3)3·6H2O and 0.4g of PEG-400, dissolve them in 40 mL of deionized water, mix thoroughly, and then hydrothermally treat at 120℃ for 6 h to obtain highly dispersed cerium oxide nanosol. Weigh 20g of Al2O3 (specific surface area 280 m²) 2 The support (0.8 mL / g pore volume) was added to cerium oxide nanosol and stirred for 6 h, followed by filtration and washing to obtain the CeO2 / Al2O3 support.

[0070] b) Weigh 0.18g of potassium nitrate and dissolve it in 20ml of deionized water, then impregnate it onto the prepared CeO2 / Al2O3 support. The specific impregnation process is as follows: add the potassium nitrate impregnation solution dropwise to the CeO2 / Al2O3 support to disperse it, sonicate for 1 hour, dry it overnight at 80℃, and then calcine it at 500℃ for 4 hours to obtain K2O-CeO2 / Al2O3 for later use.

[0071] c) Weigh 10.45 g Ni(NO3)2·6H2O and dissolve it in 16 ml of deionized water to obtain a metal salt impregnation solution. Impregnate the metal salt impregnation solution onto a K2O-CeO2 / Al2O3 support, sonicate for 1.5 h, dry overnight at 100 °C, calcine at 500 °C for 4 h, and then reduce in a hydrogen atmosphere at 550 °C for 4 h to obtain the Ni-K2O-CeO2 / Al2O3 catalyst with a total metal loading of 10.6 wt%, denoted as catalyst B4.

[0072] The catalyst B4 was compressed into tablets, sieved through a 40-80 mesh screen, and 5g of the catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 120℃, pressure 6.0 MPa, H2 flow rate 80 mL / min, and liquid hourly space velocity (LHSV) 0.4 h⁻¹. - ¹.

[0073] Comparative Example 5: Preparation of Cu-K2O-CeO2 / Al2O3 a) Weigh 1.53g of Ce(NO3)3·6H2O and 0.4g of PEG-400, dissolve them in 40 mL of deionized water, mix thoroughly, and then hydrothermally treat at 120℃ for 6 h to obtain highly dispersed cerium oxide nanosol. Weigh 20g of Al2O3 (specific surface area 280 m²) 2 The support (0.8 mL / g pore volume) was added to cerium oxide nanosol and stirred for 6 h, followed by filtration and washing to obtain the CeO2 / Al2O3 support.

[0074] b) Weigh 0.18g of potassium nitrate and dissolve it in 20ml of deionized water, then impregnate it onto the prepared CeO2 / Al2O3 support. The specific impregnation process is as follows: add the potassium nitrate impregnation solution dropwise to the CeO2 / Al2O3 support to disperse it, sonicate for 1 hour, dry it overnight at 80℃, and then calcine it at 500℃ for 4 hours to obtain K2O-CeO2 / Al2O3 for later use.

[0075] c) Weigh 1.45 g Cu(NO3)2·3H2O and dissolve it in 16 ml of deionized water to obtain a metal salt impregnation solution. Impregnate the metal salt impregnation solution onto a K2O-CeO2 / Al2O3 support, sonicate for 1.5 h, dry at 100 °C overnight, calcine at 500 °C for 4 h, and then reduce in a hydrogen atmosphere at 550 °C for 4 h to obtain the Cu-K2O-CeO2 / Al2O3 catalyst with a total metal loading of 2 wt%, denoted as catalyst B5.

[0076] The catalyst B5 was compressed into tablets, sieved through a 40-80 mesh screen, and 5g of the catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 120℃, pressure 6.0 MPa, H2 flow rate 80 mL / min, and liquid hourly space velocity (LHSV) 0.4 h. - ¹.

[0077] Comparative Example 6: Preparation of Cu-K2O-CeO2 / Al2O3 a) Weigh 1.53g of Ce(NO3)3·6H2O and 0.4g of PEG-400, dissolve them in 40 mL of deionized water, mix thoroughly, and then hydrothermally treat at 120℃ for 6 h to obtain highly dispersed cerium oxide nanosol. Weigh 20g of Al2O3 (specific surface area 280 m²) 2 The support (0.8 mL / g pore volume) was added to cerium oxide nanosol and stirred for 6 h, followed by filtration and washing to obtain the CeO2 / Al2O3 support.

[0078] b) Weigh 0.18g of potassium nitrate and dissolve it in 20ml of deionized water, then impregnate it onto the prepared CeO2 / Al2O3 support. The specific impregnation process is as follows: add the potassium nitrate impregnation solution dropwise to the CeO2 / Al2O3 support to disperse it, sonicate for 1 hour, dry it overnight at 80℃, and then calcine it at 500℃ for 4 hours to obtain K2O-CeO2 / Al2O3 for later use.

[0079] c) Weigh 8.02 g Cu(NO3)2·3H2O and dissolve it in 16 ml of deionized water to obtain a metal salt impregnation solution. Impregnate the metal salt impregnation solution onto a K2O-CeO2 / Al2O3 support, sonicate for 1.5 h, dry overnight at 100 °C, calcine at 500 °C for 4 h, and then reduce in a hydrogen atmosphere at 550 °C for 4 h to obtain the Ni-K2O-CeO2 / Al2O3 catalyst with a total metal loading of 10.6 wt%, denoted as catalyst B6.

[0080] The catalyst B6 was compressed into tablets, sieved through a 40-80 mesh screen, and 5g of the catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 120℃, pressure 6.0 MPa, H2 flow rate 80 mL / min, and liquid hourly space velocity (LHSV) 0.4 h⁻¹. - ¹.

[0081] Comparative Example 7: Preparation of Ni-Cu-K2O-CeO2 / Al2O3 a) Weigh 1.53g Ce(NO3)3·6H2O and 0.4g PEG-400 respectively, dissolve them in 40 mL of deionized water, mix thoroughly, and then hydrothermally heat at 120℃ for 6 h to obtain highly dispersed cerium oxide nanosol. Weigh 20g Al2O3 (specific surface area 280 m²) 2 The CeO2 / Al2O3 support (with a pore volume of 0.8 mL / g) was added to the nanosol and stirred for 6 hours, followed by filtration and washing to obtain the CeO2 / Al2O3 support.

[0082] b) Weigh 0.18g of potassium nitrate and dissolve it in 20ml of deionized water, then impregnate the above-mentioned carrier. The impregnation process is as follows: add the potassium nitrate impregnation solution dropwise to the CeO2 / Al2O3 carrier to disperse it, sonicate for 1 hour, dry at 80℃ overnight, and then calcine at 500℃ for 4 hours to obtain K2O-CeO2 / Al2O3 for later use.

[0083] c) Weigh 12.21 g Ni(NO3)2·6H2O and 0.68 g Cu(NO3)2·3H2O respectively and dissolve them in 16 ml of deionized water to obtain a metal salt impregnation solution. Impregnate the above impregnation solution onto a K2O-CeO2 / Al2O3 support, sonicate for 1.5 h, dry at 100 °C overnight, calcine at 500 °C for 4 h, and then reduce in a hydrogen atmosphere at 550 °C for 4 h to obtain a Ni-Cu-K2O-CeO2 / Al2O3 catalyst with a total metal loading of 13 wt% and a Ni:Cu molar ratio of 15:1, denoted as catalyst B7.

[0084] The catalyst B7 was compressed into tablets, sieved to 40-80 mesh, and 5g of catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 120℃, pressure 6.0 MPa, H2 flow rate 80 mL / min, and liquid hourly space velocity (LHSV) 0.4 h. - ¹.

[0085] Preparation of Comparative Example 8: Ni-Cu-K2O-CeO2 / Al2O3 a) Weigh 1.53g Ce(NO3)3·6H2O and 0.4g PEG-400 respectively, dissolve them in 40 mL of deionized water, mix thoroughly, and then hydrothermally heat at 120℃ for 6 h to obtain highly dispersed cerium oxide nanosol. Weigh 20g Al2O3 (specific surface area 280 m²) 2 The CeO2 / Al2O3 support (with a pore volume of 0.8 mL / g) was added to the nanosol and stirred for 6 hours, followed by filtration and washing to obtain the CeO2 / Al2O3 support.

[0086] b) Weigh 0.18g of potassium nitrate and dissolve it in 20ml of deionized water, then impregnate the above-mentioned carrier. The impregnation process is as follows: add the potassium nitrate impregnation solution dropwise to the CeO2 / Al2O3 carrier to disperse it, sonicate for 1 hour, dry at 80℃ overnight, and then calcine at 500℃ for 4 hours to obtain K2O-CeO2 / Al2O3 for later use.

[0087] c) Weigh 1.98 g Ni(NO3)2·6H2O and 8.2 g Cu(NO3)2·3H2O respectively and dissolve them in 16 ml of deionized water to obtain a metal salt impregnation solution. Impregnate the above impregnation solution onto a K2O-CeO2 / Al2O3 support, sonicate for 1.5 h, dry at 100 °C overnight, calcine at 500 °C for 4 h, and then reduce in a hydrogen atmosphere at 550 °C for 4 h to obtain the Ni-Cu-K2O-CeO2 / Al2O3 catalyst with a total metal loading of 13 wt% and a Ni:Cu molar ratio of 1:5, denoted as catalyst B8.

[0088] The above-mentioned catalyst B8 was compressed into tablets, sieved to 40-80 mesh, and 5g of catalyst was placed in a 316L reaction tube for reaction. The reaction solution was a 15wt% N,N-dimethylformamide solution of iminodiacetonitrile. The reaction conditions were: temperature 120℃, pressure 6.0 MPa, H2 flow rate 80 mL / min, and liquid hourly space velocity (LHSV) 0.4 h. - ¹.

[0089] application The supported nickel-copper bimetallic catalysts A1-A5 prepared in Examples 1-5 and the metal catalysts B1-B8 prepared in Comparative Examples 1-8 were used for the reaction of iminodiacetonitrile to generate diethylenetriamine. The evaluation results after the reaction are recorded in Table 1.

[0090] Table 1 Results of the reaction from iminodiacetonitrile to diethylenetriamine

[0091] As shown in Table 1, the supported nickel-copper bimetallic catalysts A1 to A5 prepared in this invention exhibit high initial iminodiacetonitrile conversion, high initial diethylenetriamine selectivity, and high yield when used in the reaction of iminodiacetonitrile to diethylenetriamine.

[0092] Compared with Example 1, Comparative Example 1 is an unmodified Al2O3 support loaded with nickel-copper bimetal. The catalyst obtained from it has a lower conversion rate and selectivity in the reaction of iminodiacetonitrile to diethylenetriamine. This shows that the alkali metal and rare earth metal modified Al2O3 support used in this invention has the effect of improving the yield of diethylenetriamine. The main reasons for this have been described in detail in the specification.

[0093] Compared to Example 1, Comparative Examples 2 and 3, which used rare earth metal and alkali metal-modified Al2O3 supports respectively, showed lower conversion rates and selectivity in the reaction of iminodiacetonitrile to diethylenetriamine compared to Example 1. However, compared to Comparative Example 1, the catalysts prepared in Comparative Examples 2 and 3 showed improved conversion rates and selectivity. This indicates that modifying the Al2O3 support with either an alkali metal or a rare earth metal helps to improve the yield of diethylenetriamine, but the improvement is limited. Furthermore, modifying the Al2O3 support with both alkali metals and rare earth metals simultaneously is more beneficial for improving the yield of diethylenetriamine.

[0094] Compared to Example 1, Comparative Examples 4-6 were supported catalysts with single nickel and single copper loadings, respectively. Comparative Examples 5-6 represented catalysts with different copper loadings. The selectivity of Comparative Example 4 was significantly lower than that of Example 1, while the selectivity and conversion rates of Comparative Examples 5 and 6 were also significantly reduced. It can be seen that single-supported copper metal does not possess catalytic activity for the reaction of iminodiacetonitrile to diethylenetriamine, while single-supported nickel metal exhibits some catalytic activity for the reaction, but with low selectivity.

[0095] Compared to Example 1, Comparative Examples 7 and 8 were supported catalysts with nickel-copper molar ratios of 15:1 and 5:1, respectively. When the nickel-copper molar ratio was 15:1, the catalyst activity remained essentially unchanged compared to Example 1, while the selectivity decreased significantly. However, compared to Comparative Example 4, the catalyst selectivity was improved, indicating that adding copper can improve the catalyst selectivity, and the copper content should not be too low. When the nickel-copper molar ratio was 5:1, both the catalyst selectivity and conversion rate decreased, indicating that the copper content should not be too high. Therefore, it can be concluded that the combination of nickel and copper is beneficial for improving the product yield in the reaction of iminodiacetonitrile to diethylenetriamine, and the ratio of nickel to copper exists within a certain range.

[0096] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

[0097] This background section is provided to generally present the context of the invention. The work of the currently named inventors, the work to the extent described in this background section, and aspects of this section that did not constitute prior art at the time of application are neither expressly nor impliedly acknowledged as prior art to the invention.

Claims

1. A supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine, characterized in that: The chemical composition of this catalyst is Ni-Cu-M2O-RO x / Al2O3, where M is a modified alkali metal and R is a rare earth metal; the catalyst is prepared by first modifying the Al2O3 support with alkali metal and rare earth metal to obtain modified M2O-RO. x / Al2O3, then modified M2O-RO x Ni-Cu-M2O-RO is obtained by loading a nickel-copper bimetallic active component onto Al2O3. x / Al2O3 catalyst, which is a supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine.

2. The supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine according to claim 1, characterized in that: The total metal loading is 10-25 wt% of the carrier mass.

3. The supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine according to claim 1, characterized in that: The alkali metal is at least one selected from Li, Na, K, Rb, Cs, and Fr; the alkali metal loading is 0.1~2 wt% based on M2O; the rare earth metal is at least one selected from La, Ce, Pr, Nd, and Eu; and the rare earth metal loading is 0.1~2 wt% based on RO. x The loading of rare earth metals is 1 to 5 wt%; in nickel-copper bimetallic compounds, the molar ratio of nickel to copper is 5:1 to 10:

1.

4. A method for preparing a supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine according to any one of claims 1-3, characterized in that... Includes the following steps: (a) Rare earth metals are prepared into nanosols, and then the nanosols are loaded onto an alumina support to obtain RO x / Al2O3 support; (b) The alkali metal salt solution is impregnated in the RO prepared in step (a) by an impregnation method. x M2O-RO modified with alkali metals and rare earth metals was obtained on an Al2O3 support. x / Al2O3 support, which is dried and calcined for later use; (c) Prepare a nickel / copper metal salt solution as an impregnation solution, and impregnate it onto the carrier prepared in step (b). Then, after drying, calcining, and reduction, obtain Ni-Cu-M2O-RO. x / Al2O3 catalyst.

5. The method for preparing a supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine according to claim 4, characterized in that, The method for synthesizing rare earth metal nanosols in step (a) is a hydrothermal synthesis method. The specific steps include: dissolving at least one of the rare earth precursor salt, structural stabilizer and homogeneous precipitant in water, mixing thoroughly and uniformly, and then obtaining monodisperse rare earth oxide nanosols through a hydrothermal reaction. The hydrothermal reaction temperature is 60~150℃ and the time is 2~48h.

6. The method for preparing a supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine according to claim 5, characterized in that: The rare earth precursor salt is any one or a mixture of nitrates or acetates of Ce, La, Pr, Nd, and Eu; the structural stabilizer is any one or a mixture of polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, and citric acid; the homogeneous precipitant is any one or a mixture of urea, hexamethylenetetramine, and dimethyl oxalate; the molar ratio of the rare earth precursor salt, the structural stabilizer, and the homogeneous precipitant is 1:0 to 1.5:0 to 10.

7. The method for preparing a supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine according to claim 4, characterized in that: The alkali metal salt mentioned in step (b) is any one or a mixture of nitrates, acetates, and carbonates of Li, Na, K, Rb, Cs, and Fr; the drying temperature is 60-120℃; the calcination temperature is 300-550℃; and the calcination time is 2-10 h.

8. The method for preparing a supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine according to claim 4, characterized in that: The nickel / copper metal salt solution mentioned in step (c) is selected from any one or a mixture of solutions of nitrates, acetates, carbonates, hydrochlorides, and sulfates; the drying temperature is 80-120℃; the calcination temperature is 300-550℃, and the calcination time is 2-10h; the reducing atmosphere is a hydrogen / argon mixture, the reduction temperature is 300-550℃, and the time is 2-6h.

9. The application of the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine according to any one of claims 1-3 or the supported catalyst for the hydrogenation of iminodiacetonitrile to diethylenetriamine prepared by any one of claims 4-8 in the reaction of hydrogenation of iminodiacetonitrile to diethylenetriamine.

10. The application according to claim 9, characterized in that: Ni-Cu-M2O-RO x The Al2O3 catalyst was tableted and placed in a high-pressure fixed-bed reactor to participate in the reaction; the reaction temperature was 60-200℃, the pressure was 5.0-20MPa, and the LHSV liquid hourly space velocity was 0.2-4 h⁻¹. -1 .

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