A catalyst for preparing 4-nitro-o-phenylenediamine or 1,2,4-triaminobenzene and a method for preparing the same

Abstract

The application provides a catalyst for preparing 4-nitro-o-phenylenediamine or 1,2,4-triaminobenzene and a preparation method thereof, and belongs to the field of catalysts. The catalyst is composed of a metal oxide carrier and an active metal; the active metal is bonded with oxygen atoms of the metal oxide carrier to form an active metal-O-metal oxide carrier metal interface, and the mass ratio of the active metal component to the metal oxide carrier is 0.01:100.00-1.00:100.00. The catalyst has low noble metal content, high catalytic activity, high catalytic selectivity and unexpected technical effects.

Description

Technical Field

[0001] This invention relates to the field of catalysts, and more specifically to a catalyst for preparing 4-nitro-o-phenylenediamine or 1,2,4-triaminobenzene and a method thereof. Background Technology

[0002] 4-Nitro-o-phenylenediamine is an important pharmaceutical and dye intermediate and a major raw material for the synthesis of 87 downstream products, including imidazoles and indolones. 4-Nitro-o-phenylenediamine is primarily derived from the selective hydrogenation of 2,4-dinitroaniline. Traditional chemical reduction methods using iron powder, sodium sulfide, and hydrazine hydrate suffer from severe waste problems and do not conform to the principles of green, economical, and sustainable chemical development. From the perspective of industry development trends and enterprise production needs, heterogeneous catalytic synthesis of functionalized amino compounds is a green and efficient method.

[0003] In 1980, Terpko and Heck first used the heterogeneous catalyst Pd / C with triethylammonium bicarbonate as the H source for the catalytic hydrogenation of aromatic nitro compounds, achieving a yield of only 49% for the hydrogenation of 2,4-dinitroaniline to 4-nitro-o-phenylenediamine. Subsequently, Alaimo and Storrin reported achieving a selectivity of up to 90% for 4-nitro-o-phenylenediamine using PtO2, 5wt% Rh / Al2O3, and 5wt% Rh / C catalysts, but this required the addition of a base (such as NH4OH), which was detrimental to subsequent separation. Yoshida et al. enhanced the selectivity of the target product 4-nitro-o-phenylenediamine by adjusting the CO2 pressure in a Pt / TiO2 catalytic system. When the CO2 pressure increased to 4 MPa, the selectivity of 4-nitro-o-phenylenediamine reached approximately 83%, but the conversion rate was only 10%. The low selectivity of the target product leads to high subsequent processing costs, and the high content of precious metals in the catalysts used makes them unsuitable for industrial applications. These are the main problems currently existing in heterogeneous hydrogenation methods.

[0004] Therefore, it is essential to develop a catalyst with low noble metal content and high efficiency for the selective hydrogenation of 2,4-dinitroaniline to prepare 4-nitro-o-phenylenediamine or 1,2,4-triaminobenzene. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention provides the following technical solutions.

[0006] In a first aspect, the present invention provides a catalyst.

[0007] A catalyst comprising a metal oxide support and an active metal; wherein the active metal is bonded to oxygen atoms of the metal oxide support to form a metal interface in the active metal-O-metal oxide support; wherein the active metal is at least one selected from Ru, Pt, Pd, Rh, and Ni; wherein the metal oxide support is at least one selected from α-Al₂O₃, γ-Al₂O₃, TiO₂, Fe₂O₃, Fe₃O₄, Co₂O₃, Co₃O₄, and ZnO; and wherein the mass ratio of the active metal to the metal oxide support is 0.01:100.00-1.00:100.00.

[0008] In some embodiments, the active metal is at least one selected from Ru, Pd, Rh, and Ni; and the metal oxide support is at least one selected from α-Al₂O₃, γ-Al₂O₃, TiO₂, Fe₂O₃, Fe₃O₄, Co₂O₃, Co₃O₄, and ZnO. In some embodiments, the active metal is at least one selected from Ru, Pd, Rh, and Ni; and the metal oxide support is at least one selected from α-Al₂O₃ and γ-Al₂O₃.

[0009] In some embodiments, the active metal is Pt; the metal oxide support is at least one selected from α-Al₂O₃, γ-Al₂O₃, TiO₂, Fe₂O₃, Fe₃O₄, Co₂O₃, Co₃O₄, and ZnO. In some embodiments, the active metal is Pt; the metal oxide support is at least one selected from α-Al₂O₃ and γ-Al₂O₃.

[0010] In some embodiments, the mass ratio of the active metal to the metal oxide support is 0.10:100.00-1.00:100.00. In some embodiments, the mass ratio of the active metal to the metal oxide support is 0.10:100.00-0.50:100.00. In some embodiments, the mass ratio of the active metal to the metal oxide support is 0.01:100.00, 0.05:100.00, 0.10:100.00, 0.50:100.00, or 1.00:100.00.

[0011] In some embodiments, the coordination number of the active metal-O in the interface is 2.1 to 4.5. In some embodiments, the coordination number of the active metal-O in the interface is 4.0 to 4.4. In some embodiments, the coordination number of the active metal-O in the interface is 2.1, 2.5, 3.0, 3.5, 4.0, 4.4, or 4.5.

[0012] In some embodiments, the bond length between the active metal and O bonded together in the interface is In some embodiments, the bond length between the active metal and O bonded together in the interface is or In some embodiments, the bond length between the active metal and O bonded together in the interface is

[0013] In some embodiments, the spatial distance between the farthest ends of the active metal and O bonded to each other at the interface in the catalyst is less than the distance between N in the NH2 group and the oxygen of the nitro group at position 4 in 2,4-dinitroaniline, and greater than or equal to the distance between N in the NH2 group and the oxygen of the nitro group at position 2.

[0014] In some embodiments, the spatial distance between the farthest ends of the active metal and O bonded together at the interface in the catalyst is... In some embodiments, the spatial distance between the farthest ends of the active metal and O bonded together at the interface in the catalyst is... or

[0015] In some embodiments, the active metal in the catalyst exists in the form of atomic clusters, with cluster sizes ranging from 0.5 nm to 2.0 nm. In some embodiments, the active metal in the catalyst exists in the form of atomic clusters, with cluster sizes of 0.5 nm, 1.0 nm, 1.5 nm, or 2.0 nm.

[0016] In a second aspect, the present invention provides a method for preparing the catalyst described in the first aspect.

[0017] A method for preparing the catalyst according to the first aspect, comprising:

[0018] (1) Dissolve the protective agent in an aqueous ethanol solution, add an aqueous solution containing the precursor salt of the active metal, mix, and obtain mixture 1;

[0019] (2) Add alkali and metal oxide carrier to mixture 1, stir evenly and then microwave to obtain mixture 2;

[0020] (3) Add a reducing agent to mixture 2, react, filter, wash, and vacuum dry to obtain a solid powder;

[0021] (4) The solid powder obtained in step (3) is calcined for the first time in an inert gas or nitrogen atmosphere to obtain the first calcined product;

[0022] (5) The first calcination product obtained in step (4) is calcined a second time in a mixture of hydrogen and nitrogen to obtain the catalyst.

[0023] In some embodiments, the protective agent includes at least one of polyvinylpyrrolidone, polyvinyl alcohol, and polyethylene glycol.

[0024] In some embodiments, the concentration of ethanol in the aqueous ethanol solution is 60% vol to 100% vol. In some embodiments, the concentration of ethanol in the aqueous ethanol solution is 60% vol, 65% vol, 70% vol, 75% vol, 80% vol, 85% vol, 90% vol, 95% vol, or 100% vol.

[0025] In some embodiments, 0.5 mg to 2.0 mg of the protective agent is added per 1 ml of the ethanol-water solution. In some embodiments, 0.50 mg to 1.50 mg of the protective agent is added per 1 ml of the ethanol-water solution. In some embodiments, 0.50 mg, 0.70 mg, 0.75 mg, 0.80 mg, 0.90 mg, 1.00 mg, 1.20 mg, 1.50 mg, 1.70 mg, or 2.00 mg of the protective agent is added per 1 ml of the ethanol-water solution.

[0026] In some embodiments, the content of the active metal in the precursor salt of the active metal in the aqueous solution of the precursor salt of the active metal is 0.01 g / ml to 0.05 g / ml. In some embodiments, the content of the active metal in the precursor salt of the active metal in the aqueous solution of the precursor salt of the active metal is 0.01 g / ml, 0.02 g / ml, 0.03 g / ml, 0.04 g / ml, or 0.05 g / ml.

[0027] In some embodiments, the precursor salt of the active metal includes ruthenium chloride, ruthenium acetate, palladium chloride, palladium nitrate, palladium acetate, chloroplatinic acid, rhodium chloride, rhodium nitrate, nickel nitrate, or nickel chloride.

[0028] In some embodiments, the alkali includes at least one of sodium hydroxide, potassium hydroxide, and ammonia water.

[0029] In some embodiments, the reducing agent includes at least one of hydrazine hydrate, formaldehyde, and ethylene glycol.

[0030] In some embodiments, the metal oxide support includes at least one selected from α-Al₂O₃, γ-Al₂O₃, TiO₂, Fe₂O₃, Fe₃O₄, Co₂O₃, Co₃O₄, and ZnO. In some embodiments, the metal oxide support is γ-Al₂O₃. 3、 α-Al₂O₃ or Co₃O₄. In some embodiments, the metal oxide support is γ-Al₂O₃.

[0031] In some embodiments, the mass ratio of the active metal to the metal oxide support in the precursor salt of the active metal is 0.0001:1.0000-0.0100:1.0000. In some embodiments, the mass ratio of the active metal to the metal oxide support in the precursor salt of the active metal is 0.0010:1.0000-0.0050:1.0000. In some embodiments, the mass ratio of the active metal to the metal oxide support in the precursor salt of the active metal is 0.0001:1.0000, 0.0005:1.0000, 0.0010:1.0000, 0.0050:1.0000, or 0.0100:1.0000. In some embodiments, the mass ratio of the active metal to the metal oxide support in the precursor salt of the active metal is 0.0010:1.0000.

[0032] In some embodiments, the mass ratio of the alkali to the metal oxide support is 0.05:1.00-0.25:1.00. In some embodiments, the mass ratio of the alkali to the metal oxide support is 0.10:1.00-0.25:1.00. In some embodiments, the mass ratio of the alkali to the metal oxide support is 0.05:1.00, 0.10:1.00, 0.15:1.00, 0.20:1.00, or 0.25:1.00.

[0033] In some embodiments, 7.5 ml to 35.0 ml of the reducing agent is added per 1 g of the metal oxide support. In some embodiments, 10.0 ml to 20.0 ml of the reducing agent is added per 1 g of the metal oxide support. In some embodiments, 7.5 ml, 8.0 ml, 9.0 ml, 10.0 ml, 11.0 ml, 12.0 ml, 15.0 ml, 20.0 ml, 25.0 ml, 30.0 ml, or 35.0 ml of the reducing agent is added per 1 g of the metal oxide support.

[0034] In some embodiments, the microwave power of the microwave processing is 200W-1200W. In some embodiments, the microwave power of the microwave processing is 200W, 250W, 300W, 350W, 400W, 450W, 500W, 550W, 600W, 650W, 700W, 750W, 800W, 850W, 900W, 950W, 1000W, 1050W, 1100W, 1150W, or 1200W.

[0035] In some embodiments, the microwave processing time is 0.5 min to 10.0 min. In some embodiments, the microwave processing time is 0.5 min, 1.0 min, 1.5 min, 2.0 min, 2.5 min, 3.0 min, 3.5 min, 4.0 min, 4.5 min, 5.0 min, 5.5 min, 6.0 min, 6.5 min, 7.0 min, 7.5 min, 8.0 min, 8.5 min, 9.0 min, 9.5 min, or 10 min.

[0036] In some embodiments, the reaction temperature is 25°C to 85°C. In some embodiments, the reaction temperature is 25°C to 35°C. In some embodiments, the reaction temperature is 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, or 85°C.

[0037] In some embodiments, the reaction time is 4h-48h. In some embodiments, the reaction time is 4h-24h. In some embodiments, the reaction time is 12h-24h. In some embodiments, the reaction time is 4h, 8h, 12h, 16h, 20h, 24h, 30h, 35h, 40h, or 48h.

[0038] In some embodiments, the washing is performed using ethanol and water.

[0039] In some embodiments, the vacuum drying temperature is 45°C to 65°C. In some embodiments, the vacuum drying temperature is 45°C, 50°C, 55°C, 60°C, or 65°C.

[0040] In some embodiments, the vacuum drying time is 6 hours to 10 hours. In some embodiments, the vacuum drying time is 6 hours, 7 hours, 8 hours, 9 hours, or 10 hours.

[0041] In some embodiments, the roasting temperature for the first roasting is 150°C to 380°C. In some embodiments, the roasting temperature for the first roasting is 300°C to 380°C. In some embodiments, the roasting temperature for the first roasting is 320°C to 380°C. In some embodiments, the roasting temperature for the first roasting is 150°C, 200°C, 250°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, or 380°C.

[0042] In some embodiments, the roasting time for the first roasting is 1 hour to 5 hours. In some embodiments, the roasting time for the first roasting is 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours.

[0043] In some embodiments, the heating rate of the first calcination is 2°C / min to 5°C / min. In some embodiments, the heating rate of the first calcination is 2°C / min, 3°C / min, 4°C / min, or 5°C / min.

[0044] In some embodiments, the second roasting temperature is 150°C to 380°C. In some embodiments, the second roasting temperature is 300°C to 380°C. In some embodiments, the second roasting temperature is 320°C to 380°C. In some embodiments, the second roasting temperature is 150°C, 200°C, 250°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, or 380°C.

[0045] In some embodiments, the second roasting time is 1 hour to 5 hours. In some embodiments, the second roasting time is 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours.

[0046] In some embodiments, the heating rate of the second calcination is 2°C / min to 5°C / min. In some embodiments, the heating rate of the second calcination is 2°C / min, 3°C / min, 4°C / min, or 5°C / min.

[0047] In some embodiments, the volume ratio of hydrogen to nitrogen in the hydrogen-nitrogen mixture is 1:99 to 10:90. In some embodiments, the volume ratio of hydrogen to nitrogen in the hydrogen-nitrogen mixture is 1:99, 2:99, 3:99, 4:99, 5:99, 6:99, 7:99, 8:99, 9:99, or 10:90.

[0048] Thirdly, the present invention provides an application of the catalyst described in the first aspect or the catalyst obtained by the preparation method described in the second aspect.

[0049] Application of the catalyst described in the first aspect or the catalyst obtained by the preparation method described in the second aspect as a catalyst in the reaction of catalyzing the preparation of 4-nitro-o-phenylenediamine or 1,2,4-triaminobenzene from 2,4-dinitroaniline.

[0050] Fourthly, the present invention provides a method for preparing 4-nitro-o-phenylenediamine.

[0051] A method for preparing 4-nitro-o-phenylenediamine, comprising: reacting 2,4-dinitroaniline with hydrogen in a solvent in the presence of the catalyst described in the first aspect or the catalyst obtained by the preparation method described in the second aspect to obtain 4-nitro-o-phenylenediamine; wherein the active metal in the catalyst described in the first aspect is at least one selected from Ru, Pd, Rh, and Ni; and the precursor salt of the active metal in the preparation method described in the second aspect includes ruthenium chloride, ruthenium acetate, palladium chloride, palladium nitrate, palladium acetate, rhodium chloride, rhodium nitrate, nickel nitrate, or nickel chloride.

[0052] In some embodiments, the reaction temperature is 90°C to 160°C. In some embodiments, the reaction temperature is 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 145°C, 150°C, 155°C, or 160°C.

[0053] In some embodiments, the reaction hydrogen pressure is 1.0 MPa-2.5 MPa. In some embodiments, the reaction hydrogen pressure is 1.0 MPa, 1.5 MPa, 2.0 MPa, or 2.5 MPa.

[0054] In some embodiments, the reaction solvent is an alcohol solvent.

[0055] In some embodiments, the alcohol solvent is selected from at least one of C1-C10 alcohol solvents. In some embodiments, the alcohol solvent is selected from at least one of C1, C2, C3, C4, C5, C6, C7, C8, C9, or C10 alcohol solvents.

[0056] In some embodiments, the alcohol solvent is at least one selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, or isobutanol.

[0057] In some embodiments, the method includes a reaction in a fixed-bed reactor, wherein the mass space velocity of the 2,4-dinitroaniline feed is 6 h⁻¹. -1 -26h -1 In some embodiments, the method includes reacting in a fixed-bed reactor, wherein the mass space velocity of the 2,4-dinitroaniline feed is 6 h⁻¹, calculated based on the mass of 2,4-dinitroaniline. -1 7h -1 8h -1 9h -1 10h -1 11h -1 12h -1 13h -1 14h -1 15h -1 16h-1 17h -1 18h -1 19h -1 20h -1 21h -1 22h -1 23h -1 24h -1 25h -1 or 26h -1 .

[0058] In some embodiments, 5 mg to 17 mg of the 2,4-dinitroaniline is added per 1 ml of solvent. In some embodiments, 5 mg, 6 mg, 7 mg, 8 mg, 9 mg, 10 mg, 11 mg, 12 mg, 13 mg, 14 mg, 15 mg, 16 mg, or 17 mg of the 2,4-dinitroaniline is added per 1 ml of solvent.

[0059] The catalytic mechanism of the catalyst described in this invention is as follows: When multiple reducible groups exist on the benzene ring, achieving the selective reduction of nitro groups has always been a research hotspot and challenge in the field of selective catalysis both domestically and internationally, especially for the highly selective reduction of dinitrobenzene compounds. In heterogeneous selective catalytic hydrogenation reactions, the specific adsorption of the substrate on the catalyst surface plays a crucial role in improving the selectivity of the target product. Therefore, in the selective hydrogenation of 2,4-dinitroaniline to prepare 4-nitro-o-phenylenediamine, achieving the selective adsorption of the 2-NO2 group is key. The inventors noted that the difference between the two -NO2 groups in the 2,4-dinitroaniline molecule lies in the -NH2 group next to the 2-NO2 group, and the N atom in the -NH2 group readily reacts with the metal M... δ+ Species coordination occurs, with the -NO2 group readily adsorbing onto the metal oxide support via the O atom. Furthermore, the spatial distance between the N atom of the -NH2 group and the O atom of the 2-NO2 group is approximately... Based on these molecular characteristics, the design concept of this invention is to introduce the M1-O-M2 interface (the metal interface in the active metal-O-metal oxide support) as an active site to achieve high activity and high selectivity in the production of 4-nitro-o-phenylenediamine from 2,4-dinitroaniline, i.e., M1 (active metal) forming M1 δ+ The -NH2 and 2-NO2 groups are adsorbed at the interface where the spatial distance between the most distant ends of the active metal and O in the interface is suitable. The 4-NO2 group is adsorbed on the support, achieving specific adsorption of the 2-NO2 group, thereby realizing selective hydrogenation of the 2-NO2 group (the 4-NO2 group adsorbed on the support does not add hydrogen, while the 2-NO2 group adsorbed between the active metal and O in the interface can add hydrogen).

[0060] Fifthly, the present invention provides a method for preparing 1,2,4-triaminobenzene.

[0061] A method for preparing 1,2,4-triaminobenzene, comprising: reacting 2,4-dinitroaniline with hydrogen in a solvent in the presence of the catalyst described in the first aspect or the catalyst obtained by the preparation method described in the second aspect to obtain 1,2,4-triaminobenzene; wherein the active metal in the catalyst described in the first aspect is Pt; and the precursor salt of the active metal in the preparation method described in the second aspect includes chloroplatinic acid.

[0062] In some embodiments, the reaction temperature is 90°C to 160°C. In some embodiments, the reaction temperature is 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 145°C, 150°C, 155°C, or 160°C.

[0063] In some embodiments, the reaction gas pressure is 1.0 MPa-2.5 MPa. In some embodiments, the reaction gas pressure is 1.0 MPa, 1.5 MPa, 2.0 MPa, or 2.5 MPa.

[0064] In some embodiments, the reaction solvent is an alcohol solvent.

[0065] In some embodiments, the alcohol solvent is selected from at least one of C1-C10 alcohol solvents. In some embodiments, the alcohol solvent is selected from at least one of C1, C2, C3, C4, C5, C6, C7, C8, C9, or C10 alcohol solvents.

[0066] In some embodiments, the alcohol solvent is at least one selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, or isobutanol.

[0067] In some embodiments, the method includes a reaction in a fixed-bed reactor, wherein the mass space velocity of the 2,4-dinitroaniline feed is 6 h⁻¹. -1 -26h -1 In some embodiments, the method includes reacting in a fixed-bed reactor, wherein the mass space velocity of the 2,4-dinitroaniline feed is 6 h⁻¹, calculated based on the mass of 2,4-dinitroaniline. -1 7h -1 8h -1 9h -1 10h -1 11h -1 12h -1 13h -1 14h -1 15h -116h -1 17h -1 18h -1 19h -1 20h -1 21h -1 22h -1 23h -1 24h -1 25h -1 or 26h -1 .

[0068] In some embodiments, 5 mg to 17 mg of the 2,4-dinitroaniline is added per 1 ml of solvent. In some embodiments, 5 mg, 6 mg, 7 mg, 8 mg, 9 mg, 10 mg, 11 mg, 12 mg, 13 mg, 14 mg, 15 mg, 16 mg, or 17 mg of the 2,4-dinitroaniline is added per 1 ml of solvent.

[0069] Beneficial effects

[0070] Compared with the prior art, a certain embodiment provided by the present invention has at least one of the following beneficial effects:

[0071] 1. The catalyst for the hydrogenation of 2,4-dinitroaniline to 4-nitro-o-phenylenediamine provided by the present invention uses the M1-O-M2 interface, which forms a homogeneous active metal-O interface with a suitable spatial distance between the farthest ends, as the hydrogenation active center, to achieve a selectivity of up to 98.1% for 4-nitro-o-phenylenediamine and reduce the subsequent separation cost.

[0072] 2. The catalyst for the hydrogenation of 2,4-dinitroaniline to 4-nitro-o-phenylenediamine or the preparation method of 1,2,4-triaminobenzene provided by this invention has the advantages of low precious metal content (weight ratio can be as low as 0.01%), good catalyst stability, and suitability for industrial production. This can greatly reduce the production cost of the catalyst and the hydrogenation to 4-nitro-o-phenylenediamine or 1,2,4-triaminobenzene.

[0073] 3. The catalyst provided by this invention has good catalytic activity stability and still has good catalytic activity and catalytic selectivity after continuous reaction for at least 51 hours.

[0074] 4. Compared with other microwave processing powers, using a microwave processing power of 200W-1200W is more conducive to improving the selectivity of the obtained catalyst.

[0075] 5. The catalyst provided by this invention is used to catalyze the preparation of 4-nitro-o-phenylenediamine or 1,2,4-triaminobenzene from 2,4-dinitroaniline without the need for the addition of alkali. The subsequent separation and purification are simple, the reaction requires low pressure, the reaction is mild, safe and environmentally friendly, and the conversion rate is high, the selectivity is high, and the sustainable utilization time is long, which has excellent technical effects.

[0076] Terminology Definition

[0077] The term “room temperature” refers to ambient temperature, which is 15°C-40°C in some embodiments, 20°C-35°C in some embodiments, and 25°C-30°C in some embodiments.

[0078] The term "loading" refers to the percentage of the mass of the active metal relative to the mass of the carrier (a metal oxide carrier in this invention).

[0079] In the foregoing description of this invention, all figures disclosed herein, whether or not the terms "about," "approximately," or "around" are used, are approximate values. Based on the disclosed figures, the value of each figure may vary by less than ±10% or by a difference that is considered reasonable by those skilled in the art, such as ±1%, ±2%, ±3%, ±4%, ±5%, or 10%.

[0080] The terms "above", "below", and "within" are understood to include the number itself. For example, "two or more" means ≥ two.

[0081] The term “and / or” should be understood to mean any one of the options or any combination of two or more of the options.

[0082] The term "wt%" indicates a percentage by mass.

[0083] The terms “vol%” or “%vol” represent volume percentage.

[0084] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples. Attached Figure Description

[0085] Figure 1The image shows an HRTEM image (high-resolution transmission electron microscopy image) of the 0.5% Ru / γ-Al2O3 catalyst obtained in Example 1.

[0086] Figure 2 The XANES (near-edge absorption spectrum) (Figure a) and EXAFS (extended X-ray absorption fine structure) (Figure b) spectra of the 0.5% Ru / γ-Al2O3 catalyst (sample) and ruthenium foil and ruthenium oxide (RuO2) obtained in Example 1 are shown.

[0087] Figure 3 This is a schematic diagram illustrating the specific adsorption and hydrogenation mechanism of 2,4-dinitroaniline on the surface of the catalyst described in this invention. Detailed Implementation

[0088] To enable those skilled in the art to better understand the technical solutions of the present invention, some non-limiting embodiments are further disclosed below to provide a more detailed description of the present invention.

[0089] All reagents used in this invention can be purchased commercially or prepared by the methods described in this invention.

[0090] Unless otherwise stated, the polyvinylpyrrolidone described in the following embodiments or comparative examples of the present invention is of type PVPK30.

[0091] Example 1

[0092] Catalyst preparation:

[0093] (1) Dissolve 30 mg PVP (polyvinylpyrrolidone) in 40 ml of ethanol aqueous solution (ethanol to water volume ratio of 3:1), add 0.5 ml RuCl3 solution (i.e., aqueous solution of precursor salt of active metal; Ru mass concentration of 0.01 g / mL), stir for 10 min to mix, and obtain mixture 1;

[0094] (2) Add 0.1g sodium hydroxide and 1g γ-Al2O3 carrier to mixture 1 in sequence, stir evenly, and then microwave treat for 4min at 800W microwave power to obtain mixture 2;

[0095] (3) Add 10 ml of hydrazine hydrate to mixture 2, react at 25 °C for 24 h, filter, wash with ethanol and water in sequence, and dry under vacuum at 60 °C for 10 h to obtain solid powder.

[0096] (4) The solid powder obtained in step (3) is calcined for the first time in a nitrogen atmosphere at a temperature of 350°C for 3 hours to obtain the first calcined product.

[0097] (5) The first calcination product obtained in step (4) is subjected to a second calcination in a mixture of hydrogen and nitrogen (volume ratio of hydrogen to nitrogen is 5:95) at a calcination temperature of 250°C for 1 hour to obtain the 0.5% Ru / γ-Al2O3 catalyst. The 0.5% Ru / γ-Al2O3 catalyst obtained in this example is then subjected to catalyst performance testing under the following conditions:

[0098] Catalyst performance testing:

[0099] The catalytic reaction was carried out in a fixed-bed reactor: under the conditions of reaction temperature of 150℃, reaction pressure of 1.5MPa, and hydrogen atmosphere, 0.3g of the catalyst to be tested was added to the fixed-bed reactor, and the reaction was carried out at a mass hourly space velocity of 16h⁻¹. -1 A methanol solution of 2,4-dinitroaniline with a concentration of 0.01 g / ml was introduced at a rate of (based on 2,4-dinitroaniline). After 1 hour of reaction, a sample was taken to detect the content of hydrogenation products. The conversion rate of the reaction substrate and the selectivity of the products were calculated. The test results are shown in Table 1.

[0100] Example 2

[0101] The catalyst was prepared according to Example 1, except that 0.5 ml RuCl3 solution (Ru mass concentration of 0.01 g / mL) was replaced with 0.5 ml palladium chloride solution (Pd mass concentration of 0.01 g / mL), sodium hydroxide was replaced with potassium hydroxide, the microwave power was changed from 800 W to 1200 W, the microwave treatment time was changed from 4 min to 0.5 min, hydrazine hydrate was replaced with formaldehyde solution, and the catalyst was heated and stirred under reflux at 85 °C for 6 h. The remaining conditions were the same as those in Example 1, resulting in a 0.5% Pd / γ-Al2O3 catalyst. The 0.5% Pd / γ-Al2O3 catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 1.

[0102] Example 3

[0103] The catalyst was prepared according to Example 1, except that 0.5 ml of RuCl3 solution (Ru mass concentration of 0.01 g / mL) was replaced with 0.5 ml of chloroplatinic acid solution (Pt mass concentration of 0.01 g / mL), and the remaining conditions were the same as those in Example 1. A 0.5% Pt / γ-Al2O3 catalyst was then prepared. The 0.5% Pt / γ-Al2O3 catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 1.

[0104] Example 4

[0105] The catalyst was prepared according to Example 1, except that 0.5 ml of RuCl3 solution (Ru mass concentration of 0.01 g / mL) was replaced with 0.5 ml of rhodium chloride solution (Rh mass concentration of 0.01 g / mL), and sodium oxide was replaced with ammonia water. The remaining conditions were the same as those in Example 1, resulting in a 0.5% Rh / γ-Al2O3 catalyst. The 0.5% Rh / γ-Al2O3 catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 1.

[0106] Example 5

[0107] The catalyst was prepared according to Example 1, except that 0.5 ml of RuCl3 solution (Ru mass concentration of 0.01 g / mL) was replaced with 0.5 ml of nickel chloride solution (Ni mass concentration of 0.01 g / mL), and the remaining conditions were the same as those in Example 1. A 0.5% Ni / γ-Al2O3 catalyst was then prepared. The 0.5% Ni / γ-Al2O3 catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 1.

[0108] Table 1: Hydrogenation performance of 2,4-dinitroaniline with 0.5% M1 / γ-Al2O3 supported trace noble metal catalyst

[0109]

[0110] in conclusion:

[0111] (1) The 0.5% Ru / γ-Al2O3 catalyst, 0.5% Pd / γ-Al2O3 catalyst, 0.5% Rh / γ-Al2O3 catalyst and 0.5% Ni / γ-Al2O3 catalyst provided by the present invention have good selectivity for 4-nitro-o-phenylenediamine and high activity, and high conversion rate for 2,4-dinitroaniline; among which, the 0.5% Ru / γ-Al2O3 catalyst and the 0.5% Pd / γ-Al2O3 catalyst are preferred, which have higher conversion rate and selectivity.

[0112] (2) The 0.5% Pt / γ-Al2O3 catalyst provided by the present invention has good selectivity for 1,2,4-triaminobenzene and high activity, and high conversion rate for 2,4-dinitroaniline.

[0113] Example 6

[0114] The catalyst was prepared according to Example 1, except that 0.5 ml of RuCl3 solution (Ru mass concentration of 0.01 g / mL) was replaced with 0.1 ml of RuCl3 solution (Ru mass concentration of 0.01 g / mL), and the remaining conditions were the same as those in Example 1. A 0.1% Ru / γ-Al2O3 catalyst was thus obtained. The 0.1% Ru / γ-Al2O3 catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 2.

[0115] Example 7

[0116] The catalyst was prepared according to Example 6, except that 1g of γ-Al2O3 was replaced with 1g of α-Al2O3, and the remaining conditions were the same as those in Example 6, to obtain a 0.1% Ru / α-Al2O3 catalyst. The 0.1% Ru / α-Al2O3 catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 2.

[0117] Example 8

[0118] The catalyst was prepared according to Example 6, except that 1g of γ-Al2O3 was replaced with 1g of TiO2, and the remaining conditions were the same as those in Example 6, to obtain a 0.1% Ru / TiO2 catalyst. The 0.1% Ru / TiO2 catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 2.

[0119] Example 9

[0120] The catalyst was prepared according to Example 6, except that 1g of γ-Al2O3 was replaced with 1g of Fe3O4, and the other conditions were the same as those in Example 6, to obtain 0.1% Ru / Fe3O4. The 0.1% Ru / Fe3O4 catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 2.

[0121] Example 10

[0122] The catalyst was prepared according to Example 6, except that 1g of γ-Al2O3 was replaced with 1g of Co3O4, and the other conditions were the same as those in Example 6, to obtain a 0.1% Ru / Co3O4 catalyst. The 0.1% Ru / Co3O4 catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 2.

[0123] Example 11

[0124] The catalyst was prepared according to Example 6, except that 1g of γ-Al₂O₃ was replaced with 1g of ZnO, and the remaining conditions were the same as those in Example 6, to obtain a 0.1% Ru / ZnO catalyst. The 0.1% Ru / ZnO catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 2.

[0125] Table 2: Test results of 2,4-dinitroaniline hydrogenation performance of catalysts with 0.1% Ru loading on different supports

[0126]

[0127]

[0128] Conclusion: The present invention uses γ-Al2O3, α-Al2O3, TiO2, Fe3O4, Co3O4, or ZnO as catalyst supports, all of which are beneficial to improving the selectivity of 4-nitro-o-phenylenediamine under the condition of low active metal content. Among them, γ-Al2O3, α-Al2O3, or Co3O4 are preferred as catalyst supports, more preferably γ-Al2O3 or α-Al2O3, which are beneficial to improving the selectivity of 4-nitro-o-phenylenediamine. The most preferred is γ-Al2O3, which is beneficial to improving the selectivity of 4-nitro-o-phenylenediamine and also to improving the conversion rate of 2,4-dinitroaniline.

[0129] Example 12

[0130] The catalyst was prepared according to Example 1, except that 0.5 ml of RuCl3 solution (Ru mass concentration of 0.01 g / mL) was replaced with 1 ml of RuCl3 solution (Ru mass concentration of 0.01 g / mL), and the remaining conditions were the same as those in Example 1. A 1% Ru / γ-Al2O3 catalyst was then prepared. The 1% Ru / γ-Al2O3 catalyst obtained in this example was used for catalyst performance testing under the same conditions as in Example 1. The test results are shown in Table 3.

[0131] Table 3: Comparison of 2,4-dinitroaniline hydrogenation performance of Ru / γ-Al2O3 catalysts with different active metal loadings

[0132]

[0133] Conclusion: The present invention preferably uses an active metal loading of about 0.1%, which is beneficial to improving the selectivity of 4-nitro-o-phenylenediamine.

[0134] Comparative Example 1: Investigation of Preparation Method

[0135] Take 2.5 ml of deionized water, add 0.5 ml of RuCl3 solution (Ru mass concentration of 0.01 g / mL), stir until homogeneous, and while stirring, add 1 g of γ-Al2O3 support, stir until homogeneous, and let stand at room temperature for 24 h. Then dry at 100 °C overnight to obtain solid powder; calcine the solid powder in a 10% H2 / N2 mixed gas (i.e., H2 to N2 volume ratio of 10:90) at 500 °C for 2 h to obtain 0.5% Ru / γ-Al2O3-im catalyst. The 0.5% Ru / γ-Al2O3-im catalyst obtained in this comparative example was used for catalyst performance testing, and the test conditions were the same as those for the catalyst performance test in Example 1. The test results are shown in Table 4.

[0136] Comparative Example 2

[0137] The catalyst was prepared according to Example 1, without the addition of sodium hydroxide, and under the same conditions as the catalyst preparation method in Example 1, yielding 0.5% Ru / γ-Al2O3-no. The 0.5% Ru / γ-Al2O3-no catalyst obtained in this comparative example was used for catalyst performance testing under the same conditions as the catalyst performance test in Example 1. The test results are shown in Table 4.

[0138] Comparative Examples 3-5: Investigation of Microwave Processing

[0139] Comparative Example 3: Compared with Example 6, Comparative Example 3 did not use microwave treatment in step (2), but the remaining operations were the same as in Example 6, resulting in a 0.1% Ru / γ-Al2O3-0W catalyst. The 0.1% Ru / γ-Al2O3-0W catalyst obtained in this comparative example was used for catalyst performance testing under the same conditions as the catalyst performance test in Example 1. The test results are shown in Table 4.

[0140] Comparative Example 4: Compared with Example 6, the microwave power of the microwave treatment in step (2) of Comparative Example 3 was adjusted to 100W, and the remaining operations were the same as in Example 6, resulting in 0.1%Ru / γ-Al2O3-100W. The 0.1%Ru / γ-Al2O3-100W catalyst obtained in this comparative example was used for catalyst performance testing. The test conditions were the same as those for the catalyst performance test in Example 1, and the test results are shown in Table 4.

[0141] Comparative Example 5: Compared with Example 6, the microwave power of the microwave treatment in step (2) of Comparative Example 3 was adjusted to 1500W, and the remaining operations were the same as in Example 6, resulting in 0.1%Ru / γ-Al2O3-1500W. The 0.1%Ru / γ-Al2O3-1500W catalyst obtained in this comparative example was used for catalyst performance testing. The test conditions were the same as those for the catalyst performance test in Example 1, and the test results are shown in Table 4.

[0142] Table 4: Test results of 2,4-dinitroaniline hydrogenation performance of catalysts from Comparative Examples 3-5

[0143]

[0144] in conclusion:

[0145] (1) Compared with catalysts that do not have the metal interface structure in the active metal-O-metal oxide support described in the above embodiments and catalysts obtained without adding alkali in the preparation of catalysts, the catalyst prepared in this invention has a suitable M1-O-M2 interface and a suitable spatial distance, which is crucial for improving the selectivity of 4-nitro-o-phenylenediamine.

[0146] (2) Compared with other microwave power ranges, the catalyst obtained by microwave treatment with the microwave power (200W-1200W) provided by the present invention has higher selectivity for 4-nitro-o-phenylenediamine.

[0147] Example 13: HRTEM, XANES, and EXAFS spectral detection

[0148] The catalyst (sample) obtained in Example 1 was analyzed using HRTEM, XANES, and EXAFS spectra, and the results are as follows: Figure 1 and Figure 2 As shown. Separately, ruthenium foil (Ru foil) and ruthenium oxide (RuO2) were used to detect XANES and EXAFS spectra.

[0149] Results: See results below. Figure 2 See Table 5.

[0150] Table 5: Fitting parameters for Ru K-edge EXAFS data

[0151]

[0152] a CN, coordination number;

[0153] b R, the distance to the neighboring atom (bond length);

[0154] c σ 2 The Mean Square Relative Displacement (MSRD) (the degree of disorder in a system);

[0155] dΔE0, inner potential correction; (energy correction);

[0156] R factor indicates the goodness of the fit.

[0157] S0 2 Based on the EXAFS fitting of the reference sample, S0 2 Fixed at 1.016.

[0158] The HRTEM spectrum shows that the active metal in the catalyst obtained in Example 1 exists in the form of atomic clusters, with a cluster size of 0.5 nm to 2 nm.

[0159] This invention obtains a suitable M1-O bond length by employing ruthenium species in appropriate oxidation states and by using screened process parameters. (The bond length of the active metal-O in the metal interface of the active metal-O-metal oxide support), forming a suitable M1-O-M2 interface (the metal interface in the active metal-O-metal oxide support), and a suitable spatial distance between the farthest ends of the active metal-O in the interface (the spatial distance between the farthest ends of the mutually bonded active metal and O in the interface of the catalyst is less than the distance between N in the NH2 group and the oxygen of the nitro group at position 4 in 2,4-dinitroaniline (the distance between N in the NH2 group and the oxygen of the nitro group at position 4 in 2,4-dinitroaniline is approximately 6.35 Å), and greater than or equal to the distance between N in the NH2 group and the oxygen of the nitro group at position 2, which can be considered as When using the catalyst provided by this invention to catalyze the preparation of 4-nitro-o-phenylenediamine from 2,4-dinitroaniline, the 2-NO2 and -NH2 groups are jointly adsorbed onto the active metal-O surface of the catalyst interface. The distance between the oxygen in the 2-NO2 group and the N in the -NH2 group is 2.6 angstroms. The metal interface in the active metal-O-metal oxide support of the catalyst provided by this invention allows the 2-NO2 and -NH2 groups to be adsorbed precisely. Too large or too small a space will reduce the adsorption difference between the 2-NO2 and 4-NO2 groups and the catalyst, thereby decreasing selectivity.

[0160] Example 14: Investigation of catalyst activity and stability

[0161] The catalysts obtained in the above examples and comparative examples were reacted for 52 hours according to the catalyst performance testing procedure described in Example 1. Samples were taken to detect the content of hydrogenation products, the conversion rate of the reaction substrate and the selectivity of the products were calculated, and the activity and stability of the catalysts were tested. The results are shown in Table 6.

[0162] Table 6: Catalyst Activity and Stability Study

[0163]

[0164]

[0165] Conclusion: The catalyst provided by this invention has excellent catalytic activity stability and catalytic selectivity, and still has good catalytic activity and catalytic selectivity after continuous use for at least 51 hours.

[0166] The method of this invention has been described through preferred embodiments. Those skilled in the art will readily be able to modify or appropriately alter and combine the methods and applications described herein within the scope, spirit, and context of this invention to implement and apply the technology of this invention. Those skilled in the art can refer to the content herein to appropriately improve process parameters. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of this invention.

Claims

1. A catalyst for catalyzing the preparation of 4-nitro-o-phenylenediamine or 1,2,4-triaminobenzene from 2,4-dinitroaniline, characterized in that, The catalyst is composed of a metal oxide support and an active metal; the active metal bonds to the oxygen atoms of the metal oxide support, forming a metal interface between the active metal and the metal oxide support; the active metal is at least one of Ru, Pt, Pd, Rh, and Ni; the metal oxide support is at least one of α-Al₂O₃, γ-Al₂O₃, TiO₂, Fe₂O₃, Fe₃O₄, Co₂O₃, Co₃O₄, and ZnO; the mass ratio of the active metal to the metal oxide support is 0.01:100.00-1.00:100.00; the coordination number of the active metal-O in the interface is 2.1 to 4.5; the bond length between the active metal and O in the interface is 1.9 Å to 2.1 Å. The method for preparing the catalyst includes: (1) Dissolve the protective agent in an aqueous ethanol solution, add an aqueous solution containing an active metal precursor salt, mix, and obtain mixture 1; wherein the protective agent includes at least one of polyvinylpyrrolidone, polyvinyl alcohol, and polyethylene glycol; (2) Add alkali and metal oxide carrier to mixture 1, stir evenly and then microwave treat to obtain mixture 2; the microwave output power of the microwave treatment is 200W-1200W; the microwave treatment time is 0.5min-10.0min; (3) Add a reducing agent to mixture 2, react, filter, wash, and vacuum dry to obtain a solid powder; (4) The solid powder obtained in step (3) is calcined for the first time in an inert gas or nitrogen atmosphere to obtain the first calcined product; (5) The first calcination product obtained in step (4) is calcined a second time in a mixture of hydrogen and nitrogen to obtain the catalyst.

2. The catalyst according to claim 1, wherein the spatial distance between the farthest ends of the active metal and O bonded to each other at the interface of the catalyst is less than the distance between N in the NH2 group and the oxygen of the nitro group at position 4 in 2,4-dinitroaniline, and is greater than or equal to the distance between N in the NH2 group and the oxygen of the nitro group at position 2.

3. The catalyst according to claim 1, wherein the spatial distance between the farthest ends of the active metal and O bonded to each other at the interface in the catalyst is 1.9 Å to 2.8 Å.

4. The catalyst according to any one of claims 1-3, wherein the active metal in the catalyst exists in the form of atomic clusters, the cluster size being 0.5 nm to 2.0 nm.

5. A method for preparing the catalyst according to any one of claims 1-4, comprising: (1) Dissolve the protective agent in an aqueous ethanol solution, add an aqueous solution containing an active metal precursor salt, mix, and obtain mixture 1; wherein the protective agent includes at least one of polyvinylpyrrolidone, polyvinyl alcohol, and polyethylene glycol; (2) Add alkali and metal oxide carrier to mixture 1, stir evenly and then microwave treat to obtain mixture 2; the microwave output power of the microwave treatment is 200W-1200W; the microwave treatment time is 0.5min-10.0min; (3) Add a reducing agent to mixture 2, react, filter, wash, and vacuum dry to obtain a solid powder; (4) The solid powder obtained in step (3) is calcined for the first time in an inert gas or nitrogen atmosphere to obtain the first calcined product; (5) The first calcination product obtained in step (4) is calcined a second time in a mixture of hydrogen and nitrogen to obtain the catalyst.

6. The preparation method according to claim 5, The concentration of ethanol in the aqueous ethanol solution is 60% vol to 100% vol; and / or Add 0.50 mg to 2.00 mg of the protective agent per 1 ml of the ethanol aqueous solution; and / or The active metal in the precursor salt of the active metal in the aqueous solution of the precursor salt of the active metal is 0.01 g / mL - 0.05 g / mL; and / or The precursor salt of the active metal includes at least one of ruthenium chloride, ruthenium acetate, palladium chloride, palladium nitrate, palladium acetate, chloroplatinic acid, rhodium chloride, rhodium nitrate, nickel nitrate, or nickel chloride; and / or The alkali includes at least one of sodium hydroxide, potassium hydroxide, and ammonia water; and / or The reducing agent includes at least one of hydrazine hydrate, formaldehyde, and ethylene glycol; and / or The mass ratio of the active metal to the metal oxide support in the precursor salt of the active metal is 0.0001:1.0000-0.0100:1.0000; and / or The mass ratio of the alkali to the metal oxide support is 0.05:1.00-0.25:1.00; and / or For every 1g of the metal oxide support, add 7.5mL-35.0mL of the reducing agent; and / or The reaction temperature is 25℃~85℃; and / or The reaction time is 4-48 hours; and / or The washing process involves using ethanol and water; and / or The vacuum drying temperature is 45℃~65℃; and / or The vacuum drying time is 6 h to 10 h; and / or The roasting temperature for the first roasting is 150℃~380℃; and / or The roasting time for the first roasting is 1 h to 5 h; and / or The heating rate for the first calcination is 2°C / min to 5°C / min; and / or The second roasting temperature is 150℃~380℃; and / or The second roasting time is 1 h to 5 h; and / or The heating rate for the second roasting is 2°C / min to 5°C / min; and / or The volume ratio of hydrogen to nitrogen in the hydrogen-nitrogen mixture is 1:99 to 10:

90.

7. According to the preparation method of claim 5, the mass ratio of the active metal to the metal oxide support in the precursor salt of the active metal is 0.0010:1.0000-0.0050:1.0000.

8. The use of the catalyst according to any one of claims 1-4 or the catalyst obtained by the preparation method according to any one of claims 5-7 as a catalyst in the reaction of catalyzing the preparation of 4-nitro-o-phenylenediamine or 1,2,4-triaminobenzene from 2,4-dinitroaniline.

9. A method for preparing 4-nitro-o-phenylenediamine, comprising: 2,4-Dinitroaniline reacts with hydrogen in a solvent in the presence of the catalyst described in any one of claims 1-4 or the catalyst obtained by the preparation method described in any one of claims 5-7 to give 4-nitro-o-phenylenediamine; The active metal in the catalyst according to any one of claims 1-4 is at least one of Ru, Pd, Rh, and Ni; the precursor salt of the active metal in the preparation method according to any one of claims 5-7 includes at least one of ruthenium chloride, ruthenium acetate, palladium chloride, palladium nitrate, palladium acetate, rhodium chloride, rhodium nitrate, nickel nitrate, or nickel chloride.

10. The method according to claim 9, wherein the reaction temperature is 90°C to 160°C; and / or The reaction hydrogen pressure is 1.0 MPa - 2.5 MPa; and / or The reaction solvent is an alcohol solvent; and / or The method includes a reaction in a fixed-bed reactor, with the mass hourly space velocity (MSV) of the 2,4-dinitroaniline feed being 6 h⁻¹. -1 -26h -1 .

11. The method according to claim 10, wherein the alcohol solvent is selected from at least one of C1-C10 alcohol solvents.

12. The method according to claim 10, wherein the alcohol solvent is at least one selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, or isobutanol.

13. The method according to any one of claims 9-12, wherein 5 mg-17 mg of the 2,4-dinitroaniline is added per 1 mL of solvent.

14. A method for preparing 1,2,4-triaminobenzene, comprising: 2,4-Dinitroaniline reacts with hydrogen in a solvent in the presence of the catalyst described in any one of claims 1-4 or the catalyst obtained by the preparation method described in any one of claims 5-7 to give 1,2,4-triaminobenzene; wherein the active metal in the catalyst described in any one of claims 1-4 is Pt; and the precursor salt of the active metal in the preparation method described in any one of claims 5-7 includes chloroplatinic acid.

15. The method according to claim 14, wherein the reaction temperature is 90°C to 160°C.

16. The method according to claim 14, wherein the reaction pressure is 1.0 MPa - 2.5 MPa.

17. The method according to claim 14, wherein the reaction solvent is an alcohol solvent.

18. The method according to claim 17, wherein the alcohol solvent is selected from at least one of C1-C10 alcohol solvents.

19. The method according to claim 17, wherein the alcohol solvent is at least one selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, or isobutanol.

20. The method of claim 14, wherein the method comprises carrying out the reaction in a fixed-bed reactor, wherein the mass space velocity of the 2,4-dinitroaniline feed is 6 h⁻¹, calculated based on the mass of 2,4-dinitroaniline. -1 -26h -1 .

21. The method according to claim 14, wherein 5 mg to 17 mg of the 2,4-dinitroaniline is added per 1 mL of solvent.

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