Process for the preparation of a low-temperature hydrogenation catalyst for hydrogen storage and its use in the hydrogenation of aromatic compounds

Abstract

This invention discloses a method for preparing a low-temperature hydrogenation catalyst for hydrogen storage and its application in the hydrogenation of aromatic compounds. The preparation method includes the following steps: S1, impregnating a γ-Al₂O₃ support in a pretreatment agent solution, allowing it to stand, and drying it to obtain a pretreated support, wherein the pretreatment agent includes a carbon source; S2, impregnating the pretreated support in an active metal impregnation solution, allowing it to stand, drying it, and calcining it to obtain a catalyst precursor, wherein the active metal is platinum and / or palladium; S3, impregnating the catalyst precursor in the auxiliary metal impregnation solution, allowing it to stand, drying it, and calcining it to obtain the hydrogenation catalyst, wherein the auxiliary metal is one or two of cobalt, molybdenum, nickel, and tungsten. The catalyst of this invention is not prone to carbon deposition during use and has high thermal stability.

Description

Technical Field

[0001] This invention belongs to the field of hydrogenation catalyst technology, specifically relating to a method for preparing a low-temperature hydrogenation catalyst for hydrogen storage and its application in the hydrogenation of aromatic compounds. Background Technology

[0002] Hydrogen energy is a crucial green strategic energy source, characterized by abundant resources, environmental friendliness, and high energy density, making it a vital component of future energy. Hydrogen energy applications encompass four main parts: hydrogen production, storage, transportation, and utilization. Among these, the safe and efficient storage and transportation of hydrogen are key to its large-scale application and represent a bottleneck. Organic liquid hydrogen storage, due to its high storage density and good safety performance, is the most promising hydrogen storage technology. However, organic liquid hydrogen storage technology involves both hydrogenation and dehydrogenation processes. The hydrogenation process, due to its strong exothermic nature and rapid reaction, is prone to catalyst carbon buildup and side reactions, leading to reduced catalyst activity or even deactivation, thus shortening the cycle life of the hydrogen storage material.

[0003] CN114797918B relates to a titanium dioxide-based hydrogenation catalyst material, its preparation method, and its application, belonging to the field of catalytic hydrogenation technology. First, a modified titanium dioxide catalyst promoter with a high specific surface area is synthesized via a one-step solvothermal method. This promoter not only provides dispersion and anchoring functions for the main catalyst but also alters the electronic structure of the main catalyst, thereby further enhancing its catalytic activity. Second, the main catalyst is loaded onto the catalyst promoter using the simplest impregnation-supported reduction method, ultimately obtaining the aforementioned highly active A / M-TiO2 catalyst with adjustable synergistic ratio. This invention features a simple and efficient preparation process, short cycle time, and reasonable cost, making it suitable for large-scale production and application. However, this technology employs a batch reaction with high reaction pressure, limiting its long-term usability.

[0004] Domínguez F, Sánchez J, Arteaga G, et al. Gallia as support of Pt in benzene hydrogenation reaction[J]. J. Mol. Catal. A: Chem., 2005, 228: 319-324. Domínguez et al. prepared platinum-based benzene hydrogenation catalysts by modifying Al2O3 with Ga as a support, and found that Pt had the best activity at 0.5%. However, the catalysts prepared by this method had poor stability in benzene hydrogenation and could not be used for long periods.

[0005] Lu SL, Lonergan WW, Bosco JP, et al. Low temperature hydrogenation of benzene and cyclohexene: A comparative study between γ-Al2O3 supported Pt-Co and Pt-Ni bimetallic catalysts[J]. J Catal, 2008(259):260-268. Lu SL et al. prepared bimetallic catalysts such as Pt-Co / γ-Al2O3 / Pt-Ni / γ-Al2O3 using an impregnation method with γ-Al2O3 as the support. They found that the bimetallic catalyst had higher benzene hydrogenation activity than the monometallic catalyst, achieving a benzene conversion rate of 60% at 70℃ and 1 atm. However, the catalyst's operating conditions were relatively mild, resulting in low catalyst activity.

[0006] CN107537587B relates to a catalyst treatment method using carbohydrates for carbon coating. The technical problem to be solved by this invention is the uneven Pt dispersion, easy coking of the catalyst, and poor activity and stability of the prior art. The provided catalyst and treatment method have the advantages of high Pt dispersion, non-acidic support, virtually no coking during the reaction process, high activity and high stability when used in the dehydrogenation reaction of low-carbon alkanes or organic liquid hydrogen storage materials. It can be used for the industrial treatment of dehydrogenation catalysts and hydrogenation catalysts. However, in the preparation process, carbon coating and metal loading are carried out simultaneously. Carbon may cover the metal surface, thereby reducing the metal utilization rate. Summary of the Invention

[0007] The purpose of this invention is to provide a method for preparing a low-temperature hydrogenation catalyst for hydrogen storage, so as to solve the problems that catalysts prepared by existing methods are prone to carbon deposition during the reaction, resulting in deactivation and insufficient stability at high temperatures.

[0008] Another objective of this invention is to provide an application of a low-temperature hydrogenation catalyst for hydrogen storage in the hydrogenation of aromatic compounds.

[0009] To achieve the above objectives, the present invention provides a method for preparing a low-temperature hydrogenation catalyst for hydrogen storage, comprising the following steps:

[0010] S1, the γ-Al2O3 support is impregnated in a pretreatment agent solution, allowed to stand, and dried to obtain a pretreated support, wherein the pretreatment agent includes a carbon source;

[0011] S2, the pretreated support is immersed in an active metal impregnation solution, allowed to stand, dried and calcined to obtain a catalyst precursor, wherein the active metal is platinum and / or palladium;

[0012] S3, the catalyst precursor is immersed in the auxiliary metal impregnation solution, left to stand, dried, and calcined to obtain the hydrogenation catalyst, wherein the auxiliary metal is one or two of cobalt, molybdenum, nickel, and tungsten.

[0013] The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to the present invention uses a γ-Al₂O₃ support with a specific surface area of ​​180–280 m². 2 / g, with a pore volume of 0.5–2.0 mL / g and a pore size of 2–20 nm. The shape of the γ-Al₂O₃ support is not particularly limited in this invention; it can be at least one of spherical, strip-shaped, cylindrical, and clover-shaped.

[0014] The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to the present invention, wherein the carbon source in step S1 is at least one selected from methanol, ethanol, isoamyl alcohol, petroleum ether, furfural, Tween 80, n-pentane, n-decane, and cyclohexane.

[0015] The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to the present invention further includes a silicon source and / or a titanium source as the pretreatment agent.

[0016] The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to the present invention comprises the following: the silicon source is at least one selected from tetraethyl orthosilicate, silicon acetate, triethoxysilane, methyldiethoxysilane, and dimethyldiethoxysilane; and the titanium source is at least one selected from tetrabutyl titanate, tetraethyl titanate, tetrapropyl titanate, tetraisobutyl titanate, isopropyl titanate, and titanium acetate.

[0017] In the preparation method of the low-temperature hydrogenation catalyst for hydrogen storage described in this invention, the mass of the pretreatment agent in step S1 is at most 12% of the mass of the γ-Al2O3 support, wherein the silicon source is calculated as SiO2 and the titanium source is calculated as TiO2.

[0018] The method for preparing the low-temperature hydrogenation catalyst for hydrogen storage according to the present invention comprises, based on the total weight of the hydrogenation catalyst as 100%, 0.01-3% active metal element and 0.05-5% auxiliary metal oxide.

[0019] The preparation method of the low-temperature hydrogenation catalyst for hydrogen storage according to the present invention includes an impregnation time of 3 to 24 hours in step S1 and a drying condition of drying at 100 to 150°C for 2 to 8 hours.

[0020] In the preparation method of the low-temperature hydrogenation catalyst for hydrogen storage described in this invention, the standing time in step S2 is 3-12 hours, the drying conditions are drying at 100-200℃ for 2-12 hours, and the calcination conditions are calcination at 400-600℃ for 4-12 hours.

[0021] In the preparation method of the low-temperature hydrogenation catalyst for hydrogen storage described in this invention, the standing time in step S3 is 4-16 hours, the drying conditions are drying at 120-220°C for 2-12 hours, and the calcination conditions are calcination at 400-600°C for 2-10 hours.

[0022] This invention does not emphasize the heating mode of the roasting process in steps S2 and S3, but programmed heating is preferred in this technical solution, with a heating rate of 2-6°C / min. The atmosphere during roasting can be one of the following gases: air, nitrogen, oxygen, or water vapor, with a gas space velocity of 0-20 min⁻¹. -1 .

[0023] The preparation method of the low-temperature hydrogenation catalyst for hydrogen storage according to the present invention has a pH of 0 to 3 for the active metal impregnation solution.

[0024] To achieve the above objectives, the present invention also provides an application of the aforementioned low-temperature hydrogenation catalyst for hydrogen storage in the hydrogenation of aromatic compounds.

[0025] The present invention relates to the application of the low-temperature hydrogenation catalyst for hydrogen storage in the hydrogenation of aromatic compounds, wherein the aromatic compounds include 1-3 ring aromatics containing or not containing N.

[0026] The application of the low-temperature hydrogenation catalyst for hydrogen storage described in this invention in the hydrogenation of aromatic compounds, wherein the 1-3-cyclic aromatic hydrocarbon contains 0-3 side chains with a length of 1-3 carbon atoms.

[0027] The application of the low-temperature hydrogenation catalyst for hydrogen storage described in this invention in the hydrogenation of aromatic compounds, wherein the hydrogenation reaction conditions are: temperature 60–200°C, pressure 1–4 MPa, and mass hourly space velocity (H₂S₀) 0.5–4 h⁻¹. -1 The hydrogen-to-oil molar ratio is 2–20.

[0028] Beneficial effects of this invention:

[0029] This invention achieves the formation of Al-O-Si and Al-O-Ti coordination structures by adding small amounts of organosilicon and organotitanium to an alumina support. This results in the high dispersion of substances such as silicon oxide and titanium oxide, which adhere to the alumina. Furthermore, it improves and optimizes the support structure, thereby affecting the migration and placement of active metals during the loading process, improving the dispersion of active metals, accelerating the contact rate between hydrogenation reactants and active metals, and accelerating the dissociation rate of hydrogenation products. This results in higher hydrogenation reaction conversion and selectivity. Moreover, research has shown that adding a carbon source separately during the support pretreatment process can also improve the activity of the catalyst.

[0030] The catalyst of this invention can also accelerate the conduction of reaction heat, mitigate the local exothermic phenomenon of the reaction, reduce the risk of catalyst deactivation, and thus increase the service life of the catalyst. The hydrogenation catalyst of this invention can reduce the cost of the catalyst while maintaining its activity by adding cobalt, molybdenum, nickel and tungsten as promoters. Moreover, this invention has the characteristics of easy control of preparation conditions and good product repeatability. Detailed Implementation

[0031] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0032] The carrier is a spherical agent with a content of 98 wt% γ-Al2O3 and a specific surface area of ​​250.1 m². 2 / g, pore volume is 0.99ml. / g, pore size is 13.8nm.

[0033] Catalyst hydrogenation performance evaluation: 10g of the prepared catalyst was loaded into a fixed-bed reactor, and the reaction device pressure was set to 2.0MPa and the mass hourly space velocity was 1h. -1 The hydrogen-to-oil molar ratio was 2, the temperature was 120℃, the feed pump was turned on after the temperature was raised, and samples were taken after running for 10 hours. The composition of the product was analyzed by GC-MS. The conversion rate of benzene hydrogenation and the selectivity for cyclohexane production were calculated based on the composition. The hydrogenation effect is listed in Table 1.

[0034] Example 1:

[0035] S1: Take 10.0g of carrier and soak it in a solution consisting of 0.404g of tetraethyl orthosilicate and 20.0g of ethanol on a shaker for 4 hours. After removing the residual solution, let it stand.

[0036] S2: The resulting mixed carrier is dried at 100℃ for 4 hours to obtain the mixed carrier for later use;

[0037] S3: Dissolve 0.216g of chloroplatinic acid in 20.0g of deionized water, then add 2.0g of 3mol / L hydrochloric acid solution and stir until a homogeneous solution is formed with a pH of 0.8. Take the mixed support obtained in S2, add the above solution, stir rapidly, and let it stand for 12h for impregnation. After removing the residual solution, dry the catalyst at 100℃ for 8h, and then incubate the dried catalyst at 500℃ for 2min. -1 The precursor for a low-temperature hydrogenation catalyst for hydrogen storage was obtained by calcination under a steam atmosphere for 4 hours.

[0038] S4: Dissolve 0.027g of nickel nitrate in 15.0g of deionized water and stir until a homogeneous solution is formed. Take the hydrogen storage catalyst precursor obtained in S3, add it to the above solution, stir rapidly, and let it stand for 10 hours to impregnate. Then remove the residual solution, dry the catalyst at 120℃ for 10 hours, and then incubate the dried catalyst at 450℃ for 1 minute. -1 The catalyst was calcined in air for 3 hours to obtain a low-temperature hydrogenation catalyst A-1 for hydrogen storage, which contained 0.79% platinum and 0.07% nickel oxide.

[0039] Example 2:

[0040] S1: Take 10.0g of carrier and place it in a solution consisting of 1.622g tetrabutyl titanate, 5.0g Tween 80 and 30.0g ethanol. Shake and soak for 4 hours. After removing the residual solution, let it stand.

[0041] S2: The resulting mixed carrier is dried at 100℃ for 4 hours to obtain the mixed carrier for later use;

[0042] S3: Dissolve 0.344g of palladium chloride in 25.0g of deionized water, then add 1.5g of 3mol / L hydrochloric acid solution and stir until a homogeneous solution is formed with a pH of 1. Take the mixed support obtained in S2, add the above solution and stir rapidly. Let it stand for 4 hours to soak. Then remove the residual solution and dry the catalyst at 130℃ for 4 hours. Calcine the dried catalyst at 400℃ under a 1min-1 water vapor atmosphere for 4 hours to obtain a low-temperature hydrogenation catalyst precursor for hydrogen storage.

[0043] S4: Dissolve 0.141g of cobalt nitrate in 20.0g of deionized water and stir until a homogeneous solution is formed. Take the hydrogen storage hydrogenation catalyst precursor obtained in S3, add it to the above solution, stir rapidly, and let it stand for 8 hours for impregnation. After removing the residual solution, dry the catalyst at 120℃ for 6 hours. Calcine the dried catalyst at 450℃ in an air atmosphere for 4 hours at 2 min⁻¹ to obtain low-temperature hydrogenation catalyst A-2 for hydrogen storage, wherein the palladium content is 1.62% and the cobalt oxide content is 0.34%.

[0044] Example 3:

[0045] S1: Take 10.0g of carrier and place it in a solution consisting of 3.222g of silicon acetate, 1.0g of n-pentane and 40.0g of ethanol. Shake and soak for 4 hours. After removing the residual solution, let it stand.

[0046] S2: The resulting mixed carrier is dried at 100℃ for 4 hours to obtain the mixed carrier for later use;

[0047] S3: Dissolve 0.001g of tetraammineplatinum nitrate in 15.0g of deionized water, then add 0.5g of 3mol / L hydrochloric acid solution and stir until a homogeneous solution is formed with a pH of 1.2. Take the mixed support obtained in S2, add the above solution and stir rapidly. Let it stand for 24h to soak. Then remove the residual solution and dry the catalyst at 110℃ for 10h. Calcine the dried catalyst at 500℃ for 4h to obtain the precursor of the low-temperature hydrogenation catalyst for hydrogen storage.

[0048] S4: Dissolve 0.099g of ammonium heptamolybdate in 15.0g of deionized water and stir until a homogeneous solution is formed. Take the hydrogen storage hydrogenation catalyst precursor obtained in S3, add it to the above solution, stir rapidly, and let it stand for 4 hours to impregnate. Then remove the residual solution and dry the catalyst at 120℃ for 4 hours. Calcine the dried catalyst at 400℃ in an air atmosphere for 1 min⁻¹ for 4 hours to obtain low-temperature hydrogenation catalyst A-3 for hydrogen storage, in which the platinum content is 0.01% and the molybdenum trioxide content is 0.79%.

[0049] Example 4:

[0050] S1: Take 10.0g of carrier and place it in a solution composed of 3.707g isopropyl titanate, 3.0g cyclohexane and 50.0g ethanol. Shake and soak for 4 hours. After removing the residual solution, let it stand.

[0051] S2: The resulting mixed carrier is dried at 100℃ for 4 hours to obtain the mixed carrier for later use;

[0052] S3: Dissolve 0.068g of palladium nitrate in 30.0g of deionized water, then add 2.5g of 3mol / L hydrochloric acid solution and stir until a homogeneous solution is formed with a pH of 0.7. Take the mixed support obtained in S2, add the above solution and stir rapidly. Let it stand for 12h for soaking. After removing the residual solution, dry the catalyst at 100℃ for 8h. Then calcine the dried catalyst at 500℃ in an air atmosphere for 3min-1 for 2h to obtain the precursor of low-temperature hydrogenation catalyst for hydrogen storage.

[0053] S4: Dissolve 0.419 g of ammonium metatungstate in 30.0 g of deionized water and stir until a homogeneous solution is formed. Take the hydrogen storage hydrogenation catalyst precursor obtained in S3, add it to the above solution, stir rapidly, and let it stand for 10 h for impregnation. Then remove the residual solution and dry the catalyst at 120 °C for 10 h. Calcine the dried catalyst at 450 °C in an air atmosphere at 1 min⁻¹ for 2 h to obtain low-temperature hydrogenation catalyst A-4 for hydrogen storage, wherein the palladium content is 0.27% and the tungsten trioxide content is 3.44%.

[0054] Example 5

[0055] Similar to Example 1, except that in step S1, only 20.0 g of ethanol was used to soak the support. The prepared catalyst contained 0.79% platinum and 0.07% nickel oxide.

[0056] Comparative Example 1:

[0057] Dissolve 0.434 g of chloroplatinic acid in 25.0 g of deionized water, then add 1.0 g of 3 mol / L hydrochloric acid solution and stir until a homogeneous solution is formed. Take 10 g of the support, add the above solution and stir rapidly. Let it stand for 12 h to soak. After removing the residual solution, dry the catalyst at 100 °C for 8 h. Then calcine the dried catalyst at 500 °C for 4 h to obtain the comparative hydrogenation catalyst B-1.

[0058] Comparative Example 2:

[0059] Dissolve 0.116 g of palladium nitrate in 25.0 g of deionized water, then add 1.5 g of 3 mol / L hydrochloric acid solution and stir until a homogeneous solution is formed. Take 10 g of the support, add the above solution and stir rapidly. Let it stand for 12 h to soak. After removing the residual solution, dry the catalyst at 100 °C for 8 h. Then calcine the dried catalyst at 500 °C for 4 h to obtain the comparative hydrogenation catalyst B-2.

[0060] Comparative Example 3

[0061] S1: Dissolve 0.216g of chloroplatinic acid in 20.0g of deionized water, then add 2.0g of 3mol / L hydrochloric acid solution and stir until a homogeneous solution is formed with a pH of 0.8. Take 10.0g of the support, add it to the above solution and stir rapidly. Let it stand for 12h to soak. Then remove the residual solution and dry the catalyst at 100℃ for 8h. Then, incubate the dried catalyst at 500℃ for 2min. -1 The precursor for a low-temperature hydrogenation catalyst for hydrogen storage was obtained by calcination under a steam atmosphere for 4 hours.

[0062] S2: Dissolve 0.027g of nickel nitrate in 15.0g of deionized water and stir until a homogeneous solution is formed. Take the hydrogen storage catalyst precursor obtained in S3, add it to the above solution, stir rapidly, and let it stand for 10 hours to impregnate. Then remove the residual solution, dry the catalyst at 120℃ for 10 hours, and then incubate the dried catalyst at 450℃ for 1 minute. -1 The catalyst was calcined in air for 3 hours to obtain low-temperature hydrogenation catalyst B-3 for hydrogen storage.

[0063] Comparative Example 4

[0064] S1: Take 10.0g of carrier and soak it in a solution consisting of 0.404g of tetraethyl orthosilicate and 20.0g of ethanol on a shaker for 4 hours. After removing the residual solution, let it stand.

[0065] S2: The resulting mixed carrier is dried at 100℃ for 4 hours to obtain the mixed carrier for later use;

[0066] S4: Dissolve 0.027g of nickel nitrate in 15.0g of deionized water and stir until a homogeneous solution is formed. Take the mixed support obtained in S2, add it to the above solution, stir rapidly, and let it stand for 10 hours to impregnate. Then remove the residual solution and dry the catalyst at 120℃ for 10 hours. Place the dried catalyst at 450℃ for 1 minute. -1 The precursor for a low-temperature hydrogenation catalyst for hydrogen storage was obtained by calcining in air atmosphere for 3 hours.

[0067] S3: Dissolve 0.216 g of chloroplatinic acid in 20.0 g of deionized water, then add 2.0 g of 3 mol / L hydrochloric acid solution and stir until a homogeneous solution is formed with a pH of 0.8. Take the hydrogen storage catalyst precursor obtained in S3, add it to the above solution, stir rapidly, and let it stand for 12 h for impregnation. After removing the residual solution, dry the catalyst at 100 °C for 8 h, and then incubate the dried catalyst at 500 °C for 2 min. -1 The catalyst B-4 for low-temperature hydrogenation for hydrogen storage was obtained by calcining under a steam atmosphere for 4 hours.

[0068] The results of the catalyst hydrogenation performance evaluation are shown in Table 1:

[0069] Table 1

[0070] project Conversion rate, wt% Selectivity, wt% Runtime, h Example 1 99 100 480 Example 2 99 100 450 Example 3 98 100 360 Example 4 98 100 320 Example 5 93 95 300 Comparative Example 1 88 97 310 Comparative Example 2 86 95 280 Comparative Example 3 92 95 260 Comparative Example 4 84 90 200

[0071] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a low-temperature hydrogenation catalyst for hydrogen storage, characterized in that, Includes the following steps: S1, the γ-Al2O3 support is impregnated in a pretreatment agent solution, allowed to stand, and dried to obtain a pretreated support, wherein the pretreatment agent includes a carbon source; S2, the pretreated support is immersed in an active metal impregnation solution, allowed to stand, dried and calcined to obtain a catalyst precursor, wherein the active metal is platinum and / or palladium; S3, the catalyst precursor is immersed in the auxiliary metal impregnation solution, left to stand, dried, and calcined to obtain the hydrogenation catalyst, wherein the auxiliary metal is one or two of cobalt, molybdenum, nickel, and tungsten.

2. The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to claim 1, characterized in that, The specific surface area of ​​the γ-Al₂O₃ support is 180–280 m². 2 / g, pore volume is 0.5~2.0mL / g, pore size is 2~20nm.

3. The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to claim 1, characterized in that, The carbon source mentioned in step S1 is at least one of methanol, ethanol, isoamyl alcohol, petroleum ether, furfural, Tween 80, n-pentane, n-decane, and cyclohexane.

4. The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to claim 1, characterized in that, The pretreatment agent also includes a silicon source and / or a titanium source.

5. The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to claim 4, characterized in that, The silicon source is at least one of tetraethyl orthosilicate, silicon acetate, triethoxysilane, methyldiethoxysilane, and dimethyldiethoxysilane; the titanium source is at least one of tetrabutyl titanate, tetraethyl titanate, tetrapropyl titanate, tetraisobutyl titanate, and titanium acetate.

6. The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to claim 4, characterized in that, The total mass of the silicon source and the titanium source is at most 12% of the mass of the γ-Al2O3 support, where the silicon source is calculated as SiO2 and the titanium source is calculated as TiO2.

7. The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to claim 1, characterized in that, Based on the total weight of the hydrogenation catalyst (100%), it contains 0.01-3% active metal element and 0.05-5% auxiliary metal oxide.

8. The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to claim 1, characterized in that, The soaking time in step S1 is 3 to 24 hours, and the drying conditions are drying at 100 to 150°C for 2 to 8 hours.

9. The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to claim 1, characterized in that, In step S2, the standing time is 3 to 12 hours, the drying conditions are drying at 100 to 200°C for 2 to 12 hours, and the calcination conditions are calcination at 400 to 600°C for 4 to 12 hours.

10. The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to claim 1, characterized in that, In step S3, the standing time is 4–16 hours, the drying conditions are 120–220°C for 2–12 hours, and the calcination conditions are 400–600°C for 2–10 hours.

11. The method for preparing a low-temperature hydrogenation catalyst for hydrogen storage according to claim 1, characterized in that, The pH of the active metal impregnation solution is 0 to 3.

12. The application of the low-temperature hydrogenation catalyst for hydrogen storage according to any one of claims 1 to 11 in the hydrogenation of aromatic compounds.

13. The application of the low-temperature hydrogenation catalyst for hydrogen storage according to claim 12 in the hydrogenation of aromatic compounds, characterized in that, The aromatic compounds include 1-3 ring aromatics, with or without nitrogen.

14. The application of the low-temperature hydrogenation catalyst for hydrogen storage according to claim 13 in the hydrogenation of aromatic compounds, characterized in that, The 1-3 ring aromatic hydrocarbons contain 0-3 side chains, with a side chain length of 1-3 carbons.

15. The application of the low-temperature hydrogenation catalyst for hydrogen storage according to claim 12 in the hydrogenation of aromatic compounds, characterized in that, The hydrogenation reaction conditions are: temperature 60–200℃, pressure 1–4 MPa, and mass hourly space velocity (H₂S) 0.5–4 h⁻¹. -1 The hydrogen-to-oil molar ratio is 2–20.