A MgH2 & multivalent titanium composite hydrogen storage material and large-scale preparation method

Abstract

The present application relates to the technical field of hydrogen storage materials, and specifically discloses a MgH2 & multivalent titanium composite hydrogen storage material and a large-scale preparation method. The MgH2 & multivalent titanium composite hydrogen storage material includes: 3-7% titanium-based catalytic material and 93-97% MgH2, and the titanium-based catalytic material includes magnesium powder and nano-rutile phase titanium dioxide particles in a mass ratio of 1: (0.9-1.2). Its large-scale preparation method includes the following steps: under a 9.5-10.5pa argon environment, the magnesium powder is heated to 680-750°C for melting to obtain magnesium water; the magnesium water and nano-rutile phase titanium dioxide particles are mixed, the temperature is raised to 1300°C, and the reaction is carried out for 60-120min to obtain a reaction solution; the reaction solution is cooled to room temperature to obtain a titanium-based catalytic material; the titanium-based catalytic material is mixed with MgH2, ball milled, and MgH2 & multivalent titanium composite hydrogen storage material is obtained. The present application can reduce the energy barrier of hydrogen absorption and desorption reactions of hydrogen storage materials, increase the hydrogen absorption / desorption rate, and facilitate large-scale production and application of hydrogen storage materials.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen storage materials, and in particular to a MgH2 & multivalent titanium composite hydrogen storage material and a large-scale preparation method thereof. Background Art

[0002] Hydrogen energy is expected to become the "ideal fuel" in the era of decarbonization, and the discovery, development and modification of high-performance hydrogen storage materials are the key to the future development of solid-state hydrogen storage and hydrogen energy utilization. Among them, magnesium-based hydrogen storage materials represented by MgH2 have many significant advantages. First, the low-cost Mg is extremely abundant in nature and easy to obtain. Secondly, MgH2 has a high reversible hydrogen absorption and desorption capacity of 7.6wt% and a hydrogen absorption capacity of 110kgH2 / m 3 High volumetric hydrogen storage density. Compared with other hydrogen storage methods, the volume of magnesium-based hydrogen storage materials is relatively small when storing the same mass of hydrogen, and has great application prospects.

[0003] However, the thermodynamics of MgH2 is very stable, with a hydrogen desorption enthalpy ΔH of up to 75 kJ / molH2 and an entropy ΔS of 135 J / K / mol. This requires MgH2 to be above 280°C under 0.1 MPa conditions to release hydrogen. On the other hand, the interaction between the HH bond and the Mg-H bond is strong, which makes the hydrogen desorption energy barrier of MgH2 as high as 145.08 kJ / mol, and the hydrogen absorption and desorption rate is slow. Therefore, MgH2 is difficult to directly produce and apply on a large scale as a solid-state hydrogen storage material. MgH2 needs to be modified to reduce the energy barrier of the MgH2 hydrogen absorption and desorption reaction, accelerate its kinetics, and achieve a significant enhancement of hydrogen storage performance while retaining the capacity to the maximum extent. Summary of the Invention

[0004] In order to reduce the energy barrier of hydrogen absorption and desorption reactions of magnesium-based hydrogen storage materials and realize large-scale production and application of magnesium-based hydrogen storage materials, the present application provides a MgH2&multivalent titanium composite hydrogen storage material and a large-scale preparation method.

[0005] In the first aspect, the present application provides a MgH2 & multivalent titanium composite hydrogen storage material, which adopts the following technical solution:

[0006] A MgH2 & multivalent titanium composite hydrogen storage material comprises the following raw materials in weight percentage: 3-7% of a titanium-based catalytic material and 93-97% of MgH2, wherein the titanium-based catalytic material comprises magnesium powder and nano-rutile phase titanium dioxide particles in a mass ratio of 1:(0.9-1.2).

[0007] By adopting the above technical solution, the nano-rutile phase titanium dioxide particles in the titanium-based catalytic material have good catalytic activity and high specific surface area, which can provide abundant active sites, increase the contact area between the titanium-based catalytic material and MgH2, and effectively promote the adsorption and dissociation of hydrogen molecules, thereby reducing the activation energy of the reaction and making the hydrogen absorption and desorption reaction easier to proceed. There is a synergistic effect between the magnesium powder and the nano-rutile phase titanium dioxide particles. The magnesium powder changes the electronic state of the surface of the titanium dioxide particles, so that the titanium-based catalytic material contains Ti in multiple valence states, thereby enhancing the activity of the titanium-based catalytic material. The above raw material ratio helps the titanium-based catalytic material to be evenly dispersed in MgH2, thereby forming an effective catalytic network in the MgH2 matrix, which not only accelerates the hydrogen absorption and desorption reaction, but also makes the reaction more uniform and efficient. Moreover, the amount of titanium-based catalytic material can be reduced while ensuring the catalytic effect, which helps to reduce the production cost of hydrogen storage materials. Therefore, the MgH2&multivalent titanium composite hydrogen storage material formed by titanium-based catalytic materials and MgH2 reduces the energy barrier of hydrogen absorption and desorption reactions, improves the kinetic performance, and helps to increase the hydrogen absorption / desorption rate, thereby realizing the large-scale production and application of magnesium-based hydrogen storage materials.

[0008] In a specific embodiment, the average particle size of the nano-rutile titanium dioxide particles is 50-70 nm.

[0009] By employing this technical solution, nano-rutile titanium dioxide particles in the 50-70nm particle size range possess a high specific surface area, increasing their contact area with MgH2. Furthermore, the nano-sized particles facilitate the adsorption and dissociation of hydrogen molecules, accelerating the kinetics of the hydrogen absorption and desorption reactions. This particle size also facilitates uniform particle distribution within the composite material, further optimizing hydrogen storage performance.

[0010] In a second aspect, the present application provides a large-scale preparation method of a MgH2 & multivalent titanium composite hydrogen storage material, which adopts the following technical solution:

[0011] A large-scale preparation method of a MgH2 & multivalent titanium composite hydrogen storage material comprises the following steps:

[0012] In an argon atmosphere of 9.5-10.5 Pa, magnesium powder is heated to 680-750°C for melting to obtain magnesium water;

[0013] Mixing magnesium water and nano-rutile titanium dioxide particles, heating to 1300° C., and reacting for 60-120 minutes to obtain a reaction solution;

[0014] Cooling the reaction solution to room temperature to obtain a titanium-based catalytic material;

[0015] The titanium-based catalytic material is mixed with MgH2 and subjected to ball milling treatment to obtain a MgH2 & multivalent titanium composite hydrogen storage material.

[0016] By employing this technical solution, at a high temperature of 1300°C, magnesium water promotes a phase transformation of titanium dioxide within the nano-rutile titanium dioxide particles, forming a more catalytically active phase. Simultaneously, during the high-temperature reaction, magnesium powder undergoes electron transfer or chemical bonding with the titanium dioxide, generating a titanium-based catalytic material containing Ti in multiple valence states. Ball milling of the titanium-based catalytic material and MgH2 achieves uniform microscopic dispersion of the two. This dispersion not only enhances the interfacial contact between the titanium-based catalytic material and MgH2 but also optimizes the mass transfer pathway during hydrogen storage, enabling more efficient interaction of hydrogen molecules with the catalytic sites. Consequently, the MgH2 and multivalent titanium composite hydrogen storage material produced using this method exhibits lower energy barriers for hydrogen absorption and desorption reactions and higher absorption and desorption rates, making it suitable for large-scale production and application.

[0017] In a specific embodiment, the nano-rutile titanium dioxide particles are prepared according to the following steps:

[0018] Mixing a TiCl3 ethanol solution having a mass concentration of 15% with water in a volume ratio of 1:(4-6) to obtain a mixed solution;

[0019] The mixed solution is reacted at 120-150° C. with stirring for 40-55 hours, and then centrifuged, washed, and dried to obtain nano-rutile phase titanium dioxide particles.

[0020] By adopting the above technical solution and adjusting the volume ratio of TiCl3 ethanol solution to water and the reaction conditions to the above range, the particle size of the titanium dioxide particles can be adjusted to the nanometer level and have a rutile phase structure. This structure has high catalytic activity and stability, and can effectively improve the performance of hydrogen storage materials. Through steps such as centrifugation, washing, and drying, impurities and unreacted products on the surface of the particles can be removed to ensure the purity and dispersibility of the particles. Using this preparation method, large-scale production of nano-rutile phase titanium dioxide particles can also be achieved, providing strong support for the large-scale application of MgH2 & multivalent titanium composite hydrogen storage materials.

[0021] In a specific embodiment, polystyrene microspheres are added to the mixed solution, and then the mixture is reacted at 120-150°C with stirring for 40-55 hours, centrifuged, washed, and dried. The dried product is calcined at 500-600°C for 3-5 hours to obtain nano-rutile phase titanium dioxide particles with a porous structure.

[0022] By adopting the above technical solution, polystyrene microspheres have a specific pore size and structure. During the reaction process, they are mixed in the product and, after calcination at 500-600°C, the polystyrene microspheres are removed, thereby introducing a porous structure into the nano-rutile phase titanium dioxide particles. The nano-rutile phase titanium dioxide particles with a porous structure have a higher specific surface area, which helps to provide more active sites, allowing the titanium-based catalytic material to more fully contact and react with hydrogen molecules, thereby enhancing the catalytic efficiency of the titanium-based catalytic material and making the hydrogen absorption and desorption reactions faster and more efficient. Moreover, the porous structure is conducive to the diffusion and transmission of hydrogen. During the hydrogen storage process, hydrogen needs to enter and leave the material quickly. The porous structure provides more channels and larger space for hydrogen, thereby accelerating the diffusion rate of hydrogen and increasing the rate of hydrogen storage and desorption.

[0023] In a specific embodiment, magnesium water and nano-rutile phase titanium dioxide particles are mixed, ammonia is introduced, the temperature is raised to 1300°C, and the reaction is carried out for 60-120 minutes to obtain a reaction liquid; while the ammonia is continued to be introduced into the reaction liquid, the reaction liquid is cooled to room temperature to obtain a titanium-based catalytic material with a porous structure.

[0024] By adopting this technical solution, introducing ammonia and reacting at high temperatures causes it to decompose, which helps form a porous structure within the titanium-based catalytic material. This porous structure not only increases the material's specific surface area but also provides more channels and space for hydrogen adsorption and desorption, thereby accelerating the hydrogen storage and release process.

[0025] In a specific embodiment, the ball milling speed of the ball milling treatment is 350-400 rpm and the ball milling time is 7-9 h.

[0026] By adopting the above technical solution, the appropriate ball milling speed and time can ensure that the materials are fully ground and mixed, so that the MgH2 and multivalent titanium can be more evenly dispersed in the composite material. This uniform dispersion is conducive to improving the hydrogen absorption and desorption properties of the hydrogen storage material, making it more efficient and stable. By controlling the ball milling speed and time within the above range, the present application can avoid material structural damage or performance degradation caused by excessive grinding, maintain the integrity and stability of the material, and optimize its hydrogen storage performance.

[0027] In summary, this application has the following beneficial effects:

[0028] 1. The MgH2 & multivalent titanium composite hydrogen storage material prepared in this application has a lower hydrogen absorption and desorption reaction energy barrier and a higher hydrogen absorption / desorption rate, and is convenient for large-scale production and application.

[0029] 2. In this application, nano-rutile titanium dioxide particles with an average particle size of 50-70 nm are preferably used, which can increase the contact area with MgH2, facilitate the adsorption and dissociation of hydrogen molecules, and accelerate the kinetic process of hydrogen absorption and desorption reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the XRD spectrum of the nano-rutile phase titanium dioxide particles prepared in Example 1.

[0031] Figure 2 This is the XRD diffraction pattern of the titanium-based catalytic material prepared in Example 1.

[0032] Figure 3 3 is a graph showing the dehydrogenation amount (wt %) of the composite hydrogen storage materials prepared in Example 1 and Comparative Examples 1-2 within the range of 100-500°C.

[0033] Figure 4 3 is a graph showing the hydrogen absorption amount (wt %) of the composite hydrogen storage material prepared in Example 1 at 140° C., 180° C. and 200° C. within the range of 0-12 min.

[0034] Figure 5 3 is a graph showing the hydrogen release amount (wt %) of the composite hydrogen storage material prepared in Example 1 at 220° C., 270° C. and 300° C. within the range of 0-100 min. DETAILED DESCRIPTION

[0035] The following is combined with Figure 1-5 , Examples and Comparative Examples further illustrate this application in detail.

[0036] Example

[0037] Example 1

[0038] This embodiment provides a MgH2 & multivalent titanium composite hydrogen storage material comprising the following raw materials in weight percentage: 5% titanium-based catalytic material and 95% MgH2. The titanium-based catalytic material comprises magnesium powder and nano-rutile titanium dioxide particles in a 1:1 mass ratio. The nano-rutile titanium dioxide particles have an average particle size of 60 nm.

[0039] This embodiment also provides a large-scale preparation method of MgH2 & multivalent titanium composite hydrogen storage material, comprising the following steps:

[0040] A 15% TiCl₃ ethanol solution was mixed with water in a volume ratio of 1:5 to obtain a mixed solution. The mixed solution was heated to 135°C and maintained at this temperature with stirring for 48 hours, followed by natural cooling to room temperature. The product was centrifuged, washed with ultrapure water, dried at 80°C for 2 hours, and sieved to obtain nano-rutile titanium dioxide particles with an average particle size of 60 nm.

[0041] Magnesium powder is put into a crucible in a medium frequency induction melting furnace, filled with 0.5MPa argon gas, and the air in the medium frequency induction melting furnace is removed. Then the medium frequency induction melting furnace is vacuumed to 10pa, and the crucible is heated to 700℃. The magnesium powder in the crucible is completely melted to obtain magnesium water.

[0042] Nano-rutile titanium dioxide particles were added into the crucible using a secondary feeding device according to the proportion, and the magnesium water and the nano-rutile titanium dioxide particles were mixed. The temperature was then raised to 1300° C. and the mixture was reacted for 90 minutes to obtain a reaction solution.

[0043] The reaction solution was poured onto a water cooling plate and cooled to room temperature to obtain a titanium-based catalytic material.

[0044] The titanium-based catalytic material and MgH2 were mixed in proportion and ball-milled at a ball-milling speed of 380 rpm and a ball-milling time of 8 h to obtain a MgH2 & multivalent titanium composite hydrogen storage material.

[0045] Example 2

[0046] The only difference between this embodiment and embodiment 1 is that the MgH2 & multivalent titanium composite hydrogen storage material includes the following raw materials in weight percentage: 3% titanium-based catalytic material and 97% MgH2.

[0047] Example 3

[0048] The only difference between this embodiment and embodiment 1 is that the MgH2 & multivalent titanium composite hydrogen storage material includes the following raw materials in weight percentage: 7% titanium-based catalytic material and 93% MgH2.

[0049] Example 4

[0050] The only difference between this embodiment and embodiment 1 is that the titanium-based catalytic material includes magnesium powder and nano-rutile phase titanium dioxide particles in a mass ratio of 1:0.9.

[0051] Example 5

[0052] The only difference between this embodiment and embodiment 1 is that the titanium-based catalytic material includes magnesium powder and nano-rutile phase titanium dioxide particles in a mass ratio of 1:1.2.

[0053] Example 6

[0054] The only difference between this embodiment and embodiment 1 is that the average particle size of the nano-rutile phase titanium dioxide particles is 50 nm. In the large-scale preparation method of the MgH2 & multivalent titanium composite hydrogen storage material, nano-rutile phase titanium dioxide particles with an average particle size of 50 nm are obtained by sieving.

[0055] Example 7

[0056] The only difference between this embodiment and embodiment 1 is that the average particle size of the nano-rutile phase titanium dioxide particles is 70 nm. In the large-scale preparation method of the MgH2 & multivalent titanium composite hydrogen storage material, nano-rutile phase titanium dioxide particles with an average particle size of 70 nm are obtained by sieving.

[0057] Example 8

[0058] This example differs from Example 1 only in that, in the large-scale preparation method of the MgH2 & multivalent titanium composite hydrogen storage material, a 15% TiCl3 ethanol solution is mixed with water in a volume ratio of 1:4 to form a mixed solution. The mixed solution is heated to 150°C, maintained at this temperature with stirring, and reacted for 40 hours, followed by natural cooling to room temperature.

[0059] Example 9

[0060] This example differs from Example 1 only in that, in the large-scale preparation method of the MgH2 & multivalent titanium composite hydrogen storage material, a 15% TiCl3 ethanol solution is mixed with water in a volume ratio of 1:6 to form a mixed solution. The mixed solution is heated to 120°C, maintained at this temperature and stirred for 55 hours, and then naturally cooled to room temperature.

[0061] Example 10

[0062] This embodiment differs from Example 1 only in that, in the large-scale preparation method of the MgH2 & multivalent titanium composite hydrogen storage material, a 15% TiCl3 ethanol solution is mixed with water in a volume ratio of 1:5 to obtain a mixed solution. Polystyrene microspheres are added to the mixed solution at a mass ratio of 3:100. The mixed solution is then heated to 135°C, maintained at this temperature and stirred for 48 hours, and then naturally cooled to room temperature. The product is centrifuged, washed with ultrapure water, and then dried at 80°C for 2 hours. The dried product is then placed in a muffle furnace, heated to 550°C, and calcined at this temperature for 4 hours. After naturally cooling to room temperature, the calcined product is sieved to obtain nano-rutile titanium dioxide particles with an average particle size of 60 nm and a porous structure.

[0063] Example 11

[0064] The only difference between this embodiment and embodiment 10 is that in the large-scale preparation method of MgH2 & multivalent titanium composite hydrogen storage material, the dried product is placed in a muffle furnace, heated to 500°C, and then calcined at this temperature for 5 hours.

[0065] Example 12

[0066] The only difference between this embodiment and embodiment 10 is that in the large-scale preparation method of MgH2 & multivalent titanium composite hydrogen storage material, the dried product is placed in a muffle furnace, heated to 600°C, and then calcined at this temperature for 3 hours.

[0067] Example 13

[0068] This Example differs from Example 1 only in that, in the large-scale preparation method of the MgH2 & multivalent titanium composite hydrogen storage material, nano-rutile titanium dioxide particles are added proportionally to a crucible using a secondary feeding device, the magnesium water and the nano-rutile titanium dioxide particles are mixed, and simultaneously, ammonia gas is introduced into the medium-frequency induction melting furnace, the argon gas in the medium-frequency induction melting furnace is removed, and the medium-frequency induction melting furnace is evacuated to 10 Pa. The temperature is then raised to 1300°C, and the reaction is carried out for 90 minutes to obtain a reaction solution. The reaction solution is poured onto a water-cooled plate and cooled to room temperature while the ammonia gas is continued to flow into the reaction solution, thereby obtaining a titanium-based catalytic material having a porous structure.

[0069] Example 14

[0070] The only difference between this embodiment and Example 1 is that in the large-scale preparation method of MgH2 & multivalent titanium composite hydrogen storage material, the titanium-based catalytic material and MgH2 are mixed in proportion and ball-milled at a ball milling speed of 350 rpm and a ball milling time of 9 hours to obtain the MgH2 & multivalent titanium composite hydrogen storage material.

[0071] Example 15

[0072] The only difference between this embodiment and Example 1 is that in the large-scale preparation method of MgH2 & multivalent titanium composite hydrogen storage material, the titanium-based catalytic material and MgH2 are mixed in proportion and ball-milled at a ball milling speed of 350 rpm and a ball milling time of 9 hours to obtain the MgH2 & multivalent titanium composite hydrogen storage material.

[0073] Comparative Example

[0074] Comparative Example 1

[0075] This comparative example differs from Example 1 only in that the composite hydrogen storage material in this comparative example comprises the following raw materials in weight percentage: 5% nano-rutile titanium dioxide particles and 95% MgH2. In the large-scale preparation method of the composite hydrogen storage material, an equal amount of nano-rutile titanium dioxide particles replaces the titanium-based catalytic material.

[0076] Comparative Example 2

[0077] The only difference between this comparative example and Example 1 is that the composite hydrogen storage material of this comparative example comprises the following raw materials in weight percentage: 100% MgH2. In the large-scale preparation method of the composite hydrogen storage material, an equal amount of MgH2 is used to replace the titanium-based catalytic material.

[0078] Performance testing

[0079] The following performance tests were performed on the composite hydrogen storage materials prepared in Examples 1-15 and Comparative Examples 1-2:

[0080] The nano-rutile titanium dioxide particles and titanium-based catalytic materials prepared in Example 1 were tested using a TD-3500 X-ray diffractometer. Figure 1 and Figure 2 shown.

[0081] The dehydrogenation amount (wt%) of the composite hydrogen storage materials prepared in Example 1 and Comparative Examples 1-2 was tested in the range of 100-500°C. The data curves are shown in FIG. Figure 3 shown.

[0082] The hydrogen absorption (wt%) of the composite hydrogen storage material prepared in Example 1 was tested at 140°C, 180°C and 200°C within the range of 0-12 min. The data curves are shown in FIG. Figure 4 shown.

[0083] The hydrogen release amount (wt%) of the composite hydrogen storage material prepared in Example 1 was tested at 220°C, 270°C and 300°C within the range of 0-100 min. The data curves are shown in FIG. Figure 5 shown.

[0084] The hydrogen absorption amount of the composite hydrogen storage materials prepared in Examples 1-15 and Comparative Examples 1-2 in the 10th minute at 140°C and the hydrogen release amount in the 100th minute at 300°C (wt %) are shown in Table 1.

[0085] Table 1

[0086]

[0087] Combined with Example 1 and Figure 1-2 It can be seen that the preparation method of Example 1 obtains rutile-phase nano-titanium dioxide particles and titanium-based catalytic materials containing Ti in various valence states.

[0088] Combined with Example 1 and Comparative Examples 1-2 and Figure 3It can be seen that compared to Example 1, within 350°C, the absolute values ​​of the dehydrogenation amounts in Comparative Examples 1-2 within the range of 100-500°C are all smaller. At temperatures above 400°C, the absolute values ​​of the dehydrogenation amounts in Comparative Examples 1-2 within the range of 100-500°C are all larger. This demonstrates that the raw material ratio and preparation method of Example 1 help reduce the activation energy of the hydrogen storage material reaction and the energy barrier for the hydrogen absorption and desorption reactions.

[0089] From Example 1 and Comparative Examples 1-2 and Table 1, it can be seen that compared with Example 1, the absolute value of the hydrogen absorption amount of the composite hydrogen storage material of Comparative Examples 1-2 at 140°C in the 10th minute and the absolute value of the hydrogen release amount at 300°C in the 100th minute are smaller, which shows that the raw material ratio and preparation method of Example 1 are helpful to improve the hydrogen absorption / desorption rate of the hydrogen storage material.

[0090] Combined with Example 1 and Figure 4-5 It can be seen that the composite hydrogen storage material prepared by the raw material ratio and preparation method of Example 1 has the fastest hydrogen absorption rate and the highest absolute value of hydrogen absorption at 140°C; and the fastest hydrogen release rate and the highest absolute value of hydrogen release at 300°C.

[0091] Combining Examples 1-15 and Comparative Examples 1-2 with Table 1, it can be seen that the composite hydrogen storage materials of Examples 1-15 have large hydrogen absorption amounts in the 10th minute at 140°C and hydrogen release amounts in the 100th minute at 300°C, and are significantly greater than those of Comparative Examples 1-2. Furthermore, the detection values ​​of Examples 10-13 are significantly greater than those of Example 1. This demonstrates that the raw material ratios and preparation methods of Examples 1-15 can produce composite hydrogen storage materials with low hydrogen absorption and desorption reaction energy barriers and fast hydrogen absorption / desorption rates. Furthermore, the composite hydrogen storage materials produced using the preparation methods of Examples 10-13 exhibit superior performance.

[0092] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A large-scale preparation method of MgH2 & multivalent titanium composite hydrogen storage material, characterized in that: The steps include: The MgH2 & multivalent titanium composite hydrogen storage material comprises the following raw materials in weight percentage: 3-7% titanium-based catalytic material and 93-97% MgH2, wherein the titanium-based catalytic material comprises magnesium powder and nano-rutile phase titanium dioxide particles in a mass ratio of 1:(0.9-1.2); the nano-rutile phase titanium dioxide particles have an average particle size of 50-70 nm; In an argon atmosphere of 9.5-10.5 Pa, magnesium powder is heated to 680-750°C for melting to obtain magnesium water; Mix magnesium water and nano-rutile titanium dioxide particles, introduce ammonia gas, heat to 1300°C, and react for 60-120 minutes to obtain a reaction solution; The reaction liquid is cooled to room temperature while ammonia gas is continuously introduced into the reaction liquid to obtain a titanium-based catalytic material having a porous structure; The titanium-based catalytic material is mixed with MgH2 and subjected to ball milling to obtain a MgH2 & multivalent titanium composite hydrogen storage material; The nano-rutile phase titanium dioxide particles are prepared according to the following steps: Mixing a TiCl3 ethanol solution having a mass concentration of 15% with water in a volume ratio of 1:(4-6) to obtain a mixed solution; Polystyrene microspheres are added to the mixed solution, and then reacted at 120-150° C. with stirring for 40-55 hours, centrifuged, washed, and dried. The dried product is calcined at 500-600° C. for 3-5 hours to obtain nano-rutile phase titanium dioxide particles with a porous structure.

2. The large-scale preparation method of a MgH2 & multivalent titanium composite hydrogen storage material according to claim 1, characterized in that: The ball milling speed of the ball milling treatment is 350-400 rpm and the ball milling time is 7-9 hours.

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