UiO-66 regulation-based magnesium-based composite hydrogen storage material, and preparation method and application thereof

Abstract

This invention relates to a magnesium-based composite hydrogen storage material regulated by UiO-66, its preparation method, and its application. The high-performance magnesium-based composite hydrogen storage material provided comprises MgH2 and UiO-66, wherein MgH2 powder is the main phase, and UiO-66 is a high-temperature resistant metal-organic framework (MOF) composed of Zr, O, and C, possessing a large specific surface area and ultra-high structural stability, and plays a catalytic role. It is synthesized by hydrothermal and calcination methods. Compared with existing technologies, the magnesium-based composite hydrogen storage material provided by this invention has a dehydrogenation temperature range of 180 ℃–271 ℃ and a dehydrogenation activation energy as low as 69.26 kJ / mol. ‑1 It also possesses rapid room-temperature hydrogen absorption capacity and excellent circulating hydrogen storage performance, which is of great significance for promoting the application of MgH2 and improving its hydrogen storage performance.

Description

Technical Field

[0001] This invention belongs to the field of magnesium-based solid hydrogen storage materials technology, and relates to a magnesium-based composite hydrogen storage material based on UiO-66 regulation, its preparation method and application. Background Technology

[0002] With the depletion of fossil fuels and the increasing severity of environmental problems, the development of clean, efficient, and sustainable new energy sources has become a global focus. Hydrogen energy, due to its high energy density and clean, pollution-free nature, is considered one of the most promising secondary energy sources. However, achieving safe and efficient hydrogen storage still faces numerous technical challenges, which have become a significant factor limiting the large-scale application of hydrogen energy. Among various hydrogen storage technologies, solid-state hydrogen storage has become a research hotspot in recent years due to its high safety factor, large volumetric hydrogen storage density, and ease of integration.

[0003] Currently, solid-state hydrogen storage materials mainly include metal hydrides, hydrogen storage alloys, and porous adsorbent materials. Among them, metal hydrides have attracted widespread attention due to their high theoretical hydrogen storage capacity and excellent reversible hydrogen storage performance. Magnesium-based hydrogen storage materials, especially magnesium hydride, have advantages such as abundant resources, low cost, high theoretical hydrogen storage density (7.6 wt%), and good reversibility, and are expected to become one of the most promising solid-state hydrogen storage materials. However, magnesium-based hydrogen storage materials still face challenges such as slow hydrogen storage kinetics and high dehydrogenation temperatures, which severely limit their large-scale application.

[0004] In recent years, metal-organic frameworks (MOFs) have shown promising application prospects in energy storage and catalysis due to their large specific surface area, regular pore structure, and strong designability. For example, Chinese patent CN110526208B provides a method for preparing magnesium-based composite hydrogen storage materials based on MOF nanoconfined structures. This method involves preparing MOFs and magnesium-based composite hydrogen storage materials, including reacting a metal inorganic salt with trimesic acid in N,N-dimethylformamide to form MOFs, followed by heating under vacuum, stirring with a dibutylmagnesium hexane solution, removing the solvent, hydrogenating, and releasing hydrogen to obtain MgH2 hydrogen storage material. However, the hydrogen storage capacity, storage temperature, and dehydrogenation kinetics of this material require further improvement. Summary of the Invention

[0005] The purpose of this invention is to provide a magnesium-based composite hydrogen storage material based on UiO-66 regulation, its preparation method and application, which has lower hydrogen absorption / desorption temperature, faster kinetic performance and excellent cycle stability.

[0006] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a magnesium-based composite hydrogen storage material regulated by UiO-66, obtained by mechanical ball milling of MgH2 powder and UiO-66 powder. The composition is MgH2-x wt% UiO-66, wherein MgH2 powder is the main phase, and UiO-66 is a high-temperature resistant metal-organic framework (MOF) with ultra-large specific surface area and ultra-high structural stability, which plays a catalytic role. It is synthesized by hydrothermal and calcination methods.

[0007] Furthermore, the mass content of MgH2 powder is 5~20%, i.e., x=5~20.

[0008] Furthermore, the UiO-66 powder is prepared through the following steps: S1. Dissolve ZrCl4 powder in acetic acid and stir until completely dissolved to obtain a ZrCl4 solution; S2. Dissolve terephthalic acid in DMF and stir until completely dissolved to obtain a BDC solution; S3. Slowly add the ZrCl4 solution in S1 to the BDC solution in S2 while stirring until the mixture is homogeneous to obtain the precursor solution. S4. Add sodium hydroxide solution dropwise to the precursor solution in S3 until the pH value is between 5 and 6 to obtain the reaction solution; S5. Transfer the reaction solution from S4 to a reaction vessel, heat the reaction, and after centrifugation, washing, and vacuum drying, obtain UiO-66 powder.

[0009] Furthermore, in S3, the addition amounts of ZrCl4 solution and BDC solution satisfy the following: the mass ratio of ZrCl4 powder to terephthalic acid is (40~60):20.

[0010] Furthermore, in S4, the concentration of the sodium hydroxide solution used is 1~1.5 mol / L.

[0011] Furthermore, in S5, the heating reaction temperature is 110~130℃, and the time is 22~26h. Preferably, the reaction temperature is 120℃ and the reaction time is 22~26h.

[0012] In a second aspect, the present invention provides a method for preparing a magnesium-based composite hydrogen storage material based on UiO-66 regulation. The method involves mixing UiO-66 powder with MgH2 powder and then transferring the mixture to a ball mill jar for ball milling to obtain the magnesium-based composite hydrogen storage material.

[0013] Furthermore, during the ball milling process, the ball-to-material ratio is controlled at 55~65:1, the ball milling speed is 400~600 rpm, and the time is 8~12 h.

[0014] In a third aspect, the present invention provides an application of a magnesium-based composite hydrogen storage material based on UiO-66 regulation in energy systems including distributed energy and hydrogen power plants.

[0015] Compared with the prior art, the present invention has the following advantages: (1) The high-performance MgH2-x wt% UiO-66 (x = 5, 7.5, 10, 12.5, 40) magnesium-based composite hydrogen storage materials prepared have lower absorption / desorption temperatures, faster kinetic performance and excellent cycle stability.

[0016] (2) The raw materials required for the metal-organic framework UiO-66 are inexpensive and the preparation process is simple. (3) The metal-organic framework UiO-66 has good thermal stability, large specific surface area and abundant pores, and has long-term stable catalytic effect that is superior to most conventional metal-organic framework materials. Attached Figure Description

[0017] Figure 1 The temperature programmed desorption (TPD) curves of the MgH2+x wt% UiO-66 composite hydrogen storage material in Example 1 of this invention and the corresponding comparative sample are shown.

[0018] Figure 2 The temperature-programmed adsorption (TPA) curves of the MgH2+10 wt% UiO-66 composite hydrogen storage material in Example 1 of this invention and the corresponding comparative sample are shown.

[0019] Figure 3 The isothermal dehydrogenation kinetic curves of the MgH2+10 wt% UiO-66 composite hydrogen storage material prepared in Example 1 at 250 ℃, 275 ℃, 300 ℃, and 325 ℃ are shown.

[0020] Figure 4 The activation energy curves of the dehydrogenation reaction of the MgH2+10 wt% UiO-66 composite material prepared in Example 1 at 250 ℃, 275 ℃, 300 ℃, and 325 ℃ are shown.

[0021] Figure 5 The XRD patterns of the UiO-66 MOF catalyst and MgH2+10 wt% UiO-66 composite material prepared in Example 1 after ball milling, dehydrogenation, and rehydrogen absorption are shown.

[0022] Figure 6 The image shows the specific surface area (BET) test results of the UiO-66 MOF catalyst prepared in Example 1. In the image, (a) is the nitrogen adsorption-desorption isotherm of the UiO-66 MOF catalyst, and (b) is the pore size distribution curve of the UiO-66 MOF catalyst.

[0023] Figure 7 The image shown is a TEM image of the UiO-66 MOF catalyst prepared in Example 1, with the embedded image being the particle size distribution of the MOF material. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0025] In the following embodiments, the terephthalic acid (BDC) powder, zirconium tetrachloride (ZrCl4) powder, sodium hydroxide powder, and DMF solution used were purchased from Titan Technology Exploration Platform; acetic acid and magnesium hydride powder (MgH2, purity 99.9%) were commercially available products in the field.

[0026] Example 1 This embodiment provides a method for preparing a high-performance MgH2+10 wt% UiO-66 magnesium-based composite hydrogen storage material. The specific steps are as follows: (1) Dissolve 40 mg ZrCl4 in 3.5 ml acetic acid to obtain zirconium tetrachloride solution for later use; (2) Dissolve 23 mg of terephthalic acid in 30 ml of DMF solution to obtain a ligand solution for later use; (3) Slowly add zirconium tetrachloride solution to ligand solution and react for 2 h under strong stirring to obtain mixed solution for later use.

[0027] (4) Add small amounts of 1 mol / L NaOH solution dropwise to the mixed solution until the pH value of the solution is between 5 and 6, and then prepare the reaction solution for later use.

[0028] (5) Place the reaction solution in a vacuum oven and maintain it in a vacuum environment of 120 °C for 24 h.

[0029] (6) Centrifuge and wash the sample obtained in step (5) multiple times with DMF and deionized water until the supernatant is neutral, and set aside for later use.

[0030] (7) Filter the sample obtained in step (6) to remove excess water, and retain the precipitate for later use.

[0031] (8) The precipitate obtained in step (7) is dried at 60 °C for 12 h to obtain dried UiO-66 catalyst powder. The catalyst is recovered and used for later use.

[0032] (9) Weigh 450 mg of MgH2 powder and 50 mg of UiO-66 catalyst powder obtained in step (8) and place them in a 100 ml ball mill jar. Control the ball-to-material ratio to be 60:1 and ball mill at 500 rpm for 10 h. The desired high-performance MgH2-10wt% UiO-66 magnesium-based composite hydrogen storage material is thus obtained.

[0033] Example 2 (1) Dissolve 40 mg ZrCl4 in 3.5 ml acetic acid to obtain zirconium tetrachloride solution for later use; (2) Dissolve 23 mg of terephthalic acid in 30 ml of DMF solution to obtain a ligand solution for later use; (3) Slowly add zirconium tetrachloride solution to ligand solution and react for 2 h under strong stirring to obtain mixed solution for later use.

[0034] (4) Add small amounts of 1 mol / L NaOH solution dropwise to the mixed solution until the pH value of the solution is between 5 and 6, and then prepare the reaction solution for later use.

[0035] (5) Place the reaction solution in a vacuum oven and maintain it in a vacuum environment at 120 °C for 24 h. (6) Centrifuge and wash the sample obtained in step (5) multiple times with DMF and deionized water until the supernatant is neutral, and set aside for later use.

[0036] (7) Filter the sample obtained in step (6) to remove excess water, and retain the precipitate for later use.

[0037] (8) The precipitate obtained in step (7) is dried at 60 °C for 12 h to obtain dried UiO-66 catalyst powder. The catalyst is recovered and used for later use.

[0038] (9) Weigh 475 mg of MgH2 powder and 25 mg of UiO-66 catalyst powder obtained in step (8) and place them in a 100 ml ball mill jar. Control the ball-to-material ratio to be 60:1 and ball mill at 500 rpm for 10 h. The desired high-performance MgH2-5wt% UiO-66 magnesium-based composite hydrogen storage material is thus obtained.

[0039] Example 3 (1) Dissolve 40 mg ZrCl4 in 3.5 ml acetic acid to obtain zirconium tetrachloride solution for later use; (2) Dissolve 23 mg of terephthalic acid in 30 ml of DMF solution to obtain a ligand solution for later use; (3) Slowly add zirconium tetrachloride solution to ligand solution and react for 2 h under strong stirring to obtain mixed solution for later use.

[0040] (4) Add small amounts of 1 mol / L NaOH solution dropwise to the mixed solution until the pH value of the solution is between 5 and 6, and then prepare the reaction solution for later use.

[0041] (5) Place the reaction solution in a vacuum oven and maintain it in a vacuum environment at 120 °C for 24 h. (6) Centrifuge and wash the sample obtained in step (5) multiple times with DMF and deionized water until the supernatant is neutral, and set aside for later use.

[0042] (7) Filter the sample obtained in step (6) to remove excess water, and retain the precipitate for later use.

[0043] (8) The precipitate obtained in step (7) is dried at 60 °C for 12 h to obtain dried UiO-66 catalyst powder. The catalyst is recovered and used for later use.

[0044] (9) Weigh 462.5 mg of MgH2 powder and 37.5 mg of UiO-66 catalyst powder obtained in step (8) and place them in a 100 ml ball mill jar. Control the ball-to-material ratio to be 60:1 and ball mill at 500 rpm for 10 h. The desired high-performance MgH2-7.5 wt% UiO-66 magnesium-based composite hydrogen storage material is thus obtained.

[0045] Example 4 (1) Dissolve 40 mg ZrCl4 in 3.5 ml acetic acid to obtain zirconium tetrachloride solution for later use; (2) Dissolve 23 mg of terephthalic acid in 30 ml of DMF solution to obtain a ligand solution for later use; (3) Slowly add zirconium tetrachloride solution to ligand solution and react for 2 h under strong stirring to obtain mixed solution for later use.

[0046] (4) Add small amounts of 1 mol / L NaOH solution dropwise to the mixed solution until the pH value of the solution is between 5 and 6, and then prepare the reaction solution for later use.

[0047] (5) Place the reaction solution in a vacuum oven and maintain it in a vacuum environment at 120 °C for 24 h. (6) Centrifuge and wash the sample obtained in step (5) multiple times with DMF and deionized water until the supernatant is neutral, and set aside for later use.

[0048] (7) Filter the sample obtained in step (6) to remove excess water, and retain the precipitate for later use.

[0049] (8) The precipitate obtained in step (7) is dried at 60 °C for 12 h to obtain dried UiO-66 catalyst powder. The catalyst is recovered and used for later use.

[0050] (9) Weigh 437.5 mg of MgH2 powder and 62.5 mg of UiO-66 catalyst powder obtained in step (8) and place them in a 100 ml ball mill jar. Control the ball-to-material ratio to be 60:1 and ball mill at 500 rpm for 10 h. The desired high-performance MgH2-12.5 wt% UiO-66 magnesium-based composite hydrogen storage material is thus obtained.

[0051] Comparative Example 1 450 mg of MgH2 powder and 50 mg of ZrC powder were placed in a 100 ml ball mill jar, and the ball-to-powder ratio was controlled at 60:1. The mixture was ball-milled at 500 rpm for 10 h. The control sample MgH2-10 wt% ZrC composite hydrogen storage material was thus obtained.

[0052] Figure 1 The temperature-programmed desorption (TPD) curves are shown for the MgH2-x wt% UiO-66 composite hydrogen storage materials prepared in Examples 2-4 and the control sample. Figure 1 It can be seen that with the increase of UiO-66 MOF addition, the initial dehydrogenation temperature of the MgH2-x wt% UiO-66 composite hydrogen storage material gradually decreases. Specifically, the initial dehydrogenation temperature of the MgH2-10 wt% UiO-66 composite hydrogen storage material decreases to 180 ℃, the termination dehydrogenation temperature is 271 ℃, and the dehydrogenation capacity is as high as 6.66 wt%. In contrast, the MgH2-10 wt% ZrC composite hydrogen storage material exhibits a higher dehydrogenation temperature range and a lower dehydrogenation capacity. These results indicate that the MgH2-10 wt% UiO-66 composite hydrogen storage material possesses excellent comprehensive performance in terms of dehydrogenation temperature and hydrogen storage capacity.

[0053] Figure 1 and 2The results of temperature-programmed desorption (TPD) and temperature-programmed adsorption (TPA) performance tests for MgH2-10 wt% UiO-66 composite material and MgH2-10 wt% ZrC composite material are provided. The dehydrogenation temperature ranges for the MgH2-10 wt% UiO-66 composite material and the MgH2-10 wt% ZrC control sample are 180 ℃~271 ℃ and 200 ℃~300 ℃, respectively. Both can absorb hydrogen from room temperature, but below 100 ℃, the hydrogen absorption rate of the MgH2-10 wt% UiO-66 composite material is significantly higher than that of the MgH2-10 wt% ZrC control sample. The MgH2-10 wt% UiO-66 composite material can absorb 85% of H2 at 100 ℃, while the MgH2-10 wt% ZrC control sample can only absorb hydrogen slowly at 100 ℃. It is evident that the MgH2-10 wt% UiO-66 composite material outperforms the MgH2-10 wt% ZrC comparative sample in terms of hydrogen absorption / dehydrogenation thermodynamics, kinetics, and hydrogen storage capacity.

[0054] Figure 2 The figure shows the temperature-programmed adsorption (TPA) curves of the high-performance MgH2-10 wt% UiO-66 magnesium-based composite hydrogen storage material prepared in Example 1, and the comparative samples MgH2-10 wt% ZrC and pure MgH2, as follows: Figure 2 As shown, pure MgH2 only begins to significantly absorb hydrogen from 100 °C. In contrast, the MgH2-10 wt% UiO-66 composite hydrogen storage material begins to rapidly absorb hydrogen from room temperature. At 100 °C, it can absorb 86% (5.67 wt%) of H2, and a rapid hydrogen absorption process can be observed. This indicates that the introduction of UiO-66 significantly reduces the initial hydrogen absorption temperature of MgH2 and significantly enhances its kinetic performance. Ultimately, the maximum hydrogen absorption capacity of the MgH2-10 wt% UiO-66 composite hydrogen storage material stabilizes at approximately 6.6 wt%, very close to its theoretical normalized capacity. While the MgH2-10 wt% ZrC composite hydrogen storage material can also begin to absorb hydrogen at room temperature, its rate is significantly between that of the MgH2-10 wt% UiO-66 composite hydrogen storage material and pure MgH2, and it still has not reached its theoretical maximum hydrogen absorption capacity at 300 °C. The above results clearly show that the UiO-66 MOF material, which also contains Zr and C elements, has a more significant effect on enhancing the hydrogen absorption performance of MgH2.

[0055] Figure 3The isothermal dehydrogenation kinetics curves of the high-performance MgH2-10 wt% UiO-66 composite hydrogen storage material prepared in Example 1 are shown at 250 ℃, 275 ℃, 300 ℃, and 325 ℃. With increasing temperature, the dehydrogenation rate significantly increases, and the time required to reach dehydrogenation saturation is also significantly shortened. Notably, even at a low temperature of 250 ℃, the MgH2-10 wt% UiO-66 composite hydrogen storage material can approach dehydrogenation saturation within 10 min, and at temperatures above 275 ℃, complete dehydrogenation can even be achieved within 5 min, with the final dehydrogenation capacity remaining essentially consistent. This indicates that the introduction of UiO-66 can significantly accelerate the dehydrogenation kinetics of MgH2 and improve its thermal stability.

[0056] Figure 4 The high-performance MgH2-10 wt% UiO-66 composite hydrogen storage material prepared in Example 1 is presented based on... Figure 3 JMA dynamic fitting results of relevant data, Figure 4 It can be seen that the apparent activation energy for dehydrogenation of the MgH2-10 wt% UiO-66 composite hydrogen storage material is as low as 69.26 kJ / mol. -1 The lower activation energy indicates that the introduction of UiO-66 effectively lowers the dehydrogenation energy barrier of MgH2, thereby improving its dehydrogenation reaction rate and kinetic performance.

[0057] Figure 5 The XRD characterization results of the high-performance MgH2-10 wt% UiO-66 composite hydrogen storage material prepared in Example 1 after ball milling, dehydrogenation, and rehydrogen absorption are presented. As can be seen from the figures, characteristic diffraction peaks of UiO-66 were detected in the composite hydrogen storage material under all the above different states, and no other impurity phases were formed except for Mg and MgH2. This indicates that the UiO-66 MOF did not undergo a phase transition in the MgH2-10 wt% UiO-66 composite hydrogen storage material, and mainly participated in the reaction as a catalyst, playing a significant catalytic role.

[0058] Figure 6 The specific surface area (BET) test results of the UiO-66 MOF catalyst prepared in Example 1 are presented. (a) shows the nitrogen adsorption-desorption isotherm of the UiO-66 MOF catalyst. As can be seen from the figure, UiO-66 exhibits obvious rapid adsorption characteristics in the low relative pressure region (p / p0<0.1), while the adsorption amount increases significantly in the high relative pressure region. This indicates that the material has both abundant microporous structure and a certain proportion of external surface and mesoporous structure. The specific surface area of ​​UiO-66 is calculated to be 1022.4453 m². 2 / g, of which the microporous specific surface area is 792.2682 m² 2 / g, with a mesoporous specific surface area of ​​230.1771 m². 2 The / g indicates that UiO-66 has a high specific surface area and abundant pore structure. (b) shows the pore size distribution curve of the UiO-66 MOF catalyst. It can be seen that the pore structure of UiO-66 is mainly concentrated in the micropore region, and its micropore volume is as high as 0.321772 cm³. 3 The / g indicates that the material has a relatively concentrated micropore distribution. The high specific surface area and hierarchical porous structure enable UiO-66 to provide numerous active interfaces and diffusion channels during the composite process with MgH2. The abundant micropores act as temporary storage and transport channels for hydrogen molecules in the composite hydrogen storage material, shortening the diffusion path of hydrogen on and within the MgH2 particles and accelerating the hydrogen molecule transport rate in the composite material. This promotes the rapid adsorption and release of hydrogen at the gas-solid interface and between the solid phase during the hydrogen absorption / desorption process, thereby reducing the reaction energy barrier during the absorption / desorption reaction to some extent. Furthermore, the stable framework structure of UiO-66 effectively prevents the aggregation of Mg / MgH2 during hydrogen storage; therefore, the MgH2-10 wt% UiO-66 composite hydrogen storage material exhibits good cycle stability. These results demonstrate that compared to ZrC, which also contains Zr and C elements and has an irregular framework structure, UiO-66 MOF material significantly enhances the overall hydrogen storage performance of MgH2.

[0059] Figure 7 TEM images of the UiO-66 MOF catalyst prepared in Example 1 are provided. It can be seen that the prepared UiO-66 MOF has a regular, highly dispersed octahedral structure. The embedded particle size distribution map shows that the size of the prepared UiO-66 MOF is concentrated between 100-200 nm. This is due to its high particle size distribution of up to 1022.4453 nm. 2 The specific surface area of ​​Mg / g is key to providing a large number of transport channels for H transport during the hydrogen storage process in Mg / MgH2.

[0060] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A magnesium-based composite hydrogen storage material based on UiO-66 regulation, characterized in that, It is obtained by mechanical ball milling and mixing of MgH2 powder and UiO-66 powder.

2. The magnesium-based composite hydrogen storage material based on UiO-66 regulation according to claim 1, characterized in that, The mass content of MgH2 powder is 5-20%.

3. The magnesium-based composite hydrogen storage material based on UiO-66 regulation according to claim 1, characterized in that, The UiO-66 powder is prepared by the following steps: S1. Dissolve ZrCl4 powder in acetic acid and stir until completely dissolved to obtain a ZrCl4 solution; S2. Dissolve terephthalic acid in DMF and stir until completely dissolved to obtain a BDC solution; S3. Slowly add the ZrCl4 solution in S1 to the BDC solution in S2 while stirring until the mixture is homogeneous to obtain the precursor solution. S4. Add sodium hydroxide solution dropwise to the precursor solution in S3 until the pH value is between 5 and 6 to obtain the reaction solution; S5. Transfer the reaction solution from S4 to a reaction vessel, heat the reaction, and after centrifugation, washing, and vacuum drying, obtain UiO-66 powder.

4. The magnesium-based composite hydrogen storage material based on UiO-66 regulation according to claim 3, characterized in that, In S3, the addition amounts of ZrCl4 solution and BDC solution satisfy the following: the mass ratio of ZrCl4 powder to terephthalic acid is (40~60):

20.

5. The magnesium-based composite hydrogen storage material based on UiO-66 regulation according to claim 3, characterized in that, In S4, the concentration of the sodium hydroxide solution used is 1~1.5 mol / L.

6. The magnesium-based composite hydrogen storage material based on UiO-66 regulation according to claim 3, characterized in that, In S5, the heating reaction temperature is 110~130℃ and the time is 22~26h.

7. A method for preparing a magnesium-based composite hydrogen storage material based on UiO-66 regulation as described in any one of claims 1-6, characterized in that, After mixing UiO-66 powder and MgH2 powder, the mixture was transferred to a ball mill jar for ball milling to obtain magnesium-based composite hydrogen storage material.

8. The preparation method of a magnesium-based composite hydrogen storage material based on UiO-66 regulation according to claim 7, characterized in that, During the ball milling process, the ball-to-material ratio is controlled at 55~65:1, the ball milling speed is 400~600 rpm, and the time is 8~12h.

9. The application of a magnesium-based composite hydrogen storage material based on UiO-66 regulation as described in any one of claims 1-6 in energy systems including distributed energy and hydrogen power plants.

Images