Hydrogen storage material, method of making and use thereof and method for storing and releasing hydrogen gas

Abstract

This invention provides hydrogen storage materials, their preparation methods, applications, and methods for storing and releasing hydrogen, relating to the field of hydrogen storage technology. Firstly, this invention provides a hydrogen storage material comprising an absorbent and a catalyst. The absorbent is an aqueous solution containing a first metal ion and a second metal ion. The first metal ion has a redox potential of -0.5V to +0.5V. The second metal ion is a metal ion that can be simultaneously reduced with the first metal ion to form a hydrogen storage alloy. The catalyst is palladium nanoparticles. This invention's hydrogen storage material can efficiently store hydrogen in a safe environment without requiring additional energy, exhibiting high energy efficiency and low cost. Furthermore, this hydrogen storage material is recyclable. Secondly, based on this hydrogen storage material, this invention provides a method for storing and releasing hydrogen. This method can reversibly store and release hydrogen, solving the problems existing in current hydrogen storage and release technologies, and has promising application prospects.

Description

Technical Field

[0001] This invention relates to the field of hydrogen storage technology, specifically to hydrogen storage materials, preparation methods, applications, and methods for storing and releasing hydrogen. Background Technology

[0002] With the continued growth of global energy demand and the increasing prominence of environmental issues, hydrogen energy, as a clean and efficient secondary energy source, has received widespread attention. It possesses significant advantages such as high energy density per unit mass and zero carbon emissions during utilization, and is considered an important component of the future energy system. However, as the scale of hydrogen application expands, storage has become one of the key challenges restricting the development of hydrogen energy. Developing safe, economical, and efficient hydrogen storage technologies is a core prerequisite for realizing a hydrogen circular economy and large-scale application.

[0003] Hydrogen is gaseous at room temperature and pressure, with an extremely low density (approximately 0.09 kg / m³). 3 The low volumetric energy density and difficulty in storing hydrogen constitute the fundamental bottleneck for the practical application of hydrogen energy. Currently, mainstream hydrogen storage methods are primarily based on physical approaches, including high-pressure gaseous hydrogen storage and cryogenic liquid hydrogen storage. High-pressure hydrogen storage technology is relatively mature, but it requires compressing hydrogen to pressures of tens of megapascals, resulting in high energy consumption and safety risks such as hydrogen embrittlement and leakage. While liquid hydrogen storage offers high volumetric hydrogen storage density, the liquefaction process requires extremely low temperatures (approximately 20 K), leading to high energy consumption, expensive equipment, and continuous evaporation losses. Furthermore, solid-state hydrogen storage based on materials (such as porous adsorbents and metal hydrides) often faces challenges such as slow hydrogen adsorption / desorption kinetics, poor cycle reversibility, and high material costs. Although organic liquid hydrogen storage offers high mass hydrogen storage density and good reversibility, it typically involves complex dehydrogenation processes, byproduct generation, and increased system costs.

[0004] Therefore, developing an alternative method that can safely, economically, and efficiently store hydrogen under mild conditions and release hydrogen on demand has become a key breakthrough direction for promoting the large-scale application of hydrogen energy. Summary of the Invention

[0005] The purpose of this invention is to overcome or partially solve the shortcomings of existing technologies, and to provide hydrogen storage materials, preparation methods, applications, and methods for storing and releasing hydrogen. The method for storing and releasing hydrogen in this invention utilizes a near-H2 / H2 ratio. + The redox pair of potential acts as a mediator (M) Red / M Ox This technology achieves safe, economical, and efficient storage and release of hydrogen under mild conditions through two coupled steps: zero-energy hydrogen storage and low-energy hydrogen release.

[0006] This invention provides a hydrogen storage material comprising an absorbent and a catalyst; the absorbent is an aqueous solution containing a first metal ion and a second metal ion; the first metal ion is a metal ion with a redox potential of -0.5V to +0.5V (relative to a standard hydrogen electrode); the second metal ion is a metal ion that can be simultaneously reduced with the first metal ion to form a hydrogen storage alloy; and the catalyst is palladium nanoparticles.

[0007] Furthermore, the aforementioned hydrogen storage material is composed of an absorbent and a catalyst; the mass-to-volume ratio of the catalyst to the absorbent is 0.1~10 mg / mL.

[0008] Furthermore, the concentration of the first metal ion in the absorbent is 0.01~1 mol / L, the concentration of the second metal ion is 0.01~1 mol / L, and the molar ratio of the first metal ion to the second metal ion is 1:1~1:10.

[0009] And / or, the palladium nanoparticles are palladium metal particles with a particle size of less than 50 nm.

[0010] Preferably, the palladium nanoparticles are supported on a titanium foil, that is, the catalyst is a titanium foil supported on palladium nanoparticles.

[0011] Preferably, the method for preparing the palladium nanoparticle-loaded titanium foil includes the following steps: sputtering palladium metal particles with a particle size of less than 50 nm onto the titanium foil using a sputtering instrument, with a sputtering current of 80 mA, a sputtering speed of 0.57 nm / s, and a sputtering time of 100 s.

[0012] The aforementioned titanium foil was used solely for the purpose of facilitating the collection and characterization of the deposited copper-zinc alloy.

[0013] Furthermore, the concentration of the first metal ion in the absorbent is 0.05 mol / L; the concentration of the second metal ion is 0.5 mol / L.

[0014] And / or, the mass-to-volume ratio of the catalyst to the absorbent is 5 mg / mL.

[0015] Furthermore, the first metal ion is a copper ion; the second metal ion is a zinc ion.

[0016] Preferably, the compound containing the first metal ion is copper sulfate, and the compound containing the second metal ion is zinc sulfate.

[0017] In this invention, hydrogen gas reacts spontaneously under the action of hydrogen storage material without the need for external energy input. This process can convert gaseous hydrogen into solid copper-zinc for storage.

[0018] The present invention also provides a method for preparing the aforementioned hydrogen storage material, which includes the following steps:

[0019] (1) Dissolve the compounds containing the first metal ion and the second metal ion in water to obtain an absorbent solution;

[0020] (2) Disperse palladium nanoparticles in the absorption liquid and stir until homogeneous to obtain the final product.

[0021] Preferably, the compound containing the first metal ion is copper sulfate, and the compound containing the second metal ion is zinc sulfate.

[0022] The present invention also provides the use of the aforementioned hydrogen storage materials in hydrogen storage.

[0023] The present invention also provides a method for storing and releasing hydrogen, comprising the following steps:

[0024] (S1) Hydrogen storage: In the hydrogen storage system, hydrogen is introduced into the aforementioned hydrogen storage material to carry out a hydrogen storage reaction, and the gaseous hydrogen is converted into a solid alloy for storage.

[0025] (S2) Hydrogen release: The liquid obtained after the reaction in step (S1) is used as the electrolyte and placed in an electrolytic cell. The solid alloy obtained after the reaction in step (S1) is used as the anode reactant and the cathode is the hydrogen evolution catalyst. The two chambers are separated by a selective diaphragm. Electrolysis is carried out by passing electricity, and hydrogen can be obtained at the cathode.

[0026] Further, in step (S1), the temperature of the hydrogen storage reaction is 0~100℃, and the pressure of the hydrogen storage reaction is 1~10 atm; preferably, the temperature of the hydrogen storage reaction is room temperature (25℃), and the pressure of the hydrogen storage reaction is atmospheric pressure (1 atm).

[0027] And / or, in step (S2), a LiCl aqueous solution with a concentration of 0.5~5M is added to the anode; preferably, a LiCl aqueous solution with a concentration of 1M is added to the anode;

[0028] And / or, in step (S2), the hydrogen evolution catalyst is selected from noble metal catalysts and non-noble metal transition metal compound catalysts; preferably, the hydrogen evolution catalyst is selected from platinum sheets;

[0029] And / or, in step (S2), the selective membrane is an ion-selective membrane;

[0030] And / or, in step (S2), during electrolysis, the current density is 0.25 mA / cm². 2 In this case, the voltage applied is less than 1.0 V. Preferably, when the hydrogen is released, the system can start electrolysis at a low cell voltage of less than 0.5 V.

[0031] Furthermore, in step (S2), the selective diaphragm is a sodium superionic conductor material.

[0032] Preferably, in step (S2), the electrolytic cell is an H-type electrolytic cell.

[0033] Preferably, the selective diaphragm is prepared from the following raw materials in the following weight ratio: 1-5 parts Li2CO3, 0.1-1 parts Al2O3, 5-10 parts TiO2, 0.1-1 parts SiO2, and 15-20 parts NH4H2PO4.

[0034] Preferably, the selective diaphragm is prepared from the following raw materials in the following weight ratio: 3 parts Li2CO3, 0.7~0.8 parts Al2O3, 6~7 parts TiO2, 0.6 parts SiO2, and 15~16 parts NH4H2PO4.

[0035] Preferably, the selective diaphragm is prepared from the following raw materials in the following weight ratio: 3 parts Li2CO3, 0.75 parts Al2O3, 6.69 parts TiO2, 0.6 parts SiO2, and 15.84 parts NH4H2PO4.

[0036] Preferably, the method for preparing the selective diaphragm includes the following steps:

[0037] (a) Mix the raw materials thoroughly;

[0038] (b) The uniformly mixed raw materials are wet ball-milled, with anhydrous ethanol added during ball milling, until the particle size is below 2 micrometers, then dried and calcined;

[0039] (c) The calcined powder is dry ball-milled until the particle size is below 2 micrometers;

[0040] (d) Press into a circular blank, sinter, and a dense selective diaphragm is obtained.

[0041] Preferably,

[0042] In step (b), the rotation speed of the wet ball mill is 300~500 rpm, and the wet ball milling time is 5~10 hours;

[0043] And / or, in step (b), the calcination is performed at 700-900°C for 1-10 hours in an air atmosphere;

[0044] And / or, in step (c), the dry ball milling speed is 300~500 rpm, and the wet ball milling time is 30~100 hours;

[0045] And / or, in step (d), the thickness of the circular blank is less than 1 cm;

[0046] And / or, in step (d), the sintering temperature is 900~1000℃ and the sintering time is 5~10 hours.

[0047] Compared with existing technologies, the chemically reversible hydrogen storage method provided by this invention has at least the following beneficial effects:

[0048] 1) High safety and mild conditions: The entire hydrogen storage process is carried out in a common, non-toxic and harmless gaseous / liquid environment, avoiding extreme conditions such as ultra-high pressure (e.g., 70MPa) or ultra-low temperature (e.g., 20K) required for high-pressure hydrogen storage and liquefied hydrogen. This fundamentally reduces the risk of explosion of high-pressure containers and the loss of liquid hydrogen through volatilization, and significantly improves the safety and stability of the hydrogen storage system.

[0049] 2) High energy efficiency and low cost: The hydrogen storage step is a spontaneous reaction that does not consume electricity; the energy and power required for the hydrogen release step are far lower than those required for direct water electrolysis under the same conditions, resulting in a significant reduction in energy consumption. At the same time, the system has low requirements for the pressure resistance and insulation of key equipment (such as containers and pipelines), which helps to reduce equipment investment and operation and maintenance costs.

[0050] 3) Good reversibility and high cycle life: The mediator is in the oxidized state (M Ox ) and reduced state (M Red The system can reversibly cycle between these components without undergoing irreversible chemical decomposition or structural damage. Theoretically, it can achieve multiple cycles, and the system has good long-term operational stability.

[0051] 4) Easy to transport: Thanks to the stable properties of liquid and solid media, this technology can reuse existing storage and transportation infrastructure in the petrochemical field, thereby significantly reducing system costs and helping hydrogen energy to achieve large-scale, long-distance and distributed utilization.

[0052] 5) On-demand and controllable release: The release rate and total amount of hydrogen can be precisely and flexibly controlled by adjusting the electrolysis voltage and current, which can well match the dynamic needs of downstream hydrogen-using equipment (such as fuel cells).

[0053] In summary, this invention first provides a hydrogen storage material that can efficiently store hydrogen in a safe environment without requiring additional energy, exhibiting high energy efficiency and low cost, and is also recyclable. Furthermore, based on this hydrogen storage material, this invention provides a method for storing and releasing hydrogen. This method reversibly stores and releases hydrogen, solving the problems existing in current hydrogen storage and release technologies, and has promising application prospects.

[0054] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions or alterations can be made without departing from the basic technical concept of the present invention.

[0055] The following detailed embodiments further illustrate the above-described content of the present invention. However, this should not be construed as limiting the scope of the present invention to the following examples. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention. Attached Figure Description

[0056] Figure 1 For different M Ox The images show the metal deposition results during hydrogen storage in the material. a is the SEM image of the blank group; b is the SEM image of the S1-Ni system; c is the SEM image of the S1-Cu system; and d is the TEM image and solution photographs before and after the reaction of the S1-Pt system.

[0057] Figure 2 For different M Ox The optimization results of the materials are shown in the following figures: a) Optical image of the S3-Cu system; b) Optical image of the S3-Zn system; c) Optical image of the S3-CuZn system; d) Optical image of the three M... Ox The ICP characterization results after the material reaction are shown in the figure.

[0058] Figure 3 Figures showing the effects of different catalysts on hydrogen storage reactions: a) UV spectra of the absorbent before and after the reaction without a catalyst; b) SEM image of copper deposition when Pt is used as a catalyst; c) SEM image of copper deposition when carbon nanotubes are used as a catalyst.

[0059] Figure 4 The image shows the surface morphology of a membrane sample used in the hydrogen release system, as observed by scanning electron microscopy (SEM).

[0060] Figure 5 This is a schematic diagram of hydrogen storage and hydrogen release according to the present invention.

[0061] Figure 6 This diagram illustrates the voltage required to release hydrogen under different current conditions in the hydrogen release system of Example 5.

[0062] Figure 7 The following figures show the performance of the commercial ion exchange membrane in Comparative Example 1 in blocking copper ion migration: a) Results for commercially available Nafion; b) Results for Fumasep-FAA-3-50. Detailed Implementation

[0063] The raw materials and equipment used in the specific embodiments of the present invention are all known products, obtained by purchasing commercially available products.

[0064] Example 1: Preparation of the hydrogen storage material of the present invention

[0065] Copper sulfate and zinc sulfate were dissolved in water to obtain an aqueous solution with a copper sulfate (CuSO4) concentration of 0.05 mol / L and a zinc sulfate (ZnSO4) concentration of 0.5 mol / L. Then, titanium foil (Pd / Ti) loaded with palladium nanoparticles was added to the aqueous solution to make the palladium nanoparticle concentration 5 mg / mL, thus obtaining a hydrogen storage material.

[0066] The preparation method of the palladium nanoparticle-loaded titanium foil (Pd / Ti) is as follows: palladium metal particles with a diameter of less than 50 nm are sputtered onto the titanium foil using a sputtering instrument. The sputtering current is 80 mA, the sputtering velocity is 0.57 nm / s, and the sputtering time is 100 s. The titanium foil is only used for convenient collection and characterization of the deposited copper-zinc alloy. In actual hydrogen storage applications, palladium nanoparticles (concentration of 5 mg / mL) can be directly added without being loaded onto the titanium foil.

[0067] Example 2: Redox mediator (M) in hydrogen storage materials Ox ) Filtering

[0068] 1. Material Preparation: Copper sulfate (CuSO4), nickel sulfate (NiSO4), and potassium chloroplatinate (K2PtCl4) were used as M... Ox 50 mL of a 0.05 mol / L aqueous solution was prepared for each experiment, with pure water used as a blank control solution. Palladium nanoparticles (at a concentration of 5 mg / mL) were added as a catalyst to each solution to obtain different hydrogen storage materials, labeled Si-Cu, Si-Ni, Si-Pt, and the blank group, respectively. Palladium nanoparticles refer to palladium metal particles with a diameter of less than 50 nm. Similar to Example 1, the palladium nanoparticles were loaded onto a titanium foil (Pd / Ti). This process involved sputtering the palladium nanoparticles onto the titanium foil using a sputtering instrument at a sputtering current of 80 mA, a sputtering velocity of 0.57 nm / s, and a sputtering time of 100 s. The titanium foil was only used for convenient collection and characterization of the deposited copper-zinc alloy; in practical applications, palladium nanoparticles (at a concentration of 5 mg / mL) can be added directly without being loaded onto the titanium foil.

[0069] 2. Performance test: Transfer 50 mL of the above hydrogen storage material into flasks and react with hydrogen gas at room temperature (25℃) and atmospheric pressure (1 atm) for 30 minutes.

[0070] 3. Results Analysis: Pd / Ti in each group of solutions was characterized by electron microscopy, such as... Figure 1As shown, compared to the blank group, no nickel deposition was observed in the Si-Ni system, therefore it could not store hydrogen (hydrogen storage capacity was 0); copper deposition was observed in the Si-Cu system under mild conditions, exhibiting better hydrogen storage capacity. Although platinum deposition could be achieved in the Si-Pt system, platinum, as a precious metal, is more expensive and heavier than the copper system, thus significantly limiting its economic viability and practicality. Therefore, considering both performance and cost, a copper-based medium is the preferred solution of this invention.

[0071] Example 3: Redox mediator (M) in hydrogen storage materials Ox Optimization

[0072] 1. Material Preparation: Copper sulfate (0.05 mol / L CuSO4), zinc sulfate (0.5 mol / L ZnSO4), and a mixture of copper sulfate and zinc sulfate (0.05 mol / L CuSO4 + 0.5 mol / L ZnSO4) were used as M... Ox Prepare 50 mL of aqueous solution. Add palladium nanoparticles (concentration of palladium nanoparticles: 5 mg / mL) as a catalyst to each solution to obtain different hydrogen storage materials, labeled S3-Cu, S3-Zn, and S3-CuZn respectively. Palladium nanoparticles refer to palladium metal particles with a particle size of less than 50 nm. For example, in Example 1, palladium nanoparticles were loaded onto a titanium foil (Pd / Ti). This process involved sputtering palladium nanoparticles onto the titanium foil using a sputtering instrument with a sputtering current of 80 mA, a sputtering velocity of 0.57 nm / s, and a sputtering time of 100 s.

[0073] 2. Performance test: Transfer 50 mL of the above hydrogen storage material into flasks and react with hydrogen gas at room temperature (25℃) and atmospheric pressure (1 atm) for 30 minutes.

[0074] 3. Results Analysis: Pd / Ti in each group of solutions was characterized by microscopic imaging, such as... Figure 2 As shown in a-2c, metal deposition was observed in both the S3-Cu and S3-CuZn systems under mild conditions; however, no zinc deposition was observed in the S3-Zn system, therefore it could not store hydrogen (hydrogen storage capacity was 0). Further characterization using inductively coupled plasma (ICP) technology yielded the following results: Figure 2 As shown in Figure d, the metal deposition in the S3-CuZn system was superior to that in the S3-Cu system, with a significant increase in Cu content and the appearance of zinc deposition. Therefore, the copper-zinc based medium exhibits better hydrogen storage performance than copper and zinc alone, demonstrating a synergistic effect in hydrogen storage.

[0075] Example 4: Screening of different catalyst materials

[0076] 1. Material preparation: Immobilization of redox mediators (M Ox The solution was an aqueous solution of 0.05 mol / L CuSO4 + 0.5 mol / L ZnSO4. The following catalyst conditions were set for comparison: (A) Blank control (no catalyst); (B) Palladium catalyst, same as in Example 1, with a palladium nanoparticle concentration of 5 mg / mL; (C) Platinum catalyst, obtained by sputtering after replacing palladium in Example 1, with a platinum nanoparticle concentration of 5 mg / mL; (D) Carbon nanotubes (CNTs), with a CNT concentration of 5 mg / mL after adding to the solution. The CuSO4 and ZnSO4 aqueous solutions were mixed with the catalyst (5 mg / mL) and stirred until homogeneous to obtain different hydrogen storage materials.

[0077] 2. Test method: Each system was placed in a hydrogen storage reactor and hydrogen was continuously introduced for 30 minutes at room temperature (25℃) and atmospheric pressure (1 atm) with a hydrogen flow rate of 200 ml per minute. The deposition behavior and reaction rate of copper-zinc alloy during the hydrogen storage process were monitored.

[0078] 3. Results and Discussion: The effects of different catalysts on hydrogen storage reactions are as follows: Figure 3 As shown. By Figure 3 As can be seen from point a, under catalyst-free conditions, UV spectroscopy revealed that the spectra of the absorber before and after the reaction overlapped, proving that the solution composition did not change, and no copper deposition was observed (the amount of copper-zinc deposition was 0). Figure 1 c indicates that significant copper-zinc deposition exists on the surface of the palladium catalyst, corresponding to its fastest hydrogen storage rate (copper-zinc deposition mass ratio of 18:1); from Figure 3 As shown in b and 3c, no copper-zinc deposition was found in SEM characterization when using platinum metal and carbon nanotubes respectively (the amount of copper-zinc deposition was 0).

[0079] The above results indicate that the catalyst is hydrogen and Cu. 2+ and Zu 2+ The key factor for spontaneous reduction reactions under mild conditions is the presence of a catalyst. The noble metal Pd exhibited excellent catalytic activity in this system, while platinum and carbon nanotubes did not show effective catalytic activity under the experimental conditions, indicating that the choice of catalyst has a significant impact on the feasibility of this hydrogen storage system.

[0080] Example 5: Preparation of High-Performance Separator

[0081] This embodiment provides a method for preparing a LATSP solid lithium-ion ceramic separator that can effectively block the migration of copper ions. The specific steps are as follows:

[0082] 1. Raw material ratio and mixing: Weigh 3 g Li2CO3, 0.75 g Al2O3, 6.69 g TiO2, 0.6 g SiO2 and 15.84 g NH4H2PO4 as raw materials and mix them thoroughly.

[0083] 2. Wet milling and pre-calcination: The mixture was placed in a ball mill jar, anhydrous ethanol was added, and wet milling was performed using a planetary ball mill for 5 hours (300 rpm), resulting in a particle size of less than 2 micrometers. After drying, the resulting slurry was calcined at 700°C for 2 hours in air to complete the pre-crystallization.

[0084] 3. Molding and Sintering: The pre-fired powder was dry-milled in a planetary ball mill for 40 hours (400 rpm) to achieve a particle size of less than 2 micrometers. The mixture was then pressed into round blanks with a diameter of 25 mm and a thickness of less than 1 cm. The blanks were then placed in a high-temperature furnace and sintered at 960°C for 6 hours to obtain a dense LATSP ceramic diaphragm.

[0085] 4. Structural and performance characterization: The microstructure of the obtained diaphragm is as follows: Figure 4 As shown, the membrane exhibits high density with no obvious pores or cracks. When assembled in an H-type electrolytic cell for copper ion barrier testing, no copper ions were detected in the cathode-side electrolyte after electrolysis using inductively coupled plasma (ICP) technology. This indicates that the membrane effectively blocks the transmembrane migration of copper ions, ensuring the stability of the hydrogen evolution reaction and the reversibility of the system's cycles.

[0086] Example 6: Performance Verification of the Hydrogen Storage-Release System of Absorbent Materials

[0087] This embodiment demonstrates a complete hydrogen storage-release process constructed using preferred components. A schematic diagram of hydrogen storage and release according to this invention is shown below. Figure 5 As shown.

[0088] Material Preparation: The hydrogen storage material was the same as that in Example 1. Copper sulfate and zinc sulfate were dissolved in water to obtain an aqueous solution with a copper sulfate (CuSO4) concentration of 0.05 mol / L and a zinc sulfate (ZnSO4) concentration of 0.5 mol / L. A titanium foil (Pd / Ti) loaded with palladium nanoparticles was added to the aqueous solution to achieve a palladium nanoparticle concentration of 5 mg / mL, thus obtaining the hydrogen storage material. The preparation method of the palladium nanoparticle-loaded titanium foil (Pd / Ti) was the same as in Example 1.

[0089] Hydrogen storage process (step S1): The above system was placed in a hydrogen storage reactor, and hydrogen gas was introduced at 200 mL / min under normal temperature (25°C) and normal pressure (1 atm) to carry out the hydrogen storage reaction. After 1 hour, a large amount of copper-zinc layer with metallic luster was observed deposited on the Pd surface, and the blue color of the solution lightened, indicating that Cu... 2+ Zn2+ The hydrogen is reduced to CuZn, and the hydrogen gas is converted into a copper-zinc alloy. The solution obtained in this step is used as the electrolyte in the hydrogen release process, and the solid (M) Red It serves as the anolyte in the hydrogen release process.

[0090] Hydrogen release process (step S2): The liquid after the hydrogen storage reaction is used as the electrolyte. A 1M LiCl aqueous solution is added to the anode, and the system is placed in an H-type electrolytic cell. The solid after the hydrogen storage reaction is used as the anode reactant. The cathode is a platinum sheet, and a LATSP lithium-ion solid electrolyte membrane is used as the diaphragm. During electrolysis, continuous and stable hydrogen evolution can be observed at the cathode. The system can start electrolysis at a low cell voltage below 0.5V, and the amount of hydrogen released is positively correlated with the input charge, proving that hydrogen release can be generated on demand. After electrolysis, the anolyte returns to blue, indicating that the copper-zinc alloy has been re-oxidized to Cu. 2+ and Zn 2+ . Figure 6 The diagram shows the voltage required to release hydrogen under different current conditions in the hydrogen release system, illustrating that the hydrogen release process can achieve the goal of releasing hydrogen on demand through voltage control.

[0091] Conclusion: The hydrogen storage material and method provided by this invention can achieve safe, efficient, and reversible hydrogen storage and release under mild conditions. The hydrogen release rate can be controlled by adjusting the electrical energy input, demonstrating the process characteristics of on-demand hydrogen release. The primary evaluation criterion for hydrogen storage and release is safety. This method operates under mild conditions, without involving high temperature and high pressure, thus its safety surpasses that of physical hydrogen storage methods in the field. Secondly, the energy consumption is below 8 kWh / kg H2 (calculated based on the electrical energy consumed in the reaction), far lower than existing hydrogen storage technologies (magnesium-hydrogen storage is above 11 kWh / kg H2). Finally, the hydrogen storage capacity is also a factor. The hydrogen energy in this method exists in the form of copper and zinc, with a theoretical volumetric capacity of 0.22 kg H2 / L to 0.28 kg H2 / L system, far exceeding the US Department of Energy (DOE) 2025 target of 0.04 kg H2 / L system.

[0092] Comparative Example 1: Comparison of Ion-Selective Membranes

[0093] Except for replacing the LATSP membrane in the H-type electrolyzer with commercially available Nafion (cation exchange membrane CEM) and Fumasep-FAA-3-50 (anion exchange membrane AEM), the other conditions were the same as the hydrogen release steps in Example 6. Electrolysis was performed for 24 hours under the same current conditions. During the electrolysis process, blue Cu was observed. 2+ The copper ion gradually diffuses into the anode chamber and contaminates the cathode, indicating varying degrees of copper ion leakage in both the CEM and AEM. Hydrogen evolution performance was characterized using a platinum cathode sheet. Figure 7 The results show that the cathode hydrogen evolution overpotential increases and the hydrogen evolution rate decreases significantly for both CEM and AEM membranes. Ion-selective membranes are crucial for maintaining efficient coupling between the two electrodes and preventing M... Ox Interfering with hydrogen evolution at the cathode is crucial.

[0094] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hydrogen storage material, characterized in that: It consists of an absorbent and a catalyst; the absorbent is an aqueous solution of a first metal ion and a second metal ion; the first metal ion is copper ion; the second metal ion is zinc ion; the catalyst is palladium nanoparticles; the mass-to-volume ratio of the catalyst to the absorbent is 0.1~10 mg / mL; the concentration of the first metal ion in the absorbent is 0.01~1 mol / L, the concentration of the second metal ion is 0.01~1 mol / L; and the molar ratio of the first metal ion to the second metal ion is 1:1~1:

10.

2. The hydrogen storage material according to claim 1, characterized in that: The palladium nanoparticles are palladium metal particles with a particle size of less than 50 nm.

3. The hydrogen storage material according to claim 1, characterized in that: The concentration of the first metal ion in the absorbent is 0.05 mol / L; the concentration of the second metal ion is 0.5 mol / L. And / or, the mass-to-volume ratio of the catalyst to the absorbent is 5 mg / mL.

4. The method for preparing the hydrogen storage material according to any one of claims 1 to 3, characterized in that: It includes the following steps: (1) Dissolve the compounds containing the first metal ion and the second metal ion in water to obtain an absorbent solution; (2) Disperse palladium nanoparticles in the absorption liquid and stir until homogeneous to obtain the final product.

5. Use of the hydrogen storage material according to any one of claims 1 to 3 in storing hydrogen.

6. A method for storing and releasing hydrogen, characterized in that: It includes the following steps: (S1) Hydrogen storage: In the hydrogen storage system, hydrogen is introduced into the hydrogen storage material according to any one of claims 1 to 3 to carry out a hydrogen storage reaction, and the gaseous hydrogen is converted into a solid alloy for storage. (S2) Hydrogen release: The liquid obtained after the reaction in step (S1) is used as the electrolyte and placed in an electrolytic cell. The solid alloy obtained after the reaction in step (S1) is used as the anode reactant and the cathode is the hydrogen evolution catalyst. The two chambers are separated by a selective diaphragm. Electrolysis is carried out by passing electricity, and hydrogen can be obtained at the cathode. The selective diaphragm is prepared from the following raw materials in the following weight ratio: Li2CO3 1~5 parts, Al2O3 0.1~1 parts, TiO2 5~10 parts, SiO2 0.1~1 parts, NH4H2PO4 15~20 parts.

7. The method according to claim 6, characterized in that: In step (S1), the temperature of the hydrogen storage reaction is 0~100℃, and the pressure of the hydrogen storage reaction is 1~10 atm; And / or, in step (S2), a LiCl aqueous solution with a concentration of 0.5~5M is added to the anode; And / or, in step (S2), the hydrogen evolution catalyst is selected from noble metal catalysts and non-noble metal transition metal compound catalysts; And / or, in step (S2), during electrolysis, the current density is 0.25 mA / cm². 2 In this case, the voltage applied is less than 1.0V.

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