Multi-stage pore oriented carbon supported titanium-based composite hydrogen storage material and preparation and application thereof

Abstract

The application discloses a kind of multi-level hole orientation carbon load titanium-based composite hydrogen storage materials and its preparation and application, including the following steps: with (CH3COO)2Zn·2H20, tetrabutyl titanate, organic acid as raw material, ultrasonic treatment is carried out, and ZnTi-MOF-74 NPs is obtained;The ZnTi-MOF-74 NPs are solvent exchanged and treated, and ZnTi-MOF is obtained;In inert atmosphere, the ZnTi-MOF is calcined, and the multi-level hole orientation carbon load titanium-based composite hydrogen storage material H-Ti / C is obtained;By with zinc acetate, titanium salt and organic acid as raw material, through ultrasonic synthesis, solvent exchange and controllable pyrolysis process, multi-level hole orientation carbon load titanium-based composite hydrogen storage material (H-Ti / C) is successfully prepared, finally make material give consideration to high hydrogen storage capacity and fast hydrogen absorption and desorption rate.

Description

Technical Field

[0001] This invention relates to the field of hydrogen storage technology, and in particular to a multi-level porous oriented carbon-supported titanium-based composite hydrogen storage material and its preparation and application. Background Technology

[0002] Solid-state hydrogen storage is a technology that stores hydrogen in solid materials through physical or chemical means. Solid-state hydrogen storage has advantages such as high volumetric hydrogen storage density, good safety, and ease of use, and is considered one of the most commercially promising hydrogen storage methods in the future. Solid-state hydrogen storage is mainly achieved through two mechanisms: physical adsorption and chemical adsorption. Physical adsorption utilizes the high specific surface area of ​​porous materials to adsorb hydrogen molecules onto the material surface. Chemical adsorption involves hydrogen atoms forming ionic or covalent bonds with other elements to generate materials such as metal hydrides. These materials can reversibly absorb and release hydrogen under certain conditions.

[0003] However, the traditional hydrogen storage materials currently used in solid-state hydrogen storage often only perform well in a single mechanism of physical adsorption or chemical adsorption, making it difficult to achieve both high hydrogen storage capacity and excellent hydrogen adsorption and desorption kinetics at the same time.

[0004] Therefore, there is a need to provide a solution that can simultaneously improve the absolute capacity and hydrogen absorption / desorption rate of hydrogen storage materials. Summary of the Invention

[0005] In view of this, this application provides a multi-level porous oriented carbon-supported titanium-based composite hydrogen storage material and its preparation and application, in order to solve the problem of how to simultaneously improve the absolute capacity and hydrogen absorption / desorption rate of hydrogen storage materials.

[0006] To achieve the above technical objectives, this application adopts the following technical solution: In a first aspect, this application provides a method for preparing a hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material, comprising the following steps: Using (CH3COO)2Zn·2H2O, tetrabutyl titanate, and organic acids as raw materials, ZnTi-MOF-74 NPs were obtained by ultrasonic treatment. The ZnTi-MOF-74 NPs were subjected to solvent exchange treatment to obtain ZnTi-MOF; The ZnTi-MOF is calcined under an inert atmosphere to obtain the hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material H-Ti / C.

[0007] Preferably, the organic acid is 2,5-dihydroxyterephthalic acid.

[0008] Preferably, the molar ratio of (CH3COO)2Zn·2H2O to tetrabutyl titanate is 10:1-2.

[0009] Preferably, the molar ratio of (CH3COO)2Zn·2H2O to 2,5-dihydroxyterephthalic acid is 8:1-2.

[0010] Preferably, the solvent used in the solvent exchange process is a hydrochloric acid-ethanol solution.

[0011] Preferably, in the hydrochloric acid-ethanol solution, the volume ratio of hydrochloric acid to water is 1:12, and the volume ratio of hydrochloric acid to ethanol is 1:2-47.

[0012] Preferably, the final calcination temperature is 1000-1200℃, and the calcination time is 4-5 hours.

[0013] Preferably, the temperature is increased to the final calcination temperature at a heating rate of 5-8℃ / min.

[0014] Secondly, this application provides a multi-level porous oriented carbon-supported titanium-based composite hydrogen storage material.

[0015] Thirdly, this application provides an application of a multi-level porous oriented carbon-supported titanium-based composite hydrogen storage material in solid-state hydrogen storage.

[0016] The beneficial effects of this application are as follows: This application successfully prepared a hierarchical porous carbon-supported titanium-based composite hydrogen storage material (H-Ti / C) using zinc acetate, titanium salt, and organic acids as raw materials through ultrasonic synthesis, solvent exchange, and controlled pyrolysis. Leveraging the atomic-level dispersion and ordered pore structure of titanium in the MOF precursor, uniform nano-titanium particles were formed in situ on the porous carbon framework after pyrolysis. This solved the problem of titanium particle agglomeration and deactivation through the anchoring effect of tetrabutyl titanate-OC chemical bonds and the nano-confinement effect of the pores. Furthermore, the multi-level channels inherited from the MOF template—micropore-mesopore-macropore—achieved rapid hydrogen transport and efficient enrichment. Simultaneously, the highly graphitized carbon framework, acting as an excellent thermally conductive network, promptly dissipated the heat of reaction. This resulted in a synergistic effect of enrichment, transport, and fixation between the physical adsorption of porous carbon and the chemical hydrogen storage of nano-titanium, significantly reducing the hydrogen absorption energy barrier and improving kinetic performance. Ultimately, the material achieved both high hydrogen storage capacity and rapid hydrogen absorption / desorption rates. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0018] Figure 1 The image shows a scanning electron microscope (SEM) image of the material obtained in Example 1. Figure 2This is a comparison diagram of hydrogen adsorption between the materials obtained in Example 1 and Comparative Example 3; Figure 3 The absolute hydrogen absorption capacity and hydrogen absorption / desorption rate of the materials prepared in different embodiments and comparative examples are shown. Detailed Implementation

[0019] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0020] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0023] Unless otherwise explicitly defined and specified herein, all technical and scientific terms used in this application shall have the generally accepted meanings understood by one of ordinary skill in the field of chemical and chemical materials technology (including but not limited to polymer chemistry, inorganic chemistry, organic synthesis, catalysis chemistry, materials processing, and chemical unit operations) based on their professional knowledge and conventional practice. The use of any terminology herein is intended to describe the specific embodiments of this application in the clearest and most accurate manner, so as to fully disclose the technical solution. Such use shall not in any way be construed as a limitation on the scope of the claims, nor does it imply the exclusion of equivalent technical solutions that could be reasonably known by one of skill in the art based on the concept of this application.

[0024] The terms "comprising," "including," "having," "containing," and any grammatical variations thereof, or similar expressions used in the specification, claims, and drawings of this application, are all open-ended and non-exhaustive descriptive terms. Their purpose is to explicitly describe the existence of the stated technical features, components, steps, or parts, while explicitly allowing and covering the possibility that other features, components, steps, parts, or any combinations thereof not explicitly listed may exist or be added to the technical solution, as long as such additions do not destroy the integrity and inventiveness of the original technical solution.

[0025] When the terms "embodiments," "some embodiments," or "specific embodiments" are mentioned in the specification, they refer to examples that, in conjunction with the specific parameters, materials, steps, and results described in that section, constitute one or a group of examples for implementing the technical solutions of this application. These embodiments are used for full disclosure and illustrative purposes, not for exhaustive enumeration. Those skilled in the art should understand that, without departing from the overall inventive concept of this application, the various technical features disclosed in different embodiments can be combined, substituted, modified, or deleted to form other implementation methods that are not listed one by one in the specification but also fall within the protection scope of this application.

[0026] Unless otherwise expressly specified and limited, all terms related to chemical process operations, material preparation, processing and analytical testing involved in this application shall be interpreted in the broadest sense based on the conventional understanding of those skilled in the art.

[0027] Regarding performance testing and structural characterization, all testing and characterization methods involved in this application, unless otherwise specified, refer to conventional methods known in the art. Specific testing conditions may be selected and adjusted according to the sample properties and relevant national standards, international standards, or industry-standard methods. Test items may include mechanical properties (such as tensile, bending, and impact strength), thermal properties (such as DSC and TGA analysis), and chemical stability (such as solvent resistance and acid / alkali corrosion resistance). Structural characterization methods may include FT-IR, NMR, XRD, SEM, TEM, and BET. All test results should be understood to be within the allowable range of conventional experimental errors.

[0028] Regarding numerical values ​​and ranges, all parameter ranges expressed in this application in the form of "from a certain value to a certain value" should be understood as explicitly disclosing the endpoints of the range, each specific numerical point between the endpoints, and all sub-ranges formed by any two numerical points within the range. For example, "30℃ to 80℃" discloses 30, 31, ..., 80℃, as well as sub-ranges such as 30-50℃, 45-70℃, etc. When a numerical value is preceded by "about," "approximately," or similar words, it indicates that the numerical value is allowed to have reasonable errors recognized in the art under the measurement or control conditions, which can generally be understood as the deviation allowed by relevant standards or a normal fluctuation range of ±5% or ±10%.

[0029] Metal-organic frameworks (MOFs), with their fine crystal structures and diverse compositions, can serve as sacrificial templates for the preparation of porous carbons with various controlled morphologies and compositions through inheritable carbonization strategies, leading to the development of various nanomaterials with novel micro / nanostructures. On one hand, the periodic distribution of metal ions or metal clusters and organic ligands inhibits the aggregation of metal nanoparticles during pyrolysis, resulting in catalysts exhibiting uniformly dispersed active sites. On the other hand, MOFs with different metal ions, organic ligands, morphologies, and structures can be correspondingly transformed into various carbon-based materials with tunable structures and compositions. The derivatives obtained from the pyrolysis of MOF precursors can well inherit their original structural characteristics, and the resulting hierarchical porous structure facilitates the exposure of more active sites. Furthermore, the formed carbon layer enhances the stability of the catalytic centers.

[0030] Based on this, this application was created.

[0031] This application provides a method for preparing a hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material, comprising the following steps: Using (CH3COO)2Zn·2H2O, tetrabutyl titanate, and organic acids as raw materials, ZnTi-MOF-74 NPs were obtained by ultrasonic treatment. The ZnTi-MOF-74 NPs were subjected to solvent exchange treatment to obtain ZnTi-MOF; The ZnTi-MOF was calcined under an inert atmosphere to obtain the hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material H-Ti / C, in which Zn sublimated at 1000℃.

[0032] In this application, bimetallic ZnTi-MOF-74 NPs are used as precursors. A novel polyhedral framework ZnTi-MOF is obtained through acid treatment. Then, ZnTi-MOF is used as a self-sacrificing template for carbonization to obtain a hierarchical porous carbon-supported titanium material with preserved polyhedral morphology. It has a hierarchical porous structure and polyhedral morphology, realizing the synergistic effect of physical adsorption and chemical adsorption. The synthesized H-Ti / C has good adsorption performance. During the adsorption process, the carbon support can significantly stabilize the active sites of Ti and prevent their aggregation. At the same time, the hierarchical porous structure and the polyhedral orientation structure generated after acid treatment help the rapid mass and heat transfer of the reaction matrix, thereby significantly improving the hydrogen charge / decharge rate and cycle efficiency.

[0033] Specifically, the material structure comprises a porous carbon framework serving as the physical adsorption domain, whose enormous specific surface area enables rapid and reversible adsorption of large quantities of hydrogen molecules via van der Waals forces; and uniformly dispersed and anchored nano-titanium particles on the carbon framework, serving as the chemisorption domain, which can chemically react with hydrogen to generate hydrides, providing a high volumetric hydrogen storage density. The synergistic effect of these two components lies in the porous carbon framework acting as an efficient hydrogen enrichment and transport channel, significantly increasing the contact frequency between hydrogen molecules and nano-titanium particles, thereby lowering the energy barrier of the chemisorption reaction and greatly improving the hydrogen adsorption / desorption kinetics while maintaining high storage capacity.

[0034] This application uses a structurally tunable MOF as a template and, through controlled pyrolysis, enables the final carbon material to precisely inherit the ordered pore structure of the precursor, forming a multi-level pore system with micropores, mesopores, and macropores working in tandem. Macropores act as the main channels for gas transport, enabling rapid hydrogen permeation; mesopores act as branch channels, uniformly distributing hydrogen throughout the material; and micropores serve as the final destination, enriching hydrogen molecules and providing a large physical adsorption surface area. Simultaneously, by controlling the pyrolysis process, the carbon framework achieves high graphitization, constructing a highly efficient thermally conductive network. Since the hydrogen absorption and desorption processes are accompanied by strong thermal effects, this thermally conductive network can rapidly conduct or transfer the heat of reaction, avoiding localized overheating or overcooling. Therefore, the hydrogen storage material of this application ensures efficient hydrogen transport and heat management, improving the hydrogen charging / decharging rate and cycle efficiency of the material.

[0035] In addition, this application uses (CH3COO)2Zn·2H2O and tetrabutyl titanate as raw materials to prepare ZnTi-MOF-74 NPs. The micro / mesoporous channels of MOF-derived carbon are used as nanoreactors to synthesize titanium particles in situ and confine them inside the channels during pyrolysis. The steric hindrance effect is used to prevent particle migration and agglomeration, so that the size is stabilized at the nanoscale. At the same time, oxygen-containing functional groups are introduced by using organic acids as raw materials. These functional groups form Ti-OC chemical bonds with titanium particles during pyrolysis, which firmly anchor the particles to the carbon matrix, thereby effectively maintaining the stability of active sites and preventing particle deposition during material loading or use. This avoids the problem of easy agglomeration and deactivation of nano-titanium particles, achieves stable dispersion of titanium, and improves the effect of chemical adsorption.

[0036] In some embodiments, the organic acid is 2,5-dihydroxyterephthalic acid.

[0037] In this embodiment, 2,5-dihydroxyterephthalic acid, as an organic acid, is beneficial for introducing abundant oxygen-containing functional groups (especially phenolic hydroxyl groups) into the MOF framework. These functional groups can form stable Ti-OC chemical bonds with titanium during subsequent pyrolysis, firmly anchoring titanium nanoparticles to the carbon matrix. At the same time, its dihydroxy structure helps to regulate the crystal morphology of MOF, forming a regular polyhedral structure. If other organic acids are selected, the types or number of oxygen functional groups will be insufficient, making it impossible to effectively anchor titanium particles. During pyrolysis, titanium is prone to migration and aggregation, and the regularity of MOF morphology will decrease.

[0038] In some embodiments, the molar ratio of (CH3COO)2Zn·2H2O to tetrabutyl titanate is 10:1.

[0039] In this embodiment, the molar ratio is conducive to the formation of a bimetallic coordination structure. Zinc acts as the main metal node to maintain the stability of the MOF-74 framework, while titanium is uniformly doped into the framework in an appropriate proportion. After pyrolysis, the titanium particles are highly dispersed and uniform in size. At the same time, zinc sublimates at high temperature to create pores, forming abundant mesopores and macropores. If the molar ratio is higher than this, the titanium content is too low, resulting in insufficient chemical adsorption active sites after pyrolysis and a decrease in the hydrogen storage capacity of the material. If the molar ratio is lower than this, the titanium content is too high, and titanium hydrolysis and agglomeration are prone to occur during MOF synthesis, destroying the framework regularity. After pyrolysis, the titanium particle size increases and the distribution becomes uneven, even blocking the pores. Meanwhile, ZnTi-MOF-74 is prepared from (CH3COO)2Zn·2H2O. NPs are beneficial for hierarchical porous structures. If (CH3COO)2Zn·2H2O is replaced with other raw materials, it will be difficult to completely remove them at conventional carbonization temperatures. The residual oxides will block the pores, cover the active sites, and fail to form the macroporous structure induced by Zn sublimation, resulting in a significant reduction in the specific surface area and pore volume of the material.

[0040] In some embodiments, the molar ratio of (CH3COO)2Zn·2H2O to 2,5-dihydroxyterephthalic acid is 8:1.

[0041] In this embodiment, this molar ratio is beneficial for forming a complete MOF-74 crystal structure, ensuring that the metal nodes and organic ligands are fully coordinated, and obtaining a polyhedral precursor with high crystallinity and regular morphology. If the molar ratio is higher than this, there will be an excess of metal ions and insufficient ligands. Uncoordinated metal ions are prone to forming oxide impurities during the synthesis process, and inactive residues will be generated after pyrolysis, affecting the purity and pore structure of the material. If the molar ratio is lower than this, there will be insufficient ligands, and there may be unreacted ligand residues in the MOF framework. After pyrolysis, the proportion of amorphous carbon will increase, reducing the degree of graphitization and conductivity.

[0042] In some embodiments, the solvent used in the solvent exchange process is a hydrochloric acid-ethanol solution.

[0043] In some embodiments, the hydrochloric acid-ethanol solution has a hydrochloric acid to water volume ratio of 1:12 and a hydrochloric acid to ethanol volume ratio of 1:47.

[0044] In some embodiments, the final calcination temperature is 1000-1200℃, and the calcination time is 4-5h.

[0045] In this embodiment, within the target temperature range, it is beneficial for the material to be fully carbonized and for Zn to sublimate; if the temperature is below this range, the material cannot be fully carbonized.

[0046] In some embodiments, the temperature is increased to the final calcination temperature at a heating rate of 5-8°C / min.

[0047] In this embodiment, the heating rate facilitates the gradual decomposition and carbonization of organic ligands during pyrolysis, ensuring slow framework shrinkage and complete inheritance of the polyhedral morphology and pore structure of the MOF. Simultaneously, zinc sublimates uniformly at this rate, forming interconnected multi-level pores. If the heating rate is higher than this, the pyrolysis becomes too violent, and the rapid escape of gas can easily lead to framework collapse, pore structure destruction, poor morphology retention, and agglomeration of titanium particles due to rapid heating. If the heating rate is lower than this, the pyrolysis time becomes too long, energy consumption increases, production efficiency decreases, and the carbon framework may shrink excessively and the specific surface area decreases due to prolonged high temperature.

[0048] This application provides a multi-level porous oriented carbon-supported titanium-based composite hydrogen storage material.

[0049] This application provides an application of a hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material in solid-state hydrogen storage.

[0050] The following specific embodiments further illustrate this solution.

[0051] Example 1 A method for preparing a hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material includes the following steps: 0.55 g (CH3COO)2Zn·2H2O (2.5 mmol) and tetrabutyl titanate were ultrasonically dissolved in 200 mL of methanol solution. After the reagents were dissolved, 50 mL of methanol solution containing 200 mg (0.3 mmol) 2,5-dihydroxyterephthalic acid was poured into the above solution, and the mixture was further ultrasonicated for about 30 min. The resulting precipitate was labeled ZnTi-MOF-74 NPs. It was washed with methanol and then washed three times with water to remove unreacted components. The precipitate was then dried in a vacuum drying oven at 65 °C for later use. The obtained ZnTi-MOF-74 NPs (200 mg) were mixed with a 0.2 mol / L hydrochloric acid-ethanol solution (hydrochloric acid and water volume ratio of 1:12, with ethanol as solvent), stirred for 6 h, and then purified, centrifuged and dried to obtain a white solid with high crystallinity, which was named ZnTi-MOF. The obtained ZnTi-MOF was placed in a tube furnace and heated to 1000℃ at a heating rate of 5℃ / min under an Ar atmosphere, and held for 4 hours. When the temperature cooled to room temperature, the resulting black powder was denoted as H-Ti / C, which represents polyhedral hierarchical porous Ti (abbreviated as H-Ti / C). The scanning electron microscope image of H-Ti / C is shown below. Figure 1 As shown, from the scan Figure 1 As can be seen, the morphology of the carbon material polyhedron can be preserved, and a dense porous structure is observed on the surface, proving the successful preparation of Ti(H-Ti / C) with a polyhedral hierarchical porous structure.

[0052] Comparative Example 1 A method for preparing a composite hydrogen storage material includes the following steps: 0.55 g (CH3COO)2Zn·2H2O (2.5 mmol) was sonicated and dissolved in 200 mL of methanol solution. After the reagent was dissolved, 50 mL of methanol solution containing 200 mg (0.3 mmol) 2,5-dihydroxyterephthalic acid was poured into the above solution, and the mixture was sonicated for about 30 min. The precipitate obtained was named Zn-MOF-74 NPs. It was washed with methanol and then washed three times with water to remove unreacted components. It was then dried in a vacuum drying oven at 65 °C for later use. The obtained Zn-MOF-74 NPs (200 mg) were mixed with a 0.2 mol / L hydrochloric acid-ethanol solution (hydrochloric acid and water volume ratio of 1:12, with ethanol as solvent), stirred for 6 h, and then purified, centrifuged and dried to obtain a white solid with high crystallinity, which was denoted as Zn-MOF. The obtained Zn-MOF was placed in a tube furnace and heated to 1000℃ at a heating rate of 5℃ / min under the protection of Ar atmosphere, and held for 4h. When the temperature was cooled to room temperature, the black powder obtained was denoted as HC, which is the polyhedral hierarchical porous carbon (abbreviated as HC).

[0053] Comparative Example 2 A method for preparing a hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material includes the following steps: 0.55 g (CH3COO)2Zn·2H2O (2.5 mmol) and tetrabutyl titanate were ultrasonically dissolved in 200 mL of methanol solution. After the reagents were dissolved, 50 mL of methanol solution was poured into the above solution, and the mixture was further ultrasonically treated for about 30 min. The precipitate obtained was denoted as Zn-MOF-74 NPs. It was washed with methanol and then washed three times with water to remove unreacted components. It was then dried in a vacuum drying oven at 65 °C for later use. The obtained ZnTi-MOF-74 NPs (200 mg) were mixed with a 0.2 mol / L hydrochloric acid-ethanol solution (hydrochloric acid and water volume ratio of 1:12, with ethanol as solvent), stirred for 6 h, and then purified, centrifuged and dried to obtain a white solid with high crystallinity, which was named ZnTi-MOF. The obtained ZnTi-MOF was placed in a tube furnace and heated to 1000℃ at a heating rate of 5℃ / min under an Ar atmosphere, and held for 4 hours. When the temperature cooled to room temperature, the resulting black powder was denoted as Ti / C. The scanning image is shown below. Figure 2 As shown, it has no polyhedral morphology and no dense pores.

[0054] Testing and Evaluation The absolute hydrogen absorption capacity and hydrogen absorption / desorption rate of the materials prepared in different embodiments and comparative examples were tested, and the results are as follows: Figure 3 As shown in the figure, a comparison between Example 1 and Comparative Example 2 reveals that the H-Ti / C formed after ZnTi-MOF carbonization exhibits a typical Type IV isotherm and a significant hysteresis loop, indicating the formation of a micro-mesoporous structure. The tetrabutyl titanate / C curve obtained by direct carbonization without acid treatment also shows a significant hysteresis loop and exhibits typical mesoporous characteristics, but its hydrogen adsorption capacity is much lower than that of H-Ti / C.

[0055] In summary, this application uses MOFs as precursors and, through acid treatment, derives a novel hierarchical porous carbon-supported titanium nanocomposite hydrogen storage material, achieving a synergistic effect of physical and chemical adsorption while balancing high capacity and rapid kinetics. By employing nanoconfining effects and surface anchoring strategies, it addresses the issues of active sites easily agglomerating during repeated hydrogen charging and discharging, and easily depositing at the bottom during loading. The hierarchical pore structure simultaneously achieves high specific surface area and efficient heat and mass transfer in the hydrogen storage material, improving its charging / discharging rate and cycling rate. Precise morphology control and structural design enhance the material's stability and cycle life.

[0056] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material, characterized in that, Includes the following steps: Using (CH3COO)2Zn·2H2O, tetrabutyl titanate, and organic acids as raw materials, ZnTi-MOF-74NPs were obtained by ultrasonic treatment. The ZnTi-MOF-74 NPs were subjected to solvent exchange treatment to obtain ZnTi-MOF; The ZnTi-MOF is calcined under an inert atmosphere to obtain the hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material H-Ti / C.

2. The preparation method according to claim 1, characterized in that, The organic acid is 2,5-dihydroxyterephthalic acid.

3. The preparation method according to claim 1, characterized in that, The molar ratio of (CH3COO)2Zn·2H2O to tetrabutyl titanate is 10:1-2.

4. The preparation method according to claim 2, characterized in that, The molar ratio of (CH3COO)2Zn·2H2O to 2,5-dihydroxyterephthalic acid is 8:1-2.

5. The preparation method according to claim 1, characterized in that, The solvent used in the solvent exchange process is a hydrochloric acid-ethanol solution.

6. The preparation method according to claim 5, characterized in that, In the hydrochloric acid-ethanol solution, the volume ratio of hydrochloric acid to water is 1:12, and the volume ratio of hydrochloric acid to ethanol is 1:2-47.

7. The preparation method according to claim 1, characterized in that, The final calcination temperature is 1000-1200℃, and the calcination time is 4-5 hours.

8. The preparation method according to claim 7, characterized in that, Heat to the final calcination temperature at a heating rate of 5-8℃ / min.

9. A hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material obtained by the preparation method according to any one of claims 1-8.

10. The application of the hierarchical porous oriented carbon-supported titanium-based composite hydrogen storage material as described in claim 9 in solid-state hydrogen storage.

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