Preparation method of hydrogen storage material with CNTs (at) C structure

Abstract

The invention belongs to the field of hydrogen storage materials, and discloses a preparation method of a hydrogen storage material with a CNTs (at) C structure, which comprises the following steps: smoldering and carbonizing walnut shell powder, boiling with hydrochloric acid, washing and the like to prepare a porous carbon core; heating the resin while stirring to a certain fluidity, sequentially adding the prepared porous carbon core, the additive and the curing agent, and stirring to a suspended state; and after drying and curing, calcining under a reducing atmosphere condition to prepare the hydrogen storage material with the CNTs (at) C structure. According to the invention, the used raw materials are few, the process is relatively simple, the preparation cost is low, the preparation process is relatively simple, and the prepared hydrogen storage material with the CNTs (at) C structure is excellent in performance.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen storage materials, and in particular relates to a method for preparing a hydrogen storage material with a CNTs@C structure. Background Art

[0002] With the continuous growth of energy demand in recent years, the reserves of fossil energy have been gradually consumed, which has not only led to a series of environmental problems, but also highlighted the necessity of finding safe, reliable, green and clean energy. Hydrogen energy has abundant reserves, no environmental impact, and advantages in production, lightness and energy density. It has been considered the best choice among many potential energy sources. By using hydrogen energy, it can effectively reduce dependence on oil resources, gradually replace fossil fuels, and realize flexible conversion between heat energy and electrical energy.

[0003] In recent years, with the continuous advancement of research on hydrogen storage materials, these materials have begun to play an important role in various fields, including hydrogen storage, automotive hydrogen energy systems, fuel cell technology, and marine hydrogen energy solutions. However, hydrogen has the characteristics of low density, flammability and explosion at room temperature and pressure, so hydrogen storage and transportation are difficult. In addition, when metal materials are used in hydrogen-containing media for a long time, the mechanical properties of the materials are severely degraded due to hydrogen absorption or hydrogen permeation, and "hydrogen embrittlement" is prone to occur. Therefore, attention should also be paid to hydrogen storage materials and hydrogen transportation environment to ensure the safety of hydrogen during transportation.

[0004] Commonly used hydrogen storage methods are divided into three types: high-pressure gaseous hydrogen storage, solid hydrogen storage and liquid hydrogen storage. Among them, solid hydrogen storage is the safest and most promising hydrogen storage method. Solid hydrogen storage stores hydrogen in solid materials through adsorption or compound forms. It has high safety and can be carried out at a temperature and pressure close to the environment. It has low requirements for energy consumption and equipment and is easy to transport.

[0005] Among them, the document "Preparation Method of Magnesium-based Hydrogen Storage Materials Doped with Oxides" (202410196421.X) discloses a method for preparing an oxide-doped MgH2 hydrogen storage material, wherein different nitrates and anhydrous citric acid are dissolved in deionized water respectively, and four clear and transparent solutions are obtained by stirring the reaction with a magnetic stirrer at room temperature; the reaction temperature is increased, and stirring is continued to obtain four clear and transparent gels; the product is placed in a drying oven, and dried to obtain a fluffy solid, which is then ground to obtain a powdered solid; the product is heated in a tubular furnace and then calcined to obtain an oxide powder; the four oxide powders are respectively put into a ball mill with MgH2 and ball-milled to obtain four oxide-doped magnesium-based hydrogen storage materials. This method requires acid dissolution, stirring to prepare gel, drying, grinding, calcining, and mixing and grinding, and the operation process is complicated.

[0006] The document "A composite hydrogen storage material doped with CNT@TiO2 and NaAlH4 and a preparation method thereof" (202311604609.5) discloses a composite hydrogen storage material doped with CNT@TiO2 and a preparation method thereof. The present invention first prepares CNT@TiO2 by a solvothermal method; then CNT@TiO2 and NaAlH4 are ball-milled and mixed to prepare a composite hydrogen storage material. The method requires ultrasonic dispersion of carbon nanotubes in a prepared dilute nitric acid solution in an anhydrous and oxygen-free atmosphere, and then obtains surface-modified CNTs by centrifugal separation, washing and drying. The modified CNTs are then dissolved in isopropanol, and diethylenetriamine and isopropyl titanate are dripped in sequence, and reacted in a reactor. After multiple centrifugal washing, precipitation and drying, a precursor powder is prepared. Finally, a three-dimensional nested structure CNT@TiO2 is prepared by calcination under Ar gas protection conditions, and then ball-milled with NaAlH4 to prepare a composite material. The preparation process of this method is complicated. At the same time, expensive chemical reagents such as isopropyl alcohol, diethylenetriamine and isopropyl titanate are used, which results in high costs.

[0007] The document "A method for preparing a wood fiber-based aerogel hydrogen storage material" (202410095674.8) discloses a method for preparing a wood fiber-based aerogel hydrogen storage material, which involves physically ball-milling agricultural and forestry biomass wood fibers to less than 100 mesh, dissolving them with ionic liquids, regenerating the fibers to form gels, immersing them in a solution containing modified carbon nanotubes, adding a cross-linking agent to form a gel network structure, and freeze-drying to prepare wood fiber-based aerogels. This method has a complex preparation process and also uses organic and inorganic acids, which is not environmentally friendly. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a method for preparing a hydrogen storage material with a CNTs@C structure; the method comprises the steps of smoldering and carbonizing walnut shell powder, boiling with hydrochloric acid, washing, etc. to prepare a porous carbon core, heating and stirring the resin to a certain fluidity, sequentially adding the prepared porous carbon core, additives and curing agent, stirring to a suspended state, drying and curing, and calcining under reducing atmosphere conditions to prepare a hydrogen storage material with a CNTs@C structure. The present invention uses less raw materials, has a relatively simple process, and has a low preparation cost.

[0009] In order to achieve the above object, the technical solution of the present invention is: A method for preparing a hydrogen storage material with a CNTs@C structure, wherein the following parts are parts by weight, comprises the following steps: Step 1: Preparation of porous carbon core: The walnut shell powder is carbonized in a smoldering furnace at 400-600°C for 1-3 hours, and then the carbonized walnut shell powder is boiled in hydrochloric acid for 1-3 hours, and then washed, dried, and crushed into porous carbon powder for multiple times; Step 2: stirring, drying and calcining; Take 18-42 parts of resin and stir them in a water bath at 70-90°C until they have a certain fluidity. Then add 18-58 parts of porous carbon powder, 2-10 parts of additives, and 0.5-2.5 parts of curing agent in sequence. Stir for 1-5 hours until a suspended state. After drying at 90-110°C and curing at 150-250°C, calcinate at 800-1200°C under reducing atmosphere to prepare CNTs@C structured hydrogen storage materials.

[0010] The particle size of the walnut shell powder is ≤1 μm.

[0011] The resin is one or more of phenolic resin, epoxy resin and polyamide resin, and the solid content is greater than 40%.

[0012] The additive is one or more of ferric nitrate, iron red, and ferrocene, and the purity is greater than 99.9%.

[0013] The curing agent is one or more of triethanolamine and hexamethyltetraethylamine.

[0014] The invention is applied to the preparation of hydrogen storage materials.

[0015] The present invention uses walnut shell powder instead of other organic matter. This is because the walnut shell powder itself has a porous structure. After carbonization, a porous carbon structure organic body is formed. This porous organic body has excellent gas adsorption capacity. In addition, under the action of additives, the resin is efficiently converted into carbon nanotubes, and carbon nanotubes grow on the surface of the porous carbon structure organic body. Both materials have the ability to adsorb hydrogen. Since the particle size of the walnut shell powder is ≤1μm, it is conducive to conversion into a porous carbon structure.

[0016] The invention uses less raw materials, has a simple process, and has a low preparation cost, and the prepared CNTs@C structured hydrogen storage material has superior performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the SEM photograph of the CNTs@C structured hydrogen storage material prepared in Example 1. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below with reference to specific embodiments. The present invention provides a CNTs@C structured hydrogen storage material and a preparation method thereof, wherein the particle size of the walnut shell powder is ≤1 μm; the resin is one or more of phenolic resin, epoxy resin, and polyamide resin, and the solid content is greater than 40%.

[0019] The additive is one or more of ferric nitrate, iron red, and ferrocene, with a purity of more than 99.9%. The curing agent is one or more of triethanolamine and hexamethyltetraethylamine. The following parts are by weight.

[0020] Embodiment 1:

[0021] Step 1: Preparation of porous carbon core: Walnut shell powder with a particle size of 1 μm was carbonized in a smoldering furnace at 400°C for 1 hour, and then the carbonized walnut shell powder was boiled in hydrochloric acid for 1 hour, and then washed several times, dried, and crushed into porous carbon cores; Step 2: stirring, drying and calcining; Take 18 parts of phenolic resin and stir it in a 70℃ water bath until it has a certain fluidity, then add 58 parts of porous carbon powder, 10 parts of ferric nitrate, and 2.5 parts of triethanolamine in sequence, and stir for 1 hour until it is suspended. After drying at 90℃ and curing at 150℃, the CNTs@C structured hydrogen storage material is prepared by calcining at 800℃ under reducing atmosphere.

[0022] Embodiment 2:

[0023] Step 1: Preparation of porous carbon core: Walnut shell powder with a particle size of 0.2 μm was carbonized in a smoldering furnace at 600° C. for 3 h, and then the carbonized walnut shell powder was boiled in hydrochloric acid for 3 h, and then washed, dried, and crushed into porous carbon powder after multiple washings; Step 2: stirring, drying and calcining; Take 42 parts of epoxy resin and stir it in a 90°C water bath until it has a certain fluidity. Then add 18 parts of porous carbon powder, 2 parts of iron red, and 0.5 parts of triethanolamine in sequence and stir for 5 hours until it becomes a suspended state. After drying at 110°C and curing at 250°C, calcination at 1200°C under reducing atmosphere conditions is performed to prepare CNTs@C structured hydrogen storage material.

[0024] Embodiment 3:

[0025] Step 1: Preparation of porous carbon core: Walnut shell powder with a particle size of 0.8 μm was carbonized in a smoldering furnace at 500° C. for 2 h, and then the carbonized walnut shell powder was boiled in hydrochloric acid for 2 h, and then washed, dried, and crushed into porous carbon powder after multiple washings; Step 2: stirring, drying and calcining; Take 40 parts of polyamide resin and stir it in a water bath at 80°C until it has a certain fluidity. Then add 50 parts of porous carbon powder, 8 parts of iron red, and 2 parts of hexamethyltetraethylamine in sequence and stir for 3 hours until it becomes a suspended state. After drying at 100°C and curing at 200°C, calcinate at 1000°C under reducing atmosphere to prepare CNTs@C structured hydrogen storage material.

[0026] Embodiment 4:

[0027] Step 1: Preparation of porous carbon core: Walnut shell powder with a particle size of 0.5 μm was carbonized in a smoldering furnace at 550° C. for 2.5 hours, and then the carbonized walnut shell powder was boiled in hydrochloric acid for 1.5 hours, and then washed, dried, and crushed into porous carbon powder after multiple washings; Step 2: stirring, drying and calcining; Take a mixture of 32 parts of phenolic resin and epoxy resin, stir it in a 90°C water bath until it has a certain fluidity, then add 58 parts of porous carbon powder, 9 parts of ferrocene, and 1 part of hexamethyltetraethylamine in sequence, stir for 4 hours until it becomes a suspended state, and then dry it at 100°C and cure it at 210°C, and calcine it at 1150°C under reducing atmosphere to prepare a CNTs@C structured hydrogen storage material.

[0028] This preparation method has the following advantages: the raw materials are non-toxic, harmless and easy to obtain, so a lower production cost is required; the preparation process only requires carbonization, stirring, drying and sintering processes, so the process is simple.

[0029] The parts of the present invention that are not described in detail are prior art. The above embodiments will help relevant persons in the art to further understand the present invention, but do not limit the present invention in any form. Within the scope of the present invention defined by the attached claims, various changes in form, details or equivalents made using the present invention are all within the protection scope of the present invention.

Claims

1. A method for preparing a hydrogen storage material with a CNTs@C structure, characterized in that: The following parts are by weight, and the method comprises the following steps: Step 1, preparation of porous carbon core: taking walnut shell powder with a particle size of ≤1 μm and carbonizing it in a smoldering furnace at 400-600°C for 1-3 hours, then boiling the carbonized walnut shell powder in hydrochloric acid for 1-3 hours, and then washing it for multiple times, drying it, and crushing it into porous carbon powder; Step 2, stirring, drying and calcining it; taking 18-42 parts of resin and stirring it in a water bath at 70-90°C until it has a certain fluidity, and then adding 18-5 8 parts of porous carbon powder, 2-10 parts of additives, 0.5-2.5 parts of curing agent, stirred for 1-5 hours to a suspended state, then dried at 90-110°C and cured at 150-250°C, and calcined at 800-1200°C under reducing atmosphere to prepare CNTs@C structured hydrogen storage materials; after carbonization, walnut shell powder forms a porous carbon structure organism, and under the action of the additive, the resin is efficiently converted into carbon nanotubes, and carbon nanotubes grow on the surface of the porous carbon structure organism.

2. The method for preparing a CNTs@C structured hydrogen storage material according to claim 1, characterized in that: The resin is one or more of phenolic resin, epoxy resin and polyamide resin, and the solid content is greater than 40%.

3. The method for preparing a CNTs@C structured hydrogen storage material according to claim 1, characterized in that: The additive is one or more of ferric nitrate, iron red, and ferrocene, with a purity of more than 99.9%.

4. The method for preparing a CNTs@C structured hydrogen storage material according to claim 1, characterized in that: The curing agent is one or more of triethanolamine and hexamethyltetraethylamine.

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