阅读说明：本技术 一种超微碳孔NaAlH4储氢材料及其制备方法 (Ultramicro carbon pore NaAlH4Hydrogen storage material and method for producing the same ) 是由 高志杰 黄晓明 谷艺宸 李文晶 李永涛 王宇灿 李海文 于 2021-09-16 设计创作，主要内容包括：本发明属于新能源氢能的储氢材料与技术领域,具体公开了一种利用超微碳孔基体负载NaAlH-(4)的储氢材料及其制备方法。本发明制备的超微碳孔约束的NaAlH-(4)储氢材料,由超微碳孔约束NaAlH-(4)颗粒,直径能达到2纳米以下,其制备步骤是：首先将NaAlH-(4)粉料和超微碳孔粉料Z混合均匀后,放入密闭容器并抽真空；再将所述真空容器在恒温185℃～195℃保温一段时间；待真空容器冷却后,最后通过机械研磨得到超微碳孔储氢NaAlH-(4)-C粉料。本发明制备的超微碳孔NaAlH-(4)储氢粉料既改善了储氢材料的脱加氢性能,又能不影响其在工业中进行的大规模生产。(The invention belongs to the field of hydrogen storage materials of new energy hydrogen energy and technology, and particularly discloses a method for loading NaAlH by utilizing an ultramicro carbon pore matrix 4 The hydrogen storage material and the preparation method thereof. The prepared NaAlH with the restraint of ultramicro carbon pores 4 Hydrogen storage material of NaAlH confined by ultramicro carbon pores 4 The particle with the diameter of less than 2 nanometers is prepared by the following steps: firstly, NaAlH is added 4 After uniformly mixing the powder material and the ultramicro carbon hole powder material Z, putting the mixture into a closed container and vacuumizing the closed container; then keeping the temperature of the vacuum container at the constant temperature of 185-195 ℃ for a period of time; after the vacuum container is cooled, the ultramicro carbon pore hydrogen storage NaAlH is obtained by mechanical grinding 4 -C powder. The ultramicro carbon pore NaAlH prepared by the invention 4 The hydrogen storage powder material not only improves the dehydrogenation performance of the hydrogen storage material, but also does not influence the large-scale production of the hydrogen storage material in industry.)

1. Ultramicro carbon pore NaAlH₄The preparation method of the hydrogen storage material is characterized by comprising the following steps:

s1, preparing ultramicro carbon pore powder Z;

s2, adding NaAlH₄Uniformly mixing the powder material and the ultramicro carbon hole powder material Z to obtain a mixture, transferring the mixture into a closed container, heating to 185-195 ℃ under a vacuum condition, and then preserving heat to obtain a hydrogen storage mixed material;

s3, cooling and grinding the hydrogen storage mixed material processed in the step S2 to obtain the ultramicro carbon pore hydrogen storage NaAlH₄-C powder.

2. The ultramicro carbon pore NaAlH according to claim 1₄The preparation method of the hydrogen storage material is characterized in that the preparation method of the ultramicro carbon pore powder Z in the step S1 comprises the following steps:

s11, adding the PEO-PPO-PEO triblock copolymer into a hydrochloric acid solution, and standing or uniformly stirring to obtain a mixed solution;

s12, adding diethyl carbonate into the mixed solution prepared in the step S11, stirring uniformly, standing, carrying out suction filtration, collecting filtrate, washing, drying and grinding the filtrate to obtain powder X;

s13, fully dissolving 1, 4-diacetylene benzene powder and powder X in a sulfuric acid solution, evaporating to dryness to obtain powder Y, and heating and carbonizing the powder Y in a protective gas atmosphere to obtain carbonized powder Y;

s14, adding the carbonized powder Y into a hydrochloric acid solution, uniformly stirring, standing, filtering, collecting a filtrate, washing and drying the filtrate to obtain the ultramicro carbon pore powder Z.

3. The ultramicro carbon pore NaAlH according to claim 2₄The preparation method of the hydrogen storage material is characterized in that the mass ratio of the diethyl carbonate to the PEO-PPO-PEO triblock copolymer in the step S12 is 1: 1.8-2.2; in the step S13, the mass ratio of the 1, 4-diacetylene benzene powder to the sulfuric acid solution to the powder X is 1: 3.5-4.5: 0.6-0.8, wherein the mass fraction of the sulfuric acid solution is 10-20 wt%.

4. The ultramicro carbon pore NaAlH according to claim 1₄The method for producing a hydrogen storage material is characterized in that NaAlH is used in the step S2₄The mass ratio of the powder material to the ultramicro carbon hole powder material Z is 1: 1.2-1.4.

5. The ultramicro carbon pore NaAlH according to claim 1₄The preparation method of the hydrogen storage material is characterized in that the heat preservation time in the step S2 is calculated according to the heat preservation time of 0.01 hour per gram of mixture.

6. The ultramicro carbon pore NaAlH according to claim 2₄The preparation method of the hydrogen storage material is characterized in that the mass ratio of the PEO-PPO-PEO triblock copolymer to the hydrochloric acid solution in the step S11 is 1: 45-55, wherein the mass fraction of the hydrochloric acid solution is 10-20 wt%.

7. The ultramicro carbon pore NaAlH according to claim 2₄The preparation method of the hydrogen storage material is characterized in that the grain diameter of the powder X obtained in the step S12 is less than or equal to 100 mu m; in the step S13, the protective gas is argon, the heating carbonization treatment temperature of the powder Y is 1200-1500 ℃, and the carbonization time is calculated according to 0.05 hour of carbonization of each gram of powder Y.

8. The ultramicro carbon pore NaAlH according to claim 2₄The preparation method of the hydrogen storage material is characterized in that the drying temperature in the step S12 is 350-450 ℃; the evaporation temperature in the step S13 is 65-90 ℃; the mass fraction of the hydrochloric acid solution in the step S14 is 10-20 wt%, the drying temperature is 200-300 ℃, and the drying time is calculated by taking the mass of the filtered substances collected in the step S14 as the total mass and drying the filtered substances for 0.1 hour per gram of the total mass.

9. Ultramicro carbon pore NaAlH prepared by using preparation method of any one of claims 1-8₄A hydrogen storage material product.

10. The ultramicro carbon pore NaAlH as set forth in claim 9₄Use of a hydrogen storage material product in a hydrogen storage product.

Technical Field

The invention belongs to the field of hydrogen storage materials of new energy hydrogen energy and technology, and particularly relates to a method for loading NaAlH by utilizing an ultramicro carbon pore matrix₄The hydrogen storage material and the preparation method thereof.

Background

Among many new energy sources, hydrogen energy is one of the future energy sources with great development potential. The hydrogen energy is a clean energy carrier and has the characteristics of storage and transportation. At present, it is an ideal low-pollution or even zero-pollution vehicle energy source, and its development may bring about significant changes in energy structure in the long run. However, in practical applications, how to realize high-density and secure storage becomes a current technical bottleneck. It is known that hydrogen storage methods are classified into high-pressure gaseous hydrogen storage, low-temperature liquid hydrogen storage, and solid material hydrogen storage according to three different states of hydrogen. Solid-state hydrogen storage is achieved by the action of hydrogen with a material to form a compound or solid solution, as opposed to gaseous or liquid hydrogen storage. The solid hydrogen storage material has hydrogen storage density about 1000 times that of gaseous hydrogen storage under the same temperature and pressure condition, proper hydrogen absorbing and releasing speed and high safety. The solid hydrogen storage material is the most widely used hydrogen storage material at present due to strong hydrogen storage capacity, little pollution, high safety factor and mature preparation process. However, the storage density of the solid hydrogen storage alloys developed at present is low (-2 wt%), and it is difficult to meet the actual demand. Therefore, the research on the high-capacity solid hydrogen storage material has important practical value and can promote the large-scale application of the hydrogen fuel cell.

NaAlH₄The hydrogen storage material has higher theoretical hydrogen storage amount, but the decomposition and hydrogenation processes are accompanied with the damage and reconstruction of crystal lattices and chemical bonds, so that the problems of slow dynamic performance and poor reversible hydrogenation reaction exist. Aiming at the problems, the preparation of carbon pore-constrained NaAlH by adopting a wetting impregnation method is researched₄The dehydrogenation performance is greatly improved, and the diameter of carbon pores can reach below 1 nm. However, the wet impregnation method is very difficult to apply to industrial mass production, and the method of melting impregnation to prepare NaAlH has been studied₄Loaded into mesoporous carbon (carbon pore diameter)2-10 nm), not only improves the dehydrogenation performance of the hydrogen storage material, but also carries out large-scale production of the hydrogen storage material in the industry. The smaller the diameter of the carbon pore is, the better the restriction effect of the nano carbon pore is, if a melt impregnation method is adopted, NaAlH can be obtained₄The carbon pore diameter of the hydrogen storage material is ultra-microporous with the diameter less than 2 nm, so that the dehydrogenation performance and the hydrogen storage density of the hydrogen storage material can be further improved in practical industrial application.

Disclosure of Invention

Aiming at the problems and the defects in the prior art, the invention aims to provide the ultramicro carbon pore NaAlH₄Hydrogen storage materials and methods of making the same.

Based on the purpose, the invention adopts the following technical scheme:

the invention provides a first aspect of ultramicro carbon pore NaAlH₄The preparation method of the hydrogen storage material comprises the following steps:

s1, preparing ultramicro carbon pore powder Z;

s2, adding NaAlH₄Uniformly mixing the powder material and the ultramicro carbon hole powder material Z to obtain a mixture, transferring the mixture into a closed container, heating to 185-195 ℃ under a vacuum condition, and then preserving heat to obtain a hydrogen storage mixed material;

s3, cooling and grinding the hydrogen storage mixed material processed in the step S2 to obtain the ultramicro carbon pore hydrogen storage NaAlH₄-C powder.

Preferably, the preparation method of the ultrafine carbon pore powder Z in step S1 is:

s11, adding the PEO-PPO-PEO triblock copolymer into a hydrochloric acid solution, and standing or uniformly stirring to obtain a mixed solution;

s12, adding diethyl carbonate into the mixed solution prepared in the step S11, stirring uniformly, standing, carrying out suction filtration, collecting filtrate, washing, drying and grinding the filtrate to obtain powder X;

s13, fully dissolving 1, 4-diacetylene benzene powder and powder X in a sulfuric acid solution, evaporating to dryness to obtain powder Y, and heating and carbonizing the powder Y in a protective gas atmosphere to obtain carbonized powder Y;

s14, adding the carbonized powder Y into a hydrochloric acid solution, uniformly stirring, standing, filtering, collecting a filtrate, washing and drying the filtrate to obtain the ultramicro carbon pore powder Z.

Preferably, the mass ratio of the diethyl carbonate to the PEO-PPO-PEO triblock copolymer in the step S12 is 1: 1.8-2.2; in the step S13, the mass ratio of the 1, 4-diacetylene benzene powder to the sulfuric acid solution to the powder X is 1: 3.5-4.5: 0.6-0.8, wherein the mass fraction of the sulfuric acid solution is 10-20 wt%.

Preferably, NaAlH is used in step S2₄The mass ratio of the powder material to the ultramicro carbon hole powder material Z is 1: 1.2-1.4.

Preferably, the heat preservation time in the step S2 is calculated according to the heat preservation time of 0.01 hour per gram of mixture.

Preferably, the mass ratio of the PEO-PPO-PEO triblock copolymer to the hydrochloric acid solution in the step S11 is 1 to (45-55), wherein the mass fraction of the hydrochloric acid solution is 10-20 wt%.

Preferably, the particle size of the powder X obtained in the step S12 is less than or equal to 100 μm.

Preferably, the protective gas in the step S13 is argon, the carbonization temperature of the powder Y is 1200-1500 ℃, and the carbonization time is calculated according to 0.05 hour of carbonization of each gram of powder Y.

Preferably, the drying temperature of the white massive solid in the step S12 is 350-450 ℃; the evaporation temperature in the step S13 is 65-90 ℃; the mass fraction of the hydrochloric acid solution in the step S14 is 10-20 wt%, the drying temperature is 200-300 ℃, and the drying time is calculated by taking the mass of the collected filtered substances in the step S14 as the total mass and drying the filtered substances for 0.1 hour per gram of the total mass.

More preferably, the grinding means is ball milling.

The invention provides the ultramicro carbon pore NaAlH prepared by the preparation method in the second aspect₄A hydrogen storage material product.

More preferably, the ultramicro carbon pore NaAlH₄The diameter of the ultramicro carbon pore powder Z in the hydrogen storage material product is less than 2 nm.

More preferably, NaAlH in step S2₄Powder and ultramicro carbon hole powder Z matterWhen the quantity ratio is 1: 1.2, the ultramicro carbon pore hydrogen storage NaAlH prepared in the step S3₄The first hydrogen release amount of the-C powder at 180 ℃ can reach 4.9 wt%.

The third aspect of the invention provides the ultramicro carbon pore NaAlH₄Use of a hydrogen storage material product in a hydrogen storage product.

More preferably, the ultramicro carbon pore hydrogen storage NaAlH prepared in the step S3₄the-C powder can be directly filled into a hydrogen storage tank for use, and the hydrogen storage density reaches 4.0 to 4.9 weight percent.

Compared with the prior art, the invention has the following beneficial effects:

(1) the method takes PEO-PPO-PEO triblock copolymer, diethyl carbonate and 1, 4-diacetylene benzene as carbon source precursors, and leads NaAlH to be heated in vacuum and kept warm₄After melting, dipping the mixture into a carbon pore channel of powder Z under the action of capillary adsorption, and finally performing ball milling and compounding to obtain the ultramicro carbon pore NaAlH₄A hydrogen storage material.

(2) The method can prepare the NaAlH with the carbon pore diameter less than 2 nm and ultramicro carbon pores₄the-C hydrogen storage material realizes further improvement of the hydrogen absorption and desorption performance of the existing hydrogen storage material. In one embodiment, it can be seen that the ultramicro carbon pore hydrogen storage NaAlH prepared by the invention₄The majority of carbon pores of-C have a pore size below 2 nm. In one of the examples, it can be seen that pure NaAlH₄The initial hydrogen release amount is about 0.5 wt% after 4200 s, and the ultramicro carbon pore hydrogen storage NaAlH prepared by the invention₄C increases the initial hydrogen evolution to 4.9 wt% under the same conditions. And the ultramicro carbon pore NaAlH prepared by the method of the invention₄The hydrogen storage material can keep higher stability in the hydrogen absorption and desorption circulation process. In one embodiment, the ultramicro carbon pore hydrogen storage NaAlH₄The reversible capacity retention rate of-C is still above 80% even after 15 hydrogen absorption and desorption cycles. The ultramicro carbon pore NaAlH₄The hydrogen storage material has remarkable hydrogen absorption and desorption performances, and can be attributed to two functions: in one aspect, a carbon material is reacted with NaAlH₄The catalyst has interaction and shows good catalytic effect; NaAlH, on the other hand₄And its dehydrogenated product is limited in ultramicro carbon of powder material ZIn the pore structure, the separation and diffusion of products are effectively prevented, the diffusion distance of hydrogen atoms is shortened, and the constructed ultramicro carbon pore NaAlH₄The hydrogen storage performance of the hydrogen storage material is far superior to that of pure NaAlH₄。

Drawings

FIG. 1 is a drawing showing NaAlH prepared in example 1 of the present invention, comparative examples 1 and 2₄XRD spectrogram of the hydrogen storage material;

FIG. 2 shows NaAlH prepared in example 1 and comparative example 2 of the present invention₄An infrared spectrum (FTIR) of the hydrogen storage material;

FIG. 3 shows the ultramicro carbon pore NaAlH prepared in example 1 of the present invention₄-C hydrogen storage material respectively releases hydrogen kinetic curve and hydrogen release enthalpy change at 150 ℃, 170 ℃, 180 ℃ and 190 ℃;

FIG. 4 shows the ultramicro carbon pore NaAlH prepared in example 1 of the present invention₄-C hydrogen storage material hydrogen storage cycling profile at 180 ℃;

FIG. 5 is a drawing showing NaAlH prepared in example 1 of the present invention, comparative examples 1 and 2₄Hydrogen evolution kinetics profile of hydrogen storage materials.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail by the following embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

Example 1

The embodiment of the invention provides a nano carbon pore NaAlH₄The preparation method of the hydrogen storage material comprises the following steps:

s1, preparing the ultramicro carbon pore powder Z, and specifically comprising the following operation steps: s11, dissolving 10 g of PEO-PPO-PEO triblock copolymer in 500 g of 15 wt% diluted hydrochloric acid, and standing at room temperature of 25 ℃ or uniformly stirring industrially to obtain colorless mixed liquid; s12, adding 5 g of diethyl carbonate, stirring uniformly at room temperature, standing, precipitating, filtering, washing, collecting filtrate, drying at 400 ℃ to obtain white block-shaped solid, and further grinding the white block-shaped solid in a ball mill to obtain powder X with the diameter of not more than 100 microns; s13, weighing powder X, uniformly mixing 1, 4-diacetylene benzene powder, 20 wt% of dilute sulfuric acid and the powder X according to the mass ratio of 1: 4: 0.6, obtaining a mixed solution after the powder X is completely dissolved, putting the mixed solution into a baking oven at the temperature of 75 ℃ for evaporation and drying until the powder Y is completely separated out, and then preserving the temperature of the powder Y under the argon atmosphere at the temperature of 1500 ℃ to carbonize the powder Y, wherein the preserving time is calculated according to 0.05 hour per gram; s14, adding the carbonized powder Y into excessive 10 wt% of dilute hydrochloric acid, stirring uniformly, standing, filtering to obtain a filtrate, washing the filtrate, and drying at 250 ℃, wherein the drying time is calculated according to 0.1 hour per gram, so as to obtain the ultramicro carbon hole powder Z.

S2, adding NaAlH₄Uniformly mixing the powder material and the ultramicro carbon hole powder material Z according to the mass ratio of 1: 1.2, putting the mixture into a closed container and vacuumizing the closed container; the vacuum vessel was held at a constant temperature of 190 ℃ for a period of time, calculated as 0.01 hour per gram.

S3, cooling the vacuum container, and mechanically grinding to obtain ultramicro carbon-pore hydrogen storage NaAlH₄-C powder.

The samples prepared in the above process were: ultramicro carbon pore NaAlH₄Hydrogen storage material (NaAlH)₄-C). The Transmission Electron Microscope (TEM) image is used for the nano-carbon pore NaAlH of the embodiment₄The characterization analysis of the hydrogen storage material sample shows that the pore diameter of most carbon pores is below 2 nm. FIG. 1 shows the ultramicro carbon pore NaAlH of this example₄Hydrogen storage material sample and NaAlH of comparative example 1₄Non-porous graphite hydrogen storage material sample and NaAlH of comparative example 2₄X-ray diffraction spectrum (XRD spectrum) of the hydrogen storage material sample, and NaAlH of the sample can be seen from the X-ray diffraction spectrum₄The phase characteristic peak is not obvious, and the phase structure of comparative example 1 and comparative example 2 is typical NaAlH₄Single phase structural characteristics, thus utilizing ultramicro carbon pore matrix to load NaAlH₄The composite hydrogen storage material is synthesized. FIG. 2 shows the ultramicro carbon pore NaAlH of this example₄Hydrogen storage material sample and NaAlH of comparative example 2₄Infrared spectrum (FT-IR spectrum) of a sample of hydrogen storage material, from which it can be seen that the sample was found to be associated with pure NaAlH₄At 1640-1680 cm^-1All contain Al-H bonds. FIG. 3 shows the ultramicro carbon pore NaAlH of this example₄The hydrogen storage material sample releases hydrogen kinetics curve and hydrogen release enthalpy change at 150 ℃, 170 ℃, 180 ℃ and 190 ℃, and the hydrogen release kinetics test process is as follows: the sample was placed under vacuum (initial vacuum 1X 10)^-3Torr) is heated to 150 ℃, 170 ℃, 180 ℃ and 190 ℃ respectively at the heating rate of 6 ℃/min and is kept warm, the hydrogen discharge performance test is carried out, and the curve result shows that the nano carbon pore NaAlH is ultra-micro₄The hydrogen storage material has a faster hydrogen discharge rate and a lower hydrogen discharge enthalpy, and the hydrogen discharge enthalpy becomes about 46 kJ/mol, which is about NaAlH₄1/3 for the enthalpy of hydrogen evolution. FIG. 4 shows the ultramicro carbon pore NaAlH of this example₄The hydrogen storage material sample releases hydrogen circulation curve chart at 180 ℃, and the hydrogen releasing process of hydrogen absorption and release circulation is as follows: under vacuum (initial vacuum degree 1X 10)^-3Torr) and respectively heating to 180 ℃ at the heating rate of 6 ℃/min and keeping the temperature for 50 min, and carrying out the isothermal hydrogen discharge reaction test. The hydrogen absorption process is as follows: under the hydrogen pressure of 80 bar, respectively heating to 180 ℃ at the heating rate of 6 ℃/min, preserving the heat for 1 h, and carrying out the isothermal hydrogen absorption reaction test. The results of the curves show that the first hydrogen release amount reaches 4.9 wt%, the fifth hydrogen absorption and release cycle hydrogen release amount reaches 4.6 wt%, and the fifteenth hydrogen absorption and release cycle hydrogen release amount reaches 4.0 wt%.

Example 2

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the amount of the PEO-PPO-PEO triblock copolymer added in the step S11 was 9 g.

Example 3

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the amount of the PEO-PPO-PEO triblock copolymer added in the step S11 was 11 g.

Example 4

Ultramicro carbon pore NaAlH₄Preparation of hydrogen storage materialsThe preparation method is basically the same as that of the embodiment 1, and the difference is that: in said step S11, the PEO-PPO-PEO triblock copolymer was dissolved in 450 g of dilute hydrochloric acid.

Example 5

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: in said step S11, the PEO-PPO-PEO triblock copolymer was dissolved in 550 g of dilute hydrochloric acid.

Example 6

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: in said step S11, the PEO-PPO-PEO triblock copolymer is dissolved in 10 wt% diluted hydrochloric acid.

Example 7

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: in said step S11, the PEO-PPO-PEO triblock copolymer is dissolved in 20 wt% diluted hydrochloric acid.

Example 8

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the drying temperature in the step S12 was 350 ℃.

Example 9

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the drying temperature in the step S12 was 450 ℃.

Example 10

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: in the step S13, the mass ratio of the 1, 4-diacetylene benzene powder, the dilute sulfuric acid to the powder X is 1: 3.5: 0.6.

Example 11

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the mass of the 1, 4-diacetylene benzene powder, the dilute sulfuric acid and the powder X in the step S13The ratio is 1: 4.5: 0.8.

Example 12

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the mass fraction of the dilute sulfuric acid added in the step S13 is 10 wt%.

Example 13

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the carbonization temperature of the powder Y in the step S13 is 1200 ℃.

Example 14

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the temperature of the evaporation drying in the oven in the step S13 was 65 ℃.

Example 15

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the temperature of the evaporation drying in the oven in the step S13 was 90 ℃.

Example 16

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: in the step S14, the powder Y is added to 20 wt% of dilute hydrochloric acid.

Example 17

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the drying temperature in the step S14 was 200 ℃.

Example 18

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the drying temperature in the step S14 was 300 ℃.

Example 19

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: in the step S2NaAlH₄The mass ratio of the powder material to the ultramicro carbon hole powder material Z is 1: 1.4.

Example 20

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: the vacuum vessel was incubated at 185 ℃ in step S2.

Example 21

Ultramicro carbon pore NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: in step S2, the vacuum container is maintained at 195 ℃.

Comparative example 1

NaAlH₄The contents of the preparation method of the non-porous graphite hydrogen storage material are basically the same as those of example 1, except that: without the preparation of step S1, NaAlH was directly added₄Mixing the powder with non-porous graphite powder, and ball-milling to obtain NaAlH₄-a non-porous graphite hydrogen storage material.

Comparative example 2

NaAlH₄The hydrogen storage material was prepared in substantially the same manner as in example 1, except that: preparation of step S1 was not performed, and only NaAlH was added₄Putting the powder into a closed container, vacuumizing and ball-milling to obtain pure NaAlH₄A hydrogen storage material.

And (3) performance testing:

the hydrogen evolution kinetics of the hydrogen storage materials prepared in example 1, comparative example 1 and comparative example 2 were measured by a volume method, and the prepared materials were subjected to vacuum conditions (initial vacuum degree of 1 × 10)^-3Torr) was added, the temperature was raised to 180 ℃ at a temperature raising rate of 6 ℃/min, and the temperature was maintained, and a hydrogen release performance test was carried out, the results of which are shown in FIG. 5.

As can be seen from FIG. 5, NaAlH added with ultrafine carbon pore powder Z₄The hydrogen discharging amount of the hydrogen storage material can reach 4.9 wt% after 4200 s at 180 ℃. And NaAlH₄Non-porous graphite and pure NaAlH₄The hydrogen storage material was subjected to a hydrogen discharge test at 180 ℃ and the results of the curve showed that the hydrogen discharge amount after 4200 s was 1.6 wt% and 0.5 wt%, respectively.

In conclusion, the present invention effectively overcomes the disadvantages of the prior art and has high industrial utilization value. The above-described embodiments are intended to illustrate the substance of the present invention, but are not intended to limit the scope of the present invention. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the invention.