High-performance solid hydrogen storage material and hydrogen energy electric bicycle with solid hydrogen as hydrogen source

Abstract

The invention discloses a high-performance solid hydrogen storage material and a hydrogen energy electric bicycle using solid hydrogen as a hydrogen source, and the hydrogen storage material is prepared by the following steps: mixing MgH2 powder, MgF2 powder, LiBH4 powder and a catalyst according to a mass ratio of MgH2: MgF2: LiBH4: catalyst = 45-65: 6-13: 18-30: 5-20, putting the mixture into a ball mill, carrying out ball milling for 4-10 h under the conditions of a ball-to-material ratio of (30-55): 1, argon protection and 300-650 rpm, and carrying out vacuum drying to obtain the high-performance solid hydrogen storage material. The high-performance solid hydrogen storage material is obtained. According to the invention, the MgH2 hydrogen storage alloy and the LiBH4 hydrogen storage alloy are compounded, and MgF2 and the metal oxide-carbon-based material composite catalyst are doped, so that the hydrogen storage capacity of the material can be improved, and the hydrogen desorption reaction temperature can be reduced. The hydrogen energy electric bicycle has the advantages of being safe, efficient, capable of saving energy, environmentally friendly and the like, and has wide application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen energy, and particularly relates to a high-performance solid hydrogen storage material and a hydrogen energy electric bicycle using solid hydrogen storage as the hydrogen source. Background Art

[0002] Electric vehicles are lightweight, have a moderate speed, are inexpensive, have no noise or exhaust pollution, and occupy a small parking space, which can greatly improve the traffic efficiency of non-motor vehicle lanes. They are very suitable for single-person short-distance travel within the city and have advantages that cannot be compared with other means of transportation. At present, the power storage of electric bicycles on the market is mainly borne by lead-acid batteries and lithium-ion batteries, both of which have problems such as short battery life, slow charging, difficult charging, and lifespan attenuation. In addition, lithium-ion batteries have certain safety hazards and the disadvantage of expensive replacement; while the pollution of lead-acid batteries and lithium batteries in the early and later stages is also a long-term environmental problem.

[0003] Hydrogen energy is considered an ideal clean energy source, with advantages such as light mass, rich reserves, and environmental friendliness. Solid hydrogen storage technology has characteristics such as high volumetric hydrogen storage density, low hydrogen storage pressure, and high safety, and has received wide attention and great potential for application in electric bicycles. For example, a battery-free composite solid hydrogen storage fuel cell electric bicycle provided by Patent CN114735128A, a hydrogen energy bicycle based on low-pressure solid hydrogen storage as the hydrogen source provided by Patent CN110606160B, etc.

[0004] Magnesium hydride (MgH 2 ) has a high hydrogen storage capacity (7.6 wt%), and magnesium resources are abundant, making it a promising solid hydrogen storage material. However, the thermodynamic stability of MgH 2 is too high, resulting in too high hydrogen absorption and desorption temperatures (above 300 °C), which severely restricts its practical application. LiBH 4 has a high hydrogen storage density, and the theoretical hydrogen storage density is about 18.5 wt%, which is much higher than that of magnesium hydride. The main defect is that the hydrogen desorption temperature is too high (exceeding 400 °C).

[0005] Therefore, it is necessary to improve the existing technology to provide a more reliable solution. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a high-performance solid hydrogen storage material and a hydrogen energy electric bicycle using solid hydrogen storage as the hydrogen source in view of the above deficiencies in the existing technology.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is: The present invention provides a high-performance solid hydrogen storage material, which is prepared by the following method:

[0008] Mix MgH 2 powder, MgF2 Powder, LiBH 4 The powder, MgH 2 : MgF 2 : LiBH 4 : catalyst = 45 - 65:6 - 13:18 - 30:5 - 20 are mixed in proportion and loaded into a ball mill with a ball-to-material ratio of 30 - 55:1, ball-milled for 4 - 10 h under argon protection at 300 - 650 rpm to obtain a high-performance solid-state hydrogen storage material.

[0009] Preferably, the high-performance solid-state hydrogen storage material is prepared by the following method: MgH 2 The powder, MgF 2 The powder, LiBH 4 The powder is sieved through a 200-mesh sieve and then mixed with the catalyst according to the mass ratio of MgH 2 : MgF 2 : LiBH 4 : catalyst = 55:8:25:12 are mixed in proportion and loaded into a ball mill with a ball-to-material ratio of 40:1, ball-milled for 6 h under argon protection at 550 rpm to obtain a high-performance solid-state hydrogen storage material; among them, the intermittent ball-milling mode is adopted, ball-milling for 25 min and stopping for 5 min.

[0010] Preferably, the catalyst is a metal oxide-carbon-based material composite catalyst, which is prepared by the following method:

[0011] 1) Pretreatment of graphene oxide;

[0012] 2) Preparation of porous cerium iron oxide microsphere-graphene oxide composite material;

[0013] 3) Preparation of reduced carbon dots;

[0014] 4) Using the porous cerium iron oxide microsphere-graphene oxide composite material and the reduced carbon dots, the metal oxide-carbon-based material composite catalyst is prepared by a one-pot hydrothermal reaction.

[0015] Preferably, the metal oxide-carbon-based material composite catalyst is prepared by the following method:

[0016] 1) Pretreatment of graphene oxide:

[0017] Graphene oxide is added to a mixed acid composed of 95 wt% concentrated sulfuric acid and 30 wt% hydrogen peroxide, soaked under ultrasonic treatment, filtered and dried to obtain pretreated graphene oxide;

[0018] 2) Preparation of porous cerium iron oxide microsphere-graphene oxide composite material;

[0019] 2-1) Add 0.25 - 0.9 g of the treated graphene oxide into 25 - 100 mL of deionized water, and ultrasonically disperse for 15 - 60 min;

[0020] 2-2) Take 0.325 - 1.3 g of cerium nitrate hexahydrate, 0.6 - 2.4 g of ferric nitrate nonahydrate, 35 - 140 mL of deionized water, and 15 - 60 mL of ethanol and add them into a container. After stirring for 5 - 30 min, add 0.85 - 3 g of polyvinylpyrrolidone, stir for 2 - 10 min, and then add the dispersion prepared in step 2-1) under stirring. Continue to stir for 10 - 45 min, and then transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner liner, and react at 160 - 200 °C for 8 - 20 h;

[0021] 2-3) After the reaction is completed, cool to room temperature, filter, wash successively with ethanol and deionized water, dry under vacuum, and then calcine in an air atmosphere at 420 - 550 °C for 1 - 4 h to obtain a porous cerium-iron oxide microsphere-graphene oxide composite material;

[0022] 3) Prepare reduced carbon dots:

[0023] 3-1) Weigh 384 - 1152 mg of citric acid, 142 - 568 mg of lutein, 117 - 468 mg of bipyridine, 54 - 216 mg of o-phenylenediamine, and 119 - 476 mg of titanium tetrachloride and add them into 125 - 500 mL of an ethanol aqueous solution. After ultrasonically dispersing for 15 - 60 min, transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner liner, and react at 180 - 210 °C for 3 - 12 h;

[0024] Among them, the ethanol aqueous solution is obtained by mixing ethanol and deionized water according to a volume ratio of 2:1 to 1:2;

[0025] 3-2) After the reaction is completed, cool to room temperature, filter with a filter membrane, and dialyze the filtrate in deionized water for 12 - 48 h using a dialysis bag with a molecular weight cut-off of 800 - 1200 Da. Collect the product inside the dialysis bag and freeze-dry to obtain reduced carbon dots;

[0026] 4) Take 0.5 - 2 g of the porous cerium-iron oxide microsphere-graphene oxide composite material prepared in step 2) and add it into a citric acid aqueous solution with a mass concentration of 1.5 - 6%. After soaking for 2 - 15 min, filter. Add the obtained solid product into 100 - 400 mL of deionized water, add 0.175 - 0.7 g of the reduced carbon dots prepared in step 3) under stirring, ultrasonically disperse for 30 - 90 min, transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner liner, react at 120 - 160 °C for 2.5 - 8 h, cool to room temperature, centrifuge and filter, wash the solid product with deionized water, and dry under vacuum to obtain the metal oxide-carbon-based material composite catalyst.

[0027] Preferably, step 1) is specifically as follows: 1 g of graphene oxide is added to 200 mL of a mixed acid composed of 95 wt% concentrated sulfuric acid and 30 wt% hydrogen peroxide in a volume ratio of 3:1, ultrasonicated at 60 °C for 2 h, filtered, the solid product is washed with deionized water until neutral, and vacuum dried at 80 °C for 12 h to obtain pretreated graphene oxide.

[0028] Preferably, step 2) is specifically as follows: 2-1) Take 0.45 g of the treated graphene oxide and add it to 50 mL of deionized water, and ultrasonically disperse for 30 min;

[0029] 2-2) Take 0.65 g of cerium nitrate hexahydrate, 1.2 g of ferric nitrate nonahydrate, 70 mL of deionized water, and 30 mL of ethanol and add them to a container. After stirring for 15 min, add 1.5 g of polyvinylpyrrolidone, stir for 5 min, and then add the dispersion prepared in step 2-1) under stirring. After continuing to stir for 20 min, transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner lining and react at 180 °C for 14 h;

[0030] 2-3) After the reaction is completed, cool to room temperature, filter, wash successively with ethanol and deionized water, vacuum dry at 60 °C for 12 h, and then calcine in an air atmosphere at 450 °C for 2 h to obtain a porous cerium-iron oxide microsphere-graphene oxide composite material.

[0031] Preferably, step 3) is specifically as follows:

[0032] 3-1) Weigh 768 mg of citric acid, 284 mg of lutein, 234 mg of bipyridine, 108 mg of o-phenylenediamine, and 238 mg of titanium tetrachloride and add them to 250 mL of an ethanol aqueous solution. After ultrasonic dispersion for 45 min, transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner lining and react at 190 °C for 6 h;

[0033] Among them, the ethanol aqueous solution is obtained by mixing ethanol and deionized water in a volume ratio of 1:1;

[0034] 3-2) After the reaction is completed, cool to room temperature, filter with a 0.22 μm filter membrane, dialyze the filtrate in deionized water with a dialysis bag with a molecular weight cut-off of 1000 Da for 24 h, collect the product inside the dialysis bag, and freeze-dry to obtain reduced carbon dots.

[0035] Preferably, step 4) is specifically as follows: Take 1 g of the porous cerium-iron oxide microsphere-reduced graphene oxide composite prepared in step 2) and add it to an aqueous citric acid solution with a mass concentration of 3%. After soaking for 10 min, filter. Add the obtained solid product to 200 mL of deionized water, add 0.35 g of the reduced carbon dots prepared in step 3) under stirring, and ultrasonically disperse for 45 min. Transfer the obtained mixture to a reaction kettle lined with polytetrafluoroethylene, react at 140 °C for 5 h, cool to room temperature, centrifuge and filter. Wash the solid product with deionized water and vacuum dry at 70 °C to constant weight to obtain the metal oxide-carbon-based material composite catalyst.

[0036] The present invention also provides a hydrogen energy electric bicycle using solid-state hydrogen storage as the hydrogen source, including a vehicle body, a hydrogen fuel cell system, and a drive system. The hydrogen fuel cell system uses the high-performance solid-state hydrogen storage alloy as described above to provide hydrogen to generate electric energy, and the drive system uses the electric energy provided by the hydrogen fuel cell system to provide driving force for the vehicle body.

[0037] Preferably, the hydrogen fuel cell system includes a hydrogen storage bottle filled with the high-performance solid-state hydrogen storage alloy as described above for providing hydrogen and a fuel cell for generating electric energy using hydrogen.

[0038] The beneficial effects of the present invention are:

[0039] The present invention provides a high-performance solid-state hydrogen storage material, which combines MgH 2 hydrogen storage alloy with LiBH 4 hydrogen storage alloy, and dopes MgF 2 and a metal oxide-carbon-based material composite catalyst. The high hydrogen storage density characteristic of the LiBH 4 hydrogen storage alloy can improve the hydrogen storage capacity of the material, while MgH 2 can change the stability of the dehydrogenation reaction product of LiBH 4 by acting with it, reduce the reaction enthalpy of formation, and thus lower the dehydrogenation reaction temperature; the doping of MgF 4 2 2 2 4 4 2 4 The addition of the metal oxide-carbon-based material composite catalyst can comprehensively improve the hydrogen absorption and desorption performance and the cycle stability performance of the MgH 2 4 composite hydrogen storage material system;

[0040] ​​​​The present invention further provides a hydrogen-powered electric bicycle based on the high-performance solid-state hydrogen storage material. The electric bicycle has the advantages of safety, high efficiency, energy conservation and environmental protection, can meet the market demand for green travel, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is the hydrogen desorption curve at a heating rate for the hydrogen storage materials prepared in Example 1 and Comparative Examples 1-7 under 0.1 MPa;

[0042] Figure 2 It is the hydrogen absorption curve for the hydrogen storage materials prepared in Example 1, Comparative Example 2, and Comparative Example 6 under 6 MPa;

[0043] Figure 3 It is the hydrogen desorption curve for the hydrogen storage materials prepared in Example 1, Comparative Example 2, and Comparative Example 6 at 350 °C and 0.1 MPa;

[0044] Figure 4 It is the test results of the initial hydrogen desorption temperature of the hydrogen storage materials prepared in Examples 1-4 and Comparative Examples 1-7;

[0045] Figure 5 It is the test results of the hydrogen storage density of the hydrogen storage materials prepared in Examples 1-4 and Comparative Examples 1-7;

[0046] Figure 6 It is the test results of the capacity retention rate of the hydrogen storage materials prepared in Examples 1-4 and Comparative Examples 1-7;

[0047] Figure 7 It is the infrared absorption spectrum of the reduced carbon dots Ti-CDs prepared in Example 1;

[0048] Figure 8 It is the XRD pattern of the metal oxide-carbon-based material composite catalyst prepared in Example 1;

[0049] Figure 9 It is the test results of the antioxidant performance of the reduced carbon dots Ti-CDs prepared in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0050] The present invention will be further described in detail below with reference to the embodiments, so that those skilled in the art can implement it according to the description in the specification.

[0051] It should be understood that the terms such as "having", "comprising" and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0052] Unless otherwise specified, the test methods used in the following examples are all conventional methods. Unless otherwise specified, the materials and reagents used in the following examples can all be obtained through commercial channels. For those not indicating specific conditions in the following examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0053] In the first aspect of the present invention, a high-performance solid-state hydrogen storage material is provided, which is prepared by the following method:

[0054] Mix MgH 2 powder, MgF 2 powder, LiBH 4 powder and a catalyst in a mass ratio of MgH 2 :MgF 2 :LiBH 4 :catalyst = 45 - 65:6 - 13:18 - 30:5 - 20, and load the mixture into a ball mill. The ball-to-material ratio is 30 - 55:1. Under argon protection, ball mill at 300 - 650 rpm for 4 - 10 h to obtain the high-performance solid-state hydrogen storage material.

[0055] In a preferred embodiment, the ball milling process is operated in an intermittent ball milling mode, with ball milling for 20 - 30 min and stopping for 5 - 10 min.

[0056] In a preferred embodiment, the metal oxide-carbon-based material composite catalyst is prepared by the following method:

[0057] 1) Pretreatment of graphene oxide:

[0058] Add graphene oxide into a mixed acid composed of 95 wt% concentrated sulfuric acid and 30 wt% hydrogen peroxide, soak and treat under ultrasonic waves, filter and dry to obtain pretreated graphene oxide;

[0059] 2) Preparation of porous cerium iron oxide microsphere-graphene oxide composite material;

[0060] 2-1) Take 0.25 - 0.9 g of the treated graphene oxide and add it to 25 - 100 mL of deionized water, and disperse it ultrasonically for 15 - 60 min;

[0061] 2-2) Take 0.325 - 1.3 g of cerium nitrate hexahydrate, 0.6 - 2.4 g of ferric nitrate nonahydrate, 35 - 140 mL of deionized water, 15 - 60 mL of ethanol and add them into a container. After stirring for 5 - 30 min, add 0.85 - 3 g of polyvinylpyrrolidone, stir for 2 - 10 min, and then add the dispersion prepared in step 2-1) under stirring. Continue to stir for 10 - 45 min, and then transfer the obtained mixture to a reaction kettle lined with polytetrafluoroethylene, and react at 160 - 200 °C for 8 - 20 h;

[0062] 2 - 3) After the reaction is completed, it is cooled to room temperature, filtered, washed successively with ethanol and deionized water, dried under vacuum, and then calcined in an air atmosphere at 420 - 550 °C for 1 - 4 h to obtain a porous cerium - iron oxide microsphere - graphene oxide composite material;

[0063] 3) Preparation of reduced carbon dots:

[0064] 3 - 1) Weigh 384 - 1152 mg of citric acid, 142 - 568 mg of lutein, 117 - 468 mg of bipyridine, 54 - 216 mg of o - phenylenediamine, and 119 - 476 mg of titanium tetrachloride, add them to 125 - 500 mL of an ethanol - aqueous solution, ultrasonically disperse for 15 - 60 min, then transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner lining, and react at 180 - 210 °C for 3 - 12 h;

[0065] Among them, the ethanol - aqueous solution is obtained by mixing ethanol and deionized water according to a volume ratio of 2:1 to 1:2;

[0066] 3 - 2) After the reaction is completed, it is cooled to room temperature, filtered with a filter membrane, and the filtrate is dialyzed in deionized water for 12 - 48 h using a dialysis bag with a cut - off molecular weight of 800 - 1200 Da. The product inside the dialysis bag is collected and freeze - dried to obtain reduced carbon dots;

[0067] 4) Take 0.5 - 2 g of the porous cerium - iron oxide microsphere - graphene oxide composite material prepared in step 2) and add it to a citric acid aqueous solution with a mass concentration of 1.5 - 6%. After soaking for 2 - 15 min, filter it. The obtained solid product is added to 100 - 400 mL of deionized water, and 0.175 - 0.7 g of the reduced carbon dots prepared in step 3) is added under stirring. Ultrasonically disperse for 30 - 90 min, transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner lining, react at 120 - 160 °C for 2.5 - 8 h, cool to room temperature, centrifuge and filter, wash the solid product with deionized water, and dry under vacuum to obtain a metal oxide - carbon - based material composite catalyst.

[0068] In the second aspect of the present invention, there is provided a hydrogen - energy electric bicycle using solid - state hydrogen storage as a hydrogen source, including a vehicle body, a hydrogen fuel cell system, and a drive system. The hydrogen fuel cell system uses the above - mentioned high - performance solid - state hydrogen storage alloy to provide hydrogen to generate electric energy, and the drive system uses the electric energy provided by the hydrogen fuel cell system to provide driving force for the vehicle body.

[0069] In a preferred embodiment, the hydrogen fuel cell system includes a hydrogen storage bottle filled with the above - mentioned high - performance solid - state hydrogen storage alloy for providing hydrogen and a fuel cell for generating electric energy using hydrogen.

[0070] In the present invention, MgH 2Hydrogen storage alloy and LiBH 4 The hydrogen storage alloy is compounded and doped with MgF 2 and a metal oxide-carbon based material composite catalyst. Through LiBH 4 The characteristic of high hydrogen storage density of the hydrogen storage alloy can improve the hydrogen storage capacity of the material, while MgH 2 can change LiBH 4 by acting on it 4 The stability of the dehydrogenation reaction product, reduce the reaction enthalpy of formation, and thus reduce the dehydrogenation reaction temperature; The doping of MgF 2 On the one hand, by forming a solid solution with MgH 2 can improve the dehydrogenation kinetic performance of MgH 2 On the other hand, it can further reduce the dehydrogenation temperature of LiBH 4 through the lattice substitution of F- for LiBH 4 ; The added metal oxide-carbon based material composite catalyst can simultaneously improve the hydrogen absorption and desorption performance and cycle stability performance of the MgH 2 and LiBH 4 composite hydrogen storage material system; Finally, the prepared high-performance solid-state hydrogen storage alloy has both high hydrogen storage capacity, excellent cycle stability and good hydrogen absorption and desorption performance, and has great potential for application in hydrogen energy electric vehicles, hydrogen energy vehicles and other fields. The principle of the present invention is described in more detail below for better understanding of the present invention.

[0071] MgH 2 The hydrogen storage alloy has a relatively high hydrogen storage capacity (theoretical hydrogen storage density is 7.6 wt%), rich resources and low price, and is a very promising hydrogen storage material, but it also has some defects, including: high dehydrogenation temperature, slow hydrogen absorption and desorption reaction rate, poor cycle stability, etc.

[0072] MgH 2 The dehydrogenation reaction of is:

[0073] MgH 2 →Mg + H 2

[0074] LiBH 4 has a high hydrogen storage density, and the theoretical hydrogen storage density is about 18.5 wt%. The main defect is that the dehydrogenation temperature is too high (exceeding 400 °C), and its dehydrogenation reaction is:

[0075] LiBH 4 →LiH + B + H 2

[0076] (1) Adding MgH 2 has been proven to be able to change LiBH4 decomposition pathway, thus changing the stability of the reaction products, reducing the enthalpy of formation of the reaction, and ultimately effectively reducing the dehydrogenation temperature of LiBH 4 , and the main reactions involved are as follows (John, J, Vajo, et al. Reversible Storage of Hydrogen in Destabilized LiBH4[J]. The Journal of Physical Chemistry B, 2005, 109(9):3719–3722. DOI:10.1021 / jp040769o.):

[0077] 2LiBH 4 +MgH 2 →2LiH+MgB 2 +H 2

[0078] (2) After MgF 2 is doped into the material system, on the one hand, it can be solid-soluted into MgH 2 . During the dehydrogenation heating process, MgF 2 precipitates from MgH 2 , causing the lattice parameter to change, resulting in the instability and fracture of the Mg-H bond, thereby promoting the dehydrogenation reaction of MgH 2 (Zhang Jian. Hydrogen Storage Performance of Novel Catalyst Ball-Milled Doped Magnesium Hydride [D]. South China University of Technology, 2013.); on the other hand, the F- introduced by MgF 2 can enter the lattice of LiBH 4 to form a substitution structure of LiBH 1-x F x . Due to the ionic radius difference between F- and H-, LiBH 1-x F x can provide more reaction active centers and hydrogen atom diffusion channels than LiBH 4 , thereby being able to further reduce the dehydrogenation temperature of LiBH 4 (Wang Xinhua, Xu Lou, Wu Xiaocheng, et al. Influence of Ce-Based Catalysts on the Dehydrogenation Performance of 2LiBH4 / MgH2 [J]. Rare Metal Materials and Engineering, 2011(011):040.). It can be seen that the doping of MgF 2 can effectively improve the dehydrogenation kinetic performance of both MgF 2 and LiBH 4 .

[0079] (3) The catalyst in the present invention is a metal oxide-carbon-based material composite catalyst, which is obtained by modifying carbon dots with reducibility on a graphene oxide composite material in-situ grafted with porous cerium-iron oxide microspheres, and it can significantly improve the hydrogen absorption and desorption performance and cyclic stability of MgF 2 and LiBH 4 .

[0080] I. Preparation mechanism:

[0081] First, graphene oxide is pretreated with a mixed acid to increase the functional groups such as carboxyl groups on its surface, facilitating subsequent modification; then, using polyvinylpyrrolidone as a surfactant, through hydrothermal reaction combined with high-temperature calcination, a composite microsphere of cerium dioxide and iron(III) oxide with a porous structure is in-situ grafted on the pretreated graphene oxide, that is, a porous cerium-iron oxide microsphere-graphene oxide composite material CeFeO@GO is obtained;

[0082] After that, using citric acid 3, lutein, bipyridine as carbon sources, o-phenylenediamine as a nitrogen source, and titanium tetrachloride as a doping component, a titanium-doped reduced carbon dot Ti-CDs with good reduction performance is prepared through hydrothermal reaction;

[0083] Finally, through a one-pot hydrothermal reaction, the reduced carbon dots are modified onto the porous cerium-iron oxide microsphere-graphene oxide composite material to obtain the final metal oxide-carbon-based material composite catalyst Ti-CDs@CeFeO@GO. In this step, by soaking the porous cerium-iron oxide microsphere-graphene oxide composite material with dilute acid (citric acid), a large number of metal ions (Ce4+, Fe3+) can be generated on its surface, and through the combination of these metal ions with the carboxyl, hydroxyl and other functional groups on the surface of the reduced carbon dots, the reduced carbon dots are attached to the porous cerium-iron oxide microsphere-graphene oxide composite material in large quantities, and then through hydrothermal reaction, stable chemical bonds are formed to achieve firm grafting, and finally a ternary composite structural system of "reduced carbon dots + porous cerium-iron oxide microspheres + graphene oxide" is constructed: Ti-CDs@CeFeO@GO.

[0084] II. Action mechanism

[0085] A. The role of porous cerium-iron oxide

[0086] Cerium dioxide has excellent catalytic characteristics for hydrogen absorption and desorption of hydrogen storage materials. This catalytic performance mainly depends on the variable valence characteristics of cerium ions and the oxygen vacancy concentration that changes with the valence change of cerium ions (Zhang Guofang, Zhai Tingting, Hou Zhonghui, et al. Nano CeO 2Research on the Influence of the Spectral Characteristics of -xNx Solid Solution on Its Catalytic Performance[J]. Spectroscopy and Spectral Analysis, 2018, 38(10): 7. DOI: 10.3964 / j.issn.1000-0593(2018)10-3192-07.)

[0087] The porous cerium-iron oxide (iron(III) oxide doped with cerium dioxide) microspheres have a rich mesoporous structure, which can enhance the physical adsorption hydrogen storage capacity of the material; and they have a high specific surface area, enabling more active sites to be exposed on the material surface, providing a richer channel for the diffusion of hydrogen, thus facilitating the improvement of the hydrogen absorption and desorption performance; during the ball milling process, it can also play a role in assisting the milling.

[0088] As a transition metal oxide, iron(III) oxide can play a role in reducing the hydrogen absorption and desorption temperature of hydrogen storage materials such as MgF 2 and improving the hydrogen absorption and desorption kinetic performance (Yao Zhang, Shouquan Li, Tiao Ying, et al. Influence of Ball Milling Surface Coating on the Electrochemical Performance of Magnesium-Based Hydrogen Storage Alloys[J]. The Chinese Journal of Nonferrous Metals, 2001, 11(004): 582-586. DOI: 10.3321 / j.issn:1004-0609.2001.04.010.).

[0089] On the other hand, the doping of nickel and iron metals and the doping of titanium in carbon dots can improve the dispersion performance of graphene oxide in the hydrogen storage alloy material system and promote its uniform mixing with the hydrogen storage alloy material system.

[0090] B. The Role of Graphene Oxide

[0091] By attaching to the surface of the hydrogen storage alloy material, graphene oxide can enhance its specific surface area and lubrication effect. During the ball milling process, the surface of graphene oxide breaks into irregular flakes, generating more edge positions and hydrogen channels, thus improving the hydrogen storage performance of the material (Yankun Wang, Xusheng Liu, Yuping Chen, et al. High energy ball milling composite modification of Mg 2 Ni hydrogen storage alloy by graphene and MWCNTs[J]. International journal of hydrogen energy, 50(2024)1562–1573.). In addition, graphene oxide has a high thermal conductivity and can form a heat conduction network in the system, improving the thermal conductivity and thermal uniformity of the material; while the excellent mechanical properties of graphene oxide can reduce the pulverization of the hydrogen storage alloy material during use and improve its cyclic stability performance.

[0092] C. Role of titanium-cerium doped carbon dots

[0093] Both lutein and bipyridine in the raw materials for preparing the carbon dots of the present invention have good reduction properties, and the carbon dots also well inherit this characteristic, and can provide antioxidant properties in the hydrogen storage material system, and can effectively avoid the oxidation of MgF 2 and LiBH 4 , thereby significantly improving the cycle stability of the hydrogen storage material.

[0094] Titanium doped with carbon dots has a catalytic promoting effect on the hydrogen release process of the hydrogen storage alloy, can improve the activation performance, and improve the service life of the material (Hu Sumei. Research on the Hydrogen Storage Performance of Magnesium-based Carbon Nanotube Composites [D]. Lanzhou University of Technology, 2009. DOI: 10.7666 / d.y1464595.).

[0095] In addition, during the ball milling process, the ball milling action will damage the oxide layer on the surface of the alloy. As a kind of nanocarbon material, carbon dots have good reducibility, enabling them to react with the oxide layer and / or prevent the formation of a new oxide layer, thus improving the activation performance of the alloy (Wu Junqing, Zhou Shixue, Yang Minjian, etc. Hydrogen Storage Function of Carbon Materials [J]. Coal Science and Technology, 2006, 34(11): 4. DOI: 10.3969 / j.issn.0253-2336.2006.11.025.).

[0096] Furthermore, the small size, high specific surface area of the carbon dots, and the abundant surface functional groups capable of interacting with hydrogen molecules can provide a large number of active sites for adsorbing hydrogen, thereby enhancing the physical hydrogen storage capacity; at the same time, the carbon dots have excellent electron transfer performance and can increase the electron density, which is conducive to catalytically promoting the hydrogen absorption and release reactions.

[0097] The present invention further provides an application scenario with good potential based on this high-performance solid-state hydrogen storage material, such as a hydrogen energy electric bicycle; of course, this high-performance solid-state hydrogen storage material also has the potential to be applied in many other scenarios such as hydrogen fuel cell vehicles, distributed power supply, large batteries, and standby power supplies. It should be understood that when applying this high-performance solid-state hydrogen storage material to scenarios such as hydrogen energy electric bicycles and hydrogen fuel cell vehicles, a corresponding thermal management system needs to be configured to provide the temperature environment required for hydrogen release. However, since the hydrogen release temperature of the material in the present invention has dropped significantly, the requirements for the thermal management system are lower, which is more conducive to its application.

[0098] The above is the overall concept of the present invention. The following provides detailed examples and comparative examples on this basis to further illustrate the present invention.

[0099] Example 1

[0100] A high-performance solid-state hydrogen storage material is prepared by the following method: MgH 2 powder, MgF 2 powder, LiBH 4 powder is sieved through a 200-mesh sieve and then mixed with a catalyst according to the mass ratio of MgH 2 :MgF 2 :LiBH 4 :catalyst = 55:8:25:12, and the mixture is loaded into a ball mill with a ball-to-material ratio of 40:1. Under argon protection and at 550 rpm, ball milling is carried out for 6 h to obtain the high-performance solid-state hydrogen storage material; among them, an intermittent ball milling method is adopted, with ball milling for 25 min and stopping for 5 min.

[0101] In this embodiment, the catalyst is a metal oxide-carbon-based material composite catalyst, which is prepared by the following method:

[0102] 1) Pretreatment of graphene oxide:

[0103] Add 1 g of graphene oxide (flake graphene oxide, with a thickness range of 0.5 - 1 nm and a sheet diameter range of 2 - 5 μm, purchased from Suzhou Kaifa New Material Technology Co., Ltd., the same in the following examples and comparative examples) to 200 mL of a mixed acid composed of 95 wt% concentrated sulfuric acid and 30 wt% hydrogen peroxide in a volume ratio of 3:1. Ultrasonic treatment is carried out at 60 °C for 2 h, followed by filtration. The solid product is washed with deionized water until neutral and then vacuum dried at 80 °C for 12 h to obtain the pretreated graphene oxide.

[0104] 2) Preparation of porous cerium iron oxide microsphere-graphene oxide composite:

[0105] 2-1) Take 0.45 g of the treated graphene oxide and add it to 50 mL of deionized water, and ultrasonically disperse for 30 min;

[0106] 2-2) Take 0.65 g of cerium nitrate hexahydrate, 1.2 g of ferric nitrate nonahydrate, 70 mL of deionized water, 30 mL of ethanol and add them to a container. After stirring for 15 min, add 1.5 g of polyvinylpyrrolidone and stir for 5 min. Then, add the dispersion prepared in step 2-1) under stirring and continue to stir for 20 min. After that, transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner lining and react at 180 °C for 14 h;

[0107] 2-3) After the reaction is completed, cool to room temperature, filter, wash successively with ethanol and deionized water, vacuum dry at 60 °C for 12 h, and then calcine in an air atmosphere at 450 °C for 2 h to obtain the porous cerium iron oxide microsphere-graphene oxide composite.

[0108] 3) Preparation of reduced carbon dots:

[0109] 3-1) Weigh 768 mg of citric acid, 284 mg of lutein, 234 mg of bipyridine, 108 mg of o-phenylenediamine, and 238 mg of titanium tetrachloride, add them to 250 mL of an ethanol aqueous solution, ultrasonically disperse for 45 min, then transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner liner, and react at 190 °C for 6 h;

[0110] Among them, the ethanol aqueous solution is obtained by mixing ethanol and deionized water according to a volume ratio of 1:1;

[0111] 3-2) After the reaction is completed, cool to room temperature, filter with a 0.22-μm filter membrane, dialyze the filtrate in deionized water with a dialysis bag with a molecular weight cut-off of 1000 Da for 24 h, collect the product inside the dialysis bag, and freeze-dry to obtain reduced carbon dots.

[0112] 4) Using the porous cerium iron oxide microsphere-graphene oxide composite material and the reduced carbon dots, a metal oxide-carbon-based material composite catalyst is prepared by a one-pot hydrothermal reaction:

[0113] Take 1 g of the porous cerium iron oxide microsphere-graphene oxide composite material prepared in step 2) and add it to a citric acid aqueous solution with a mass concentration of 3%, soak for 10 min and then filter. Add the obtained solid product to 200 mL of deionized water, add 0.35 g of the reduced carbon dots prepared in step 3) under stirring, ultrasonically disperse for 45 min, transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner liner, react at 140 °C for 5 h, cool to room temperature, centrifuge and filter, wash the solid product with deionized water, and vacuum dry at 70 °C to constant weight to obtain the metal oxide-carbon-based material composite catalyst.

[0114] Example 2

[0115] A high-performance solid-state hydrogen storage material is prepared by the following method: Pass the MgH 2 powder, MgF 2 powder, and LiBH 4 powder through a 200-mesh sieve and then mix them with the catalyst according to a mass ratio of MgH 2 :MgF 2 :LiBH 4 :catalyst = 55:9:25:11, load them into a ball mill, with a ball-to-material ratio of 40:1, under argon protection and ball mill at 550 rpm for 6 h to obtain the high-performance solid-state hydrogen storage material; among them, an intermittent ball milling method is adopted, ball mill for 25 min and stop for 5 min.

[0116] Example 3

[0117] A high-performance solid-state hydrogen storage material is prepared by the following method: Pass the MgH 2 powder, MgF 2 powder, and LiBH4 After the powder passes through a 200-mesh sieve, it is mixed with the catalyst according to the mass ratio of MgH 2 :MgF 2 :LiBH 4 :catalyst = 55:10:25:10, and the mixture is loaded into a ball mill. The ball-to-material ratio is 40:1. Under argon protection and at 550 rpm, ball milling is carried out for 6 h to obtain a high-performance solid-state hydrogen storage material. Among them, an intermittent ball milling method is adopted, with ball milling for 25 min and stopping for 5 min.

[0118] Example 4

[0119] A high-performance solid-state hydrogen storage material is prepared by the following method: Mix MgH 2 powder, MgF 2 powder, LiBH 4 powder. After passing through a 200-mesh sieve, it is mixed with the catalyst according to the mass ratio of MgH 2 :MgF 2 :LiBH 4 :catalyst = 55:8:25:12, and the mixture is loaded into a ball mill. The ball-to-material ratio is 35:1. Under argon protection and at 500 rpm, ball milling is carried out for 8 h to obtain a high-performance solid-state hydrogen storage material. Among them, an intermittent ball milling method is adopted, with ball milling for 25 min and stopping for 5 min.

[0120] Example 5

[0121] A hydrogen energy electric bicycle using solid-state hydrogen storage as the hydrogen source includes a vehicle body, a hydrogen fuel cell system, and a drive system. The hydrogen fuel cell system uses the high-performance solid-state hydrogen storage alloy of Example 1 to provide hydrogen to generate electric energy, and the drive system uses the electric energy provided by the hydrogen fuel cell system to provide driving force for the vehicle body.

[0122] Among them, the hydrogen fuel cell system includes a hydrogen storage bottle filled with the high-performance solid-state hydrogen storage alloy of Example 1 for providing hydrogen and a fuel cell for generating electric energy using hydrogen.

[0123] Comparative Example 1

[0124] A high-performance solid-state hydrogen storage material is prepared by the following method: Mix MgH 2 powder, LiBH 4 powder. After passing through a 200-mesh sieve, it is mixed with the catalyst according to the mass ratio of MgH 2 :LiBH 4 :catalyst = 55:25:12, and the mixture is loaded into a ball mill. The ball-to-material ratio is 40:1. Under argon protection and at 550 rpm, ball milling is carried out for 6 h to obtain a high-performance solid-state hydrogen storage material. Among them, an intermittent ball milling method is adopted, with ball milling for 25 min and stopping for 5 min.

[0125] The catalyst in this example is the same as that in Example 1.

[0126] Comparative Example 2

[0127] A high-performance solid-state hydrogen storage material is prepared by the following method: After passing MgH 2 powder, MgF 2 powder, and LiBH 4 powder through a 200-mesh sieve, they are mixed in a mass ratio of MgH 2 :MgF 2 :LiBH 4 = 55:8:25, loaded into a ball mill, with a ball-to-material ratio of 40:1, ball-milled for 6 h under argon protection at 550 rpm to obtain a high-performance solid-state hydrogen storage material; among them, the intermittent ball-milling method is adopted, ball-milling for 25 min and stopping for 5 min.

[0128] Comparative Example 3

[0129] This example is basically the same as Example 1, except that:

[0130] The catalyst in this example is the porous cerium-iron oxide microsphere-graphene oxide composite material in Example 1.

[0131] Comparative Example 4

[0132] This example is basically the same as Example 1, except that:

[0133] The catalyst is prepared by the following method:

[0134] 1) Pretreatment of graphene oxide, the same as in Example 1;

[0135] 2) Preparation of porous cerium-iron oxide microsphere-graphene oxide composite material, the same as in Example 1;

[0136] 3) Preparation of reduced carbon dots:

[0137] 3-1) Weigh 768 mg of citric acid, 284 mg of lutein, 234 mg of bipyridine, and 108 mg of o-phenylenediamine, add them to 250 mL of an ethanol aqueous solution, ultrasonically disperse for 45 min, and then transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner liner, and react at 190 °C for 6 h;

[0138] Among them, the ethanol aqueous solution is obtained by mixing ethanol and deionized water in a volume ratio of 1:1;

[0139] 3-2) After the reaction is completed, cool to room temperature, filter with a 0.22-μm filter membrane, dialyze the filtrate in deionized water with a dialysis bag with a molecular weight cut-off of 1000 Da for 24 h, collect the product in the dialysis bag, and freeze-dry to obtain reduced carbon dots.

[0140] 4) Take 1 g of the porous cerium-iron oxide microsphere-reduced graphene oxide composite prepared in step 2) and add it to an aqueous citric acid solution with a mass concentration of 3%. After soaking for 10 min, filter. Add the obtained solid product to 200 mL of deionized water. While stirring, add 0.35 g of the reduced carbon dots prepared in step 3). Ultrasonically disperse for 45 min. Transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner liner, react at 140 °C for 5 h, cool to room temperature, centrifuge and filter. Wash the solid product with deionized water and vacuum dry at 70 °C until constant weight to obtain the catalyst.

[0141] Comparative Example 5

[0142] This example is basically the same as Example 1, except that:

[0143] The catalyst is prepared by the following method:

[0144] 1) Pretreat the reduced graphene oxide, which is the same as in Example 1;

[0145] 2) Prepare the porous oxide microsphere-reduced graphene oxide composite:

[0146] 2-1) Take 0.45 g of the treated reduced graphene oxide and add it to 50 mL of deionized water. Ultrasonically disperse for 30 min;

[0147] 2-2) Take 1.2 g of ferric nitrate nonahydrate, 70 mL of deionized water, and 30 mL of ethanol and add them to a container. After stirring for 15 min, add 1.5 g of polyvinylpyrrolidone and stir for 5 min. Then, while stirring, add the dispersion prepared in step 2-1). Continue to stir for 20 min and then transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner liner. React at 180 °C for 14 h;

[0148] 2-3) After the reaction, cool to room temperature, filter, wash successively with ethanol and deionized water, vacuum dry at 60 °C for 12 h, and then calcine in an air atmosphere at 450 °C for 2 h to obtain the porous oxide microsphere-reduced graphene oxide composite.

[0149] 3) Prepare the reduced carbon dots, which is the same as in Example 1;

[0150] 4) Take 1 g of the porous oxide microsphere-reduced graphene oxide composite prepared in step 2) and add it to an aqueous citric acid solution with a mass concentration of 3%. After soaking for 10 min, filter. Add the obtained solid product to 200 mL of deionized water. While stirring, add 0.35 g of the reduced carbon dots prepared in step 3). Ultrasonically disperse for 45 min. Transfer the obtained mixture to a reaction kettle with a polytetrafluoroethylene inner liner, react at 140 °C for 5 h, cool to room temperature, centrifuge and filter. Wash the solid product with deionized water and vacuum dry at 70 °C until constant weight to obtain the catalyst.

[0151] Comparative Example 6

[0152] This example is basically the same as Example 1, except that:

[0153] The catalyst in this example is a mixture composed of pre-treated graphene oxide and reduced carbon dots with a mass ratio of 10:3.5.

[0154] Among them, the pre-treated graphene oxide is the same as that in Example 1, and the reduced carbon dots are also the same as those in Example 1.

[0155] Comparative Example 7

[0156] This example is basically the same as Example 1, except that:

[0157] The catalyst in this example is a mixture composed of porous cerium-iron oxide microsphere-graphene oxide composite and reduced carbon dots with a mass ratio of 10:3.5.

[0158] Among them, the porous cerium-iron oxide microsphere-graphene oxide composite is the same as that in Example 1, and the reduced carbon dots are also the same as those in Example 1.

[0159] Performance Test and Characterization

[0160] 1. The hydrogen storage density and hydrogen absorption / desorption performance were tested using an H-Sorb 2600 fully automatic PCT hydrogen storage material tester.

[0161] 2. The cyclic stability test was carried out with 40 complete hydrogen absorption / desorption cycles at 350 °C (hydrogen desorption pressure 0.1 MPa, hydrogen absorption pressure 6 MPa). The hydrogen storage capacity (hydrogen storage density) was measured, and then the capacity retention rate was calculated. The capacity retention rate = (hydrogen storage capacity after multiple cycles / initial hydrogen storage capacity) × 100%.

[0162] The test results are shown in Table 1 below and Figures 1-6 as follows:

[0163] Table 1

[0164]

[0165]

[0166] Figure 1 is the hydrogen desorption curve during heating at 0.1 MPa for the hydrogen storage materials prepared in Example 1 and Comparative Examples 1-7, Figure 2 is the hydrogen absorption curve at 6 MPa for the hydrogen storage materials prepared in Example 1, Comparative Example 2, and Comparative Example 6, Figure 3 is the hydrogen desorption curve at 350 °C and 0.1 MPa for the hydrogen storage materials prepared in Example 1, Comparative Example 2, and Comparative Example 6, Figures 4-6The test results of the initial hydrogen desorption temperature, hydrogen storage density, and capacity retention rate of the hydrogen storage materials prepared in Examples 1-4 and Comparative Examples 1-7 are shown in sequence.

[0167] According to Table 1, Figure 1 and Figures 4-6 it can be seen from the test results that the hydrogen storage materials prepared in Examples 1-4 have a lower hydrogen desorption temperature, a higher hydrogen storage density, and excellent cycle stability performance, with excellent comprehensive performance. In Comparative Example 1, MgF was not doped 2 , resulting in a significant increase in its initial hydrogen desorption temperature; in Comparative Example 2, due to the absence of a doped catalyst, the initial hydrogen desorption temperature increased significantly, and the cycle stability performance (capacity retention rate) decreased significantly; the reason for the increase in the initial hydrogen desorption temperature and the decrease in the cycle stability performance in Comparative Example 3 is that the reduced carbon dots were not grafted in the catalyst; the changes in the initial hydrogen desorption temperature and capacity retention rate in Comparative Example 4 can illustrate the role of titanium doping of reduced carbon dots; the results of Comparative Example 5 can illustrate the promoting effect of cerium doping on the hydrogen desorption performance of porous cerium-iron composite oxide microspheres; in Comparative Example 6, all performances decreased, attributed to the absence of doped porous cerium-iron composite oxide microspheres in the catalyst; the decrease in all performances in Comparative Example 7 indicates that the effect of constructing the ternary composite structure system Ti-CDs@CeFeO@GO of "reduced carbon dots + porous cerium-iron oxide microspheres + graphene oxide" is better than the scheme of directly blending and adding the composite material of reduced carbon dots and porous cerium-iron oxide microspheres-graphene oxide.

[0168] According to Figure 2 and Figure 3 the results, it can be seen that the hydrogen absorption and desorption kinetic performance of Example 1 is significantly better than that of Comparative Example 2 and Comparative Example 6.

[0169] In order to further illustrate the mechanism of the metal oxide-carbon-based material composite catalyst in the present invention, taking Example 1 as an example, the following performance characterization tests are carried out.

[0170] (1) Referring to Figure 7 , it is the infrared absorption spectrum of the reduced carbon dots Ti-CDs prepared in Example 1. It can be seen that the surface of the carbon dots has rich functional groups such as carboxyl, hydroxyl, and amino groups, and the appearance of the characteristic peak of the Ti-O bond indicates the successful doping of Ti.

[0171] (2) Referring to Figure 8 , it is the XRD pattern of the metal oxide-carbon-based material composite catalyst prepared in Example 1. Through the pattern, it can be shown that the catalyst was successfully synthesized.

[0172] (3) The following method is used to test the antioxidant performance of the reduced carbon dots (Ti-CDs) prepared in Example 1:

[0173] The reduced carbon dots prepared in Example 1 were prepared into a dispersion with a concentration of 0.5 mg / mL using ethanol, and then the antioxidant properties of the dispersion at different times were tested using a DPPH free radical scavenging ability test kit (provided by Hefei Laier Biotechnology Co., Ltd.).

[0174] Determination principle: DPPH free radical has a single electron, its alcohol solution is purple, and has strong absorption at 515nm. When there is an antioxidant, the DPPH free radical is scavenged, the color becomes lighter, and the absorbance at 515nm decreases. Within a certain range, the change in absorbance is proportional to the degree of free radical scavenging, that is, the lower the absorbance at 515nm, the stronger the nitrogen free radical scavenging ability and the stronger the antioxidant performance.

[0175] Reference Figure 9 , is the test result, it can be seen that the reduced carbon dots have good reduction performance.

[0176] (4) The BET specific surface area of ​​the metal oxide-carbon-based material composite catalyst prepared in Example 1 was measured using a BET specific surface area analyzer and was 283 m 2 / g.

[0177] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A high-performance solid-state hydrogen storage material, characterized in that: It is prepared by the following method: MgH2 powder, MgF2 powder, LiBH4 powder and catalyst are mixed in a ball mill in a mass ratio of MgH2:MgF2:LiBH4:catalyst = 45-65:6-13:18-30:5-20, with a ball-to-material ratio of 30-55:1, and ball milled at argon protection at 300-650rpm for 4-10 hours to obtain a high-performance solid hydrogen storage material.

2. The high performance solid hydrogen storage material according to claim 1, characterized in that: The material is prepared by the following method: MgH2 powder, MgF2 powder and LiBH4 powder are passed through a 200-mesh sieve and mixed with a catalyst in a mass ratio of MgH2:MgF2:LiBH4:catalyst = 55:8:25:12, and then loaded into a ball mill with a ball-to-material ratio of 40:

1. The material is ball-milled at 550 rpm for 6 hours under argon protection to obtain a high-performance solid hydrogen storage material; wherein, an intermittent ball milling mode is adopted, with ball milling for 25 minutes and stopping for 5 minutes.

3. The high performance solid hydrogen storage material according to claim 1 or 2, characterized in that: The catalyst is a metal oxide-carbon-based material composite catalyst, which is prepared by the following method: 1) Graphene oxide pretreatment; 2) preparing porous cerium iron oxide microsphere-graphene oxide composite materials; 3) Preparation of reduced carbon dots; 4) The metal oxide-carbon-based material composite catalyst is prepared by a one-pot hydrothermal reaction using porous cerium iron oxide microspheres-graphene oxide composite material and reduced carbon dots.

4. The high performance solid hydrogen storage material according to claim 3, characterized in that: The metal oxide-carbon-based material composite catalyst is prepared by the following method: 1) Graphene oxide pretreatment: The graphene oxide is added into a mixed acid consisting of 95 wt % concentrated sulfuric acid and 30 wt % hydrogen peroxide, and is soaked under ultrasound, filtered, and dried to obtain pretreated graphene oxide; 2) preparing porous cerium iron oxide microsphere-graphene oxide composite materials; 2-1) adding 0.25-0.9 g of the treated graphene oxide into 25-100 mL of deionized water and performing ultrasonic dispersion for 15-60 min; 2-2) 0.325-1.3 g of cerium nitrate hexahydrate, 0.6-2.4 g of ferric nitrate nonahydrate, 35-140 mL of deionized water, and 15-60 mL of ethanol are added to a container, stirred for 5-30 min, 0.85-3 g of polyvinyl pyrrolidone is added, stirred for 2-10 min, and then the dispersion prepared in step 2-1) is added under stirring, stirring is continued for 10-45 min, and the resulting mixture is transferred to a polytetrafluoroethylene-lined reactor, and reacted at 160-200° C. for 8-20 h; 2-3) After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with ethanol and deionized water in sequence, vacuum dried, and then calcined in an air atmosphere at 420-550° C. for 1-4 h to obtain a porous cerium iron oxide microsphere-graphene oxide composite material; 3) Preparation of reduced carbon dots: 3-1) Weigh 384-1152 mg of citric acid, 142-568 mg of lutein, 117-468 mg of bipyridine, 54-216 mg of o-phenylenediamine, and 119-476 mg of titanium tetrachloride, add them into 125-500 mL of ethanol aqueous solution, and transfer the obtained mixture into a polytetrafluoroethylene-lined reactor after ultrasonic dispersion for 15-60 min, and react at 180-210° C. for 3-12 h; The ethanol aqueous solution is obtained by mixing ethanol and deionized water in a volume ratio of 2:1 to 1:2; 3-2) After the reaction is completed, the mixture is cooled to room temperature and filtered through a filter membrane. The filtrate is dialyzed in deionized water for 12-48 h using a dialysis bag with a molecular weight cutoff of 800-1200 Da. The product in the dialysis bag is collected and freeze-dried to obtain reduced carbon dots; 4) 0.5-2 g of the porous cerium iron oxide microsphere-graphene oxide composite material prepared in step 2) is added to a citric acid aqueous solution with a mass concentration of 1.5-6%, and the mixture is filtered after being soaked for 2-15 min. The obtained solid product is added to 100-400 mL of deionized water, and 0.175-0.7 g of the reduced carbon dots prepared in step 3) is added under stirring. The mixture is ultrasonically dispersed for 30-90 min. The obtained mixture is transferred to a polytetrafluoroethylene-lined reactor, reacted at 120-160° C. for 2.5-8 h, cooled to room temperature, centrifuged, and the solid product is washed with deionized water and vacuum dried to obtain the metal oxide-carbon-based material composite catalyst.

5. The high performance solid hydrogen storage material according to claim 4, characterized in that: Step 1) is specifically as follows: 1 g of graphene oxide is added to 200 mL of a mixed acid consisting of 95 wt% concentrated sulfuric acid and 30 wt% hydrogen peroxide in a volume ratio of 3:1, ultrasonically treated at 60°C for 2 h, filtered, the solid product is washed with deionized water until neutral, and vacuum dried at 80°C for 12 h to obtain pretreated graphene oxide.

6. The high performance solid hydrogen storage material according to claim 4, characterized in that: Step 2) is specifically as follows: 2-1) 0.45 g of the treated graphene oxide is added into 50 mL of deionized water and ultrasonically dispersed for 30 min; 2-2) 0.65 g of cerium nitrate hexahydrate, 1.2 g of ferric nitrate nonahydrate, 70 mL of deionized water, and 30 mL of ethanol were added to a container, stirred for 15 min, 1.5 g of polyvinyl pyrrolidone was added, stirred for 5 min, and then the dispersion prepared in step 2-1) was added under stirring, and the mixture was transferred to a polytetrafluoroethylene-lined reactor after stirring for 20 min, and reacted at 180° C. for 14 h; 2-3) After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with ethanol and deionized water in sequence, dried in vacuum at 60° C. for 12 h, and then calcined at 450° C. for 2 h in an air atmosphere to obtain a porous cerium iron oxide microsphere-graphene oxide composite material.

7. The high performance solid hydrogen storage material according to claim 4, characterized in that: Step 3) is specifically: 3-1) 768 mg of citric acid, 284 mg of lutein, 234 mg of bipyridine, 108 mg of o-phenylenediamine, and 238 mg of titanium tetrachloride were weighed and added to 250 mL of ethanol aqueous solution. After ultrasonic dispersion for 45 min, the resulting mixture was transferred to a polytetrafluoroethylene-lined reactor and reacted at 190° C. for 6 h. The ethanol aqueous solution is obtained by mixing ethanol and deionized water in a volume ratio of 1:1; 3-2) After the reaction is completed, the mixture is cooled to room temperature and filtered with a 0.22 μm filter membrane. The filtrate is dialyzed in deionized water for 24 h using a dialysis bag with a molecular weight cutoff of 1000 Da. The product in the dialysis bag is collected and freeze-dried to obtain reduced carbon dots.

8. The high performance solid hydrogen storage material according to claim 4, characterized in that: Step 4) is specifically as follows: 1 g of the porous cerium iron oxide microsphere-graphene oxide composite material prepared in step 2) is added to a citric acid aqueous solution with a mass concentration of 3%, and the mixture is filtered after being soaked for 10 min. The obtained solid product is added to 200 mL of deionized water, and 0.35 g of the reduced carbon dots prepared in step 3) is added under stirring. The mixture is ultrasonically dispersed for 45 min. The obtained mixture is transferred to a polytetrafluoroethylene-lined reactor, reacted at 140° C. for 5 h, cooled to room temperature, centrifuged, and the solid product is washed with deionized water. The solid product is vacuum dried at 70° C. to constant weight to obtain the metal oxide-carbon-based material composite catalyst.

9. A hydrogen-powered electric bicycle using solid-state hydrogen storage as a hydrogen source, comprising a vehicle body, a hydrogen fuel cell system and a drive system, wherein the hydrogen fuel cell system utilizes the high-performance solid-state hydrogen storage alloy described in any one of claims 1 to 8 to provide hydrogen to generate electrical energy, and the drive system utilizes the electrical energy provided by the hydrogen fuel cell system to provide driving force for the vehicle body.

10. The hydrogen-powered electric bicycle based on solid-state hydrogen storage as a hydrogen source according to claim 9, characterized in that: The hydrogen fuel cell system includes a hydrogen storage bottle for providing hydrogen, which is filled with the high-performance solid hydrogen storage alloy as described in any one of claims 1 to 8, and a fuel cell for generating electrical energy using hydrogen.

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