Preparation method of semi-metal antimony doped high specific surface area carbon supported scandium monatomic solid hydrogen storage material

Abstract

A preparation method of a semi-metallic antimony-doped high-specific-surface-area carbon-supported scandium monatomic solid hydrogen storage material comprises the following steps: fully mixing Sb2O4 and porous carbon, heating to 900 DEG C for calcination under the protection of nitrogen atmosphere, then cooling to room temperature under the protection of nitrogen atmosphere to obtain an antimony-doped high-specific-surface-area carbon material, adding deionized water, mixing and fully stirring, and carrying out vacuum drying to obtain the scandium monatomic solid hydrogen storage material supported by semi-metallic antimony-doped high-specific-surface-area carbon. The antimony-doped high-specific-surface-area carbon material dispersion liquid is obtained; and adding the antimony-doped high-specific-surface-area carbon material dispersion liquid into a scandium chloride solution while stirring, then adding deionized water to obtain a semi-metal antimony-doped carbon-supported scandium monatomic precursor liquid, standing at room temperature, removing supernate, retaining precipitate, and carrying out high-temperature pyrolysis to obtain the semi-metal antimony-doped high-specific-surface-area carbon-supported scandium monatomic solid hydrogen storage material. The method has the advantages that the process is simple, and high-efficiency hydrogen adsorption and rapid dynamic response are realized by utilizing the structural advantages of the bimetallic atoms and the high-specific-surface-area carbon material.

Description

Technical Field

[0001] The present invention relates to the field of solid-state hydrogen storage materials, and more specifically, to a method for preparing a semi-metallic antimony-doped high-specific-surface-area carbon-supported scandium single-atom solid-state hydrogen storage material. Background Art

[0002] As a clean energy carrier, hydrogen energy has become a new direction for energy transformation and sustainable energy development. Hydrogen has attracted much attention in energy storage and transportation due to its high energy density and zero emissions, but the storage of hydrogen is the main technical obstacle to its widespread application. Traditional gaseous or liquid hydrogen storage technology is limited by its safety issues and low energy efficiency. Therefore, solid-state hydrogen storage technology has become the main direction of hydrogen storage technology research due to its high safety and high volume hydrogen storage density.

[0003] Solid-state hydrogen storage technology mainly stores hydrogen in solid materials through physical adsorption or chemical adsorption. Solid-state hydrogen storage can not only effectively reduce the risk of hydrogen leakage, but also achieve high-density hydrogen storage under lower pressure and temperature conditions, significantly improving the transportation and application efficiency of hydrogen energy.

[0004] Among many solid-state hydrogen storage materials, carbon materials have been widely studied and applied as hydrogen storage media due to their high specific surface area, light weight, low cost, easy preparation and good chemical stability. However, physically adsorbed pure carbon materials produce weak van der Waals interactions with hydrogen molecules, resulting in unsatisfactory performance in hydrogen adsorption kinetics and cyclic stability, making them unsuitable for direct use as solid-state hydrogen storage materials. Summary of the invention

[0005] The technical problem to be solved by the present invention is to propose a method for preparing a semi-metallic antimony-doped high specific surface area carbon-supported scandium single atom solid hydrogen storage material. The method has a simple process and utilizes the structural advantages of bimetallic atoms and high specific surface area carbon materials to achieve high-efficiency hydrogen adsorption and rapid kinetic response.

[0006] The technical solution of the present invention is:

[0007] A method for preparing a semi-metallic antimony-doped high specific surface area carbon-supported scandium single atom solid hydrogen storage material, the specific steps of which are:

[0008] S1 Preparation of Antimony-doped Carbon Materials with High Specific Surface Area

[0009] Sb2O4 and porous carbon were fully mixed in a mass ratio of 1.5:8, heated to 900°C for calcination for 3 hours under the protection of a nitrogen atmosphere, and then cooled to room temperature under the protection of a nitrogen atmosphere to obtain an antimony-doped high specific surface area carbon material;

[0010] S2 Preparation of antimony-doped high specific surface area carbon material dispersion

[0011] Mix the antimony-doped high specific surface area carbon material with deionized water at a mass ratio of 1:200 and stir well to obtain a dispersion of the antimony-doped high specific surface area carbon material;

[0012] S3. Prepare a scandium chloride solution

[0013] Mix ScCl3·6H2O with deionized water at a mass ratio of 1:30 - 1:35 uniformly and stir well to obtain a scandium chloride solution; S4. Prepare a precursor solution of scandium single atoms supported by semi-metal antimony-doped carbon

[0014] Add the dispersion of the antimony-doped high specific surface area carbon material to the scandium chloride solution with stirring according to the mass ratio of the porous carbon in the antimony-doped high specific surface area carbon material to ScCl3·6H2O in the scandium chloride solution being 10:1, and then add deionized water with a volume ratio of 3:2 to the dispersion of the antimony-doped high specific surface area carbon material to obtain a precursor solution of scandium single atoms supported by semi-metal antimony-doped carbon;

[0015] S5. Prepare a preliminary product of the scandium single atom material supported by semi-metal antimony-doped carbon

[0016] Let the precursor solution of the scandium single atom material supported by semi-metal antimony-doped carbon stand at room temperature, remove the supernatant, retain the precipitate, and wash it with deionized water ≥3 times to obtain a preliminary product of the scandium single atom material supported by semi-metal antimony-doped carbon;

[0017] S6. High-temperature pyrolysis

[0018] Dry the preliminary product of the scandium single atom material supported by semi-metal antimony-doped carbon in vacuum at 200°C to obtain a scandium single atom solid hydrogen storage material supported by semi-metal antimony-doped high specific surface area carbon.

[0019] Furthermore, the vacuum drying time is 12 - 15 hours.

[0020] Furthermore, in step S3, ScCl3·6H2O and deionized water are in a mass ratio of 1:31.25.

[0021] Furthermore, when heating ScCl3·6H2O and deionized water in step S1, the heating rate is 10°C / min.

[0022] Furthermore, the stirring speed in step S4 is 50 revolutions per minute and the stirring time is 8 hours.

[0023] Furthermore, the specific surface area of the porous carbon is 2000 - 2100m 2 g -1 .

[0024] Furthermore, the standing time is 10 - 12 hours.

[0025] The present invention uses Sb2O4 as a precursor and high specific surface area carbon as the main material. Through heating in a tube furnace under a nitrogen atmosphere, an antimony-loaded porous carbon material is obtained. Then, a scandium chloride solution is added, followed by stirring, washing, and drying to obtain a scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon. The beneficial effects are as follows:

[0026] (1) Ultra-large specific surface area: The solid hydrogen storage material prepared by the present invention has a specific surface area as high as 2451 m 2 g -1 , providing a large number of active adsorption sites for hydrogen storage, effectively improving the hydrogen storage capacity and efficiency.

[0027] (2) High-efficiency hydrogen adsorption ability: By using high specific surface area carbon as the main material and combining the loading of antimony and scandium atoms, the solid hydrogen storage material prepared by the present invention reaches 800 cm 3 g -1 in terms of nitrogen adsorption and desorption amount, significantly exceeding the adsorption amount of traditional high specific surface area carbon, and achieving high-efficiency hydrogen adsorption.

[0028] (3) Good dispersibility and adsorption activity: Antimony and scandium particles have good dispersibility on high specific surface area carbon, avoiding the reduction of adsorption activity caused by particle agglomeration, and further improving the hydrogen adsorption ability of the material.

[0029] (4) Excellent hydrogen storage performance: At the liquid nitrogen temperature of 77 K, the solid hydrogen storage material prepared by the present invention exhibits excellent hydrogen absorption and desorption performance, with the hydrogen absorption and desorption amount reaching 4.62 wt%, far higher than that of similar materials, providing new possibilities for the field of solid hydrogen storage.

[0030] In summary, the process of the present invention is simple. The prepared solid hydrogen storage material makes full use of the structural advantages of bimetallic atoms and high specific surface area carbon materials, realizes high-efficiency hydrogen adsorption and rapid kinetic response, effectively improves the performance of the solid hydrogen storage material, and provides strong support for realizing efficient and reversible solid hydrogen storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the nitrogen adsorption-desorption isotherm curve of the high specific surface area carbon calcined by the present invention (corresponding to Comparative Example 1);

[0032] Figure 2 is the nitrogen adsorption-desorption isotherm curve of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon of the present invention (corresponding to Example 1);

[0033] Figure 3 is the pore size distribution diagram of the high specific surface area carbon calcined by the present invention (corresponding to Comparative Example 1);

[0034] Figure 4 is the pore size distribution diagram of the scandium single-atom material of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid-state hydrogen storage material of the present invention (corresponding to Example 1);

[0035] Figure 5 is the X-ray diffraction pattern of the high specific surface area carbon obtained by calcination of the present invention (corresponding to Comparative Example 1);

[0036] Figure 6 is the X-ray diffraction pattern of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid-state hydrogen storage material of the present invention (corresponding to Example 1);

[0037] Figure 7 is the hydrogen adsorption-desorption isotherm curve diagram of the high specific surface area carbon obtained by calcination of the present invention (corresponding to Comparative Example 1) at liquid nitrogen temperature;

[0038] Figure 8 is the hydrogen adsorption-desorption isotherm curve diagram of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid-state hydrogen storage material of the present invention (corresponding to Example 1) at liquid nitrogen temperature;

[0039] Figure 9 is the adsorption rate time-pressure curve diagram of the high specific surface area carbon obtained by calcination of the present invention (corresponding to Comparative Example 1);

[0040] Figure 10 is the adsorption rate time-pressure curve diagram of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid-state hydrogen storage material of the present invention (corresponding to Example 1);

[0041] Figure 11 is the scanning electron microscope images of the high specific surface area carbon obtained by calcination of the present invention (corresponding to Comparative Example 1) at different scales (a. 20μm; b. 5μm; c. 1μm);

[0042] Figure 12 is the scanning electron microscope images of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid-state hydrogen storage material of the present invention (corresponding to Example 1) at different scales (a. 20μm; b. 5μm; c. 1μm);

[0043] Figure 13 is the high-resolution (a. 100nm; b. 50nm; c. 10nm) images of the high specific surface area carbon obtained by calcination of the present invention (corresponding to Comparative Example 1);

[0044] Figure 14 is the high-resolution photos of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid-state hydrogen storage material of the present invention (corresponding to Example 1) at different scales (a. 100nm; b. 50nm; c. 10nm);

[0045] Figure 15 This is a scanning electron microscope image of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single atom solid hydrogen storage material of the present invention (corresponding to Example 1);

[0046] Figure 16 It is an energy spectrum analysis diagram of the corresponding element distribution of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single atom solid hydrogen storage material of the present invention (corresponding to Example 1);

[0047] Figure 17 It is the full X-ray photoelectron spectrum of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid hydrogen storage material of the present invention (corresponding to Example 1) and the corresponding element percentage diagram (Cl: 0.22at%; C: 99.25at%; Sc: 0.25at%; Sb: 0.28at%);

[0048] Figure 18 These are spherical aberration electron microscopy images of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid hydrogen storage material of the present invention (corresponding to Example 1) at different scales (a. 5 nm; c. 2 nm). DETAILED DESCRIPTION

[0049] The porous carbon used in Example 1 and Comparative Examples 1 to 4 of the present invention is porous carbon from the same batch.

[0050] Example 1

[0051] (1) Preparation of antimony-doped high specific surface area carbon

[0052] 1.5g of antimony oxide Sb2O4 and 8g of porous carbon (specific surface area of ​​2000-2100m 2 g -1 ) are fully mixed, placed in a tube furnace, heated to 900° C. at a rate of 10° C. / min in a nitrogen atmosphere, and calcined for 3 hours, and then cooled to room temperature under the protection of a nitrogen atmosphere to obtain an antimony-doped high specific surface area carbon material;

[0053] (2) Preparation of antimony-doped high specific surface area carbon material dispersion

[0054] 1 g of antimony-doped high specific surface area carbon material was mixed with 200 mL of deionized water in a beaker and stirred thoroughly to obtain an antimony-doped high specific surface area carbon material dispersion;

[0055] (3) Preparation of scandium chloride solution

[0056] Take 0.8 g of ScCl3·6H2O and mix with 25 mL of deionized water and stir thoroughly to obtain a scandium chloride solution;

[0057] (4) Preparation of semi-metallic antimony-doped carbon-supported scandium single atom precursor solution

[0058] Place a magnetic stirrer in the beaker containing the dispersion of antimony-doped high specific surface area carbon material prepared in step (2), and stir for 8 hours at a stirring rate of 50 revolutions per minute; and slowly and evenly add all the scandium chloride solution prepared in step (3) to the beaker during the stirring process, and add 300 mL of deionized water to the beaker to obtain a semi-metallic antimony-doped carbon-supported scandium single-atom precursor solution;

[0059] (5) Prepare the initial product of the semi-metallic antimony-doped carbon-supported scandium single-atom material

[0060] Let the semi-metallic antimony-doped carbon-supported scandium single-atom precursor solution stand at room temperature for 12 hours, remove the supernatant, retain the precipitate, and wash it 3 times with deionized water to obtain the initial product of the semi-metallic antimony-doped carbon-supported scandium single-atom precursor solution material;

[0061] (6) High-temperature pyrolysis

[0062] Place the initial product of the semi-metallic antimony-doped carbon-supported scandium single-atom precursor solution material in a vacuum oven and vacuum dry it at 200 °C for 12 hours to obtain a semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid hydrogen storage material.

[0063] The nitrogen adsorption and desorption capacity of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid hydrogen storage material of Example 1 is as Figure 2 shown, and it can be seen from Figure 2 that this material has a relatively high nitrogen adsorption and desorption capacity, close to 800 cm 3 g -1 , and a relatively large specific surface area, up to 2451 m 2 g -1 ; the pore distribution diagram of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid hydrogen storage material of Example 1 is as Figure 4 shown, and this material has a mesoporous and microporous structure; the X-ray diffraction pattern of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid hydrogen storage material of Example 1 is as Figure 6 shown, indicating that the doping of metallic antimony and scandium hardly affects the basic structure of the carbon material;

[0064] In the structural characterization of the material, the scanning electron microscope images of the semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid hydrogen storage material of Example 1 at different magnifications are as Figure 12 shown, and it can be observed from Figure 12 (a), (b), and (c) that some pore structures are filled with antimony and scandium atoms, making the surface of the material partially smooth, and there are also a large number of fine pore structures, indicating that while the loading of antimony and scandium increases the pore structure of the high specific surface area carbon, it does not significantly change the morphology structure and size distribution of the carbon; from Figure 14(a), (b), (c) It can be seen that the scandium single-atom structure supported by semi-metallic antimony-doped carbon is also pore-shaped distributed, and no large nanoparticles are observed; Scanning electron microscopy of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon in Example 1 Figure 15 And energy spectrum analysis of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon in Example 1 Figure 16 Indicates that antimony and scandium atoms are evenly distributed on the surface and pores of the high specific surface area carbon material, forming highly dispersed antimony and scandium atomic clusters; X-ray photoelectron spectroscopy of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon in Example 1 Figure 17 Confirms the successful introduction of antimony and scandium elements. Among them, the doping content of scandium element is 0.25 at%; the doping content of antimony element is 0.28 at%; The aberration-corrected electron microscopy images of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon in Example 1 at different scales are as Figure 18 Shown, from Figure 18 It can be observed that the dispersed scandium single atoms are evenly anchored on the antimony-doped high specific surface area carbon support.

[0065] In the hydrogen storage performance test of the material, the adsorption / desorption isotherm curve of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon in Example 1 at liquid nitrogen temperature (77 K) is as Figure 8 Shown, from Figure 8 It can be seen that the hydrogen adsorption / desorption amount of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon in Example 1 is 4.62 wt%, and when the pressure is 9.8 Pa, the hydrogen adsorption amount reaches 3.91 wt%. The adsorption rate and time-pressure curve of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon in Example 1 are as Figure 10 Shown, Figure 10 It shows that for the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon in Example 1, when hydrogen is adsorbed at 5 hours, the pressure reaches 50 Pa, and dehydrogenation only takes 3 hours, which is faster than the hydrogen adsorption / desorption rate of high specific surface area carbon.

[0066] Comparative Example 1: Undoped high specific surface area carbon material (high specific surface area carbon obtained by calcination): This example is basically the same as Example 1, except that antimony and scandium elements are not doped into the high specific surface area carbon.

[0067] Put 8 g of porous carbon (specific surface area 2000 - 2100 m 2 g -1 ) into a tube furnace, and under a nitrogen atmosphere, heat it to 900 °C at a rate of 10 °C / min and calcine for 3 hours, then cool it to room temperature under the protection of a nitrogen atmosphere to obtain an undoped high specific surface area carbon material;

[0068] The hydrogen storage material of high specific surface area carbon obtained by calcination of Comparative Example 1 was characterized by structure. It was found that Figure 3 The pore distribution diagram of the high specific surface area carbon shows that the material is a carbon material with mesoporous and microporous structures. The scanning electron microscope images of the high specific surface area carbon obtained by calcination of Comparative Example 1 at different magnifications are as shown in Figure 11 Shown as Figure 11 (a), (b), and (c). It can be seen that the high specific surface area carbon presents a blocky amorphous morphology. The length of the larger particles is about 8 - 10 microns, and there are blocky particles with a size of less than 7 microns around them. Its surface is relatively smooth, and there are a large number of tiny pores distributed on it. This structure has a relatively large specific surface area. The high-resolution transmission electron microscope images of the high specific surface area carbon obtained by calcination at different scales are as shown in Figure 13 Shown as Figure 13 (a), (b), and (c). It can be observed that the microstructure of the high specific surface area carbon obtained by calcination consists of many mesopores.

[0069] The high specific surface area carbon obtained by calcination of Comparative Example 1 was tested for performance. Its nitrogen adsorption - desorption amount is as shown in Figure 1 Shown as. The nitrogen adsorption - desorption amount of the high specific surface area carbon is 670 cm 3 g -1 , and its specific surface area is 2139 m 2 g -1 ; The adsorption - desorption isotherm curve of the high specific surface area carbon obtained by calcination of Comparative Example 1 at liquid nitrogen temperature (77K) is as shown in Figure 7 Shown as Figure 7 . It can be seen that this material shows a hydrogen adsorption - desorption amount of up to 4.4 wt% for the high specific surface area carbon, and the hydrogen adsorption - desorption curves basically coincide with those of the high specific surface area carbon obtained by calcination of Comparative Example 1; The time - pressure curve of the high specific surface area carbon obtained by calcination of Comparative Example 1 is as shown in Figure 9 Shown as Figure 9 . It can be seen from this that the pressure of the high specific surface area carbon reaches 50.1 Pa when hydrogen absorption occurs at 5.9 hours, and it takes 4.3 hours for dehydrogenation.

[0070] The comparison results of the parallel experiments between Example 1 and Comparative Example 1 show that the doping of antimony and scandium increases the specific surface area of the high specific surface area carbon, provides more active sites, and enables more hydrogen to be effectively adsorbed and stored. Moreover, the doping of antimony and scandium makes the antibonding orbitals formed by the metal sites in an incompletely filled state, which makes it easier for them to interact with H2 molecules, overcome the kinetic energy barrier of hydrogen absorption, and thus makes it easier for the scandium single - atom material supported by semi - metal antimony - doped carbon to store hydrogen.

[0071] Preparation method of scandium single - atom solid - state hydrogen storage material supported by semi - metal antimony - doped high specific surface area carbon under high - temperature pyrolysis in Comparative Example 2:

[0072] Change the temperature of the vacuum oven in step (6) of Example 1 from 200 °C to 500 °C, and keep other steps the same as in Example 1, to obtain a scandium single-atom solid-state hydrogen storage material supported by semi-metallic antimony-doped high-specific-surface-area carbon under high-temperature pyrolysis.

[0073] In Comparative Example 2, the scandium single-atom solid-state hydrogen storage material supported by semi-metallic antimony-doped high-specific-surface-area carbon under high-temperature pyrolysis undergoes partial aggregation and sintering, forming larger particles. The scandium single-atom solid-state hydrogen storage material supported by semi-metallic antimony-doped high-specific-surface-area carbon under high-temperature pyrolysis reaches only 3.78 wt% of the hydrogen absorption and desorption amount in the hydrogen absorption and desorption isothermal test at liquid nitrogen temperature (77 K).

[0074] The parallel test comparison results of Example 1 and Comparative Example 2 show that pyrolysis at too high a temperature will cause the doped metal nanoparticles to aggregate or sinter, resulting in a reduction in the specific surface area and active sites of the material, thereby weakening its hydrogen adsorption performance. Moreover, the aggregated metal particles may form longer or more complex diffusion paths, making the diffusion of hydrogen molecules inside the material more difficult. This will affect the rates of the hydrogen absorption and desorption processes.

[0075] Comparative Example 3 Low-temperature calcination of a scandium single-atom solid-state hydrogen storage material supported by semi-metallic antimony-doped high-specific-surface-area carbon

[0076] Change the heating of antimony oxide Sb2O4 and porous carbon in step (1) of Example 1 to 300 °C in a tube furnace, and keep other steps the same as in Example 1, to obtain a scandium single-atom solid-state hydrogen storage material supported by semi-metallic antimony-doped high-specific-surface-area carbon under low-temperature calcination.

[0077] For the scandium single-atom solid-state hydrogen storage material supported by semi-metallic antimony-doped high-specific-surface-area carbon under low-temperature calcination in Comparative Example 3, according to the X-ray photoelectron spectroscopy diagram, the doping content of scandium element is 0.27 at%; the doping content of antimony element is 0.12 at%; among them, the scandium single-atom solid-state hydrogen storage material supported by semi-metallic antimony-doped high-specific-surface-area carbon under low-temperature calcination reaches only 3.77 wt% of the hydrogen absorption and desorption amount in the hydrogen absorption and desorption isothermal test at liquid nitrogen temperature (77 K).

[0078] The parallel test comparison results of Example 1 and Comparative Example 3 show that when the calcination temperature of antimony oxide Sb2O4 and porous carbon is reduced to 300 °C, the diffusion rate of antimony will be greatly reduced, resulting in antimony possibly not being able to fully enter the pores and surface layer of the carbon material, thereby affecting the doping rate, reducing the activity of the surface functional groups of the material, and finally affecting the overall hydrogen storage performance of the material. Therefore, it is necessary to set the pyrolysis temperature to 900 °C during the antimony doping of high-specific-surface-area carbon, which realizes more uniform doping of antimony atoms on the surface of the carbon material.

[0079] Comparative Example 4 Preparation of a scandium single-atom material supported by silicon-doped high-specific-surface-area carbon:

[0080] (1) Preparation of silicon-doped high specific surface area carbon

[0081] Mix 1.5 g of tetraethyl orthosilicate (C8H 20 O4Si) and 8 g of porous carbon (specific surface area of 2000 - 2100 m 2 g -1 ) thoroughly, place it in a tube furnace, under a nitrogen atmosphere, heat it to 900 °C at a rate of 10 °C / min and calcine for 3 hours, then cool it to room temperature under the protection of a nitrogen atmosphere to obtain a silicon-doped high specific surface area carbon material;

[0082] (2) Preparation of a dispersion of silicon-doped high specific surface area carbon

[0083] Take 1 g of the silicon-doped high specific surface area carbon material and mix it with 200 mL of deionized water in a beaker and stir thoroughly to obtain a dispersion of the silicon-doped high specific surface area carbon material;

[0084] (3) Preparation of scandium chloride solution

[0085] Take 0.8 g of ScCl3·6H2O and mix it with 25 mL of deionized water and stir thoroughly to obtain a scandium chloride solution;

[0086] (4) Preparation of a precursor solution of scandium single atoms supported on silicon-doped carbon

[0087] Place a magnetic stirrer in the beaker containing the dispersion of the silicon-doped high specific surface area carbon material prepared in step (2), stir at a stirring rate of 50 revolutions per minute for 8 hours; and slowly and uniformly add all of the scandium chloride dispersion solution prepared in step (3) to the beaker during stirring, and add 300 mL of deionized water to the beaker to obtain a precursor solution of scandium single atoms supported on silicon-doped carbon;

[0088] (5) Preparation of a preliminary product of scandium single atom material supported on silicon-doped carbon

[0089] Let the precursor solution of scandium single atoms supported on silicon-doped carbon stand at room temperature for 12 hours, remove the supernatant, retain the precipitate, and wash it 3 times with deionized water to obtain a preliminary product of scandium single atom material supported on doped carbon;

[0090] (6) Pyrolysis

[0091] Place the preliminary product of scandium single atom material supported on doped carbon in a vacuum oven and vacuum dry it at 200 °C for 12 hours to obtain a scandium single atom material supported on silicon-doped high specific surface area carbon.

[0092] The scandium single atom material supported on silicon-doped high specific surface area carbon of Comparative Example 4 was subjected to structural characterization, and its specific surface area was obtained as 1843 m 2 g -1. The successful introduction of silicon and scandium elements was confirmed by X-ray photoelectron spectroscopy test; among them, the scandium doping content was 1.07at%; the silicon doping content was 0.75at%. Comparative Example 4 prepared a silicon-doped high specific surface area carbon-supported scandium single atom material. The performance test showed that the adsorption and desorption of hydrogen at liquid nitrogen temperature (77K) only reached 3.68wt%. After analysis, it may be that the silicon atoms enhance the interaction between the particles and the lattice, making it easier for the particles to form clusters, resulting in a reduction in specific surface area, which in turn affects the hydrogen storage performance of the material.

[0093] Comparative Example 5 Preparation of Scandium Single Atom Material Doped with High Specific Surface Area Carbon Support

[0094] (1) Preparation of nitrogen-doped high specific surface area carbon

[0095] 1.5g melamine C3H6N6 and 8g porous carbon (specific surface area 2000-2100m 2 g -1 ) are fully mixed, placed in a tube furnace, heated to 900° C. at a rate of 10° C. / min in a nitrogen atmosphere, and calcined for 3 hours, and then cooled to room temperature under the protection of a nitrogen atmosphere to obtain an antimony-doped high specific surface area carbon material;

[0096] (2) Preparation of nitrogen-doped high specific surface area carbon dispersion

[0097] 1 g of nitrogen-doped high specific surface area carbon material was mixed with 200 mL in a beaker and stirred thoroughly to obtain a nitrogen-doped high specific surface area carbon material dispersion;

[0098] (3) Preparation of scandium chloride solution

[0099] Take 0.8 g of ScCl3·6H2O and mix with 25 mL of deionized water and stir thoroughly to obtain a scandium chloride solution;

[0100] (4) Preparation of nitrogen-doped carbon-supported scandium single atom precursor solution

[0101] A magnetic stirrer was placed in the beaker containing the nitrogen-doped high specific surface area carbon material dispersion prepared in step (2), and the stirring time was 8 hours at a stirring rate of 50 rpm; and all the scandium chloride solution prepared in step (3) was slowly and evenly added to the beaker during the stirring process, and 300 mL of deionized water was added to the beaker to obtain a nitrogen-doped carbon-supported scandium single atom precursor solution;

[0102] (5) Preparation of the first sample of nitrogen-doped carbon-supported scandium single-atom material

[0103] The nitrogen-doped carbon-supported scandium single atom precursor solution was allowed to stand at room temperature for 12 hours, the supernatant was removed, the precipitate was retained, and it was washed with deionized water for 3 times to obtain a preliminary product of the nitrogen-doped carbon-supported scandium single atom precursor solution material;

[0104] (6) Pyrolysis

[0105] The initial product of the scandium single-atom precursor solution material supported by nitrogen-doped carbon was placed in a vacuum oven and dried under vacuum at 200 °C for 12 hours to obtain a scandium single-atom material supported by nitrogen-doped high specific surface area carbon.

[0106] The scandium single-atom material supported by nitrogen-doped high specific surface area carbon of Comparative Example 5 was subjected to structural characterization, and its specific surface area was obtained as 1626 m 2 g -1 . Through X-ray photoelectron spectroscopy testing, the successful introduction of nitrogen and scandium elements was confirmed. Among them, the doping content of scandium element was 0.35 at%, and the doping content of nitrogen element was 1.02 at%. The scandium single-atom supported by nitrogen-doped high specific surface area carbon of Comparative Example 5 only reached 3.28 wt% in the hydrogen adsorption and desorption at liquid nitrogen temperature (77 K) through performance testing. From this result, it shows that the specific surface area of the scandium single-atom supported by nitrogen-doped high specific surface area carbon of Comparative Example 5 has decreased, thus affecting its hydrogen storage performance.

[0107] I. Structure and properties of transition metal single-atom solid hydrogen storage materials supported by three-dimensional porous carbon

[0108] In the material structure characterization, through Figure 5 and Figure 6 comparison, it can be found that Figure 5 the diffraction peaks of the high specific surface area carbon obtained by calcination are relatively smooth, and no other impurities are generated. Figure 6 In

[0109] In the hydrogen storage performance test, it can be seen that Figure 7 the hydrogen adsorption and desorption amount of the high specific surface area carbon obtained by calcination in Figure 8 reached 4.4 wt%, and the hydrogen adsorption and desorption curves basically coincided. Figure 9 In Figure 9It can be seen that when the high specific surface area carbon obtained by calcination absorbs hydrogen for 5.9 hours, the pressure reaches 50.1 Pa, and dehydrogenation takes 4.3 hours. And in Figure 10 It shows that for the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon, when it absorbs hydrogen for 5 hours, the pressure reaches 50 Pa, and dehydrogenation only takes 3 hours, which is faster than that of high specific surface area carbon in terms of the hydrogen absorption and desorption rate.

[0110] II. Effects achieved by transition metal single-atom solid hydrogen storage materials supported by two- and three-dimensional porous carbon

[0111] Through BET, XRD, SEM and other experimental tests on the experimental results of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon in Example 1, the high specific surface area carbon obtained by calcination in Comparative Example 1, and the control group, it can be known that compared with the high specific surface area carbon obtained by calcination, the hydrogen storage performance of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon is more excellent. The main reason is that scandium, as a rare earth single atom, has multi-shell electrons and rich electron orbits that are beneficial to strongly adsorb H2 molecules, and can form strong coordination bonds with the modified carbon carrier; on this basis, doping semi-metallic antimony can provide more active sites for hydrogen storage, reduce the reaction energy barrier for adsorbing and desorbing hydrogen, and thus improve the hydrogen storage efficiency of the scandium single-atom solid hydrogen storage material supported by semi-metallic antimony-doped high specific surface area carbon.

Claims

1. A method for preparing a semi-metallic antimony-doped high specific surface area carbon-supported scandium single atom solid hydrogen storage material, characterized in that: the specific steps are: S1 Preparation of Antimony-doped High Specific Surface Area Carbon Materials Sb2O4 and porous carbon were fully mixed in a mass ratio of 1.5:8, heated to 900°C for calcination for 3 hours under the protection of a nitrogen atmosphere, and then cooled to room temperature under the protection of a nitrogen atmosphere to obtain an antimony-doped high specific surface area carbon material; S2 Preparation of antimony-doped high specific surface area carbon material dispersion The antimony-doped high specific surface area carbon material and deionized water are mixed at a mass ratio of 1:200, and stirred sufficiently to obtain an antimony-doped high specific surface area carbon material dispersion; S3. Preparation of scandium chloride solution ScCl3·6H2O and deionized water are uniformly mixed in a mass ratio of 1:30 to 1:35 and stirred thoroughly to obtain a scandium chloride solution; S4 is used to prepare a semi-metallic antimony-doped carbon-supported scandium single atom precursor solution According to the mass ratio of porous carbon in the antimony-doped high specific surface area carbon material to ScCl3·6H2O in the scandium chloride solution of 10:1, the antimony-doped high specific surface area carbon material dispersion is added with the scandium chloride solution while stirring, and then deionized water is added at a volume ratio of 3:2 to the antimony-doped high specific surface area carbon material dispersion to obtain a semi-metallic antimony-doped carbon-supported scandium single atom precursor solution; S5. Preparation of the first sample of semi-metallic antimony-doped carbon-supported scandium single-atom material The semi-metallic antimony-doped carbon-supported scandium single atom precursor solution is allowed to stand at room temperature, the supernatant is removed, the precipitate is retained, and it is washed with deionized water for ≥3 times to obtain a preliminary product of the semi-metallic antimony-doped carbon-supported scandium single atom material; S6, high temperature pyrolysis The initial product of semi-metallic antimony-doped carbon-supported scandium single-atom material is vacuum-dried at 200° C. to obtain a semi-metallic antimony-doped high specific surface area carbon-supported scandium single-atom solid-state hydrogen storage material.

2. The method for preparing the semi-metallic antimony doped high specific surface area carbon supported scandium single atom solid hydrogen storage material according to claim 1, characterized in that: The vacuum drying time is 12 to 15 hours.

3. The method for preparing the semi-metallic antimony doped high specific surface area carbon supported scandium single atom solid hydrogen storage material according to claim 1, characterized in that: In step S3, the mass ratio of ScCl3·6H2O to deionized water is 1:31.

25.

4. The method for preparing the semi-metallic antimony doped high specific surface area carbon supported scandium single atom solid hydrogen storage material according to claim 1, characterized in that: When step S1 heats ScCl3·6H2O and deionized water, the heating rate is 10°C / min.

5. The method for preparing the semi-metallic antimony doped high specific surface area carbon supported scandium single atom solid hydrogen storage material according to claim 1, characterized in that: The stirring speed of step S4 is 50 rpm, and the stirring time is 8 hours.

6. The method for preparing the semi-metallic antimony doped high specific surface area carbon supported scandium single atom solid hydrogen storage material according to claim 1, characterized in that: The specific surface area of ​​the porous carbon is 2000-2100m 2 g -1 .

7. The method for preparing the semi-metallic antimony doped high specific surface area carbon supported scandium single atom solid hydrogen storage material according to claim 1, characterized in that: The standing time is 10 to 12 hours.

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