Magnesium-based composite hydrogen storage material, preparation method therefor and use thereof

Abstract

The present disclosure relates to the technical field of hydrogen storage materials, and specifically provides a magnesium-based composite hydrogen storage material, a preparation method therefor and a use thereof. The magnesium-based composite hydrogen storage material provided by the present disclosure comprises a hydrogenated combustion product of a carbonized bimetallic metal-organic framework material and MgH2, wherein the carbonized bimetallic metal-organic framework material comprises a carbon support, and nickel and zinc oxide doped into the carbon support. The magnesium-based composite hydrogen storage material exhibits excellent hydrogen absorption and desorption kinetic cycling stability, and can significantly reduce the apparent activation energy for hydrogen desorption in magnesium-based materials.

Description

Magnesium-based composite hydrogen storage material, preparation method and application thereof TECHNICAL FIELD

[0001] The present disclosure relates to the field of solid-state hydrogen storage, in particular, to a magnesium-based composite hydrogen storage material, a preparation method and application thereof. BACKGROUND

[0002] With the depletion of fossil fuels, hydrogen is considered as a rich and effective energy carrier, and hydrogen energy is considered as the most promising green energy. However, there are some drawbacks that hinder its utilization and development, such as efficient and safe storage and transportation of hydrogen. Magnesium-based hydrogen storage material (MgH2) has attracted extensive attention due to its high hydrogen density (7.6wt%), excellent reversibility, natural abundance and low cost. However, due to the unsatisfactory thermodynamic stability and slow kinetics, the development of MgH2 has encountered a bottleneck. Due to the stable Mg-H bond, the dehydrogenation enthalpy and entropy of MgH2 is high, up to 75kJ·mol -1 H2and 135kJ·mol -1 H2, it cannot completely release hydrogen when the temperature is lower than 623K. The dehydrogenation activation energy (Ea) of MgH2 is as high as 156kJ·mol -1 H2, which is the basic kinetic barrier.

[0003] In order to solve this problem, i.e. to improve the hydrogen storage technology of Mg / MgH2, the current research mainly has the following three methods: alloying, nanocrystallization and catalyst doping.

[0004] CN118308634A discloses a magnesium-based composite hydrogen storage material and a preparation method thereof. The magnesium-based composite hydrogen storage material is prepared by introducing alloying element Ni and catalyst niobium oxide, combining mechanical alloying, first hydrogenation reaction and second hydrogenation reaction. This method optimizes the phase composition, microstructure and micro defects of the magnesium-rich composite hydrogen storage material to some extent, accelerates the hydrogenation process of the material system, shortens the hydrogenation period, improves the hydrogenation effect, and also improves the hydrogen absorption and desorption thermodynamic properties of the system.

[0005] Therefore, how to improve the thermodynamic and kinetic performance of MgH2 has become a problem to be solved in the field.

[0006] DISCLOSURE

[0007] The purpose of the present disclosure includes providing a magnesium-based composite hydrogen storage material, a preparation method and application thereof. The magnesium-based composite hydrogen storage material exhibits excellent hydrogen absorption and desorption kinetic cycle stability, and can greatly reduce the apparent activation energy of hydrogen desorption of magnesium-based materials.

[0008] In order to achieve at least one of the above purposes of the present disclosure, the following technical solutions are adopted:

[0009] In a first aspect, the present disclosure provides a magnesium-based composite hydrogen storage material, comprising a hydrogenated combustion product of a carbonized bimetallic metal organic framework material and MgH2.

[0010] Preferably, the carbonized bimetallic metal organic framework material comprises a carbon carrier, and nickel and zinc oxide doped in the carbon carrier.

[0011] Preferably, the mass ratio of the hydrogenated combustion product of the carbonized bimetallic metal organic framework material and MgH2 is (0.5-2):(5-15).

[0012] Preferably, the carbonized bimetallic metal organic framework material is obtained by carbonizing and calcining a bimetallic metal organic framework material.

[0013] Preferably, the raw materials for preparing the bimetallic metal organic framework material comprise the following components by weight fraction:

[0014] 0.5-1.0 parts of a nickel source, 0.5-1.0 parts of a zinc source, 0.1-1.0 parts of an organic ligand, 1-5 parts of a surfactant, and 30-60 parts of a solvent.

[0015] Preferably, the nickel source comprises a nickel salt.

[0016] Preferably, the nickel salt comprises any one or a combination of at least two of nickel nitrate, nickel chloride, nickel sulfate, nickel acetate, nickel phosphate, nickel carbonate, or nickel oxalate.

[0017] Preferably, the zinc source comprises a zinc salt.

[0018] Preferably, the zinc salt comprises any one or a combination of at least two of zinc nitrate, zinc chloride, zinc sulfate, zinc acetate, zinc phosphate, zinc carbonate, or zinc oxalate.

[0019] Preferably, the organic ligand comprises a benzoic acid compound.

[0020] Preferably, the benzoic acid compound comprises any one or a combination of at least two of terephthalic acid, isophthalic acid, phthalic acid, trimesic acid, pyromellitic acid, or mellitic acid.

[0021] Preferably, the surfactant comprises any one or a combination of at least two of polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polyethyleneimine, or polyoxyethylene ether.

[0022] Preferably, the solvent comprises any one or a combination of at least two of methanol, ethanol, methyl butanone, methyl isobutyl ketone, N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, or 1,4-dioxane.

[0023] In a second aspect, the present disclosure provides a preparation method of the magnesium-based composite hydrogen storage material according to the first aspect, the preparation method comprising the following steps:

[0024] The carbonized bimetallic metal organic framework material and the metal Mg are mixed, and after hydrogenation combustion and ball milling, the magnesium-based composite hydrogen storage material is obtained.

[0025] Preferably, in the process of hydrogenation combustion, the pressure of hydrogen is 3.5-4.0 MPa, the heating rate is 2-5 K / min, the holding temperature is 623-673 K, and the holding time is 30-40 h.

[0026] Preferably, in the process of ball milling, the rotation speed of ball milling is 300-500 rpm, the ball milling time is 10-20 min, the interval is 5-10 min, and the ball-to-material ratio is (20-40):1.

[0027] Preferably, the carbonized bimetallic metal organic framework material is prepared by the following steps:

[0028] (1) mixing a nickel source, a zinc source, an organic ligand, and a surfactant, and stirring to obtain a raw material solution;

[0029] (2) performing a solvothermal reaction on the raw material solution to obtain a bimetallic metal organic framework material;

[0030] (3) carbonizing the bimetallic metal organic framework material to obtain the carbonized bimetallic metal organic framework material.

[0031] Preferably, in step (1), the stirring temperature is 293-323 K.

[0032] Preferably, in step (1), the stirring time is 0.5-2 h.

[0033] Preferably, in step (2), the solvothermal reaction temperature is 323-523 K.

[0034] Preferably, in step (2), the solvothermal reaction time is 5-20 h.

[0035] Preferably, in step (2), the solvothermal reaction further comprises the following post-treatment step:

[0036] The solid product in the product solution obtained by the solvothermal reaction is collected, and the solid product is sequentially subjected to washing, drying, and grinding to obtain the bimetallic metal organic framework material.

[0037] Preferably, the reagent used for washing is ethanol.

[0038] Preferably, the temperature of the drying is 233-433 K.

[0039] Preferably, the particle size of the ground bimetallic metal organic framework material is 500-1000 μm.

[0040] Preferably, in step (3), the heating rate of the carbonization is 2-10 K / min.

[0041] Preferably, in step (3), the holding temperature of the carbonization is 773-973 K.

[0042] Preferably, in step (3), the holding time of the carbonization is 2-10 h.

[0043] In a third aspect, the present disclosure provides a magnesium-based composite hydrogen storage material as described in the first aspect for use as a hydrogen storage material.

[0044] Compared with the prior art, the present disclosure has the following beneficial effects:

[0045] (1) The present disclosure provides a magnesium-based composite hydrogen storage material, which comprises a hydrogenation combustion product of a carbonized bimetallic metal organic framework material and MgH2; wherein the carbonized bimetallic metal organic framework material comprises a carbon carrier and nickel and zinc oxide doped in the carbon carrier. The magnesium-based composite hydrogen storage material exhibits excellent hydrogen absorption and desorption kinetic cycle stability, and can greatly reduce the apparent activation energy of hydrogen desorption of the magnesium-based material.

[0046] (2) The present disclosure provides a preparation method of the magnesium-based composite hydrogen storage material. The preparation method is simple, and the raw materials are easy to obtain. After the magnesium is compounded with the carbonized bimetallic metal organic framework material by the method of the present disclosure, based on the good dispersion characteristics of the carbon material and the stable MgNiZn phase existing in the whole hydrogen absorption and desorption process, the magnesium-based composite hydrogen storage material exhibits excellent hydrogen absorption and desorption kinetic cycle stability, and greatly reduces the apparent activation energy of hydrogen desorption of the magnesium-based material. BRIEF DESCRIPTION OF DRAWINGS

[0047] Fig. 1 is a DSC curve diagram of the magnesium-based composite hydrogen storage material provided in Example 1.

[0048] Fig. 2 is a corresponding fitting curve diagram of the DSC curve diagram of the magnesium-based composite hydrogen storage material provided in Example 1.

[0049] Fig. 3 is a DSC curve diagram of the MgH2 hydrogen storage material provided in Comparative Example 1.

[0050] Fig. 4 is a corresponding fitting curve diagram of the DSC curve diagram of the MgH2 hydrogen storage material provided in Comparative Example 1.

[0051] Figure 5 is a graph of the kinetic curves of the magnesium-based composite hydrogen storage material provided in Example 1 after 10 cycles at 623 K. DETAILED DESCRIPTION

[0052] The embodiments of the present disclosure will be described in detail below with examples, but those skilled in the art will understand that the following examples are only for illustration of the present disclosure and should not be regarded as limiting the scope of the present disclosure. If specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used.

[0053] In a first aspect, the present disclosure provides a magnesium-based composite hydrogen storage material, which comprises a hydrogenation combustion product of a carbonized bimetallic metal organic framework material and MgH2.

[0054] The carbonized bimetallic metal organic framework material comprises a carbon carrier and nickel and zinc oxide doped in the carbon carrier.

[0055] In the present disclosure, after the magnesium is compounded with the carbonized bimetallic metal organic framework material (hereinafter referred to as Ni / C / ZnO), the magnesium-based composite hydrogen storage material obtained by hydrogenation combustion contains the hydrogenation combustion product of Ni / C / ZnO and MgH2. Based on the good dispersion characteristics of the bimetallic metal organic framework material and the MgNiZn phase stably existing in the whole hydrogen absorption and desorption process, the magnesium-based composite hydrogen storage material exhibits excellent hydrogen absorption and desorption kinetic cycle stability, and also greatly reduces the apparent activation energy of hydrogen desorption of the magnesium-based material.

[0056] In an optional embodiment of the present disclosure, the mass ratio of the hydrogenation combustion product of the carbonized bimetallic metal organic framework material and MgH2 is (0.5-2):(5-15).

[0057] For example, "0.5-2" can be 0.5, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, etc.

[0058] For example, "5-15" can be 5, 6, 8, 10, 12, 14, 15, etc.

[0059] In an optional embodiment of the present disclosure, the carbonized bimetallic metal organic framework material is obtained by carbonization calcination of a bimetallic metal organic framework material.

[0060] In an optional embodiment of the present disclosure, the raw materials for preparing the bimetallic metal organic framework material comprise the following components by weight fraction:

[0061] The nickel source is 0.5-1.0 parts, the zinc source is 0.5-1.0 parts, the organic ligand is 0.1-1.0 parts, the surfactant is 1-5 parts, and the solvent is 30-60 parts.

[0062] In an optional embodiment of the present disclosure, the content of the nickel source in the raw material for preparing the double-metal metal organic framework material is 0.5-1.0 parts, for example, it can be 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, etc.

[0063] In an optional embodiment of the present disclosure, the content of the zinc source in the raw material for preparing the double-metal metal organic framework material is 0.5-1.0 parts, for example, it can be 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, etc. In an optional embodiment of the present disclosure, the content of the organic ligand in the raw material for preparing the double-metal metal organic framework material is 0.1-1.0 parts, for example, it can be 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, etc.

[0064] In an optional embodiment of the present disclosure, the content of the surfactant in the raw material for preparing the double-metal metal organic framework material is 1-5 parts, for example, it can be 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc.

[0065] In an optional embodiment of the present disclosure, the content of the solvent in the raw material for preparing the double-metal metal organic framework material is 30-60 parts, for example, it can be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, etc.

[0066] In an optional embodiment of the present disclosure, the nickel source comprises a nickel salt.

[0067] In an optional embodiment of the present disclosure, the nickel salt comprises any one or a combination of at least two of nickel nitrate, nickel chloride, nickel sulfate, nickel acetate, nickel phosphate, nickel carbonate or nickel oxalate.

[0068] In a preferred embodiment of the present disclosure, the nickel salt is nickel nitrate.

[0069] In an optional embodiment of the present disclosure, the zinc source comprises a zinc salt.

[0070] In an optional embodiment of the present disclosure, the zinc salt comprises any one or a combination of at least two of zinc nitrate, zinc chloride, zinc sulfate, zinc acetate, zinc phosphate, zinc carbonate or zinc oxalate.

[0071] In a preferred embodiment of the present disclosure, the zinc salt is zinc nitrate.

[0072] In an optional embodiment of the present disclosure, the organic ligand comprises a benzoic acid compound.

[0073] In an alternative embodiment of the present disclosure, the benzoic acid compound comprises any one or a combination of at least two of terephthalic acid, isophthalic acid, phthalic acid, trimesic acid, pyromellitic acid or mellitic acid.

[0074] In a preferred embodiment of the present disclosure, the organic ligand is terephthalic acid.

[0075] In an alternative embodiment of the present disclosure, the surfactant comprises any one or a combination of at least two of polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polyethylene imine or polyoxyethylene ether.

[0076] In a preferred embodiment of the present disclosure, the surfactant is polyvinylpyrrolidone.

[0077] In an alternative embodiment of the present disclosure, the solvent comprises any one or a combination of at least two of methanol, ethanol, methyl butanone, methyl isobutyl ketone, N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile or 1,4-dioxane.

[0078] In a preferred embodiment of the present disclosure, the solvent is a mixture of N,N-dimethylformamide and ethanol.

[0079] In a preferred embodiment of the present disclosure, the volume ratio of N,N-dimethylformamide and ethanol is (1-5):(1-5), for example, it can be 1:1, 2:1, 3:1, 4:1, 5:1, 1:2, 3:2, 5:2, 1:3, 2:3, 4:3, 5:3, 1:4, 3:4, 5:4, 1:5, 2:5, 3:5, 4:5, etc.

[0080] In a second aspect, the present disclosure provides a preparation method of the magnesium-based composite hydrogen storage material according to the first aspect, the preparation method comprising the following steps:

[0081] The carbonized bimetallic metal-organic framework material and the metal Mg are mixed, and after hydrogenation combustion and ball milling, the magnesium-based composite hydrogen storage material is obtained.

[0082] In an alternative embodiment of the present disclosure, in the process of hydrogenation combustion, the pressure of hydrogen is 3.5-4.0 MPa, for example, it can be 3.5 MPa, 3.6 MPa, 3.7 MPa, 3.8 MPa, 3.9 MPa, 4.0 MPa, etc.

[0083] In an alternative embodiment of the present disclosure, in the process of hydrogenation combustion, the heating rate is 2-5 K / min, for example, it can be 2 K / min, 2.5 K / min, 3 K / min, 3.5 K / min, 4 K / min, 4.5 K / min, 5 K / min, etc.

[0084] In an optional embodiment of the present disclosure, the temperature of the holding in the hydrogenation combustion process is 623-673 K, for example, it can be 623 K, 633 K, 643 K, 653 K, 663 K, 673 K, etc.

[0085] In an optional embodiment of the present disclosure, the time of the holding in the hydrogenation combustion process is 30-40 h, for example, it can be 30 h, 32 h, 34 h, 36 h, 38 h, 40 h, etc.

[0086] In an optional embodiment of the present disclosure, the rotation speed of the ball milling in the ball milling process is 300-500 rpm, for example, it can be 300 rpm, 320 rpm, 340 rpm, 360 rpm, 380 rpm, 400 rpm, 420 rpm, 440 rpm, 460 rpm, 480 rpm, 500 rpm, etc.

[0087] In an optional embodiment of the present disclosure, the time of the ball milling in the ball milling process is 10-20 min, for example, it can be 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, etc.

[0088] In an optional embodiment of the present disclosure, the intermittent time between each ball milling in the ball milling process is 5-10 min, for example, it can be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, etc.

[0089] In an optional embodiment of the present disclosure, the ball-to-material ratio in the ball milling process is (20-40):1, for example, it can be 20:1, 22:1, 25:1, 28:1, 30:1, 32:1, 34:1, 35:1, 36:1, 40:1, etc.

[0090] In an optional embodiment of the present disclosure, the carbonized bimetallic metal-organic framework material is prepared by the following steps:

[0091] (1) mixing a nickel source, a zinc source, an organic ligand and a surfactant, and stirring to obtain a raw material solution;

[0092] (2) performing a solvothermal reaction on the raw material solution to obtain a bimetallic metal-organic framework material;

[0093] (3) carbonizing the bimetallic metal-organic framework material to obtain the carbonized bimetallic metal-organic framework material.

[0094] In an alternative embodiment of the present disclosure, in step (1), the stirring temperature is 293-323 K, for example, it can be 293 K, 296 K, 303 K, 306 K, 313 K, 316 K, 323 K, etc.

[0095] In an alternative embodiment of the present disclosure, in step (1), the stirring time is 0.5-2 h, for example, it can be 0.5 h, 0.6 h, 0.8 h, 1 h, 1.2 h, 1.4 h, 1.6 h, 1.8 h, 2 h, etc.

[0096] In an alternative embodiment of the present disclosure, in step (2), the temperature of the solvothermal reaction is 323-523 K, for example, it can be 323 K, 333 K, 343 K, 353 K, 363 K, 373 K, 383 K, 393 K, 403 K, 413 K, 423 K, 433 K, 443 K, 453 K, 463 K, 473 K, 483 K, 493 K, 503 K, 513 K, 523 K, etc.

[0097] In an alternative embodiment of the present disclosure, in step (2), the time of the solvothermal reaction is 5-20 h, for example, it can be 5 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, etc.

[0098] In an alternative embodiment of the present disclosure, in step (2), the solvothermal reaction further comprises the following post-treatment steps:

[0099] The solid product in the product liquid obtained by the solvothermal reaction is collected, and the solid product is sequentially subjected to washing, drying, and grinding to obtain the double-metal metal-organic framework material.

[0100] In an alternative embodiment of the present disclosure, the reagent used for washing the solid product is ethanol.

[0101] In an alternative embodiment of the present disclosure, the temperature for drying the solid product is 233-433 K, for example, it can be 223 K, 233 K, 243 K, 253 K, 263 K, 273 K, 283 K, 293 K, 303 K, 313 K, 323 K, 333 K, 343 K, 353 K, 363 K, 373 K, 383 K, 393 K, 403 K, 413 K, 423 K, 433 K, etc.

[0102] In an alternative embodiment of the present disclosure, the particle size of the ground bimetallic metal organic framework material is 500-1000 μm, for example, it can be 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm, 1000 μm, etc.

[0103] In an alternative embodiment of the present disclosure, in step (3), the heating rate of carbonization is 2-10 K / min, for example, it can be 2 K / min, 3 K / min, 4 K / min, 5 K / min, 6 K / min, 7 K / min, 8 K / min, 9 K / min, 10 K / min, etc.

[0104] In an alternative embodiment of the present disclosure, in step (3), the holding temperature of carbonization is 773-973 K, for example, it can be 773 K, 783 K, 793 K, 803 K, 813 K, 823 K, 833 K, 843 K, 853 K, 863 K, 873 K, 883 K, 893 K, 903 K, 913 K, 923 K, 933 K, 943 K, 953 K, 963 K, 973 K, etc.

[0105] In an alternative embodiment of the present disclosure, in step (3), the holding time of carbonization is 2-10 h, for example, it can be 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h, 8.5 h, 9 h, 9.5 h, 10 h, etc.

[0106] In a third aspect, the present disclosure provides a magnesium-based composite hydrogen storage material as described in the first aspect for use as a hydrogen storage material.

[0107] In order to facilitate a clearer understanding of the content of the present disclosure, specific examples are described in detail as follows. However, these examples are only exemplary and do not constitute any limitation on the scope of the present disclosure.

[0108] Example 1

[0109] The present example provides a magnesium-based composite hydrogen storage material, which is prepared by the following steps:

[0110] S1, Preparation of carbonized bimetallic metal organic framework material (Ni / C / ZnO):

[0111] 50 mL of a mixed solution of DMF and ethanol (V DMF :V ET=1:1), 0.25 g of Ni(NO3)2·6H2O, 0.25 g of Zn(NO3)2·6H2O, 0.15 g of terephthalic acid, 1.0 g of polyvinylpyrrolidone (molecular weight 44,000-54,000) were sequentially added to the mixed solution, and stirring was performed at 298 K using a magnetic stirrer for 0.5 h to obtain a raw material solution; then, the raw material solution was filled into a 100 mL reaction kettle, transferred to a blast drying oven reaction, and reacted at a temperature of 423 K for 10 h. After the reaction was completed, the solid product was collected, washed by centrifugation with anhydrous ethanol for 3 times, and then the product was dried in a blast drying oven at 333 K. Finally, the dried sample was ground to a fineness of 800 μm, loaded into a cleaned porcelain boat, transferred to a tube furnace under the protection of argon atmosphere, and the temperature was increased to a target temperature of 873 K at a temperature increasing rate of 2 K / min, and the temperature was kept at the target temperature for 5 h. After the tube furnace was naturally cooled to room temperature, the product was collected to obtain Ni / C / ZnO.

[0112] S2, Preparation of a magnesium-based composite hydrogen storage material:

[0113] The metal Mg powder and the Ni / C / ZnO mixture were weighed according to a mass ratio of 9:1, and the magnesium-based composite hydrogen storage material was obtained after hydrogenation combustion and high-energy ball milling;

[0114] In the hydrogenation combustion process, the pressure of hydrogen was 4.0 MPa, the temperature increasing rate was 2 K / min, the temperature for heat preservation was 673 K, and the heat preservation time was 40 h;

[0115] In the high-energy ball milling process, the rotation speed of ball milling was 500 rpm, the ball milling time was 15 min, the intermittent time was 5 min, and the ball-to-material ratio was 30:1.

[0116] Example 2

[0117] The example provides a magnesium-based composite hydrogen storage material, which is prepared by the following steps:

[0118] S1, Preparation of a carbonized bimetallic metal organic framework material (Ni / C / ZnO):

[0119] A mixed solution of 50 mL of DMF and ethanol (V DMF :V ET=1:2), 0.3g of Ni(NO3)2·6H2O, 0.3g of Zn(NO3)2·6H2O, 0.1g of terephthalic acid, 0.5g of polyvinylpyrrolidone (molecular weight 44000-54000) were sequentially added into the mixed solution, and the mixture was stirred at 293K for 1h by a magnetic stirrer to obtain a raw material solution; then the raw material solution was filled into a 100mL reactor, and the reactor was transferred to a blast drying oven for reaction at a temperature of 423K for 5h. After the reaction was completed, the solid product was collected, washed by centrifugation with anhydrous ethanol for 3 times, and then the product was dried in a blast drying oven at 333K. Finally, the dried sample was ground to a size of 500μm, and then was filled into a cleaned porcelain boat, which was transferred to a tube furnace under the protection of argon atmosphere. The temperature was increased to a target temperature of 773K at a rate of 5K / min, and the temperature was kept at the target temperature for 5h. After the tube furnace was naturally cooled to room temperature, the product was collected to obtain Ni / C / ZnO.

[0120] S2, preparation of a magnesium-based composite hydrogen storage material:

[0121] The magnesium-based composite hydrogen storage material was obtained by mixing the metal Mg powder and the Ni / C / ZnO in a mass ratio of 9:1, and then by hydrogenation combustion and high-energy ball milling.

[0122] In the hydrogenation combustion process, the pressure of hydrogen was 3.5MPa, the heating rate was 3K / min, the holding temperature was 648K, and the holding time was 30h.

[0123] In the high-energy ball milling process, the rotation speed of the ball mill was 300rpm, the ball milling time was 10min, the intermittent time was 8min, and the ball-to-material ratio was 20:1.

[0124] Example 3

[0125] The example provides a magnesium-based composite hydrogen storage material, which is prepared by the following steps:

[0126] S1, preparation of a carbonized bimetallic metal organic framework material (Ni / C / ZnO):

[0127] A mixed solution of 50mL of DMF and ethanol (V DMF :V ET= 1:5), 0.4 g of Ni(NO3)2.6H2O, 0.4 g of Zn(NO3)2.6H2O, 0.2 g of terephthalic acid, 1.5 g of polyvinylpyrrolidone (molecular weight 44000-54000) were added into the mixed solution in turn, stirring was carried out at 303 K for 2 h by a magnetic stirrer, to obtain a raw material solution; then the raw material solution was filled into a 100 mL reaction kettle, transferred to a blast drying oven reaction, reacted at a temperature of 423 K for 1.5 h, after the reaction was completed, the solid product was collected, washed by centrifugation with anhydrous ethanol for 3 times, then the product was dried by a blast drying oven at 333 K, finally the dried sample was ground to 1000 μm and loaded into a cleaned porcelain boat, transferred to a tube furnace protected by argon atmosphere, the temperature was increased to the target temperature 973 K at a temperature increasing rate of 8 K / min, and kept at the temperature for 5 h, after the tube furnace was naturally cooled to room temperature, the product was collected, to obtain Ni / C / ZnO.

[0128] S2, preparation of a magnesium-based composite hydrogen storage material:

[0129] Metal Mg powder and the Ni / C / ZnO mixture were weighed according to a mass ratio of 9:1, and the magnesium-based composite hydrogen storage material was obtained after hydrogenation combustion and high-energy ball milling;

[0130] In the hydrogenation combustion process, the pressure of hydrogen was 3.8 MPa, the temperature increasing rate was 5 K / min, the temperature for holding was 623 K, and the holding time was 35 h;

[0131] In the high-energy ball milling process, the rotation speed of ball milling was 400 rpm, the ball milling time was 20 min, the interval was 10 min, and the ball-to-material ratio was 40:1.

[0132] Example 4

[0133] The embodiment provides a magnesium-based composite hydrogen storage material, which is different from the magnesium-based composite hydrogen storage material in example 1 only in that zinc nitrate in S1 is replaced by zinc chloride with the same mass; and nickel nitrate is replaced by nickel acetate with the same mass, and other steps are completely consistent with those in example 1.

[0134] Example 5

[0135] The embodiment provides a magnesium-based composite hydrogen storage material, which is different from the magnesium-based composite hydrogen storage material in example 1 only in that zinc nitrate in S1 is replaced by zinc chloride with the same mass; and nickel nitrate is replaced by nickel acetate with the same mass, and other steps are completely consistent with those in example 1.

[0136] Example 6

[0137] The embodiment provides a magnesium-based composite hydrogen storage material, which is different from the magnesium-based composite hydrogen storage material in example 1 only in that DMF is not added into the solvent in S1, and other steps are completely consistent with those in example 1.

[0138] Example 7

[0139] This example provides a magnesium-based composite hydrogen storage material, which is only different from example 1 in that no ethanol is added in the solvent of S1, and other steps are completely consistent with example 1.

[0140] Example 8

[0141] This example provides a magnesium-based composite hydrogen storage material, which is only different from example 1 in that the ligand terephthalic acid of S1 is replaced by equal mass of isophthalic acid, and other steps are completely consistent with example 1.

[0142] Example 9

[0143] This example provides a magnesium-based composite hydrogen storage material, which is only different from example 1 in that the ligand terephthalic acid of S1 is replaced by equal mass of trimesic acid, and other steps are completely consistent with example 1.

[0144] Example 10

[0145] This example provides a magnesium-based composite hydrogen storage material, which is only different from example 1 in that the surfactant polyvinylpyrrolidone of S1 is replaced by equal mass of polyethylene glycol, and other steps are completely consistent with example 1.

[0146] Example 11

[0147] This example provides a magnesium-based composite hydrogen storage material, which is only different from example 1 in that the surfactant polyvinylpyrrolidone of S1 is replaced by equal mass of polyvinyl alcohol, and other steps are completely consistent with example 1.

[0148] Example 12

[0149] This example provides a magnesium-based composite hydrogen storage material, which is only different from example 1 in that the metal Mg powder and the Ni / C / ZnO mixture in S2 are weighed according to a mass ratio of 15:1, and other steps are completely consistent with example 1.

[0150] Example 13

[0151] This example provides a magnesium-based composite hydrogen storage material, which is only different from example 1 in that the metal Mg powder and the Ni / C / ZnO mixture in S2 are weighed according to a mass ratio of 1:1, and other steps are completely consistent with example 1.

[0152] Example 14

[0153] The embodiment provides a magnesium-based composite hydrogen storage material, which is different from the embodiment 1 only in that in S2, the pressure of hydrogen is 3.0 MPa, the temperature rising rate is 6 K / min, the temperature for heat preservation is 683 K, the time for heat preservation is 25 h, and other steps are completely consistent with the embodiment 1.

[0154] Example 15

[0155] The embodiment provides a magnesium-based composite hydrogen storage material, which is different from the embodiment 1 only in that in S2, the pressure of hydrogen is 3.0 MPa, the temperature rising rate is 6 K / min, the temperature for heat preservation is 683 K, the time for heat preservation is 25 h, and other steps are completely consistent with the embodiment 1.

[0156] Comparative example 1

[0157] The comparative example provides a MgH2 hydrogen storage material, which is prepared by the following steps: after hydrogenation combustion and high-energy ball milling of metal Mg powder, the MgH2 hydrogen storage material is obtained.

[0158] In the hydrogenation combustion process, the pressure of hydrogen is 4.0 MPa, the temperature rising rate is 2 K / min, the temperature for heat preservation is 673 K, and the time for heat preservation is 40 h; in the ball milling process, the rotating speed of ball milling is 500 rpm, the time for ball milling is 15 min, the interval is 5 min, and the ball-to-material ratio is 30:1.

[0159] Comparative example 2

[0160] The comparative example provides a magnesium-based composite hydrogen storage material, which is prepared by the following steps:

[0161] S1, preparation of carbonized bimetallic metal organic framework material (Ni / C):

[0162] 50 mL of a mixed solution (V DMF :V ET=1:1), 0.25 g of Ni(NO3)2·6H2O, 0.15 g of terephthalic acid, 1.0 g of polyvinylpyrrolidone (molecular weight 44,000-54,000) were sequentially added to the mixed solution, and stirring was performed at 298 K using a magnetic stirrer for 0.5 h to obtain a raw material solution; then, 100 mL of a reaction vessel was filled with the raw material solution, and the reaction was performed in a blast drying oven at a temperature of 423 K for 10 h. After the reaction was completed, the solid product was collected, washed by centrifugation with anhydrous ethanol three times, and then the product was dried in a blast drying oven at 333 K. Finally, the dried sample was ground to a fineness of 800 μm, and then loaded into a cleaned porcelain boat, transferred to a tube furnace under an argon atmosphere, and heated to a target temperature of 873 K at a temperature increase rate of 2 K / min, and maintained at the temperature for 5 h. After the tube furnace was naturally cooled to room temperature, the product was collected to obtain Ni / C.

[0163] S2, Preparation of a magnesium-based composite hydrogen storage material:

[0164] Metal Mg powder and the Ni / C were weighed in a mass ratio of 9:1, mixed, and subjected to hydrogenation combustion and high-energy ball milling to obtain the magnesium-based composite hydrogen storage material;

[0165] In the hydrogenation combustion process, the pressure of hydrogen was 4.0 MPa, the temperature increase rate was 2 K / min, the temperature for heat preservation was 673 K, and the heat preservation time was 40 h. In the high-energy ball milling process, the rotation speed of ball milling was 500 rpm, the ball milling time was 15 min, the interval was 5 min, and the ball-to-material ratio was 30:1.

[0166] Comparative Example 3

[0167] This comparative example provides a magnesium-based composite hydrogen storage material prepared by the following steps:

[0168] S1, Preparation of a carbonized bimetallic metal organic framework material (C / ZnO):

[0169] A mixed solution of 50 mL of DMF and ethanol (V DMF :V ET= 1:1), 0.25 g of Zn(NO3)2.6H2O, 0.15 g of terephthalic acid, 1.0 g of polyvinylpyrrolidone (molecular weight 44,000-54,000) were sequentially added to the mixed solution, and stirring was performed at 298 K using a magnetic stirrer for 0.5 h to obtain a raw material solution. Then, 100 mL of a reaction vessel was filled with the raw material solution, and the reaction was performed in a blast drying oven at a temperature of 423 K for 10 h. After the reaction was completed, the solid product was collected, washed by centrifugation with anhydrous ethanol three times, and then the product was dried in a blast drying oven at 333 K. Finally, the dried sample was ground to a fineness of 800 μm, and then loaded into a cleaned porcelain boat, and transferred to a tube furnace under an argon atmosphere. The temperature was increased to a target temperature of 873 K at a temperature increase rate of 2 K / min, and the temperature was maintained at the target temperature for 5 h. After the tube furnace was naturally cooled to room temperature, the product was collected to obtain C / ZnO.

[0170] S2, Preparation of a magnesium-based composite hydrogen storage material:

[0171] Metal Mg powder and the C / ZnO were mixed in a mass ratio of 9:1, and the magnesium-based composite hydrogen storage material was obtained after hydrogenation combustion and high-energy ball milling.

[0172] In the hydrogenation combustion process, the pressure of hydrogen was 4.0 MPa, the temperature increase rate was 2 K / min, the temperature for heat preservation was 673 K, and the heat preservation time was 40 h. In the high-energy ball milling process, the rotation speed of ball milling was 500 rpm, the ball milling time was 15 min, the interval was 5 min, and the ball-to-material ratio was 30:1.

[0173] Comparative Example 4

[0174] This comparative example provides a magnesium-based composite hydrogen storage material, which is prepared by the following steps: metal Mg powder, metal Ni powder, and zinc oxide powder are mixed in a mass ratio of 9:0.5:0.5, and then MgH2 hydrogen storage material is obtained after hydrogenation combustion and high-energy ball milling.

[0175] In the hydrogenation combustion process, the pressure of hydrogen was 4.0 MPa, the temperature increase rate was 2 K / min, the temperature for heat preservation was 673 K, and the heat preservation time was 40 h. In the high-energy ball milling process, the rotation speed of ball milling was 500 rpm, the ball milling time was 15 min, the interval was 5 min, and the ball-to-material ratio was 30:1.

[0176] Comparative Example 5

[0177] This comparative example provides a magnesium-based composite hydrogen storage material, which is prepared by the following steps:

[0178] S1, Preparation of a bimetallic metal organic framework material (Ni / ZnO-MOF)

[0179] A 50 mL mixed solution of DMF and ethanol (V DMF :V ET = 1:1) was prepared, and 0.25 g of Ni(NO3)2·6H2O, 0.25 g of Zn(NO3)2·6H2O, 0.15 g of terephthalic acid, and 1.0 g of polyvinylpyrrolidone (molecular weight 44,000-54,000) were sequentially added to the mixed solution. The mixture was stirred at 298 K using a magnetic stirrer for 0.5 h to obtain a raw material solution. The raw material solution was then transferred to a 100 mL reaction kettle and reacted in a blast drying oven at a temperature of 423 K for 10 h. After the reaction was completed, the solid product was collected and washed by centrifugation with anhydrous ethanol three times. The product was then dried in a blast drying oven at 333 K. Finally, the dried sample was ground to a size of 800 μm, and the product was collected to obtain the Ni / ZnO-MOF.

[0180] S2, Preparation of a magnesium-based composite hydrogen storage material

[0181] Metal Mg powder and the Ni / ZnO-MOF were mixed in a mass ratio of 9:1, and the magnesium-based composite hydrogen storage material was obtained after hydrogenation combustion and high-energy ball milling.

[0182] In the hydrogenation combustion process, the pressure of hydrogen was 4.0 MPa, the heating rate was 2 K / min, the holding temperature was 673 K, and the holding time was 40 h. In the high-energy ball milling process, the rotation speed was 500 rpm, the ball milling time was 15 min, the interval was 5 min, and the ball-to-material ratio was 30:1.

[0183] Test Example 1

[0184] DSC Test

[0185] Test Sample: The magnesium-based composite hydrogen storage material provided in Examples 1-15 and the hydrogen storage material provided in Comparative Examples 1-5.

[0186] Test Method: The sample saturated with hydrogen was tested at different heating rates using a thermogravimetric analyzer to obtain the peak hydrogen release temperature at different heating rates.

[0187] The test results are shown in Table 1 and Figs. 1-4.

[0188] Table 1

[0189] As shown in Table 1, the DSC test results of the magnesium-based composite hydrogen storage material of the present disclosure show that, at different heating rates, the peak temperature is reduced to below 652.1 K at a heating rate of 5 K / min, the peak temperature is reduced to below 673.9 K at a heating rate of 10 K / min, the peak temperature is reduced to below 695.1 K at a heating rate of 15 K / min, and the peak temperature is reduced to below 701.1 K at a heating rate of 20 K / min. It is illustrated that the dehydrogenation peak temperature of the magnesium-based composite hydrogen storage material of the present disclosure is significantly reduced, and the thermodynamic performance is obviously improved.

[0190] In addition, FIG. 1 is a DSC curve diagram of the magnesium-based composite hydrogen storage material provided in Example 1. FIG. 2 is a corresponding fitting curve diagram of the DSC curve diagram of the magnesium-based composite hydrogen storage material provided in Example 1. FIG. 3 is a DSC curve diagram of the MgH2 hydrogen storage material provided in Comparative Example 1. FIG. 4 is a corresponding fitting curve diagram of the DSC curve diagram of the MgH2 hydrogen storage material provided in Comparative Example 1. From the comparison between Example 1 and Comparative Example 1, it can be more intuitively seen that the dehydrogenation temperature of the magnesium-based composite hydrogen storage material provided in the present disclosure is significantly reduced compared with the pure MgH2 hydrogen storage material, the apparent activation energy of the magnesium-based material for dehydrogenation is greatly reduced, and the thermodynamic performance is obviously improved.

[0191] Test Example 2

[0192] Hydrogen absorption and desorption kinetics cycle stability test

[0193] Test sample: magnesium-based composite hydrogen storage materials provided in Examples 1-15, and hydrogen storage materials provided in Comparative Examples 1-5.

[0194] Test method: The sample was subjected to hydrogen absorption and desorption cycle stability test at a fixed temperature of 623 K and a fixed hydrogen pressure of 3.0 MPa, and the hydrogen absorption and desorption time was 20 min.

[0195] The test results are shown in Table 2 and FIG. 5 as follows:

[0196] Table 2

[0197] As shown in Table 2, the magnesium-based composite hydrogen storage material and the preparation method thereof of the present disclosure have stable hydrogen storage cycle kinetics performance, and the hydrogen storage capacity can still be maintained at more than 96.15% after 10 times of hydrogen absorption and desorption cycles, which illustrates that the magnesium-based composite hydrogen storage material of the present disclosure, after being compounded with Mg and Ni / C / ZnO, based on the good dispersion characteristics of the carbon material and the MgNiZn phase stably existing in the whole hydrogen absorption and desorption process, exhibits excellent hydrogen absorption and desorption kinetics cycle stability. Industrial applicability

[0198] The magnesium-based composite hydrogen storage material and the preparation method thereof are not limited by the types and components of raw materials, the raw materials are low in cost, simple and easy to obtain, and the process flow is simple, and the method is suitable for large-scale industrialization, and the prepared magnesium-based composite hydrogen storage material exhibits excellent hydrogen absorption and desorption kinetic cycle stability. Meanwhile, the apparent activation energy of the magnesium-based material is greatly reduced.

Claims

1. A magnesium-based composite hydrogen storage material, characterized in that, The magnesium-based composite hydrogen storage material comprises a hydrogenation combustion product of carbonized bimetallic metal organic framework material and MgH2. The carbonized bimetallic metal organic framework material comprises a carbon carrier and nickel and zinc oxide doped in the carbon carrier.

2. The magnesium-based composite hydrogen storage material of claim 1, wherein, The mass ratio of the hydrogenation combustion product of the carbonized bimetallic metal organic framework material and MgH2 is (0.5-2):(5-15).

3. The magnesium-based composite hydrogen storage material of claim 1, wherein, The carbonized bimetallic metal organic framework material is obtained by carbonization calcination of a bimetallic metal organic framework material. The raw materials for preparing the bimetallic metal organic framework material comprise the following components by weight fraction: 0.5-1.0 parts of a nickel source, 0.5-1.0 parts of a zinc source, 0.1-1.0 parts of an organic ligand, 1-5 parts of a surfactant, and 30-60 parts of a solvent.

4. The magnesium-based composite hydrogen storage material of claim 3, wherein, The nickel source comprises a nickel salt; The nickel salt comprises any one or a combination of at least two of nickel nitrate, nickel chloride, nickel sulfate, nickel acetate, nickel phosphate, nickel carbonate, or nickel oxalate.

5. The magnesium-based composite hydrogen storage material of claim 3, wherein the magnesium-based composite hydrogen storage material is characterized by: The zinc source comprises a zinc salt; The zinc salt comprises any one or a combination of at least two of zinc nitrate, zinc chloride, zinc sulfate, zinc acetate, zinc phosphate, zinc carbonate, or zinc oxalate.

6. The magnesium-based composite hydrogen storage material of claim 3, wherein, The organic ligand comprises a benzoic acid compound; The benzoic acid compound comprises any one or a combination of at least two of terephthalic acid, isophthalic acid, phthalic acid, trimesic acid, pyromellitic acid, or mellitic acid.

7. The magnesium-based composite hydrogen storage material of claim 3, wherein the magnesium-based composite hydrogen storage material is characterized by: The surfactant comprises any one or a combination of at least two of polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polyethyleneimine, or polyoxyethylene ether.

8. The magnesium-based composite hydrogen storage material of claim 3, wherein, The solvent comprises any one or a combination of at least two of methanol, ethanol, methyl butanone, methyl isobutyl ketone, N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, or 1,4-dioxane.

9. A method for producing the magnesium-based composite hydrogen storage material according to any one of claims 1 to 8, characterized by, The preparation method comprises the following steps: The magnesium-based composite hydrogen storage material is obtained by mixing the carbonized bimetallic metal organic framework material and metal Mg, hydrogenation combustion, and ball milling.

10. The method for preparing the magnesium-based composite hydrogen storage material according to claim 9, characterized in that, In the hydrogenation combustion process, the hydrogen pressure is 3.5-4.0 MPa, the heating rate is 2-5 K / min, the holding temperature is 623-673 K, and the holding time is 30-40 h.

11. The method for preparing the magnesium-based composite hydrogen storage material according to claim 9, characterized in that, In the ball milling process, the rotation speed is 300-500 rpm, the ball milling time is 10-20 min, the interval is 5-10 min, and the ball-to-material ratio is (20-40):

1.

12. The method for preparing the magnesium-based composite hydrogen storage material according to claim 9, characterized in that, The carbonized bimetallic metal organic framework material is prepared by the following steps: (1) mixing a nickel source, a zinc source, an organic ligand, and a surfactant, and stirring to obtain a raw material solution; (2) performing a solvothermal reaction on the raw material solution to obtain a bimetallic metal organic framework material; (3) carbonizing the bimetallic metal organic framework material to obtain the carbonized bimetallic metal organic framework material.

13. The method for preparing the magnesium-based composite hydrogen storage material according to claim 12, characterized in that, In step (1), the stirring temperature is 293-323 K; And / or, in step (1), the stirring time is 0.5-2 h.

14. The method for preparing the magnesium-based composite hydrogen storage material according to claim 12, characterized in that, In step (2), the solvothermal reaction temperature is 323-523 K; And / or, in step (2), the solvothermal reaction time is 5-20 h.

15. The method for preparing the magnesium-based composite hydrogen storage material according to claim 12, characterized in that, In step (2), the solvothermal reaction is followed by the following post-processing steps: The solid product in the product solution obtained by the solvothermal reaction is collected, and the solid product is sequentially subjected to washing, drying and grinding to obtain the double-metal metal organic framework material.

16. The method of claim 15, wherein the magnesium-based composite hydrogen storage material is prepared by the steps of: a) mixing a magnesium compound with a carbon material; b) heating the mixture to a temperature of 600- 1000°C; and c) cooling the mixture to room temperature. The reagent used in the washing is ethanol; and / or, the temperature for the drying is 233-433 K; and / or, the particle size of the double-metal metal organic framework material after the grinding is 500-1000 μm.

17. The method for preparing the magnesium-based composite hydrogen storage material according to claim 12, characterized in that, In step (3), the heating rate for the carbonization is 2-10 K / min; and / or, in step (3), the holding temperature for the carbonization is 773-973 K; and / or, in step (3), the holding time for the carbonization is 2-10 h.

18. Use of the magnesium-based composite hydrogen storage material according to any one of claims 1-8 as a hydrogen storage material.

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