Preparation method and application of Ni-based MOF material subjected to mild thermal activation treatment

Abstract

The invention discloses a preparation method and application of a Ni-based MOF material subjected to mild thermal activation treatment, and belongs to the technical field of metal organic framework materials. The preparation method of the Ni-based MOF material comprises the following steps: mixing an organic ligand and a regulator in a solvent to obtain a ligand mixed solution; the method comprises the following steps: mixing a nickel source in dimethylformamide to obtain a metal salt solution; mixing the ligand mixed solution with a metal salt solution to obtain a precursor solution, and carrying out heating reaction to obtain a Ni-based MOF material precursor; and carrying out primary thermal activation treatment on the Ni-based MOF material precursor, and then carrying out secondary thermal activation treatment to obtain the Ni-based MOF material. According to the preparation method disclosed by the invention, a solvent in MOF pore channels is removed by utilizing low-temperature thermal calcination, more controllable high-activity unsaturated Ni sites of SBUs are exposed, adsorption and activation of methanol and water molecules are promoted, and the aim of a reaction system environment without a sacrificial agent is achieved, so that the photo-thermal hydrogen production performance of the whole reaction system is improved.

Description

Technical Field

[0001] The invention relates to the technical field of metal organic framework materials, and in particular to a preparation method and application of a Ni-based MOF material subjected to mild thermal activation treatment. Background Art

[0002] Under the current strategic background of global energy sustainable development, energy security and environmental pollution have become key issues that human society needs to solve urgently. In view of this, developing green energy and exploring sustainable alternatives to fossil fuels are the primary tasks of modern energy technology development. As an energy option with sustainable development characteristics and clean and environmentally friendly properties, hydrogen stands out among many energy carriers and shows extremely broad application prospects. However, the safety of hydrogen storage and transportation has become a major bottleneck restricting its further industrial application and academic research. To solve this problem, methanol (CH3OH), as a safe, economical and efficient liquid organic hydrogen storage material, is regarded as an ideal solution to the problem of hydrogen storage and transportation due to its high hydrogen storage capacity. Although the traditional mode of thermal catalytic methanol liquid phase reforming hydrogen production (APRM) has met certain industrial and market needs, this technology generally requires high temperatures of 190°C to 300°C to achieve efficient hydrogen generation in the thermal catalytic process, and requires an alkaline environment, high energy consumption and high cost, and still needs further modification.

[0003] Metal-organic frameworks (MOFs) are a new type of porous material, which is self-assembled by organic ligands and metal ions or clusters through coordination bonds. They have unique intramolecular pore structure, high specific surface area, adjustable porosity, open crystal morphology and multifunctionality. These characteristics make MOF materials show great application potential in the field of catalysis and become a hot material in current catalytic scientific research. In view of this, exploring the application of MOF materials in the fields of hydrogen storage, methanol synthesis and conversion is of great significance to promoting the sustainable development of hydrogen energy technology. Summary of the invention

[0004] The primary purpose of the present invention is to address the problem of high energy consumption in the current thermal catalytic methanol liquid phase reforming hydrogen production, and propose a way of photothermal coupling synergistic effect to reduce energy consumption in the reaction process, and use the energy provided by sunlight to provide a driving force for the reaction; by further improving the performance efficiency of methanol liquid phase reforming hydrogen production under the synergistic effect of photothermal coupling, so that the catalytic activity can be maintained under the premise of a lower reaction temperature; at the same time, in response to the problem of the need to add alkali as a sacrificial agent, it is proposed to expose more metal sites and increase the absorption of the substrate to achieve energy, so as to react in an alkali-free environment, thereby achieving stable, low energy consumption, no sacrificial agent, and high-efficiency hydrogen production, and then provide a Ni-based MOF material catalyst with mild thermal activation treatment for application in photothermal catalytic methanol liquid phase alkali-free reforming hydrogen production.

[0005] By designing the structure of Ni-based MOF precursor, metal and carbon-based components can be evenly dispersed in the periodic metal framework of Ni-based MOF, effectively avoiding the aggregation and growth of metal nanoparticles. At the same time, the Ni-based MOF precursor is calcined at low temperature to remove the residual solvent in the Ni-based MOF pores, fully expose the unsaturated active metal Ni sites on SBUs (secondary building units), obtain abundant surface active sites while maintaining the crystal structure, and promote the adsorption and activation of substrates methanol and water.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a method for preparing a Ni-based MOF material by mild thermal activation treatment, comprising the following steps:

[0008] The organic ligand and the regulator are mixed in a solvent to obtain a ligand mixed solution; the nickel source is mixed in dimethylformamide to obtain a metal salt solution;

[0009] The ligand mixed solution and the metal salt solution are mixed to obtain a precursor solution, and the mixture is heated for reaction to obtain a Ni-based MOF material precursor;

[0010] The Ni-based MOF material precursor is subjected to a first thermal activation treatment, and then subjected to a second thermal activation treatment to obtain the Ni-based MOF material.

[0011] Preferably, the step of mixing in the solvent is carried out under stirring conditions, and the stirring speed is 300-500 rpm and the time is 30 min.

[0012] Preferably, the step of mixing in dimethylformamide is carried out under stirring conditions, the stirring speed is 300-500 rpm, and the time is 30 minutes.

[0013] Preferably, the step of mixing the ligand mixed solution and the metal salt solution is carried out under stirring conditions, and the stirring speed is 300-500 rpm and the time is 30 minutes.

[0014] Preferably, the organic ligand is 2,5-dihydroxyterephthalic acid; the regulator is salicylic acid;

[0015] The organic ligand concentration in the ligand mixed solution is 0.1-0.5 mol / L, and the regulator concentration is 0.01-0.3 mol / L.

[0016] Preferably, the solvent is a mixed solution of ethanol and water, and the volume ratio of the ethanol, water and dimethylformamide is 1:1:1.

[0017] Preferably, the nickel source is nickel nitrate hexahydrate; and the nickel source concentration in the metal salt solution is 0.3-1.0 mol / L.

[0018] Preferably, the heating reaction is carried out at a temperature of 150° C. and for 24 h.

[0019] Preferably, after the heating reaction, the method further comprises the following steps: centrifuging the reaction solution, and rinsing the obtained solid phase component with N,N-dimethylformamide and methanol to obtain a Ni-based MOF material precursor.

[0020] Preferably, the heating rate of the first thermal activation treatment is 5°C / min, the atmosphere is a protective atmosphere, the temperature is 60°C, and the time is 3 hours. Maintaining this temperature for 3 hours is to remove the residual solvent in the MOF pores.

[0021] Preferably, the secondary thermal activation treatment is performed at a heating rate of 5°C / min, in a protective atmosphere, at a temperature of 350°C, and for 3 h.

[0022] The second technical solution of the present invention is to provide a Ni-based MOF material obtained according to the above preparation method.

[0023] The third technical solution of the present invention is to provide an application of the above-mentioned Ni-based MOF material in the field of hydrogen production by photothermal catalytic liquid-phase reforming of methanol.

[0024] The high-porosity Ni-based MOF material catalyst subjected to low-temperature thermal calcination treatment in the present invention has relatively excellent catalytic activity in the photothermal catalytic liquid-phase reforming of methanol to produce hydrogen, and is suitable for use in the field of photothermal catalytic liquid-phase reforming of methanol to produce hydrogen.

[0025] Technical solution 4 of the present invention: Provided is a method for producing hydrogen by photothermal catalytic liquid phase reforming of methanol, comprising the following steps:

[0026] The above-mentioned Ni-based MOF material, methanol and water are mixed and reacted under anaerobic, light and heating conditions to produce hydrogen.

[0027] Preferably, the heating temperature is 160-210° C.; and the molar ratio of methanol to water is 1:1-5.

[0028] The technical principles of the present invention are as follows:

[0029] The present invention discloses a method for preparing a Ni-based MOF material catalyst subjected to mild thermal activation treatment and its application in photothermal catalytic methanol liquid phase alkali-free reforming hydrogen production. Based on the fact that divalent Ni ions are easy to combine with the carboxyl and hydroxyl groups of the organic ligand 2,5-dihydroxyterephthalic acid to form an ideally coordinated MOF-74, and doped with an organic ligand salicylic acid similar to the organic ligand 2,5-dihydroxyterephthalic acid, salicylic acid replaces a portion of the 2,5-dihydroxyterephthalic acid during the hydrothermal process to form MOF-74-DE (60) with coordination environment defects, and the Ni-based MOF precursor is mildly calcined to remove the residual solvent in the Ni-based MOF pores, fully expose the unsaturated active metal Ni sites on the SBUs, obtain abundant surface active sites while maintaining the crystal structure, and promote the adsorption and activation of the substrates methanol and water. Through mild calcination treatment, the Ni-based MOF photothermal catalyst can maintain the crystal morphology while obtaining abundant surface active sites, which is beneficial to the adsorption and activation of methanol and water molecules. Therefore, the catalyst prepared by the present invention is suitable for the alkali-free decomposition of methanol and water to produce hydrogen under the synergistic effect of light and heat.

[0030] The present invention discloses a Ni-based MOF material treated with mild thermal activation, which uses a mild thermal activation strategy to adjust the electronic structure and obtain abundant surface active sites while maintaining the crystal morphology. After thermal activation, a Ni-MOF material loaded with unsaturated Ni active sites in different proportions can be obtained. As the activation temperature increases, the Ni-based MOF material exposes more active metal sites, thereby improving the catalytic activity of the catalyst. The controllable high-activity unsaturated Ni sites promote the adsorption and activation of methanol and water molecules, and while maintaining its MOF morphology, the Ni-based MOF material treated with mild thermal activation can be used for alkaline-free methanol liquid phase hydrogen production.

[0031] The beneficial technical effects of the present invention are as follows:

[0032] The hydrogen production performance of MOF-74-DE (350) can reach 91705.89 μmol·g in a non-alkaline methanol-water environment at 210℃. Cat -1 ·h -1 , it can reach 433.59 μmol·g in a non-alkaline methanol-water environment at 160℃ Cat-1 ·h -1 The present invention achieves excellent hydrogen production performance without sacrificial agents and at a relatively low temperature (210°C), and explores the temperature limit (160°C) of hydrogen production performance without sacrificial agents.

[0033] The Ni-based MOF material catalyst prepared by the present invention undergoes mild thermal activation treatment, and utilizes low-temperature thermal calcination to remove the solvent in the MOF pores, exposing more SBUs controllable high-activity unsaturated Ni sites, promoting the adsorption and activation of methanol and water molecules, and achieving the purpose of a reaction system environment without sacrificial agents, thereby improving the photothermal hydrogen production performance of the entire reaction system.

[0034] The preparation method of the present invention has simple process, is easy to operate, is green, environmentally friendly, pollution-free, and low-cost, and has broad application prospects in photothermal catalytic methanol liquid phase reforming to produce hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 XRD spectra of the products of Examples 1-2 and MOF-74-DE (60) in Example 1.

[0037] Figure 2 The scanning electron microscope images of MOF-74-DE (60) and MOF-74-DE (350) in Example 1 are shown in Figure 1. Figure a) is MOF-74-DE (60) and figure b) is MOF-74-DE (350).

[0038] Figure 3 This is the transmission electron microscope image of MOF-74-DE (350) in Example 1.

[0039] Figure 4 This is a comparison chart of hydrogen production from methanol liquid phase reforming of MOF-74-DE (350) in Example 1 under photothermal catalysis and alkali-free environment.

[0040] Figure 5 This is a performance comparison chart of methanol liquid phase reforming to produce hydrogen in a photothermal catalytic alkali-free environment using the methods of Effect Examples 1 and 7-13. DETAILED DESCRIPTION

[0041] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0042] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0043] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0044] The words “include,” “including,” “have,” “contain,” etc. used in the present invention are open-ended terms, meaning including but not limited to.

[0045] All raw materials used in the following examples and comparative examples of the present invention are commercially available products.

[0046] Example 1

[0047] A Ni-based MOF catalyst treated with mild thermal activation, composed of Ni 2+ The nanoparticles are formed by coordination reaction with organic ligands 2,5-dihydroxyterephthalic acid and salicylic acid, wherein the hydroxyl groups and carboxyl groups of the organic ligands 2,5-dihydroxyterephthalic acid and salicylic acid are connected with Ni (II) nanoparticles.

[0048] The specific preparation steps of Ni-based MOF material catalyst are as follows:

[0049] S1. Adding organic ligands 2,5-dihydroxyterephthalic acid and salicylic acid to ethanol and deionized water to obtain a ligand mixed solution; adding nickel source nickel nitrate hexahydrate to dimethylformamide to obtain a metal salt solution; mixing the obtained ligand mixed solution and the metal salt solution, and fully dispersing them to obtain a precursor solution of Ni-based MOF material; wherein the molar ratio of 2,5-dihydroxyterephthalic acid and salicylic acid (ligand and regulator) to the nickel source is 1:5.0, and the volume ratio of dimethylformamide, ethanol and water is 1:1:1;

[0050] S2. The precursor solution of the Ni-based MOF material obtained in step S1 is subjected to a hydrothermal reaction at 150° C. for 24 h. After the reaction is completed, the precursor solution is centrifuged to obtain a Ni-based MOF material precursor;

[0051] S3. The above-mentioned Ni-based MOF material precursor was placed in a reduction tube, and the temperature was raised to 60°C at a heating rate of 5°C / min in a N2 environment for 3 hours of activation to obtain MOF-74-DE (60) with coordination environment defects.

[0052] S4. The MOF-74-DE (60) obtained in S3 was placed in a reduction tube and heated to 350°C at a rate of 5°C / min in a N2 environment for 3 hours of activation to obtain a Ni-based MOF material catalyst, which was recorded as MOF-74-DE (350).

[0053] Example 2

[0054] The only difference from Example 1 is that the activation temperature in S4 is changed from 350°C to 100°C, 150°C, 200°C, 250°C, 300°C, and 400°C, respectively, and the prepared Ni-based MOF material catalysts are respectively recorded as MOF-74-DE (100), MOF-74-DE (150), MOF-74-DE (200), MOF-74-DE (250), MOF-74-DE (300), and MOF-74-DE (400).

[0055] Effect Example 1

[0056] The MOF-74-DE (350) in Example 1 was subjected to a non-alkaline test on the photo-thermal catalytic performance of methanol reforming hydrogen production reaction.

[0057] The non-alkaline test of the photo-thermal catalytic performance of methanol reforming hydrogen production reaction was carried out in a stainless steel high-pressure photo-thermal autoclave (CEL-HPR50, 50 mL) with a quartz lining, a magnetic stirrer and a visual sapphire window. The specific test method is as follows:

[0058] The MOF-74-DE (350) in Example 1 was transferred to the inner lining of a reactor containing 10 mL of a MeOH / H2O mixed solution (nMeOH / nH2O=1:3); the sealed reactor was repeatedly filled and discharged with 2 MPa N2 three times, and then reacted at a set temperature (210°C) for 80 min in a 2 MPa N2 atmosphere, irradiated with a 300 W Xe lamp (CEL-HXF300-T3) and stirred at 500 rpm. After the reaction, the gas products in the headspace of the autoclave were analyzed by GC chromatography to determine the amount of H2 produced.

[0059] Effect Example 2

[0060] The only difference from Effect Example 1 is that the set temperature is changed to 200°C.

[0061] Effect Example 3

[0062] The only difference from Effect Example 1 is that the set temperature is changed to 190°C.

[0063] Effect Example 4

[0064] The only difference from Effect Example 1 is that the set temperature is changed to 180°C.

[0065] Effect Example 5

[0066] The only difference from Effect Example 1 is that the set temperature is changed to 170°C.

[0067] Effect Example 6

[0068] The only difference from Effect Example 1 is that the set temperature is changed to 160°C.

[0069] Effect Example 7

[0070] The only difference from Effect Example 1 is that MOF-74-DE (350) is replaced with an equal mass of MOF-74-DE (60).

[0071] Effect Example 8

[0072] The only difference from Effect Example 1 is that MOF-74-DE (350) is changed to an equal mass of MOF-74-DE (100).

[0073] Effect Example 9

[0074] The only difference from Effect Example 1 is that MOF-74-DE (350) is changed to an equal mass of MOF-74-DE (150).

[0075] Effect Example 10

[0076] The only difference from Effect Example 1 is that MOF-74-DE (350) is changed to an equal mass of MOF-74-DE (200).

[0077] Effect Example 11

[0078] The only difference from Effect Example 1 is that MOF-74-DE (350) is changed to an equal mass of MOF-74-DE (250).

[0079] Effect Example 12

[0080] The only difference from Effect Example 1 is that MOF-74-DE (350) is replaced with an equal mass of MOF-74-DE (300).

[0081] Effect Example 13

[0082] The only difference from Effect Example 1 is that MOF-74-DE (350) is changed to an equal mass of MOF-74-DE (400).

[0083] The performance test data of effect examples 1-13 are shown in Table 1 and Figure 1-5 shown.

[0084] Table 1 Catalytic performance test data

[0085]

[0086] As can be seen from Table 1, the Ni-MOF material prepared by the method for preparing the Ni-based MOF material with mild thermal activation treatment provided by the present invention, when used for methanol reforming reaction in a non-alkaline photothermal catalytic environment, MOF-74-DE (350) can make the reforming of methanol to produce hydrogen have a hydrogen conversion rate of 91705.89 μmol·g at 210°C. Cat -1 ·h -1 The hydrogen production rate is also improved; it also makes the methanol reforming reaction in the low temperature non-alkaline photothermal catalytic environment have good performance, and at 160℃, the methanol reforming hydrogen production reaction can have a hydrogen production rate of 433.59 μmol·g Cat -1 ·h -1 The hydrogen production rate of MOF-74-DE (60) after heat treatment at different temperatures was 5030.81 μmol·g at 210 °C. Cat -1 ·h -1 The hydrogen production rate of MOF-74-DE (400) is 50231.76 μmol·g at 210 °C. Cat -1 ·h -1 The Ni-based MOF material prepared by the present invention after mild thermal activation has excellent catalytic activity. Thanks to the coordination environment defects, the unsaturated active metal Ni sites on the SBUs are fully exposed. After low-temperature calcination in a N2 environment and removal of the residual solvent in the Ni-based MOF pores, the Ni-MOF material exposes more active metal sites. The highly active unsaturated Ni sites promote the adsorption and activation of methanol and water molecules, and can produce hydrogen in the absence of a sacrificial agent while having a MOF framework.

[0087] Figure 1 XRD spectra of the products of Examples 1-2 and MOF-74-DE (60) in Example 1.

[0088] Figure 1 In the figure, a represents the XRD pattern of MOF-74-DE (60), b represents the XRD pattern of MOF-74-DE (100), c represents the XRD pattern of MOF-74-DE (150), d represents the XRD pattern of MOF-74-DE (200), e represents the XRD pattern of MOF-74-DE (250), f represents the XRD pattern of MOF-74-DE (300), g represents the XRD pattern of MOF-74-DE (350), and h represents the XRD pattern of MOF-74-DE (400).

[0089] from Figure 1 It can be seen that the materials obtained by heat activation treatment of MOF-74-DE at different temperatures have good crystallinity, and the characteristic peaks of MOF after calcination all appear, indicating that the porous framework of MOF-74-DE materials did not collapse during the regulated mild heat treatment.

[0090] Figure 2 The scanning electron microscope images of MOF-74-DE (60) and MOF-74-DE (350) in Example 1 are shown in Figure 1. Figure a) is MOF-74-DE (60) and figure b) is MOF-74-DE (350).

[0091] Depend on Figure 2 It can be seen that the structure of MOF-74-DE (350) did not collapse due to the increase in temperature, which shows the skeleton of MOF-74-DE and proves that the catalyst has been successfully prepared.

[0092] Figure 3 This is the transmission electron microscope image of MOF-74-DE (350) in Example 1.

[0093] from Figure 3 The lattice fringes of the products Ni(111) and Ni(200) can be measured, and Figure 1 The diffraction peaks of the XRD pattern are consistent with those of the control group, indicating that MOF-74-DE (350) has been successfully prepared.

[0094] Figure 4 This is a comparison chart of hydrogen production from methanol liquid phase reforming of MOF-74-DE (350) in Example 1 under photothermal catalysis and alkali-free environment.

[0095] Depend on Figure 4The hydrogen production performance of MOF-74-DE (350) in the photothermal conditions in an alkali-free environment shows that after adjusting the reaction environment from an ideal coordination environment to an unsaturated coordination environment, the hydrogen production performance is also excellent, proving that it is feasible to apply the product of the present invention to an alkali-free methanol-water environment for photothermal phase reforming hydrogen production. A mild thermal activation treatment strategy is adopted to remove the residual solvent in the Ni-based MOF pores and expose more metal sites in MOF-74-DE. Thanks to the full exposure of the unsaturated active metal Ni sites on the SBUs while maintaining the MOF framework, the adsorption and activation of methanol and water molecules can be promoted under the irradiation of sunlight in an environment without sacrificial agents, effectively reducing the activation energy of the substrate methanol-water; it also enables hydrogen production performance at mild temperatures.

[0096] Figure 5 This is a performance comparison chart of methanol liquid phase reforming to produce hydrogen in a photothermal catalytic alkali-free environment using the methods of Effect Examples 1 and 7-13.

[0097] Depend on Figure 5 The hydrogen production performance of MOF-74-DE in the photothermal conditions in an alkali-free environment shows that the hydrogen production performance is improved to a certain extent with the increase of the temperature of the secondary thermal activation, proving that it is feasible to use the product of the present invention in an alkali-free methanol-water environment for photothermal phase reforming hydrogen production. The strategy of mild thermal activation treatment, which benefits from the removal of residual solvent in the Ni-based MOF pores and fully exposes the unsaturated active metal Ni sites on the SBUs, can promote the adsorption and activation of methanol and water molecules in an environment without sacrificial agents, and effectively reduce the activation energy of the substrate methanol-water.

[0098] The above experimental results show that the preparation method of the present invention is green, environmentally friendly, pollution-free and low-cost. The calcination is regulated by mild thermal activation treatment, so that the prepared material not only has the structure of MOF, but also exposes more active metal sites. The synergistic effect of highly active unsaturated Ni sites and high porosity promotes the adsorption and activation of methanol and water molecules, so that the product can produce hydrogen by photothermal catalytic liquid-phase reforming of methanol in a non-alkaline environment.

[0099] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing a Ni-based MOF material by mild thermal activation treatment, characterized in that: The following steps are involved: The organic ligand and the regulator are mixed in a solvent to obtain a ligand mixed solution; the nickel source is mixed in dimethylformamide to obtain a metal salt solution; The ligand mixed solution and the metal salt solution are mixed to obtain a precursor solution, and the mixture is heated for reaction to obtain a Ni-based MOF material precursor; The Ni-based MOF material precursor is subjected to a first thermal activation treatment, and then subjected to a second thermal activation treatment to obtain the Ni-based MOF material.

2. The preparation method according to claim 1, characterized in that: The organic ligand is 2,5-dihydroxyterephthalic acid; the regulator is salicylic acid; The organic ligand concentration in the ligand mixed solution is 0.1-0.5 mol / L, and the regulator concentration is 0.01-0.3 mol / L.

3. The preparation method according to claim 1, characterized in that: The solvent is a mixed solution of ethanol and water, and the volume ratio of the ethanol, water and dimethylformamide is 1:1:

1.

4. The preparation method according to claim 1, characterized in that: The nickel source is nickel nitrate hexahydrate; the nickel source concentration in the metal salt solution is 0.3-1.0 mol / L.

5. The preparation method according to claim 1, characterized in that: The heating reaction was carried out at a temperature of 150° C. and for 24 h.

6. The preparation method according to claim 1, characterized in that: The heating rate of the first thermal activation treatment is 5°C / min, the atmosphere is a protective atmosphere, the temperature is 60°C, and the time is 3 h.

7. The preparation method according to claim 1, characterized in that: The secondary thermal activation treatment was performed at a heating rate of 5°C / min, a protective atmosphere, a temperature of 350°C, and a time of 3 h.

8. A Ni-based MOF material obtained according to the preparation method according to any one of claims 1 to 7.

9. An application of the Ni-based MOF material according to claim 8 in the field of hydrogen production by photothermal catalytic liquid phase reforming of methanol.

10. A method for producing hydrogen by photothermal catalytic methanol liquid phase reforming, characterized in that: The following steps are involved: The Ni-based MOF material according to claim 8, methanol and water are mixed and reacted under anaerobic, light and heating conditions to obtain hydrogen.

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