A supported metal organic framework catalyst, and a preparation method and application thereof

Abstract

The application discloses a supported metal organic framework catalyst and a preparation method and application thereof. The preparation method comprises the following steps: providing a metal salt solution or a complex metal salt solution; uniformly mixing the aqueous metal salt solution or the complex metal salt solution with a synthetic metal organic framework organic solvent mother liquor, and performing a hydrothermal reaction to obtain an intermediate product containing a metal organic framework; and performing preheating treatment on the intermediate product, so that generated metal clusters or metal nanoparticles are uniformly distributed on the surface and pore structure of the metal organic framework to obtain the supported metal organic framework catalyst. The preparation method of the supported metal organic framework catalyst provided by the application has certain limiting effect on the size of the metal nanoparticles by using the pore cage structure of the metal organic framework, different particle size metal nanoparticles can be prepared, and the metal nodes in the structure of the metal organic framework can provide corresponding catalytic activity.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a supported metal-organic framework catalyst, its preparation method, and its application. Background Technology

[0002] my country's energy resources have long been characterized by abundant coal, scarce natural gas, and limited oil, with oil being primarily imported. Therefore, vigorously developing hydrogen energy, which is widely available, has high energy density, and is environmentally friendly, holds significant strategic importance. However, the high cost and safety concerns surrounding hydrogen production, storage, and transportation have consistently limited its development. The "coal-methanol-hydrogen" hydrogen production route offers a promising solution.

[0003] Methanol has a small molecular weight, high hydrogen content, and is relatively stable at room temperature, making it an important hydrogen carrier. my country has a wide range of methanol sources, and as a crucial part of the methanol economy, methanol steam reforming is a convenient and efficient on-site hydrogen production method, avoiding the problem of long-distance hydrogen transportation.

[0004] The core technology of methanol reforming for hydrogen production is the catalyst. Currently reported and applied catalysts mainly include Cu-based catalysts, noble metal catalysts, and photocatalysts. Cu-based catalysts are widely used in methanol reforming for hydrogen production due to their low cost and high activity. Among them, CuZnAlO2 prepared by co-precipitation or precipitation-deposition methods is particularly valuable. x The catalyst has been commercialized. Traditionally prepared Cu-based catalysts supported on alumina are susceptible to various factors, have a small specific surface area, and are prone to agglomeration and sintering during preparation. Therefore, improving the low-temperature activity of Cu-based catalysts is a challenging issue.

[0005] In view of this, in order to solve the technical problems existing in the existing catalysts, the present invention provides a method for preparing and applying a low-temperature supported metal-organic framework catalyst material. Summary of the Invention

[0006] The main objective of this invention is to provide a supported metal-organic framework catalyst, its preparation method, and its application, so as to overcome the shortcomings of the prior art.

[0007] To achieve the aforementioned objectives, the technical solutions adopted in the embodiments of the present invention include:

[0008] This invention provides a method for preparing a supported metal-organic framework catalyst, comprising:

[0009] Provide metal salt solutions or complexed metal salt solutions;

[0010] The metal salt solution or complexed metal salt solution is mixed evenly with the mother liquor of the organic solvent for synthesizing the metal-organic framework, and a hydrothermal reaction is carried out to obtain an intermediate product containing a metal-organic framework.

[0011] The intermediate product is preheated to make the generated metal clusters or metal nanoparticles uniformly distributed on the surface and in the pore structure of the metal-organic framework. The pore cage structure in the metal-organic framework has a certain limiting effect on the size of the nanoparticles, thus obtaining a supported metal-organic framework catalyst.

[0012] Furthermore, the preparation method of the supported metal-organic framework catalyst includes:

[0013] The metal salt precursor with a molar ratio of at least 1:5 to 20 is uniformly mixed with water, or an organic solution or aqueous solution containing organic ligands is uniformly mixed to form a metal salt solution or a complexed metal salt solution.

[0014] Furthermore, the organic solution containing the organic ligand includes both the organic ligand and the organic solvent;

[0015] Furthermore, the metal salt precursor includes a metal-containing nitrate and / or chloride, wherein the metal includes any one or a combination of two or more of Fe, Co, Ni, Zn, Cu, and Al.

[0016] Furthermore, the mother liquor for synthesizing the metal-organic framework organic solvent includes a metal salt precursor, an organic ligand, and an organic solvent.

[0017] Furthermore, the organic ligand includes any one or a combination of two or more of pyromellitic acid, terephthalic acid, or pyridine carboxylic acid ligands.

[0018] Furthermore, the organic solvent includes any one or a combination of two or more of ethanol, methanol, acetonitrile, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0019] Furthermore, the preparation method of the supported metal-organic framework catalyst specifically includes: adding the metal salt solution or complexed metal salt solution to the mother liquor of the synthetic metal-organic framework organic solvent, and carrying out the hydrothermal reaction at 30-180°C for 5-96 hours in a closed environment, and then washing and drying the obtained powder solid particles.

[0020] Furthermore, the preheating treatment includes calcination in a selected gas atmosphere, preferably air or nitrogen.

[0021] This invention also provides a supported metal-organic framework catalyst prepared by the aforementioned method, comprising a metal-organic framework material and metal clusters or metal nanoparticles, wherein the metal clusters or metal nanoparticles are uniformly distributed on the surface and within the pore structure of the metal-organic framework material.

[0022] Furthermore, the content of metal nanoparticles in the supported metal-organic framework catalyst is 0.01–5 wt%.

[0023] Furthermore, the porosity of the metal-organic framework is 5% to 50%, and the pore size of the contained channels is 0.1 to 1.5 nm.

[0024] Furthermore, the size of the metal nanoparticles is 0.3–5 nm.

[0025] This invention also provides the application of the aforementioned supported metal-organic framework catalyst in the catalytic methanol steam reforming reaction.

[0026] This invention also provides a method for methanol steam reforming reaction, comprising:

[0027] Provides a gas stream containing methanol and water vapor;

[0028] The gas stream is brought into contact with the aforementioned supported metal-organic framework catalyst at 100–300°C to achieve methanol steam reforming for hydrogen production.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The preparation method of the supported metal-organic framework catalyst of the present invention uses a metal-organic framework whose porous cage structure has a certain limiting effect on the size of metal nanoparticles, and can prepare metal nanoparticles of different sizes. Furthermore, the metal nodes in the metal-organic framework can provide corresponding catalytic activity and work together with metal nanoparticles to apply to the methanol steam reforming reaction.

[0031] (2) The preparation method of the supported metal-organic framework catalyst for catalytic methanol steam reforming provided by the present invention is simple. The prepared supported metal-organic framework catalyst has the advantages of low cost, non-toxicity, high activity and long life. It can be used for on-board methanol reforming to produce hydrogen and has a wide application prospect. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1a and Figure 1b This is a TEM image of the supported metal-organic framework catalyst in a typical embodiment 1 of the present invention.

[0034] Figure 2 This is the XRD pattern of the supported metal-organic framework catalyst in a typical embodiment 1 of the present invention.

[0035] Figure 3 This is a graph showing the hydrogen yield evaluation of a typical embodiment of the present invention and a commercial catalyst CuO / ZnO / Al2O3 in the methanol reforming hydrogen production reaction. Detailed Implementation

[0036] One aspect of this invention provides a method for preparing a supported metal-organic framework catalyst, comprising:

[0037] Provide metal salt solutions or complexed metal salt solutions;

[0038] The metal salt solution or complexed metal salt solution is mixed evenly with the mother liquor of the organic solvent for synthesizing the metal-organic framework, and a hydrothermal reaction is carried out to obtain an intermediate product containing a metal-organic framework.

[0039] The intermediate product is preheated to ensure that the generated metal clusters or metal nanoparticles are uniformly distributed on the surface and within the pore structure of the metal-organic framework, thereby obtaining a supported metal-organic framework catalyst.

[0040] In this embodiment of the invention, the metal-organic framework has a certain limiting effect on the particle size of metal nanoparticles, and the metal nodes can provide corresponding catalytic activity, working together with metal nanoparticles in the methanol steam reforming reaction.

[0041] In some preferred embodiments, the method for preparing the supported metal-organic framework catalyst includes:

[0042] The metal salt precursor with a molar ratio of at least 1:5 to 20 is uniformly mixed with water, or an organic solution or aqueous solution containing organic ligands is uniformly mixed to form a metal salt solution or a complexed metal salt solution.

[0043] In some more preferred embodiments, the organic solution containing the organic ligand comprises both the organic ligand and the organic solvent.

[0044] In some more preferred embodiments, the molar ratio of the metal salt precursor to the organic ligand is 1 to 20:1.

[0045] In some more preferred embodiments, the molar ratio of the organic solvent to the metal salt precursor is 1 to 1500:1, preferably 800 to 1000:1.

[0046] In some more preferred embodiments, the metal salt precursor includes a metal-containing nitrate and / or chloride, wherein the metal may include any one or more combinations of Fe, Co, Ni, Zn, Cu, Al, etc., but is not limited thereto; preferably, the metal may be any one or more combinations of Fe, Zn, Cu, Al.

[0047] In some preferred embodiments, the mother liquor for synthesizing the metal-organic framework organic solvent includes a metal salt precursor, an organic ligand, and an organic solvent.

[0048] In some more preferred embodiments, the metal salt precursor includes a metal-containing nitrate and / or chloride, wherein the metal may include any one or more combinations of Fe, Co, Ni, Zn, Cu, Al, etc., but is not limited thereto; preferably, the metal may be any one or more combinations of Fe, Zn, Cu, Al.

[0049] In some more preferred embodiments, the mother liquor for synthesizing the metal-organic framework organic solvent may also include one or more of nitric acid, phosphoric acid, hydrochloric acid, acetic acid, etc., but is not limited thereto.

[0050] In some preferred embodiments, the molar ratio of the metal salt precursor to the organic ligand is 1 to 20:1, preferably 1 to 10:1.

[0051] In some preferred embodiments, the organic ligand may include any one or a combination of two or more of pyromellitic acid, terephthalic acid, pyridine carboxylic acid ligands, but is not limited thereto.

[0052] In some preferred embodiments, the organic solvent may include any one or a combination of two or more of ethanol, methanol, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, etc., but is not limited thereto.

[0053] In some preferred embodiments, the preparation method of the supported metal-organic framework catalyst specifically includes: adding the metal salt solution or complexed metal salt solution to the mother liquor of the synthetic metal-organic framework organic solvent, and carrying out the hydrothermal reaction in a closed environment at 30-180°C for 5-96 hours, after which the obtained powder solid particles are washed and dried; preferably, the hydrothermal reaction temperature is 80-140°C and the time is 10-48 hours.

[0054] In some preferred embodiments, the preheating treatment includes calcination in a selected gas atmosphere, preferably air or nitrogen.

[0055] In some more preferred embodiments, the calcination process is carried out in an air atmosphere, the calcination temperature is 100–400°C, and the calcination time is 1–10 h.

[0056] In some more preferred embodiments, the calcination treatment is carried out in a nitrogen atmosphere, the calcination temperature is 100–400°C, the calcination time is 1–10 h, and the nitrogen space velocity for the metal-organic framework material is 10,000–35,000 h⁻¹. -1 .

[0057] In some preferred embodiments, the preparation method of the supported metal-organic framework catalyst specifically includes the following steps: (1) dissolving the metal salt precursor directly in an aqueous solution or an organic solution to obtain an aqueous solution of the metal salt or an organic solution of the complexed metal salt; (2) adding the aqueous solution of the metal salt or the organic solution of the complexed metal salt to the reaction mother liquor containing organic ligands for synthesizing MOFs materials, performing closed hydrothermal reaction treatment, cooling, washing and drying; (3) calcining the dried metal-organic framework catalyst obtained above in an air atmosphere and / or a nitrogen atmosphere at a certain temperature to obtain the supported metal-organic framework catalyst.

[0058] The preparation principle of this invention may be that the synthesis environment of metal-organic framework materials is generally acidic, and the metal precursor can be completely dissolved in the solution under these conditions. The ligand can stabilize the precursor and keep it in a stable state, thus enabling the control of its stable loading and particle size.

[0059] Another aspect of the present invention provides a supported metal-organic framework catalyst prepared by the aforementioned method, comprising a metal-organic framework material and metal clusters or metal nanoparticles, wherein the metal clusters or metal nanoparticles are uniformly distributed on the surface and within the pore structure of the metal-organic framework material.

[0060] In some preferred embodiments, the content of metal nanoparticles in the supported metal-organic framework catalyst is 0.01 to 5 wt%.

[0061] In some preferred embodiments, the porosity of the metal-organic framework material is 5% to 50%, and the pore size of the contained channels is 0.1 to 1.5 nm.

[0062] In some preferred embodiments, the size of the metal nanoparticles is 0.3 to 5 nm.

[0063] Another aspect of the present invention provides the application of the aforementioned supported metal-organic framework catalyst in the catalytic methanol steam reforming reaction.

[0064] Another aspect of the present invention provides a method for methanol steam reforming reaction, comprising:

[0065] Provides a gas stream containing methanol and water vapor;

[0066] The gas stream is brought into contact with the aforementioned supported metal-organic framework catalyst at 100–300°C to achieve methanol steam reforming for hydrogen production.

[0067] In summary, the preparation method of the supported metal-organic framework catalyst for catalytic methanol reforming to produce hydrogen of the present invention is simple, and the prepared supported metal-organic framework catalyst has the advantages of being non-toxic, low-cost, highly active, and long-lived. It can be used for on-board methanol reforming to produce hydrogen and has broad application prospects.

[0068] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be further described in detail below with reference to the accompanying drawings and several preferred embodiments. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. For test methods in the following embodiments where specific conditions are not specified, the test methods in the embodiments are all performed under conventional conditions. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0069] Example 1

[0070] In this embodiment, the ZnAl@HKUST-1 (MOFs) catalyst uses zinc nitrate, aluminum nitrate, copper nitrate, pyromellitic acid, ethanol, and deionized water as raw materials. The molar ratio of aluminum nitrate, zinc nitrate, copper nitrate, pyromellitic acid, H2O, and ethanol is 1.0:2.0:2.0:1.0:1500: The preparation process of ZnAl@HKUST-1 metal-organic framework catalyst is as follows: (1) Zinc nitrate, aluminum nitrate, copper nitrate and deionized water are mixed and stirred to fully dissolve to obtain solution A; (2) Tris(2) Tris(2) pyromellitic acid is dissolved in ethanol and stirred to fully dissolve, and then stirred evenly to obtain MOF synthesis mother liquor B; (3) Solution A is added to mother liquor B and stirred for 1 hour, then transferred to a hydrothermal reactor and hydrothermally crystallized at 100°C for 12 hours; (4) The product in the hydrothermal reactor is washed three times with ethanol and water respectively, and then dried at 80°C for 8 hours. Then it is heated to 250°C and kept at a heating rate of 2°C / min in air atmosphere for 3 hours to obtain product ZnAl@HKUST-1 metal-organic framework catalyst material.

[0071] The TEM and XRD patterns of the ZnAl@HKUST-1 metal-organic framework catalyst material obtained in this embodiment can be found in the reference. Figure 1a , Figure 1b and Figure 2 As shown, by Figure 1a , Figure 1b and Figure 2 Analysis shows that the ZnAl@HKUST-1 metal-organic framework catalyst material synthesized in this embodiment has an octahedral regular morphology and a small size. The supported metal active centers are uniformly dispersed, and the XRD diffraction peaks are completely consistent with the simulated peaks, proving that the HKUST-1 crystal structure was synthesized.

[0072] Example 3

[0073] In this embodiment, the CuAl@MOF-5 metal-organic framework catalyst uses aluminum nitrate, copper nitrate, zinc nitrate, and terephthalic acid as raw materials, and N,N-dimethylformamide (DMF) and deionized water as solvents. The molar ratio of aluminum nitrate, copper nitrate, zinc nitrate, terephthalic acid, H2O, and DMF is 1.0: 1.0: 2.0: 1.0: 400: The preparation process of CuAl@MOF-5 metal-organic framework catalyst is as follows: (1) Aluminum nitrate, copper nitrate, zinc nitrate and deionized water are mixed and stirred to fully dissolve to obtain solution A; (2) Terephthalic acid is dissolved in DMF and stirred to fully dissolve to obtain crystal synthesis solution B; (3) Solution A is added to synthesis solution B and stirred for half an hour, then transferred to a hydrothermal reactor for hydrothermal crystallization at 120℃ for 3 hours; (4) The product in the hydrothermal reactor is washed three times with water and dried in an oven at 80℃. Then it is heated to 300℃ and kept at a heating rate of 2℃ / min in air atmosphere for 3 hours to obtain product CuAl@MOF-5 metal-organic framework catalyst.

[0074] Example 4

[0075] In this embodiment, the Cu@ZIF-67 metal-organic framework catalyst uses copper nitrate, cobalt nitrate, and 2-methylimidazole as raw materials, and ammonia and deionized water as reaction solvents. The molar ratio of copper nitrate, cobalt nitrate, 2-methylimidazole, ammonia and deionized water is 1.0: 2.0: 1.0: 100: 500. The preparation process of Cu@ZIF-67 metal-organic framework catalyst is as follows: (1) Mix copper nitrate, cobalt nitrate and deionized water, stir to fully dissolve them to obtain solution A; (2) Dissolve 2-methylimidazole in ammonia water, stir to fully dissolve them to obtain MOF material synthesis mother liquor B; (3) Add solution A to mother liquor B, stir for 2 hours and then filter to obtain powder; (4) Wash the product powder with water 3 times and dry it at 60°C. Then heat it to 250°C at a heating rate of 2°C / min in air atmosphere and keep it at that temperature for 3 hours. After the heating is completed, cool it to obtain product Cu@ZIF-67 metal-organic framework catalyst.

[0076] Example 5

[0077] In this embodiment, the CuAl@UIO-66 metal-organic framework catalyst uses copper nitrate, aluminum nitrate, zirconium nitrate, and terephthalic acid as raw materials, acetic acid as a structure-directing agent, and N,N-dimethylformamide (DMF) and deionized water as reaction solvents. The molar ratio of copper nitrate, aluminum nitrate, zirconium nitrate, acetic acid, and DMF is 1.0: 1.0: 2.0: 10: 500 H2O : The preparation process of CuAl@UIO-66 metal-organic framework catalyst is as follows: (1) Mix copper nitrate, aluminum nitrate, zirconium nitrate and water, stir to fully dissolve to obtain solution A; (2) Dissolve acetic acid in DMF, then add terephthalic acid to the above solution and continue stirring to obtain MOFs synthesis mother liquor B; (3) Add solution A to mother liquor B, stir for 0.5 h, then transfer to a hydrothermal reactor and hydrothermally crystallize at 100℃ for 48 h; (4) Wash the product in the hydrothermal reactor three times with water and dry at 80℃, then heat to 300℃ and keep warm for 3 h at a heating rate of 2℃ / min in air atmosphere to obtain product CuAl@UIO-66 metal-organic framework catalyst.

[0078] Example 6

[0079] In this embodiment, the CuAl@MIL-101 (Fe) metal-organic framework catalyst uses copper chloride, aluminum chloride, ferric chloride, and terephthalic acid as raw materials, and N,N-dimethylformamide (DMF) and deionized water as reaction solvents. The molar ratio of copper chloride, aluminum chloride, ferric chloride, terephthalic acid, and DMF is 1.0:1.0:2.0:1.0: The preparation process of CuAl@MIL-101 metal-organic framework catalyst is as follows: (1) Mix copper chloride, aluminum chloride, ferric chloride and deionized water, stir to dissolve them completely to obtain solution A; (2) Dissolve terephthalic acid in DMF, stir to dissolve them completely to obtain molecular sieve synthesis mother liquor B; (3) Add solution A to mother liquor B, stir for 2 hours and then transfer to a hydrothermal reactor for hydrothermal crystallization at 110℃ for 20h; (4) Wash the product in the hydrothermal reactor three times with water and dry it at 80℃. Then heat it to 300℃ at a heating rate of 2℃ / min in a nitrogen atmosphere and keep it at that temperature for 1h. After the end, cool it to obtain the product CuAl@MIL-101 metal-organic framework catalyst.

[0080] Example 7

[0081] In this embodiment, the ZnAl@UIO-66-NH2 metal-organic framework catalyst uses zinc nitrate, aluminum nitrate, zirconium nitrate, and terephthalic acid as raw materials, and N,N-dimethylformamide (DMF) and deionized water as reaction solvents. The molar ratio of zinc nitrate, aluminum nitrate, zirconium nitrate, terephthalic acid, H2O, and DMF is 1.0: 1.0: 2.0: 1.0: 200: The preparation process of ZnAl@UIO-66-NH2 metal-organic framework catalyst is as follows: (1) Zinc nitrate, aluminum nitrate, zirconium nitrate and deionized water are mixed and stirred to fully dissolve to obtain solution A; (2) Terephthalic acid is dissolved in DMF and stirred to dissolve evenly to obtain MOFs synthesis mother liquor B; (3) Solution A is added to mother liquor B and stirred for 0.5 hours, then transferred to a hydrothermal reactor for hydrothermal crystallization at 100℃ for 24 hours; (4) The product in the hydrothermal reactor is washed three times with water and dried at 80℃, then heated to 250℃ and kept at a heating rate of 2℃ / min in a nitrogen atmosphere for 2 hours to obtain product ZnAl@UIO-66-NH2 metal-organic framework catalyst.

[0082] Example 8

[0083] In this embodiment, the CuAl@MIL-100 (Fe) metal-organic framework catalyst uses copper chloride, aluminum chloride, ferric nitrate, and pyromellitic acid as raw materials, and deionized water as the reaction solvent. The molar ratio of copper chloride, aluminum chloride, ferric nitrate, pyromellitic acid, and deionized water is 1.0: 1.0: 2.0: 1.0: The preparation process of CuAl@MIL-100 metal-organic framework catalyst is as follows: (1) Mix copper chloride, aluminum chloride, ferric nitrate and deionized water, stir to dissolve them completely to obtain solution A; (2) Dissolve pyromellitic acid in deionized water, stir to dissolve them completely to obtain synthesis MOFs mother liquor B; (3) Add solution A to mother liquor B, stir for 0.5 hours, then transfer to a hydrothermal reactor and hydrothermally crystallize at 150°C for 12 hours; (4) Wash the product in the hydrothermal reactor three times with water, dry it at 80°C, then heat it to 300°C at a heating rate of 2°C / min in a nitrogen atmosphere and keep it at that temperature for 2 hours. After the heating is completed, cool it to obtain the product CuAl@MIL-100 metal-organic framework catalyst.

[0084] Example 9

[0085] The ZnAl@HKUST-1 metal-organic framework (MOF) catalyst obtained in Example 1 was used to catalyze the methanol steam reforming reaction. The specific reaction conditions were as follows: in a fixed-bed tubular reactor, the water-to-ethanol molar ratio of the feed components was 1.0-3.0, the reaction temperature was 150℃-300℃, and the space velocity was 4000 h⁻¹. -1 .

[0086] The hydrogen yield in the methanol reforming hydrogen production reaction of this embodiment was compared with the hydrogen yield in the methanol reforming hydrogen production reaction using the commercial catalyst CuO / ZnO / Al2O3. The comparison results are shown in [link to comparison]. Figure 3 ,Depend on Figure 3 It can be seen that the ZnAl@HKUST-1 metal-organic framework catalyst material prepared in Example 1 has good reaction performance.

[0087] In summary, the preparation method of the supported metal-organic framework catalyst for catalyzing methanol steam reforming is simple. The prepared supported metal-organic framework catalyst has the advantages of being green and non-toxic, low cost, high activity, and long lifespan. It can be used for on-board methanol steam reforming to produce hydrogen and has broad application prospects.

[0088] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0089] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated otherwise, any use of the terms first, second, etc., does not indicate any order or importance, but is used to distinguish one element from another.

Claims

1. Application of ZnAl@HKUST-1 metal-organic framework catalyst in catalytic methanol steam reforming reaction. The ZnAl@HKUST-1 metal-organic framework catalyst uses zinc nitrate, aluminum nitrate, copper nitrate, pyromellitic acid, ethanol, and deionized water as raw materials. The molar ratio of aluminum nitrate, zinc nitrate, copper nitrate, pyromellitic acid, H2O, and ethanol is 1.0:2.0:2.0:1.0:1500:2000. The preparation process of the ZnAl@HKUST-1 metal-organic framework catalyst is as follows: (1) Zinc nitrate, aluminum nitrate, copper nitrate, and deionized water are mixed and stirred to fully dissolve them to obtain solution A; ( 2) Dissolve pyromellitic acid in ethanol, stir until fully dissolved, and continue stirring until homogeneous to obtain MOF synthesis mother liquor B; (3) Add solution A to mother liquor B, stir for 1 hour, and then transfer to a hydrothermal reactor for hydrothermal crystallization at 100°C for 12 hours; (4) Wash the product in the hydrothermal reactor three times with ethanol and water respectively, and then dry it at 80°C for 8 hours. Then heat it to 250°C and keep it at a heating rate of 2°C / min in air atmosphere for 3 hours to obtain ZnAl@HKUST-1 metal-organic framework catalyst.

2. A method for methanol steam reforming reaction, characterized in that, include: Provides a gas stream containing methanol and water vapor; The gas stream is brought into contact with a supported metal-organic framework catalyst at 100–300°C to achieve methanol steam reforming for hydrogen production. The supported metal-organic framework catalyst is a ZnAl@HKUST-1 metal-organic framework catalyst. The ZnAl@HKUST-1 metal-organic framework catalyst uses zinc nitrate, aluminum nitrate, copper nitrate, pyromellitic acid, ethanol and deionized water as raw materials. The molar ratio of aluminum nitrate, zinc nitrate, copper nitrate, pyromellitic acid, H2O and ethanol is 1.0:2.0:2.0:1.0:1500:2000. The preparation process of ZnAl@HKUST-1 metal-organic framework catalyst is as follows: (1) Zinc nitrate, aluminum nitrate, copper nitrate and deionized water are used as raw materials. (1) Mix and stir to fully dissolve to obtain solution A; (2) Dissolve pyromellitic acid in ethanol, stir to fully dissolve, and continue stirring to obtain MOF synthesis mother liquor B; (3) Add solution A to mother liquor B, stir for 1 hour, and then transfer to a hydrothermal reactor for hydrothermal crystallization at 100°C for 12 hours; (4) Wash the product in the hydrothermal reactor three times with ethanol and water respectively, and then dry it at 80°C for 8 hours. Then heat it to 250°C and keep it at a heating rate of 2°C / min in air atmosphere for 3 hours to obtain ZnAl@HKUST-1 metal-organic framework catalyst.

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