A defective polyacid-based metal organic framework catalyst and its preparation and application

Abstract

The present invention provides a defective polyacid-based metal organic framework catalyst and its preparation and application. The defective catalyst is achieved by in-situ introduction of a monodentate organic carboxylic acid or an inorganic oxygen-containing acid as a regulator during the synthesis of the metal organic framework, and the in-situ induction of the coordinated unsaturated site is achieved by the interaction between the regulator and the metal atom / cluster node. The defective polyacid-based metal organic framework provided by the present invention combines the respective advantages of polyacids and coordinated unsaturated metal organic framework catalysts, and realizes the synergistic catalytic effect of polyacids and defective sites, and has the characteristics of simple synthesis method and easy recovery of catalyst, which is conducive to large-scale industrial application. This type of catalyst has shown excellent performance beyond traditional metal organic framework catalysts in the semi-hydrogenation of acetylene and the preparation of γ-valerolactone from levulinic acid.

Description

Technical Field

[0001] The invention belongs to the technical field of catalytic material preparation, and specifically relates to a defective polyacid-based metal organic framework catalyst and a preparation method and application thereof. Background Art

[0002] Polyoxometalates, also known as polyacids (POM), are a class of excellent molecular catalysts with strong BrΦnsted acidity, reversible redox properties, stable structure, and adjustable performance. POM is easily soluble in polar solvents, making it difficult to recycle and reuse; it is easy to agglomerate in non-polar solvents, resulting in a small specific surface area (<10m 2 g -1 ), cannot fully expose the catalytic active sites, limiting its catalytic performance. Supported polyacid-based catalysts can achieve heterogeneity of polyacid catalysts and make full use of the catalytic active sites of POM itself. In recent years, metal organic frameworks (MOFs) have become an excellent catalyst carrier due to their rich composition structures, adjustable pore sizes and large specific surface areas. Among them, polyacid-based metal organic framework materials (POM@MOF) combine the structural and performance advantages of POM and MOF, showing good catalytic performance. However, in traditional POM@MOF materials, polyacids usually act as a single catalytic active center, and the MOF skeleton only acts as a carrier, and the applicable reaction types are limited. However, catalytic reactions usually face the simultaneous activation of multiple reaction substrates or the continuous activation of multi-step intermediates. Therefore, designing and constructing catalysts with multiple active centers is of great significance to achieve synergistic or tandem catalysis and develop efficient catalytic materials. Summary of the invention

[0003] The purpose of the present invention is to provide a defective polyacid-based metal organic framework catalyst and a preparation method and application thereof.

[0004] A defective polyacid-based metal organic framework catalyst D-POM@MOF material, which contains a porous metal organic framework material MOF and a polyacid. By in-situ introducing a monodentate organic carboxylic acid or an inorganic oxygen-containing acid as a regulator during the synthesis of the metal organic framework material, a defective polyacid-based metal organic framework is inducing in situ, wherein the defect site is located on the skeleton of the metal organic framework material, and the polyacid is located in the pores of the metal organic framework material.

[0005] The MOF is a three-dimensional porous metal organic framework material, which can be selected from any metal organic framework material with a pore size of 0.5-5 nm, preferably 0.5-2 nm. The embodiment of the present invention uses UiO-66 and HKUST-1 materials.

[0006] Among the materials, the Keggin type saturated polyacid is dodecaptungstophosphoric acid (chemical formula is H3PW 12 O40 ), dodecamolybdic acid (chemical formula H3PMo 12 O 40 ), dodeca-tungstosilicic acid (chemical formula: H4SiW 12 O 40 ) at least one; Keggin type vacancy polyacid is nine tungstophosphoric acid (chemical formula H9PW9O 34 ), nonamphoric acid (chemical formula H9PMo9O 34 ), nonatungstosilicic acid (chemical formula: H 10 sIo 34 ) at least one of the following; Dawson type saturated polyacid is 18-tungsten diphosphoric acid (chemical formula H6P2W 18 O 62 ), 18-molybdenum diphosphate (chemical formula H6P2Mo 18 O 62 ), 18-tungsten disilicate acid (chemical formula: H 16 s2W 18 O 66 ) at least one of the following; Dawson type vacancy polyacid is pentadecaneditungstic diphosphoric acid (chemical formula is H 12 P2W 15 O 56 ); the loading amount of the polyacid in the MOF material is 5-70wt%, preferably 20-50wt%.

[0007] Due to the high porosity and structural stability of metal-organic framework materials, polyacids can directly interact with metal cluster nodes under the action of regulators or by selecting polyacid clusters of comparable size, thereby disrupting the crystallization process of the MOF skeleton and being evenly dispersed in the framework to construct D-POM@MOF materials.

[0008] The D-POM@MOF material is D-PW 12 @HKUST-1、D-PMo 12 @HKUST-1、D-SiW 12 @HKUST-1、D-SiMo 12 @HKUST-1, D-PW9@HKUST-1, D-PMo9@HKUST-1, D-SiW9@HKUST-1, D-PW 12 @UiO-66、D-PMo 12 @UiO-66、D-SiW 12 @UiO-66, D-P2W 18 @UiO-66, D-P2Mo 18 @UiO-66、D-Si2W 18@UiO-66, D-PW9@UiO-66, D-PMo9@UiO-66, D-SiW9@UiO-66, D-P2W 15 @UiO-66; PW 12 Indicates H3PW 12 O 40 , PMo 12 H3PMo 12 O 40 , SiW 12 Represents H4SiW 12 O 40 , P2W 18 Indicates H6P2W 18 O 62 , P2Mo 18 Indicates H6P2Mo 18 O 62 , Si2W 18 Indicates H 16 s2W 18 O 66 , PW9 means H9PW9O 34 , PMo9 represents H9PMo9O 34 、SiW9 represents H 10 sIo 34 , P2W 15 Indicates H 12 P2W 15 O 56 , D indicates that there are defects in the material.

[0009] The present invention also provides a method for preparing the above-mentioned D-POM@MOF material or catalyst, which comprises: (1) using a monodentate organic carboxylic acid or an inorganic oxygen-containing acid as a regulator, introducing the regulator into the synthesis process of the metal organic framework material, in situ inducing coordination unsaturated sites, and then selecting whether to remove the regulator as needed to synthesize the D-POM@MOF material; (2) in situ inducing the formation of coordination unsaturated sites by polyacids, thereby constructing the D-POM@MOF material.

[0010] Specifically, the following steps are included: dissolving the metal ions, organic ligands and polyacids constituting the metal organic framework in a solvent, stirring and mixing evenly with or without adding a regulator, separating and recovering the sample after the reaction, and selecting whether to remove the regulator by heating as needed (the regulator can be removed or not) to obtain D-POM@MOF materials or catalysts. Among them, the molar ratio of metal ions, organic ligands and polyacids is 4:2:1 to 2:1:7, preferably 4:2:5 to 2:1:5; the ratio of metal ions to regulators is 4-2mol:0.5-2mL; in the two types of materials, D-POM@HKUST needs to add a regulator, and the pH of the reaction system is controlled to 2-3, and the regulator needs to be removed after the reaction, while D-POM@UiO-66 does not need to add a regulator, nor does it need to remove the regulator.

[0011] The metal ion is at least one of Zr and Cu; the organic ligand is at least one of terephthalic acid and trimesic acid; the solvent is selected according to the solubility of the raw materials, preferably at least one of water, methanol, ethanol, and N,N'-dimethylformamide; the regulator is selected according to the coordination situation, preferably at least one of formic acid, acetic acid, trifluoroacetic acid, benzoic acid, isopoly acid or heteropoly acid.

[0012] The three-dimensional porous metal organic framework can be selected from any metal organic framework material, and its pore size is 0.5-5nm, preferably 0.5-2nm. The embodiment of the present invention uses UiO-66 and HKUST-1 materials, wherein the loading amount of the polyacid is 5-70wt%.

[0013] The method of in-situ synthesis by adding a regulator is to select a suitable regulator and synthesize D-POM@MOF by in-situ hydrothermal, solvothermal, or other conventional synthesis methods except hydrothermal and solvothermal; wherein the polyacid is added before the MOFs synthesis process or simultaneously with the regulator to enter the porous channels of the MOFs to achieve in-situ induction of the coordination unsaturated sites; the regulator can be added before or during the MOF synthesis process.

[0014] The in-situ synthesis is carried out at room temperature or in a high temperature oven; the temperature is 25-200°C, preferably 25-150°C, and the time is 30-1440 min, preferably 60-1440 min. As needed, the obtained D-POM@MOF material is dried in an oven at 60-100°C for 24-48 hours to remove the regulator.

[0015] The present invention further provides the use of D-POM@MOF catalyst for catalyzing the semi-hydrogenation reaction of acetylene. 12 @HKUST-1 catalyst is used to catalyze the semi-hydrogenation reaction of acetylene. The reaction equation is as follows:

[0016]

[0017] Also provided is the use of a D-POM@MOF catalyst for catalyzing the preparation of γ-valerolactone from levulinic acid. 18 @UiO-66 catalyst is used to catalyze the preparation of γ-valerolactone from levulinic acid. The reaction equation is as follows:

[0018]

[0019] The D-POM@MOF material is as defined above.

[0020] Beneficial effects: The defective catalyst of the present invention is prepared by in-situ introduction of monodentate organic carboxylic acid or inorganic oxygen-containing acid as a regulator during the synthesis of the metal organic framework, and the in-situ induction of the coordination unsaturated sites is achieved by utilizing the interaction between the regulator and the metal atom / cluster node. The defective polyacid-based metal organic framework provided by the present invention combines the respective advantages of polyacids and coordination unsaturated metal organic framework catalysts, and realizes the synergistic catalytic effect of polyacids and defective sites. The D-POM@MOF material provided by the present invention has the characteristics of multiple active center sites, simple synthesis method, more stability than traditional defective MOF, and easy catalyst recovery, which is conducive to large-scale industrial application. This type of catalyst has shown excellent performance that exceeds traditional metal organic framework catalysts in the semi-hydrogenation of acetylene and the preparation of γ-valerolactone from levulinic acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The scanning electron microscope spectrum of the defective polyacid-based metal organic framework material described in Example 1 of the present invention;

[0022] Figure 2 The transmission electron microscopy spectrum of the defective polyacid-based metal organic framework material described in Example 7 of the present invention;

[0023] Figure 3 This is a scanning electron microscope image of the defective polyacid-based metal organic framework material described in Example 8 of the present invention;

[0024] Figure 4 The scanning electron microscope spectrum of the defective polyacid-based metal organic framework material described in Example 9 of the present invention;

[0025] Figure 5 This is a scanning electron microscope image of the defective polyacid-based metal organic framework material described in Example 10 of the present invention;

[0026] Figure 6 This is a scanning electron microscope image of the defective polyacid-based metal organic framework material described in Example 11 of the present invention;

[0027] Figure 7This is a scanning electron microscope image of the defective polyacid-based metal organic framework material described in Example 12 of the present invention;

[0028] Figure 8 This is a scanning electron microscope image of the defect-free metal organic framework material described in Comparative Example 4 of the present invention;

[0029] Fig. 9 CD3CN infrared spectra of the materials described in Examples 1, 7, 8, 9, 10, 11, 12, Comparative Example 1, and Comparative Example 4 of the present invention;

[0030] Fig.10 X-ray absorption spectra (XAS) of the materials described in Example 1 and Comparative Example 1 of the present invention;

[0031] Fig.11 X-ray absorption spectra (XAS) of the materials described in Examples 7, 8, 9, 10, 11, 12, 13, 14, and 15 of the present invention;

[0032] Fig.12 The results of the acetylene semi-hydrogenation reaction catalyzed by the defective metal organic framework catalyst in Example 1 of the present invention, wherein the orange-yellow column represents the conversion rate of different catalysts for the reaction;

[0033] Fig.13 The results of the reaction of preparing γ-valerolactone by hydrogenation cyclization of levulinic acid catalyzed by the defective metal organic framework catalyst in Example 2 of the present invention are shown, wherein the orange column represents the selectivity of generating γ-valerolactone; the green and purple colors represent the selectivity of the first and second by-products, respectively. DETAILED DESCRIPTION

[0034] The preparation method of the D-POM@MOF catalyst provided by the present invention is described in detail below with reference to specific examples.

[0035] Glossary:

[0036] Polyoxometalates, also known as polyoxometalates (POMs), are nanoscale metal oxygen cluster compounds formed by pre-transition metal ions (such as V, Mo, W, Nb, Ta, etc.) and oxygen.

[0037] Metal-organic framework materials (MOF) are a type of porous solid molecular materials with periodic network structures formed by the coordination between metal atoms or metal clusters as nodes and organic bridging ligands as connectors. Among them, UiO-66 is a metal-organic framework material with Zr6O8 as metal cluster nodes and terephthalic acid as ligands; HKUST-1 is a metal-organic framework material with Cu as metal nodes and trimesic acid as ligands.

[0038] D-POM@MOF materials, @ indicates that the polyacid exists in the pores of MOF and is wrapped by MOF, and D indicates that POM@MOF has defect sites. D-POM@MOF materials include D-PW 12 @HKUST-1、D-PMo 12 @HKUST-1、D-SiW 12 @HKUST-1, D-PW9@HKUST-1, D-PMo9@HKUST-1, D-SiW9@HKUST-1, D-PW 12 @UiO-66、D-PMo 12 @UiO-66、D-SiW 12 @UiO-66, D-P2W 18 @UiO-66, D-P2Mo 18 @UiO-66 or D-Si2W 18 @UiO-66, D-PW9@UiO-66, D-PMo9@UiO-66, D-SiW9@UiO-66, D-P2W 15 @UiO-66; PW 12 It is the abbreviation of dodecatungstophosphoric acid, and its chemical formula is H3PW 12 O 40 ;PMo 12 It is the abbreviation of dodecamolybdic acid, and its chemical formula is H3PMo 12 O 40 ;SiW 12 It is the abbreviation of dodecatungstosilicic acid, and its chemical formula is H4SiW 12 O 40 ;P2W 18 It is the abbreviation of 18-tungsten diphosphoric acid, and its chemical formula is H6P2W 18 O 62 ;P2Mo 18 It is the abbreviation of 18molybdenum diphosphate, and its chemical formula is H6P2Mo 18 O 62 ;Si2W 18 It is the abbreviation of 18tungsten disilicate, and its chemical formula is H 16 s2W 18 O 66 ; PW9 is the abbreviation of nonatungstophosphoric acid, and its chemical formula is H9PW9O 34 ; PMo9 is the abbreviation of nonamolybdenum phosphoric acid, and its chemical formula is H9PMo9O 34 ; SiW9 is the abbreviation of nonatungstosilicic acid, and its chemical formula is H 10 sIo 34 ;P2W 15 It is the abbreviation of pentadecatungstic diphosphoric acid, and its chemical formula is H 12 P2W 15 O56 .

[0039] The reaction tube used in Application Example 1 is a commercially available reaction tube selected from the Hinwell reaction tube, model F891410, and other reaction tubes may also be used; the high-pressure reactor used in Application Example 2 is a commercially available instrument selected from the Yanzheng Instrument, model YZPR-100, and other reactors may also be used.

[0040] Example 1

[0041] Weigh 0.24g of copper nitrate trihydrate and dissolve it in 10mL of deionized water, add 2mL of acetic acid, stir for 30min, then add 0.58g of dodecaptungstophosphoric acid, and adjust the pH to 2.5 with 1M sodium hydroxide solution after complete dissolution, recorded as solution A. Dissolve 0.14g of trimesic acid in 10mL of anhydrous ethanol, recorded as solution B. In a 60℃ oil bath, add solution B dropwise to solution A and continue stirring for 30min. Collect the precipitate by filtration and wash it 3 times with water, then 3 times with ethanol, and then wash it with ethanol and water. The collected solid was exchanged in chloroform 3 times, each exchange time was 12h, exchanged in chloroform 3 times, washed and dried at 80℃ for 24h to obtain a defective polyacid-based metal-organic framework material (referred to as D-PW 12 @HKUST-1). The obtained product was characterized by scanning electron microscopy, CD3CN infrared and X-ray absorption spectroscopy (XAS). Figure 1 As shown, D-PW can be observed 12 The basic appearance of @HKUST-1; Fig. 9 As shown, D-PW 12 @HKUST-1 There are obvious vibration peaks around, indicating that defective metal organic framework catalysts have been obtained; Fig.10 As shown, the main peak is located at This peak is considered to be the contribution of Cu-O bond; D-PW 12 The peak intensity of HKUST-1 is obviously lower than that of the fully coordinated PW 12 @HKUST-1, confirmed that the coordination number of Cu in the material was reduced, that is, the defective metal organic framework catalyst D-PW was formed 12 @HKUST-1.

[0042] Example 2 Weigh 0.24g of copper nitrate trihydrate and dissolve it in 10mL of deionized water, add 2mL of acetic acid, stir for 30min, then add 0.58g of dodecamolybdate phosphate, and adjust the pH to 2.5 with 1M sodium hydroxide solution after complete dissolution, recorded as solution A. Dissolve 0.14g of trimesic acid in 10mL of anhydrous ethanol, recorded as solution B. In a 60°C oil bath, add solution B dropwise to solution A and continue stirring for 30min. Collect the precipitate by filtration and wash it three times with water, then three times with ethanol. The collected solid is exchanged in chloroform three times, each exchange time is 12h, and then dried at 80°C for 24h after washing to obtain a defective polyacid-based metal-organic framework material (referred to as D-PMo 12 @HKUST-1).

[0043] Example 3

[0044] Weigh 0.24g of copper nitrate trihydrate and dissolve it in 10mL of deionized water, add 2mL of acetic acid, stir for 30min, then add 0.58g of dodecatungstosilicic acid. After complete dissolution, adjust the pH to 2.5 with 1M sodium hydroxide solution, recorded as solution A. Dissolve 0.14g of trimesic acid in 10mL of anhydrous ethanol, recorded as solution B. In a 60℃ oil bath, add solution B dropwise to solution A and continue stirring for 30min. Collect the precipitate by filtration and wash it 3 times with water, then 3 times with ethanol. The collected solid is exchanged in chloroform 3 times, each exchange time is 12h, and then dried at 80℃ for 24h after washing to obtain a defective polyacid-based metal organic framework material (referred to as D-SiW 12 @HKUST-1).

[0045] Example 4

[0046] Weigh 0.24g of copper nitrate trihydrate and dissolve it in 10mL of deionized water, add 2mL of acetic acid, stir for 30min, then add 0.49g of nonatungstophosphoric acid, and adjust the pH to 2.5 with 1M sodium hydroxide solution after complete dissolution, which is recorded as solution A. Dissolve 0.14g of trimesic acid in 10mL of anhydrous ethanol, recorded as solution B. Add solution B dropwise to solution A in a 60℃ oil bath and continue stirring for 30min. Collect the precipitate by filtration and wash it 3 times with water, then 3 times with ethanol. The collected solid is exchanged in chloroform 3 times, each exchange time is 12h, and then dried at 80℃ for 24h to obtain a defective polyacid-based metal-organic framework material (referred to as D-PW9@HKUST-1).

[0047] Example 5

[0048] Weigh 0.24g of copper nitrate trihydrate and dissolve it in 10mL of deionized water, add 2mL of acetic acid, stir for 30min, then add 0.49g of nonamolybdophosphate, adjust the pH to 2.5 with 1M sodium hydroxide solution after complete dissolution, and record it as solution A. Dissolve 0.14g of trimesic acid in 10mL of anhydrous ethanol, record it as solution B. Add solution B dropwise to solution A in a 60℃ oil bath and continue stirring for 30min. Collect the precipitate by filtration and wash it 3 times with water, then 3 times with ethanol. The collected solid is exchanged in chloroform 3 times, each exchange time is 12h, and then dried at 80℃ for 24h after washing to obtain a defective polyacid-based metal organic framework material (referred to as D-PMo9@HKUST-1).

[0049] Example 6

[0050] Weigh 0.24g of copper nitrate trihydrate and dissolve it in 10mL of deionized water, add 2mL of acetic acid, stir for 30min, then add 0.49g of nonatungstosilicic acid, and adjust the pH to 2.5 with 1M sodium hydroxide solution after complete dissolution, which is recorded as solution A. Dissolve 0.14g of trimesic acid in 10mL of anhydrous ethanol, recorded as solution B. Add solution B dropwise to solution A in a 60℃ oil bath and continue stirring for 30min. Collect the precipitate by filtration and wash it with water 3 times and ethanol 3 times respectively. The collected solid is exchanged in chloroform 3 times, each exchange time is 12h, and dried at 80℃ for 24h to obtain a defective polyacid-based metal-organic framework material (referred to as D-SiW9@HKUST-1).

[0051] Example 7

[0052] Weigh 1.0g zirconium tetrachloride, 0.42g terephthalic acid and 1.0g 18tungsten diphosphoric acid and dissolve in 30mL N, N'-dimethylformamide and stir for 4h. Transfer the mixed solution to a reactor and react at 120℃ for 12h to obtain a solid product. First wash it with DMF 3 times, then wash it with distilled water 3 times, and then dry it at 80℃ for 24h to obtain a defective polyacid-based metal organic framework material (denoted as D-P2W 18 @UiO-66). The obtained product was characterized by transmission electron microscopy, CD3CN infrared and X-ray absorption spectroscopy (XAS). Figure 2 As shown in Figure 2, the obtained samples have no obvious cluster formation; Fig. 9 As shown, D-P2W 18 @UiO-66 at 2299cm -1 There are obvious vibration peaks on the left and right, indicating that a defective metal organic framework catalyst has been obtained; Fig.11 As shown, the main peak is located at This peak is considered to be the contribution of the Zr-O bond; P2W 18The intensity of the Zr-O peak in @UiO-66 is significantly reduced, confirming that the coordination number of Zr in the material is reduced, that is, the defective metal organic framework catalyst D-P2W is formed. 18 @UiO-66.

[0053] Example 8

[0054] Weigh 1.0g zirconium tetrachloride, 0.42g terephthalic acid and 0.7g dodecatungstophosphoric acid and dissolve in 30mL N, N'-dimethylformamide and stir for 4h. Transfer the mixed solution to a reactor and react at 120℃ for 12h to obtain a solid product. First wash it with DMF 3 times, then wash it with distilled water 3 times, and then dry it at 80℃ for 24h to obtain a defective polyacid-based metal organic framework material (denoted as D-PW 12 @UiO-66). The obtained product was characterized by scanning electron microscopy, CD3CN infrared and X-ray absorption spectroscopy (XAS). Figure 3 As shown, the obtained samples exhibited good morphology; Fig. 9 As shown, the sample is at 2299cm -1 There are obvious vibration peaks around, indicating that a defective metal organic framework is obtained; Fig.11 As shown in Figure 2, the intensity of the Zr-O peak of the synthesized material is significantly reduced, confirming that the coordination number of Zr in the material is reduced, that is, a defective metal organic framework catalyst D-PW is formed. 12 @UiO-66.

[0055] Example 9

[0056] Weigh 1.0g zirconium tetrachloride, 0.42g terephthalic acid and 0.7g dodecamolybdate phosphoric acid and dissolve in 30mL N,N'-dimethylformamide and stir for 4h. Transfer the mixed solution to a reactor and react at 120℃ for 12h to obtain a solid product. First wash it with DMF 3 times, then wash it with distilled water 3 times, and then dry it at 80℃ for 24h to obtain a defective polyacid-based metal organic framework material (denoted as D-PMo 12 @UiO-66). The obtained product was characterized by scanning electron microscopy, CD3CN infrared and X-ray absorption spectroscopy (XAS). Figure 4 As shown, the obtained samples exhibited good morphology; Fig. 9 As shown, the sample is at 2299cm -1 There are obvious vibration peaks around, indicating that a defective metal organic framework is obtained; Fig.11 As shown in Figure 2, the intensity of the Zr-O peak of the synthesized material is significantly reduced, confirming that the coordination number of Zr in the material is reduced, that is, a defective metal organic framework catalyst D-PMo is formed. 12 @UiO-66.

[0057] Example 10

[0058] Weigh 1.0g zirconium tetrachloride, 0.42g terephthalic acid and 0.7g dodecatungstosilicic acid and dissolve them in 30mL N,N'-dimethylformamide and stir for 4h. Transfer the mixed solution to a reactor and react at 120℃ for 12h to obtain a solid product. First wash it with DMF 3 times, then wash it with distilled water 3 times, and then dry it at 80℃ for 24h to obtain a defective polyacid-based metal organic framework material (denoted as D-SiW 12 @UiO-66). The obtained product was characterized by scanning electron microscopy, CD3CN infrared and X-ray absorption spectroscopy (XAS). Figure 5 As shown, the obtained samples exhibited good morphology; Fig. 9 As shown, the sample is at 2299cm -1 There are obvious vibration peaks around, indicating that a defective metal organic framework is obtained; Fig.11 As shown in Figure 2, the intensity of the Zr-O peak of the synthesized material is significantly reduced, confirming that the coordination number of Zr in the material is reduced, that is, a defective metal organic framework catalyst D-SiW is formed. 12 @UiO-66.

[0059] Embodiment 11

[0060] Weigh 1.0g zirconium tetrachloride, 0.42g terephthalic acid and 1.0g 18molybdenum diphosphate and dissolve in 30mL N,N'-dimethylformamide and stir for 4h. Transfer the mixed solution to a reactor and react at 120℃ for 12h to obtain a solid product. First wash it with DMF 3 times, then wash it with distilled water 3 times, and then dry it at 80℃ for 24h to obtain a defective polyacid-based metal organic framework material (denoted as D-P2Mo 18 @UiO-66). The obtained product was characterized by scanning electron microscopy, CD3CN infrared and X-ray absorption spectroscopy (XAS). Figure 6 As shown, the obtained samples exhibited good morphology; Fig. 9 As shown, the sample is at 2299cm -1 There are obvious vibration peaks around, indicating that a defective metal organic framework is obtained; Fig.11 As shown in Figure 2, the intensity of the Zr-O peak of the synthesized material is significantly reduced, confirming that the coordination number of Zr in the material is reduced, that is, a defective metal organic framework catalyst D-P2Mo is formed. 18 @UiO-66.

[0061] Example 12

[0062] Weigh 1.0g zirconium tetrachloride, 0.42g terephthalic acid and 1.0g 18-tungsten disilicate acid and dissolve them in 30mL N, N'-dimethylformamide and stir for 4h. Transfer the mixed solution to a reactor and react at 120℃ for 12h to obtain a solid product. First wash it with DMF 3 times, then wash it with distilled water 3 times, and then dry it at 80℃ for 24h to obtain a defective polyacid-based metal organic framework material (denoted as D-Si2W 18 @UiO-66). The obtained product was characterized by scanning electron microscopy, CD3CN infrared and X-ray absorption spectroscopy (XAS). Figure 7 As shown in Figure 2, the obtained samples all showed good morphology; Fig. 9 As shown, the sample is at 2299cm -1 There are obvious vibration peaks around, indicating that a defective metal organic framework is obtained; Fig.11 As shown in Figure 2, the intensity of the Zr-O peak of the synthesized material is significantly reduced, confirming that the coordination number of Zr in the material is reduced, that is, a defective metal organic framework catalyst D-Si2W is formed. 18 @UiO-66.

[0063] Embodiment 13

[0064] Weigh 1.0g zirconium tetrachloride, 0.42g terephthalic acid and 0.7g nonatungstophosphoric acid and dissolve in 30mL N, N'-dimethylformamide and stir for 4h. Transfer the mixed solution to a reactor and react at 120℃ for 12h to obtain a solid product. First wash it with DMF 3 times, then wash it with distilled water 3 times, and then dry it at 80℃ for 24h to obtain a defective polyacid-based metal organic framework material (denoted as D-PW9@UiO-66).

[0065] Embodiment 14

[0066] Weigh 1.0g zirconium tetrachloride, 0.42g terephthalic acid and 0.7g nonamolybdenum phosphoric acid and dissolve in 30mL N,N'-dimethylformamide and stir for 4h. Transfer the mixed solution to a reactor and react at 120℃ for 12h to obtain a solid product. First wash it with DMF 3 times, then wash it with distilled water 3 times, and then dry it at 80℃ for 24h to obtain a defective polyacid-based metal organic framework material (denoted as D-PMo9@UiO-66).

[0067] Embodiment 15

[0068] Weigh 1.0g zirconium tetrachloride, 0.42g terephthalic acid and 0.7g nonatungstosilicic acid and dissolve them in 30mL N,N'-dimethylformamide and stir for 4h. Transfer the mixed solution to a reactor and react at 120℃ for 12h to obtain a solid product. First wash it with DMF 3 times, then wash it with distilled water 3 times, and then dry it at 80℃ for 24h to obtain a defective polyacid-based metal organic framework material (denoted as D-SiW9@UiO-66).

[0069] Example 16

[0070] Weigh 1.0g zirconium tetrachloride, 0.42g terephthalic acid and 0.7g pentadecanedotungsten diphosphate and dissolve in 30mL N, N'-dimethylformamide and stir for 4h. Transfer the mixed solution to a reactor and react at 120℃ for 12h to obtain a solid product. First wash it with DMF 3 times, then wash it with distilled water 3 times and dry it at 80℃ for 24h to obtain a defective polyacid-based metal organic framework material (denoted as D-P2W 15 @UiO-66).

[0071] Comparative Example 1

[0072] Weigh 0.24g of copper nitrate trihydrate and dissolve it in 10mL of deionized water. After stirring for 30min, add 0.58g of dodecaptungstophosphoric acid. After it is completely dissolved, adjust the pH to 4 with 1M sodium hydroxide solution, which is recorded as solution A. Take 0.14g of trimesic acid and dissolve it in 10mL of anhydrous ethanol, which is recorded as solution B. In a 60℃ oil bath, add solution B dropwise to solution A. After the addition is completed, continue stirring for 30min, then filter the solid, wash it with water 3 times, then wash it with ethanol 3 times, wash it with water and ethanol, and collect the solid product by centrifugation. Dry it at 80℃ for 24h to obtain the polyacid-based metal organic framework material (referred to as PW 12 @HKUST-1). The obtained product was characterized by CD3CN infrared and X-ray absorption spectroscopy (XAS). Fig. 9 As shown, PW 12 @HKUST-1 at 2296cm -1 There is no obvious vibration peak. Fig.10 As shown, the material is in the main peak~ The peak intensity of the Cu-O bond at reflects the full coordination state of Cu, indicating that no defect site catalyst can be obtained in the absence of glacial acetic acid.

[0073] Comparative Example 2

[0074] Weigh 0.24g of copper nitrate trihydrate and dissolve it in 10mL of deionized water, add 2mL of acetic acid as a regulator, and record it as solution A. Dissolve 0.14g of trimesic acid in 10mL of anhydrous ethanol, and record it as solution B. Add solution B dropwise to solution A in a 60℃ oil bath, continue stirring for 30min after the addition is complete, then filter the solid, wash it with water and ethanol several times, and collect the solid product by centrifugation. Dry it at 80℃ for 24h to obtain the defective metal organic framework material (referred to as D-HKUST-1).

[0075] Comparative Example 3

[0076] Weigh 0.24g of copper nitrate trihydrate and dissolve it in 10mL of deionized water, which is called solution A. Dissolve 0.14g of trimesic acid in 10mL of anhydrous ethanol, which is called solution B. Add solution B dropwise to solution A in a 60℃ oil bath. After the addition is complete, continue stirring for 30min, filter the solid, and wash it with water and ethanol several times. Collect the solid product by centrifugation and dry it at 80℃ for 24h to obtain the metal organic framework material (referred to as HKUST-1).

[0077] Comparative Example 4

[0078] Weigh 1.0g zirconium tetrachloride and 0.42g terephthalic acid and dissolve them in 30mL DMF and stir for 20min. Transfer the mixed solution to a reactor and react at 120℃ for 24h to obtain a solid product. After being fully washed with DMF and distilled water, dry at 80℃ for 24h to obtain a metal organic framework material (denoted as UiO-66). The obtained product was characterized by scanning electron microscopy and CD3CN infrared. Figure 8 As shown, the obtained comparative sample has a good morphology; however, Fig. 9 As shown, UiO-66 is at 2299cm -1 There is no obvious vibration peak, indicating that there is no polyacid P2W 18 No defective site catalyst can be obtained when it exists.

[0079] Application Example 1

[0080] Catalytic acetylene semi-hydrogenation

[0081] The acetylene semi-hydrogenation reaction is carried out in a quartz fixed bed reactor. 300 mg of catalyst and 1 g of quartz sand (40-60 mesh) are uniformly mixed and loaded into the fixed bed reactor. The reaction gas contains 0.5 vol% C2H2, 5 vol% H2, 50 vol% C2H4, and He gas is used as the balance gas. The flow rate is 20 mL / min. The reactants and products are detected by gas chromatography, which needs to be stabilized for 10 minutes before testing. The detector is a FID detector.

[0082] In the application test, Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, PW 12 and PW 12 Compared with Comparative Example 2 (PW 12 The catalytic performance results of the six catalysts were shown in Figure 2. Fig.12 shown.

[0083] From the experimental test results, compared with the comparative catalyst, the D-PW of Example 1 12 @HKUST catalyst showed better conversion rate to acetylene.

[0084] Application Example 2

[0085] Reaction of Levulinic Acid to γ-Valerolactone

[0086] 2mmol of levulinic acid, 10mL of isopropanol and 200mg of catalyst were mixed and placed in a high pressure reactor, heated to 160°C for reaction, and reacted at normal pressure for 6h. The product was analyzed by gas chromatography-mass spectrometry.

[0087] In the application test, Example 3, Comparative Example 4, H6P2W were used respectively. 18 O 62 , and H6P2W 18 O 62 Compared with Comparative Example 4 (H6P2W 18 O 62 The catalytic performance results of the four catalysts physically blended with UiO-66 in a mass ratio of 1:3 are shown in Figure 2. Fig.13 shown.

[0088] From the experimental test results, compared with comparative example 4, H6P2W 18 O 62 、H6P2W 18 O 62 Compared with the catalyst physically blended with the catalyst of Comparative Example 4, the catalyst of Example 3 having defect sites shows excellent selectivity.

[0089] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A defective polyacid-based metal organic framework material, characterized in that: Containing MOF porous metal organic framework material and polyacid, the defect site is located on the skeleton of the metal organic framework material, and the polyacid is located in the pores of the metal organic framework material, recorded as D-POM@MOF; wherein the polyacid is a Keggin type or Dawson type saturated polyacid; The MOF is a porous metal organic framework material with a pore size of 0.5-5nm; The metal organic framework material is UiO-66; In the material, the Keggin type saturated polyacid is dodecatungstophosphoric acid H3PW 12 O 40 、Dodecamolybdate phosphate H3PMo 12 O 40 、Dodecatungstosilicate H4SiW 12 O 40 At least one of; Dawson type saturated polyacid is 18-tungsten diphosphate H6P2W 18 O 62 、Octadecamolybdenum diphosphate H6P2Mo 18 O 62 、Octadecanedotungstic disilicate H 16 s2W 18 O 66 At least one of the following; the loading amount of the polyacid in the MOF material is 5-70wt%; The preparation method of the defective polyacid-based metal organic framework material comprises the following steps: dissolving the metal ions, organic ligands and polyacid constituting the metal organic framework in a solvent, stirring and mixing evenly without adding a regulator, separating and recovering the sample after the reaction, and obtaining a defective polyacid-based metal organic framework catalyst; wherein the metal ion is Zr; the organic ligand is terephthalic acid; the solvent is at least one of water, ethanol and N,N′-dimethylformamide; the reaction temperature is 120°C and the reaction time is 12 hours.

2. The material according to claim 1, characterized in that The pore size of the porous metal organic framework material is 0.5-2nm.

3. The material according to claim 1, characterized in that The D-POM@MOF material is D-PW 12 @UiO-66、D-PMo 12 @UiO-66、D-SiW 12 @UiO-66, D-P2W 18 @UiO-66、D-P2Mo 18 @UiO-66、D-Si2W 18 @UiO-66 At least one of them.

4. A catalyst comprising the material according to any one of claims 1 to 3 as a catalyst, for catalyzing the semi-hydrogenation reaction of acetylene or the reaction of preparing γ-valerolactone from levulinic acid.

5. A method for semi-hydrogenation of acetylene, characterized in that: Using D-POM@MOF material as a catalyst, the reaction equation is as follows: The D-POM@MOF material is selected from any one of claims 1-3.

6. A method for the hydrogenation cyclization of levulinic acid, characterized in that: Using D-POM@MOF material as a catalyst, the reaction equation is as follows: The D-POM@MOF material is selected from any one of claims 1-3.

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