Method for loading metal nanoparticles on functionalized metal organic framework and catalytic application
By introducing functionalization regulators at the metal nodes of metal-organic frameworks, the aggregation problem of metal nanoparticles during the loading process was solved, achieving controllable size and uniformity, and improving catalytic performance and synthesis efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TAIYUAN UNIVERSITY OF TECHNOLOGY
- Filing Date
- 2026-01-12
- Publication Date
- 2026-04-28
AI Technical Summary
The high surface energy of existing metal nanoparticles on metal-organic frameworks leads to uneven aggregation, causing pore blockage and a reduction in active sites, which affects catalytic performance.
By introducing functionalization modifiers at the metal nodes of metal-organic frameworks, their coordination effect can be used to achieve precise anchoring and spatial confinement of metal nanoparticles, thereby controlling their size and uniformity.
It improves the dispersibility and size controllability of metal nanoparticles, enhances catalytic performance, simplifies the synthesis steps, and increases the synthesis success rate and functional group density.
Smart Images
Figure CN121927686A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of porous materials, specifically to a method for supporting metal nanoparticles on a functionalized metal-organic framework and its catalytic application. Background Technology
[0002] Currently, over 95% of chemical products worldwide are produced through specific catalytic processes, where the design and performance of metal catalysts play a decisive role in the efficiency, energy consumption, and environmental impact of these processes. Therefore, significant efforts are being made to develop high-performance metal catalysts. Among these, nanoscale metal catalysts, due to their unique physicochemical properties, exhibit superior performance and have attracted widespread attention. In recent years, metal nanoparticles, clusters, and single-atom-based catalysts have been discovered and used in various catalytic reactions. However, the atom utilization rate of existing metal nanoparticles is very limited, with only surface atoms participating in the catalytic reaction, resulting in most internal atoms being unable to function. Furthermore, while single-atom catalysts can maximize atom utilization efficiency, their inherent high surface energy makes them prone to migration and aggregation during preparation and reaction, forming nanoparticles of uneven size, leading to a decrease in active site density and a decline in catalytic performance. Therefore, developing metal catalysts with controllable size, small and uniform particle size is considered an effective way to improve atom economy, optimize catalytic reaction pathways, and enhance overall activity.
[0003] Metal-organic frameworks (MOFs) are ideal supports for loading and dispersing metal nanoparticle catalysts due to their excellent periodic porous structure. However, during the loading of metal nanoparticles onto MOFs, the high surface energy of atoms leads to easy growth and uneven distribution of the nanoparticles, causing pore blockage and a reduction in the number of effective active sites, thus limiting their catalytic performance. MOFs are self-assembled from metal nodes and ligands, exhibiting high structural tunability. Specific functional groups can be introduced into the framework, utilizing their unique coordination effects to anchor and spatially confine foreign metal species, thereby controlling the size and distribution of metal nanoparticle catalysts. Current research mainly focuses on grafting functional groups onto organic ligands to load metal nanoparticles, but this method faces problems such as cumbersome synthesis steps or difficulty in synthesis. Therefore, there is an urgent need to develop a simple method for functionalizing MOFs to achieve uniform loading of metal nanoparticles with controllable size and small particle size on MOF supports, thereby significantly improving their catalytic performance. Summary of the Invention
[0004] Conventional methods for loading metal nanoparticles onto metal-organic frameworks (MOFs) suffer from severe agglomeration due to the high surface energy of atoms. This results in large and non-uniform particle sizes, causing pore blockage and a reduction in the number of active sites within the MOF, significantly impacting catalytic performance. To address this issue, this invention provides a method for loading metal nanoparticles onto a functionalized MOF and its catalytic application.
[0005] This invention employs a strategy of directionally introducing coordinating functional groups at the metal nodes of a metal-organic framework, aiming to achieve precise anchoring and spatial confinement of metal nanoparticles, and effectively control their size and uniformity. This method has significant research value and application potential for developing high-performance catalytic material systems.
[0006] This invention directly involves functionalization modifiers in the assembly of metal-organic frameworks (MOFs), endowing MOFs with specific functional groups to load metal nanoparticles. Traditional post-modification methods require the replacement of existing modifiers, which are complex and costly. In contrast, this strategy not only simplifies the synthesis steps but also effectively improves the synthesis success rate and ligand modification density, providing a new approach for constructing well-defined and functionally enhanced MOF catalytic materials.
[0007] To achieve the above objectives, the present invention employs the following technical solution:
[0008] A method for loading metal nanoparticles onto a functionalized metal-organic framework includes the following steps:
[0009] Step 1: Mix the first metal salt, functionalization modifier, and solvent evenly, disperse them evenly by ultrasonication, and then perform the first heating to obtain the first solution.
[0010] Step 2: Mix the first solution with the ligand, disperse it evenly by ultrasonication to obtain the second solution, then heat it a second time. After the reaction is complete, cool and let it stand, then centrifuge and dry to obtain the functionalized metal-organic framework.
[0011] Step 3: The functionalized metal-organic framework is mixed with a solvent, ultrasonically dispersed, and then mixed with a second metal salt to obtain a third solution. After stirring, the solution is centrifuged, washed, and dried to finally achieve controllable loading of metal nanoparticles on the metal-organic framework.
[0012] The functional group modifier includes at least one of benzoic acid, isonicotinic acid, pyrrole-3-carboxylic acid, pyrazole-4-carboxylic acid, 1,2,4-triazole-3-carboxylic acid, p-fluorobenzoic acid, p-chlorobenzoic acid, p-bromobenzoic acid, p-hydroxybenzoic acid, p-aminobenzoic acid, p-mercaptobenzoic acid, 3-thiophenecarboxylic acid, 3-furanocarboxylic acid, 3-pyrrolecarboxylic acid, 4-ethynylbenzoic acid, 3,5-difluorobenzoic acid, 1H-benzimidazole-5-carboxylic acid, 3,4,5-trifluorobenzoic acid, 2,3,4,5,6-pentafluorobenzoic acid, and p-cyanobenzoic acid.
[0013] Preferably, the metal cation in the first metal salt is at least one of Zr, Hf, Ti, Co, Ni, Fe, Zn, Cu, Mg, Cd, Cr, Ce, Al, and Ca ions, and the anion is at least one of halide ions, nitrate ions, acetate ions, or sulfate ions.
[0014] Preferably, the solvent is at least one selected from N,N-dimethylformamide, dimethyl sulfoxide, N,N-diethylformamide, N-methylpyrrolidone, methanol, ethanol, water, acetone, dioxane, dichloromethane, ethyl acetate, diethyl ether, and acetone.
[0015] Preferably, the molar ratio of the first metal salt to the functionalization regulator is 1:10-50, and the temperature of the first heating is 25℃-300℃, and the time is 0.1h-200h.
[0016] Preferably, the ligand is at least one selected from 1,3,6,8-tetra(4-carboxyphenyl)pyrene, 1,3,5-tricarboxyphenylbenzene, 4,4',4'',4'''-(peryl-2,5,8,11-tetrayl)tetrabenzoic acid, neu-tetra(4-carboxyphenyl)porphyrin, 4,4',4'',4'''-(dibenzo[g, p]benzophenanthrene-2,7,10,15-tetrayl)tetrabenzoic acid, tetra[4-(4'-carboxyphenyl)phenyl]ethylene, 1,4-phthalic acid, 2-aminoterephthalic acid, 2-nitroterephthalic acid, biphenyl-4,4'-dicarboxylic acid, p-triphenyl-4,4'-dicarboxylic acid, pyromellitic acid, fumaric acid, 2-methylimidazolium, porphyrin and its derivatives, and 4,4'-bipyridine.
[0017] Preferably, the molar ratio of the ligand to the functionalization modifier is 1:10-50, the temperature of the second heating is 25℃-300℃, and the heating time is 0.1h-200h.
[0018] Preferably, the metal cation in the second metal salt is at least one of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, rubidium, strontium, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, silver, cadmium, indium, tin, antimony, barium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, gold, mercury, lead, bismuth, lanthanum, cerium, praseodymium, neodymium, platinum, and palladium ions, and the anion includes at least one of halide ions, nitrate ions, acetate ions, or sulfate ions;
[0019] Preferably, the concentration of the metal cation is 10. -5 The concentration is mol / L-1mol / L, and the stirring temperature is 25-300℃ for 0.1h-200h.
[0020] Preferably, the detergent used for washing is at least one of N,N-dimethylformamide, dimethyl sulfoxide, N,N-diethylformamide, N-methylpyrrolidone, methanol, ethanol, water, acetone, dioxane, dichloromethane, ethyl acetate, diethyl ether, and acetone, and the number of washing cycles can be 1-10.
[0021] Preferably, the metal-organic framework is at least one of the following: NU series, UIO-66 series, UIO-67 series, UIO-68 series, MILs series, ZIF series, and PCN series.
[0022] The present invention also provides a functionalized metal-organic framework loaded with metal nanoparticles prepared by the method described above.
[0023] The present invention also provides an application of functionalized metal-organic frameworks loaded with metal nanoparticles in the field of photocatalysis.
[0024] Methods for characterizing the composite structure and catalytic performance of functionalized metal-organic frameworks and metal nanoparticles include SEM (scanning electron microscopy), HAADF-TEM (spherical aberration-high angle annular dark field scanning transmission electron microscopy), TEM (transmission electron microscopy), FTIR (Fourier transform infrared spectroscopy), PXRD (powder X-ray diffraction), photocatalytic hydrogen production testing, and photocatalytic H2O2 production testing, but are not limited to these characterization methods.
[0025] Compared with the prior art, the present invention has the following advantages:
[0026] This invention anchors different functionalization regulators at the metal nodes of metal-organic frameworks (MOFs), utilizing their unique coordination effects to regulate the nucleation and growth processes of metal nanoparticles. This effectively improves their dispersibility and enables controllable size regulation, endowing MOF materials with excellent photocatalytic performance. Furthermore, in terms of synthesis strategies, traditional post-modification methods require replacing the original regulators and are constrained by hard and soft acid-base theories, resulting in significant synthesis difficulties and a limited number of modification sites. This invention employs a direct synthesis method, utilizing functionalization regulators to directly participate in the assembly process of MOFs, significantly improving the synthesis success rate and functional group density. Attached Figure Description
[0027] Figure 1 The image shows the PXRD pattern of the target metal-organic framework in Example 1.
[0028] Figure 2 The image shows the PXRD pattern of the metal-organic framework composite catalytic material loaded with gold nanoparticles in Example 1.
[0029] Figure 3 The image shows the PXRD pattern of the target metal-organic framework and the metal-organic framework composite catalytic material loaded with silver nanoparticles in Example 2.
[0030] Figure 4 The images show the PXRD spectra of the target metal-organic frameworks in Examples 3, 4, and 5.
[0031] Figure 5 The images show the PXRD spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 3, 4, and 5.
[0032] Figure 6 The images show the FTIR spectra of the target metal-organic frameworks in Examples 1, 3, 4, and 5.
[0033] Figure 7 The images show the SEM spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 1, 3, 4, and 5.
[0034] Figure 8 The images show the HAADF-TEM spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 1, 3, 4, and 5.
[0035] Figure 9 The images show the EDS spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 1 and 4.
[0036] Figure 10 The PXRD spectra of the target metal-organic frameworks in Examples 4 and 6 are shown.
[0037] Figure 11The images show the PXRD spectra of the metal-organic framework composite catalytic materials loaded with metal nanoparticles in Examples 4 and 6.
[0038] Figure 12 The images show the PXRD spectra of the target metal-organic frameworks in Examples 7, 8, and 9.
[0039] Figure 13 The PXRD spectra of the metal-organic framework composite catalytic materials loaded with platinum nanoparticles in Examples 7, 8, and 9 are shown.
[0040] Figure 14 The images show the photocatalytic hydrogen evolution performance spectra of the metal-organic framework composite catalytic materials loaded with platinum nanoparticles in Examples 7, 8, and 9.
[0041] Figure 15 The images show the photocatalytic H2O2 production performance spectra of the metal-organic framework composite catalytic materials loaded with platinum nanoparticles in Examples 7, 8, and 9.
[0042] Figure 16 The images show the PXRD spectra of the target metal-organic frameworks in Examples 10, 11, and 12.
[0043] Figure 17 The images show the PXRD spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 10, 11, and 12.
[0044] Figure 18 The image shows the TEM spectrum of the metal-organic framework composite catalytic material loaded with gold nanoparticles in Example 11.
[0045] Figure 19 The image shows the TEM spectrum of the metal-organic framework composite catalytic material loaded with gold nanoparticles in Example 12.
[0046] Figure 20 The images show the photocatalytic hydrogen evolution performance spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 10 and 12.
[0047] Figure 21 The image shows the performance spectrum of the metal-organic framework composite catalytic material loaded with gold nanoparticles in Example 10 for photocatalytic H2O2 production.
[0048] Figure 22 The images show the photocatalytic H2O2 production performance of the metal-organic framework composite catalytic material loaded with gold nanoparticles in Example 11 at different times.
[0049] Figure 23 The images show the PXRD spectra of the target metal-organic frameworks in Examples 7, 13, and 14.
[0050] Figure 24The PXRD spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 7, 13, and 14 are shown.
[0051] Figure 25 The images show the photocatalytic hydrogen evolution performance spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 7, 13, and 14. Detailed Implementation
[0052] To further illustrate the technical solution of the present invention, the present invention will be further described below through embodiments. Under the premise that the embodiments of this application do not conflict with each other, the embodiments and their technical features can be combined arbitrarily. Unless otherwise specified, the experimental methods involved in the following embodiments are conventional methods in the art; the reagents and materials used, unless otherwise specified, can be purchased through commercial channels.
[0053] Example 1
[0054] This embodiment of a method for loading metal nanoparticles onto a functionalized metal-organic framework includes the following steps:
[0055] (1) ZrOCl2·8H2O (97 mg, 0.30 mmol) and benzoic acid (0.7 g, 5.73 mmol) were placed in a pressure-resistant tube, and N,N-dimethylformamide (DMF, 8 mL) was added. The mixture was sonicated for 30 minutes to ensure complete dissolution and mixing. Subsequently, the reaction system was placed in an 80°C drying oven for 60 minutes. After the reaction was completed and cooled to room temperature, ligand 1,3,6,8-tetra(4-carboxyphenyl)pyrene (H4TBAPy, 80 mg, 0.12 mmol) was added, and the mixture was sonicated again for 30 minutes to promote dispersion and dissolution. The reaction system was then transferred to a 100°C drying oven to continue the reaction for 24 hours. After the reaction was completed and cooled to room temperature, the resulting mixture was transferred to a 50 mL centrifuge tube and centrifuged at 11,000 rpm for 5 minutes to collect the precipitate. The precipitate was washed repeatedly with DMF until the supernatant was colorless and transparent, and then washed once with deionized water and once with ethanol. Finally, the obtained solid product was dried in a vacuum drying oven at 60°C for 18 hours to obtain the target metal-organic framework.
[0056] (2) The dried metal-organic framework powder (70 mg) was uniformly dispersed in deionized water (10 mL) and sonicated for 1 hour to obtain a stable and homogeneous metal-organic framework dispersion. The dispersion was then transferred to a 25 mL beaker, and chloroauric acid solution (200 μL, c = 0.25 mol / L) was added. The mixture was stirred in the dark at room temperature for 6 hours to ensure effective loading of the metal precursor. After the reaction, the mixture was centrifuged, washed twice with ethanol, and the resulting solid product was collected. Finally, the washed sample was dried to obtain a metal-organic framework composite catalytic material loaded with metal nanoparticles.
[0057] Figure 1 , Figure 2 The PXRD spectra of the target product obtained in Example 1 and the sample loaded with Au nanoparticles are shown. The diffraction peaks at 5°, 7°, and 10° correspond to the (110), (111), and (211) crystal planes of NU, respectively. These diffraction peak signals are in high agreement with the simulated NU spectrum, indicating that the functional ligand-modified NU was successfully synthesized and its intrinsic crystal structure was maintained. In addition, after loading Au nanoparticles, diffraction peaks at 38° and 44° appeared in the spectrum, which belong to the (111) and (200) crystal planes of Au nanoparticles, respectively, further confirming that Au nanoparticles were successfully loaded onto the metal-organic framework support.
[0058] Example 2
[0059] This embodiment of a method for loading metal nanoparticles onto a functionalized metal-organic framework includes the following steps:
[0060] (1) HfCl4 (96 mg, 0.30 mmol) and p-aminobenzoic acid (0.785 g, 5.73 mmol) were placed in a pressure-resistant tube, and DMF (8 mL) was added. The mixture was sonicated for 30 minutes to ensure complete dissolution and mixing. Subsequently, the reaction system was placed in an 80°C drying oven for 60 minutes. After the reaction was completed and cooled to room temperature, ligand 1,2-aminoterephthalic acid (20 mg, 0.12 mmol) was added, and the mixture was sonicated again for 30 minutes to promote dispersion and dissolution. The reaction system was then transferred to a 100°C drying oven and the reaction continued for 24 hours. After the reaction was completed and cooled to room temperature, the resulting mixture was transferred to a 50 mL centrifuge tube and centrifuged at 11,000 rpm for 5 minutes to collect the precipitate. The precipitate was washed repeatedly with DMF until the supernatant was colorless and transparent, and then washed once with deionized water and once with ethanol. Finally, the obtained solid product was dried in a 60°C vacuum drying oven for 18 hours to obtain the target metal-organic framework.
[0061] (2) The dried metal-organic framework powder (70 mg) was uniformly dispersed in deionized water (10 mL) and sonicated for 1 hour to obtain a stable and homogeneous metal-organic framework dispersion. The dispersion was then transferred to a 25 mL beaker, and silver nitrate solution (2 mL, c = 10 mg / mL) was added. The mixture was stirred at room temperature in the dark for 6 hours to ensure effective loading of the metal precursor. After the reaction, the mixture was centrifuged, washed twice with ethanol, and the resulting solid product was collected. Finally, the washed sample was dried to obtain a metal-organic framework composite catalytic material loaded with metal nanoparticles.
[0062] Figure 3 The PXRD spectra of the target product obtained in Example 2 and the sample loaded with Ag nanoparticles are shown. The diffraction peaks at 7° and 8° correspond to the (111) and (002) crystal planes of UIO-66, respectively. These diffraction peak signals are in high agreement with the simulated UIO-66 spectrum, indicating that the functional ligand modified UIO-66 was successfully synthesized and its intrinsic crystal structure was maintained.
[0063] Example 3
[0064] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with pyrrole-3-carboxylic acid (0.3344 g, 5.73 mmol) added to the reaction solution.
[0065] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as in Example 1.
[0066] Example 4
[0067] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with pyrazole-4-carboxylic acid (0.3374 g, 5.73 mmol) added to the reaction solution.
[0068] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as in Example 1.
[0069] Example 5
[0070] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with 1,2,4-triazol-3-carboxylic acid (0.3403 g, 5.73 mmol) added to the reaction solution.
[0071] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as in Example 1.
[0072] Figure 4The PXRD spectra of the target metal-organic frameworks in Examples 3, 4, and 5 are shown. The diffraction peaks at 5°, 7°, and 10° correspond to the (110), (111), and (211) crystal planes of NU, respectively. These diffraction peak signals are in high agreement with the simulated NU spectra, indicating that the functional ligand-modified NU was successfully synthesized and its intrinsic crystal structure was maintained.
[0073] Figure 5 The PXRD spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 3, 4, and 5 are shown. It is worth noting that no obvious Au diffraction peaks were observed in the Au / NU (2N) sample. The comprehensive characterization of the structure confirms that Au exists in the sample in the form of single atoms.
[0074] Figure 6 The FTIR spectra of the target metal-organic frameworks in Examples 1, 3, 4, and 5 are shown. All samples are at 641 cm⁻¹. -1 721 cm -1 788 cm -1 All peaks at this location exhibit characteristic vibrational peaks belonging to the metal Zr-O cluster. Furthermore, the carboxylic acid groups in the organic linker are clearly observed at 1402 cm⁻¹ in the spectrum. -1 1606 cm -1 The vibration peak at 1552 cm and the vibration peak at 1552 cm -1 1666 cm -1 The vibrational signals of the aromatic CH bonds at the location were observed. These characteristics confirm that NU retains its overall structure even when assembled with different functionalized modifiers. Furthermore, NU(1N), NU(2N), and NU(3N) samples showed vibrations at 1372 cm⁻¹. -1 A distinct NH bond vibrational absorption band was observed at all locations, providing strong evidence for the successful grafting of N-heterocyclic ligands. Furthermore, a slight redshift was observed in the CH vibrational mode, which can be attributed to the influence of the stretching vibrations of adjacent C=N bonds in the ligand.
[0075] Figure 7 The SEM spectra of the target products after loading Au nanoparticles in Examples 1, 3, 4 and 5 are shown. It can be observed from the figures that even when different functionalization modifiers are assembled, the morphological characteristics of each product remain basically consistent, and no obvious structural changes are observed.
[0076] Figure 8 The HAADF-TEM spectra of the corresponding samples, except for Au / NU (2N), clearly showed lattice fringes from Au nanoparticles and NU, and the Au nanoparticles were uniformly dispersed in the carrier.
[0077] Figure 9The EDS spectra of the target products after loading Au nanoparticles in Examples 1 and 4 are further shown. It can be seen that the corresponding elements are uniformly distributed in the system. Combined with the aforementioned characterization results, it shows that Au substances can be uniformly dispersed in the support. This is attributed to the effective anchoring effect of the directly modified functionalization regulator on Au species.
[0078] Example 6
[0079] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the first metal salt is replaced with HfCl4 (55mg, 0.17mmol) and the functionalization regulator is replaced with pyrazole-4-carboxylic acid (0.3374g, 5.73mmol) added to the reaction solution.
[0080] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as in Example 1.
[0081] Figure 10 The PXRD spectra of the target metal-organic frameworks in Examples 4 and 6 are shown. The diffraction peaks at 5°, 7° and 10° correspond to the (110), (111) and (211) crystal planes of NU, respectively. These diffraction peak signals are in high agreement with the simulated NU spectra, indicating that NU assembled with different functionalization modifiers was successfully synthesized and its intrinsic crystal structure was maintained.
[0082] Figure 11 The PXRD spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 4 and 6 are shown. It is worth noting that none of the comparative samples showed the characteristic diffraction peaks of Au, which may be due to the small size of the generated Au nanoparticles or their single-atom morphology.
[0083] Example 7
[0084] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with p-fluorobenzoic acid (0.8031g, 5.73mmol) added to the reaction solution.
[0085] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as in Example 1, except that the second metal salt is replaced with chloroplatinic acid solution (2 mL, c=10 mg / mL) or retained as chloroauric acid solution (200 μL, c=0.25 mol / L) and added to the reaction solution.
[0086] Example 8
[0087] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with 3,4,5-trifluorobenzoic acid (1.0093g, 5.73mmol) added to the reaction solution.
[0088] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as in Example 1, except that the second metal salt is replaced by chloroplatinic acid solution (2 ml, c=10 mg / mL) added to the reaction solution.
[0089] Example 9
[0090] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with 2,3,4,5,6-pentafluorobenzoic acid (1.2256 g, 5.73 mmol) added to the reaction solution.
[0091] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as in Example 1, except that the second metal salt is replaced with chloroplatinic acid solution (2 mL, c=10 mg / mL) added to the reaction solution.
[0092] Figure 12 The PXRD spectra of the target metal-organic frameworks in Examples 7, 8, and 9 are shown. The diffraction peaks at 5°, 7°, and 10° correspond to the (110), (111), and (211) crystal planes of NU, respectively. These diffraction peak signals are in high agreement with the simulated NU spectra, indicating that NU assembled with different functionalization modifiers was successfully synthesized and its intrinsic crystal structure was maintained.
[0093] Figure 13 The PXRD spectra of the metal-organic framework composite catalytic materials loaded with platinum nanoparticles in Examples 7, 8, and 9 are shown. It is worth noting that none of the comparative samples showed characteristic diffraction peaks of Pt, which may be due to the small size of the generated Pt nanoparticles or their single-atom morphology.
[0094] Figure 14 The photocatalytic hydrogen evolution performance of the target products obtained after loading Pt nanoparticles in Examples 7, 8, and 9 is shown. It can be observed that Pt / NU (1F), Pt / NU (3F), and Pt / NU (5F) all exhibit high hydrogen evolution rates. This phenomenon is attributed to the effective anchoring of Pt single atoms by the functionalization regulator, which increases the number of active sites, improves the atom utilization rate, and thus enhances the photocatalytic hydrogen evolution performance.
[0095] Figure 15 The performance graphs of photocatalytic H2O2 production of the corresponding samples are shown, and the concentration of H2O2 was determined by potassium titanium oxalate spectrophotometry.
[0096] Example 10
[0097] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with p-thiol benzoic acid (0.8838g, 5.7mmol) added to the reaction solution.
[0098] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as in Example 1.
[0099] Example 11
[0100] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with 4-ethynylbenzoic acid (0.8477 g, 5.73 mmol) added to the reaction solution.
[0101] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as that in Example 1, except that the light-shielding time is replaced with 0.5h, 1h and 2h respectively.
[0102] Example 12
[0103] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with p-hydroxybenzoic acid (0.7917 g, 5.7 mmol) added to the reaction solution.
[0104] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as in Example 1.
[0105] Figure 16 The PXRD spectra of the target metal-organic frameworks in Examples 10, 11, and 12 are shown. The diffraction peaks at 5°, 7°, and 10° correspond to the (110), (111), and (211) crystal planes of NU, respectively. These diffraction peak signals are in high agreement with the simulated NU spectra, indicating that NU assembled with different functionalization modifiers was successfully synthesized and its intrinsic crystal structure was maintained.
[0106] Figure 17 The PXRD spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 10, 11, and 12 are shown. It is worth noting that diffraction peaks at 38° and 44° appear in the spectra, which belong to the (111) and (200) crystal planes of the Au species, respectively, further confirming that Au nanoparticles have been successfully loaded onto the metal-organic framework support.
[0107] Figure 18 and Figure 19The images show the TEM spectra of the target products obtained after loading Au nanoparticles in Examples 11 and 12, respectively. The images reveal that the Au nanoparticles are relatively uniform in size and exhibit good dispersion on the support. This result further confirms the feasibility of the strategy of effectively anchoring and stabilizing metal nanoparticles by directly assembling functionalization modifiers.
[0108] Figure 20 The photocatalytic hydrogen evolution performance spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 10 and 12 are shown. Due to the effective anchoring of Au species by the functional groups -SH and -OH, they exhibit hydrogen evolution performance of 0.462 and 0.405 mmol g, respectively. -1 h -1 The hydrogen evolution rate.
[0109] Figure 21 The performance spectrum of the metal-organic framework composite catalytic material loaded with gold nanoparticles in Example 10 for photocatalytic H2O2 production is shown. Due to the controllable preparation of Au species size, it ultimately exhibits a yield of 0.9 mmol g. -1 h -1 Its excellent performance.
[0110] Figure 22 The performance spectra of the photocatalytic H2O2 production of the metal-organic framework composite catalytic material loaded with gold nanoparticles in Example 11 at different loading times are shown. By optimizing the reduction time of Au ions, the sample reduced for 1 hour showed the best H2O2 production performance, at 1.2 mmol g. -1 h -1 .
[0111] Experimental Example 13
[0112] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with p-chlorobenzoic acid (0.8975g, 5.73mmol) added to the reaction solution.
[0113] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as that in Example 1, except that the light-shielding time is replaced with 2 min.
[0114] Example 14
[0115] (1) The preparation method of the target metal-organic framework is the same as in Example 1, except that the functionalization regulator is replaced with p-bromobenzoic acid (1.1523g, 5.73mmol) added to the reaction solution.
[0116] (2) The preparation method of the metal-organic framework composite catalytic material loaded with metal nanoparticles is the same as in Example 1, except that the light-shielding time is replaced with 10 min.
[0117] Figure 23 The PXRD spectra of the target metal-organic frameworks in Examples 7, 13, and 14 are shown. The diffraction peaks at 5°, 7°, and 10° correspond to the (110), (111), and (211) crystal planes of NU, respectively. These diffraction peak signals are in high agreement with the simulated NU spectra, indicating that NU assembled with different functionalization modifiers was successfully synthesized and its intrinsic crystal structure was maintained.
[0118] Figure 24 The PXRD spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 7, 13, and 14 are shown. It is worth noting that diffraction peaks at 38° and 44° appear in the spectra, which belong to the (111) and (200) crystal planes of the Au species, respectively, further confirming that Au nanoparticles have been successfully loaded onto the metal-organic framework support.
[0119] Figure 25 The photocatalytic hydrogen evolution performance spectra of the metal-organic framework composite catalytic materials loaded with gold nanoparticles in Examples 7, 13, and 14 are shown. Due to the different degrees of anchoring of Au species by different functionalization modifiers, different hydrogen evolution performances were ultimately exhibited. Among them, Au / NU(Br) showed the highest hydrogen evolution rate, which was 0.238 mmol g. -1 h -1 .
[0120] The foregoing has shown and described the main features and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.
[0121] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A method for loading metal nanoparticles onto a functionalized metal-organic framework, characterized in that, Includes the following steps: Step 1: Mix the first metal salt, functionalization modifier, and solvent evenly, and heat for the first time to obtain the first solution. Step 2: Mix the first solution with the ligand to obtain the second solution, and then heat it a second time to obtain a functionalized metal-organic framework. Step 3: Mix the functionalized metal-organic framework with the solvent until homogeneous, then mix with the second metal salt to obtain the third solution. After stirring, controllable loading of metal nanoparticles on the metal-organic framework is achieved. The functional group modifier includes at least one of benzoic acid, isonicotinic acid, pyrrole-3-carboxylic acid, pyrazole-4-carboxylic acid, 1,2,4-triazole-3-carboxylic acid, p-fluorobenzoic acid, p-chlorobenzoic acid, p-bromobenzoic acid, p-hydroxybenzoic acid, p-aminobenzoic acid, p-mercaptobenzoic acid, 3-thiophenecarboxylic acid, 3-furanocarboxylic acid, 3-pyrrolecarboxylic acid, 4-ethynylbenzoic acid, 3,5-difluorobenzoic acid, 1H-benzimidazole-5-carboxylic acid, 3,4,5-trifluorobenzoic acid, 2,3,4,5,6-pentafluorobenzoic acid, and p-cyanobenzoic acid.
2. The method for loading metal nanoparticles onto a functionalized metal-organic framework according to claim 1, characterized in that, The metal cation in the first metal salt is at least one of Zr, Hf, Ti, Co, Ni, Fe, Zn, Cu, Mg, Cd, Cr, Ce, Al, and Ca ions, and the anion is at least one of halide ions, nitrate ions, acetate ions, or sulfate ions.
3. The method for loading metal nanoparticles onto a functionalized metal-organic framework according to claim 1, characterized in that, The solvent is at least one selected from N,N-dimethylformamide, dimethyl sulfoxide, N,N-diethylformamide, N-methylpyrrolidone, methanol, ethanol, water, acetone, dioxane, dichloromethane, ethyl acetate, diethyl ether, and acetone.
4. The method for loading metal nanoparticles onto a functionalized metal-organic framework according to claim 1, characterized in that, The molar ratio of the first metal salt to the functionalization modifier is 1:10-50, and the temperature of the first heating is 25℃-300℃, and the time is 0.1h-200h.
5. The method for loading metal nanoparticles onto a functionalized metal-organic framework according to claim 1, characterized in that, The ligand is at least one of 1,3,6,8-tetra(4-carboxyphenyl)pyrene, 1,3,5-tricarboxyphenylbenzene, 4,4',4'',4'''-(peryl-2,5,8,11-tetrayl)tetrabenzoic acid, neu-tetra(4-carboxyphenyl)porphyrin, 4,4',4'',4'''-(dibenzo[g, p]benzophenanthrene-2,7,10,15-tetrayl)tetrabenzoic acid, tetra[4-(4'-carboxyphenyl)phenyl]ethylene, 1,4-phthalic acid, 2-aminoterephthalic acid, 2-nitroterephthalic acid, biphenyl-4,4'-dicarboxylic acid, p-triphenyl-4,4'-dicarboxylic acid, pyromellitic acid, fumaric acid, 2-methylimidazolium, porphyrin and its derivatives, and 4,4'-bipyridine.
6. The method for loading metal nanoparticles onto a functionalized metal-organic framework according to claim 1, characterized in that, The molar ratio of the ligand to the functionalization modifier is 1:10-50, the second heating temperature is 25℃-300℃, and the heating time is 0.1h-200h.
7. The method for loading metal nanoparticles onto a functionalized metal-organic framework according to claim 1, characterized in that, The metal cation in the second metal salt is at least one of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, rubidium, strontium, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, silver, cadmium, indium, tin, antimony, barium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, gold, mercury, lead, bismuth, lanthanum, cerium, praseodymium, neodymium, platinum, and palladium ions, and the anion includes at least one of halide ions, nitrate ions, acetate ions, or sulfate ions; The concentration of the metal cation is 10. -5 The concentration is mol / L-1mol / L, and the stirring temperature is 25-300℃ for 0.1h-200h.
8. The method for loading metal nanoparticles onto a functionalized metal-organic framework according to claim 1, characterized in that, The metal-organic framework is at least one of the following: NU series, UIO-66 series, UIO-67 series, UIO-68 series, MILs series, ZIF series, and PCN series.
9. Functionalized metal-organic frameworks loaded with metal nanoparticles prepared by the method of any one of claims 1-8.
10. The application of the functionalized metal-organic framework loaded with metal nanoparticles as described in claim 9 in the field of photocatalysis.