Titanium-cerium-based metal organic framework material as well as preparation method and application thereof
By preparing titanium-cerium-based metal organic frame materials as catalysts, the problems of insufficient activity and stability of existing catalysts in catalytic degradation of VOCs are solved, and the efficient toluene degradation effect is achieved, which is suitable for industrial applications.
Patent Information
- Application Number
- CN202510431425.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-08
- Publication Date
- 2025-07-11
AI Technical Summary
When existing catalysts catalytically degrade volatile organic compounds (VOCs), they have insufficient number of active sites and adsorption capacity, and are prone to aggregation and poisoning during the reaction, resulting in low degradation activity, limiting their practical application.
Using titanium-cerium-based metal organic frame material as catalyst, the node is Ti-Ce oxygen cluster and the ligand is porphyrin tetrabenoline. Materials with porous structure and high thermal stability are prepared by specific synthetic methods for catalytic degradation of VOCs.
It achieves high reactivity and excellent thermal catalytic degradation performance, especially the complete degradation of toluene, which is suitable for large-scale industrial applications.
Smart Images
Figure CN120289809A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of porous materials, and particularly relates to a titanium-cerium-based metal-organic framework material, a preparation method thereof, and an application thereof. Background Art
[0002] Volatile organic compounds (VOCs) such as benzene, toluene, and xylene not only cause ecological environmental pollution, but also cause irreversible harm to human health. At present, VOCs are mainly removed by catalytic degradation, and the catalysts used mainly include carbon-based materials such as activated carbon, biochar, and activated carbon fibers, as well as oxygen-containing materials such as zeolites, clays, and silica gels. However, these catalysts are limited by the number of active sites and adsorption capacity, and can only exhibit low degradation activity. Moreover, these catalysts are prone to aggregation and poisoning during the catalytic reaction process, and their practical applications are greatly limited.
[0003] Therefore, it is of great significance to develop a catalyst with high reaction activity, excellent performance in catalytic degradation of VOCs, and high stability. Summary of the Invention
[0004] The purpose of the present invention is to provide a titanium-cerium-based metal-organic framework material, a preparation method thereof, and an application thereof.
[0005] The technical solution adopted by the present invention is as follows:
[0006] A titanium-cerium-based metal-organic framework material, the node of which is a Ti-Ce oxygen cluster, and the ligand is tetra(4-carboxyphenyl)porphyrin; the chemical formula of the Ti-Ce oxygen cluster is Ti9Ce4(BA) 20 , where BA is benzoic acid.
[0007] Preferably, the Ti-Ce oxygen cluster has a D 4h symmetric structure (specifically, a D 4h symmetric structure assembled by 16 μ2-carboxyl groups, 4 μ2-O and 8 μ3-O of benzoic acid with Ce(IV) and Ti(IV)).
[0008] Preferably, the Ti-Ce oxygen cluster has undergone partial hydrolysis. After partial hydrolysis of the Ti-Ce oxygen cluster, Ce(IV) and Ti(IV) of the metal center can still be retained, and it will not affect its coordination with tetra(4-carboxyphenyl)porphyrin to form a titanium-cerium-based metal-organic framework material.
[0009] A preparation method of a titanium-cerium-based metal-organic framework material as described above includes the following steps:
[0010] 1) Dispersing a titanium source, a cerium source, and benzoic acid in an organic solvent for reaction, and then separating the product to obtain a Ti-Ce oxygen cluster;
[0011] 2) Disperse Ti-Ce oxygen cluster, tetra(4-carboxyphenyl)porphyrin, and organic acid in an organic solvent for reaction, and then perform product separation to obtain the titanium-cerium-based metal-organic framework material.
[0012] Preferably, the molar ratio of the titanium source, cerium source, and benzoic acid in step 1) is 1:0.5 - 1.5:6 - 12.
[0013] Preferably, the titanium source in step 1) is at least one of titanium tetraisopropoxide, titanium tetrabutoxide, titanium acetylacetonate, and titanium tetrachloride.
[0014] Preferably, the cerium source in step 1) is at least one of cerium nitrate, cerium chloride, cerium acetate, and cerium citrate.
[0015] Preferably, the organic solvent in step 1) is at least one of acetonitrile, methanol, ethanol, and isopropanol.
[0016] Preferably, the reaction in step 1) is carried out at a temperature of 60°C - 100°C for a reaction time of 20 h - 30 h.
[0017] Preferably, the mass ratio of the Ti-Ce oxygen cluster to tetra(4-carboxyphenyl)porphyrin (TCPP) in step 2) is 1 - 3.5:1.
[0018] Preferably, the organic acid in step 2) is at least one of benzoic acid, o-fluorobenzoic acid, m-fluorobenzoic acid, trifluoroacetic acid, and difluoroacetic acid.
[0019] Preferably, the organic solvent in step 2) is at least one of N,N-dimethylformamide (DMF) and N,N-diethylformamide (DEF).
[0020] Preferably, the reaction in step 2) is carried out at a temperature of 100°C - 160°C for a reaction time of 12 h - 24 h.
[0021] Application of the titanium-cerium-based metal-organic framework material as described above for degrading benzene, toluene, or xylene.
[0022] A method for thermally catalytically degrading toluene includes the following steps: Place the above-mentioned titanium-cerium-based metal-organic framework material in a reaction tube, and then introduce toluene vapor for reaction.
[0023] Preferably, the concentration of the toluene vapor is 100 ppm - 1000 ppm.
[0024] Preferably, the reaction is carried out at a temperature of 180°C - 300°C.
[0025] The beneficial effects of the present invention are as follows: The titanium-cerium-based metal-organic framework material of the present invention has high reaction activity, excellent performance in thermal catalytic degradation of toluene, high thermal stability, etc., and can be used for the catalytic degradation of VOCs such as benzene, toluene, and xylene, and is suitable for large-scale industrial applications.
[0026] Specifically:
[0027] The titanium-cerium-based metal-organic framework material of the present invention has a porous structure, a large specific surface area, and high thermal stability. It has an excellent adsorption effect on toluene. Ce(IV), Ce(III), and Ti(IV) in the Ti-Ce oxygen cluster at the node can serve as excellent reaction sites for toluene degradation, improving the efficiency of thermal catalytic toluene degradation (the toluene conversion rate can reach 100% at 280 °C), and can be used for the catalytic degradation of VOCs such as benzene, toluene, and xylene, and is suitable for large-scale industrial applications. Description of the Drawings
[0028] Figure 1 XRD patterns of the Ti-Ce oxygen cluster and the titanium-cerium-based metal-organic framework material in Example 1.
[0029] Figure 2 TG curve of the titanium-cerium-based metal-organic framework material in Example 1.
[0030] Figure 3 SEM images of the Ti-Ce oxygen cluster and the titanium-cerium-based metal-organic framework material in Example 1.
[0031] Figure 4 SEM image of the Ti-Ce oxygen cluster in Comparative Example 1.
[0032] Figure 5 Catalytic performance test result graphs of the titanium-cerium-based metal-organic framework materials in Examples 1-3 and Comparative Examples 1-2. Detailed Embodiments
[0033] The present invention will be further explained and described below in conjunction with specific embodiments.
[0034] Example 1:
[0035] A titanium-cerium-based metal-organic framework material, and its preparation method is as follows:
[0036] 1) Dissolve 5 g (0.041 mol) of benzoic acid in 60 mL of acetonitrile, then add 1 mL (0.0034 mol) of tetra-isopropyl titanate and 1 g (0.0031 mol) of cerium nitrate, and then raise the temperature to 60 °C and react for 24 h. Filter, take the solid and dry it at 70 °C to obtain the Ti-Ce oxygen cluster (denoted as Ti9Ce4(BA) 20 )
[0037] 2) Disperse 0.1 g of Ti-Ce oxygen cluster, 0.06 g of tetra(4-carboxyphenyl)porphyrin, 2 g of benzoic acid and 100 μL of trifluoroacetic acid in 20 mL of N,N-dimethylformamide, then heat to 120 °C and react for 24 h. Filter and place the solid obtained at 70 °C for drying to obtain the titanium-cerium-based metal-organic framework material (denoted as Ti / Ce-TCPP-MOF).
[0038] Performance test:
[0039] 1) The X-ray diffraction (XRD) patterns of the Ti-Ce oxygen cluster (Ti9Ce4(BA) 20 ) and the titanium-cerium-based metal-organic framework material (Ti / Ce-TCPP-MOF) in this example are as Figure 1 shown.
[0040] It can be seen from Figure 1 that both Ti9Ce4(BA) 20 and Ti / Ce-TCPP-MOF have good crystallinity.
[0041] 2) The thermogravimetric (TG) curve of the titanium-cerium-based metal-organic framework material (Ti / Ce-TCPP-MOF) in this example is as Figure 2 shown.
[0042] It can be seen from Figure 2 that Ti / Ce-TCPP-MOF can still maintain a stable MOF framework at 385 °C, indicating its high thermal stability.
[0043] 3) The scanning electron microscope (SEM) images of the Ti-Ce oxygen cluster (Ti9Ce4(BA) 20 ) and the titanium-cerium-based metal-organic framework material (Ti / Ce-TCPP-MOF) in this example are as Figure 3 (a is Ti9Ce4(BA) 20 , b is Ti / Ce-TCPP-MOF) shown.
[0044] It can be seen from Figure 3 that Ti9Ce4(BA) 20 shows a cluster morphology with relatively large size, and Ti / Ce-TCPP-MOF maintains a stable MOF framework.
[0045] Example 2:
[0046] A titanium-cerium-based metal-organic framework material, and its preparation method is as follows:
[0047] Disperse 0.1 g of Ti-Ce oxygen cluster (same as in Example 1), 0.04 g of tetra(4-carboxyphenyl)porphyrin, and 2.4 g of benzoic acid in 20 mL of N,N-dimethylformamide, then raise the temperature to 120 °C and react for 24 h. Filter, and place the solid obtained at 70 °C for drying to obtain a titanium-cerium-based metal-organic framework material (denoted as Ti / Ce-TCPP-MOF).
[0048] Tested (same as in Example 1), the Ti / Ce-TCPP-MOF in this example also has good crystallinity and high thermal stability, and its microscopic morphology is basically the same as that of the Ti / Ce-TCPP-MOF in Example 1.
[0049] Example 3:
[0050] A titanium-cerium-based metal-organic framework material, and its preparation method is as follows:
[0051] Disperse 0.1 g of Ti-Ce oxygen cluster (same as in Example 1), 0.1 g of tetra(4-carboxyphenyl)porphyrin, 2.6 g of benzoic acid, and 100 μL of trifluoroacetic acid in 20 mL of N,N-dimethylformamide, then raise the temperature to 120 °C and react for 24 h. Filter, and place the solid obtained at 70 °C for drying to obtain a titanium-cerium-based metal-organic framework material (denoted as Ti / Ce-TCPP-MOF).
[0052] Tested (same as in Example 1), the Ti / Ce-TCPP-MOF in this example also has good crystallinity and high thermal stability, and its microscopic morphology is basically the same as that of the Ti / Ce-TCPP-MOF in Example 1.
[0053] Comparative Example 1:
[0054] A titanium-cerium-based metal-organic framework material, and its preparation method is as follows:
[0055] 1) Dissolve 5 g of benzoic acid in 60 mL of acetonitrile, then add 1 mL of titanium tetraisopropoxide and 1 g of cerium nitrate, and react at room temperature for 36 h. Filter, and place the solid obtained at 70 °C for drying to obtain a Ti-Ce oxygen cluster (denoted as Ti8Ce2(BA) 16 )
[0056] 2) Disperse 0.1 g of Ti-Ce oxygen cluster, 0.06 g of tetra(4-carboxyphenyl)porphyrin, 2 g of benzoic acid, and 100 μL of trifluoroacetic acid in 20 mL of N,N-dimethylformamide, then raise the temperature to 120 °C and react for 24 h. Filter, and place the solid obtained at 70 °C for drying to obtain a titanium-cerium-based metal-organic framework material (denoted as Ti8Ce2-TCPP-MOF).
[0057] The SEM image of the Ti-Ce oxygen cluster (Ti8Ce2(BA) 16 ) in this comparative example is as Figure 4 shown.
[0058] It can be seen from Figure 4 that: Ti8Ce2(BA) 16 also shows a cluster morphology with relatively large size, but there are significant differences in shape compared with Ti9Ce4(BA) 20 .
[0059] Comparative Example 2:
[0060] A titanium-cerium-based metal-organic framework material, and its preparation method is as follows:
[0061] Disperse 0.1 g of Ti-Ce oxygen cluster (the same as in Example 1), 0.06 g of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene (TBAPY), 2 g of benzoic acid and 100 μL of trifluoroacetic acid in 20 mL of N,N-dimethylformamide, then raise the temperature to 120 °C and react for 24 h, filter, and place the solid obtained at 70 °C for drying to obtain the titanium-cerium-based metal-organic framework material (denoted as Ti / Ce-TBAPY-MOF).
[0062] Catalytic performance test:
[0063] Place 40 mg of the titanium-cerium-based metal-organic framework materials in Examples 1 to 3 and Comparative Examples 1 to 2 into a quartz reaction tube, then introduce toluene vapor with a concentration of 400 ppm, and then carry out the reaction under the condition of a temperature of 190 °C to 300 °C, detect the concentrations of CO2 and toluene, calculate the toluene conversion rate, and the catalytic performance test results of the obtained titanium-cerium-based metal-organic framework materials are as Figure 5 shown.
[0064] The calculation formula for toluene conversion rate is as follows: Toluene conversion rate (%) = (molar amount of toluene introduced - molar amount of toluene discharged) / molar amount of toluene introduced × 100%.
[0065] It can be seen from Figure 5 that:
[0066] a) The titanium-cerium-based metal-organic framework material (Ti8Ce2-TCPP-MOF) in Comparative Example 1 only has toluene degradation activity at 220 °C, and the toluene conversion rate is only 29% at 300 °C;
[0067] b) The titanium-cerium-based metal-organic framework material (Ti / Ce-TBAPY-MOF) in Comparative Example 2 does not have toluene degradation activity below 210 °C, and the toluene conversion rate is only 40% at 300 °C;
[0068] c) The titanium-cerium-based metal-organic framework material in Example 1 has toluene degradation activity at 190 °C, and complete degradation of toluene can be achieved at 280 °C. The toluene conversion rate remains stable at 280 °C, 290 °C, and 300 °C.
[0069] d) The toluene conversion rates of the titanium-cerium-based metal-organic framework materials in Example 2 and Example 3 are close to 100% at 300 °C.
[0070] In summary, regulating the acid-base conditions is beneficial to promoting the synthesis of Ti / Ce-TCPP-MOF. At the same time, the interaction between the unique Ti9Ce4 nodes and the porphyrin ligands endows Ti / Ce-TCPP-MOF with outstanding advantages in the thermal catalytic degradation of toluene, making it suitable for the catalytic degradation of VOCs such as benzene, toluene, and xylene.
[0071] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.
Claims
1. A titanium-cerium-based metal-organic framework material, characterized in that, The node is a Ti-Ce oxygen cluster and the ligand is four pairs of benzoic acid porphyrin; the chemical formula of the Ti-Ce oxygen cluster is Ti9Ce4(BA) 20 , where BA is benzoic acid.
2. The titanium-cerium-based metal-organic framework material according to claim 1, characterized in that: The Ti-Ce oxygen cluster is in a D 4h symmetrical structure.
3. The titanium-cerium-based metal-organic framework material according to claim 1 or 2, characterized in that: Partial hydrolysis of the Ti-Ce oxygen cluster occurred.
4. A method for preparing a titanium-cerium-based metal-organic framework material according to any one of claims 1 to 3, characterized in that, It includes the following steps: 1) React a titanium source, a cerium source, and benzoic acid by dispersing them in an organic solvent, and then separate the product to obtain a Ti-Ce oxygen cluster; 2) React the Ti-Ce oxygen cluster, tetra(4-carboxyphenyl)porphyrin, and an organic acid by dispersing them in an organic solvent, and then separate the product to obtain the titanium-cerium-based metal-organic framework material.
5. The preparation method according to claim 4, characterized in that: In step 1), the molar ratio of the titanium source, the cerium source, and benzoic acid is 1:0.5-1.5:6-12; the titanium source in step 1) is at least one of titanium tetraisopropoxide, titanium tetrabutoxide, titanium acetylacetonate, and titanium tetrachloride; the cerium source in step 1) is at least one of cerium nitrate, cerium chloride, cerium acetate, and cerium citrate.
6. The preparation method according to claim 4 or 5, characterized in that: The reaction in step 1) is carried out at a temperature of 60°C-100°C for a reaction time of 20h-30h.
7. The preparation method according to claim 4, characterized in that: In step 2), the mass ratio of the Ti-Ce oxygen cluster to tetra(4-carboxyphenyl)porphyrin is 1-3.5:1; the organic acid in step 2) is at least one of benzoic acid, o-fluorobenzoic acid, m-fluorobenzoic acid, trifluoroacetic acid, and difluoroacetic acid.
8. The preparation method according to claim 4 or 7, characterized in that: The reaction in step 2) is carried out at a temperature of 100°C-160°C for a reaction time of 12h-24h.
9. Application of the titanium-cerium-based metal-organic framework material according to any one of claims 1-3 in degrading benzene, toluene, or xylene.
10. A method for catalytic thermal degradation of toluene, characterized in that, It includes the following steps: Place the titanium-cerium-based metal-organic framework material according to any one of claims 1-3 in a reaction tube, and then introduce toluene vapor for reaction.