Metal-doped zirconium-based MOF loaded noble metal catalyst as well as preparation method and application thereof
By doping metals into zirconium-based MOF and introducing precious metals, the problem of degradation of existing catalysts in high temperature and oxidation environments is solved, and efficient VOCs catalytic combustion is achieved, especially in catalytic oxidation of toluene.
Patent Information
- Application Number
- CN202411536017.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-02-11
AI Technical Summary
Existing zirconium-based precious metal catalysts are prone to sintering and agglomeration under high temperature and oxidation environments, resulting in reduced catalytic performance and higher cost.
The noble metal catalyst is loaded with metal doped zirconium-based MOF, and the dispersion of precious metals is improved by doping metals such as Mn, Ce, Co or Cu in the zirconium-based MOF, and introducing precious metals Ru, Pd or Pt.
The noble metal dispersion of the catalyst is significantly improved, and the catalytic combustion activity of parabenzene VOCs is enhanced, especially the catalytic oxidation performance of para-toluene is excellent under low temperature conditions.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of catalysts, and in particular to a metal-doped zirconium-based MOF-loaded noble metal catalyst and a preparation method and application thereof. Background Art
[0002] Volatile organic compounds are the main factors in the production of ozone and fine particulate matter, causing serious harm to human health and the ecological environment. Toluene, as one of the representatives of VOCs, causes serious harm to human health, such as poisoning of the nervous system and lungs. Compared with transition metal oxide catalysts, supported noble metal catalysts have higher catalytic activity for low-temperature catalytic degradation of VOCs. In particular, supported palladium catalysts have high catalytic activity for aromatic hydrocarbon pollutants, and therefore have been widely studied in the elimination of VOCs.
[0003] MOFs are an excellent carrier for supporting metal nanocatalysts. Compared with other MOFs, they have high chemical stability. Highly dispersed supported precious metal nanocrystals are necessary for many industrially important catalytic reactions. However, under actual working conditions, especially under high temperature and oxidative environments, the smaller the nanoparticles, the easier it is to sinter and agglomerate, resulting in reduced catalytic performance. Summary of the invention
[0004] In view of the above-mentioned deficiencies in the prior art, the present invention aims to provide a metal-doped zirconium-based MOF-supported noble metal catalyst and its preparation method and application, and to develop a catalyst with high catalytic activity for catalytic combustion of benzene VOCs while reducing the cost of combustion catalysts.
[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:
[0006] In the first aspect, a metal-doped zirconium-based MOF-loaded precious metal catalyst is provided, which is prepared using a metal-doped zirconium-based MOF as a precursor and has a structural formula of MN-Zr, wherein M is a precious metal Ru, Pd or Pt, and the mass percentage of the precious metal is 0.01% to 10%, and N is a doped metal Mn, Ce, Co or Cu, and the molar percentage of the doped metal is 10% to 30%.
[0007] In a second aspect, a method for preparing a metal-doped zirconium-based MOF-supported noble metal catalyst is provided, which comprises the following steps:
[0008] (1) 1,3,5-benzenetricarboxylic acid H 3 BTC, ZrClO 2 8H 2O and metal N precursors are dissolved in DMF / formic acid and stirred until completely dissolved. The mixture is rapidly heated to 100-130°C using a reflux condensation method and maintained for 12-48 hours. The white precipitate is obtained by centrifugation, and the precipitate is washed with DMF and then shaken for 10-15 minutes. This operation is repeated several times, and the mixture is dynamically dried in vacuum overnight. After drying, the white powder N-Zr-MOF is obtained by grinding.
[0009] (2) Dissolve the M solution in deionized water, add N-Zr-MOF powder to the solution, stir at room temperature, centrifuge, dynamically dry overnight at 80-130°C in vacuum, and grind to obtain powder after drying; calcine the powder at 750°C for 2-6h to obtain MN-Zr, where M is a precious metal Ru, Pd or Pt, and N is a doped metal Mn, Ce, Co or Cu.
[0010] The third aspect provides the application of metal-doped zirconium-based MOF-loaded precious metal catalysts in the catalytic removal of VOCs gases.
[0011] Furthermore, it is used for catalytic removal of toluene VOCs gas, and the specific process is: using air as an oxidant for combustion reaction, and the reaction temperature is 100-700°C.
[0012] The beneficial effects of the present invention are:
[0013] The present invention dopes a metal organic framework with metal and introduces a noble metal, which greatly improves the dispersion of the noble metal compared to the zirconium-based noble metal catalyst prepared by the traditional method. The catalyst has high VOCs catalytic combustion activity, especially its excellent catalytic oxidation performance of toluene, and has broad application prospects in the field of catalytic oxidation of organic waste gas. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 XRD diagram of the catalysts prepared in Examples 1-7;
[0015] Figure 2 Schematic diagram of the toluene catalytic combustion activity of the catalysts prepared in Examples 1-5;
[0016] Figure 3 This is a schematic diagram of the toluene catalytic combustion activity of the catalysts prepared in Example 1, Example 6, and Example 7;
[0017] Figure 4 The SEM images of the catalysts prepared in Example 1 are: (a) Mn-Zr, (b) Pd-Mn-Zr.
[0018] Figure 5 EDS surface scans of the catalysts prepared in Example 1 and Example 5; (a) Pd-Mn-Zr, (b) Pd-Zr. DETAILED DESCRIPTION
[0019] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.
[0020] Example 1
[0021] (1) 1,3,5-benzenetricarboxylic acid H 3 BTC(2.52g), ZrClO 2 8H 2 O(9.86g) and 50%Mn(NO 3 ) 2 (1.93 g) was dissolved in a flask containing DMF / formic acid (300 mL / 300 mL), stirred for 1 h until completely dissolved, and then rapidly heated to 130 ° C using the reflux condensation method and maintained for 48 h. A white precipitate was obtained by centrifugation (8000 r / min, 5 min), which was washed with DMF and then shaken for 10-15 min. This operation was repeated 3 times, and then dynamically dried at 80 ° C overnight in a vacuum, and then ground to obtain white powder Mn-Zr-MOF.
[0022] (2) Take 0.1 ml of 54 mg Pd / ml palladium nitrate solution and dissolve it in 150 ml of deionized water, add 2 g of Mn-Zr-MOF powder to the solution, stir at room temperature for 1 hour, centrifuge (8000 r / min, 5 min), wash with water for the last time, dynamically dry at 80°C in vacuum overnight, grind to obtain powder after drying. The powder is calcined at 750°C at 2.5°C / min for 3 hours to obtain Pd-Mn-Zr catalyst material.
[0023] Example 2
[0024] (1) 1,3,5-benzenetricarboxylic acid H 3 BTC(2.52g), ZrClO 2 8H 2 O(9.86g) and Ce(NO 3 ) 3 6H 2O (2.35 g) was dissolved in a flask containing DMF / formic acid (300 mL / 300 mL), stirred for 1 h until completely dissolved, and then rapidly heated to 130 ° C using the reflux condensation method and maintained for 48 h. A white precipitate was obtained by centrifugation (8000 r / min, 5 min), which was washed with DMF and then shaken for 10-15 min. This operation was repeated 3 times, and then dynamically dried at 80 ° C overnight in a vacuum, and then ground to obtain white powder Ce-Zr-MOF.
[0025] (2) Take 0.1 ml of 54 mg Pd / ml palladium nitrate solution and dissolve it in 150 ml of deionized water, add 2 g of Ce-Zr-MOF powder to the solution, stir at room temperature for 1 hour, centrifuge (8000 r / min, 5 min), wash with water for the last time, dynamically dry at 80°C in vacuum overnight, grind to obtain powder after drying. The powder is calcined at 750°C at 2.5°C / min for 3 hours to obtain Pd-Ce-Zr catalyst material.
[0026] Example 3
[0027] (1) 1,3,5-benzenetricarboxylic acid H 3 BTC(2.52g), ZrClO 2 8H 2 O(9.86g) and Co(NO 3 ) 2 6H 2 O (1.57 g) was dissolved in a flask containing DMF / formic acid (300 mL / 300 mL), stirred for 1 h until completely dissolved, and then rapidly heated to 130 ° C using the reflux condensation method and maintained for 48 h. A white precipitate was obtained by centrifugation (8000 r / min, 5 min), which was washed with DMF and then shaken for 10-15 min. This operation was repeated 3 times, and dynamically dried at 80 ° C overnight in a vacuum, and then ground to obtain white powder Co-Zr-MOF.
[0028] (2) Take 0.1 ml of 54 mg Pd / ml palladium nitrate solution and dissolve it in 150 ml of deionized water, add 2 g of Co-Zr-MOF powder to the solution, stir at room temperature for 1 hour, centrifuge (8000 r / min, 5 min), wash with water for the last time, dynamically dry at 80°C in vacuum overnight, grind to obtain powder after drying. The powder is calcined at 750°C at 2.5°C / min for 3 hours to obtain Pd-Co-Zr catalyst material.
[0029] Example 4
[0030] (1) 1,3,5-benzenetricarboxylic acid H 3 BTC(2.52g), ZrClO 2 8H2 O(9.86g) and Cu(NO 3 ) 2 ·3H 2 O (1.31 g) was dissolved in a flask containing DMF / formic acid (300 mL / 300 mL), stirred for 1 h until completely dissolved, and then rapidly heated to 130 ° C using the reflux condensation method and maintained for 48 h. A white precipitate was obtained by centrifugation (8000 r / min, 5 min), which was washed with DMF and then shaken for 10-15 min. This operation was repeated 3 times, and dynamically dried at 80 ° C overnight in a vacuum, and then ground to obtain a white powder Cu-Zr-MOF.
[0031] (2) Take 0.1 ml of 54 mg Pd / ml palladium nitrate solution and dissolve it in 150 ml of deionized water, add 2 g of Cu-Zr-MOF powder to the solution, stir at room temperature for 1 hour, centrifuge (8000 r / min, 5 min), wash with water for the last time, dynamically dry at 80°C in vacuum overnight, grind to obtain powder after drying. The powder is calcined at 750°C at 2.5°C / min for 3 hours to obtain Pd-Cu-Zr catalyst material.
[0032] Example 5
[0033] (1) 1,3,5-benzenetricarboxylic acid H 3 BTC (2.52 g) and ZrClO 2 8H 2 O (11.64 g) was dissolved in a flask containing DMF / formic acid (300 mL / 300 mL), stirred for 1 h until completely dissolved, and then rapidly heated to 130 ° C using the reflux condensation method and maintained for 48 h. A white precipitate was obtained by centrifugation (8000 r / min, 5 min), which was washed with DMF and then shaken for 10-15 min. This operation was repeated 3 times, and dynamically dried at 80 ° C overnight in a vacuum, and then ground to obtain white powder Zr-MOF.
[0034] (2) Take 0.1 ml of 54 mg Pd / ml palladium nitrate solution and dissolve it in 150 ml of deionized water, add 2 g of Zr-MOF powder to the solution, stir at room temperature for 1 hour, centrifuge (8000 r / min, 5 min), wash with water for the last time, dynamically dry at 80°C in vacuum overnight, grind to obtain powder after drying. The powder is calcined at 750°C at 2.5°C / min for 3 hours to obtain Pd-Zr catalyst material.
[0035] Example 6
[0036] (1) 1,3,5-benzenetricarboxylic acid H 3 BTC(2.52g), ZrClO 28H 2 O(9.86g) and 50%Mn(NO 3 ) 2 (1.93 g) was dissolved in a flask containing DMF / formic acid (300 mL / 300 mL), stirred for 1 h until completely dissolved, and then rapidly heated to 130 ° C using the reflux condensation method and maintained for 48 h. A white precipitate was obtained by centrifugation (8000 r / min, 5 min), which was washed with DMF and then shaken for 10-15 min. This operation was repeated 3 times, and then dynamically dried at 80 ° C overnight in a vacuum, and then ground to obtain white powder Mn-Zr-MOF.
[0037] (2) Take 0.048 ml of 113.5 mg Ru / ml ruthenium chloride solution and dissolve it in 150 ml of deionized water. Add 2 g of Mn-Zr-MOF powder to the solution, stir at room temperature for 1 hour, centrifuge (8000 r / min, 5 min), wash with water for the last time, dynamically dry at 80°C in vacuum overnight, and grind to obtain powder after drying. The powder is calcined at 750°C at 2.5°C / min for 3 hours to obtain Ru-Mn-Zr catalyst material.
[0038] Example 7
[0039] (1) 1,3,5-benzenetricarboxylic acid H 3 BTC(2.52g), ZrClO 2 8H 2 O(9.86g) and 50%Mn(NO 3 ) 2 (1.93 g) was dissolved in a flask containing DMF / formic acid (300 mL / 300 mL), stirred for 1 h until completely dissolved, and then rapidly heated to 130 ° C using the reflux condensation method and maintained for 48 h. A white precipitate was obtained by centrifugation (8000 r / min, 5 min), which was washed with DMF and then shaken for 10-15 min. This operation was repeated 3 times, and then dynamically dried at 80 ° C overnight in a vacuum, and then ground to obtain white powder Mn-Zr-MOF.
[0040] (2) Take 0.068 ml of 80.7 mg Pt / ml chloroplatinic acid solution and dissolve it in 150 ml of deionized water. Add 2 g of Mn-Zr-MOF powder to the solution, stir at room temperature for 1 hour, centrifuge (8000 r / min, 5 min), wash with water for the last time, dynamically dry at 80°C in vacuum overnight, and grind to obtain powder after drying. The powder is calcined at 750°C at 2.5°C / min for 3 hours to obtain Pt-Mn-Zr catalyst material.
[0041] Figure 2 , Figure 3The catalytic activity of toluene was tested under the following conditions: the toluene concentration was 500 ppm, the rest was air, and the total flow rate was 300 mL min -1 , the reaction mass space velocity is 120,000 mL·h -1 ·g -1 ; Figure 2 The activity of the catalyst doped with metal Mn, Ce, Co or Cu is significantly improved compared with that of the undoped Pd-Zr, among which the activity of Example 1 doped with metal Mn is the best. Figure 3 For the catalytic oxidation of toluene loaded with different precious metals Ru, Pd or Pt, Example 1 loaded with precious metal Pd has the best activity. Figure 4 This indicates that the catalyst of Example 1 after calcination still maintains the octahedral morphology of MOF without collapse. Figure 5 The EDS surface scan of the catalyst shows that the dispersion of the catalyst Pd prepared in Example 1 is significantly improved compared with that in Example 5, indicating that doping the metal organic framework with metal and introducing precious metals can greatly improve the dispersion of precious metals compared with the catalyst not doped with metal (Example 5).
[0042] 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 present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.
[0043] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.
Claims
1. A metal-doped zirconium-based MOF-supported noble metal catalyst, characterized in that: It is prepared with metal-doped zirconium-based MOF as a precursor, and has a structural formula of MN-Zr, wherein M is a precious metal such as Ru, Pd or Pt, and the mass percentage of the precious metal is 0.01% to 10%, and N is a doping metal such as Mn, Ce, Co or Cu, and the molar percentage of the doping metal is 10% to 30%.
2. A method for preparing a metal-doped zirconium-based MOF-supported noble metal catalyst, characterized in that: The following steps are involved: (1) 1,3,5-benzenetricarboxylic acid H3BTC, ZrClO2·8H2O and metal N precursor are dissolved in DMF / formic acid, stirred until completely dissolved, and rapidly heated to 100-130°C using a reflux condensation method, and maintained for 12-48 hours; a white precipitate is obtained by centrifugation, and the precipitate is washed with DMF, and then shaken for 10-15 minutes, and this operation is repeated multiple times, and vacuum dynamic drying is performed overnight, and after drying, the white powder N-Zr-MOF is obtained by grinding; (2) Dissolve the M solution in deionized water, add N-Zr-MOF powder to the solution, stir at room temperature, centrifuge, dynamically dry overnight at 80-130°C in vacuum, and grind to obtain powder after drying; calcine the powder at 750°C for 2-6h to obtain MN-Zr, where M is a precious metal Ru, Pd or Pt, and N is a doped metal Mn, Ce, Co or Cu.
3. Use of the metal-doped zirconium-based MOF-supported noble metal catalyst according to claim 1 or the metal-doped zirconium-based MOF-supported noble metal catalyst prepared by the method according to claim 2 in the catalytic removal of VOCs gas.
4. The use according to claim 3, characterized in that: Used for catalytic removal of toluene VOCs gas, the specific process is: using air as an oxidant for combustion reaction, the reaction temperature is 100 ~ 700 ℃.