Supported metal catalyst, preparation method thereof and VOCs treatment method
By loading PdAu core-shell bimetal on a three-dimensional multi-stage structure TiO2 support, a VOCs catalyst with low cost and good catalytic effect was prepared, which solved the problem of high catalyst cost or poor effect in the prior art, and achieved efficient oxidation and decomposition of VOCs.
Patent Information
- Application Number
- CN201811642644.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2018-12-29
- Publication Date
- 2025-06-13
- Estimated Expiration
- 2038-12-29
AI Technical Summary
Existing VOCs catalysts have high cost or poor catalytic effects, making it difficult to find a balanced solution in environmental protection.
A three-dimensional multi-stage structure TiO2 is used as a support and the PdAu core-shell bimetal is supported. A supported metal catalyst is prepared through hydrothermal reaction and calcination steps to improve catalytic activity and stability.
High-efficiency catalytic oxidation of VOCs is achieved, the complete oxidation temperature is reduced, the carbon dioxide selectivity is improved, and the cost is relatively low.
Smart Images
Figure CN109647386B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of energy conservation and environmental protection, and in particular relates to a supported metal catalyst, a preparation method thereof and a VOCs treatment method. Background Art
[0002] Volatile organic compounds (VOCs) refer to organic compounds with a saturated vapor pressure greater than 70Pa at room temperature and a boiling point below 260°C at normal pressure, including alkanes, aromatics, halogenated hydrocarbons, alcohols, ethers, fats, etc. Common industrial sources include petrochemicals, printing, spraying and other industries. Most VOCs are toxic and have irritating odors, and some are carcinogenic, which poses a huge threat to human health. VOCs can also undergo photochemical reactions with nitrogen oxides in the atmosphere under the action of sunlight to produce more harmful photochemical smog, which has become one of the main air pollutants in my country in recent years. With the promulgation of increasingly stringent laws and regulations in my country, VOCs control and prevention has become one of the major issues that need to be urgently addressed in today's environmental protection work.
[0003] At present, the main VOCs pollution control technologies include adsorption, absorption, combustion and condensation, and the combustion method includes catalytic combustion. Catalytic combustion is a purification method that uses a catalyst to oxidize and decompose combustible substances in exhaust gas at a temperature below its ignition point (300-450°C). Compared with the current mainstream thermal storage combustion method, the catalytic combustion method has the advantages of less auxiliary fuel required, low energy consumption (50% of the thermal storage combustion method), less secondary pollution, and small equipment size.
[0004] The prior art discloses a variety of VOCs catalysts, and their active components are mainly divided into two categories: (1) precious metal type, such as Pt, Pd, and PtPd bimetallic; (2) non-precious metal type, such as Mn, Cu, Ce, etc. Although traditional precious metal catalysts have good catalytic effects, they are relatively expensive; although non-precious metal catalysts have low costs, they have poor catalytic effects. Therefore, researching and developing VOCs catalysts with low costs and good catalytic effects is of great significance for environmental protection. Summary of the invention
[0005] In view of this, the object of the present invention is to provide a supported metal catalyst, a preparation method thereof and a VOCs treatment method. The supported catalyst provided by the present invention has relatively low cost and good catalytic activity.
[0006] The present invention provides a supported metal catalyst, comprising: a three-dimensional multi-level structure TiO 2 and loaded on the TiO 2 PdAu core-shell bimetal on;
[0007] Wherein, the three-dimensional multi-level structure TiO 2 TiO2 Nanoparticle-assembled nanorods and / or TiO 2 Nanoparticle-assembled nanosheets are formed.
[0008] The present invention is based on TiO 2 A three-dimensional hierarchical structure TiO formed by nanoparticle-assembled nanorods and / or nanosheets of low-dimensional structures 2 As a carrier, PdAu core-shell bimetal is loaded. TiO 2 The three-dimensional hierarchical structure assembled by nanoparticles has a good loading effect, which can highly disperse the PdAu core-shell bimetal on its surface and inhibit the surface migration of nanoparticles during the reaction, and can obtain better stability in the overall geometric configuration and maintain the size effect of the nanomaterials; TiO 2 The three-dimensional hierarchical structure carrier assembled by nanoparticles can strengthen the gas-solid phase reaction, obtain good mass transfer and heat transfer effects and strengthen the reaction; while the PdAu core-shell structure has a strong electronic effect, which can effectively reduce the reaction activation energy and the required reaction temperature; there is a strong interaction between the carrier and the metal, which makes the surface nanoparticles have increased anti-sintering property and increases their service life.
[0009] In one embodiment, the three-dimensional hierarchical structure TiO 2 is formed by TiO 2 Nanoparticle-assembled nanorods and TiO 2 Nanoparticle-assembled nanosheets are formed.
[0010] In one embodiment, the three-dimensional hierarchical structure TiO 2 uses TiO 2 Nanoparticle-assembled nanorods as dendritic skeletons, and TiO 2 Nanoparticle-assembled nanosheets grow and distribute along the dendritic skeletons, similar to a downy shape.
[0011] In one embodiment, the three-dimensional hierarchical structure TiO 2 uses TiO 2 Nanoparticle-assembled nanorods as dendritic skeletons, and TiO 2 Nanoparticle-assembled nanosheets grow and distribute along the dendritic skeletons, similar to a downy shape, and their particle size is 0.5 μm to 3 μm.
[0012] In one embodiment, the PdAu core-shell bimetal has Pd as the shell and Au as the core.
[0013] In one embodiment, the loading amount of Pd in the PdAu core-shell bimetal is 1 to 10 wt%, and the loading amount of Au is 1 to 10 wt%.
[0014] In one embodiment, the loading of Pd in the PdAu core-shell bimetal is 1-5 wt%, and the loading of Au is 1-5 wt%.
[0015] In one embodiment, in the PdAu core-shell bimetal, the atomic ratio of Pd to Au is 1-3:1-3.
[0016] In one embodiment, the loading of Pd in the PdAu core-shell bimetal is 3 wt%, and the atomic ratio of Pd to Au is 1:1; in one embodiment, the loading of Pd in the PdAu core-shell bimetal is 3 wt%, and the atomic ratio of Pd to Au is 1:3; in one embodiment, the loading of Pd in the PdAu core-shell bimetal is 3 wt%, and the atomic ratio of Pd to Au is 3:1.
[0017] In one embodiment, the size of the PdAu core-shell bimetal is 2 nm to 16 nm.
[0018] In one embodiment, the thickness of the Pd shell in the PdAu core-shell bimetal is 1 nm to 1.5 nm.
[0019] When the catalyst provided by the present invention is used for catalytic oxidation of VOCs, the nano-sized PdAu core-shell metal particles and the three-dimensional hierarchical structure TiO 2 support have strong metal interaction forces, which can reduce the reaction temperature (i.e., activation energy) and improve the catalytic oxidation effect on VOCs. The catalyst prepared by the present invention has good performance, stable structure and high atomic utilization rate of the active phase. Experimental results show that the complete oxidation temperature of benzene by the catalyst provided by the present invention can be as low as 175 °C, and the carbon dioxide selectivity ≥ 99%.
[0020] The present invention also provides a three-dimensional hierarchical structure TiO 2 , which is formed by nanorods assembled from TiO 2 nanoparticles and nanosheets assembled from TiO 2 nanoparticles. The nanorods assembled from TiO 2 nanoparticles are dendritic skeletons, and the nanosheets assembled from TiO 2 nanoparticles grow and distribute along the dendritic skeletons. Specifically, the three-dimensional hierarchical structure TiO 2 is in the shape of down feathers and can be used as a catalyst support to load metal catalysts.
[0021] The present invention also provides a supported metal catalyst, including a three-dimensional hierarchical structure TiO 2 and an active component supported on the TiO 2 ;
[0022] The three-dimensional hierarchical structure TiO 2 is composed of TiO 2Nanoparticle-assembled nanorods and TiO 2 Nanoparticle-assembled nanosheets are formed, TiO 2 The nanoparticle-assembled nanorods are dendritic skeletons, TiO 2 The nanoparticle-assembled nanosheets grow and distribute along the dendritic skeleton;
[0023] The active component is selected from Pd and Au.
[0024] In the present invention, the three-dimensional hierarchical structure TiO 2 is the above-mentioned downy structure, and can support Pd and Au. Among them, Pd and Au can exist in the form of single components of Pd and Au, can exist in the form of PdAu bimetals, can also exist in the form of core-shell structures, and can exist simultaneously in the above forms; when existing in the form of core-shell structures, Pd can be the shell and Au can be the core, or Au can be the shell and Pd can be the core.
[0025] The present invention also provides a preparation method of a supported metal catalyst, comprising the following steps:
[0026] After hydrothermal reaction of glacial acetic acid and tetrabutyl titanate, calcination is carried out to obtain a three-dimensional hierarchical structure TiO 2 ;
[0027] The three-dimensional hierarchical structure TiO 2 is impregnated with Pd salt and Au salt, and a supported metal catalyst is obtained after reduction.
[0028] In the present invention, hydrothermal reaction is carried out using glacial acetic acid and tetrabutyl titanate as raw materials, and then calcination is carried out to obtain a three-dimensional hierarchical structure TiO 2 . Specifically, in the present invention, tetrabutyl titanate is added dropwise to glacial acetic acid under stirring conditions, and after stirring, hydrothermal reaction is carried out to obtain a carrier precursor. In one embodiment, the volume ratio of glacial acetic acid to tetrabutyl titanate is 20-60:1. In one embodiment, the volume ratio of glacial acetic acid to tetrabutyl titanate is 40:1. In one embodiment, the stirring condition is 800-1500 r / min; in one embodiment, the stirring condition is 1000 r / min. In one embodiment, the stirring time is 30-60 min. In one embodiment, the stirring time is 45 min. After stirring, hydrothermal reaction is carried out in a hydrothermal reaction kettle, the temperature of the hydrothermal reaction is 120-180 °C, and the time is 10-20 h. In one embodiment, the temperature of the hydrothermal reaction is 150 °C and the time is 15 h. After the hydrothermal reaction is completed, it is cooled, washed, and dried to obtain a carrier precursor. In one embodiment, the drying temperature is 80-120 °C. In one embodiment, the drying temperature is 100 °C. After obtaining the carrier precursor, it is calcined, and TiO is generated during the calcination process 2nanoparticles, and assembled into dendritic framework-shaped nanorods and nanosheets assembled on the dendritic framework to obtain a three-dimensional hierarchical structure TiO 2 In one embodiment, the calcination temperature is 500-1000 °C, and the calcination time is 1-5 h.
[0029] to obtain a three-dimensional hierarchical structure TiO 2 After that, it is impregnated with Pd salt and Au salt, and a supported metal catalyst is obtained after reduction. Specifically, after obtaining a three-dimensional hierarchical structure TiO 2 After that, it is dispersed in a solvent, Pd salt and Au salt are added, and the mixture is uniformly mixed under ultrasonic conditions. After drying to a powder state, reduction is carried out. In one embodiment, the dispersion solvent is selected from ethanol or water. In one embodiment, the reduction is carried out in a He / H 2 mixed atmosphere, the reduction temperature is 200-300 °C, the heating rate is 1-5 °C / min, and the constant temperature time is 1-4 h. In one embodiment, the Pd salt is selected from one or two of palladium nitrate and palladium chloride, and the Au salt is selected from one or two of chloroauric acid hydrate and gold chloride. In one embodiment, the Pd salt concentration is 5 wt%-15 wt%, and the Au salt concentration is 5 mg / mL-15 mg / mL. In one embodiment, the Pd salt is a nitric acid solution of 10 wt% palladium nitrate, and the Au salt is a solution of 10 mg / mL chloroauric acid trihydrate. In one embodiment, the loading amount of Pd in the PdAu core-shell bimetal is 1-10 wt%, and the loading amount of Au is 1-10 wt%. In one embodiment, the loading amount of Pd in the PdAu core-shell bimetal is 1-5 wt%, and the loading amount of Au is 1-5 wt%. In one embodiment, in the PdAu core-shell bimetal, the atomic ratio of Pd to Au is 1-3:1-3. In one embodiment, the loading amount of Pd in the PdAu core-shell bimetal is 3 wt%, and the atomic ratio of Pd to Au is 1:1; in one embodiment, the loading amount of Pd in the PdAu core-shell bimetal is 3 wt%, and the atomic ratio of Pd to Au is 1:3; in one embodiment, the loading amount of Pd in the PdAu core-shell bimetal is 3 wt%, and the atomic ratio of Pd to Au is 3:1.
[0030] The present invention also provides a method for treating VOCs, including:
[0031] VOCs are combusted under the action of the supported metal catalyst described in the above technical solution or the supported metal catalyst prepared by the preparation method described in the above technical solution.
[0032] In one embodiment, the VOCs contain benzene.
[0033] The experimental results show that the complete oxidation temperature of benzene by the catalyst provided by the present invention can be as low as 175 °C, and the carbon dioxide selectivity ≥ 99%. Description of the Drawings
[0034] Figure 1 It is the process flow chart for preparing the catalyst in the embodiment of the present invention;
[0035] Figure 2 It is the TEM image of the catalyst prepared in Example 1 of the present invention at 0.5 μm;
[0036] Figure 3 It is the TEM image of the catalyst prepared in Example 1 of the present invention at 200 nm;
[0037] Figure 4 It is the three-dimensional multi-level structure TiO 2 STEM image of the carrier;
[0038] Figure 5 It is the STEM image of the catalyst prepared in Example 1 of the present invention;
[0039] Figure 6 It is the HRTEM image of the catalyst prepared in Example 1 of the present invention;
[0040] Figure 7 It is the Mapping image of the catalyst prepared in Example 1 of the present invention;
[0041] Figure 8 is the XPS spectrum of the catalyst sample prepared in the embodiment of the present invention;
[0042] Figure 9 It is the TEM image of the catalyst prepared in the embodiment of the present invention before the catalytic oxidation reaction;
[0043] Figure 10 It is the TEM image of the catalyst prepared in the embodiment of the present invention after the catalytic oxidation reaction. Detailed Embodiments
[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0045] Example 1
[0046] According to Figure 1 The process flow shown, prepare the catalyst, Figure 1This is the process flow diagram for preparing the catalyst in the embodiments of the present invention. First, glacial acetic acid and tetrabutyl titanate are mixed and stirred, and then subjected to solvothermal treatment until the reaction is complete. Then, centrifugal washing is carried out to obtain the precursor, and finally, calcination in a muffle furnace is performed to obtain the support. Next, the support is impregnated with Pd salt and Au salt, and reduction in an atmosphere tube furnace is carried out to obtain the catalyst.
[0047] The specific steps are as follows:
[0048] (1) Pour 60 ml of glacial acetic acid into a 100 ml polytetrafluoroethylene inner liner, stir at 1000 r / min, and gradually add 1.5 ml of tetrabutyl titanate dropwise, and stir for 45 min. Place the polytetrafluoroethylene inner liner containing the reaction solution into a hydrothermal reaction kettle, and place it in an electric heating box to heat at a constant temperature of 150 °C for 15 h. After the reaction is completed, wait for it to cool to room temperature, and then carry out centrifugal washing. After the washing is completed, dry it in a vacuum drying oven at 100 °C to obtain the support precursor. Place the support precursor in a muffle furnace and calcine it at 800 °C for 2 h to obtain a three-dimensional hierarchical structure TiO 2 support. (2) Using the impregnation method, ultrasonically disperse 0.1 g of the obtained support in an ethanol solution. Prepare a palladium nitrate solution (10 wt% in 10 wt% nitric acid, 60 μL) and a chloroauric acid trihydrate solution (10 mg / mL, 1.14 mL). The specific feeding ratio of Pd and Au is added according to 3 wt% of Pd in Pd / TiO 2 , and the atomic ratio of Pd:Au is 1:1. Ultrasonically mix for 10 min until fully mixed evenly, stir dry at 45 °C until it becomes powdery. Put the obtained powder into an atmosphere tube furnace, and pass a He / H 2 mixed gas at 100:25 sccm for calcination at 250 °C, with a heating rate of 3 °C / min and a constant temperature for 2 h, and then it can be obtained.
[0049] See Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8, Figure 9 and Figure 10 , Figure 2 This is the TEM image of the catalyst prepared in Example 1 of the present invention at 0.5 μm. Figure 3 This is the TEM image of the catalyst prepared in Example 1 of the present invention at 200 nm. Figure 4 This is the STEM image of the three-dimensional hierarchical structure TiO 2 support prepared in Example 1 of the present invention. Figure 5 This is the STEM image of the catalyst prepared in Example 1 of the present invention. Figure 6 This is the HRTEM image of the catalyst prepared in Example 1 of the present invention. Figure 7The Mapping diagram of the catalyst prepared in Example 1 of the present invention, and Figure 8 is the XPS spectrum of the catalyst sample prepared in the examples of the present invention. Figure 9 The TEM diagram of the catalyst prepared in the examples of the present invention before the catalytic oxidation reaction. Figure 10 The TEM diagram of the catalyst prepared in the examples of the present invention after the catalytic oxidation reaction. From Figure 2 , Figure 3 and Figure 4 it can be seen that in the catalyst prepared in the present invention, the three-dimensional hierarchical structure TiO 2 support takes the nanorods assembled by TiO 2 nanoparticles as the dendritic skeleton, and the TiO 2 nanoparticles grow along the skeleton and assemble into nanosheets, similar to a down-like structure, with a size of about 3 μm. From Figure 5 it can be seen that the catalyst prepared in the present invention includes a down-like structure TiO 2 support and metal particles loaded thereon; from Figure 6 it can be seen that the particle size of the loaded metal particles is about 5 nm; from Figure 7 it can be seen that the loaded metal particles are of a core-shell structure, with Pd as the shell and Au as the core, and the thickness of the Pd shell is about 1 nm; from Figure 8(A), Figure 8(B) and Figure 8(C), it can be seen that the main components of the catalyst prepared in the present invention are Pd, Au and Ti, and there is a strong electronic interaction between Pd and Au on the surface of TiO 2 , and at the same time, there is a strong electronic interaction with the TiO 2 support; from Figure 9 and Figure 10 it can be seen that the structure size of the PdAu bimetallic nanoparticles on the surface of the catalyst prepared in the present invention has not changed significantly after a long-term reaction, and its anti-sintering performance is excellent.
[0050] Using this catalyst for the catalytic oxidation of benzene, the results show that the complete oxidation temperature of benzene is 175 °C, and the carbon dioxide selectivity ≥ 99%.
[0051] Example 2
[0052] Except that the carrier precursor is calcined in a muffle furnace at 500 °C for 2 h, the rest is the same as in Example 1. The complete oxidation temperature of benzene by the catalyst is 225 °C, and the carbon dioxide selectivity ≥ 99%.
[0053] Example 3
[0054] Except that the carrier precursor is calcined in a muffle furnace at 1000 °C for 2 h, the rest is the same as in Example 1. The complete oxidation temperature of benzene by the catalyst is 210 °C, and the carbon dioxide selectivity ≥ 99%.
[0055] Example 4
[0056] Except that the reduction in the atmosphere tube furnace was carried out at a constant temperature for 1 h, the rest was the same as in Example 1. The complete oxidation temperature of benzene by the catalyst was 205 °C, and the carbon dioxide selectivity was ≥99%.
[0057] Example 5
[0058] Except that the reduction in the atmosphere tube furnace was carried out at a constant temperature for 4 h, the rest was the same as in Example 1. The complete oxidation temperature of benzene by the catalyst was 200 °C, and the carbon dioxide selectivity was ≥99%.
[0059] Example 6
[0060] Except that the Pd:Au atomic ratio was 3:1, the rest was the same as in Example 1. The complete oxidation temperature of benzene by the catalyst was 195 °C, and the carbon dioxide selectivity was ≥99%.
[0061] Example 7
[0062] Except that the Pd:Au atomic ratio was 1:3, the rest was the same as in Example 1. The complete oxidation temperature of benzene by the catalyst was 200 °C, and the carbon dioxide selectivity was ≥99%.
[0063] Comparative Example 1
[0064] Using the impregnation method, 0.1 g of commercial TiO 2 (Degussa P25) was ultrasonically dispersed in an ethanol solution; the prepared palladium nitrate solution (10 wt% in 10 wt% nitric acid, 60 μL) and chloroauric acid trihydrate solution (10 mg / mL, 1.14 mL) were used, and the specific Pd and Au feeding ratios were added according to 3 wt% of Pd in Pd / TiO 2 , and the Pd:Au atomic ratio was 1:1. After ultrasonic mixing for 10 min to be fully uniform, it was dried to a powder at 45 °C. The obtained powder was put into an atmosphere tube furnace, and a He / H 2 mixed gas of 100:25 sccm was used for calcination at 250 °C, with a heating rate of 3 °C / min and a constant temperature of 2 h to obtain the catalyst. The complete oxidation temperature of benzene by the catalyst was 260 °C, and the carbon dioxide selectivity was ≥99%.
[0065] Comparative Example 2
[0066] (1) 60 ml of CH 3Pour COOH (acetic acid) into a 100 ml polytetrafluoroethylene inner container, stir at 1000 r / min, dropwise add 1.5 ml of tetrabutyl titanate, and stir for 45 min; put the polytetrafluoro inner container containing the reaction solution into a hydrothermal reaction kettle, place it in an electric heating box, and heat it at a constant temperature of 150 °C for 15 h; after the reaction is completed, wait for it to cool to room temperature, and centrifuge and wash; after the washing is completed, dry it in a vacuum drying oven at 100 °C to obtain a carrier precursor; place the carrier precursor in a muffle furnace and calcine it at 800 °C for 2 h to obtain a three-dimensional hierarchical structure of TiO 2 carrier.
[0067] Using the impregnation method, ultrasonically disperse 0.1 g of the carrier into an ethanol solution; add the prepared palladium nitrate solution (10 wt% in 10 wt% nitric acid, 60 μL) to the above carrier dispersion solution, ultrasonically mix for 10 min to mix evenly, stir dry at 45 °C until it becomes powdery, put the obtained powder into an atmospheric tube furnace, and pass He / H 2 The mixed gas of 100:25 sccm is calcined at 250 °C, the heating rate is 3 °C / min, and the constant temperature is 2 h to obtain it.
[0068] The complete oxidation temperature of benzene by the catalyst is 255 °C, and the carbon dioxide selectivity ≥ 99%.
[0069] Comparative Example 3
[0070] (1) Pour 60 ml of CH 3 COOH (acetic acid) into a 100 ml polytetrafluoroethylene inner container, stir at 1000 r / min, dropwise add 1.5 ml of tetrabutyl titanate, and stir for 45 min; put the polytetrafluoro inner container containing the reaction solution into a hydrothermal reaction kettle, place it in an electric heating box, and heat it at a constant temperature of 150 °C for 15 h; after the reaction is completed, wait for it to cool to room temperature, and centrifuge and wash; after the washing is completed, dry it in a vacuum drying oven at 100 °C to obtain a carrier precursor; place the carrier precursor in a muffle furnace and calcine it at 800 °C for 2 h to obtain a three-dimensional hierarchical structure of TiO 2 carrier.
[0071] (2) Using the impregnation method, ultrasonically disperse 0.1 g of the carrier into an ethanol solution; add the prepared chloroauric acid trihydrate solution (10 mg / mL, 1.14 mL) to the above carrier dispersion solution, ultrasonically mix for 10 min to mix evenly, stir dry at 45 °C until it becomes powdery, put the obtained powder into an atmospheric tube furnace, and pass He / H 2 The mixed gas of 100:25 sccm is calcined at 250 °C, the heating rate is 3 °C / min, and the constant temperature is 2 h to obtain it.
[0072] The complete oxidation temperature of benzene by the catalyst is 340 °C, and the carbon dioxide selectivity ≥ 99%.
[0073] As can be seen from the above embodiments and comparative examples, the catalytic performance of the commercially available TiO 2 supported PdAu bimetallic catalyst is lower than that of the three-dimensional hierarchical structure TiO 2 supported PdAu bimetallic catalyst of the present invention. Due to the three-dimensional hierarchical structure TiO 2 supported PdAu nanoparticles, the kinetics in the three-dimensional hierarchical structure gas-solid phase reaction process is superior to that of commercial P25 nanoparticles; from the electron binding energy analysis, it can be seen that the strong electronic effect generated between Pd and Au, PdAu and the three-dimensional hierarchical structure TiO 2 causes a strong interaction force between the support and the metal, making the catalytic activity and stability of the catalyst superior to those of single-active-component catalysts and commercial catalysts.
[0074] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.
Claims
1. A catalytic combustion treatment method for VOCs, Characterized in that, Including: VOCs are combusted under the action of a supported metal catalyst, and the supported metal catalyst includes: three-dimensional hierarchical structure TiO 2 and PdAu core-shell bimetal supported on the TiO 2 ; Among them, the three-dimensional multi-level structure TiO 2 is composed of nanorods assembled by TiO 2 nanoparticles and nanosheets assembled by TiO 2 nanoparticles; The supported metal catalyst is prepared by the following method: After the hydrothermal reaction of glacial acetic acid and tetrabutyl titanate, calcination is carried out to obtain three-dimensional hierarchical structure TiO 2 ; Impregnate the three-dimensional multi-level structured TiO 2 with Pd salt and Au salt, and obtain a supported metal catalyst after reduction.
2. The treatment method according to claim 1, Characterized in that, The three-dimensional multi-level structure TiO 2 Using the nanorods assembled by TiO 2 nanoparticles as the dendritic framework, the nanosheets assembled by TiO 2 nanoparticles grow and distribute along the dendritic framework.
3. The treatment method according to claim 2, Characterized in that, The size of the three-dimensional multi-level structure TiO 2 is 0.5 μm to 3 μm.
4. The treatment method according to claim 1, Characterized in that, The PdAu core-shell bimetal has Pd as the shell and Au as the core.
5. The treatment method according to claim 4, Characterized in that, The loading amount of Pd in the PdAu core-shell bimetal is 1-10 wt%; In the PdAu core-shell bimetal, the atomic ratio of Pd to Au is 1-3:1-3.
6. The treatment method according to claim 1, Characterized in that, The size of the PdAu core-shell bimetal is 2 nm to 16 nm; The thickness of the Pd shell in the PdAu core-shell bimetal is 1 nm to 1.5 nm.