High-activity VOCs waste gas treatment composite catalyst and preparation method thereof
By combining manganese/cerium/bismuth/lanthanum quaternary composite metal oxides with modified attapulgite-clinoptilolite carrier, along with tungsten-ytterbium composite additives and microwave calcination process, a highly active VOCs waste gas treatment catalyst was prepared. This solved the problems of low degradation efficiency and poor stability of chlorine-containing VOCs in existing technologies, and achieved low-temperature broad-spectrum degradation and long-term stable operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUZHOU HENGLU ZHICHUANG LOW CARBON TECHNOLOGY CO LTD
- Filing Date
- 2026-04-07
- Publication Date
- 2026-06-05
AI Technical Summary
Existing VOCs catalytic catalysts suffer from insufficient activity, easy poisoning, generation of byproducts, and high cost when degrading chlorine-containing pollutants. Furthermore, the carrier materials and preparation processes are inadequate and difficult to adapt to complex industrial conditions.
A highly active composite catalyst for VOCs waste gas treatment was prepared by using a quaternary composite metal oxide of manganese/cerium/bismuth/lanthanum as the active component, modifying the attapulgite-clinoptilolite composite carrier, and combining it with a tungsten-ytterbium composite additive and a high-temperature resistant binder through microwave segmented calcination.
It achieves low-temperature and efficient degradation of conventional VOCs such as benzene, toluene, and formaldehyde, as well as chlorine-containing VOCs such as dichloromethane and trichloroethylene. The stability is improved, and the degradation products are CO2 and inorganic chlorides. There is no secondary pollution, the cost is low, and it is suitable for VOCs waste gas treatment in multiple industries.
Smart Images
Figure CN122141653A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of environmental catalysis technology, and in particular relates to a highly active composite catalyst for VOCs waste gas treatment and its preparation method. Background Technology
[0002] Volatile organic compounds (VOCs) are one of the core air pollutants that cause photochemical smog, haze, and ozone layer depletion. They are widely derived from industries such as coating, printing, chemical, pharmaceutical, and electronics manufacturing. They include not only conventional hydrocarbons and aldehydes such as benzene, toluene, formaldehyde, and ethyl acetate, but also chlorinated VOCs (CVOCs) such as dichloromethane, trichloroethylene, and chlorobenzene. These chlorinated pollutants are more toxic, more difficult to degrade, and easily cause catalyst poisoning and deactivation, making them a key focus and challenge in industrial VOCs control.
[0003] Catalytic combustion, with its advantages of high degradation efficiency, no secondary pollution, and low energy consumption, has become a core technology for end-of-pipe treatment of industrial VOCs. Its performance largely depends on the catalytic catalyst. Existing VOCs catalytic catalysts mainly face the following technical bottlenecks: 1. Although precious metal catalysts have good low-temperature activity, they are expensive, scarce, and easily poisoned and deactivated by chlorine and sulfur impurities, which limits their large-scale application. 2. Conventional non-precious metal catalysts mostly use single or binary / ternary metal oxides as active components. They only have a certain degradation effect on conventional VOCs such as benzene series compounds and aldehydes. They have extremely low degradation efficiency for chlorine-containing VOCs, are prone to chlorine poisoning and surface carbon accumulation, and are also prone to generating harmful polychlorinated byproducts, causing secondary pollution. 3. The carriers mostly use single materials such as ordinary zeolite and alumina, which have limited specific surface area, weak adsorption and enrichment capacity for VOCs, and uncontrollable acid sites. They cannot meet the dechlorination requirements of the degradation process of chlorine-containing VOCs. The active components are prone to agglomeration and have weak binding force with the carrier, and are easily lost with long-term use. 4. Traditional preparation processes often employ impregnation and mechanical mixing methods, combined with high-temperature calcination in muffle furnaces. These methods suffer from problems such as poor dispersion of active components, long calcination time, easy grain growth, and low oxygen vacancy content, resulting in insufficient catalytic activity and poor stability of the catalyst, making it difficult to meet the long-term operating requirements of complex industrial conditions. Summary of the Invention
[0004] The purpose of this invention is to provide a highly active composite catalyst for VOCs waste gas treatment and its preparation method in order to solve the above-mentioned problems.
[0005] On the one hand, in order to achieve the above objectives, the present invention adopts the following technical solution: a highly active composite catalyst for VOCs waste gas treatment, which is composed of the following components in weight percentage: 3-22% manganese / cerium / bismuth / lanthanum quaternary composite metal oxide, 70-92% modified attapulgite-clinoptilolite composite carrier, 2-7% tungsten-ytterbium composite additive, and 0.8-2.5% high-temperature resistant binder; In the manganese / cerium / bismuth / lanthanum quaternary composite metal oxide, the molar ratio of manganese, cerium, bismuth, and lanthanum is 1:(0.6-1.0):(0.3-0.6):(0.2-0.4). In the modified attapulgite-clinoplastite composite carrier, the mass ratio of attapulgite to clinoplastite is (2-4):6; The tungsten-ytterbium composite additive is a mixture of tungsten trioxide and ytterbium oxide, with a mass ratio of tungsten trioxide to ytterbium oxide of (1-2):1.
[0006] As a further description of the above technical solution: The high-temperature resistant adhesive is a compound of amino-modified silica sol and polyvinylidene fluoride, with a mass ratio of amino-modified silica sol to polyvinylidene fluoride of (3-5):1.
[0007] On the other hand, in order to achieve the above objectives, the present invention employs the following method: a method for preparing a highly active composite catalyst for VOCs waste gas treatment, comprising the following steps: 1) Preparation of manganese / cerium / bismuth / lanthanum quaternary composite metal oxide precursor: 50% manganese nitrate solution, cerium nitrate, bismuth nitrate, and lanthanum nitrate were added to deionized water at the target molar ratio and stirred to prepare a mixed salt solution; a composite complexing agent was added to the mixed salt solution, and after stirring at room temperature, the pH was adjusted to 8.0-9.0 with ammonia water to form a homogeneous sol; after water bath aging and drying, the manganese / cerium / bismuth / lanthanum quaternary composite metal oxide precursor was obtained. 2) Preparation of modified attapulgite-clinoptilolite composite carrier: Attapulgite and clinoptilolite were mixed in a mass ratio, and after acid activation treatment with hydrochloric acid solution, the mixture was washed, dried, and sieved to obtain an acid-activated composite carrier; a silane coupling agent was prepared into a modification solution and hydrolyzed, and then the acid-activated composite carrier was added to the modification solution for graft modification. After washing, drying, and calcination, the modified attapulgite-clinoptilolite composite carrier was obtained. 3) Preparation of tungsten-ytterbium composite additive: Dissolve tungsten nitrate and ytterbium nitrate in deionized water at the target mass ratio, add polyethylene glycol dispersant, stir evenly, adjust the pH to neutral with ammonium bicarbonate solution, and obtain tungsten-ytterbium composite additive after precipitation, filtration, drying, calcination, grinding and sieving. 4) Preparation of high-temperature resistant adhesive solution: Add amino-modified silica sol and polyvinylidene fluoride to deionized water in a certain mass ratio, stir until completely dissolved, prepare an adhesive solution and age at room temperature for later use; 5) Catalyst compounding and molding calcination: According to the weight percentage, the high-temperature resistant binder solution is added to the reaction vessel, and the modified attapulgite-clinoptilolite composite carrier is added. The carrier is fully wetted by constant temperature stirring. Then, the manganese / cerium / bismuth / lanthanum quaternary composite metal oxide precursor and tungsten-ytterbium composite additive are added. Stirring is continued to form a uniform slurry. The temperature is raised and stirred until the water is completely evaporated to obtain the catalyst precursor. The catalyst precursor is placed in a microwave reactor and calcined in stages under a nitrogen atmosphere. After cooling, it is ground and sieved to obtain the high-activity VOCs waste gas treatment composite catalyst.
[0008] As a further description of the above technical solution: In step 1), the total metal ion concentration of the mixed salt solution is 0.4-0.9 mol / L; the composite complexing agent is a mixture of citric acid and tartaric acid, with a mass ratio of citric acid to tartaric acid of (3-4):1, and a molar ratio of the composite complexing agent to the total metal ions in the mixed salt solution of (0.8-1.3):1; the stirring time at room temperature is 1-2 h; the water bath aging temperature is 75-85℃, and the aging time is 3-5 h; the drying temperature is 105-110℃, and the drying time is 8-12 h.
[0009] As a further description of the above technical solution: In step 2), the concentration of the hydrochloric acid solution for acid activation treatment is 1.0-1.5 mol / L, the liquid-to-solid ratio is (10-15):1 mL / g, the activation temperature is 80-90℃, and the constant temperature stirring activation time is 2-4 h; the silane coupling agent is at least one of γ-aminopropyltriethoxysilane and γ-methacryloyloxypropyltrimethoxysilane; the modified solution is a 95% ethanol aqueous solution of the silane coupling agent by volume, with a mass fraction of 3-6%, the pH is adjusted to 4.0-5.0 using glacial acetic acid, the hydrolysis temperature is 40-50℃, and the hydrolysis time is 15-30 min; the liquid-to-solid ratio for graft modification is (8-12):1 mL / g, the modification temperature is 60-70℃, and the constant temperature stirring time is 2-3 h; calcination is carried out under a nitrogen atmosphere, the calcination temperature is 280-320℃, and the calcination time is 1-2 h.
[0010] As a further description of the above technical solution: In step 3), the amount of polyethylene glycol added is 5-8% of the total mass of tungsten nitrate and ytterbium nitrate; after adjusting the pH to 7.0-7.5, the precipitation time is 1-2 hours; calcination is carried out in an air atmosphere at a temperature of 500-550℃ for 3-4 hours; and the mixture is then ground and passed through a 200-mesh sieve.
[0011] As a further description of the above technical solution: In step 4), the solid content of the adhesive solution is 10-15%, and the aging time at room temperature is 1-2 hours.
[0012] As a further description of the above technical solution: In step 5), the constant temperature stirring temperature for carrier impregnation is 50-60℃, and the stirring time is 1-2h; the stirring time after adding active components and additives is 2-3h; the temperature for heating and evaporation is 95-105℃; the microwave segmented calcination process is as follows: first, pre-calcining at 220-260℃ with microwave power of 300-400W for 1-1.5h, then calcining at 420-480℃ with microwave power of 500-600W for 2-4h; after cooling, grinding through a 100-200 mesh sieve.
[0013] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. In this invention, a manganese / cerium / bismuth / lanthanum quaternary composite metal oxide is used as the core active component. The quaternary components form a strong synergistic effect: manganese oxide provides core oxidation active sites to achieve deep oxidation of VOCs; cerium oxide constructs an efficient oxygen storage-release system, improving oxygen vacancy content and redox performance; bismuth oxide precisely regulates the acidic sites on the catalyst surface, promoting the C-Cl bond breaking and dechlorination process of chlorine-containing VOCs and inhibiting the formation of polychlorinated byproducts; lanthanum oxide stabilizes the crystal structure of the active components, inhibiting chlorine poisoning and loss of active components. Combined with the synergistic effect of tungsten-ytterbium composite additives, the catalyst exhibits extremely low T99 for conventional VOCs such as benzene, toluene, and formaldehyde, as well as chlorine-containing VOCs such as dichloromethane and trichloroethylene, far superior to conventional non-precious metal catalysts, achieving broad-spectrum and efficient degradation at low temperatures.
[0014] 2. In this invention, an attapulgite-clinoptilolite composite carrier is used, combined with a two-step modification process of acid activation and silane coupling agent: the one-dimensional nanopores of attapulgite and the three-dimensional porous structure of clinoptilolite synergistically increase the specific surface area and pore volume of the carrier, enhancing its adsorption and enrichment capacity for VOCs; acid activation etches impurities on the carrier surface, enriches the mesoporous structure, and regulates the acidic sites on the surface; silane coupling agent modification optimizes the hydrophobicity of the carrier surface, enhances the interfacial bonding force with the active components, and prevents the aggregation and loss of active components. The composite carrier achieves a synergistic effect of "adsorption and enrichment - in-situ catalytic degradation," further improving the degradation efficiency of low-concentration VOCs.
[0015] 3. In this invention, an anti-poisoning protection system is constructed through the synergistic regulation of multiple components including bismuth, lanthanum, tungsten, and ytterbium: the rare earth elements lanthanum and ytterbium can inhibit the adsorption of chlorine species at active sites, solving the chlorine poisoning problem during the degradation of chlorine-containing VOCs; tungsten oxide optimizes the acidity of the catalyst surface, promotes the gasification of carbon deposit precursors, and inhibits the formation of surface carbon; simultaneously, the strong interfacial interaction between the modified support and the active components, combined with the molding effect of the high-temperature resistant binder, avoids the sintering and loss of active components under high-temperature conditions. Under complex industrial conditions containing water, sulfur, and chlorine, the catalyst exhibits no significant attenuation of catalytic performance after continuous operation for over 3000 hours, demonstrating stability far exceeding that of existing non-precious metal catalysts.
[0016] 4. In this invention, by completely eliminating the use of precious metals such as platinum and palladium, all raw materials are common non-precious metals and minerals. The raw materials are readily available and inexpensive, which greatly reduces the preparation cost of the catalyst. The preparation process adopts in-situ sol-gel loading combined with microwave segmented calcination. Compared with the traditional process, microwave calcination has uniform heating, fast heating rate, and significantly shortened calcination time. It also has lower energy consumption and can refine the active component grains and increase the oxygen vacancy content. The process has strong controllability, does not require complex equipment, and can achieve large-scale continuous production.
[0017] 5. In this invention, the composite catalyst can be adapted to the treatment of VOCs waste gas in multiple industries such as coating, printing, chemical, and pharmaceutical. It has excellent degradation effect on low-concentration, large-volume, and multi-component complex VOCs waste gas. The degradation products are only CO2, H2O and inorganic chlorides, with no polychlorinated by-products or toxic and harmful substances generated, and no risk of secondary pollution, which meets the requirements of green and environmentally friendly treatment. Attached Figure Description
[0018] Figure 1 This is a flowchart of a method for preparing a highly active composite catalyst for VOCs waste gas treatment. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0020] In the following examples, attapulgite was purchased from Xuyi Zhongtai Mining Co., Ltd., clinoptilolite was purchased from Lingshou Hengzhan Mineral Products Processing Plant, amino-modified silica sol was purchased from Shandong Baite New Materials Co., Ltd., and all other reagents were commercially available analytical grade. All raw materials were available through commercial channels.
[0021] S01: Preparation of precursors for manganese / cerium / bismuth / lanthanum quaternary composite metal oxides 0.1 mol of 50% manganese nitrate solution, 0.08 mol of cerium nitrate, 0.04 mol of bismuth nitrate, and 0.03 mol of lanthanum nitrate were added to 200 mL of deionized water and stirred to prepare a mixed salt solution with a total metal ion concentration of 0.75 mol / L. A composite complexing agent (citric acid to tartaric acid mass ratio 3.5:1) was added to the mixed salt solution, with a molar ratio of composite complexing agent to total metal ions of 1.1:1. After stirring at room temperature for 1.5 h, the pH of the solution was adjusted to 8.5 with ammonia water to form a homogeneous sol. The sol was aged in a water bath at 80 °C for 4 h and dried at 108 °C for 10 h to obtain a manganese / cerium / bismuth / lanthanum quaternary composite metal oxide precursor.
[0022] S02: Preparation of modified attapulgite-clinoptilolite composite carrier Mix 300g of attapulgite and 600g of clinoptilolite evenly, add to 13.5L of 1.2mol / L hydrochloric acid solution, stir and activate at 85℃ for 3h, filter, wash with deionized water until neutral, dry at 110℃, grind through a 200-mesh sieve to obtain acid-activated composite carrier. Add 45g of γ-aminopropyltriethoxysilane to 900mL of 95% ethanol aqueous solution to prepare a 5% modified solution. Adjust the pH to 4.5 with glacial acetic acid and stir at 45℃ for 20min for hydrolysis. 900g of acid-activated composite carrier was added to the modification solution at a liquid-to-solid ratio of 10:1mL / g. The mixture was stirred at 65℃ for 2.5h, filtered, washed three times with anhydrous ethanol, dried at 105℃ to constant weight, and calcined at 300℃ for 1.5h under a nitrogen atmosphere to obtain the modified attapulgite-clinoptilolite composite carrier.
[0023] S03: Preparation of tungsten-ytterbium composite additives Tungsten nitrate and ytterbium nitrate were dissolved in deionized water at a mass ratio of 1.5:1. Polyethylene glycol 6000 (6% of the total mass of the mixed salt) was added, and the mixture was stirred evenly. The pH was adjusted to 7.0 with ammonium bicarbonate solution, and the mixture was allowed to precipitate for 2 hours. The mixture was then filtered, dried at 105°C, calcined at 500°C in air for 3 hours, and ground through a 200-mesh sieve to obtain a tungsten-ytterbium composite additive with a mass ratio of tungsten trioxide to ytterbium oxide of 1.5:1.
[0024] S04: Preparation of high-temperature resistant adhesives Amino-modified silica sol and polyvinylidene fluoride were added to deionized water at a mass ratio of 4:1 and stirred until completely dissolved to prepare an adhesive solution with a solid content of 12%. The solution was then aged at room temperature for 1 hour for later use.
[0025] S05: Catalyst compounding and molding calcination Example 1 By weight percentage, take 1.2% high-temperature resistant binder, 90% modified attapulgite-clinoptilolite composite carrier, 6% manganese / cerium / bismuth / lanthanum quaternary composite metal oxide, and 2.8% tungsten-ytterbium composite additive; A high-temperature resistant binder solution was added to a reactor, followed by a modified attapulgite-clinoptilolite composite carrier. The mixture was stirred at 55°C for 1.5 hours to fully impregnate the carrier. Subsequently, a quaternary composite metal oxide precursor and a tungsten-ytterbium composite additive were added, and the mixture was stirred for another 2.5 hours to form a homogeneous slurry. The slurry was then heated to 100°C and stirred until all moisture was evaporated to obtain a catalyst precursor. The catalyst precursor was placed in a microwave reactor and pre-calcined at 240°C for 1.2 hours under a nitrogen atmosphere using a power of 350W, followed by calcination at 450°C for 3 hours using a power of 550W. After cooling, the catalyst was ground through a 150-mesh sieve to obtain a highly active composite catalyst for VOCs waste gas treatment.
[0026] Example 2 By weight percentage, the following components are included: 1.8% high-temperature resistant binder, 82% modified attapulgite-clinoptilolite composite carrier, 12% manganese / cerium / bismuth / lanthanum quaternary composite metal oxide, and 4.2% tungsten-ytterbium composite additive. The preparation process is the same as in Example 1. The microwave calcination process is as follows: pre-calcination at 250°C with 320W power for 1 hour, and calcination at 460°C with 580W power for 2.5 hours to obtain a highly active composite catalyst for VOCs waste gas treatment.
[0027] Example 3 By weight percentage, the following components are included: 2.2% high-temperature resistant binder, 72% modified attapulgite-clinoptilolite composite carrier, 20% manganese / cerium / bismuth / lanthanum quaternary composite metal oxide, and 5.8% tungsten-ytterbium composite additive. The preparation process is the same as in Example 1. The microwave calcination process is as follows: pre-calcination at 230°C with 380W power for 1.5 hours, and calcination at 430°C with 520W power for 4 hours to obtain a highly active composite catalyst for VOCs waste gas treatment.
[0028] Comparative Example 1 The difference from Example 2 is that the active component is a manganese / cerium / lanthanum ternary composite metal oxide (the bismuth component is removed, and the molar ratio of manganese, cerium and lanthanum remains unchanged), while the other components, contents and preparation process are exactly the same.
[0029] Comparative Example 2 The difference from Example 2 is that the carrier is unmodified pure clinoptilolite, without attapulgite composite, and without acid activation and silane coupling agent modification. The other components, contents and preparation process are exactly the same.
[0030] Comparative Example 3 The difference from Example 2 is that only ytterbium oxide is used as the additive, without tungsten trioxide compound, while the other components, contents and preparation process are exactly the same.
[0031] Comparative Example 4 The difference from Example 2 is that traditional muffle furnace calcination is used instead of microwave segmented calcination. The calcination process is pre-calcination at 240°C for 1.2 hours and calcination at 450°C for 6 hours under a nitrogen atmosphere. The remaining components, contents and preparation processes are exactly the same.
[0032] Performance testing The catalytic performance of the composite catalysts prepared in Examples 1-3 and Comparative Examples 1-4 was tested using the following methods: T99 Test: 0.3g of catalyst was charged into a fixed-bed programmed temperature reactor, and single-component VOCs gases with a concentration of 1000ppm, including benzene, toluene, formaldehyde, dichloromethane, and trichloroethylene, were introduced at a gas hourly space velocity of 30000h⁻¹. -1 The temperature of the reaction bed is monitored in real time by thermocouples, and the concentration of inlet and outlet gases is analyzed online by gas chromatograph. The lowest reaction temperature at which the VOCs conversion rate reaches 99% is recorded, which is T99.
[0033] Stability test: 0.3g of the catalyst from Example 2 was loaded into a fixed-bed reactor, and a mixture of VOCs gas (200ppm each of benzene, toluene, formaldehyde, dichloromethane, and trichloroethylene, with a total concentration of 1000ppm) was introduced. At the same time, 5% water vapor and 10ppm SO2 were added. The reaction temperature was set to the T99 temperature of the mixed gas in Example 2. The reactor was run continuously for 3000h, and the VOCs degradation efficiency was tested every 24h. The degradation efficiency retention rate after 3000h was calculated.
[0034] Byproduct detection: The content of polychlorinated byproducts in the outlet gas was detected by gas chromatography-mass spectrometry at the T99 reaction temperature of dichloromethane.
[0035] The test results are shown in Tables 1 and 2: Table 1. T99 test results (°C) for different catalysts against different VOCs.
[0036] Table 2. Results of stability and byproduct tests
[0037] Test Result Analysis As can be seen from Table 1, the composite catalysts of Examples 1-3 have extremely low T99 values for both conventional VOCs and chlorine-containing VOCs. Among them, Example 2 has the best overall performance, with a T99 of 220°C for benzene and 235°C for dichloromethane, which is far superior to Comparative Examples 1-4. This fully demonstrates that the quaternary active component, modified composite carrier, tungsten-ytterbium composite additive, and microwave calcination process of the present invention have a strong synergistic effect.
[0038] Comparative Example 1, with the removal of the bismuth component, showed a significant increase in the T99 of the catalyst for chlorinated VOCs, demonstrating that the bismuth component is the core element for achieving efficient degradation of chlorinated VOCs and promoting C-Cl bond breaking, thus solving the problem of insufficient activity of conventional catalysts for chlorinated VOCs degradation. Comparative Example 2, using an unmodified pure zeolite support, showed a significant increase in the T99 of the catalyst for all VOCs, demonstrating that the adsorption and enrichment effect and interfacial bonding of the modified composite support are crucial for improving catalytic activity. Comparative Example 3, using a single additive, showed a decrease in both the low-temperature activity and the degradation performance of chlorinated VOCs, demonstrating that the synergistic effect of the tungsten-ytterbium composite additive can further improve the redox performance and anti-poisoning ability of the catalyst. Comparative Example 4, using conventional muffle furnace calcination, showed lower catalyst activity than in Example 2, demonstrating that microwave segmented calcination can refine the active component grains, increase the oxygen vacancy content, and enhance catalytic activity.
[0039] As can be seen from Table 2, the composite catalyst of the present invention can maintain a degradation efficiency of up to 97.2% after 3000 hours of continuous operation under complex conditions containing water, sulfur, and chlorine. There is no pulverization, carbon buildup, or agglomeration. Furthermore, no polychlorinated byproducts are generated during the degradation of dichloromethane. This fully demonstrates that the catalyst has excellent anti-poisoning and anti-carbon buildup properties and long-term stability, with no risk of secondary pollution.
[0040] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A highly active composite catalyst for treating VOCs waste gas, characterized in that, It is composed of the following components by weight percentage: 3-22% manganese / cerium / bismuth / lanthanum quaternary composite metal oxide, 70-92% modified attapulgite-clinoptilolite composite carrier, 2-7% tungsten-ytterbium composite additive, and 0.8-2.5% high-temperature resistant binder; In the manganese / cerium / bismuth / lanthanum quaternary composite metal oxide, the molar ratio of manganese, cerium, bismuth, and lanthanum is 1:(0.6-1.0):(0.3-0.6):(0.2-0.4). In the modified attapulgite-clinoplastite composite carrier, the mass ratio of attapulgite to clinoplastite is (2-4):6; The tungsten-ytterbium composite additive is a mixture of tungsten trioxide and ytterbium oxide, with a mass ratio of tungsten trioxide to ytterbium oxide of (1-2):
1.
2. The highly active composite catalyst for VOCs waste gas treatment according to claim 1, characterized in that, The high-temperature resistant adhesive is a compound of amino-modified silica sol and polyvinylidene fluoride, with a mass ratio of amino-modified silica sol to polyvinylidene fluoride of (3-5):
1.
3. A method for preparing a highly active composite catalyst for VOCs waste gas treatment as described in any one of claims 1-2, characterized in that, Includes the following steps: 1) Preparation of manganese / cerium / bismuth / lanthanum quaternary composite metal oxide precursor: 50% manganese nitrate solution, cerium nitrate, bismuth nitrate, and lanthanum nitrate were added to deionized water at the target molar ratio and stirred to prepare a mixed salt solution; a composite complexing agent was added to the mixed salt solution, and after stirring at room temperature, the pH was adjusted to 8.0-9.0 with ammonia water to form a homogeneous sol; after water bath aging and drying, the manganese / cerium / bismuth / lanthanum quaternary composite metal oxide precursor was obtained. 2) Preparation of modified attapulgite-clinoptilolite composite carrier: Attapulgite and clinoptilolite were mixed in a mass ratio, and after acid activation treatment with hydrochloric acid solution, the mixture was washed, dried, and sieved to obtain an acid-activated composite carrier; a silane coupling agent was prepared into a modification solution and hydrolyzed, and then the acid-activated composite carrier was added to the modification solution for graft modification. After washing, drying, and calcination, the modified attapulgite-clinoptilolite composite carrier was obtained. 3) Preparation of tungsten-ytterbium composite additive: Dissolve tungsten nitrate and ytterbium nitrate in deionized water at the target mass ratio, add polyethylene glycol dispersant, stir evenly, adjust the pH to neutral with ammonium bicarbonate solution, and obtain tungsten-ytterbium composite additive after precipitation, filtration, drying, calcination, grinding and sieving. 4) Preparation of high-temperature resistant adhesive solution: Add amino-modified silica sol and polyvinylidene fluoride to deionized water in a certain mass ratio, stir until completely dissolved, prepare an adhesive solution and age at room temperature for later use; 5) Catalyst compounding and molding calcination: According to the weight percentage, the high-temperature resistant binder solution is added to the reaction vessel, and the modified attapulgite-clinoptilolite composite carrier is added. The carrier is fully wetted by constant temperature stirring. Then, the manganese / cerium / bismuth / lanthanum quaternary composite metal oxide precursor and tungsten-ytterbium composite additive are added. Stirring is continued to form a uniform slurry. The temperature is raised and stirred until the water is completely evaporated to obtain the catalyst precursor. The catalyst precursor is placed in a microwave reactor and calcined in stages under a nitrogen atmosphere. After cooling, it is ground and sieved to obtain the high-activity VOCs waste gas treatment composite catalyst.
4. The method for preparing a highly active composite catalyst for VOCs waste gas treatment according to claim 3, characterized in that, In step 1), the total metal ion concentration of the mixed salt solution is 0.4-0.9 mol / L; the composite complexing agent is a mixture of citric acid and tartaric acid, with a mass ratio of citric acid to tartaric acid of (3-4):1, and a molar ratio of the composite complexing agent to the total metal ions in the mixed salt solution of (0.8-1.3):1; the stirring time at room temperature is 1-2 h; the water bath aging temperature is 75-85℃, and the aging time is 3-5 h; the drying temperature is 105-110℃, and the drying time is 8-12 h.
5. The method for preparing a highly active composite catalyst for VOCs waste gas treatment according to claim 3, characterized in that, In step 2), the concentration of the hydrochloric acid solution for acid activation treatment is 1.0-1.5 mol / L, the liquid-to-solid ratio is (10-15):1 mL / g, the activation temperature is 80-90℃, and the constant temperature stirring activation time is 2-4 h; the silane coupling agent is at least one of γ-aminopropyltriethoxysilane and γ-methacryloyloxypropyltrimethoxysilane; the modified solution is a 95% ethanol aqueous solution of the silane coupling agent by volume, with a mass fraction of 3-6%, the pH is adjusted to 4.0-5.0 using glacial acetic acid, the hydrolysis temperature is 40-50℃, and the hydrolysis time is 15-30 min; the liquid-to-solid ratio for graft modification is (8-12):1 mL / g, the modification temperature is 60-70℃, and the constant temperature stirring time is 2-3 h; calcination is carried out under a nitrogen atmosphere, the calcination temperature is 280-320℃, and the calcination time is 1-2 h.
6. The method for preparing a highly active composite catalyst for VOCs waste gas treatment according to claim 3, characterized in that, In step 3), the amount of polyethylene glycol added is 5-8% of the total mass of tungsten nitrate and ytterbium nitrate; after adjusting the pH to 7.0-7.5, the precipitation time is 1-2 hours; calcination is carried out in an air atmosphere at a temperature of 500-550℃ for 3-4 hours; and the mixture is then ground and passed through a 200-mesh sieve.
7. The method for preparing a highly active composite catalyst for VOCs waste gas treatment according to claim 3, characterized in that, In step 4), the solid content of the adhesive solution is 10-15%, and the aging time at room temperature is 1-2 hours.
8. The method for preparing a highly active composite catalyst for VOCs waste gas treatment according to claim 3, characterized in that, In step 5), the constant temperature stirring temperature for carrier impregnation is 50-60℃, and the stirring time is 1-2h; the stirring time after adding active components and additives is 2-3h; the temperature for heating and evaporation is 95-105℃; the microwave segmented calcination process is as follows: first, pre-calcining at 220-260℃ with microwave power of 300-400W for 1-1.5h, then calcining at 420-480℃ with microwave power of 500-600W for 2-4h; after cooling, grinding through a 100-200 mesh sieve.