Composite metal catalyst for catalytic degradation of vocs at low temperature and preparation method thereof
By leveraging the synergistic effect of copper/manganese/cerium/zirconium quaternary composite metal oxides and modified mesoporous zeolite, the high cost of precious metals and insufficient low-temperature activity of existing VOCs catalytic catalysts are solved, achieving efficient low-temperature catalytic degradation of VOCs, which is suitable for industrial waste gas treatment in multiple industries.
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 the following problems: precious metal resources are scarce and expensive, resulting in high preparation costs and easy poisoning and deactivation; non-precious metal catalysts have insufficient low-temperature catalytic activity, high T99 temperature, poor carrier binding, low stability and service life, and the preparation process leads to poor dispersion of active components and weak water and sulfur resistance.
A catalyst was prepared by complexation precipitation using a copper/manganese/cerium/zirconium quaternary composite metal oxide as the active component, modified mesoporous zeolite as the carrier, a compound of alkaline earth metal and rare earth metal oxides as an auxiliary agent, and a compound of silica-alumina sol and modified sodium alginate as a binder, to achieve uniform dispersion and high bonding strength of the active component.
It significantly reduces the oxidation and decomposition temperature of VOCs, improves catalytic degradation efficiency and catalyst thermal stability, is suitable for large-scale industrial applications, has high degradation efficiency, and is applicable to the treatment of various VOCs waste gases.
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Figure CN122141744A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of environmental catalysis technology, and in particular relates to a composite metal catalyst for low-temperature catalytic degradation of VOCs and its preparation method. Background Technology
[0002] Volatile organic compounds (VOCs) are among the major air pollutants, encompassing a variety of substances such as aromatic hydrocarbons, aldehydes, ketones, esters, and ethers. They easily cause environmental problems such as photochemical smog and haze, seriously threatening the ecological environment and human health. Catalytic combustion, which can oxidize and decompose VOCs into non-toxic CO2 and H2O at relatively low temperatures, has become the mainstream technology for end-of-pipe treatment of low-concentration VOCs. The core technology is a high-performance catalytic catalyst.
[0003] Existing VOCs catalytic catalysts mainly suffer from two types of problems: First, catalysts using precious metals such as platinum, palladium, and rhodium as active components, although exhibiting good low-temperature activity, suffer from the scarcity and high cost of precious metal resources, resulting in high preparation costs. Furthermore, they are susceptible to poisoning and deactivation by impurities in flue gas, making large-scale industrial application difficult. Second, non-precious metal catalysts mostly use single or binary metal oxides as active components, which suffer from insufficient low-temperature catalytic activity, a high T99 (99% conversion temperature of pollutants), and low degradation efficiency for low-concentration VOCs. At the same time, traditional catalyst supports are mostly ordinary zeolites, alumina, etc., which have limited adsorption capacity for VOCs. The poor binding between the active component and the support makes them prone to aggregation, leading to reduced catalyst stability and service life.
[0004] In addition, the existing preparation processes of non-precious metal catalysts are mostly simple mechanical mixing or impregnation methods. The active components are poorly dispersed on the carrier surface, which cannot fully exert their catalytic effect. Furthermore, the catalysts have weak resistance to water and sulfur, and their catalytic performance decays rapidly under the complex working conditions of actual industrial waste gas. Summary of the Invention
[0005] The purpose of this invention is to provide a composite metal catalyst for low-temperature catalytic degradation of VOCs and its preparation method in order to solve the above-mentioned problems.
[0006] On the one hand, in order to achieve the above objectives, the present invention adopts the following technical solution: a composite metal catalyst for low-temperature catalytic degradation of VOCs, wherein the composite metal catalyst comprises the following components by weight percentage: 5-25% multi-component composite metal oxide, 65-90% modified mesoporous zeolite, 2-6% composite additives, and 1-3% high-temperature resistant binder; The multi-component composite metal oxide is a copper / manganese / cerium / zirconium quaternary composite oxide, with the molar ratio of copper, manganese, cerium, and zirconium being 1:(0.8-1.2):(0.5-0.8):(0.2-0.5). The modified mesoporous zeolite is ZSM-5 mesoporous zeolite that has been synergistically modified with rare earth ions and amphoteric surfactants. The composite additive is a mixture of alkaline earth metal oxides and rare earth metal oxides. The high-temperature resistant binder is a compound of silica-alumina sol and modified sodium alginate.
[0007] As a further description of the above technical solution: The rare earth ion is La. 3+ Ce 3+ At least one of the following, wherein the amphoteric surfactant is at least one of dodecyl dimethyl betaine and cocamidopropyl betaine.
[0008] As a further description of the above technical solution: In the composite additive, the alkaline earth metal oxide is at least one of calcium oxide, magnesium oxide, and barium oxide, and the rare earth metal oxide is at least one of lanthanum oxide, neodymium oxide, and yttrium oxide. The mass ratio of alkaline earth metal oxide to rare earth metal oxide is (1-3):1.
[0009] As a further description of the above technical solution: In the high-temperature resistant adhesive, the mass ratio of silica-alumina sol to modified sodium alginate is (4-6):1; the modified sodium alginate is phosphorylated sodium alginate with a degree of phosphorylation substitution of 0.3-0.5.
[0010] On the other hand, in order to achieve the above objectives, the present invention employs the following method: a method for preparing a composite metal catalyst for low-temperature catalytic degradation of VOCs, comprising the following steps: 1) Preparation of multi-component composite metal oxides: Copper nitrate, manganese nitrate, cerium nitrate and zirconium nitrate were dissolved in deionized water in proportion to prepare a mixed salt solution. After adding a complexing agent and stirring at room temperature, the pH was adjusted to 8.5-9.5 with ammonia water to form a gel. After water bath aging, drying, calcination, grinding and sieving, copper / manganese / cerium / zirconium quaternary composite metal oxides were obtained. 2) Preparation of modified mesoporous zeolite: ZSM-5 mesoporous zeolite was modified by impregnation with rare earth ion nitrate solution to obtain rare earth ion modified zeolite, which was then added to an ethanol aqueous solution of amphoteric surfactant and stirred at a constant temperature. After washing, drying and calcination, modified mesoporous zeolite was obtained. 3) Preparation of composite additives: Alkaline earth metal nitrates and rare earth metal nitrates are dissolved in deionized water in a certain proportion, polyethylene glycol dispersant is added, and the pH is adjusted to 7.0-7.5 with ammonium bicarbonate solution to precipitate. After filtration, drying, calcination, grinding and sieving, the composite additives are obtained. 4) Preparation of high-temperature resistant adhesive: Add silica-alumina sol and phosphorylated modified sodium alginate to deionized water in proportion and stir to dissolve, prepare an adhesive solution and age at room temperature to obtain a high-temperature resistant adhesive; 5) Catalyst compounding and calcination: High-temperature resistant binder, modified mesoporous zeolite, multi-component composite metal oxide and composite additive are mixed sequentially according to weight percentage. After stirring and heating to evaporate water, a catalyst precursor is obtained. Then, after pre-calcination, high-temperature calcination, cooling, grinding and sieving, the composite metal catalyst for low-temperature catalytic degradation of VOCs is obtained.
[0011] As a further description of the above technical solution: In step 1), the total metal ion concentration of the mixed salt solution is 0.5-1.0 mol / L; the complexing agent is a compound of citric acid and disodium ethylenediaminetetraacetate, with a mass ratio of citric acid to disodium ethylenediaminetetraacetate of (2-3):1, and a molar ratio of complexing agent to total metal ions of (1.0-1.5):1.
[0012] As a further description of the above technical solution: In step 1), the water bath aging temperature is 80-90℃ and the aging time is 4-6h; the drying temperature is 105-115℃ and the drying time is 10-12h; the calcination is carried out in an air atmosphere, the calcination temperature is 450-550℃ and the calcination time is 4-6h; and the material is ground through a 200-mesh sieve.
[0013] As a further description of the above technical solution: In step 2), the rare earth ion concentration of the rare earth ion nitrate solution is 0.1-0.3 mol / L, the liquid-to-solid ratio is (8-12):1 mL / g, the impregnation temperature is 50-60℃, and the impregnation time is 2-4 h; the mass fraction of the ethanol aqueous solution of the amphoteric surfactant is 30-40%, the concentration is 0.05-0.1 mol / L, and the dissolution temperature is 40-50℃; the liquid-to-solid ratio of the rare earth ion modified zeolite to the surfactant solution is (10-15):1 mL / g, the constant temperature stirring temperature is 60-70℃, and the stirring time is 3-5 h; calcination is carried out under a nitrogen atmosphere, the calcination temperature is 300-350℃, and the calcination time is 2-3 h.
[0014] 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 the mixed salt; after adjusting the precipitation with ammonium bicarbonate solution, the precipitation time is 1-2 hours; calcination is carried out in an air atmosphere at a calcination temperature of 500-550℃ for 3-4 hours; and the mixture is ground through a 200-mesh sieve; in step 4), the solid content of the high-temperature resistant adhesive solution is 10-15%, and the aging time at room temperature is 1-2 hours.
[0015] As a further description of the above technical solution: In step 5), the stirring temperature for mixing the modified mesoporous zeolite with the high-temperature resistant binder solution is 50-60℃, and the stirring time is 1-2 hours; after adding the multi-component composite metal oxide and composite additives, stirring continues for 2-3 hours; the temperature for heating and evaporation is 95-105℃; pre-calcination is carried out under a nitrogen atmosphere at a temperature of 200-250℃ for 1-2 hours; high-temperature calcination is carried out under a nitrogen atmosphere at a temperature of 400-480℃ for 5-7 hours; after cooling, it is ground through a 100-200 mesh sieve.
[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. In this invention, a copper / manganese / cerium / zirconium quaternary composite metal oxide is used as the active component. The introduction of cerium and zirconium forms a solid solution structure, which greatly improves the oxygen storage capacity and redox performance of the active component. The synergistic effect of copper and manganese with cerium and zirconium significantly reduces the oxidation decomposition temperature of VOCs. ZSM-5 mesoporous zeolite, which is synergistically modified with rare earth ions and amphoteric surfactants, not only retains the large specific surface area and pore volume of mesoporous zeolite, but also improves the physical adsorption capacity of VOCs through modification, realizing the synergistic effect of adsorption enrichment and low-temperature catalysis. This makes the T99 of the catalyst for common VOCs such as benzene, toluene, ethyl acetate, and formaldehyde as low as 160-260℃, and the low-temperature degradation efficiency is far superior to that of existing non-precious metal catalysts.
[0017] 2. In this invention, the active components, carrier modifiers, and additives are all non-precious metal raw materials, eliminating the use of precious metals such as platinum and palladium, which greatly reduces the preparation cost of the catalyst and is suitable for large-scale industrial production and application.
[0018] 3. In this invention, a complex precipitation method is used to prepare multi-component composite metal oxides. Combined with the synergistic modification of the carrier and the compounding of the binder, the active components are uniformly dispersed on the surface and in the pores of the carrier, avoiding the agglomeration of the active components. At the same time, the introduction of high-temperature resistant binder improves the bonding strength between the active components and the carrier. The compounded additives of rare earth elements and alkaline earth metals further enhance the thermal stability and water and sulfur resistance of the catalyst. Under the complex working conditions of actual industrial waste gas, the catalyst shows no significant attenuation of catalytic performance after continuous use for more than 3000 hours.
[0019] 4. In this invention, the preparation process is all conventional chemical operation, without the need for complex equipment. The parameters of each step are controllable, the dispersibility of the active components and the formability of the catalyst are easily controlled, and large-scale continuous production can be achieved. Moreover, no toxic or harmful by-products are generated during the preparation process, which is in line with the green and environmentally friendly production concept.
[0020] 5. In this invention, the composite metal catalyst has excellent degradation effect on low concentration (500-2000ppm) and various types of VOCs waste gas, and can be applied to the treatment of VOCs waste gas in multiple industries such as coating, printing, chemical, and pharmaceutical, with broad application prospects. Attached Figure Description
[0021] Figure 1 This is a flowchart of a method for preparing a composite metal catalyst for low-temperature catalytic degradation of VOCs. Detailed Implementation
[0022] 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.
[0023] In the following examples, ZSM-5 mesoporous zeolite was purchased from Nanjing Shundajie Chemical Technology Co., Ltd., silica-alumina sol was purchased from Zibo Yinghe Chemical Co., Ltd., phosphorylated modified sodium alginate (degree of substitution 0.4) was prepared in-house, and all other reagents were commercially available analytical grade.
[0024] S01: Preparation of multi-component composite metal oxides Copper nitrate, manganese nitrate, cerium nitrate, and zirconium nitrate were dissolved in deionized water in a molar ratio of 1:1:0.6:0.3 to prepare a mixed salt solution with a total metal ion concentration of 0.8 mol / L. A complexing agent of citric acid and disodium ethylenediaminetetraacetate (mass ratio 2.5:1) was added, with a molar ratio of complexing agent to total metal ions of 1.2:1. The mixture was stirred at room temperature for 1.5 h, and the pH was adjusted to 9.0 with ammonia water to form a gel. The gel was aged in a water bath at 85°C for 5 h, dried at 110°C for 11 h, calcined at 500°C in air for 5 h, and ground through a 200-mesh sieve to obtain a copper / manganese / cerium / zirconium quaternary composite metal oxide. S02: Preparation of modified mesoporous zeolite ZSM-5 mesoporous zeolite was added to a 0.2 mol / L La(NO3)3 solution at a liquid-to-solid ratio of 10:1 mL / g, stirred and impregnated at 55°C for 3 h, filtered, and dried at 105°C to obtain lanthanum-modified zeolite. Dodecyl dimethyl betaine was dissolved in a 35% aqueous ethanol solution to prepare a 0.08 mol / L solution, and stirred at 45°C until completely dissolved; Lanthanum-modified zeolite was added to the above solution at a liquid-to-solid ratio of 12:1 mL / g, stirred at 65℃ for 4 h, filtered, washed three times with anhydrous ethanol, dried at 85℃ to constant weight, and calcined at 320℃ for 2.5 h under a nitrogen atmosphere to obtain modified mesoporous zeolite. S03: Preparation of composite additives Magnesium nitrate and lanthanum nitrate were dissolved in deionized water at a mass ratio of 2:1. Polyethylene glycol 6000 (6% of the total mass of the mixed salt) was added and stirred evenly. The pH was adjusted to 7.2 with 5% ammonium bicarbonate solution, and the mixture was allowed to precipitate for 1.5 hours. The mixture was then filtered, dried at 105°C, calcined at 520°C in air for 3.5 hours, and ground through a 200-mesh sieve to obtain the magnesium-lanthanum composite additive. S04: Preparation of high-temperature resistant adhesives Add silica-alumina sol and phosphorylated modified sodium alginate to deionized water at a mass ratio of 5:1, stir until completely dissolved, and prepare a binder solution with a solid content of 12%. Let it age at room temperature for 1.5 hours for later use.
[0025] S05: Catalyst Combination and Calcination Example 1 By weight percentage, take 2% high-temperature resistant binder, 88% modified mesoporous zeolite, 8% multi-component composite metal oxide, and 2% composite additives; A high-temperature resistant binder solution was added to a reactor, followed by modified mesoporous zeolite, and stirred at 55°C for 1.5 hours. Multi-component composite metal oxides and composite additives were then added, and stirring continued for 2.5 hours. The temperature was raised to 100°C and stirred until the moisture evaporated to obtain a catalyst precursor. The precursor was pre-calcined at 220°C for 1.5 hours under a nitrogen atmosphere, then calcined at 450°C for 6 hours. After cooling, it was ground through a 150-mesh sieve to obtain a composite metal catalyst.
[0026] Example 2 By weight percentage, take 1.5% high-temperature resistant binder, 82% modified mesoporous zeolite, 14% multi-component composite metal oxide, and 2.5% composite additives; The preparation process was the same as in Example 1, with calcination at 420°C for 5.5 h under a nitrogen atmosphere to obtain the composite metal catalyst.
[0027] Example 3 By weight percentage, take 2.5% high-temperature resistant binder, 68% modified mesoporous zeolite, 23% multi-component composite metal oxide, and 6.5% composite additives; The preparation process was the same as in Example 1, with calcination at 470°C for 6.5 h under a nitrogen atmosphere to obtain the composite metal catalyst.
[0028] Comparative Example 1 The difference from Example 2 is that the active component is a manganese / cobalt binary composite oxide, while the other components and preparation process are the same.
[0029] Comparative Example 2 The difference from Example 2 is that the carrier is unmodified ordinary ZSM-5 zeolite, while the other components and preparation process are the same.
[0030] Comparative Example 3 The difference from Example 2 is that there is no composite additive, but the remaining components and preparation process are the same.
[0031] Performance testing The catalysts prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to T99 and stability tests, and the test methods are as follows: T99 Test: 0.3g of catalyst was placed in a programmed temperature rise furnace, and a VOCs mixed gas (benzene:toluene:ethyl acetate:formaldehyde:ethyl ether = 1:1:1:1:1) with a concentration of 1000ppm was introduced at a space velocity of 30000h⁻¹. -1 The reaction temperature was measured using thermocouples, and the concentration of the outlet gas was analyzed online using gas chromatography. The lowest temperature at which the VOCs conversion rate reached 99% was recorded, i.e., T99.
[0032] Stability test: Under the above test conditions, the reaction temperature was set to the T99 temperature of the catalyst, VOCs mixed gas was continuously introduced and 5% water vapor and 10 ppm SO2 were added. The system was run continuously for 3000 hours, and the retention rate of VOCs degradation efficiency was tested.
[0033] The test results are shown in Tables 1 and 2: Table 1. T99 test results (°C) for each catalyst
[0034] Table 2. Stability test results of each catalyst
[0035] The test results show that: The T99 values of the composite metal catalysts in Examples 1-3 for various VOCs were much lower than those in the comparative example, indicating that the synergistic effect of the copper / manganese / cerium / zirconium quaternary composite metal oxide, modified mesoporous zeolite, and composite additives significantly improved the low-temperature catalytic activity of the catalysts. Comparative Example 1, due to the use of binary metal oxide as the active component, lacks the oxygen storage synergy of cerium and zirconium, resulting in a significant decrease in low-temperature activity; Comparative Example 2, due to the unmodified support, has insufficient adsorption capacity, poor adsorption-catalysis synergy, and a high T99; Comparative Example 3, due to the lack of composite additives, has insufficient redox performance and stability, resulting in a decrease in both low-temperature activity and stability. The catalysts in Examples 1-3 operated continuously for 3000 hours under complex conditions containing moisture and sulfur, and the degradation efficiency remained above 96% without pulverization or agglomeration. This indicates that the catalysts of the present invention have excellent thermal stability, water and sulfur resistance, and structural stability.
[0036] 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 composite metal catalyst for low-temperature catalytic degradation of VOCs, characterized in that, The composite metal catalyst comprises the following components by weight percentage: 5-25% multi-component composite metal oxide, 65-90% modified mesoporous zeolite, 2-6% composite additives, and 1-3% high-temperature resistant binder; The multi-component composite metal oxide is a copper / manganese / cerium / zirconium quaternary composite oxide, with the molar ratio of copper, manganese, cerium, and zirconium being 1:(0.8-1.2):(0.5-0.8):(0.2-0.5). The modified mesoporous zeolite is ZSM-5 mesoporous zeolite that has been synergistically modified with rare earth ions and amphoteric surfactants. The composite additive is a mixture of alkaline earth metal oxides and rare earth metal oxides. The high-temperature resistant binder is a compound of silica-alumina sol and modified sodium alginate.
2. The composite metal catalyst for low-temperature catalytic degradation of VOCs according to claim 1, characterized in that, The rare earth ion is La. 3+ Ce 3+ At least one of the following, wherein the amphoteric surfactant is at least one of dodecyl dimethyl betaine and cocamidopropyl betaine.
3. The composite metal catalyst for low-temperature catalytic degradation of VOCs according to claim 1, characterized in that, In the composite additive, the alkaline earth metal oxide is at least one of calcium oxide, magnesium oxide, and barium oxide, and the rare earth metal oxide is at least one of lanthanum oxide, neodymium oxide, and yttrium oxide. The mass ratio of alkaline earth metal oxide to rare earth metal oxide is (1-3):
1.
4. The composite metal catalyst for low-temperature catalytic degradation of VOCs according to claim 1, characterized in that, In the high-temperature resistant adhesive, the mass ratio of silica-alumina sol to modified sodium alginate is (4-6):1; the modified sodium alginate is phosphorylated sodium alginate with a degree of phosphorylation substitution of 0.3-0.
5.
5. A method for preparing a composite metal catalyst for low-temperature catalytic degradation of VOCs as described in any one of claims 1-4, characterized in that, Includes the following steps: 1) Preparation of multi-component composite metal oxides: Copper nitrate, manganese nitrate, cerium nitrate and zirconium nitrate were dissolved in deionized water in proportion to prepare a mixed salt solution. After adding a complexing agent and stirring at room temperature, the pH was adjusted to 8.5-9.5 with ammonia water to form a gel. After water bath aging, drying, calcination, grinding and sieving, copper / manganese / cerium / zirconium quaternary composite metal oxides were obtained. 2) Preparation of modified mesoporous zeolite: ZSM-5 mesoporous zeolite was modified by impregnation with rare earth ion nitrate solution to obtain rare earth ion modified zeolite, which was then added to an ethanol aqueous solution of amphoteric surfactant and stirred at a constant temperature. After washing, drying and calcination, modified mesoporous zeolite was obtained. 3) Preparation of composite additives: Alkaline earth metal nitrates and rare earth metal nitrates are dissolved in deionized water in a certain proportion, polyethylene glycol dispersant is added, and the pH is adjusted to 7.0-7.5 with ammonium bicarbonate solution to precipitate. After filtration, drying, calcination, grinding and sieving, the composite additives are obtained. 4) Preparation of high-temperature resistant adhesive: Add silica-alumina sol and phosphorylated modified sodium alginate to deionized water in proportion and stir to dissolve, prepare an adhesive solution and age at room temperature to obtain a high-temperature resistant adhesive; 5) Catalyst compounding and calcination: High-temperature resistant binder, modified mesoporous zeolite, multi-component composite metal oxide and composite additive are mixed sequentially according to weight percentage. After stirring and heating to evaporate water, a catalyst precursor is obtained. Then, after pre-calcination, high-temperature calcination, cooling, grinding and sieving, the composite metal catalyst for low-temperature catalytic degradation of VOCs is obtained.
6. The method for preparing a composite metal catalyst for low-temperature catalytic degradation of VOCs according to claim 5, characterized in that, In step 1), the total metal ion concentration of the mixed salt solution is 0.5-1.0 mol / L; the complexing agent is a compound of citric acid and disodium ethylenediaminetetraacetate, with a mass ratio of citric acid to disodium ethylenediaminetetraacetate of (2-3):1, and a molar ratio of complexing agent to total metal ions of (1.0-1.5):
1.
7. The method for preparing a composite metal catalyst for low-temperature catalytic degradation of VOCs according to claim 5, characterized in that, In step 1), the water bath aging temperature is 80-90℃ and the aging time is 4-6h; the drying temperature is 105-115℃ and the drying time is 10-12h; the calcination is carried out in an air atmosphere, the calcination temperature is 450-550℃ and the calcination time is 4-6h; and the material is ground through a 200-mesh sieve.
8. The method for preparing a composite metal catalyst for low-temperature catalytic degradation of VOCs according to claim 5, characterized in that, In step 2), the rare earth ion concentration of the rare earth ion nitrate solution is 0.1-0.3 mol / L, the liquid-to-solid ratio is (8-12):1 mL / g, the impregnation temperature is 50-60℃, and the impregnation time is 2-4 h; the mass fraction of the ethanol aqueous solution of the amphoteric surfactant is 30-40%, the concentration is 0.05-0.1 mol / L, and the dissolution temperature is 40-50℃; the liquid-to-solid ratio of the rare earth ion modified zeolite to the surfactant solution is (10-15):1 mL / g, the constant temperature stirring temperature is 60-70℃, and the stirring time is 3-5 h; calcination is carried out under a nitrogen atmosphere, the calcination temperature is 300-350℃, and the calcination time is 2-3 h.
9. The method for preparing a composite metal catalyst for low-temperature catalytic degradation of VOCs according to claim 5, characterized in that, In step 3), the amount of polyethylene glycol added is 5-8% of the total mass of the mixed salt; after adjusting the precipitation with ammonium bicarbonate solution, the precipitation time is 1-2 hours; calcination is carried out in an air atmosphere at a calcination temperature of 500-550℃ for 3-4 hours; and the mixture is ground through a 200-mesh sieve; in step 4), the solid content of the high-temperature resistant adhesive solution is 10-15%, and the aging time at room temperature is 1-2 hours.
10. The method for preparing a composite metal catalyst for low-temperature catalytic degradation of VOCs according to claim 5, characterized in that, In step 5), the stirring temperature for mixing the modified mesoporous zeolite with the high-temperature resistant binder solution is 50-60℃, and the stirring time is 1-2 hours; after adding the multi-component composite metal oxide and composite additives, stirring continues for 2-3 hours; the temperature for heating and evaporation is 95-105℃; pre-calcination is carried out under a nitrogen atmosphere at a temperature of 200-250℃ for 1-2 hours; high-temperature calcination is carried out under a nitrogen atmosphere at a temperature of 400-480℃ for 5-7 hours; after cooling, it is ground through a 100-200 mesh sieve.