CN114160184B - Preparation method and application of silver-cerium bimetallic molecular sieve catalyst for catalyzing and oxidizing VOCs (volatile organic compounds) in cooperation with ozone - Google Patents

Preparation method and application of silver-cerium bimetallic molecular sieve catalyst for catalyzing and oxidizing VOCs (volatile organic compounds) in cooperation with ozone Download PDF

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CN114160184B
CN114160184B CN202111340275.6A CN202111340275A CN114160184B CN 114160184 B CN114160184 B CN 114160184B CN 202111340275 A CN202111340275 A CN 202111340275A CN 114160184 B CN114160184 B CN 114160184B
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CN114160184A (en
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吴军良
石雪风
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South China University of Technology SCUT
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Abstract

The invention discloses a method for preparing a silver-cerium bimetallic molecular sieve catalyst by pre-synthesizing silver nanoparticles and oxidizing Volatile Organic Compounds (VOCs) in cooperation with ozone catalysis and application thereof. The method comprises the following steps: pre-synthesizing Ag nano particles with uniform size; then, the molecular sieve is used as a carrier, and cerium oxide (CeO) is added by adopting an impregnation method 2 ) Loaded on a molecular sieve to obtain CeO 2 A molecular sieve; finally, ag nano particles are dispersed in CeO by adopting a particle adsorption method 2 On the molecular sieve. According to the method, strong interaction between silver and cerium double metals is firstly utilized to decompose ozone to generate high-activity oxygen species, and meanwhile, the characteristic that the specific surface area of a molecular sieve is large is utilized to effectively disperse silver and cerium double-metal active components and provide a large number of adsorption sites for VOCs, so that the reaction activity of the catalyst in cooperation with ozone to catalyze and oxidize the VOCs is improved.

Description

Preparation method and application of silver-cerium bimetallic molecular sieve catalyst for catalyzing and oxidizing VOCs (volatile organic compounds) in cooperation with ozone
Technical Field
The invention relates to the field of purification of volatile organic compounds, in particular to a method for preparing a silver-cerium bimetallic molecular sieve catalyst by pre-synthesizing silver nanoparticles in cooperation with ozone catalytic oxidation VOCs and application of the silver-cerium bimetallic molecular sieve catalyst.
Background
VOCs is the production of near-surface O 3 And PM 2.5 The important precursors of the compound have direct toxic action on human bodies, and in recent years, along with the large discharge of human-derived VOCs, the compound has very serious influence on the natural environment and the human health.
Currently, most of the emissions of VOCs originate from industry, most of which are characterized by high wind volumes and low concentrations. For the treatment of such exhaust gas, methods such as absorption, adsorption, combustion, and condensation methods are generally used. Absorption and adsorption processes do not destroy the VOCs, but rather transfer the VOCs, and the cost of secondary treatment of the absorption liquid or adsorbent is high. The combustion method (including catalytic combustion method) and the condensation method are suitable for treating high-concentration organic waste gas, and when the method is applied to treating low-concentration waste gas, an adsorption method needs to be combined, so that the investment of the combined technology is large, and the energy consumption for operation is high.
The catalytic ozonation technology developed from the catalytic combustion method can oxidize low-concentration VOCs efficiently at lower temperature (below 120 ℃) and normal pressure, can be used for purifying industrial low-concentration organic waste gas and indoor air, has simple process and high reaction speed, and is a very potential VOCs control technology. Ozone has certain oxidizability, but the oxidation by using ozone only has the defects of low utilization rate, insufficient oxidation capacity, low degradation efficiency and the like. Research shows that the combination of ozone and catalyst can raise the catalytic efficiency by 30-60 times. The reason for this is that after the catalyst is introduced, the catalyst can decompose ozone to form active oxygen species with strong oxidizing property, the oxidation reaction rate of the active oxygen species and the VOCs is higher by several orders of magnitude than that of ozone alone, and the active oxygen species can rapidly and thoroughly oxidize the VOCs adsorbed on the catalyst.
In this technology, a catalyst that works synergistically with ozone is critical. Generally, catalysts are often required to have low commercial cost and excellent performance. A large number of catalysts have been used for the catalytic oxidation of VOCs by ozone, with the vast majority of catalysts having transition metal oxides and noble metals as active components. The research shows that when a catalyst taking transition metal oxide as an active component is used for reaction, the problems of residual organic by-products, incomplete ozone decomposition, low mineralization rate and the like exist, and the research shows that a proper amount of noble metal is added into the transition metal oxide, so that the transition metal oxide and the noble metal can generate interaction, the oxidation-reduction performance and the ozone decomposition performance of the catalyst are improved, the activity of the catalyst is greatly improved, and the problems can be effectively solved. At present, the catalyst with double active components uses expensive elements such as platinum, palladium, rhodium and the like as noble metal components, and even if the use amount of the noble metal is reduced by an optimized preparation method, the catalyst still has the defects of high cost and difficult commercial popularization. Therefore, it is highly desirable to develop a high-efficiency low-cost catalyst. Silver, as a relatively inexpensive precious metal component, can be used in combination with metal oxides to produce the same interaction, and is expected to greatly reduce the production cost of the catalyst.
In view of the above, the invention provides a preparation method of a silver-cerium bimetallic molecular sieve catalyst for pre-synthesizing silver nanoparticles, and compared with a silver-cerium bimetallic catalyst prepared by a traditional method, namely common impregnation, the catalyst has stronger silver-cerium bimetallic interaction and shows more excellent performance of catalyzing and oxidizing toluene by ozone. Compared with bimetallic catalysts prepared by noble metals such as platinum, palladium and the like, the performance of the catalyst is also not inferior. The method adopts silver-cerium bimetal as an active component, and not only reduces the preparation cost of the catalyst, but also improves the catalytic performance through the improvement of the preparation method, thereby having great application value in practical application.
Disclosure of Invention
The invention aims to overcome the defects of high preparation cost, poor performance (low conversion rate, low mineralization rate) and the like of the existing catalyst, provides a brand-new preparation method of a silver-cerium bimetallic molecular sieve catalyst capable of pre-synthesizing silver nanoparticles on a large scale, and the prepared catalyst has excellent catalytic oxidation performance on VOCs when cooperated with ozone.
The purpose of the invention is realized by the following technical scheme:
a method for preparing a silver-cerium bimetallic molecular sieve catalyst for pre-synthesizing silver nanoparticles comprises the following steps:
(1) Dissolving silver nitrate in deionized water to obtain a solution A, dissolving polyvinylpyrrolidone and sodium borohydride in the deionized water simultaneously to obtain a solution B, and then dropwise adding a silver nitrate aqueous solution, namely the solution A, into the solution B under stirring. And after the silver nitrate solution is completely added, reacting for 5-10 min. And then centrifuging, washing and dispersing the obtained silver nanoparticles in deionized water.
(2) And (3) placing the molecular sieve in a tubular furnace, and carrying out heating calcination treatment for 5-10 h in air atmosphere to remove organic matters in the molecular sieve. Weighing cerium salt, dissolving in deionized water, adding the calcined molecular sieve after the cerium salt is fully dissolved, placing the mixture in an ultrasonic pool, performing ultrasonic dispersion, drying the mixture, and calcining to obtain CeO 2 Molecular sieve.
(3) Taking CeO in the step (2) 2 Adding the molecular sieve into the silver nanoparticle solution prepared in the step (1)Ultrasonically dispersing in an ultrasonic pool, drying and calcining to obtain Ag-CeO 2 Molecular sieve.
In the method, in the step (1), the molar volume ratio (mol/L) of the silver nitrate to the water is 0.01-0.03: 1; the polyvinylpyrrolidone has a molecular weight of 30000, 58000 or 300000; the molar volume (mol/L) ratio of the polyvinylpyrrolidone to the water is 0.2-0.4; the molar volume ratio (mol/L) of the sodium borohydride to the water is 0.005-0.02. When the ratio is too low, the Ag nanoparticles are not completely reduced, so that the yield of the Ag nanoparticles is low, when the ratio is too high, the Ag nanoparticles are excessively reduced to generate aggregation, and when the ratio is an intermediate value, the Ag nanoparticles have proper particle size and yield.
In the method, in the step (1), the stirring reaction rate is 400-600 rpm; the dropping rate of the solution A is 20-40 ml/min; the reaction time is 5-15 min after the solution A is dripped; the centrifugal rotating speed is 8000-10000 rpm; the content of the obtained silver nanoparticles in water was 21.7g/L.
In the method, in the step (2), the heating rate is 1-4 ℃/min, the calcining temperature is 400-600 ℃, and the calcining time is 4-6 h.
In the above method, in the step (2), the molar volume ratio (mol/L) of the cerium salt to water is 0.01 to 0.62; the mass-to-volume (g/ml) ratio of the molecular sieve to water is 0.2-0.9.
In the method, in the step (2), the ultrasonic power is 40-60%; the ultrasonic time is 0.5-2 h; the drying temperature is 60-100 ℃; the drying time is 0.5-6 h; the calcination temperature is 400-600 ℃; the heating rate is 0.5-2 ℃/min; the calcination time is 4-6 h.
In the above method, in the step (3), the CeO is 2 The mass-volume ratio of the molecular sieve to the silver nanoparticle solution is 0.2, 0.5 and 0.9, when the ratio is too low, the Ag nanoparticles can be aggregated, when the ratio is too high, the performance is not obviously improved, and when the ratio is in a middle value, the catalyst activity is highest; the ultrasonic power is 40% -60%; the ultrasonic time is 0.5-2 h; the drying temperature is 60-100 ℃; the said trunkThe drying time is 0.5 to 6 hours; the calcination temperature is 300-400 ℃; the heating rate is 0.5-2 ℃/min; the calcination time is 4-6 h.
In the above process, the molecular sieve configuration comprises BEA, MFI, MOR, Y, X or CHA.
The silver-cerium bimetallic molecular sieve catalyst for pre-synthesizing silver nanoparticles has the performance of efficiently degrading VOCs (volatile organic compounds) when being cooperated with ozone, toluene is completely degraded at the reaction temperature of 50 ℃, and CO is completely degraded at the reaction temperature of 80 DEG C 2 The selectivity reaches 100 percent. The catalyst has good stability, and can still maintain high toluene degradation rate after continuous reaction for 48 hours.
A silver-cerium bimetallic molecular sieve catalyst for pre-synthesizing silver nanoparticles is used in the field of air pollution control.
Compared with the prior art, the invention has the following advantages:
1. the silver-cerium bimetallic molecular sieve catalyst prepared by the method has strong interaction between silver and cerium, and the active components of the silver and the cerium are highly dispersed on the surface of the carrier.
2. The prepared silver-cerium bimetallic molecular sieve catalyst shows high CO for oxidizing VOCs under the synergistic action with ozone 2 Selectivity, i.e. complete oxidation performance.
3. Has good stability, and can still keep good toluene degradation performance after long-time reaction.
4. The preparation process is simple and easy to implement, the preparation conditions are mild, and the preparation can be carried out on a large scale.
Drawings
FIG. 1 is a TEM image of the catalyst of example 1 of this invention (represented by a catalyst with Ag loading of 0.3%).
Figure 2 is a graph of the stability of the catalyst of example 1 of the present invention (represented by a catalyst with 0.3% Ag loading).
FIG. 3 is a graph comparing the performance of the catalyst of example 1 and the performance of the silver cerium catalyst of the general impregnation method for ozone-catalyzed oxidative degradation of toluene (represented by Ag loading of 0.3%, NP for the catalyst prepared by the Ag particle method, IM for the catalyst prepared by the impregnation method, and number for Ag loading). (50mg of catalyst, gas flow 100ml min -1 Toluene concentration 30ppm, ozone concentration 300 ppm)
FIG. 4 is a graph showing the evaluation of the catalytic activity of the catalyst of example 1 of the present invention on the degradation of toluene by ozone oxidation (NP represents the catalyst prepared by Ag particle method, and the number represents the supported amount).
Detailed Description
The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto, and may be carried out with reference to conventional techniques for process parameters not particularly noted.
Example 1
(1) Dissolving 0.034g of silver nitrate in 10ml of deionized water to obtain a solution A, dissolving 0.4163g of polyvinylpyrrolidone and 0.0017g of sodium borohydride in 20ml of deionized water simultaneously to obtain a solution B, and adding a silver nitrate aqueous solution, namely the solution A into the solution B dropwise under stirring at a stirring speed of 500 rpm. And after the silver nitrate solution is completely added, reacting for 8min. After centrifugation at 10000rpm, 3 washes, the resulting silver nanoparticles were dispersed in 5ml of deionized water.
(2) And (3) placing 20g of MFI molecular sieve in a tubular furnace, and carrying out heating calcination treatment under the air atmosphere, wherein the calcination temperature is 550 ℃, the calcination time is 5h, and the heating rate is 1 ℃/min, so that organic matters in the molecular sieve are removed. Weighing 0.3099g of cerium nitrate, dissolving in 2.3ml of deionized water, adding 1g of the calcined molecular sieve after fully dissolving, placing the mixture in an ultrasonic pool, performing ultrasonic dispersion with the power of 50 percent and the ultrasonic time of 1h, drying the mixture at 80 ℃ for 2h, calcining at 550 ℃ for 5h at the temperature rise rate of 1 ℃/min to obtain CeO 2 Molecular sieve.
(3) Weighing 1g of CeO in the step (2) 2 Adding a molecular sieve into 0.15ml of the silver nanoparticle solution prepared in the step (1), adding 2.15ml of deionized water, performing ultrasonic dispersion in an ultrasonic pool with the power of 50% for 1h, drying at 80 ℃, and calcining at 350 ℃ for 5h to obtain Ag-CeO with the Ag loading of 0.3% 2 Molecular sieve.
FIG. 1 shows Ag loading0.3% of Ag-CeO 2 High resolution transmission electron micrograph of/BEA catalyst, ceO can be seen 2 And Ag particles in intimate contact, indicating successful loading of both active components. FIG. 2 shows 0.3% of Ag-CeO 2 The long-term stable performance diagram of the/BEA catalyst, after 48 hours of continuous reaction, still maintains high activity, shows the excellent performance of the catalyst. FIG. 3 is 0.3% of Ag-CeO prepared by the presynthesized silver particle method 2 0.3% of/BEA-NP, 0.3% of Ag-CeO produced by ordinary dipping method 2 Pt-CeO prepared by/BEA-IM and platinum particle method 2 Performance plots of/BEA-NP and ozone catalyzed oxidation of toluene without catalyst. As can be seen from the figure, when no catalyst is available, pure ozone has almost no activity to toluene, the performance is greatly improved after the catalyst is introduced, the catalyst prepared by the method for pre-synthesizing silver particles has better performance than the catalyst prepared by the common impregnation method, and in the aspects of toluene conversion rate, carbon dioxide selectivity, carbon balance and ozone decomposition rate, the catalyst has no output to Pt-CeO 2 The performance of the/BEA-NP catalyst demonstrates the advantages of the presynthesized silver particle process.
Example 2
(1) Dissolving 0.034g of silver nitrate in 10ml of deionized water to obtain a solution A, simultaneously dissolving 0.4163g of polyvinylpyrrolidone and 0.0038g of sodium borohydride in 20ml of deionized water to obtain a solution B, stirring at the speed of 500rpm, and adding the silver nitrate aqueous solution, namely the solution A into the solution B dropwise. And after the silver nitrate solution is completely added, reacting for 8min. After centrifugation at 10000rpm, 3 washes, the resulting silver nanoparticles were dispersed in 5ml of deionized water.
(2) 20g of MFI molecular sieve is placed in a tubular furnace, and temperature rise and calcination treatment is carried out in the air atmosphere, wherein the calcination temperature is 550 ℃, the calcination time is 5h, and the temperature rise rate is 1 ℃/min, so that organic matters in the molecular sieve are removed. Weighing 0.3099g of cerium nitrate, dissolving in 2.3ml of deionized water, adding 1g of the calcined molecular sieve after full dissolution, placing the mixture in an ultrasonic pool, performing ultrasonic dispersion with the power of 50% for 1h, and drying the mixture at 80 DEG CDrying for 2h, calcining at 550 ℃ for 5h at the heating rate of 1 ℃/min to obtain CeO 2 Molecular sieve.
(3) Weighing 1g of CeO in the step (2) 2 Adding a molecular sieve into 0.15ml of the silver nanoparticle solution prepared in the step (1), adding 2.15ml of deionized water into an ultrasonic pool for ultrasonic dispersion with the power of 50% for 1h, drying at 80 ℃, and calcining at 350 ℃ for 5h to obtain Ag-CeO with the Ag loading of 0.3% 2 Molecular sieve.
Example 3
(1) Dissolving 0.034g of silver nitrate in 10ml of deionized water to obtain a solution A, dissolving 0.4163g of polyvinylpyrrolidone and 0.0076g of sodium borohydride in 20ml of deionized water simultaneously to obtain a solution B, and adding a silver nitrate aqueous solution, namely the solution A into the solution B dropwise under stirring at a stirring speed of 500 rpm. And after the silver nitrate solution is completely added, reacting for 8min. After centrifugation at 10000rpm, 3 washes, the resulting silver nanoparticles were dispersed in 5ml of deionized water.
(2) 20g of MFI molecular sieve is placed in a tubular furnace, and temperature rise and calcination treatment is carried out in the air atmosphere, wherein the calcination temperature is 550 ℃, the calcination time is 5h, and the temperature rise rate is 1 ℃/min, so that organic matters in the molecular sieve are removed. Weighing 0.3099g of cerium nitrate, dissolving the cerium nitrate in 2.3ml of deionized water, adding 1g of the calcined molecular sieve after the cerium nitrate is fully dissolved, then placing the mixture in an ultrasonic pool, performing ultrasonic dispersion with the power of 50 percent and the ultrasonic time of 1h, drying the mixture at 80 ℃ for 2h, calcining the mixture at 550 ℃ for 5h at the temperature rise rate of 1 ℃/min, and obtaining CeO 2 Molecular sieve.
(3) Weighing 1g of CeO in the step (2) 2 Adding a molecular sieve into 0.15ml of the silver nanoparticle solution prepared in the step (1), adding 2.15ml of deionized water, ultrasonically dispersing in an ultrasonic pool with the power of 50 percent for 1h, drying at 80 ℃, and calcining at 350 ℃ for 5h to obtain the Ag-CeO with the Ag loading of 0.3 percent 2 Molecular sieve.
Example 4
(1) Dissolving 0.034g of silver nitrate in 10ml of deionized water to obtain a solution A, dissolving 0.4163g of polyvinylpyrrolidone and 0.0038g of sodium borohydride in 20ml of deionized water simultaneously to obtain a solution B, stirring at the stirring speed of 500rpm, and adding the silver nitrate aqueous solution, namely the solution A into the solution B dropwise. And after the silver nitrate solution is completely added, reacting for 8min. Then, centrifugation was performed at 10000rpm, washing was performed 3 times, and the obtained silver nanoparticles were dispersed in 5ml of deionized water.
(2) And (2) placing 20g of MFI molecular sieve in a tubular furnace, and carrying out temperature rise calcination treatment under the air atmosphere, wherein the calcination temperature is 550 ℃, the calcination time is 5h, and the temperature rise rate is 1 ℃/min, so that organic matters in the molecular sieve are removed. Weighing 0.3099g of cerium nitrate, dissolving in 2.3ml of deionized water, adding 1g of the calcined molecular sieve after fully dissolving, placing the mixture in an ultrasonic pool, performing ultrasonic dispersion with the power of 50 percent and the ultrasonic time of 1h, drying the mixture at 80 ℃ for 2h, calcining at 550 ℃ for 5h at the temperature rise rate of 1 ℃/min to obtain CeO 2 Molecular sieve.
(3) Weighing 1g of CeO in the step (2) 2 Adding a molecular sieve into 0.05ml of the silver nanoparticle solution prepared in the step (1), adding 2.25ml of deionized water, ultrasonically dispersing in an ultrasonic pool with the power of 50 percent for 1h, drying at 80 ℃, and calcining at 350 ℃ for 5h to obtain the Ag-CeO with the Ag loading of 0.1 percent 2 Molecular sieve.
Example 5
(1) Dissolving 0.034g of silver nitrate in 10ml of deionized water to obtain a solution A, simultaneously dissolving 0.4163g of polyvinylpyrrolidone and 0.0038g of sodium borohydride in 20ml of deionized water to obtain a solution B, stirring at the speed of 500rpm, and adding the silver nitrate aqueous solution, namely the solution A into the solution B dropwise. And after the silver nitrate solution is completely added, reacting for 8min. Then, centrifugation was performed at 10000rpm, washing was performed 3 times, and the obtained silver nanoparticles were dispersed in 5ml of deionized water.
(2) 20g of MFI molecular sieve is taken and placed in a tubular furnace, and heating and calcining treatment is carried out in the air atmosphere, wherein the calcining temperature is 550 ℃, the calcining time is 5h, and the heating rate is 1 ℃/min, so that the molecular sieve is removedOf (b) is an organic substance. Weighing 0.3099g of cerium nitrate, dissolving in 2.3ml of deionized water, adding 1g of the calcined molecular sieve after fully dissolving, placing the mixture in an ultrasonic pool, performing ultrasonic dispersion with the power of 50 percent and the ultrasonic time of 1h, drying the mixture at 80 ℃ for 2h, calcining at 550 ℃ for 5h at the temperature rise rate of 1 ℃/min to obtain CeO 2 Molecular sieve.
(3) Weighing 1g of CeO in the step (2) 2 Adding a molecular sieve into 2.3ml of the silver nanoparticle solution prepared in the step (1), ultrasonically dispersing in an ultrasonic pool with the power of 50 percent for 1h, drying at 80 ℃, and calcining at 350 ℃ for 5h to obtain Ag-CeO with the Ag loading of 5 percent 2 Molecular sieve.

Claims (10)

1. A preparation method of a silver-cerium bimetallic molecular sieve catalyst for catalyzing and oxidizing VOCs (volatile organic compounds) in cooperation with ozone is characterized in that silver nanoparticles with uniform size are prepared in advance and then are dispersed in CeO prepared by an impregnation method 2 The silver-cerium bimetallic molecular sieve catalyst is obtained on a molecular sieve, and the preparation method comprises the following steps:
(1) Dissolving silver nitrate in deionized water to obtain a solution A, dissolving polyvinylpyrrolidone and sodium borohydride in the deionized water simultaneously to obtain a solution B, then adding a silver nitrate aqueous solution, namely the solution A, into the solution B dropwise under stirring, reacting after the solution A is completely added, centrifuging, washing, and dispersing the obtained silver nanoparticles in the deionized water;
(2) Placing the molecular sieve in a tubular furnace, heating and calcining for 5-10 hours in an air atmosphere, and removing a template agent in the molecular sieve; weighing cerium nitrate, dissolving the cerium nitrate in deionized water, adding the calcined molecular sieve after the cerium nitrate is fully dissolved, placing the mixture in an ultrasonic pool, performing ultrasonic dispersion, drying the mixture, and calcining to obtain CeO 2 A molecular sieve;
(3) Taking CeO in the step (2) 2 Adding the molecular sieve into the silver nanoparticle solution prepared in the step (1), then performing ultrasonic dispersion in an ultrasonic pool, drying and calcining to obtain Ag-CeO 2 Molecular sieve catalyst.
2. The method for preparing the silver-cerium bimetallic sieve catalyst for the concerted ozone catalytic oxidation of VOCs according to claim 1, wherein in the step (1), the molar volume ratio mol/L of silver nitrate to water is 0.01 to 0.03:1; the polyvinylpyrrolidone has a molecular weight of 30000, 58000 or 300000; the molar volume mol/L ratio of the polyvinylpyrrolidone to water is 0.2 to 0.4; the mol/L ratio of the molar volume of the sodium borohydride to the molar volume of the water is 0.005 to 0.02.
3. The preparation method of the silver-cerium bimetallic molecular sieve catalyst for the concerted ozone catalytic oxidation of VOCs according to claim 1, wherein in the step (1), the stirring reaction rate is 400 to 600rpm; the dropping speed of the solution A is 20 to 40mL/min; after the solution A is dripped, the reaction time is 5 to 15min; the centrifugal rotating speed is 8000 to 10000rpm; the content of the silver nanoparticles in water was 21.7g/L.
4. The method for preparing the silver-cerium bimetallic molecular sieve catalyst for the concerted ozone catalytic oxidation of VOCs according to claim 1, wherein in the step (2), the mol/L ratio of the cerium nitrate to the water is 0.01 to 0.62; the mass volume ratio g/mL of the molecular sieve to water is 0.2 to 0.9.
5. The method for preparing the silver-cerium bimetallic molecular sieve catalyst for the catalytic oxidation of VOCs by ozone in cooperation with the claim 1, wherein in the step (2), the temperature rise rate of the molecular sieve calcination is 1 to 4 ℃/min, the molecular sieve calcination temperature is 400 to 600 ℃, and the molecular sieve calcination time is 4 to 6 hours; the ultrasonic power is 40% -60%; the ultrasonic time is 0.5 to 2 hours; the drying temperature is 60 to 100 ℃; the drying time is 0.5 to 6 hours.
6. The method for preparing the Ag-Ce bimetallic molecular sieve catalyst for the concerted ozone catalytic oxidation of VOCs of claim 1, wherein the CeO in the step (3) 2 The mass volume ratio of the molecular sieve to the silver nanoparticle solution is 0.2 to 0.9.
7. The method for preparing the silver-cerium bimetallic molecular sieve catalyst for the catalytic oxidation of VOCs by ozone in cooperation with the claim 1 is characterized in that in the step (3), the ultrasonic power is 40% -60%; the ultrasonic time is 0.5 to 2 hours; the drying temperature is 60 to 100 ℃; the drying time is 0.5 to 6 hours.
8. The method for preparing the silver-cerium bimetallic molecular sieve catalyst for the concerted ozone catalytic oxidation of VOCs according to claim 1, wherein in the step (3), the calcination temperature is 300-400 ℃; the heating rate is 0.5 to 2 ℃/min; the calcination time is 4 to 6 hours.
9. The method of claim 1, wherein the molecular sieve configuration comprises BEA, MFI, MOR, Y, X, or CHA.
10. The application of the silver-cerium bimetallic molecular sieve catalyst for the synergistic ozone catalytic oxidation of VOCs, which is prepared by the method according to claim 1, in the synergistic ozone catalytic oxidation of toluene.
CN202111340275.6A 2021-11-12 2021-11-12 Preparation method and application of silver-cerium bimetallic molecular sieve catalyst for catalyzing and oxidizing VOCs (volatile organic compounds) in cooperation with ozone Active CN114160184B (en)

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