Aircraft ozone converter based on zeolite coated honeycomb

Abstract

The present disclosure relates to an aircraft ozone converter based on a zeolite coated honeycomb. The invention specifically discloses an ozone converter based on modified zeolite, the ozone converter comprises a honeycomb glass fiber carrier and the modified zeolite coated on the honeycomb glass fiber carrier, based on the weight of the modified zeolite, the modified zeolite contains 5-20wt% of one or more metal elements of Mn, Co, Fe, Cu, Pt and Ag, and the balance is water. And the modified zeolite has a silica-alumina ratio of 1-15. The invention also discloses a method for preparing the ozone converter based on the modified zeolite.

Description

Zeolite-coated honeycomb-based aircraft ozone converter Technical Field

[0001] This disclosure relates to the field of ozone converters for aircraft, and more specifically, to an aircraft ozone converter based on a zeolite-coated honeycomb, and to a method for preparing such an ozone converter. More specifically, this disclosure relates to an aircraft ozone converter based on a honeycomb coated honeycomb using zeolite as a catalyst. Background Technology

[0002] Ozone (O3) is an allotrope of oxygen. Atmospheric ozone is formed through the photoelectric conversion of oxygen under ultraviolet light, and it is chemically more reactive than oxygen (O2). Civil aircraft may be exposed to high concentrations of ozone in the ozone layer (approximately 13 to 35 kilometers) during flight. If ozone-containing air enters the cabin through the aircraft's environmental control system without effective treatment, even at low concentrations, it can negatively impact human health and generate other secondary pollutants that further affect the health of passengers and crew. Furthermore, many civil aircraft utilize inert gas generation systems in their design to enhance fuel tank operational safety, and the presence of ozone in the incoming airflow can damage these systems. Therefore, the use of ozone converters to effectively remove ozone has wide applications in civil aviation.

[0003] Currently, transition metal oxides (e.g., manganese oxides) are commonly used as ozone catalysts. However, transition metal oxide-based ozone conversion technologies often perform poorly at room temperature and below, limiting their effective application in cryogenic environments for aircraft. Summary of the Invention

[0004] The purpose of this disclosure is to provide an ozone converter based on modified zeolite as a catalyst, in order to solve the problems of existing ozone converters based on transition metal oxide technology, such as difficulty in low-temperature application, low efficiency, and poor regeneration performance.

[0005] To achieve the above objectives, according to one aspect of this disclosure, a modified zeolite-based ozone converter is provided, comprising: a honeycomb glass fiber carrier, and a modified zeolite coated on the honeycomb glass fiber carrier, wherein the modified zeolite contains 5-20 wt% of one or more metallic elements selected from Mn, Co, Fe, Cu, Pt, and Ag, and the modified zeolite has a silicon-to-aluminum ratio of 1-15.

[0006] Furthermore, the modified zeolite has a silica-alumina ratio of 5-12.

[0007] Furthermore, the modified zeolite has a viscosity of 500-700 μm. 2Specific surface area within the range of / g.

[0008] Furthermore, the modified zeolite has a thickness of 600-700m. 2 Specific surface area within the range of / g.

[0009] Furthermore, the modified zeolite has one or more framework structures selected from CHA, FAU, MFI, MOR and BEA.

[0010] Furthermore, the modified zeolite has an FAU or BEA framework structure.

[0011] According to another aspect of this disclosure, a method for preparing an ozone converter based on modified zeolite is provided, comprising the following steps: a) mixing zeolite powder with water to obtain a zeolite suspension; b) mixing the zeolite suspension with a metal salt solution to allow ion exchange between the zeolite and the metal cations in the metal salt solution, thereby obtaining a modified zeolite mixture; c) drying and calcining the modified zeolite mixture to obtain modified zeolite powder; d) mixing the modified zeolite powder, a binder, an additive, and water to obtain an impregnation slurry; and e) impregnating a honeycomb glass fiber carrier into the impregnation slurry, drying, and calcining to obtain an ozone converter based on modified zeolite.

[0012] Furthermore, the modified zeolite in step e) has one or more framework structures selected from CHA, FAU, MFI, MOR and BEA.

[0013] Furthermore, the metal salt solution in step b) contains cations of one or more metal elements selected from Mn, Co, Fe, Cu, Pt, and Ag.

[0014] Furthermore, the metal salt solution in step b) comprises one or more of nitrates, sulfates, and phosphates.

[0015] Further, the binder in step d) includes one or more selected from calcium silicate, sodium silicate, aluminum sol, silica sol and montmorillonite, and the additives include one or more selected from polyacrylic acid, polyethylene ether, polyvinyl acetate, sodium polyacrylate and polyethylene glycol.

[0016] Furthermore, the modified zeolite powder obtained in step c) has a metal element content of 5-20 wt% based on the weight of the modified zeolite powder.

[0017] Further, the drying in step c) is carried out in a microwave heater at a temperature of 150-200°C for 2-4 hours, and the calcination is carried out in a muffle furnace at a temperature of 300-450°C for 3-6 hours.

[0018] Further, the drying in step e) is carried out at room temperature for 12-24 hours, and the calcination is carried out in a muffle furnace at 1-5 °C·min.-1 The temperature is increased to 70-100℃ and held for 0.5-2 hours, then increased at a rate of 1-5℃·min. -1 The heating rate is increased again to 300-450℃ for calcination for 3-6 hours.

[0019] As mentioned above, existing ozone converters suffer from technical problems such as difficulty in low-temperature applications, low conversion efficiency, and poor regeneration performance. According to the technical solution of this disclosure, an ozone converter based on modified zeolite is provided. The modified zeolite of this invention achieves specific types and amounts of cation compensation for the negative charge of the aluminum-containing tetrahedra in the zeolite framework structure. The ozone converter based on modified zeolite prepared by this invention has a silicon-aluminum ratio within a specific range, as well as the types and specific contents of cations. Based on the microporous-mesoporous channels and cation active sites of the modified zeolite, the ozone converter of this invention can simultaneously perform physical adsorption and catalytic decomposition of ozone components, thereby achieving improved ozone adsorption catalytic performance. The ozone converter based on modified zeolite of this invention exhibits superior ozone adsorption catalytic performance compared to existing commercial ozone converters under low-temperature conditions, and can achieve a degradation rate of 1% within 30 hours under low-temperature conditions.

[0020] Furthermore, using the method disclosed herein, an ozone converter was prepared with modified zeolite as the catalytically active component and honeycomb glass fiber as the support for the catalytically active component. A metal salt solution was mixed with zeolite to form a non-Newtonian fluid mixture, which was then dried using microwaves and calcined to obtain the modified zeolite catalyst. The specific process of this invention allows for the control of the distribution of modified cations in the zeolite framework, thereby achieving stable catalytic performance of the modified zeolite. The modified zeolite catalyst was mixed with water, binder, dispersant, and additives to form a slurry, and the glass fiber honeycomb support was impregnated in the slurry, dried, and calcined to obtain the catalytic core for the ozone converter. The honeycomb support made of glass fiber further utilizes high mass transfer efficiency, low density, and good low-pressure and high-temperature resistance. In addition, during the coating preparation process, the glass fiber support has a large specific surface area and can adhere more catalytically active components. Therefore, the modified zeolite-based ozone converter prepared by this invention also possesses high specific surface area, high catalytic activity, and good material stability. Furthermore, the novel laboratory-grade modified zeolite-based catalyst of this invention exhibits superior performance compared to existing conventional ozone catalysts under both low and high temperature conditions. Excellent results are provided by near-zero degradation rates at 170°C and 1% degradation rates at -5°C. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present disclosure will now be described in detail with reference to the embodiments.

[0022] To address the shortcomings of existing ozone catalysts mentioned in the background art, one specific embodiment of this disclosure provides an ozone converter based on modified zeolite. The ozone converter includes: a honeycomb glass fiber carrier and modified zeolite coated on the honeycomb glass fiber carrier, wherein the modified zeolite contains 5-20 wt% of one or more metallic elements selected from Mn, Co, Fe, Cu, Pt, and Ag based on the weight of the modified zeolite powder, and the modified zeolite has a silicon-to-aluminum ratio of 1-15.

[0023] Preferably, the modified zeolite contains 6-16 wt% of one or more of the aforementioned metallic elements. For example, the modified zeolite contains 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 wt% of one or more of the aforementioned metallic elements.

[0024] The ozone converter of this invention achieves a specific range of silicon-to-aluminum ratio and specific types and amounts of cations by compensating for the negative charge of the aluminum-containing tetrahedra in the zeolite framework structure with specific types and amounts of cations. The specific silicon-to-aluminum ratio of the modified zeolite can improve the catalytic activity of the ozone converter of this invention under low-temperature conditions and effectively provide thermal stability to the catalyst, helping to maintain structural integrity during high-temperature regeneration.

[0025] As used in this article, the term "low temperature" refers to room temperature or below room temperature, such as -5°C.

[0026] Before modification, the framework structure of zeolite consists of SiO4 and AlO4 tetrahedral units (BBU). The negative charge of the AlO4 tetrahedral units in the framework structure is generated by cations (such as H+) located inside the cavities. + Na + (etc.) balance, after modification with specific metal cations of a specific content within the scope of this disclosure, these metal cations can be highly distributed in the modified zeolite without destroying the original structure of the zeolite; the cation-oxygen unit cluster has high adsorption energy and low energy barrier to the rate-limiting step of the reaction, thereby improving the catalytic efficiency and ozone conversion rate of the modified zeolite.

[0027] Based on the microporous-mesoporous channels and cationic active sites of modified zeolite, the ozone converter of this invention can simultaneously perform physical adsorption and catalytic decomposition of ozone components, thereby achieving significantly improved ozone adsorption catalytic performance. The modified zeolite-based ozone converter of this invention exhibits excellent ozone adsorption catalytic performance and post-regeneration catalytic performance under low-temperature conditions.

[0028] In some examples, the modified zeolite has a silicon-to-aluminum ratio (Si / Al or SiO2 / Al2O3) of 5-12. For example, the modified zeolite has a silicon-to-aluminum ratio of 5, 6, 7, 8, 9, 10, 11, or 12. Preferably, the modified zeolite has a silicon-to-aluminum ratio of 12. The silicon-to-aluminum ratio of the modified zeolite, within the scope of this disclosure, can further improve catalytic activity and provide thermal stability to the catalyst, thereby further improving the efficiency of the catalytic reaction and further improving the structural integrity of the catalyst during regeneration at high temperatures.

[0029] In some instances, modified zeolites exhibit 500-700 m 2 Specific surface area in the range of / g. For example, modified zeolites have specific surface areas of 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, and 700 m. 2 The specific surface area is 603-678 m² / g. Preferably, the modified zeolite has a specific surface area of ​​603-678 m² / g. 2 The specific surface area is 611-665 m² / g. More preferably, the modified zeolite has a specific surface area of ​​611-665 m² / g. 2 The specific surface area is 621-645 m² / g. More preferably, the modified zeolite has a specific surface area of ​​621-645 m² / g. 2 The specific surface area of ​​the modified zeolite is within the scope of this invention, which can effectively provide porosity and catalytic active sites, thereby further improving the efficiency of catalytic reactions under low-temperature conditions, and can also help remove impurities adsorbed on the catalyst surface, thereby further improving the catalyst regeneration capacity.

[0030] In some instances, the modified zeolite has one or more framework structures selected from CHA, FAU, MFI, MOR, and BEA. For example, the zeolite has a CHA framework structure, a FAU framework structure, an MFI framework structure, a MOR framework structure, or a BEA framework structure.

[0031] Preferably, the modified zeolite has an FAU or BEA framework structure.

[0032] When the framework structure of the modified zeolite is within the scope of this disclosure, it can achieve small or medium pore sizes, improve the molecular sieving effect, enhance ozone adsorption and accommodate more metal cations, and further improve catalytic efficiency.

[0033] Another specific embodiment of this disclosure provides a method for preparing an ozone converter based on modified zeolite, the method comprising the following steps: a) mixing zeolite powder with water to obtain a zeolite suspension; b) mixing the zeolite suspension with a metal salt solution and stirring to allow the zeolite to exchange ions with the metal cations in the metal salt solution to obtain a modified zeolite mixture; c) drying and calcining the modified zeolite mixture to obtain modified zeolite powder; d) mixing the modified zeolite powder, a binder, an additive, and water to obtain an impregnation slurry; and e) impregnating a honeycomb glass fiber carrier into the impregnation slurry, drying, and calcining to obtain the ozone converter based on modified zeolite.

[0034] The specific process of this invention allows for the control of the distribution of modified metal cations in the zeolite framework, thereby enabling the modified zeolite to achieve improved and stable catalytic performance. A slurry is prepared by mixing the modified zeolite catalyst with water, a binder, a dispersant, and additives. A glass fiber honeycomb carrier is then impregnated in the slurry, dried, and calcined to obtain the catalytic core for an ozone converter. This preparation process utilizes a honeycomb carrier made of glass fiber, which features high mass transfer efficiency, low density, and good low-pressure and high-temperature resistance. Furthermore, during coating preparation, the glass fiber carrier has a large specific surface area and can adhere to more catalytically active components. Therefore, the ozone converter based on modified zeolite prepared by this invention exhibits high specific surface area, high catalytic activity, and good material stability.

[0035] In some instances, the modified zeolite in step e) has one or more framework structures selected from CHA, FAU, MFI, MOR, and BEA. When the framework structure of the modified zeolite is within the scope of this disclosure, it can achieve small or medium pore sizes, improve molecular sieving effects, enhance ozone adsorption, and accommodate more metal cations, further improving catalytic efficiency.

[0036] In some instances, the metal salt solution in step b) contains cations of one or more metal elements selected from Mn, Co, Fe, Cu, Pt, and Ag. For example, the metal salt solution contains cations of Mn, Co, Fe, Cu, Pt, and / or Ag. After modification with specific amounts of specific metal cations within the scope of this disclosure, these metal cations can be highly distributed in the modified zeolite without disrupting its original structure; the cation-oxygen unit clusters possess high adsorption energy and low energy barrier to the rate-limiting step of the reaction, thereby improving the catalytic efficiency and ozone conversion rate of the modified zeolite.

[0037] In some instances, the metal salt solution in step b) comprises one or more of nitrates, sulfates, and phosphates. Preferably, the metal salt solution comprises nitrates. The type of metal salt solution chosen within the scope of this disclosure can improve the solubility of the metal salt solution, accelerate and improve the distribution of metal cations, thereby increasing the modification efficiency.

[0038] In some instances, the binder in step d) comprises one or more selected from calcium silicate, sodium silicate, alumina sol, silica sol, and montmorillonite, and the additive comprises one or more selected from polyacrylic acid, polyethylene ether, polyvinyl acetate, sodium polyacrylate, and polyethylene glycol. Preferably, the binder comprises calcium silicate, sodium silicate, or alumina sol, and the additive comprises polyacrylic acid, polyethylene ether, or polyvinyl acetate. The type of binder, within the scope of this disclosure, can help to uniformly disperse the catalytically active components on the support, preventing aggregation of the catalytically active components, thereby further improving the activity of the catalyst.

[0039] In some instances, the modified zeolite powder obtained in step c) has a metal element content of 5-20 wt% based on the weight of the modified zeolite powder. For example, the modified zeolite powder has a metal element content of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 wt% based on the weight of the modified zeolite powder.

[0040] In some examples, the drying in step c) is carried out in a microwave heater at a temperature of 150-200°C for 2-4 hours, and the calcination is carried out in a muffle furnace at a temperature of 300-450°C for 3-6 hours. For example, the drying temperature in step c) is 150, 160, 170, 180, 190, or 200°C, and the drying time is 2, 2.5, 3, 3.5, or 4 hours. For example, the calcination temperature in step c) is 300, 310, 320, 330, 340, 360, 380, 400, 420, 430, 440, or 450°C, and the calcination time is 3, 3.5, 4, 4.5, 5, 5.5, or 6 hours. The drying and calcination conditions of the modified zeolite mixture within the scope of this disclosure can prevent excessive oxidation or decomposition of the catalytic active component, fully remove moisture from the catalytic active component, and effectively activate the catalytic active component, thereby further improving the catalytic performance of the catalytic active component at low temperatures.

[0041] In some instances, the drying in step e) is carried out at room temperature for 12-24 hours, and the calcination is performed in a muffle furnace at 1-5 °C / min. -1 The temperature is increased to 70-100℃ and held for 0.5-2 hours, then increased at a rate of 1-5℃·min. -1The temperature is then raised again to 300-450℃ and calcined for 3-6 hours. For example, in step e), the drying time is 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 hours, the calcination temperature is 70, 80, 90, 100, 110, 120℃, and the heating rate is 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5℃·min. -1 The temperature was then raised again to 300, 320, 340, 360, 380, 400, 420, 430, 440, and 450°C, with high-temperature calcination times of 3, 3.5, 4, 4.5, 5, 5.5, and 6 hours, respectively. The drying and calcination conditions of the catalyst composition within the scope of this disclosure can prevent the decomposition of the catalytically active components, fully remove moisture from the catalytically active components, effectively remove binders and additives from the composition, and effectively activate the catalytically active components, thereby further improving the catalytic performance of the catalytically active components at low temperatures.

[0042] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0043] Example 1

[0044] (1) Preparation process of modified zeolite:

[0045] 100g of zeolite powder (Y-type zeolite) was weighed and placed in a beaker. 75mL of deionized water was added dropwise to the beaker while continuously stirring to obtain a zeolite suspension. Subsequently, 70g of a metal nitrate solution (containing 25wt% Co(NO3)2 and 25wt% Mn(NO3)2) was added to the zeolite suspension at room temperature, and the mixture was stirred continuously for 0.5h to obtain a modified zeolite mixture. The modified zeolite mixture was then placed in a microwave heater and dried at 170℃ for 3h. The resulting dried solid was then placed in a muffle furnace and calcined at 350℃ for 4h. After the muffle furnace cooled naturally, the modified zeolite powder was obtained. The chemical composition of the modified zeolite powder was determined by X-ray fluorescence spectrometry (XRF), and it was calculated to have a silicon-to-aluminum ratio of 12, with Co and Mn elemental contents of 6wt% of the total weight of the modified zeolite.

[0046] The modified zeolite powder had a surface area of ​​624 m², as measured by a fully automated surface area analyzer (BET). 2 ·g -1 The specific surface area was measured by X-ray diffraction (XRD) to determine its FAU-type framework structure.

[0047] (2) Coating of modified zeolite:

[0048] Mix 25g of modified zeolite powder, 4g of sodium silicate (binder), 0.1g of polyvinyl acetate (auxiliary agent) and 71mL of deionized water together, and stir the mixture for 24 hours using a magnetic stirrer to prepare a uniform impregnation slurry.

[0049] The honeycomb glass fiber carrier, after being purged under N2, was placed in the above impregnation slurry and impregnated for 0.5 h. The honeycomb glass fiber carrier was then removed and dried at room temperature for 24 h. Finally, it was placed in a muffle furnace and heated at 2 °C / min. -1 The temperature was increased to 70°C and held for 1 hour, then increased at a rate of 2°C / min. -1 The heating rate was increased again to 400℃ and calcined for 3 hours to obtain a modified zeolite-coated honeycomb glass fiber carrier.

[0050] Example 2

[0051] (1) Preparation process of modified zeolite:

[0052] 100g of zeolite powder (Y-type zeolite) was weighed and placed in a beaker. 40mL of deionized water was added dropwise to the beaker while continuously stirring to obtain a zeolite suspension. Subsequently, 130g of a metal nitrate solution (containing 25wt% Co(NO3)2 and 25wt% Fe(NO3)2) was added to the zeolite suspension at room temperature, and the mixture was stirred continuously for 0.5h to obtain a modified zeolite mixture. The modified zeolite mixture was then placed in a microwave heater and dried at 150℃ for 2h. The resulting dried solid was then placed in a muffle furnace and calcined at 300℃ for 3h. After the muffle furnace cooled naturally, the modified zeolite powder was obtained. The chemical composition of the modified zeolite powder was determined by X-ray fluorescence spectrometry (XRF), and it was calculated to have a silicon-to-aluminum ratio of 5, with Co and Fe elements accounting for 14wt% of the total weight of the modified zeolite.

[0053] The modified zeolite powder had a surface area of ​​617 μm, as measured by a fully automated surface area analyzer (BET). 2 ·g -1 The specific surface area was measured by X-ray diffraction (XRD) to determine its FAU-type framework structure.

[0054] (2) Coating of modified zeolite:

[0055] Mix 25g of modified zeolite powder, 4g of aluminum sol (binder), 0.1g of polyacrylic acid (auxiliary agent) and 71mL of deionized water together, and stir the mixture for 24 hours using a magnetic stirrer to prepare a uniform impregnation slurry.

[0056] The honeycomb glass fiber carrier, after being purged under N2, was placed in the above impregnation slurry and impregnated for 0.5 h. The honeycomb glass fiber carrier was then removed and dried at room temperature for 24 h. Finally, it was placed in a muffle furnace and heated at 1 °C / min. -1 The temperature was increased to 70℃ and held for 0.5 h, then increased at a rate of 1℃·min. -1 The heating rate was increased again to 300℃ and calcined for 3 hours to obtain a modified zeolite-coated honeycomb glass fiber carrier.

[0057] Example 3

[0058] (1) Preparation process of modified zeolite:

[0059] 100g of zeolite powder (BETA type zeolite) was weighed and placed in a beaker. 40mL of deionized water was added dropwise to the beaker with continuous stirring to obtain a zeolite suspension. Subsequently, 120g of a metal nitrate solution (containing 25wt% Mn(NO3)2 and 25wt% Fe(NO3)2) was added to the zeolite suspension at room temperature. After reacting for 0.5h, a modified zeolite mixture was obtained. The modified zeolite mixture was then placed in a microwave heater and dried at 200℃ for 4h. The resulting dried solid was then placed in a muffle furnace and calcined at 450℃ for 6h. After the muffle furnace cooled naturally, the modified zeolite powder was obtained. The chemical composition of the modified zeolite powder was determined by X-ray fluorescence spectrometry (XRF), and it was calculated to have a silicon-to-aluminum ratio of 12, with Mn and Fe elemental contents accounting for 16wt% of the total weight of the modified zeolite.

[0060] The modified zeolite powder had a surface area of ​​692 μm, as measured by a fully automated surface area analyzer (BET). 2 ·g -1 The specific surface area was measured by X-ray diffraction (XRD) and it was found to have a BET framework structure.

[0061] (2) Coating of modified zeolite:

[0062] Mix 25g of modified zeolite powder, 4g of calcium silicate (binder), 0.1g of polyethylene ether (additive) and 71mL of deionized water together, and stir the mixture for 24 hours using a magnetic stirrer to prepare a uniform impregnation slurry.

[0063] The honeycomb glass fiber carrier, after being purged under N2, was placed in the above impregnation slurry and impregnated for 0.5 h. The honeycomb glass fiber carrier was then removed and dried at room temperature for 24 h. Finally, it was placed in a muffle furnace and heated at 5 °C / min. -1 The temperature was increased to 100℃ and held for 2 hours, then increased at a rate of 5℃·min. -1The heating rate was increased again to 450℃ and calcined for 6 hours to obtain a modified zeolite-coated honeycomb glass fiber carrier.

[0064] Comparative Example 1

[0065] The modified zeolite-coated honeycomb glass fiber carrier was prepared in the same manner as in Example 1, except that the amount of metal nitrate solution (in which the content of Ni(NO3)2 is 50 wt%) added is 2 wt% (by weight of zeolite), and the resulting modified zeolite has a silicon-to-aluminum ratio of 40 and the Ni element content is 3 wt% of the total weight of the modified zeolite.

[0066] Comparative Example 2

[0067] The modified zeolite-coated honeycomb glass fiber carrier was prepared in the same manner as in Example 1, except that the amount of metal nitrate solution (in which the content of Zn(NO3)2 was 50 wt%) was added was 15 wt%, and the resulting modified zeolite had a silicon-to-aluminum ratio of 40 and the Zn element content was 2.5 wt% of the total weight of the modified zeolite.

[0068] Comparative Example 3

[0069] Modified zeolite-coated honeycomb glass fiber carriers were prepared in the same manner as in Example 1, except that during the preparation of the modified zeolite, the modified zeolite mixture was placed in a microwave heater and dried at 120°C for 1.5 h. The resulting dried solid was then placed in a muffle furnace and calcined at 250°C for 2.5 h.

[0070] Comparative Example 4

[0071] Modified zeolite-coated honeycomb glass fiber carriers were prepared in the same manner as in Example 1, except that cordierite carriers were used instead of honeycomb glass fiber carriers.

[0072] Comparative Example 5

[0073] Modified zeolite-coated honeycomb glass fiber carriers were prepared in the same manner as in Example 1, except that in the modified zeolite coating step, after the honeycomb glass fiber carrier was impregnated, it was dried at room temperature for 10 hours and then placed in a muffle furnace at 0.5°C·min. -1 The temperature was increased to 50℃ and held for 0.5 h, then increased at a rate of 0.5℃·min. -1 The heating rate was increased again to 250℃ and calcined for 2.5 hours.

[0074] Comparative Example 6

[0075] The modified zeolite-coated honeycomb glass fiber carrier was prepared in the same manner as in Example 1, except that in the modified zeolite coating step, after the honeycomb glass fiber carrier was impregnated, it was dried at room temperature for 28 hours and then placed in a muffle furnace at 6°C·min. -1 The temperature was increased to 120℃ and held for 2.5 hours, then increased at a rate of 6℃·min. -1 The heating rate was increased again to 500℃ and calcined for 7 hours.

[0076] Performance testing

[0077] 1. Ozone removal test

[0078] By adjusting the gas supply unit and the ozone generation unit, a mixed gas containing ozone and air components is generated. The temperature of this mixed gas, used for the ozone removal reaction, is then adjusted to -5°C by a temperature control unit before being introduced into the reactor for the ozone catalytic reaction. The ozone concentration before and after the gas intake is measured, and the ozone conversion rate is calculated.

[0079] 2. Catalyst regeneration performance test

[0080] The used modified zeolite catalyst was regenerated by purging it with air at 180°C for 2 hours. The ozone conversion rate of the regenerated catalyst was tested using the same method as described in the ozone removal test.

[0081] Table 1

[0082] Group Ozone Conversion Rate (%) Ozone Conversion Rate After Catalyst Regeneration (%) Example 1 100 100 Example 2 95 95 Example 3 94 94 Comparative Example 1 84 73 Comparative Example 2 82 70 Comparative Example 3 77 50 Comparative Example 4 72 68 Comparative Example 5 63 46 Comparative Example 6 68 49 surface

[0083] The results above show that, compared to Comparative Examples 1-6, the modified zeolite-coated honeycomb glass fiber carriers of Examples 1-3 of the present invention exhibit excellent ozone adsorption catalytic performance under low-temperature conditions, which is reflected in a significantly improved ozone conversion rate of the ozone converter. Furthermore, compared to Comparative Examples 1-6, the modified zeolite-coated honeycomb glass fiber carriers of Examples 1-3 of the present invention, after catalyst regeneration following use, exhibited an ozone conversion rate comparable to that before use, which is significantly better than that of Comparative Examples 1-6.

[0084] The above embodiments are merely descriptions of the technical solutions of this disclosure and are not intended to limit its scope. Although those skilled in the art can make various modifications based on the above examples, all modifications should be within the protection scope of this disclosure as long as they do not depart from its design spirit.

[0085] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those described herein.

[0086] The above description is only related to specific embodiments of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. An ozone converter based on modified zeolite, characterized in that, The ozone converter comprises: a honeycomb glass fiber carrier, and a modified zeolite coated on the honeycomb glass fiber carrier, wherein the modified zeolite contains 5-20 wt% of one or more metallic elements selected from Mn, Co, Fe, Cu, Pt and Ag, and the modified zeolite has a silicon-to-aluminum ratio of 1-15, based on the weight of the modified zeolite.

2. The ozone converter based on modified zeolite according to claim 1, characterized in that, The modified zeolite has a silicon-to-aluminum ratio of 5-12.

3. The ozone converter based on modified zeolite according to claim 1 or 2, characterized in that, The modified zeolite has a content of 500-700 m 2 The modified zeolite preferably has a specific surface area in the range of / g, with a surface area of ​​600-700 m² / g. 2 Specific surface area within the range of / g.

4. The ozone converter based on modified zeolite according to claim 1 or 2, characterized in that, The modified zeolite has one or more framework structures selected from CHA, FAU, MFI, MOR and BEA.

5. The ozone converter based on modified zeolite according to claim 1 or 2, characterized in that, The modified zeolite has an FAU or BEA framework structure.

6. A method for preparing the modified zeolite-based ozone converter of claim 1, characterized in that, The method includes the following steps: a) mixing zeolite powder with water to obtain a zeolite suspension; b) mixing the zeolite suspension with a metal salt solution to allow ion exchange between the zeolite and the metal cations in the metal salt solution, thereby obtaining a modified zeolite mixture; c) drying and calcining the modified zeolite mixture to obtain modified zeolite powder; d) mixing the modified zeolite powder, binder, additives, and water to obtain an impregnation slurry; and e) impregnating a honeycomb glass fiber carrier into the impregnation slurry, drying, and calcining to obtain the modified zeolite-based ozone converter.

7. The method according to claim 6, characterized in that, The modified zeolite in step e) has one or more framework structures selected from CHA, FAU, MFI, MOR and BEA.

8. The method according to claim 6 or 7, characterized in that, The metal salt solution in step b) contains cations of one or more metal elements selected from Mn, Co, Fe, Cu, Pt, and Ag.

9. The method according to claim 6 or 7, characterized in that, The metal salt solution in step b) contains one or more of nitrates, sulfates, and phosphates.

10. The method according to claim 6 or 7, characterized in that, The binder in step d) includes one or more selected from calcium silicate, sodium silicate, aluminum sol, silica sol and montmorillonite, and the additives include one or more selected from polyacrylic acid, polyethylene ether, polyvinyl acetate, sodium polyacrylate and polyethylene glycol.

11. The method according to claim 6 or 7, characterized in that, The modified zeolite powder obtained in step c) has a metal element content of 5-20 wt% based on the weight of the modified zeolite powder.

12. The method according to claim 6 or 7, characterized in that, The drying in step c) is carried out in a microwave heater at a temperature of 150-200℃ for 2-4 hours, and the calcination is carried out in a muffle furnace at a temperature of 300-450℃ for 3-6 hours.

13. The method according to claim 6 or 7, characterized in that, The drying in step e) is carried out at room temperature for 12-24 hours, and the calcination is carried out in a muffle furnace at 1-5 °C·min. -1 The temperature is increased to 70-100℃ and held for 0.5-2 hours, then increased at a rate of 1-5℃·min. -1 The heating rate is increased again to 300-450℃ for calcination for 3-6 hours.