A manganese-based fibrous catalytic material, its preparation method and use

Abstract

The application belongs to the technical field of new materials, and discloses a preparation method of a manganese-based fiber catalytic material, specifically: polymer fibers are subjected to pre-oxidation treatment to obtain pre-oxidized polymer fibers; the pre-oxidized polymer fibers are subjected to in-situ oxidation by using a potassium permanganate in-situ oxidation method to obtain a manganese-based polymer fiber catalytic material precursor; the manganese-based polymer fiber catalytic material precursor is subjected to ozone in-situ activation treatment by using an ozone gas flow, and the manganese-based fiber catalytic material is obtained. The manganese-based fiber catalytic material prepared by the application has stable oxidation resistance, high thermal stability, excellent catalytic performance, and mild preparation conditions. In addition, the form is not limited, and any form such as random fibers, wool, needle punched cloth, knitted cloth and the like can be applied, so that the manganese-based fiber catalytic material is not only convenient to fill, but also greatly widens the use depth and breadth of the catalytic material.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, specifically relating to a manganese-based fiber catalytic material, its preparation method, and its application. Background Technology

[0002] Functionalizing common textile fibers (synthetic and natural fibers) to retain their original characteristics and advantages while acquiring various special properties and applications has garnered increasing attention in recent years. Textile fibers are readily available, diverse, and reasonably priced, making them an excellent source of raw materials for new materials. Chemical modification is a crucial method for fiber functionalization. It involves the active chemical groups on the fiber reacting with certain molecules or ions, or through ultrasonic, microwave, or heat-assisted reactions, to impart new surface chemical properties to the fiber, thereby acquiring new functions such as antistatic properties, water absorption and retention, adsorption and separation, antibacterial and deodorizing properties, and catalysis. Chemical modification can be achieved using different fibers as raw materials and through various processing methods and processes. Currently, most supported metal oxide catalysts use porous materials such as metal oxides or molecular sieves as substrates. Although catalysts prepared with these substrates exhibit excellent stability and dispersibility, their morphology is difficult to change, making filling and replacement challenging in industrial applications. Furthermore, most active sites on molecular sieve or metal oxide-based catalysts are located within the particles, and internal diffusion significantly impacts catalytic performance during actual reactions. Additionally, intermediate product particles generated during the reaction easily deposit and clog the catalyst channels, leading to reduced catalyst activity. Studies have shown that a rich acid-base microenvironment on the catalyst surface is crucial for enhancing catalytic performance. Despite this, due to the involvement of organic polymer fibers, the active sites of the prepared catalysts are inevitably covered to some extent by organic debris or inactive components. Unlike inorganic supports, they cannot undergo high-temperature oxidation activation, resulting in fewer active sites on the fiber surface and severe coverage by organic debris, leading to significantly lower catalytic activity compared to similar inorganic supported catalysts. Furthermore, the literature "Duan W, Tang K, Zhao L, et al. MnO xThe study, titled "Nanoparticle-loaded polyacrylonitrile fibers for efficient catalytic ozonation of toluene[J]. Atmospheric Pollution Research, 2024, 15 (5):102079," indicates that the polymer fiber support degrades during the ozone oxidation of toluene using polymer fibers loaded with manganese oxides. Therefore, for organic fiber catalysts used in ozone oxidation reactions, further improvements in their heat resistance and catalytic activity are necessary. Summary of the Invention

[0003] In view of the problems and shortcomings of the existing technology, the purpose of this invention is to provide a manganese-based fiber catalytic material, its preparation method and application.

[0004] To achieve the objectives of this invention, the technical solution adopted is as follows:

[0005] The first aspect of this invention provides a method for preparing a manganese-based fiber catalytic material. The method comprises: pre-oxidizing polymer fibers to obtain pre-oxidized polymer fibers; in-situ oxidizing the pre-oxidized polymer fibers using potassium permanganate to obtain a manganese-based polymer fiber catalytic material precursor; and in-situ activating the manganese-based polymer fiber catalytic material precursor with ozone using an ozone stream to obtain the manganese-based fiber catalytic material.

[0006] According to the above preparation method, preferably, the temperature of the ozone in-situ activation treatment is 110–130 °C, and the time is 2–8 h. More preferably, the temperature of the ozone in-situ activation treatment is 110–120 °C, and the time is 2–6 h.

[0007] According to the above preparation method, preferably, the concentration of ozone in the ozone gas stream during the ozone in-situ activation treatment is 10–40 mg / L. More preferably, the concentration of ozone in the ozone gas stream is 10–30 mg / L.

[0008] According to the above preparation method, preferably, the mass hourly space velocity (MSV) of the ozone gas stream during the in-situ ozone activation treatment is 240,000–1,200,000 mL / (g·h). More preferably, the MSV of the ozone gas stream during the in-situ ozone activation treatment is 480,000–1,200,000 mL / (g·h).

[0009] According to the above preparation method, preferably, the specific operation of in-situ oxidation of the pre-oxidized polymer fiber by potassium permanganate oxidation method is as follows: the pre-oxidized polymer fiber is added to potassium permanganate solution for oxidation reaction, the polymer fiber is collected after the reaction is completed, and the polymer fiber is washed and dried to obtain manganese-based polymer fiber catalytic material precursor.

[0010] According to the above preparation method, preferably, the concentration of the potassium permanganate solution is 20-100 mmol / L, and the liquid-solid ratio of the potassium permanganate solution to the pre-oxidized polymer fiber is (20-200) mL:1g (that is, 20-200 mL of potassium permanganate solution is added to each 1g of pre-oxidized polymer fiber for pre-oxidation reaction).

[0011] According to the above preparation method, preferably, the oxidation reaction temperature is 10-40 °C and the oxidation reaction time is 0.5-12 h.

[0012] According to the above preparation method, preferably, the pre-oxidation treatment specifically involves heat-treating the polymer fibers in an oxygen-containing gas.

[0013] According to the above preparation method, preferably, the heat treatment temperature is 200-250 °C, the heat treatment time is 0.5-4 h, and the flow rate of the oxygen-containing gas is 100-500 mL / min.

[0014] According to the above preparation method, preferably, the pre-oxidation treatment is as follows: placing the polymer fiber in an oxygen-containing gas, heating to 200-250°C, and holding for heat treatment for 0.5-4 hours. More preferably, the heating rate is 2-20°C / min.

[0015] According to the above preparation method, preferably, the polymer fiber is an acrylic fiber or a modified acrylic fiber.

[0016] According to the above preparation method, preferably, the modified acrylic fiber is an acrylic fiber grafted with amine groups, wherein the amine groups are grafted onto the acrylic fiber by reacting a polyamine compound with the -CN group in the acrylic fiber.

[0017] According to the above preparation method, preferably, the preparation method of the acrylic fiber grafted with amine groups is as follows: the acrylic fiber is added to a polyamine compound solution for swelling treatment, and after swelling, it is reacted at 100-150 °C for 1-12 h. After the reaction is completed, it is cooled, washed, and dried to obtain the acrylic fiber grafted with amine groups. More preferably, the swelling treatment temperature is 60-80 °C, and the swelling treatment time is 4-12 h.

[0018] According to the above preparation method, preferably, the polyamine compound is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, and polyethylenepolyamine.

[0019] According to the above preparation method, preferably, the amount of the polyamine compound solution is: 20ml to 200ml of polyamine compound solution is added to each 1g of acrylic fiber for swelling treatment, and the mass fraction of the polyamine compound in the polyamine compound solution is 5% to 100%.

[0020] According to the above preparation method, preferably, the solvent of the polyamine compound solution is at least one selected from water, ethylene glycol, propylene glycol, and glycerol.

[0021] According to the preparation method described above, preferably, the amino group includes a primary amino group and / or a secondary amino group. More preferably, the nitrogen heterocycle is generated by cyclization of one or more of a cyano group, a carbonyl group, and an amino group.

[0022] A second aspect of the present invention provides a manganese-based fiber catalytic material prepared using the preparation method described in the first aspect above.

[0023] According to the above-mentioned manganese-based fiber catalytic material, preferably, the manganese-based fiber catalytic material is in one or more of the following forms: fibrous, yarn-like, needle-punched cloth-like, and knitted cloth-like.

[0024] The third aspect of the present invention provides the application of the manganese-based fiber catalytic material described in the second aspect above in catalysts.

[0025] According to the above application, preferably, the catalyst includes a catalyst in the ozone oxidation process; more preferably, the ozone oxidation includes ozone oxidation degradation of benzene series compounds in the gas phase; the benzene series compounds include toluene and / or benzene; and the degradation temperature is 70-110 °C.

[0026] Compared with the prior art, the positive and beneficial effects achieved by the present invention are as follows:

[0027] (1) Due to the involvement of organic polymer fibers, the active sites of the prepared catalyst are more or less covered by organic fragments or inactive components, but they cannot be activated by high-temperature oxidation like inorganic supports. As a result, the active sites on the surface of the prepared fibers are few and severely covered by organic fragments, which leads to a significant reduction in their catalytic activity compared with similar inorganic support catalysts. In this invention, acrylic fibers are used as the matrix material. Amino functional groups are grafted onto the surface of acrylic fibers by chemical grafting to prepare amino fibers (i.e., acrylic fibers grafted with amino groups). Then, the amino fibers are placed in an air atmosphere for pre-oxidation to obtain pre-oxidized amino fibers. The pre-oxidized amino fibers are then processed by in-situ oxidation with potassium permanganate. A precursor for a manganese-based polymer fiber catalytic material was prepared, and then ozone in-situ activation treatment was performed on the precursor using an ozone flow. During the ozone in-situ activation treatment, based on the catalytic activity of some manganese oxides on the fiber surface, the organic fragments covering the surface of the catalytic active sites were stripped and degraded through autocatalytic ozone oxidation, resulting in an increase in the number of exposed manganese oxide catalytic active sites on the surface of the polymer fiber catalytic material. This improved the catalytic performance of the polymer fiber catalytic material and effectively solved the problem of low activity or deactivation of the catalytic material due to the covering of catalytic active sites on the surface of the manganese-based polymer fiber catalytic material. At the same time, the ozone in-situ activation treatment could also further improve the thermal stability of the manganese-based polymer fiber catalytic material.

[0028] (2) The manganese-based fiber catalytic material prepared by the present invention can be used to catalyze the oxidation and degradation of pollutants such as volatile organic compounds and malodorous pollutants by ozone. Moreover, when the manganese-based fiber catalytic material of the present invention is used to degrade pollutant gas with a toluene concentration of 100 ppm under the conditions of space velocity of 120000 mL / (g·h), reaction temperature of 90℃, and ozone concentration of 4.0-4.5 mg / L, the toluene removal rate reaches 99.2% to 100%, and the selectivity of inorganic carbon oxides (carbon monoxide and carbon dioxide) in the product is greater than 99%. Under the same degradation conditions, the toluene removal rate is only 65% ​​to 83% when using manganese-based polymer fiber material precursor without ozone activation as catalyst. Therefore, compared with the process of not using ozone in-situ activation treatment, the catalytic activity of the manganese-based fiber catalytic material prepared by the present invention is significantly improved.

[0029] (3) The present invention heat-treats polymer fibers in oxygen-containing gas, which can crosslink and cyclize some functional groups on the fiber surface, thereby improving the thermal stability and oxidation resistance of polymer fiber catalytic materials and solving the problems of poor thermal stability and poor oxidation resistance of manganese-based polymer fiber catalytic materials.

[0030] (4) The manganese-based fiber catalytic material prepared by the present invention has stable oxidation resistance, high thermal stability and excellent catalytic performance. In addition, there are no restrictions on the choice of morphology. It can be applied in any form such as random fiber, yarn, needle-punched cloth, knitted cloth, etc. It is not only convenient to fill, but also greatly expands the depth and breadth of application of catalytic materials.

[0031] (5) The preparation method of the manganese-based fiber catalytic material of the present invention is simple to operate and has mild conditions, and can be industrially promoted and applied. Attached Figure Description

[0032] Figure 1 SEM characterization images of the manganese-based fiber catalytic material and the precursor of the manganese-based fiber catalytic material prepared in Example 1 of the present invention; wherein, a1-a3 are morphological images of the precursor of the manganese-based fiber catalytic material at different microscales, and b1-b3 are morphological images of the manganese-based fiber catalytic material at different microscales.

[0033] Figure 2 The image shows the EDS surface scan results of the manganese-based fiber catalytic material prepared in Example 1 of this invention; where a1-a2 are surface scan images of Mn elements on the surface of the manganese-based fiber catalytic material precursor, and b1-b2 are surface scan images of Mn elements on the surface of the manganese-based fiber catalytic material.

[0034] Figure 3 Thermogravimetric analysis diagrams of fibers at each preparation stage in the preparation process of the manganese-based fiber catalytic material prepared in Example 1 of this invention;

[0035] Figure 4 The figure shows the results of the test on the effect of ozone activation time on the catalytic performance of manganese-based fiber materials. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0037] The following detailed description is exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0038] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, components, and / or combinations thereof.

[0039] Unless otherwise specified, the experimental methods in the following examples all employ conventional techniques in this technical field or follow the conditions recommended by the manufacturer; reagents or instruments whose manufacturers are not specified are all commercially available products.

[0040] Example 1:

[0041] A method for preparing a manganese-based fiber catalytic material, specifically comprising:

[0042] Commercial acrylic fibers were washed three times with deionized water and dried at 60°C to constant weight. 200 mL of triethylenetetramine was added to a three-necked flask, and 2 g of pretreated acrylic fibers were immersed in the triethylenetetramine for swelling at 60°C for 12 h. The temperature was then increased to 150°C and reacted for 3 h. After cooling, the fibers were washed and dried at 60°C to constant weight to obtain amino fibers, whose exchange capacity was measured to be 5.93 mmol / g. 1 g of the prepared amino fibers was placed in a tube furnace, and air was introduced into the furnace at 200 mL / min for equilibration for 30 min. The temperature was then increased to 200°C at 10°C / min and held for 4 h. After cooling, the fibers were sealed and stored. Pre-oxidized amine fibers were obtained. 0.5 g of the pre-oxidized amine fibers were placed in an Erlenmeyer flask containing 20 mL of a 100 mmol / L potassium permanganate solution and reacted at 40°C with shaking for 0.5 h. The flask was then removed, washed with water until the eluent was colorless, and dried at 60°C to constant weight to obtain the manganese-based fiber catalyst precursor. This precursor was then in-situ activated for 4 h in an ozone stream with an ozone concentration of 20 mg / L, a mass hourly space velocity of 1200000 mL / (g·h), and a temperature of 110°C to obtain the manganese-based fiber catalyst. The manganese content in this catalyst was determined to be 255.4 mg / g.

[0043] The manganese-based fiber catalyst and the manganese-based fiber catalyst precursor prepared in this embodiment were used to catalyze the ozone oxidation degradation of toluene in the gas. The degradation experimental conditions were: space velocity 120000 mL / (g·h), reaction temperature 90℃, toluene concentration in the gas 100 ppm, ozone concentration 4.0-4.5 mg / L, and gas humidity 0-10%. After the degradation reaction was completed, the toluene content in the gas was detected and the toluene removal rate was calculated.

[0044] Testing revealed that the manganese-based fiber catalytic material prepared in this embodiment achieved a 100% removal rate of toluene from the gas, with an inorganic carbon oxide selectivity greater than 99% in the product; while the manganese-based fiber catalytic material precursor achieved an 83% removal rate of toluene from the gas. This indicates that the catalytic performance of the manganese-based fiber catalytic material prepared in this invention is significantly higher than that of the manganese-based fiber catalytic material precursor without in-situ ozone activation treatment, and it can be used for catalytic ozone oxidation to degrade toluene pollutants in the gas.

[0045] The manganese-based fiber catalytic material and the manganese-based fiber catalytic material precursor prepared in this embodiment were characterized by SEM. The SEM characterization images are shown below. Figure 1 As shown.

[0046] Depend on Figure 1 It is evident that ozone activation resulted in fiber thinning, more clearly defined manganese oxide nanoparticles on the surface, and the formation of numerous pores. This indicates that the strong oxidizing power of high-concentration ozone and the strong catalytic effect of manganese oxide species on the fiber surface oxidized and stripped away organic debris covering the active manganese oxide species on the fiber catalyst, exposing the active manganese oxide species to the fiber surface. A certain degree of aggregation and agglomeration exists between adjacent nanoparticles on the fiber catalyst surface, and no clear boundary was observed between the nanoparticles and the fiber matrix, indicating that the manganese oxide particles (MnO)... x The fibers are connected by chemical bonds, and the stacking of manganese oxide nanoparticles is bonded by van der Waals forces.

[0047] EDS surface scanning was performed on the manganese-based fiber catalytic material prepared in this embodiment. The EDS surface scanning results are as follows: Figure 2 As shown.

[0048] Depend on Figure 2 It is evident that the manganese species on the surface of the manganese-based fiber catalytic material prepared by this invention are uniformly dispersed, confirming that the active species of manganese oxides are uniformly dispersed on the fiber surface with the assistance of functional groups. This also confirms that the prepared fiber catalytic material is a manganese-based catalyst. After ozone activation, the manganese density on the fiber catalyst surface significantly increases, indicating that the ozone activation process can effectively remove organic fragments covering the surface of the manganese oxide active species, increasing the number of exposed effective active species on the fiber surface and thus significantly improving its catalytic activity.

[0049] Thermogravimetric analysis was performed on the fibers at each stage of the preparation process of the manganese-based fiber catalytic material in this embodiment. The fibers at each stage include amine-based fibers (abbreviated as APANF), pre-oxidized amine-based fibers (abbreviated as TAPANF), and manganese-based fiber catalytic material precursors (abbreviated as MnO). x / TAPANF) and manganese-based fiber catalytic materials (abbreviated as oo -MnO x / TAPANF). Thermogravimetric analysis results are as follows: Figure 3 As shown.

[0050] Figure 3 This is a thermogravimetric analysis diagram of the fibers at each preparation stage during the preparation of the manganese-based fiber catalytic material in Example 1 of the present invention.

[0051] Depend on Figure 3It can be seen that APANF exhibits three weight loss plateaus. The first plateau is caused by the desorption of adsorbed water and gas on the fiber surface, and this plateau lasts until about 150 °C. The second plateau is caused by the removal of nitrogen-containing groups, and the third plateau is caused by the degradation of the fiber polymer backbone. After thermal oxidation, the second weight loss plateau of APANF is significantly weakened, and the initial weight loss temperature of the third plateau is also slightly delayed, indicating that the nitrogen-containing group structure becomes more stable during the thermal oxidation pretreatment, improving the thermal stability of the fiber. After loading with manganese oxide, MnO... x The second weight loss plateau of / TAPANF remained essentially unchanged, but the weight loss endpoint temperature shifted later, indicating that the loading of manganese oxides improved the thermal stability of the fiber; MnO x After the third weight loss plateau of / TAPANF, the residual weight of the fiber increased significantly, which was due to the loading of inorganic manganese oxides. After ozone activation... oo -MnO x The first weight loss plateau of the / TAPANF fiber was significantly weakened, while the second weight loss plateau remained basically unchanged, indicating that ozone activation further improved the thermal stability of the fiber.

[0052] Example 2:

[0053] A method for preparing a manganese-based fiber catalytic material, specifically comprising:

[0054] Commercial acrylic fibers were washed three times with deionized water and dried at 60°C to constant weight. 400 mL of diethylenetriamine solution (20% diethylenetriamine by mass, ethylene glycol as solvent) was added to a three-necked flask. 2 g of pretreated acrylic fibers were then weighed and immersed in the diethylenetriamine solution, swelling at 80°C for 4 hours. The temperature was then raised to 130°C and reacted for 5 hours. After cooling, washing, and drying at 60°C to constant weight, amino-based fibers were obtained. The exchange capacity was measured to be 4.05 mmol / g. 2g of the prepared amine fiber was placed in a tube furnace, and air was introduced into the tube furnace at 100 mL / min for equilibration for 30 min. The temperature was then increased to 250℃ at 20℃ / min and held for 0.5 h. After cooling, the mixture was sealed and stored to obtain pre-oxidized amine fiber. 1g of the pre-oxidized amine fiber was placed in an Erlenmeyer flask containing 200 mL of a 20 mmol / L potassium permanganate solution and reacted at 10℃ with shaking for 12 h. The flask was then removed, washed with water until the washings were colorless, and dried at 60℃ to constant weight to obtain the manganese-based fiber catalyst precursor. The manganese-based fiber catalyst precursor was in-situ activated for 2 h in an ozone stream with an ozone concentration of 30 mg / L, a mass hourly space velocity of 960,000 mL / (g·h), and a temperature of 120℃ to obtain the manganese-based fiber catalyst. The manganese content in this manganese-based fiber catalyst was determined to be 145.1 mg / g.

[0055] The manganese-based fiber catalyst and the manganese-based fiber catalyst precursor prepared in this embodiment were used to catalyze the ozone oxidation degradation of benzene in the gas. The degradation experimental conditions were: space velocity 120000 mL / (g·h), reaction temperature 90℃, benzene concentration in the gas 100 ppm, ozone concentration 4.0-4.5 mg / L, and gas humidity 0-10%. After the degradation reaction was completed, the benzene content in the gas was detected and the benzene removal rate was calculated.

[0056] Testing revealed that the manganese-based fiber catalytic material prepared in this embodiment achieved a benzene removal rate of 99.2% in the gas, with an inorganic carbon oxide selectivity of 98.5% in the product; while the manganese-based fiber catalytic material precursor achieved a benzene removal rate of 65%. This indicates that the catalytic performance of the manganese-based fiber catalytic material prepared in this invention is significantly higher than that of the manganese-based fiber catalytic material precursor without ozone in-situ activation treatment, and it can be used for catalytic ozone oxidation to degrade benzene pollutants in the gas.

[0057] Example 3:

[0058] A method for preparing a manganese-based fiber catalytic material, specifically comprising:

[0059] Commercial acrylic fibers were washed three times with deionized water and dried at 60°C to constant weight. 40 mL of ethylenediamine solution (40% ethylenediamine by mass, glycerol as solvent) was added to a three-necked flask. 2 g of pretreated acrylic fibers were then immersed in the ethylenediamine solution and swelled at 60°C for 12 h. The temperature was then raised to 100°C and reacted for 12 h. After cooling, washing, and drying at 60°C to constant weight, amino fibers were obtained, with an exchange capacity of 3.06 mmol / g. 1 g of the prepared amino fibers was immersed in a tube furnace, and air was introduced into the furnace at a rate of 500 mL / min. The mixture was allowed to stand for 30 minutes, then heated to 220℃ at a rate of 2℃ / min and held at that temperature for 2 hours. After cooling, it was sealed and stored to obtain pre-oxidized amine fibers. 1 g of the pre-oxidized amine fibers was placed in an Erlenmeyer flask containing 100 mL of a 50 mmol / L potassium permanganate solution and reacted at 25℃ with shaking for 6 hours. The flask was then removed, washed with water until the washings were colorless, and dried at 60℃ to constant weight to obtain the precursor of the manganese-based polymer fiber catalyst. This precursor was then in-situ activated for 6 hours in an ozone stream with an ozone concentration of 10 mg / L, a mass hourly space velocity of 480,000 mL / (g·h), and a temperature of 115℃ to obtain the manganese-based fiber catalyst. The manganese content in this catalyst was determined to be 105.2 mg / g.

[0060] The manganese-based fiber catalyst and the manganese-based fiber catalyst precursor prepared in this embodiment were used to catalyze the ozone oxidation degradation of toluene in the gas. The experimental conditions for toluene degradation were: space velocity 120,000 mL / (g·h), reaction temperature 100℃, toluene concentration in the gas 90 ppm, ozone concentration 4.0-4.5 mg / L, and gas humidity 0-10%. After the degradation reaction was completed, the toluene content in the gas was detected and the toluene removal rate was calculated.

[0061] Testing revealed that the manganese-based fiber catalytic material prepared in this embodiment achieved a 100% removal rate of toluene from the gas, with an inorganic carbon oxide selectivity greater than 99% in the product; while the manganese-based fiber catalytic material precursor achieved a 67% removal rate of toluene from the gas. This indicates that the catalytic performance of the manganese-based fiber catalytic material prepared in this invention is significantly higher than that of the manganese-based fiber catalytic material precursor without in-situ ozone activation treatment, and it can be used for catalytic ozone oxidation to degrade toluene pollutants in gases.

[0062] Example 4: Influence of in-situ ozone activation time on the catalytic performance of the prepared manganese-based fiber catalytic material:

[0063] To investigate the effect of ozone in-situ activation time on the catalytic performance of the prepared manganese-based fiber catalyst, the manganese-based fiber catalyst precursor prepared in Example 1 was subjected to ozone in-situ activation for different times in an ozone gas stream with an ozone concentration of 20 mg / L, a mass hourly space velocity (MHSV) of 1,200,000 mL / (g·h), and a temperature of 110 °C. Then, the manganese-based fiber catalysts obtained after different ozone in-situ activation times were used to catalyze the ozone oxidation and degradation of toluene in the gas. The toluene degradation experimental conditions were: MHSV of 9.6 × 10⁻⁶. 5 The reaction was carried out at a concentration of mL / (g·h) at a temperature of 110℃, with a toluene concentration of 100 ppm, an ozone concentration of 1000 ppm, and a humidity of 0-10%. After the degradation reaction was completed, the toluene content in the gas was measured and the toluene removal rate was calculated. The results are as follows: Figure 4 As shown.

[0064] Depend on Figure 4 It can be seen that in the first 180 minutes of the ozone in-situ activation process, when the manganese-based fiber catalytic material catalyzes the degradation of toluene in the gas, the toluene removal efficiency rapidly increases from 0.20 to 0.63, and the catalytic activity increases by more than 2 times. This indicates that the ozone activation process can significantly improve the catalytic activity of the fiber catalytic material. Moreover, the toluene removal efficiency does not significantly improve during the ozone in-situ activation process from 180 min to 420 min. Therefore, the preferred ozone in-situ activation time is 180 min.

[0065] Finally, it should be noted that the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may use the above technical content as inspiration to make changes or modifications. These are equivalent embodiments with variations. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical concept of the present invention still fall within the protection scope of the claims of the present invention.

Claims

1. A process for the preparation of a manganese-based fibrous catalytic material, characterized in that, Polymer fibers are pre-oxidized to obtain pre-oxidized polymer fibers; the pre-oxidized polymer fibers are in-situ oxidized by a potassium permanganate in-situ oxidation method to obtain a manganese-based polymer fiber catalytic material precursor; the manganese-based polymer fiber catalytic material precursor is in-situ activated by an ozone gas flow to obtain a manganese-based fiber catalytic material; the temperature of the in-situ activation by the ozone is 110-130 ℃, and the time is 2-8 h; the concentration of ozone in the ozone gas flow is 10-40 mg / L, the mass space velocity of the ozone gas flow during the in-situ activation by the ozone is 240000-1200000 mL / (g·h); the polymer fibers are acrylic fibers or modified acrylic fibers; the modified acrylic fibers are acrylic fibers grafted with amine groups, and the amine groups are grafted on the acrylic fibers by reacting polyamine compounds with-CN groups in the acrylic fibers.

2. The production method according to claim 1, characterized by, The specific operation of in-situ oxidizing the pre-oxidized polymer fibers by the potassium permanganate in-situ oxidation method is as follows: the pre-oxidized polymer fibers are added into a potassium permanganate solution for oxidation reaction, and after the reaction is completed, the polymer fibers are collected, washed, and dried to obtain the manganese-based polymer fiber catalytic material precursor.

3. The production method according to claim 2, characterized by, The concentration of the potassium permanganate solution is 20-100 mmol / L, the liquid-solid ratio of the potassium permanganate solution to the pre-oxidized polymer fibers is (20-200) mL:1 g, the temperature of the oxidation reaction is 10-40 ℃, and the time of the oxidation reaction is 0.5-12 h.

4. The production method according to any one of claims 1 to 3, characterized by, The pre-oxidation treatment specifically comprises: heat treating the polymer fibers in an oxygen-containing gas; the temperature of the heat treatment is 200-250 ℃, and the time of the heat treatment is 0.5-4 h; and the flow rate of the oxygen-containing gas is 100-500 mL / min. 5.A manganese-based fiber catalytic material prepared by the preparation method of any one of claims 1-4.

6. The manganese-based fibrous catalytic material according to claim 5, characterized in that, The morphology of the manganese-based fiber catalytic material is one or more of fiber, wool, needle-punched cloth, and knitted cloth. 7.The manganese-based fiber catalytic material of claim 5 or 6 is used in a catalyst.

8. Use according to claim 7, characterized in that, The catalyst is a catalyst used in an ozone oxidation process; the ozone oxidation comprises ozone oxidation degradation of benzene series in a gas phase; the benzene series comprises toluene and / or benzene; and the temperature of the degradation is 70-110 ℃.

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