Continuous preparation of metal-doped active manganese based on microfluidic control, preparation method and application thereof

Abstract

The application discloses a kind of metal-doped active manganese based on microflow control continuous preparation and preparation method and application, it is related to the field of aldehyde removal and odor removal.The method for metal-doped active manganese based on microflow control continuous preparation includes the following steps: potassium permanganate solution, manganese sulfate solution and ammonium bicarbonate solution are respectively sent into microflow reaction kettle, temperature is controlled to be 60~150 ℃, reaction is carried out, filtration is carried out, and metal ion-ammonium ion-doped δ-type manganese dioxide solid is obtained.Dried δ-type manganese dioxide solid at temperature not more than 150 ℃, and metal-doped active manganese is obtained.The specific surface area and pore volume of the metal-doped active manganese prepared in the application are larger, and the ratio of the atomic content of trivalent manganese ions and tetravalent manganese ions is higher.The metal-doped active manganese has excellent catalytic odor removal performance.

Description

Technical Field

[0001] This application relates to the field of formaldehyde and odor removal, and in particular to a method for the continuous preparation of metal-doped active manganese based on microfluidic control, and its application. Background Technology

[0002] With the rapid development of my country's automobile industry and the improvement of people's living standards, automobiles have become one of the most important means of transportation for daily travel. As the number of vehicles in cities increases and travel needs grow, people are spending more and more time inside their cars, making in-vehicle pollutants a significant factor affecting human health. In-vehicle pollutants mainly originate from interior materials and external pollutants.

[0003] Solvents (such as toluene, xylene, and benzene) used in the production and assembly of materials used in vehicles, such as plastics, synthetic leather, carpets, and dashboards, can be slowly released into the vehicle, forming pollutants. During vehicle use, VOCs (volatile organic compounds) from outside the vehicle can enter the cabin through the ventilation system, also contributing to the pollution. The confined and relatively enclosed space inside a vehicle can easily cause dizziness, drowsiness, feelings of oppression, irritability, and difficulty concentrating for passengers over extended periods, harming their health. Therefore, controlling the concentration of pollutants inside the vehicle is essential to providing a safe, healthy, and comfortable riding environment.

[0004] Currently, manganese dioxide is commonly used to remove odors and volatile organic compounds from vehicle interiors. In the traditional hydrothermal / precipitation method for synthesizing manganese dioxide, potassium permanganate solution and manganese sulfate solution are added to the reactor simultaneously, the reaction temperature is controlled, and the mixture is filtered after the reaction to obtain the manganese dioxide product. However, the concentrations of materials and products, as well as the chemical reaction rate, all change over time, making the reaction process difficult to control and regulate. This can easily lead to problems such as particle agglomeration and uncontrollable crystal structure, resulting in manganese dioxide with fewer active sites and a lower specific surface area, thus affecting its catalytic deodorization performance. Furthermore, the traditional hydrothermal / precipitation method for synthesizing manganese dioxide employs an intermittent production process, resulting in low production efficiency. Summary of the Invention

[0005] The main objective of this application is to propose a method for the continuous preparation of metal-doped active manganese based on microfluidic control, and its application, aiming to solve the problems of low active sites, low specific surface area, and low production efficiency of manganese dioxide prepared by existing technologies.

[0006] In a first aspect, this application provides a method for the continuous preparation of metal-doped active manganese based on microfluidic control, comprising the following steps: S1. Provides potassium permanganate solution, manganese sulfate solution and ammonium bicarbonate solution, wherein the manganese sulfate solution contains metal doped ions, and the metal doped ions include at least one of ferrous ions, copper ions, zinc ions and cobalt ions; S2. The potassium permanganate solution, manganese sulfate solution and ammonium bicarbonate solution provided in step S1 are each independently fed into a microfluidic reactor and reacted at a temperature of 60~150℃ to obtain the reaction products. S3. Filter the reaction product obtained in step S2 to obtain a metal ion-ammonium ion-doped δ-type manganese dioxide solid. Dry the δ-type manganese dioxide solid at a temperature not exceeding 150°C to obtain metal-doped active manganese.

[0007] By employing the above technical solution, potassium permanganate solution, manganese sulfate solution, and ammonium bicarbonate solution are separately fed into a microfluidic reactor. The microfluidic reactor offers advantages such as small size, rapid heat / mass transfer, and easy control of the reaction process. The potassium permanganate solution, manganese sulfate solution, and ammonium bicarbonate solution are mixed within the microchannels of the microfluidic reactor. The turbulence within the microchannels facilitates thorough mixing and reaction of the materials. The temperature of the materials within the microchannels is controlled at 60–150°C, resulting in a reaction that generates delta-type manganese dioxide. Metal dopant ions and ammonium ions can then enter the lamellar structure of delta-type manganese dioxide through mechanisms such as ion exchange, altering the crystal lattice structure of the delta-type manganese dioxide, forming more voids, increasing the specific surface area of ​​the material, and improving its catalytic deodorization performance.

[0008] Drying the δ-type manganese dioxide solid doped with ammonium ions generated during the reaction at a temperature not exceeding 150℃ can effectively remove water adsorbed on the material surface. Furthermore, during the high-temperature drying process, the ammonium ions (NH4+) interspersed between the manganese dioxide layers release moisture. + It is decomposed into ammonia (NH3) and hydrogen ions (H2O). + NH3 escapes from the layered structure. The remaining H... + It can release nearby tetravalent manganese ions (Mn) 4+ ) reduced to trivalent manganese ions (Mn 3+ ), increased trivalent manganese ions (Mn) 3+ The content of NH4 helps to increase the active sites of the material, and because of the high content of NH4 + The decomposition of the material forms more micropores, increasing the specific surface area of ​​the material and significantly improving its catalytic deodorization performance.

[0009] The technical solution of this application employs microfluidic control to achieve thorough mixing and reaction between materials, resulting in high reaction efficiency, complete reaction, and controllable reaction process, enabling continuous production and improving production efficiency. In the microfluidic reactor, the materials react to generate δ-type manganese dioxide solid doped with metal ions—ammonium ions. During the high-temperature drying process, NH4... + The decomposition of H+ forms more micropores, which helps to increase the specific surface area of ​​the material, and the H+ produced by the decomposition... +can be nearby Mn 4+ Reduce to Mn 3+ Increased Mn 3+ The increased content of [specific element] creates more active sites, thereby improving the catalytic deodorization performance of the material.

[0010] Optionally, in step S2, potassium permanganate solution, manganese sulfate solution and ammonium bicarbonate solution are each independently fed into the microfluidic reactor at a flow rate of 2~5 mL / min, and the molar ratio of potassium permanganate, manganese sulfate, metal dopant ions and ammonium bicarbonate fed into the microfluidic reactor is 2:3:(0.18~2.34):(2.8~8.0).

[0011] By adopting the above technical solution, the potassium permanganate solution, manganese sulfate solution, and ammonium bicarbonate solution are each introduced into the microchannel of the microfluidic reactor at a flow rate of 2-5 mL / min. This ensures thorough mixing and reaction of the materials, makes the entire reaction process controllable, enables continuous production, and improves reaction efficiency. Furthermore, by controlling the molar ratio of potassium permanganate, manganese sulfate, metal dopant ions, and ammonium bicarbonate fed into the microfluidic reactor, the full reaction between the materials is promoted, ensuring an appropriate concentration of metal ions and ammonium ions. This effectively increases the active sites and specific surface area of ​​the materials, thereby improving their catalytic deodorization performance.

[0012] Preferably, in step S2, the molar ratio of potassium permanganate, manganese sulfate, metal dopant ions and ammonium bicarbonate fed into the microfluidic reactor is 2:3:(1.05~1.50):(4~6).

[0013] By adopting the above technical solution, and by further optimizing the molar ratio of potassium permanganate, manganese sulfate, metal dopant ions and ammonium bicarbonate fed into the microfluidic reactor, the active sites and specific surface area of ​​the material can be further improved, thereby effectively improving the catalytic deodorization performance of the material.

[0014] Optionally, in step S3, drying the δ-type manganese dioxide solid at a temperature not exceeding 150°C includes: drying the δ-type manganese dioxide solid at a temperature not exceeding 100°C for 1-3 hours, and drying at a temperature not exceeding 150°C for 1-3 hours.

[0015] By adopting the above technical solution, the δ-type manganese dioxide solid is first dried at a temperature not exceeding 100°C to remove adsorbed water on the surface of the material. Then, it is further dried at a temperature not exceeding 150°C to promote the more complete decomposition of ammonium ions, increase the active sites and specific surface area of ​​the material, and improve the catalytic deodorization performance of the material.

[0016] In the technical solution of this application, by combining low-temperature drying with high-temperature drying, the ammonium ions interpenetrating between manganese dioxide layers can be decomposed more fully, thereby obtaining a material with more active sites and a larger specific surface area, thus endowing the material with excellent catalytic deodorization performance.

[0017] Optionally, in step S3, drying the δ-type manganese dioxide solid at a temperature not exceeding 150°C includes: drying the δ-type manganese dioxide solid at a temperature of 60~70°C for 1~3 hours, and drying at a temperature of 130~140°C for 1~3 hours.

[0018] By adopting the above technical solution and further optimizing the drying temperature of δ-type manganese dioxide solid, the catalytic deodorization performance of the prepared material can be further improved.

[0019] Preferably, in step S3, drying the δ-type manganese dioxide solid at a temperature not exceeding 150°C includes: drying the δ-type manganese dioxide solid at a temperature of 60~70°C for 2 hours, and drying it at a temperature of 130~140°C for 2 hours.

[0020] Optionally, in step S2, the temperature is controlled at 70~90℃ to carry out the reaction and obtain the reaction product.

[0021] By adopting the above technical solution, after mixing potassium permanganate solution, manganese sulfate solution and ammonium bicarbonate solution, the temperature of the mixed liquid in the microchannel of the microfluidic reactor is controlled at 70~90℃, which ensures the generation of δ-type manganese dioxide with low energy consumption.

[0022] Optionally, in step S1, the method for preparing the manganese sulfate solution includes: adding manganese sulfate, sulfate containing metal doping ions, and surfactant to water, stirring and mixing thoroughly to obtain a manganese sulfate solution, wherein the sulfate is selected from at least one of ferrous sulfate, copper sulfate, zinc sulfate, and cobalt sulfate.

[0023] Understandably, if the sulfate is ferrous sulfate, the preparation method of manganese sulfate solution includes: adding manganese sulfate, ferrous sulfate, and a surfactant to water, stirring, and mixing thoroughly to obtain the manganese sulfate solution. Similarly, if other sulfates are used, the preparation method is the same as that for ferrous sulfate, and will not be repeated here.

[0024] The surfactant may be cetyltrimethylammonium bromide (CTAB), or other types of surfactant may be used as needed, and this application does not impose any restrictions.

[0025] Secondly, the metal-doped active manganese provided in this application is prepared by the method for continuous preparation of metal-doped active manganese based on microfluidic control as described in any of the above claims.

[0026] Optionally, the specific surface area of ​​the metal-doped active manganese is ≥260 m². 2 / g, pore volume ≥0.35cm 3 / g, and in the metal-doped active manganese, the atomic ratio of trivalent manganese ions to tetravalent manganese ions is (0.35~0.50):1.

[0027] By employing the above technical solution and the method for continuous preparation of metal-doped active manganese based on microfluidic control, the obtained metal-doped active manganese exhibits a large specific surface area and pore volume, as well as a high ratio of trivalent to tetravalent manganese ions. This metal-doped active manganese demonstrates excellent catalytic deodorization performance.

[0028] Preferably, the specific surface area of ​​the metal-doped active manganese is 260~300m². 2 / g, pore volume 0.35~0.50cm³ 3 / g.

[0029] Thirdly, the application of the aforementioned metal-doped active manganese in formaldehyde and odor removal provided in this application.

[0030] By adopting the above technical solution, metal-doped active manganese with a large specific surface area and pore volume and a high ratio of trivalent manganese ion to tetravalent manganese ion atomic content can achieve a high removal rate for formaldehyde, acetaldehyde, and xylene, and also has a good removal effect on odorous gases.

[0031] In summary, this application includes at least one of the following beneficial technical effects: 1. The technical solution of this application employs microfluidic control to achieve thorough mixing and reaction between materials, resulting in high reaction efficiency, complete reaction, and controllable reaction process, enabling continuous production and improving reaction production efficiency. In the microfluidic reactor, the materials react to generate δ-type manganese dioxide solid doped with metal ions—ammonium ions. During the high-temperature drying process, NH4... + The decomposition of H+ forms more micropores, which helps to increase the specific surface area of ​​the material, and the H+ produced by the decomposition... + can be nearby Mn 4+ Reduce to Mn 3+ Increased Mn 3+ The increased content of [specific element] creates more active sites, thereby improving the catalytic deodorization performance of the material.

[0032] 2. The method for continuous preparation of metal-doped active manganese based on microfluidic control provided in this application yields metal-doped active manganese with a large specific surface area and pore volume, and a high ratio of trivalent to tetravalent manganese ions. This metal-doped active manganese exhibits high removal rates for formaldehyde, acetaldehyde, and xylene. Attached Figure Description

[0033] Figure 1 This is a scanning electron microscope (SEM) image of the active manganese prepared in Example 1 of this application; Figure 2 This is a scanning electron microscope (SEM) image of the active manganese prepared in Comparative Example 1 of this application; Figure 3 This is an X-ray diffraction (XRD) pattern of the active manganese prepared in Example 1 and Comparative Example 1 of this application. Detailed Implementation

[0034] The present application will be further described in detail below with reference to the embodiments. Example 1

[0035] A method for continuous preparation of metal-doped active manganese based on microfluidic control includes the following steps: S1. Provide potassium permanganate solution, manganese sulfate solution and ammonium bicarbonate solution.

[0036] (1) Preparation of potassium permanganate solution: Add potassium permanganate to deionized water and stir to mix thoroughly to obtain a potassium permanganate solution with a molar concentration of 0.05 mol / L.

[0037] (2) Preparation of manganese sulfate solution: Manganese sulfate, ferrous sulfate and hexadecyltrimethylammonium bromide were added to deionized water and stirred thoroughly to obtain manganese sulfate solution. The molar concentration of manganese sulfate in the prepared manganese sulfate solution was 0.1 mol / L, the molar concentration of ferrous sulfate was 0.05 mol / L, and the molar concentration of hexadecyltrimethylammonium bromide was 0.05 mol / L.

[0038] (3) Preparation of ammonium bicarbonate solution: Add ammonium bicarbonate to deionized water and stir to mix thoroughly to obtain an ammonium bicarbonate solution with a molar concentration of 0.15 mol / L.

[0039] S2. Potassium permanganate solution, manganese sulfate solution, and ammonium bicarbonate solution are simultaneously added to the microfluidic reactor at a feed rate of 4 mL / min, 3 mL / min, and 4 mL / min, respectively. The potassium permanganate solution, manganese sulfate solution, and ammonium bicarbonate solution are mixed in the microchannel (200 μm wide, 100 μm deep, and 19 mm in total length) of the microfluidic reactor. The temperature of the microchannel is controlled at 80 °C. The materials in the microchannel react with each other, and the resulting reaction product is sent to the product collection tank through an insulated pipe.

[0040] S3. Filter the reaction product obtained in step S2 to obtain a metal ion-ammonium ion doped δ-type manganese dioxide solid. Dry the δ-type manganese dioxide solid at 150°C for 4 hours to obtain metal-doped active manganese.

[0041] Examples 2-4

[0042] This embodiment is based on Example 1, the difference being that: in step S1 (2), the molar concentration of ferrous sulfate in the manganese sulfate solution changes, and in step (3), the molar concentration of ammonium bicarbonate solution changes; the other steps remain the same as in Example 1. Specifically, In Example 2, the molar concentration of ferrous sulfate in the manganese sulfate solution was 0.006 mol / L, and the molar concentration of ammonium bicarbonate solution was 0.07 mol / L.

[0043] In Example 3, the molar concentration of ferrous sulfate in the manganese sulfate solution was 0.035 mol / L, and the molar concentration of ammonium bicarbonate solution was 0.1 mol / L.

[0044] In Example 4, the molar concentration of ferrous sulfate in the manganese sulfate solution was 0.078 mol / L, and the molar concentration of ammonium bicarbonate solution was 0.2 mol / L.

[0045] Examples 5-6

[0046] Examples 5 and 6 are based on Example 1, the difference being that in step S1 (2), different metal ions are doped when preparing the manganese sulfate solution; the other steps remain the same as in Example 1. Specifically, In Example 5, the manganese sulfate solution was prepared by adding manganese sulfate, copper sulfate pentahydrate, and hexadecyltrimethylammonium bromide to deionized water and stirring until fully mixed to obtain a manganese sulfate solution. The molar concentration of manganese sulfate in the prepared manganese sulfate solution was 0.1 mol / L, the molar concentration of copper sulfate pentahydrate was 0.05 mol / L, and the molar concentration of hexadecyltrimethylammonium bromide was 0.05 mol / L.

[0047] In Example 6, the manganese sulfate solution was prepared by adding manganese sulfate, cobalt sulfate heptahydrate, and hexadecyltrimethylammonium bromide to deionized water and stirring until fully mixed to obtain a manganese sulfate solution. The molar concentration of manganese sulfate in the prepared manganese sulfate solution was 0.1 mol / L, the molar concentration of cobalt sulfate heptahydrate was 0.05 mol / L, and the molar concentration of hexadecyltrimethylammonium bromide was 0.05 mol / L. Example 7

[0048] This embodiment is based on Embodiment 1, the difference being that in step S3, the temperature and time for drying the δ-type manganese dioxide solid have changed, while the other steps remain the same as in Embodiment 1. Specifically, In Example 7, δ-type manganese dioxide solid was dried at 60°C for 2 hours and then dried at 130°C for 2 hours to obtain metal-doped active manganese. Comparative Example 1

[0049] A method for continuous preparation of active manganese based on microfluidic control includes the following steps: S1. Provide potassium permanganate solution, manganese sulfate solution and sodium bicarbonate solution.

[0050] (1) Preparation of potassium permanganate solution: Add potassium permanganate to deionized water and stir to mix thoroughly to obtain a potassium permanganate solution with a molar concentration of 0.05 mol / L.

[0051] (2) Preparation of manganese sulfate solution: Manganese sulfate and hexadecyltrimethylammonium bromide were added to deionized water and stirred thoroughly to obtain manganese sulfate solution. The molar concentration of manganese sulfate in the prepared manganese sulfate solution was 0.1 mol / L and the molar concentration of hexadecyltrimethylammonium bromide was 0.05 mol / L.

[0052] (3) Preparation of sodium bicarbonate solution: Sodium bicarbonate was added to deionized water and stirred thoroughly to obtain a sodium bicarbonate solution with a molar concentration of 0.15 mol / L.

[0053] S2. Potassium permanganate solution, manganese sulfate solution, and sodium bicarbonate solution are simultaneously added to the microfluidic reactor at a feed rate of 4 mL / min, 3 mL / min, and 4 mL / min, respectively. The potassium permanganate solution, manganese sulfate solution, and sodium bicarbonate solution are mixed in the microchannel (200 μm wide, 100 μm deep, and 19 mm in total length) of the microfluidic reactor. The temperature of the microchannel is controlled at 80 °C. The materials in the microchannel react with each other, and the resulting reaction products are sent to the product collection tank through the insulated pipe.

[0054] S3. Filter the reaction product obtained in step S2 to obtain δ-type manganese dioxide solid. Dry the δ-type manganese dioxide solid at 70°C for 4 hours to obtain manganese dioxide product. S4. Add the manganese dioxide product obtained in step S3 to a 0.5 mol / L ammonia solution, control the solution temperature at 60℃, stir at 200 rpm for 12 hours, filter, dry the filtered solid at 70℃ for 4 hours, then add it to a 0.1 mol / L ferrous sulfate solution, stir at 200 rpm for 12 hours, filter, and dry the filtered solid at 70℃ for 4 hours to obtain active manganese. The ratio of the mass of the manganese dioxide product, the volume of the ammonia solution, and the volume of the ferrous sulfate solution is 1.0 g : 50 mL : 50 mL. Comparative Example 2

[0055] A method for continuous preparation of metal-doped active manganese based on microfluidic control includes the following steps: S1. Provide potassium permanganate solution, manganese sulfate solution and sodium bicarbonate solution.

[0056] (1) Preparation of potassium permanganate solution: Add potassium permanganate to deionized water and stir to mix thoroughly to obtain a potassium permanganate solution with a molar concentration of 0.05 mol / L.

[0057] (2) Preparation of manganese sulfate solution: Manganese sulfate, ferrous sulfate and hexadecyltrimethylammonium bromide were added to deionized water and stirred thoroughly to obtain manganese sulfate solution. The molar concentration of manganese sulfate in the prepared manganese sulfate solution was 0.1 mol / L, the molar concentration of ferrous sulfate was 0.05 mol / L, and the molar concentration of hexadecyltrimethylammonium bromide was 0.05 mol / L.

[0058] (3) Preparation of sodium bicarbonate solution: Sodium bicarbonate was added to deionized water and stirred thoroughly to obtain a sodium ammonium carbonate solution with a molar concentration of 0.15 mol / L.

[0059] S2. Potassium permanganate solution, manganese sulfate solution, and sodium bicarbonate solution are simultaneously added to the microfluidic reactor at a feed rate of 4 mL / min, 3 mL / min, and 4 mL / min, respectively. The potassium permanganate solution, manganese sulfate solution, and sodium bicarbonate solution are mixed in the microchannel (200 μm wide, 100 μm deep, and 19 mm in total length) of the microfluidic reactor. The temperature of the microchannel is controlled at 80 °C. The materials in the microchannel react with each other, and the resulting reaction products are sent to the product collection tank through the insulated pipe.

[0060] S3. Filter the reaction product obtained in step S2 to obtain metal ion-doped δ-type manganese dioxide solid. Dry the δ-type manganese dioxide solid at 100°C for 4 hours to obtain metal-doped active manganese. Comparative Example 3

[0061] A method for continuous preparation of active manganese based on microfluidic control includes the following steps: S1. Provide potassium permanganate solution, manganese sulfate solution and ammonium bicarbonate solution.

[0062] (1) Preparation of potassium permanganate solution: Add potassium permanganate to deionized water and stir to mix thoroughly to obtain a potassium permanganate solution with a molar concentration of 0.05 mol / L.

[0063] (2) Preparation of manganese sulfate solution: Manganese sulfate and hexadecyltrimethylammonium bromide were added to deionized water and stirred thoroughly to obtain manganese sulfate solution. The molar concentration of manganese sulfate in the prepared manganese sulfate solution was 0.1 mol / L and the molar concentration of hexadecyltrimethylammonium bromide was 0.05 mol / L.

[0064] (3) Preparation of ammonium bicarbonate solution: Add ammonium bicarbonate to deionized water and stir to mix thoroughly to obtain an ammonium bicarbonate solution with a molar concentration of 0.15 mol / L.

[0065] S2. Potassium permanganate solution, manganese sulfate solution, and ammonium bicarbonate solution are simultaneously added to the microfluidic reactor at a feed rate of 4 mL / min, 3 mL / min, and 4 mL / min, respectively. The potassium permanganate solution, manganese sulfate solution, and ammonium bicarbonate solution are mixed in the microchannel (200 μm wide, 100 μm deep, and 19 mm in total length) of the microfluidic reactor. The temperature of the microchannel is controlled at 80 °C. The materials in the microchannel react with each other, and the resulting reaction product is sent to the product collection tank through an insulated pipe.

[0066] S3. Filter the reaction product obtained in step S2 to obtain δ-type manganese dioxide solid. Dry the δ-type manganese dioxide solid at 150°C for 4 hours to obtain active manganese.

[0067] Performance Test 1

[0068] The scanning electron microscope (SEM) image of the metal-doped active manganese prepared in Example 1 is shown below. Figure 1 As shown; the scanning electron microscope (SEM) image of the active manganese prepared in Comparative Example 1 is shown below. Figure 2 As shown. The X-ray diffraction (XRD) patterns of the active manganese prepared in Example 1 and Comparative Example 1 are shown below. Figure 3 As shown.

[0069] Performance Test 2

[0070] The specific surface area and pore volume of the active manganese prepared in Examples 1-7 and Comparative Examples 1-3 were obtained using BET, and the surface atomic percentage of the active manganese prepared in Examples 1-7 and Comparative Examples 1-3 was obtained using XPS. The results are shown in Table 1 below. Among them, Mn 3+ / Mn 4+ This refers to the percentage of surface atoms of trivalent manganese ions versus tetravalent manganese ions.

[0071] Table 1. Specific surface area, pore volume, and surface atomic percentage

[0072] Performance Test 3

[0073] The activated manganese obtained in Examples 1-7 and Comparative Examples 1-3 was used to make odor-removing felt. The manufacturing process is as follows: Activated manganese and water-based polyacrylic acid resin (viscosity 8000 cps / 25℃) were mixed at a mass ratio of 5:1 and stirred thoroughly to obtain a viscous suspension. The viscous suspension was then uniformly coated onto a non-woven fabric (length 220 mm, width 145 mm, basis weight 80 g / m²). 2 After coating, the mass ratio of the nonwoven fabric loaded with the viscous suspension to the nonwoven fabric without the viscous suspension is 2:1. After drying, the deodorizing felt is obtained.

[0074] Removal experiments of formaldehyde, acetaldehyde, and xylene: at 1m 3 Inside the experimental chamber, two deodorizing mats were placed, followed by the addition of 3.8 μL of a 36 wt% formaldehyde solution, 2.2 μL of a 40 wt% acetaldehyde solution, and 2.3 μL of a 99 wt% xylene solution. The chamber was then heated to allow the formaldehyde, acetaldehyde, and xylene to evaporate. The concentration of the gases inside the chamber was measured using a detector. The formaldehyde concentration was set at 1 mg / m³. 3 When (ρ0) is reached, the experiment begins timing. After 24 hours, the concentration of the gas in the experimental chamber is measured again (ρ). 甲醛 ρ 乙醛 and ρ 二甲苯 The removal rates of formaldehyde, acetaldehyde, and xylene were obtained, and the results are shown in Table 2 below.

[0075] Wherein, formaldehyde removal rate = [(ρ0-ρ...]] 甲醛 ) / ρ0]×100%; Acetaldehyde removal rate = [(ρ1-ρ2)] 乙醛 ) / ρ1]×100%; Xylene removal rate = [(ρ2-ρ 二甲苯 ) / ρ2]×100%.

[0076] In the formula, ρ1 refers to the initial concentration of formaldehyde detected as 1 mg / m³. 3 Start timing; the concentration of acetaldehyde detected at this point is ρ2, which is also the corresponding concentration of xylene at this time. 甲醛 ρ 乙醛 ρ 二甲苯 The units for ρ1 and ρ2 are both mg / m³.3 .

[0077] Table 2 Removal rates of formaldehyde, acetaldehyde, and xylene

[0078] As shown in Tables 1 and 2, the experimental results obtained by the microfluidic-controlled continuous preparation method of metal-doped active manganese provided in this application produce metal-doped active manganese with a large specific surface area and pore volume, and a high ratio of trivalent to tetravalent manganese ions. This metal-doped active manganese exhibits high removal rates for formaldehyde, acetaldehyde, and xylene.

[0079] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure and principles of this application should be covered within the scope of protection of this application.

Claims

1. A method for continuous production of metal-doped active manganese based on microfluidic control, characterized by, The method comprises the following steps: S1, providing a potassium permanganate solution, a manganese sulfate solution and an ammonium bicarbonate solution, wherein the manganese sulfate solution contains metal doping ions, and the metal doping ions include at least one of ferrous ions, copper ions, zinc ions and cobalt ions; S2, independently feeding the potassium permanganate solution, the manganese sulfate solution and the ammonium bicarbonate solution provided in step S1 into a micro-flow reaction kettle to react at a temperature of 60-150 DEG C to obtain a reaction product; S3, filtering the reaction product obtained in step S2 to obtain a metal ion-ammonium ion doped δ-type manganese dioxide solid, and drying the δ-type manganese dioxide solid at a temperature not higher than 150 DEG C to obtain metal-doped active manganese; In step S2, the potassium permanganate solution, the manganese sulfate solution and the ammonium bicarbonate solution are independently fed into the micro-flow reaction kettle at a flow rate of 2-5 mL / min, and the molar ratio of potassium permanganate, manganese sulfate, metal doping ions and ammonium bicarbonate fed into the micro-flow reaction kettle is 2:3:(0.18-2.34):(2.8-8.0); In step S2, the molar ratio of potassium permanganate, manganese sulfate, metal doping ions and ammonium bicarbonate fed into the micro-flow reaction kettle is 2:3:(1.05-1.50):(4-6). In step S3, drying the δ-type manganese dioxide solid at a temperature not higher than 150 DEG C comprises: drying the δ-type manganese dioxide solid at a temperature not higher than 100 DEG C for 1-3 h, and drying the δ-type manganese dioxide solid at a temperature not higher than 150 DEG C for 1-3 h. The specific surface area of the metal-doped active manganese is ≥260 m 2 / g, and the pore volume is ≥0.35 cm 3 / g, and the surface atom percentage of trivalent manganese ions to tetravalent manganese ions in the metal-doped active manganese is (0.35~0.50):

1.

2. The method for continuous production of metal-doped active manganese based on microfluidic control according to claim 1, characterized in that, In step S3, drying the δ-type manganese dioxide solid at a temperature not higher than 150 DEG C comprises: drying the δ-type manganese dioxide solid at a temperature of 60-70 DEG C for 1-3 h, and drying the δ-type manganese dioxide solid at a temperature of 130-140 DEG C for 1-3 h.

3. The method for continuous production of metal-doped active manganese based on microfluidic control according to claim 1, characterized in that, In step S2, the temperature is controlled at 70-90 DEG C to react to obtain the reaction product.

4. The method for continuous production of metal-doped active manganese based on microfluidic control according to claim 3, characterized in that, In step S1, the preparation method of the manganese sulfate solution comprises: adding manganese sulfate, a sulfate salt containing metal doping ions and a surfactant into water, and stirring to fully mix to obtain the manganese sulfate solution, wherein the sulfate salt is at least one of ferrous sulfate, copper sulfate, zinc sulfate and cobalt sulfate.

5. The method for continuous production of metal-doped active manganese based on microfluidic control according to claim 1, characterized in that, The metal-doped active manganese is prepared by the method according to any one of claims 1-6.

6. The method for continuous production of metal-doped active manganese based on microfluidic control according to claim 1, characterized in that, 8. Use of the metal-doped active manganese according to claim 7 in de-aldehyde and de-odor.

7. A metal-doped active manganese characterized in that, ​ ​

Images