Active manganese formaldehyde decomposition sheet and preparation method thereof

Abstract

The invention relates to the technical field of formaldehyde removal, and provides an active manganese formaldehyde decomposition sheet and a preparation method thereof. The active manganese mixed glue comprises the following raw materials in parts by weight: 20-30 parts of an active manganese catalyst, 4-8 parts of a binder, 0.5-3 parts of a dispersant and 50-70 parts of deionized water; and the carrier is a PET non-woven fabric. The active manganese formaldehyde decomposition sheet provided by the invention has the performance of efficiently decomposing and removing formaldehyde.

Description

Technical Field

[0001] This invention relates to the field of formaldehyde removal technology, and in particular to an active manganese formaldehyde decomposition tablet and its preparation method. Background Technology

[0002] Formaldehyde is one of the most common indoor air pollutants, mainly originating from building materials, furniture, and tobacco smoke. Long-term exposure to low concentrations of formaldehyde may lead to respiratory diseases, allergic reactions, and even increase the risk of cancer. Therefore, in recent years, with the increasing awareness of environmental protection and health, more and more formaldehyde removal products have been developed by researchers and launched on the market.

[0003] Currently, formaldehyde removal is mainly addressed from two perspectives: adsorption and decomposition. For adsorption, common methods include using green plants and activated carbon, but these substances have limited absorption capacity for formaldehyde. Compared to adsorption, decomposition can completely remove formaldehyde. Decomposition primarily relies on adding catalysts to break down formaldehyde, typically using precious metals and metal oxides. Precious metals commonly used include Pd, Au, Ag, and Pt, but these are expensive. Researchers have discovered that activated manganese oxide, a catalyst with manganese dioxide as its main component, possesses unique catalytic properties, enabling highly efficient decomposition of formaldehyde into harmless carbon dioxide and water. This effectively reduces the concentration of formaldehyde and other organic pollutants in indoor environments, creating a healthy and comfortable living and working environment. Based on this, the concept of activated manganese decomposition tablets has gradually emerged in recent years.

[0004] Although manganese dioxide has the advantages of high cost-effectiveness and good formaldehyde decomposition effect, its catalytic activity and stability still need to be improved. For example, the catalytic activity of manganese dioxide is greatly affected by temperature, and the reaction rate is slow at room temperature, which is difficult to meet the needs of rapid formaldehyde removal. In addition, the active sites of manganese dioxide are easily covered by reaction products, which leads to catalyst deactivation.

[0005] Patent CN 116371359 A discloses a formaldehyde adsorbent containing activated manganese and its preparation method. The formaldehyde adsorbent prepared by this application includes loaded activated manganese powdered carbon, powdered carbon, binder and water. This application utilizes the catalytic oxidation function of manganese oxide to decompose formaldehyde and combines it with the physical adsorption of activated carbon, which can effectively improve the formaldehyde removal rate. However, this application does not solve the problem of insufficient catalytic activity and stability of the prepared manganese dioxide itself, and there are still certain limitations in its application.

[0006] Therefore, there is an urgent need in the market for an active manganese formaldehyde decomposition tablet with highly efficient formaldehyde decomposition and removal performance. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention combines an activated manganese mixed adhesive with a carrier to prepare activated manganese formaldehyde decomposition tablets. The activated manganese mixed adhesive uses a designed and synthesized activated manganese catalyst as the main component, and is combined with binders and dispersants to improve the catalytic activity and stability of traditional activated manganese, thereby enabling the activated manganese formaldehyde decomposition tablets to have highly efficient formaldehyde decomposition and removal performance.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] This invention provides an active manganese formaldehyde decomposition tablet, comprising an active manganese mixed adhesive and a carrier;

[0010] By weight, the active manganese mixed adhesive comprises the following raw materials: 20-30 parts of active manganese catalyst, 4-8 parts of binder, 0.5-3 parts of dispersant, and 50-70 parts of deionized water;

[0011] The carrier is PET nonwoven fabric.

[0012] The PET nonwoven fabric is either PET needle-punched nonwoven fabric or PET spunbond nonwoven fabric.

[0013] In some embodiments of the present invention, the preparation method of the active manganese catalyst includes the following steps:

[0014] (1) Add KMnO4 to the reaction vessel, add deionized water, stir, add concentrated sulfuric acid and methanol in sequence, stir at 90-100℃ for 50-70 min, and obtain a suspension for later use.

[0015] (2) Mix tetramethylammonium chloride and deionized water, stir and add to the suspension in step (1), stir until a precipitate is formed, filter, centrifuge and dry to obtain product 1 for later use.

[0016] (3) Take product 1 from step (2), add deionized water, stir, add Fe(NO3)3 aqueous solution, stir, filter, wash, dry, and obtain product 2 for later use.

[0017] (4) The waste graphite powder is wet ball milled, and the solid is mixed with the product 2 from step (3), ball milled, washed, and dried to obtain the active manganese catalyst.

[0018] In some embodiments of the present invention, the mass ratio of KMnO4 to tetramethylammonium chloride is 1:(3-3.7).

[0019] Preferably, the mass ratio of KMnO4 to tetramethylammonium chloride is 1:3.33.

[0020] In some embodiments of the present invention, in step (3), the mass ratio of product 1 to Fe(NO3)3 in the Fe(NO3)3 aqueous solution is 1:(0.5-0.6).

[0021] Preferably, in step (3), the mass ratio of product 1 to Fe(NO3)3 in the Fe(NO3)3 aqueous solution is 1:0.54.

[0022] In some embodiments of the present invention, in step (4), the mass ratio of product 2 to solid is 1:(0.1-0.3).

[0023] Preferably, in step (4), the mass ratio of product 2 to solid is 1:0.2.

[0024] Activated manganese refers to a catalytic material with manganese dioxide as its main component. Manganese dioxide accelerates the reaction between formaldehyde and oxygen, decomposing formaldehyde into carbon dioxide and water, thereby achieving the purpose of completely removing formaldehyde. However, the catalytic activity and stability of manganese dioxide itself still need to be improved, resulting in its limited ability to decompose formaldehyde at room temperature.

[0025] The applicant first prepared a manganese dioxide suspension using KMnO4 as a raw material, and then modified it by introducing tetramethylammonium chloride. This modifies the suspension by embedding ammonium cations into the interlayer of manganese dioxide, acting as interlayer "pillars" to expand the interlayer spacing and increase the number of active sites, thereby improving the catalytic activity of manganese dioxide. Furthermore, the uniform distribution of ammonium cations within the manganese dioxide layers further enhances the stability of manganese dioxide, increasing its ability to decompose formaldehyde at room temperature. Additionally, the applicant doped Fe into product 1. 3+ The substitution of K in the manganese dioxide interlayer leads to the reconstruction of interlayer active sites, thereby improving oxygen activity. In addition, Fe... 3+ There is a certain interaction force between the ammonium cation and the catalyst, which improves the overall stability of the catalyst. Finally, the applicant uses widely available waste graphite as raw material and performs a simple ball milling process to significantly increase its specific surface area, thereby improving the formaldehyde adsorption capacity of the graphite powder. The product 2 is then combined with the graphite powder to obtain the catalyst, which synergistically improves the overall formaldehyde removal performance and stability of the active manganese catalyst, enabling the obtained active manganese catalyst to have the ability to remove formaldehyde efficiently at room temperature.

[0026] In some embodiments of the present invention, the active manganese mixed adhesive further includes 1-5 parts of quartz micro powder by weight.

[0027] In some embodiments of the present invention, the average particle size of the quartz powder is 3-10 μm.

[0028] The applicant added a certain amount of quartz micropowder of a specific particle size to the activated manganese mixed adhesive. This resulted in good dispersibility and uniformity, which filled the micropores of the activated manganese mixed adhesive, making the material structure more compact. This improved the overall strength and stability of the activated manganese formaldehyde decomposition tablets, thereby extending their service life. Furthermore, the addition of a certain amount of quartz micropowder may also reduce the viscosity of the formaldehyde decomposition tablets to a certain extent, improve their fluidity, and facilitate product extrusion and molding, thus increasing production efficiency.

[0029] In some embodiments of the present invention, the binder is sodium carboxymethyl cellulose or polyvinyl alcohol.

[0030] In some embodiments of the present invention, the dispersant is polyethylene glycol.

[0031] Preferably, the polyethylene glycol is PEG 600 or PEG 2000.

[0032] In another aspect, the present invention provides a method for preparing the activated manganese formaldehyde decomposition tablets described above, comprising the following steps:

[0033] S1. Mix the activated manganese catalyst, quartz powder, binder, dispersant and deionized water, stir to obtain activated manganese mixed adhesive for later use.

[0034] S2. The active manganese mixed adhesive from step S1 is coated onto the carrier to a thickness of 0.2-0.4 mm, extruded, and dried at 100-120℃ for 2-3 hours. After molding, it is cut to obtain active manganese formaldehyde decomposition tablets.

[0035] In step S2, the extrusion pressure is 0.5-2.0 MPa and the time is 30-60 seconds.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) The present invention combines an active manganese mixed adhesive and a carrier to prepare an active manganese formaldehyde decomposition tablet. The active manganese mixed adhesive is mainly composed of a designed and synthesized active manganese catalyst, and is combined with a binder and a dispersant. The active manganese formaldehyde decomposition tablet has the performance of efficiently decomposing and removing formaldehyde and can be widely used in the field of formaldehyde removal technology.

[0038] (2) This invention designs an active manganese catalyst. First, tetramethylammonium chloride is introduced to modify it, and ammonium cations are embedded in the interlayer of manganese dioxide to improve the catalytic activity and stability of manganese dioxide; furthermore, the applicant adds Fe 3+Doping involves Fe replacing interlayer K to reconstruct interlayer active sites, thereby improving oxygen activity. Finally, the applicant uses waste graphite as a carrier material and processes it through ball milling to increase its specific surface area, thereby improving the formaldehyde adsorption capacity of graphite powder. The above product is then combined with wet-ball-milled waste graphite powder to obtain a catalyst, which synergistically improves the overall formaldehyde removal performance and stability of the active manganese catalyst, enabling the obtained active manganese catalyst to have the ability to remove formaldehyde efficiently at room temperature.

[0039] (3) The present invention adds a certain amount of quartz micro powder with a specific particle size, which has good dispersibility and uniformity. It can fill the micropores of the active manganese mixed adhesive, making the structure of the material more compact, improving the overall strength and stability of the active manganese formaldehyde decomposition tablet, and thus extending the service life of the active manganese decomposition tablet. Detailed Implementation

[0040] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0041] In the following examples and comparative examples, except for the active manganese catalyst, all other compound monomers and related reagents used were commercially available. The PET nonwoven fabric was either PET needle-punched nonwoven fabric or PET spunbond nonwoven fabric, both purchased from Jiangxi Haorui Industrial Materials Co., Ltd.; the average particle size of the quartz micropowder was 1 μm, 5 μm, and 10 μm; sodium carboxymethyl cellulose was purchased from Zibo Daoqin New Materials Co., Ltd.; polyvinyl alcohol was purchased from Yuyao Yibai Plastics Co., Ltd.; and polyethylene glycol was PEG 600 or PEG2000.

[0042] Preparation Example 1

[0043] The synthesis method of activated manganese catalyst A includes the following steps:

[0044] (1) Add 12g KMnO4 to the reaction vessel, add 500ml deionized water, stir for 1h, add 7.5g 98wt% concentrated sulfuric acid and 50g methanol in sequence, stir at 95℃ for 60min to obtain a suspension for later use.

[0045] (2) Mix 40g of tetramethylammonium chloride and 500ml of deionized water, stir for 1h, add to the suspension in step (1), stir until a precipitate is formed, filter, centrifuge, and vacuum dry at 60℃ for 12h to obtain product 1 for later use.

[0046] (3) Take 12g of product 1 from step (2), add 200ml of deionized water, stir for 1h, add 13.5ml of 2mol / L Fe(NO3)3 aqueous solution (added in three equal portions), stir for 24h, filter, wash 3 times with deionized water, and vacuum dry at 60℃ for 24h to obtain product 2 for later use.

[0047] (4) 5g of waste graphite powder was wet ball milled at 600r / min for 2h. 2g of solid and 10g of product 2 from step (3) were mixed and ball milled for 30min. The mixture was washed three times with deionized water and vacuum dried at 60℃ for 24h to obtain active manganese catalyst A.

[0048] Preparation Example 2

[0049] The specific implementation method of activated manganese catalyst B is the same as that of activated manganese catalyst A, except that the mass of tetramethylammonium chloride in step (2) is replaced with 34g.

[0050] Preparation Example 3

[0051] The specific implementation method of activated manganese catalyst C is the same as that of activated manganese catalyst A, except that the volume of Fe(NO3)3 aqueous solution in step (3) is replaced with 8 ml.

[0052] Preparation Example 4

[0053] The active manganese catalyst D is implemented in the same way as the active manganese catalyst A, except that the mass of the solid in step (4) is replaced with 0.8g.

[0054] Example 1

[0055] An active manganese formaldehyde decomposition tablet includes an active manganese mixed adhesive and a carrier;

[0056] By weight, the activated manganese formaldehyde decomposition tablets contain the following raw materials: 25 parts activated manganese catalyst A, 3 parts quartz powder, 6 parts sodium carboxymethyl cellulose, 1.5 parts PEG 2000, and 60 parts deionized water.

[0057] The carrier is PET needle-punched nonwoven fabric.

[0058] The average particle size of the quartz powder is 5 μm.

[0059] The preparation method of the activated manganese formaldehyde decomposition tablets in this embodiment includes the following steps:

[0060] S1. Mix activated manganese catalyst A, quartz micro powder, sodium carboxymethyl cellulose, PEG 2000 and deionized water, stir evenly to obtain activated manganese mixed adhesive for later use.

[0061] S2. The active manganese mixed adhesive from step S1 is coated onto PET needle-punched nonwoven fabric to a thickness of 0.3 mm, extruded at 1 MPa for 40 s, dried at 110℃ for 2.5 h, and then cut after molding to obtain active manganese formaldehyde decomposition tablets.

[0062] Example 2

[0063] An active manganese formaldehyde decomposition tablet includes an active manganese mixed adhesive and a carrier;

[0064] By weight, the activated manganese formaldehyde decomposition tablets comprise the following raw materials: 20 parts activated manganese catalyst A, 1 part quartz powder, 4 parts polyvinyl alcohol, 0.5 parts PEG 600, and 50 parts deionized water.

[0065] The carrier is PET spunbond nonwoven fabric.

[0066] The average particle size of the quartz powder is 5 μm.

[0067] The preparation method of the activated manganese formaldehyde decomposition tablets in this embodiment includes the following steps:

[0068] S1. Mix activated manganese catalyst A, quartz powder, polyvinyl alcohol, PEG 600 and deionized water, stir evenly to obtain activated manganese mixed adhesive for later use.

[0069] S2. The active manganese mixed adhesive from step S1 is coated onto PET spunbond nonwoven fabric to a thickness of 0.2 mm, extruded at 0.5 MPa for 60 s, dried at 100 °C for 3 h, and then cut after molding to obtain active manganese formaldehyde decomposition tablets.

[0070] Example 3

[0071] An active manganese formaldehyde decomposition tablet includes an active manganese mixed adhesive and a carrier;

[0072] By weight, the activated manganese formaldehyde decomposition tablets contain the following raw materials: 30 parts activated manganese catalyst A, 5 parts quartz powder, 8 parts polyvinyl alcohol, 3 parts PEG 2000, and 70 parts deionized water.

[0073] The carrier is PET needle-punched nonwoven fabric.

[0074] The average particle size of the quartz powder is 5 μm.

[0075] The preparation method of the activated manganese formaldehyde decomposition tablets in this embodiment includes the following steps:

[0076] S1. Mix activated manganese catalyst A, quartz powder, polyvinyl alcohol, PEG 2000 and deionized water, stir evenly to obtain activated manganese mixed adhesive for later use.

[0077] S2. The active manganese mixed adhesive from step S1 is coated onto PET needle-punched nonwoven fabric to a thickness of 0.4 mm, extruded at 2.0 MPa for 30 s, dried at 120℃ for 2 h, and then cut to obtain active manganese formaldehyde decomposition tablets.

[0078] Example 4

[0079] An active manganese formaldehyde decomposition tablet includes an active manganese mixed adhesive and a carrier;

[0080] By weight, the activated manganese formaldehyde decomposition tablets comprise the following raw materials: 25 parts activated manganese catalyst A, 6 parts sodium carboxymethyl cellulose, 1.5 parts PEG 2000, and 60 parts deionized water.

[0081] The carrier is PET needle-punched nonwoven fabric.

[0082] The average particle size of the quartz powder is 5 μm.

[0083] The preparation method of the activated manganese formaldehyde decomposition tablets in this embodiment includes the following steps:

[0084] S1. Mix activated manganese catalyst A, sodium carboxymethyl cellulose, PEG 2000 and deionized water, stir evenly to obtain activated manganese mixed gel for later use.

[0085] S2. The active manganese mixed adhesive from step S1 is coated onto PET needle-punched nonwoven fabric to a thickness of 0.3 mm, extruded at 1 MPa for 40 s, dried at 110℃ for 2.5 h, and then cut after molding to obtain active manganese formaldehyde decomposition tablets.

[0086] Example 5

[0087] This embodiment provides an active manganese formaldehyde decomposition tablet and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that the average particle size of the quartz micro powder is 1 μm.

[0088] Example 6

[0089] This embodiment provides an active manganese formaldehyde decomposition tablet and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that the average particle size of the quartz micro powder is 15 μm.

[0090] Example 7

[0091] This embodiment provides an active manganese formaldehyde decomposition tablet and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that active manganese catalyst A is replaced by an equal amount of active manganese catalyst B.

[0092] Example 8

[0093] This embodiment provides an active manganese formaldehyde decomposition tablet and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that active manganese catalyst C is used to replace active manganese catalyst A in an equal amount.

[0094] Example 9

[0095] This embodiment provides an active manganese formaldehyde decomposition tablet and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that active manganese catalyst D replaces active manganese catalyst A in an equal amount.

[0096] Example 10

[0097] This embodiment provides an active manganese formaldehyde decomposition tablet and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that manganese dioxide is used to replace the active manganese catalyst A in an equal amount.

[0098] Performance testing

[0099] The formaldehyde removal effect of the activated manganese formaldehyde decomposition tablets in Examples 1-10 above was tested, and the test results are shown in Table 1.

[0100] The activated manganese formaldehyde decomposition tablets from the above embodiments were cut into 10cm × 10cm pieces, and one piece of each was placed in a 10m³ volume container. 3 The initial concentration was 1 mg / m³. 3 In a formaldehyde-sealed room, the formaldehyde removal rate was tested after 24 hours.

[0101] Formaldehyde removal rate (%) = (Initial formaldehyde concentration - Formaldehyde concentration at 24h) / Initial formaldehyde concentration × 100%

[0102] Formaldehyde was tested according to the method specified in GB / T 18204.26-2000.

[0103] Table 1

[0104]

[0105]

[0106] As shown in Table 1, the activated manganese formaldehyde decomposition tablets in Examples 1-3 of this invention exhibit a high overall formaldehyde removal rate, i.e., formaldehyde removal effect. Specifically, Example 4 did not include quartz powder; Examples 5-6 involved altering the particle size of the quartz powder, leading to a decrease in the overall strength and stability of the activated manganese formaldehyde decomposition tablets, thus affecting their formaldehyde removal effect to some extent; Examples 7-9 involved changing the proportions of tetramethylammonium chloride, Fe(NO3)3, and waste graphite powder in the activated manganese catalyst, resulting in a decrease in the catalytic activity or stability of the activated manganese catalyst, thus significantly reducing the formaldehyde removal effect of the activated manganese formaldehyde decomposition tablets; and Example 10 involved replacing activated manganese catalyst A with an equal amount of manganese dioxide, resulting in a significant decrease in the formaldehyde removal effect of the activated manganese formaldehyde decomposition tablets.

[0107] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An active manganese formaldehyde decomposition tablet, characterized in that, Includes active manganese mixed adhesive and carrier; By weight, the active manganese mixed adhesive comprises the following raw materials: 20-30 parts of active manganese catalyst, 4-8 parts of binder, 0.5-3 parts of dispersant, and 50-70 parts of deionized water; The carrier is PET nonwoven fabric.

2. The activated manganese formaldehyde decomposition tablet according to claim 1, characterized in that, The preparation method of the activated manganese catalyst includes the following steps: (1) Add KMnO4 to the reaction vessel, add deionized water, stir, add concentrated sulfuric acid and methanol in sequence, stir at 90-100℃ for 50-70 min, and obtain a suspension for later use. (2) Mix tetramethylammonium chloride and deionized water, stir and add to the suspension in step (1), stir until a precipitate is formed, filter, centrifuge and dry to obtain product 1 for later use. (3) Take product 1 from step (2), add deionized water, stir, add Fe(NO3)3 aqueous solution, stir, filter, wash, dry, and obtain product 2 for later use. (4) The waste graphite powder is wet ball milled, and the solid is mixed with the product 2 from step (3), ball milled, washed, and dried to obtain the active manganese catalyst.

3. The activated manganese formaldehyde decomposition tablet according to claim 2, characterized in that, The mass ratio of KMnO4 to tetramethylammonium chloride is 1:(3-3.7).

4. The activated manganese formaldehyde decomposition tablet according to claim 2, characterized in that, In step (3), the mass ratio of product 1 to Fe(NO3)3 in the Fe(NO3)3 aqueous solution is 1:(0.5-0.6).

5. The activated manganese formaldehyde decomposition tablet according to claim 2, characterized in that, In step (4), the mass ratio of product 2 to solid is 1:(0.1-0.3).

6. The activated manganese formaldehyde decomposition tablet according to claim 1, characterized in that, The active manganese mixed adhesive also includes 1-5 parts of quartz micro powder by weight.

7. The activated manganese formaldehyde decomposition tablet according to claim 6, characterized in that, The average particle size of the quartz micro powder is 3-10 μm.

8. The activated manganese formaldehyde decomposition tablet according to claim 1, characterized in that, The binder is sodium carboxymethyl cellulose or polyvinyl alcohol.

9. The activated manganese formaldehyde decomposition tablet according to claim 1, characterized in that, The dispersant is polyethylene glycol.

10. A method for preparing an active manganese formaldehyde decomposition tablet according to any one of claims 6-9, characterized in that, Includes the following steps: S1. Mix the activated manganese catalyst, quartz powder, binder, dispersant and deionized water, stir to obtain activated manganese mixed adhesive for later use. S2. The active manganese mixed adhesive from step S1 is coated onto the carrier to a thickness of 0.2-0.4 mm, extruded, and dried at 100-120℃ for 2-3 hours. After molding, it is cut to obtain active manganese formaldehyde decomposition tablets.

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