Iron-manganese-based filter element material for catalytic purification of VOCs (volatile organic compounds) at room temperature and preparation method

Abstract

The invention relates to the technical field of air filter elements, in particular to an iron-manganese-based filter element material for catalyzing and purifying VOCs (volatile organic compounds) at room temperature and a preparation method of the iron-manganese-based filter element material. The iron-manganese-based filter element material for catalyzing and purifying the VOCs at the room temperature is prepared from the following raw materials in parts by mass: 20 to 30 parts of ferrous sulfate, 30 to 40 parts of manganese sulfate, 0.1 to 1 part of ceric ammonium nitrate, 1 to 2 parts of hexadecyl trimethyl ammonium bromide, 1 to 3 parts of urea steam, 5 to 15 parts of attapulgite clay, 1 to 5 parts of aerogel aid and 1 to 5 parts of sodium alginate. The preparation method is simple, the adsorption capacity and the adsorption capacity of indoor volatile organic pollutants such as formaldehyde are greatly improved, the formaldehyde removal efficiency can be improved, the service life of the material can be prolonged, and the material is suitable for large-scale popularization and application.

Description

Technical Field

[0001] The present invention relates to the technical field of air filter elements, and in particular to an iron-manganese-based filter element material for catalytically purifying VOCs at room temperature and a preparation method thereof. Background Art

[0002] The control of indoor volatile organic compounds (VOCs) is one of the core challenges in the current air purification field. Harmful gases such as formaldehyde and benzene are highly volatile, release slowly over long periods of time, and are highly toxic. Traditional adsorption materials (such as activated carbon) rely on physical adsorption, which has the drawbacks of low adsorption capacity and easy saturation failure.

[0003] Activated carbon materials desorb after reaching saturation, leading to the risk of secondary pollution. Frequent filter replacement significantly increases operating costs. In recent years, photocatalytic materials, such as titanium dioxide, have been shown to degrade pollutants, but their dependence on ultraviolet light for activation limits their effectiveness in low-light indoor environments.

[0004] Transition metal oxide catalysts are currently attracting much attention due to their room-temperature catalytic activity. However, single metal oxides suffer from issues such as insufficient catalytically active sites and low lattice oxygen mobility. For example, pure manganese oxides are susceptible to activity decay during cyclic reactions due to insufficient lattice oxygen replenishment. While iron oxides possess excellent redox properties, they have a low specific surface area and a single valence state, which limits the formation of surface oxygen vacancies.

[0005] Therefore, developing a filter element material that has high adsorption capacity, long-term catalytic activity and is suitable for room temperature environments has become a key direction to break through the current technical bottleneck. Summary of the Invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an iron-manganese-based filter element material and a preparation method for catalytic purification of VOCs at room temperature.

[0007] Disclosed is an iron-manganese-based filter element material for catalytic purification of VOCs at room temperature. The raw materials thereof comprise, by mass, 20-30 parts of ferrous sulfate, 30-40 parts of manganese sulfate, 0.1-1 part of ceric ammonium nitrate, 1-2 parts of hexadecyltrimethylammonium bromide, 1-3 parts of urea vapor, 5-15 parts of attapulgite clay, 1-5 parts of an aerogel additive, and 1-5 parts of sodium alginate.

[0008] Preferably, the mesh size of the attapulgite clay is 300-400 mesh.

[0009] Preferably, the aerogel additive is prepared by the following steps: adding graphene oxide to water and ultrasonically treating for 10-30 minutes, adding ascorbic acid and sodium thiosulfate, continuing ultrasonic treatment for 10-30 minutes, placing it above liquid nitrogen for directionally freezing, washing, freeze-drying, adding it to a γ-aminopropyltriethoxysilane ethanol solution, stirring at 50-60°C for 1-2 hours, washing, and freeze-drying.

[0010] Preferably, the mass ratio of graphene oxide, ascorbic acid, sodium thiosulfate, and γ-aminopropyltriethoxysilane is 1-5:0.5-2:0.05-0.2:0.1-1.2.

[0011] Preferably, the ultrasound frequency is 30-50 kHz.

[0012] Preferably, the mass fraction of the γ-aminopropyltriethoxysilane ethanol solution is 1-2%.

[0013] The method for preparing the above-mentioned filter element material for iron-manganese-based catalytic purification of VOCs at room temperature comprises the following steps:

[0014] S1. Add ferrous sulfate and manganese sulfate to water and stir evenly, add cerium ammonium nitrate and hexadecyltrimethylammonium bromide, stir at 80-90°C for 10-30min, adjust the pH value of the solution to 9-10, heat to 180-200°C for hydrothermal reaction for 10-20h, and after completion of the reaction, pass into an inert atmosphere for protection cooling, centrifuge, wash, and dry to obtain a prefabricated material;

[0015] S2. The prefabricated material is placed in a calcining furnace, heated to 500-600°C in a nitrogen-ammonia mixed atmosphere, and calcined for 1-2 hours by introducing urea vapor. The prefabricated material is cooled to room temperature, crushed, and attapulgite clay and aerogel additive are added and mixed evenly. Sodium alginate is added and stirred evenly. The prefabricated material is pressed into shape, dried, and calcined at 200-400°C for 1-2 hours.

[0016] Preferably, in S1, a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution with a concentration of 1-2 mol / L is used to adjust the pH value of the solution to 9-10.

[0017] Preferably, in S1, the inert atmosphere is a nitrogen atmosphere or an argon atmosphere.

[0018] Preferably, in S2, the volume fraction of ammonia in the nitrogen-ammonia mixed atmosphere is 5-10%.

[0019] Beneficial effects:

[0020] The present invention constructs mesoporous channels by using CTAB template and introduces Ce by using cerium ammonium nitrate. 3+ / Ce 4+For redox couple, the spatial confinement effect generated by the mesoporous channels promotes the enrichment of formaldehyde molecules in the channels, and Ce activates the lattice oxygen mobility of adjacent Fe-Mn sites through dynamic valence changes, achieving synergistic enhancement of adsorption-catalysis.

[0021] In the process of preparing the aerogel additive, the present invention controls the growth direction of ice crystals to form through holes, which are then compounded with attapulgite clay and prefabricated materials to form a multi-level structure. Not only does the specific surface area increase greatly, but a silane coupling agent is used to form a strong interface bond with attapulgite clay and metal oxides, significantly improving the electron conduction efficiency. The combined effect can provide a rapid diffusion channel for formaldehyde molecules, and can catalytically purify indoor volatile organic pollutants at room temperature, with excellent catalytic activity.

[0022] At the same time, the present invention adopts ammonia roasting combined with urea vapor nitridation to form a nitrogen-doped structure on the surface of the metal oxide, and the aerogel additive forms a chemically bonded interface with the metal oxide to construct a rapid electron transmission channel, greatly extending the formaldehyde penetration adsorption time.

[0023] The invention not only has a simple preparation method, but also greatly improves the adsorption ability and adsorption capacity for indoor volatile organic pollutants such as formaldehyde, can improve the efficiency of removing formaldehyde and the service life of the material, and is suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a comparison chart of the adsorption capacity of formaldehyde at different concentrations by the filter element materials and activated carbon obtained in Example 5 and Comparative Examples 1-3.

[0025] Figure 2 This is a comparison chart of the formaldehyde penetration adsorption time of the filter element materials obtained in Example 5 and Comparative Examples 1-3 and activated carbon.

[0026] Figure 3 This is a curve diagram of the formaldehyde removal rate of the filter element materials and activated carbon obtained in Example 5 and Comparative Examples 1-3 within 1 hour. DETAILED DESCRIPTION

[0027] The present invention will be further explained below with reference to specific embodiments.

[0028] Example 1

[0029] The invention discloses an iron-manganese-based filter element material for catalytically purifying VOCs at room temperature. The raw materials thereof include: 20 g of ferrous sulfate, 30 g of manganese sulfate, 0.1 g of ceric ammonium nitrate, 1 g of hexadecyltrimethylammonium bromide, 1 g of urea vapor, 5 g of 300-mesh attapulgite clay, 1 g of an aerogel additive, and 1 g of sodium alginate.

[0030] The aerogel additive was prepared by the following steps: 1 g of graphene oxide was added to 30 g of deionized water and ultrasonically treated for 10 min at an ultrasonic frequency of 30 kHz, 1 g of ascorbic acid and 0.1 g of sodium thiosulfate were added, and ultrasonic treatment was continued for 10 min. The mixture was placed above liquid nitrogen for direction freezing, washed, and freeze-dried. The mixture was added to 30 g of a 1% mass fraction of γ-aminopropyltriethoxysilane ethanol solution, stirred at 50°C for 1 h, washed with ethanol, and freeze-dried.

[0031] The method for preparing the above-mentioned filter element material for iron-manganese-based catalytic purification of VOCs at room temperature comprises the following steps:

[0032] S1, ferrous sulfate and manganese sulfate were added to 100g deionized water and stirred evenly, ceric ammonium nitrate and hexadecyltrimethylammonium bromide were added, and the mixture was stirred at 80°C for 10min at a stirring speed of 100r / min, and a 1mol / L potassium hydroxide aqueous solution was added thereto to adjust the pH value of the solution to 9-10, and the mixture was transferred to a hydrothermal reactor, heated to 180°C and kept warm for 10h, and after the hydrothermal reaction, an argon atmosphere was introduced for protection cooling, centrifuged, washed with ethanol and deionized water in sequence, and dried to obtain a prefabricated material;

[0033] S2. The prefabricated material was fed into a calcining furnace, heated to 500°C at a rate of 1°C / min in a nitrogen-ammonia mixed atmosphere (ammonia volume fraction is 5%), urea vapor was introduced into the prefabricated material, and the prefabricated material was calcined for 1 hour. The prefabricated material was cooled to room temperature and crushed. The attapulgite clay and aerogel additive were added and mixed evenly. Then, sodium alginate was added and stirred evenly. The prefabricated material was pressed into shape, dried at 120°C for 5 hours, and calcined at 200°C for 1 hour.

[0034] Example 2

[0035] The invention discloses an iron-manganese-based filter element material for catalytically purifying VOCs at room temperature. The raw materials thereof include: 30 g of ferrous sulfate, 40 g of manganese sulfate, 1 g of ceric ammonium nitrate, 2 g of hexadecyltrimethylammonium bromide, 3 g of urea vapor, 15 g of 400-mesh attapulgite clay, 5 g of an aerogel additive, and 5 g of sodium alginate.

[0036] The aerogel additive was prepared by the following steps: 5 g of graphene oxide was added to 60 g of deionized water and ultrasonically treated for 30 min at an ultrasonic frequency of 50 kHz, 2 g of ascorbic acid and 0.2 g of sodium thiosulfate were added, and ultrasonic treatment was continued for 30 min. The mixture was placed above liquid nitrogen for direction freezing, washed, and freeze-dried. The mixture was added to 60 g of a 2% mass fraction γ-aminopropyltriethoxysilane ethanol solution, stirred at 60°C for 2 h, washed with ethanol, and freeze-dried.

[0037] The method for preparing the above-mentioned filter element material for iron-manganese-based catalytic purification of VOCs at room temperature comprises the following steps:

[0038] S1, ferrous sulfate and manganese sulfate were added to 200g deionized water and stirred evenly, ceric ammonium nitrate and hexadecyltrimethylammonium bromide were added, and the mixture was stirred at 90°C for 30min at a stirring speed of 200r / min, and a 2mol / L sodium hydroxide aqueous solution was added thereto to adjust the pH value of the solution to 9-10, and the mixture was transferred to a hydrothermal reactor, heated to 200°C and kept warm for 20h, and after the hydrothermal reaction, a nitrogen atmosphere was introduced for protection cooling, centrifuged, washed with ethanol and deionized water in sequence, and dried to obtain a prefabricated material;

[0039] S2. The prefabricated material is fed into a calcining furnace, heated to 600°C at a rate of 5°C / min in a nitrogen-ammonia mixed atmosphere (ammonia volume fraction is 10%), urea vapor is introduced into it, and the material is calcined for 2 hours. The material is cooled to room temperature and crushed. Attapulgite clay and aerogel additive are added and mixed evenly. Then, sodium alginate is added and stirred evenly. The material is pressed into shape, dried at 130°C for 10 hours, and calcined at 400°C for 2 hours.

[0040] Example 3

[0041] Disclosed is an iron-manganese-based filter element material for catalytic purification of VOCs at room temperature. The raw materials thereof include: 22 g of ferrous sulfate, 37 g of manganese sulfate, 0.3 g of ceric ammonium nitrate, 1.7 g of hexadecyltrimethylammonium bromide, 1.5 g of urea vapor, 12 g of 350-mesh attapulgite clay, 2 g of an aerogel additive, and 4 g of sodium alginate.

[0042] The aerogel additive was prepared by the following steps: 2 g of graphene oxide was added to 50 g of deionized water and ultrasonically treated for 15 minutes at an ultrasonic frequency of 45 kHz, 1.3 g of ascorbic acid and 0.18 g of sodium thiosulfate were added, and ultrasonic treatment was continued for 15 minutes. The mixture was placed above liquid nitrogen for direction freezing, washed, and freeze-dried. The mixture was added to 50 g of a 1.5% mass fraction of γ-aminopropyltriethoxysilane ethanol solution, stirred at 52°C for 100 minutes, washed with ethanol, and freeze-dried.

[0043] The method for preparing the above-mentioned filter element material for iron-manganese-based catalytic purification of VOCs at room temperature comprises the following steps:

[0044] S1, ferrous sulfate and manganese sulfate were added to 120g deionized water and stirred evenly, ceric ammonium nitrate and hexadecyltrimethylammonium bromide were added, and the mixture was stirred at 88°C for 15min at a stirring speed of 150r / min, and a 1.7mol / L sodium hydroxide aqueous solution was added thereto to adjust the pH value of the solution to 9-10, and the mixture was transferred to a hydrothermal reactor, heated to 185°C and kept warm for 18h, and after the hydrothermal reaction, a nitrogen atmosphere was introduced for protection cooling, centrifugation, and sequentially washed with ethanol and deionized water, and dried to obtain a prefabricated material;

[0045] S2. The prefabricated material was fed into a calcining furnace, heated to 520°C at a rate of 4°C / min in a nitrogen-ammonia mixed atmosphere (ammonia volume fraction is 7%), urea vapor was introduced into the prefabricated material, and the prefabricated material was calcined for 100 min. The prefabricated material was cooled to room temperature and crushed. Attapulgite clay and aerogel additive were added and mixed evenly. Then, sodium alginate was added and stirred evenly. The prefabricated material was pressed into shape, dried at 122°C for 9 h, and calcined at 250°C for 100 min.

[0046] Example 4

[0047] Disclosed is an iron-manganese-based filter element material for catalytic purification of VOCs at room temperature. The raw materials thereof include: 28 g of ferrous sulfate, 33 g of manganese sulfate, 0.7 g of ceric ammonium nitrate, 1.3 g of hexadecyltrimethylammonium bromide, 2.5 g of urea vapor, 8 g of 350-mesh attapulgite clay, 4 g of an aerogel additive, and 2 g of sodium alginate.

[0048] The aerogel additive was prepared by the following steps: 4 g of graphene oxide was added to 40 g of deionized water and ultrasonically treated for 25 min at an ultrasonic frequency of 35 kHz, 1.7 g of ascorbic acid and 0.12 g of sodium thiosulfate were added, and ultrasonic treatment was continued for 25 min. The mixture was placed above liquid nitrogen for direction freezing, washed, and freeze-dried. The mixture was then added to 40 g of a 1.5% mass fraction of γ-aminopropyltriethoxysilane ethanol solution, stirred at 58°C for 80 min, washed with ethanol, and freeze-dried.

[0049] The method for preparing the above-mentioned filter element material for iron-manganese-based catalytic purification of VOCs at room temperature comprises the following steps:

[0050] S1, ferrous sulfate and manganese sulfate were added to 180g deionized water and stirred evenly, ceric ammonium nitrate and hexadecyltrimethylammonium bromide were added, and the mixture was stirred at 82°C for 25min at a stirring speed of 150r / min, and a 1.3mol / L sodium hydroxide aqueous solution was added thereto to adjust the pH value of the solution to 9-10, and the mixture was transferred to a hydrothermal reactor, heated to 195°C and kept warm for 12h, and after the hydrothermal reaction, a nitrogen atmosphere was introduced for protection cooling, centrifugation, and washed with ethanol and deionized water in sequence, and dried to obtain a prefabricated material;

[0051] S2. The prefabricated material was fed into a calcining furnace, heated to 580°C at a rate of 2°C / min in a nitrogen-ammonia mixed atmosphere (ammonia volume fraction is 9%), urea vapor was introduced into the prefabricated material, and the prefabricated material was calcined for 80 min. The prefabricated material was cooled to room temperature and crushed. Attapulgite clay and aerogel additive were added and mixed evenly. Then, sodium alginate was added and stirred evenly. The prefabricated material was pressed into shape, dried at 128°C for 7 h, and calcined at 350°C for 80 min.

[0052] Example 5

[0053] The invention discloses an iron-manganese-based filter element material for catalytically purifying VOCs at room temperature. The raw materials thereof include: 25 g of ferrous sulfate, 35 g of manganese sulfate, 0.5 g of ceric ammonium nitrate, 1.5 g of hexadecyltrimethylammonium bromide, 2 g of urea vapor, 10 g of 350-mesh attapulgite clay, 3 g of an aerogel additive, and 3 g of sodium alginate.

[0054] The aerogel additive was prepared by the following steps: 3 g of graphene oxide was added to 45 g of deionized water and ultrasonically treated for 20 min at an ultrasonic frequency of 39 kHz, 1.5 g of ascorbic acid and 0.15 g of sodium thiosulfate were added, and ultrasonic treatment was continued for 20 min. The mixture was placed above liquid nitrogen for direction freezing, washed, and freeze-dried. The mixture was then added to 45 g of a 1.5% mass fraction of γ-aminopropyltriethoxysilane ethanol solution, stirred at 55°C for 90 min, washed with ethanol, and freeze-dried.

[0055] The method for preparing the above-mentioned filter element material for iron-manganese-based catalytic purification of VOCs at room temperature comprises the following steps:

[0056] S1, ferrous sulfate and manganese sulfate were added to 150g deionized water and stirred evenly, ceric ammonium nitrate and hexadecyltrimethylammonium bromide were added, and the mixture was stirred at 85°C for 20min at a stirring speed of 150r / min, and a 1.5mol / L sodium hydroxide aqueous solution was added thereto to adjust the pH value of the solution to 9-10, and the mixture was transferred to a hydrothermal reactor, heated to 190°C and kept warm for 15h, and after the hydrothermal reaction, a nitrogen atmosphere was introduced for protection cooling, centrifugation, and washed with ethanol and deionized water in sequence, and dried to obtain a prefabricated material;

[0057] S2. The prefabricated material was fed into a calcining furnace, heated to 550°C at a rate of 3°C / min in a nitrogen-ammonia mixed atmosphere (ammonia volume fraction is 8%), urea vapor was introduced into the prefabricated material, and the prefabricated material was calcined for 90 min. The prefabricated material was cooled to room temperature and crushed. Attapulgite clay and aerogel additive were added and mixed evenly. Then, sodium alginate was added and stirred evenly. The prefabricated material was pressed into shape, dried at 125°C for 8 h, and calcined at 300°C for 90 min.

[0058] Comparative Example 1

[0059] Disclosed is an iron-manganese-based filter element material for catalytic purification of VOCs at room temperature. The raw materials thereof include: 25 g of ferrous sulfate, 35 g of manganese sulfate, 0.5 g of ceric ammonium nitrate, 2 g of urea vapor, 11.5 g of 350-mesh attapulgite clay, 3 g of an aerogel additive, and 3 g of sodium alginate.

[0060] The aerogel additive was prepared by the following steps: 3 g of graphene oxide was added to 45 g of deionized water and ultrasonically treated for 20 min at an ultrasonic frequency of 39 kHz, 1.5 g of ascorbic acid and 0.15 g of sodium thiosulfate were added, and ultrasonic treatment was continued for 20 min. The mixture was placed above liquid nitrogen for direction freezing, washed, and freeze-dried. The mixture was then added to 45 g of a 1.5% mass fraction of γ-aminopropyltriethoxysilane ethanol solution, stirred at 55°C for 90 min, washed with ethanol, and freeze-dried.

[0061] The method for preparing the above-mentioned filter element material for iron-manganese-based catalytic purification of VOCs at room temperature comprises the following steps:

[0062] S1, ferrous sulfate and manganese sulfate were added to 150g deionized water and stirred evenly, ceric ammonium nitrate was added, and stirred at a temperature of 85 ° C for 20min at a stirring speed of 150r / min, a 1.5mol / L sodium hydroxide aqueous solution was added thereto to adjust the pH value of the solution to 9-10, and the solution was transferred to a hydrothermal reactor, heated to 190 ° C and kept warm for 15h, and after the hydrothermal reaction, a nitrogen atmosphere was introduced for protection cooling, centrifugation, and washed with ethanol and deionized water in sequence, and dried to obtain a prefabricated material;

[0063] S2. The prefabricated material was fed into a calcining furnace, heated to 550°C at a rate of 3°C / min in a nitrogen-ammonia mixed atmosphere (ammonia volume fraction is 8%), urea vapor was introduced into the prefabricated material, and the prefabricated material was calcined for 90 min. The prefabricated material was cooled to room temperature and crushed. Attapulgite clay and aerogel additive were added and mixed evenly. Then, sodium alginate was added and stirred evenly. The prefabricated material was pressed into shape, dried at 125°C for 8 h, and calcined at 300°C for 90 min.

[0064] Comparative Example 2

[0065] The invention discloses an iron-manganese-based filter element material for catalytically purifying VOCs at room temperature. The raw materials thereof include: 25 g of ferrous sulfate, 35 g of manganese sulfate, 0.5 g of ceric ammonium nitrate, 1.5 g of hexadecyltrimethylammonium bromide, 2 g of urea vapor, 10 g of 350-mesh attapulgite clay, 3 g of an aerogel additive, and 3 g of sodium alginate.

[0066] The aerogel additive was prepared by the following steps: 3 g of graphene oxide was added to 45 g of deionized water and ultrasonically treated for 20 min at an ultrasonic frequency of 39 kHz, 1.5 g of ascorbic acid and 0.15 g of sodium thiosulfate were added, and ultrasonic treatment was continued for 20 min. The mixture was placed above liquid nitrogen for direction freezing, washed, and freeze-dried. The mixture was then added to 45 g of a 1.5% mass fraction of γ-aminopropyltriethoxysilane ethanol solution, stirred at 55°C for 90 min, washed with ethanol, and freeze-dried.

[0067] The method for preparing the above-mentioned filter element material for iron-manganese-based catalytic purification of VOCs at room temperature comprises the following steps:

[0068] S1, ferrous sulfate and manganese sulfate were added to 150g deionized water and stirred evenly, ceric ammonium nitrate and hexadecyltrimethylammonium bromide were added, and the mixture was stirred at 85°C for 20min at a stirring speed of 150r / min, and a 1.5mol / L sodium hydroxide aqueous solution was added thereto to adjust the pH value of the solution to 9-10, and the mixture was transferred to a hydrothermal reactor, heated to 190°C and kept warm for 15h, and after the hydrothermal reaction, a nitrogen atmosphere was introduced for protection cooling, centrifugation, and washed with ethanol and deionized water in sequence, and dried to obtain a prefabricated material;

[0069] S2. The prefabricated material is fed into a calcining furnace, heated to 550°C at a rate of 3°C / min under a nitrogen atmosphere, urea vapor is introduced therein, and the material is calcined for 90 minutes. The material is cooled to room temperature and crushed. Attapulgite clay and aerogel additive are added and mixed evenly. Sodium alginate is then added and stirred evenly. The material is pressed into shape, dried at 125°C for 8 hours, and calcined at 300°C for 90 minutes.

[0070] Comparative Example 3

[0071] The invention discloses an iron-manganese-based filter element material for catalytically purifying VOCs at room temperature. The raw materials thereof include: 25 g of ferrous sulfate, 35 g of manganese sulfate, 0.5 g of ceric ammonium nitrate, 1.5 g of hexadecyltrimethylammonium bromide, 2 g of urea vapor, 10 g of 350-mesh attapulgite clay, 3 g of an aerogel additive, and 3 g of sodium alginate.

[0072] The aerogel additive was prepared by the following steps: 3 g of graphene oxide was added to 45 g of deionized water and ultrasonically treated for 20 min at an ultrasonic frequency of 39 kHz, 1.5 g of ascorbic acid and 0.15 g of sodium thiosulfate were added, and ultrasonic treatment was continued for 20 min. The mixture was conventionally frozen, washed, and freeze-dried. The mixture was added to 45 g of a 1.5% mass fraction of γ-aminopropyltriethoxysilane ethanol solution, stirred at 55°C for 90 min, washed with ethanol, and freeze-dried.

[0073] The method for preparing the above-mentioned filter element material for iron-manganese-based catalytic purification of VOCs at room temperature comprises the following steps:

[0074] S1, ferrous sulfate and manganese sulfate were added to 150g deionized water and stirred evenly, ceric ammonium nitrate and hexadecyltrimethylammonium bromide were added, and the mixture was stirred at 85°C for 20min at a stirring speed of 150r / min, and a 1.5mol / L sodium hydroxide aqueous solution was added thereto to adjust the pH value of the solution to 9-10, and the mixture was transferred to a hydrothermal reactor, heated to 190°C and kept warm for 15h, and after the hydrothermal reaction, a nitrogen atmosphere was introduced for protection cooling, centrifugation, and washed with ethanol and deionized water in sequence, and dried to obtain a prefabricated material;

[0075] S2. The prefabricated material was fed into a calcining furnace, heated to 550°C at a rate of 3°C / min in a nitrogen-ammonia mixed atmosphere (ammonia volume fraction is 8%), urea vapor was introduced into the prefabricated material, and the prefabricated material was calcined for 90 min. The prefabricated material was cooled to room temperature and crushed. Attapulgite clay and aerogel additive were added and mixed evenly. Then, sodium alginate was added and stirred evenly. The prefabricated material was pressed into shape, dried at 125°C for 8 h, and calcined at 300°C for 90 min.

[0076] Formaldehyde is taken as a representative substance of indoor volatile organic pollutants (VOCs).

[0077] The filter materials obtained in Example 5 and Comparative Examples 1-3 were loaded into the ultra-low concentration formaldehyde adsorption detection system, respectively, at a formaldehyde concentration of 0.1 mg / m 3 , 0.2mg / m 3 , 0.3mg / m 3 The formaldehyde adsorption was measured under the conditions of , and the results were given by proton transfer reaction mass spectrometry. Activated carbon was used as the control group.

[0078] like Figure 1 As shown, the filter element material obtained in Example 5 has the best adsorption effect on formaldehyde, which is significantly better than the filter element materials and activated carbon obtained in Comparative Examples 1-3 (P < 0.05).

[0079] The filter element material and activated carbon obtained in Example 5 and Comparative Examples 1-3 were dried to constant weight, crushed to 40-60 mesh, and 0.385 g of each was weighed and filled into a glass reaction tube with an inner diameter of 5.3 mm. The bed heights were 28 mm, 45 mm, 31 mm, and 33 mm, respectively. The reaction tube was connected to a stable formaldehyde adsorption detection system for sample testing: the inlet flow rate was 0.5 L / min, the formaldehyde concentration in the inlet air was 2.8 ppm, air was used as the carrier gas, and the time required for the formaldehyde concentration at the bed outlet to reach 1.0 ppm was defined as the penetration adsorption time.

[0080] like Figure 2 As shown, the formaldehyde penetration adsorption time of the filter element material obtained in Example 5 is significantly longer than that of the filter element materials and activated carbon obtained in Comparative Examples 1-3 (P < 0.05), so its service life is longer.

[0081] 1 kg of the filter element material and activated carbon obtained in Example 5 and Comparative Examples 1-3 were respectively loaded into a filling filter screen and sealed, and then loaded into an air purifier. The 1-hour formaldehyde removal rate test was performed according to the clean air volume test method for gaseous pollutants in GB / T 18801-2015 "Air Purifier".

[0082] like Figure 3 As shown, the formaldehyde removal rate of the filter element material obtained in Example 5 is the highest, which is better than the filter element materials and activated carbon obtained in Comparative Examples 1-3 (P < 0.05).

[0083] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An iron-manganese-based filter material for room temperature catalytic purification of VOCs, characterized in that: The raw materials include, by mass, 20-30 parts of ferrous sulfate, 30-40 parts of manganese sulfate, 0.1-1 part of ceric ammonium nitrate, 1-2 parts of hexadecyltrimethylammonium bromide, 1-3 parts of urea vapor, 5-15 parts of attapulgite clay, 1-5 parts of aerogel additive, and 1-5 parts of sodium alginate.

2. The filter element material for catalytic purification of VOCs by iron-manganese-based room temperature according to claim 1, characterized in that: The mesh size of attapulgite clay is 300-400 mesh.

3. The filter element material for catalytic purification of VOCs by iron-manganese-based room temperature according to claim 1, characterized in that: The aerogel additive is prepared by the following steps: adding graphene oxide to water and ultrasonically treating it for 10-30 minutes, adding ascorbic acid and sodium thiosulfate, continuing ultrasonic treatment for 10-30 minutes, placing it above liquid nitrogen for directionally freezing, washing, freeze-drying, adding it to a γ-aminopropyltriethoxysilane ethanol solution, stirring at 50-60° C. for 1-2 hours, washing, and freeze-drying.

4. The filter element material for catalytic purification of VOCs by iron-manganese-based room temperature according to claim 3, characterized in that: The mass ratio of graphene oxide, ascorbic acid, sodium thiosulfate and gamma-aminopropyltriethoxysilane is 1-5:0.5-2:0.05-0.2:0.1-1.

2.

5. The filter element material for catalytic purification of VOCs by iron-manganese-based room temperature according to claim 3, characterized in that: The ultrasonic frequency is 30-50kHz.

6. The filter element material for catalytic purification of VOCs by iron-manganese-based room temperature according to claim 3, characterized in that: The mass fraction of the γ-aminopropyltriethoxysilane ethanol solution is 1-2%.

7. A method for preparing an iron-manganese-based filter material for room-temperature catalytic purification of VOCs according to any one of claims 1 to 6, characterized in that: The steps include: S1. Add ferrous sulfate and manganese sulfate to water and stir evenly, add cerium ammonium nitrate and hexadecyltrimethylammonium bromide, stir at 80-90°C for 10-30min, adjust the pH value of the solution to 9-10, heat to 180-200°C for hydrothermal reaction for 10-20h, and after completion of the reaction, pass into an inert atmosphere for protection cooling, centrifuge, wash, and dry to obtain a prefabricated material; S2. The prefabricated material is placed in a calcining furnace, heated to 500-600°C in a nitrogen-ammonia mixed atmosphere, and calcined for 1-2 hours by introducing urea vapor. The prefabricated material is cooled to room temperature, crushed, and attapulgite clay and aerogel additive are added and mixed evenly. Sodium alginate is added and stirred evenly. The prefabricated material is pressed into shape, dried, and calcined at 200-400°C for 1-2 hours.

8. The method for preparing a filter element material for catalytic purification of VOCs by iron-manganese-based filtration at room temperature according to claim 7, characterized in that: In S1, a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution with a concentration of 1-2 mol / L is used to adjust the pH value of the solution to 9-10.

9. The method for preparing a filter element material for catalytic purification of VOCs by iron-manganese-based filtration at room temperature according to claim 7, characterized in that: In S1, the inert atmosphere is a nitrogen atmosphere or an argon atmosphere.

10. The method for preparing a filter element material for catalytic purification of VOCs by iron-manganese-based filtration at room temperature according to claim 7, characterized in that: In S2, the volume fraction of ammonia in the nitrogen-ammonia mixed atmosphere is 5-10%.

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