Preparation method and application of MnFeOx / silicon dioxide fiber catalyst
By preparing MnFeOx/silica fiber catalyst, the problems of powder catalyst loss and high cost of precious metal catalysts are solved, and the effect of efficient oxidation of formaldehyde under room temperature conditions is achieved, and the operation cost and secondary pollution risk are reduced.
Patent Information
- Application Number
- CN202510024417.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-07
- Publication Date
- 2025-03-25
AI Technical Summary
During use, existing powder catalysts are prone to drift with the airflow, causing catalyst loss and contamination. The cost of precious metal catalysts is high, which limits practical applications.
Using the preparation method of MnFeOx/silica fiber catalyst, a catalyst in fiber form was prepared through hydrothermal reaction and calcining steps, avoiding the loss of powder catalyst and reducing the cost through the design of precious metals.
The catalytic decomposition effect of formaldehyde reaches more than 98% under room temperature, and has excellent indoor formaldehyde treatment effect, reducing operating costs and avoiding secondary pollution of the catalyst.
Smart Images
Figure CN119680565A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of fiber catalyst preparation, and in particular to a MnFeOx / silicon dioxide fiber catalyst and a preparation method and application thereof. Background Art
[0002] Indoor pollutants have become one of the five most important environmental factors affecting public health. Among them, formaldehyde is an indoor pollutant that has a significant adverse impact on the environment and humans. Its pollution to the indoor environment is long-term, latent and difficult to avoid. Indoor formaldehyde mainly comes from the release of gaseous formaldehyde in indoor decoration materials. How to eliminate formaldehyde in room temperature in a green and efficient way has become a research hotspot.
[0003] Based on whether the chemical structure of formaldehyde pollutants is destroyed during the treatment process, it can be divided into two categories: the first category is physical method, which selects suitable adsorbents to adsorb formaldehyde under certain temperature and pressure conditions; the second category is chemical method, that is, in the external environment (such as light, electricity, heat, etc.) or under the action of catalysts or plants, formaldehyde is converted into CO2 and H2O by chemical reactions or biodegradation, thereby achieving complete degradation of pollutants. The main research methods currently include physical adsorption technology, plant degradation technology, plasma technology, photocatalytic oxidation technology and thermal catalytic oxidation technology.
[0004] Thermal catalytic oxidation technology is a purification technology that directly decomposes formaldehyde into carbon dioxide and water by activating oxygen in the air with a catalyst. It has the characteristics of high efficiency and no secondary pollution. The efficiency of formaldehyde catalytic oxidation depends on the performance of the catalyst. At present, the catalyst used in this method is a scarce precious metal-based catalyst. Although it has strong low-temperature oxidation activity and stability, its high price limits its application in real life. At the same time, most traditional catalysts are powders, which are easy to drift with the airflow during use, causing problems such as catalyst loss and pollution. Based on this, a MnFeOx / silica fiber catalyst is developed, which can not only catalyze and oxidize formaldehyde efficiently at room temperature, but also reduce the operating cost without the use of precious metals. In addition, the fiber catalyst also prevents the catalyst from entering the indoor environment and causing secondary pollution to the environment. Summary of the invention
[0005] In view of this, the present invention provides a MnFeOx / silicon dioxide fiber catalyst and a preparation method and application thereof, so as to solve the problems that the existing powder catalyst is easily dispersed with the air flow, causing the loss and pollution of the catalyst.
[0006] In order to achieve the above object, the present invention adopts the following technical solution:
[0007] A method for preparing a MnFeOx / silicon dioxide fiber catalyst comprises the following steps:
[0008] (1) tetraethyl silicate and a solvent are mixed, heated and evaporated to obtain a first spinning solution, and the spinning solution is electrostatically spun to obtain silica fibers;
[0009] (2) mixing manganese salt, iron salt and water for a period of time, then placing the silica fiber membrane into the mixed solution, transferring the entire solution to a hydrothermal reactor, and placing it in an oven at a certain temperature for a period of time to perform a hydrothermal reaction;
[0010] (3) After the hydrothermal reactor in step (3) is cooled to room temperature, the metal-loaded silica fiber precursor is taken out and calcined in air to obtain a MnFeOx / silica fiber catalyst.
[0011] Preferably, the solvent in step (1) is a mixture of 0.2% hydrochloric acid solution and ethanol, the ratio of 0.2% hydrochloric acid solution to ethanol is 1:2-3; the ratio of tetraethyl silicate to solvent is 1:0.4-0.9; and the voltage of electrospinning is 18-25 kV.
[0012] Preferably, the manganese salt in step (2) comprises one or more of manganese carbonate, manganese acetate tetrahydrate, manganese acetate, manganese (II) oxalate dihydrate, manganese acetate dihydrate, manganese (III) phosphate hydrate, manganese (III) acetylacetonate, manganese (II) nitrate tetrahydrate and potassium permanganate; and the iron salt comprises one or more of ferric phosphate, ferric citrate, ferric oxalate, ferric acetate, ferrous carbonate, iron (III) sulfate hydrate, ferric nitrate, iron (III) nitrate nonahydrate and ferrous acetate.
[0013] Preferably, in step (2), the molar ratio of manganese salt to iron salt is 1:1-1.5; the hydrothermal reaction temperature is 80-200° C.; and the hydrothermal reaction time is 18-24 h.
[0014] Preferably, the calcination temperature in step (3) is 400-800° C. and the calcination time is 4-12 h.
[0015] The present invention also provides a MnFeOx / silicon dioxide fiber catalyst prepared by the preparation method of the MnFeOx / silicon dioxide fiber catalyst.
[0016] The present invention also provides the MnFeOx / silicon dioxide fiber catalyst for removing low-concentration formaldehyde at room temperature.
[0017] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:
[0018] The MnFeOx / silicon dioxide fiber catalyst obtained by the present invention can efficiently oxidize formaldehyde at room temperature, and the catalytic decomposition effect of formaldehyde reaches more than 98%, which greatly improves the application range of the MnFeOx / silicon dioxide fiber catalyst and has an excellent indoor formaldehyde treatment effect.
[0019] The preparation process of the MnFeOx / silicon dioxide fiber catalyst of the present invention is simple, the reaction conditions are mild, no large-scale equipment is required, the cost is saved, and a new idea is provided for the preparation of the catalyst required for the treatment of indoor formaldehyde. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.
[0021] Figure 1 This is a physical picture of the metal-loaded silica fiber precursor obtained in Example 1 of the present invention;
[0022] Figure 2 This is a physical picture of the MnFeOx / silica fiber catalyst obtained in Example 1 of the present invention. DETAILED DESCRIPTION
[0023] A method for preparing a MnFeOx / silicon dioxide fiber catalyst comprises the following steps:
[0024] (1) tetraethyl silicate and a solvent are mixed, heated and evaporated to obtain a first spinning solution, and the spinning solution is electrostatically spun to obtain silica fibers;
[0025] (2) mixing manganese salt, iron salt and water for a period of time, then placing the silica fiber membrane into the mixed solution, transferring the entire solution to a hydrothermal reactor, and placing it in an oven at a certain temperature for a period of time to perform a hydrothermal reaction;
[0026] (3) After the hydrothermal reactor in step (3) is cooled to room temperature, the metal-loaded silica fiber precursor is taken out and calcined in air to obtain a MnFeOx / silica fiber catalyst.
[0027] In the present invention, the solvent in step (1) is a mixture of 0.2% hydrochloric acid solution and ethanol, the ratio of 0.2% hydrochloric acid solution to ethanol is 1:2-3, more preferably 1:2.1-2.8; the ratio of tetraethyl silicate to solvent is 1:0.4-0.9, more preferably 1:0.45-0.85; the voltage of electrospinning is 18-25kV, more preferably 19-24kV.
[0028] In the present invention, the manganese salt in step (2) comprises one or more of manganese carbonate, manganese acetate tetrahydrate, manganese acetate, manganese (II) oxalate dihydrate, manganese acetate dihydrate, manganese (III) phosphate hydrate, manganese (III) acetylacetonate, manganese (II) nitrate tetrahydrate and potassium permanganate; the iron salt comprises one or more of ferric phosphate, ferric citrate, ferric oxalate, ferric acetate, ferrous carbonate, iron (III) sulfate hydrate, ferric nitrate, iron (III) nitrate nonahydrate and ferrous acetate.
[0029] In the present invention, the molar ratio of manganese salt to iron salt in step (2) is 1:1-1.5, more preferably 1:1.05-1.45; the hydrothermal reaction temperature is 80-200°C, more preferably 90-190°C; the hydrothermal reaction time is 18-24h, more preferably 19-22h.
[0030] In the present invention, the calcination temperature in step (3) is 400-800° C., more preferably 450-750° C.; the calcination time is 4-12 h, more preferably 5-11 h.
[0031] The present invention also provides a MnFeOx / silicon dioxide fiber catalyst prepared by the preparation method of the MnFeOx / silicon dioxide fiber catalyst.
[0032] The present invention also provides the MnFeOx / silicon dioxide fiber catalyst for removing low-concentration formaldehyde at room temperature.
[0033] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.
[0034] Example 1
[0035] 6.4 g of tetraethyl silicate, 2.2 g of anhydrous ethanol and 1.0 g of 0.2% hydrochloric acid solution were weighed and mixed, and stirred at 80° C. at a rotation speed of 450 r / min for 30 min to obtain a spinning solution.
[0036] The parameters of the electrospinning for preparing the silica fiber are as follows: the voltage of the electrospinning is 19 kV, the receiving device is coated with aluminum foil on the receiving roller, the distance between the spinning needle and the receiving roller is 20 cm, the rotation speed of the receiving roller is 120 r / min, the translation speed of the electrospinning needle is 250 mm / min, the translation stroke of the electrospinning is 450 mm, the spinning temperature is 25 ° C, and the relative humidity is 35%.
[0037] Weigh 1.79g of manganese nitrate and 2.66g of ferric nitrate, add them to 80mL of distilled water, and stir for 30min. Then put the silica fiber membrane into the mixed solution, transfer the entire solution to a hydrothermal reactor, and the hydrothermal reaction temperature is 100°C for 20h to obtain a metal-loaded silica fiber precursor.
[0038] After the hydrothermal reactor was cooled to room temperature, the metal-loaded silica fiber precursor was taken out and calcined in air at a temperature of 600° C. for 9 h to obtain a MnFeOx / silica fiber catalyst.
[0039] The MnFeOx / silica fiber catalyst obtained in this example was used to catalytically oxidize indoor air containing formaldehyde, and the decomposition rate of formaldehyde was above 98%.
[0040] Example 2
[0041] 6.0 g of tetraethyl silicate, 2.6 g of anhydrous ethanol and 1 g of 0.2% hydrochloric acid solution were weighed and mixed, and stirred at 80° C. at a rotation speed of 450 r / min for 30 min to obtain a spinning solution.
[0042] The parameters of the electrospinning for preparing the silica fiber are as follows: the voltage of the electrospinning is 20 kV, the receiving device is coated with aluminum foil on the receiving roller, the distance between the spinning needle and the receiving roller is 20 cm, the rotation speed of the receiving roller is 120 r / min, the translation speed of the electrospinning needle is 250 mm / min, the translation stroke of the electrospinning is 450 mm, the spinning temperature is 25 ° C, and the relative humidity is 35%.
[0043] Weigh 2.69g of manganese nitrate and 7.88g of iron (III) nitrate nonahydrate, add them to 80mL of distilled water, and stir for 30min. Then put the silica fiber membrane into the mixed solution, transfer the entire solution to a hydrothermal reactor, and the hydrothermal reaction temperature is 140°C for 19h to obtain a metal-loaded silica fiber precursor.
[0044] After the hydrothermal reactor was cooled to room temperature, the metal-loaded silica fiber precursor was taken out and calcined in air at a temperature of 750° C. for 10 h to obtain a MnFeOx / silica fiber catalyst.
[0045] The MnFeOx / silica fiber catalyst obtained in this example was used to catalytically oxidize indoor air containing formaldehyde, and the decomposition rate of formaldehyde was above 98%.
[0046] Example 3
[0047] 7.4 g of tetraethyl silicate, 2.35 g of anhydrous ethanol and 1 g of 0.2% hydrochloric acid solution were weighed and mixed, and stirred at 80° C. at a rotation speed of 450 r / min for 30 min to obtain a spinning solution.
[0048] The parameters of the electrospinning for preparing the silica fiber are as follows: the voltage of the electrospinning is 20 kV, the receiving device is coated with aluminum foil on the receiving roller, the distance between the spinning needle and the receiving roller is 18 cm, the rotation speed of the receiving roller is 120 r / min, the translation speed of the electrospinning needle is 250 mm / min, the translation stroke of the electrospinning is 450 mm, the spinning temperature is 25 ° C, and the relative humidity is 35%.
[0049] Weigh 2.45g of manganese acetate tetrahydrate and 2.18g of ferric acetate, add them to 80mL of distilled water, and stir for 30min. Then put the silica fiber membrane into the mixed solution, transfer the entire solution to a hydrothermal reactor, the hydrothermal reaction temperature is 190°C, the hydrothermal reaction time is 16h, and a metal-loaded silica fiber precursor is obtained.
[0050] After the hydrothermal reactor was cooled to room temperature, the metal-loaded silica fiber precursor was taken out and calcined in air at a temperature of 700° C. for 8 h to obtain a MnFeOx / silica fiber catalyst.
[0051] The MnFeOx / silica fiber catalyst obtained in this example was used to catalytically oxidize indoor air containing formaldehyde, and the decomposition rate of formaldehyde was above 98%.
[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for preparing a MnFeOx / silicon dioxide fiber catalyst, characterized in that: The following steps are involved: (1) tetraethyl silicate and a solvent are mixed, heated and evaporated to obtain a first spinning solution, and the spinning solution is electrostatically spun to obtain silica fibers; (2) Mixing manganese salt, iron salt and water for a period of time, and then adding the mixed solution of silica fiber membrane to the hydrothermal reaction kettle, and placing it in an oven at a certain temperature for a period of time; (3) After the hydrothermal reactor in step (3) is cooled to room temperature, the metal-loaded silica fiber precursor is taken out and calcined in air to obtain a MnFeOx / silica fiber catalyst.
2. The method for preparing a MnFeOx / silicon dioxide fiber catalyst according to claim 1, characterized in that: The solvent in step (1) is a mixture of 0.2% hydrochloric acid solution and ethanol, the ratio of 0.2% hydrochloric acid solution to ethanol is 1:2-3; the ratio of tetraethyl silicate to solvent is 1:0.4-0.9; and the voltage of electrospinning is 18-25 kV.
3. The method for preparing a MnFeOx / silicon dioxide fiber catalyst according to claim 1, characterized in that: In step (2), the manganese salt comprises one or more of manganese carbonate, manganese acetate tetrahydrate, manganese acetate, manganese (II) oxalate dihydrate, manganese acetate dihydrate, manganese (III) phosphate hydrate, manganese (III) acetylacetonate, manganese (II) nitrate tetrahydrate and potassium permanganate; and the iron salt comprises one or more of ferric phosphate, ferric citrate, ferric oxalate, ferric acetate, ferrous carbonate, iron (III) sulfate hydrate, ferric nitrate, iron (III) nitrate nonahydrate and ferrous acetate.
4. The method for preparing a MnFeOx / silicon dioxide fiber catalyst according to claim 1, characterized in that: In step (2), the molar ratio of manganese salt to iron salt is 1:1-1.5; the hydrothermal reaction temperature is 80-200° C.; and the hydrothermal reaction time is 18-24 hours.
5. The method for preparing a MnFeOx / silicon dioxide fiber catalyst according to claim 1, characterized in that: The calcination temperature in step (3) is 400-800° C. and the calcination time is 4-12 hours.
6. The MnFeOx / silica fiber catalyst prepared by the method for preparing the MnFeOx / silica fiber catalyst according to any one of claims 1 to 5.
7. Use of the MnFeOx / silicon dioxide fiber catalyst according to claim 6 in formaldehyde oxidation, characterized in that: The catalyst removes low-concentration formaldehyde at room temperature with a removal rate of 98%.