Preparation method and application of metal oxide catalyst with potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide

Abstract

The invention discloses a preparation method of a metal oxide catalyst with a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide, which is characterized in that a manganese ion solution and potassium permanganate are used as raw materials, ultrapure water is used as a solvent, and the metal oxide catalyst is prepared by a hydrothermal synthesis method. According to the metal oxide catalyst with the potassium-manganese-oxygen octahedral molecular sieve structure, the carbon monoxide removal efficiency of the catalyst can be regulated and controlled by adjusting the powder size, and the optimized catalyst can effectively adsorb carbon monoxide and is used for promoting the catalytic oxidation process of carbon monoxide; the size of the catalyst is controlled by using a crusher and a sieve, and the catalyst has excellent catalytic activity and structural stability, can be used for promoting the removal of carbon monoxide, and also has an effective promotion effect on the removal of other toxic and harmful gases, such as nitric oxide, mercury vapor, VOCs (Volatile Organic Compounds) and the like.

Description

Technical Field

[0001] The present application belongs to the technical field of removing carbon monoxide with metal oxide catalysts, and in particular, relates to a preparation method and application of a metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide. Background Art

[0002] Air purification refers to providing overall solutions such as sterilization, dust reduction and haze removal, removal of harmful decoration residues and odors for various indoor environmental problems, improving living and office conditions, and promoting physical and mental health. At present, formaldehyde and carbon monoxide are the main sources of indoor air pollution, which are fatal to the human body; formaldehyde is a colorless and soluble irritant gas. When the indoor content is 0.1 mg / m3, there will be odor and discomfort; 0.5 mg / m3 can irritate the eyes and cause tears; 0.6 mg / m3 can cause throat discomfort or pain; higher concentrations can cause nausea, vomiting, coughing, chest tightness, asthma and even emphysema; 30 mg / m3 can cause immediate death. Long-term exposure to low doses of formaldehyde can also cause chronic respiratory diseases, menstrual disorders in women, pregnancy syndrome, reduced physical fitness of newborns, chromosomal abnormalities, and even nasopharyngeal cancer. Pipeline gas has been basically popularized in many cities, and the rest use liquefied petroleum gas. Although liquefied petroleum gas reduces sulfur and smoke dust in coal combustion, its main components are hydrocarbons such as propane, which can cause poisoning accidents if used improperly. These fuels consume indoor oxygen when burned and emit toxic gases and particles such as carbon monoxide, carbon dioxide, sulfur dioxide, nitrogen oxides, aldehydes, benzopyrene, and fine dust particles of soot, which are irritating to the nervous system, conjunctiva and respiratory mucosa, and are potentially carcinogenic.

[0003] At present, the air purifiers on the market are divided into negative ion type, ozone type, filtration adsorption type, electrostatic integration type and photocatalyst type. Among them, photocatalyst air purifier is a commonly used air purifier. Photocatalyst air purifier is developed with high-efficiency photocatalytic nano titanium dioxide as raw material. The catalyst uses sunlight, ultraviolet light, and fluorescent lamps as light sources to excite electrons (eˉ) in the valence band to transition to the conduction band, generating corresponding holes (h+) in the valence band, generating hydroxyl radicals, superoxide hydroxyl radicals, and superoxide ion radicals with extremely strong oxidizing effects, and oxidizing and decomposing harmful organic matter, pollutants, odors, bacteria, viruses, etc. such as formaldehyde, benzene, toluene, xylene, ammonia, TVOC into harmless CO2 and H2O. However, it needs to work under light conditions, and the purification efficiency of nano titanium dioxide photocatalyst for carbon monoxide is low. Therefore, the purification efficiency of photocatalyst for indoor air is low. Summary of the invention

[0004] The technical problem to be solved by the present application is to overcome the technical defects in the prior art and provide a kind of.

[0005] This application adopts the following technical solutions to solve the above technical problems:

[0006] The present application provides a method for preparing a metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide, characterized in that the catalyst is prepared by a hydrothermal method using a manganese ion solution and potassium permanganate as raw materials and ultrapure water as a solvent.

[0007] Preferably, the method for preparing the metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide specifically comprises the following steps:

[0008] (1) Dissolve potassium permanganate in ultrapure water, add manganese ion solution and stir;

[0009] (2) After stirring, the mixture is allowed to grow naturally and solid-liquid is separated;

[0010] (3) After calcination, crushing is performed.

[0011] Preferably, in step (1), the molar ratio of the manganese ion solution to potassium permanganate is 1:(1.2-2.5), for example 1:1.5.

[0012] In the preparation process, the proportion of potassium permanganate is ensured to be higher than that of manganese solution.

[0013] Preferably, in step (1), the manganese ion solution comprises a manganese nitrate solution.

[0014] The manganese-containing solution may also be replaced by a solution containing the metallic element manganese, or a solution prepared by dissolving manganese ore and nitric acid.

[0015] Preferably, in step (1), the stirring time is 5 to 8 hours.

[0016] Preferably, in step (2), the natural growth time is 10 to 20 hours; the natural growth temperature is 100 to 150°C.

[0017] Among them, the transfer to the oven at 100-150° C. during the natural growth preparation process only provides the catalyst with a suitable growth reaction environment for the catalyst crystals in the solution.

[0018] Preferably, in step (2), drying is further performed after solid-liquid separation, and the drying temperature is 80-120°C.

[0019] Among them, oven drying is adopted, and the drying temperature is also a suitable temperature, in order to ensure that the moisture in the solid is removed and the solid is kept dry before calcination, to ensure the safety of the subsequent calcination process, and not to affect the quality of the catalyst due to moisture.

[0020] Preferably, in step (3), the calcination temperature is 400-600° C., the calcination time is 4-6 hours; and the calcination is carried out in an air atmosphere.

[0021] A metal oxide catalyst with a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide is prepared by the above-mentioned method for preparing a metal oxide catalyst with a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide.

[0022] A metal oxide catalyst with a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide is used as a component in a dry powder fire extinguisher to remove carbon monoxide at a fire scene.

[0023] Preferably, the method can also be applied to the removal of other toxic and harmful gases, including nitric oxide, mercury vapor, and VOCs.

[0024] Among them, the screening during the catalyst preparation process can be ground and screened according to the required size. According to the needs, the catalyst after screening can be a powder, including but not limited to fine powder of 1-100 microns and coarse powder of 100-1000 microns. The catalyst size is fine enough to be made into a dry powder fire extinguisher for removing carbon monoxide at the fire scene. On the basis of conforming to the common sense in the field, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present application.

[0025] The reagents and raw materials used in this application are commercially available.

[0026] The positive effects of this application are:

[0027] The present application discloses a metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure. The powder size can realize the regulation of the removal efficiency of carbon monoxide by the catalyst. The optimized catalyst can effectively adsorb carbon monoxide to promote the catalytic oxidation process of carbon monoxide.

[0028] The present application affects the catalyst microstructure and the catalytic oxidation efficiency of carbon monoxide by changing the catalyst growth environment. In the process of treating the catalyst, the catalyst size is controlled by a crusher and sieving. The catalyst has excellent catalytic activity and structural stability, which is different from the reported catalyst structure to promote the carbon monoxide adsorption catalytic oxidation process. There is no additional introduction of ligands to increase costs and the ligand structure is unstable, resulting in poor cycle stability. The present invention can not only be used to promote the removal of carbon monoxide, but also has an effective promoting effect on the removal of other toxic and harmful gases, such as nitrogen monoxide, mercury vapor, VOCs, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present application can be better understood by referring to the description given below in conjunction with the accompanying drawings. The accompanying drawings, together with the following detailed description, are included in this specification and form a part of this specification, and are used to further illustrate the preferred embodiments of the present application and explain the principles and advantages of the present application.

[0030] in:

[0031] Figure 1 To prepare a flow chart;

[0032] Figure 2 is the crystal structure diagram;

[0033] Figure 3 Figure 2 is a diagram of an activity evaluation device;

[0034] Figure 4 This is a graph of carbon monoxide removal efficiency at different temperatures in N2-O2 atmosphere. DETAILED DESCRIPTION

[0035] The present application is further described below by way of examples, but the present application is not limited to the scope of the examples. The experimental methods without specific conditions in the following examples are selected according to conventional methods and conditions, or according to the product instructions.

[0036] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0037] The raw materials in the following examples are all commercially available.

[0038] Example 1

[0039] The specific preparation process of the metal oxide catalyst with potassium-manganese-oxygen octahedral molecular sieve structure is as follows:

[0040] Take 2.53g of potassium permanganate and dissolve it in a certain amount of ultrapure water, stir it to fully dissolve it, then add manganese nitrate solution to make the molar ratio of manganese nitrate to potassium permanganate be 3:2, transfer it to a stirrer and stir it for more than 5h, transfer it to a heating container after mixing evenly, and let the catalyst grow naturally for about 10h at 120°C, separate the solid and liquid components by filtering, and then wash the solid obtained by the reaction with ultrapure water, and then transfer the washed solid to a drying oven, dry it at a temperature of 100°C until the solid is dry, put it into a muffle furnace after drying, calcine and keep warm for more than 4h in an air atmosphere at 450°C, crush, grind and sieve the calcined solid by a crusher to obtain 3.48g of a granular potassium-manganese-oxygen octahedral molecular sieve structure metal oxide catalyst with uniform size.

[0041] Example 2

[0042] The specific preparation process of the metal oxide catalyst with potassium-manganese-oxygen octahedral molecular sieve structure is as follows:

[0043] Take 2.72g of potassium permanganate and dissolve it in a certain amount of ultrapure water, stir it to fully dissolve, then add manganese nitrate solution to make the molar ratio of manganese nitrate to potassium permanganate close to 4:2, transfer it to a stirrer and stir it for more than 5h, transfer it to a heating container after mixing evenly, and grow the catalyst naturally at 150°C for about 10h, separate the solid and liquid components by filtering, and then wash the solid obtained by the reaction with ultrapure water, and then transfer the washed solid to a drying oven, dry it at a temperature of 80°C until the solid is dry, put it into a muffle furnace after drying, calcine and keep warm for more than 4h in an air atmosphere at 450°C, crush, grind and sieve the calcined solid by a crusher to obtain 3.52g of a metal oxide catalyst with a uniform size of granular potassium-manganese-oxygen octahedral molecular sieve structure.

[0044] Effect Example 1

[0045] Preparation flow chart see Figure 1 , the crystal structure is shown in Figure 2 , the test device diagram of the metal oxide catalyst with potassium-manganese-oxygen octahedral molecular sieve structure is shown in Figure 3 .

[0046] The prepared potassium-manganese-oxygen octahedral molecular sieve structure metal oxide catalyst was subjected to carbon monoxide removal experiments at different temperatures in a N2-O2 atmosphere. The results are shown in Figure 4 .

[0047] Depend on Figure 4 It can be seen from the results that the product prepared in Example 1 of the present application has a carbon monoxide removal efficiency of nearly 100% above 200°C, and the removal effect is excellent.

[0048] Finally, it should be noted that in this application, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0049] Although the present application has been disclosed above through the description of the specific embodiments of the present application, it should be understood that those skilled in the art can design various modifications, improvements or equivalents to the present application within the spirit and scope of the attached scheme. These modifications, improvements or equivalents should also be considered to be included in the scope of protection claimed in the present application.

Claims

1. A method for preparing a metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide, characterized in that: The preparation method is carried out by hydrothermal synthesis method, with manganese ion solution and potassium permanganate as raw materials and ultrapure water as solvent.

2. The method for preparing a metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide according to claim 1, characterized in that: The specific steps include: (1) Dissolve potassium permanganate in ultrapure water, add manganese ion solution and stir; (2) After stirring, the mixture is allowed to grow naturally and solid-liquid is separated; (3) After calcination, crush the mixture.

3. The method for preparing a metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide according to claim 2, characterized in that: In step (1), the molar ratio of the manganese ion solution to potassium permanganate is 1:(1.2-2.5), for example 1:1.

5.

4. The method for preparing a metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide according to claim 2, characterized in that: In step (1), the manganese ion solution includes a manganese nitrate solution.

5. The method for preparing a metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide according to claim 2, characterized in that: In step (1), the stirring time is 5 to 8 hours.

6. The method for preparing the metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide according to claim 2, characterized in that: In step (2), the natural growth time is 10 to 20 hours; the natural growth temperature is 100 to 150°C.

7. The method for preparing a metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide according to claim 2, characterized in that: In step (2), after solid-liquid separation, drying is further included, and the drying temperature is 80-120°C.

8. The method for preparing a metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide according to claim 2, characterized in that: In step (3), the calcination temperature is 400-600° C., and the calcination time is 4-6 hours; and the calcination is carried out in an air atmosphere.

9. A metal oxide catalyst having a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide, which is prepared by the preparation method according to any one of claims 1 to 8.

10. A metal oxide catalyst with a potassium-manganese-oxygen octahedral molecular sieve structure for removing carbon monoxide, used as a component in a dry powder fire extinguisher to remove carbon monoxide at a fire scene; Preferably, the method can also be applied to the removal of other toxic and harmful gases, including nitric oxide, mercury vapor, and VOCs.

Images