Preparation and application of a non-metallic single atom-loaded manganese oxide nanomaterial

Abstract

The present invention discloses a method for preparing a non-metallic single-atom-supported manganese oxide nanomaterial and its application. The prepared catalyst carrier comprises manganese oxide with exposed crystal faces, and the active component comprises non-metallic atoms present as single-atom sites. The manganese oxide may be manganese tetraoxide, manganese trioxide, or manganese dioxide; the non-metallic single atoms include, but are not limited to, nitrogen, sulfur, phosphorus, and fluorine atoms. This non-metallic single-atom-supported manganese oxide nanocatalyst can efficiently catalyze ozone and oxidize benzene under low-temperature conditions, playing a significant role in treating or repairing the atmospheric environment.

Description

Technical Field

[0001] The present invention relates to a method for preparing a non-metallic single-atom-loaded manganese oxide nanomaterial, and also relates to the application of the non-metallic single-atom-loaded manganese oxide nanomaterial as an important component of a catalyst in the treatment of volatile organic compounds from industrial sources, belonging to the technical field of industrial catalysts. Background Art

[0002] Energy and the environment are paramount issues concerning the sustainable development of human society. Currently, 80% of global energy demand comes from fossil fuels, which will ultimately lead to their depletion, and their use also causes severe environmental pollution. Pollutants such as volatile organic compounds (VOCs) emitted from industry and daily life not only directly threaten human health but also generate smog, severely polluting the atmosphere and causing secondary pollution.

[0003] With the rapid development of the global economy and society, the emission of greenhouse gases (such as CO2) has also increased dramatically, leading to rapid global warming. How to effectively reduce greenhouse gas emissions is one of the most pressing issues facing the world.

[0004] Human health and the ecological environment are inextricably linked. In recent years, emissions of volatile organic compounds (VOCs) from industrial sources have increased dramatically. VOCs have been shown to be important precursors to the formation of secondary organic aerosols and photochemical smog.

[0005] At present, the physical and chemical treatment methods for VOCs mainly include adsorption, incineration and catalytic oxidation, but these methods still have defects such as incomplete treatment and high energy consumption.

[0006] In contrast, catalytic ozone oxidation is an emerging treatment method that combines high efficiency, low energy consumption, and low cost, making it fully capable of low-temperature purification of VOCs. Catalysts play a key role in the catalytic ozone oxidation reaction, accelerating the decomposition of ozone while also increasing its utilization rate. Transition metal oxides, precious metals, and carbon materials have been extensively studied in the catalytic ozone removal of VOCs. Manganese oxide, due to its rich valence states, diverse structures, and high stability, holds great promise for future applications.

[0007] Manganese oxide nanomaterials, as catalyst raw materials, are a highly sought-after catalytic oxidation method with significant practical application value and mature technology. To further improve the efficiency of catalysts prepared from manganese oxide nanomaterials, existing technologies primarily utilize precious metal loading and ion doping to enhance the performance of manganese oxide nanomaterials in catalyzing ozone oxidation of VOCs by increasing oxygen vacancy concentrations.

[0008] However, oxygen vacancies, which serve as activation sites for ozone, can become deactivated during the catalytic reaction due to the filling of oxygen atoms. Existing techniques generally involve surface chemical modification to reduce the formation energy of oxygen vacancies, thereby promoting the generation of more oxygen vacancies in manganese oxide catalysts. However, since only a single oxygen vacancy serves as an active site in the catalytic reaction, the treated manganese oxide catalyst still suffers from catalyst deactivation. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a method for preparing and applying a non-metallic single atom-loaded manganese oxide nanomaterial. The manganese oxide nanomaterial is used as a catalyst raw material to fundamentally solve the above-mentioned deactivation problem.

[0010] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0011] According to a first aspect of an embodiment of the present invention, a method for preparing a non-metallic single atom-supported manganese oxide nanomaterial is provided, comprising the following steps:

[0012] The manganese oxide nanorods with the (101) crystal plane exposed are denoted as nanorods D. 0.3 g of the manganese oxide nanorods D and 1 to 2 g of sodium hypophosphite are placed in two porcelain boats of a tubular furnace respectively; the sodium hypophosphite is placed in the upwind direction and the nanorods D are placed in the downwind direction; in a high-purity nitrogen atmosphere, the heating rate is set to 2°C / min, and after the temperature reaches 250 to 350°C, constant temperature heat treatment is performed for 2 hours; after the reaction is completed, a non-metallic single-atom phosphorus-loaded manganese oxide nanomaterial is obtained.

[0013] Specifically, the method for preparing the manganese oxide nanorods with the (101) crystal surface exposed comprises the following steps:

[0014] Step 1:

[0015] Dissolve 0.237 g of pure potassium permanganate in 60 mL of ultrapure water and stir continuously until completely dissolved to obtain solution A.

[0016] Step 2:

[0017] 1.5 mL of ethylene glycol was slowly added dropwise to solution A prepared in step 1 and stirred evenly for 1 hour to obtain solution B;

[0018] Step 3:

[0019] Transfer the solution B prepared in step 2 to a polytetrafluoroethylene-lined reactor and heat at 120°C for 6 h;

[0020] Step 4:

[0021] After the reaction in step 3 is completed, the precipitated material is washed and then slowly dried to obtain precursor C;

[0022] Step 5:

[0023] 0.35 g of precursor C was placed in a porcelain boat in a tube furnace and heat treated at 450°C for 4 h in a high-purity argon atmosphere with a heating rate of 5°C / min. After the reaction, manganese oxide nanorods with the (101) surface exposed were obtained.

[0024] Preferably, in the non-metallic single-atom phosphorus-loaded manganese oxide nanomaterial, the phosphorus atom exists above the middle of the manganese atom and the oxygen atom on the (101) crystal plane, coordinates with the manganese atom and the oxygen atom at the same time, and the phosphorus atom is evenly distributed on the surface of the manganese oxide.

[0025] Specifically, in the non-metallic single-atom phosphorus-loaded manganese manganese oxide nanomaterial, the loading amount of phosphorus is 4 wt %.

[0026] According to a second aspect of an embodiment of the present invention, a method for applying a non-metallic single atom-supported manganese oxide nanomaterial is provided, comprising the following steps:

[0027] The catalyst is a non-metallic single-atom phosphorus-loaded manganese tetraoxide nanomaterial. 0.1 g of the catalyst is mixed evenly with 1 g of quartz sand and placed in a quartz tube of a fixed-bed reactor. The quartz tube is then placed vertically, with ozone and the gas to be catalyzed flowing from top to bottom.

[0028] Specifically, the flow rate of the substance to be oxidized is 25 mL / min, and the flow rate of ozone is 25 mL / min; under the reaction conditions of 60 minutes at 50°C, the substance to be oxidized can be completely oxidized by ozone activated by non-metallic single-atom phosphorus-loaded manganese tetraoxide nanomaterials.

[0029] Manganese oxide alone has poor catalyst activity and requires further modification and improvement. To further enhance the performance of manganese oxide in catalyzing the oxidation of VOCs, strategies such as oxygen vacancy construction and element doping can be used to construct active sites. The present invention utilizes single-atom loading to enhance catalyst activity, resulting in ultra-high atom utilization, a dramatic increase in surface free energy, quantum size effects, and an unsaturated coordination environment. This unique structure enables it to exhibit superior catalytic performance compared to conventional metal catalysts or metal oxide catalysts.

[0030] Non-metallic single atoms have the advantages of low cost, simple synthesis methods, and high loading capacity. To date, research on non-metallic single atoms is limited, and no technical reports have yet reported non-metallic single-atom-loaded manganese oxide catalysts and their application in the catalytic ozone oxidation of VOCs.

[0031] Single-atom catalysts have the advantages of maximum atomic utilization, significant catalytic activity, and superior reaction selectivity, and are being used to solve various energy and environmental problems. Current research on single-atom materials mainly focuses on precious metal single-atom catalysts such as Au, Pt, Pd, and Ru. However, metal single-atom catalysts are potentially unstable due to metal-support interactions. When the interaction between the support and the single-atom site is too weak, the isolated active sites are prone to metal aggregation or loss. When the interaction between the support and the single-atom site is too strong, although the stability of the single-atom site is improved, the excessively strong interaction will lead to reduced catalytic activity.

[0032] The synthesis of metal single-atom supported catalysts is mainly carried out through co-precipitation, atomic layer deposition, mass separation-soft landing, reverse Ostward ripening, photochemical reduction and other methods. The synthesis process of the above methods is cumbersome, the cost is high, and the loading amount is low (generally less than 0.5wt%), which is not conducive to practical application and difficult to promote. Non-metallic single-atom catalysts can form stable single-atom sites by coordinating with the metal on the carrier. The introduction of non-metallic single atoms can change the electronegativity of adjacent metal sites and thus improve their catalytic performance. The introduction of single-atom P with low electronegativity can reduce the adsorption energy of reaction intermediates on the metal center, thereby accelerating the reaction kinetics.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] This invention provides, for the first time, a method for preparing manganese oxide nanomaterials loaded with non-metallic single atoms using manganese oxide as a substrate. The key is the ability to create dual active sites, effectively addressing the deactivation issue of single oxygen vacancies. The construction of single-atom catalysts is an effective way to introduce dual sites.

[0035] 2. The non-metallic single-atom-loaded manganese oxide nanomaterial prepared using the technical means provided by the present invention has a relatively simple preparation process, low synthesis energy consumption in existing reactions, and a loading capacity of 4% for non-metallic single-atom P. Using the commonly used impregnation technique, the loading capacity of single-atom Ag on the manganese oxide nanomaterial is 0.26-0.5%. This shows that the technical solution provided by the present invention can significantly increase the loading capacity, achieving both quantitative and qualitative improvements.

[0036] 3. The non-metallic single-atom-loaded manganese oxide nanomaterials prepared using the technical means provided by this invention have high catalytic activity and can efficiently catalyze the oxidation of atmospheric pollutants such as benzene by ozone, playing a significant role in the treatment or restoration of the atmospheric environment. This breakthrough in technical barriers has enabled the loading of non-metallic single atoms onto metal oxides for the first time, while also developing a completely new modification direction to enhance the catalytic effect of manganese oxide as a catalyst, further broadening the application scenarios of its catalytic effect. This also provides an efficient and stable catalyst for achieving low-temperature treatment of atmospheric pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the X-ray powder diffraction pattern (XRD pattern) of Mn3O4 in Example 1.

[0038] Figure 2 This is a transmission electron microscope (TEM) photograph of Mn3O4 in Example 1, showing the overall morphology of the nanorods.

[0039] Figure 3 for Figure 2 A partial enlarged view of .

[0040] Figure 4 This is the HR-TEM image of Mn3O4 in Example 1, showing the lattice fringes of the nanorods.

[0041] Figure 5 This is the X-ray powder diffraction pattern (XRD pattern) of PSAC / Mn3O4 in Example 1.

[0042] Figure 6 This is a transmission electron microscopy (TEM) photograph of PSAC / Mn3O4 nanorods in Example 1, and a diagram of the overall morphology of the nanorods.

[0043] Figure 7 for Figure 6 A partial enlarged view of .

[0044] Figure 8 HR-TEM image of PSAC / Mn3O4, showing the lattice fringes of nanorods.

[0045] Figure 9 This is the single-atom P distribution diagram of PSAC / Mn3O4 nanorods in Example 1 under the scanning transmission electron microscope (STEM) ABF mode.

[0046] Figure 10 This is the scanning transmission electron microscopy (STEM) mapping of P, Mn, O and other elements of PSAC / Mn3O4 nanorods in Example 1.

[0047] Figure 11Schematic diagram of a fixed bed reactor.

[0048] Figure 12 Schematic diagram of the spatial relationship between manganese, oxygen, and phosphorus atoms in the PSAC / Mn3O4 crystal structure in Example 1. DETAILED DESCRIPTION

[0049] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments provided by the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0052] First, the preparation steps of manganese dioxide nanorods are introduced.

[0053] Step 1:

[0054] Dissolve 0.237 g of pure potassium permanganate in 60 mL of ultrapure water and stir continuously until completely dissolved to obtain solution A.

[0055] Step 2:

[0056] 1.5 mL of ethylene glycol was slowly added dropwise to solution A prepared in step 1 and stirred evenly for 1 hour to obtain solution B;

[0057] Step 3:

[0058] Transfer the solution B prepared in step 2 to a polytetrafluoroethylene-lined reactor and heat at 120°C for 6 h;

[0059] Step 4:

[0060] After the reaction in step 3 is completed, the obtained precipitate is washed with ultrapure water and anhydrous ethanol for more than three times, and then the prepared product is slowly dried in an oven at 80°C, and then slowly dried in an oven at 80°C for 4 hours to obtain precursor C;

[0061] Step 5:

[0062] 0.35 g of precursor C was placed in a porcelain boat in a tubular furnace and heat treated at 450 °C for 4 h in an atmosphere of high-purity argon. The heating rate was set to 5 °C / min. After the reaction, manganese oxide nanorods with (101) surface exposed were obtained, which were recorded as nanorods D.

[0063] Example 1: Preparation of non-metallic single-atom phosphorus-supported manganese tetraoxide nanomaterials

[0064] Manganese oxide nanorods with exposed (101) surface were first prepared by the above method, which were denoted as nanorods D and will not be described in detail here.

[0065] 0.3 g of the prepared manganese oxide nanorods D and 2 g of sodium hypophosphite were placed in two porcelain boats of a tube furnace respectively; the sodium hypophosphite was placed in the upwind direction and the nanorods D were placed in the downwind direction.

[0066] In a high-purity nitrogen atmosphere, the heating rate was set to 2°C / min, and after the temperature reached 300°C, constant temperature heat treatment was performed for 2 hours.

[0067] After the reaction is completed, the non-metallic single-atom phosphorus-loaded manganese tetraoxide nanomaterial is obtained and is recorded as PSAC / Mn3O4.

[0068] Figure 1 Shown is the X-ray powder diffraction pattern (XRD pattern) of Mn3O4 in Example 1. Figure 5 This is the X-ray powder diffraction pattern (XRD pattern) of PSAC / Mn3O4 in Example 1. Comparing the two patterns, it is clear that no new substances are generated after PSAC is loaded on the surface of Mn3O4.

[0069] Figures 2 to 4 This is a transmission electron microscope photograph of Mn3O4 in Example 1. Measurement shows that the interplanar spacing is 0.35 nm, corresponding to the (101) crystal plane. Therefore, the Mn3O4 prepared in Example 1 is a crystal type with the (101) crystal plane exposed.

[0070] Figures 6 and 7is a transmission electron micrograph (TEM) of PSAC / Mn3O4 nanorods in Example 1, and Figures 2 to 4 In contrast, after P loading, Mn3O4 still maintains a good nanorod structure without any morphological changes. At the same time, the interplanar spacing is still 0.35nm, and no lattice distortion occurs. This indicates that the crystal form of Mn3O4 is not changed after PSAC loading.

[0071] Figure 9 Scanning transmission electron microscopy (STEM) image of PSAC / Mn3O4 nanorods; single atom P distribution map under ABF mode. Figure 10 The scanning transmission electron microscopy (STEM) mapping of P, Mn, O and other elements of PSAC / Mn3O4 nanorods shows that the phosphorus atom exists in a single atomic state. The phosphorus atom exists above the manganese atom and oxygen atom in the (101) crystal plane, and it is coordinated with both the manganese atom and the oxygen atom (e.g. Figure 12 As shown in FIG, the phosphorus atoms are uniform on the surface of the manganese oxide, and the phosphorus loading is 4 wt%.

[0072] Next, the catalytic performance of the non-metallic single-atom phosphorus-supported manganese tetraoxide nanomaterial PSAC / Mn3O4 prepared in Example 1 was tested:

[0073] like Figure 11 In the fixed-bed reactor shown, the oxygen source is a 20% oxygen / nitrogen mixture. Oxygen flows through a mass flow meter (MFC) into an ozone generator to generate ozone, with online measurement monitoring of the ozone concentration before the reaction. The benzene source is a 10 ppm benzene / nitrogen mixture. Both gases flow through the MFC at controlled rates before entering the fixed-bed catalyst reactor. Ozone and benzene in the reaction products are monitored online.

[0074] Specifically, the fixed-bed catalyst was designed as follows: 0.1g of PSAC / Mn3O4 was mixed evenly with 1g of quartz sand and then loaded into a 50cm long, 8mm diameter quartz tube. The tube was then placed vertically with ozone and benzene flowing from top to bottom. The reaction temperature range was set between 25 and 100°C, and the residence time at each temperature was controlled to be 30 to 60 minutes.

[0075] Take 0.1 g of manganese oxide nanorods (nanorod D) with the (101) surface exposed, select a benzene concentration of 10 ppm, a benzene flow rate of 25 mL / min, and an ozone concentration of 50 ppm, with a flow rate of 25 mL / min.

[0076] 0.1 g of PSAC / Mn3O4 prepared in this example was mixed evenly with 1 g of quartz sand, and then placed into a quartz tube with a length of 50 cm and a diameter of 8 mm.

[0077] Place the quartz tube in Figure 11 For the fixed bed reactor shown in the figure, the benzene concentration was 10 ppm, the benzene flow rate was 25 mL / min, and the ozone flow rate was 25 mL / min. The test results are shown in Table 1 below:

[0078] Table 1 Conversion rate of benzene oxidized by ozone of Mn3O4 and PSAC / Mn3O4 at different temperatures

[0079]

[0080] According to the conversion rate-temperature of benzene oxidation catalyzed by PSAC / Mn3O4 nanomaterials in the above table, when the reaction temperature is 50°C, the conversion rate of benzene can reach 100%.

[0081] According to the conversion rate-temperature relationship of benzene oxidation catalyzed by ozone with the (101) surface exposed manganese oxide nanorods, when the reaction temperature is 50°C, the conversion rate of benzene can only reach 65.8%.

[0082] Under the same conditions, the activity test was conducted by replacing 10 ppm of benzene with 10 ppm of formaldehyde and 10 ppm of propane, respectively. The average flow rate of formaldehyde and propane was 25 mL / min, and the ozone flow rate was 25 mL / min. P-loaded Mn₃O₄ was able to activate ozone and completely oxidize formaldehyde and propane at both 25°C and 50°C for 60 minutes.

[0083] This indicates that loading of non-metallic single-atom phosphorus significantly enhances the ability of manganese tetraoxide to catalyze the oxidation of VOCs by ozone. This is primarily due to the fact that the non-metallic single-atom phosphorus coordinates with both manganese and oxygen atoms on the catalyst surface to form a stable structure. Furthermore, the non-metallic single-atom phosphorus and the adjacent manganese atoms form dual active sites for ozone adsorption and activation, thus avoiding the problem of single-site oxygen vacancies being filled and deactivated by oxygen atoms.

[0084] Example 2: Preparation of non-metallic single-atom phosphorus-supported manganese tetraoxide nanomaterials

[0085] The aforementioned method first prepares manganese oxide nanorods with the (101) surface exposed, which are denoted as nanorods D and will not be described in detail here.

[0086] 0.3 g of the prepared manganese oxide nanorods D and 1 g of sodium hypophosphite were placed in two porcelain boats of a tube furnace respectively; the sodium hypophosphite was placed in the upwind direction and the nanorods D were placed in the downwind direction.

[0087] In a high-purity nitrogen atmosphere, the heating rate was set to 2°C / min, and after the temperature reached 300°C, constant temperature heat treatment was performed for 2 hours.

[0088] After the reaction is completed, the non-metallic single-atom phosphorus-loaded manganese tetraoxide nanomaterial is obtained and is recorded as PSAC / Mn3O4.

[0089] Next, the catalytic performance of the non-metallic single-atom phosphorus-supported manganese tetraoxide nanomaterial PSAC / Mn3O4 prepared in Example 2 was tested:

[0090] 0.1 g of PSAC / Mn3O4 prepared in this example was mixed evenly with 1 g of quartz sand, and then placed into a quartz tube with a length of 50 cm and a diameter of 8 mm.

[0091] The quartz tube was placed in a fixed-bed reactor, with a benzene concentration of 10 ppm, a benzene flow rate of 25 mL / min, and an ozone flow rate of 25 mL / min. The test results are shown in the table below.

[0092] Table 2

[0093]

[0094] Example 3: Preparation of non-metallic single-atom phosphorus-supported manganese tetraoxide nanomaterials

[0095] The aforementioned method first prepares manganese oxide nanorods with the (101) surface exposed, which are denoted as nanorods D and will not be described in detail here.

[0096] 0.3 g of the prepared manganese oxide nanorods D and 2 g of sodium hypophosphite were placed in two porcelain boats of a tube furnace respectively; the sodium hypophosphite was placed in the upwind direction and the nanorods D were placed in the downwind direction.

[0097] In a high-purity nitrogen atmosphere, the heating rate was set to 2°C / min, and after the temperature reached 250°C, constant temperature heat treatment was performed for 2h.

[0098] After the reaction is completed, the non-metallic single-atom phosphorus-loaded manganese tetraoxide nanomaterial is obtained and is recorded as PSAC / Mn3O4.

[0099] The catalytic performance of the non-metallic single-atom phosphorus-supported manganese tetraoxide nanomaterial PSAC / Mn3O4 prepared in Example 3 was tested:

[0100] 0.1 g of PSAC / Mn3O4 prepared in this example was mixed evenly with 1 g of quartz sand, and then placed into a quartz tube with a length of 50 cm and a diameter of 8 mm.

[0101] Place the quartz tube in a fixed bed reactor, select a benzene concentration of 10ppm, a benzene flow rate of 25mL / min, and an ozone flow rate of 25mL / min. The test results are shown in the following table

[0102] Table 3

[0103]

[0104] Example 4: Preparation of non-metallic single-atom phosphorus-supported manganese tetraoxide nanomaterials

[0105] The aforementioned method first prepares manganese oxide nanorods with the (101) surface exposed, which are denoted as nanorods D and will not be described in detail here.

[0106] 0.3 g of the prepared manganese oxide nanorods D and 2 g of sodium hypophosphite were placed in two porcelain boats of a tube furnace respectively; the sodium hypophosphite was placed in the upwind direction and the nanorods D were placed in the downwind direction.

[0107] In a high-purity nitrogen atmosphere, the heating rate was set to 2°C / min, and after the temperature reached 350°C, constant temperature heat treatment was performed for 2 hours.

[0108] After the reaction is completed, the non-metallic single-atom phosphorus-loaded manganese tetraoxide nanomaterial is obtained and is recorded as PSAC / Mn3O4.

[0109] The catalytic performance of the non-metallic single-atom phosphorus-supported manganese tetraoxide nanomaterial PSAC / Mn3O4 prepared in Example 4 was tested:

[0110] 0.1 g of PSAC / Mn3O4 prepared in this example was mixed evenly with 1 g of quartz sand, and then placed into a quartz tube with a length of 50 cm and a diameter of 8 mm.

[0111] Place the quartz tube in a fixed bed reactor, select a benzene concentration of 10ppm, a benzene flow rate of 25mL / min, and an ozone flow rate of 25mL / min. The test results are shown in the following table

[0112] Table 4

[0113]

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a non-metallic single atom-loaded manganese oxide nanomaterial, characterized in that The following steps are involved: The manganese oxide nanorods with the (101) crystal plane exposed are denoted as nanorods D. 0.3 g of the manganese oxide nanorods D and 1 to 2 g of sodium hypophosphite are placed in two porcelain boats of a tubular furnace respectively; the sodium hypophosphite is placed in the upwind direction and the nanorods D are placed in the downwind direction; in a high-purity nitrogen atmosphere, the heating rate is set to 2°C / min, and after the temperature reaches 250 to 350°C, constant temperature heat treatment is performed for 2 hours; after the reaction is completed, a non-metallic single-atom phosphorus-loaded manganese oxide nanomaterial is obtained.

2. The method for preparing the non-metallic single atom-supported manganese oxide nanomaterial according to claim 1, wherein The preparation of the manganese oxide nanorods with the (101) crystal surface exposed comprises the following steps: Step 1: Dissolve 0.237 g of pure potassium permanganate in 60 mL of ultrapure water and stir continuously until completely dissolved to obtain Solution A. Step 2: Slowly add 1.5 mL of ethylene glycol dropwise to solution A prepared in step 1 and stir evenly for 1 hour to obtain solution B; Step 3: Transfer the solution B prepared in step 2 to a polytetrafluoroethylene-lined reactor and heat at 120°C for 6 hours; Step 4: After the reaction in step 3 is completed, the precipitated material is washed and then slowly dried to obtain precursor C; Step 5: Place 0.35 g of precursor C in a porcelain boat in a tubular furnace and heat treat it at 450°C for 4 h in a high-purity argon atmosphere with a heating rate of 5°C / min. After the reaction is completed, manganese oxide nanorods with the (101) surface exposed are obtained.

3. The method for preparing the non-metallic single atom-supported manganese oxide nanomaterial according to claim 1 or 2, wherein: In the non-metallic single-atom phosphorus-loaded manganese oxide nanomaterial, the phosphorus atom exists above the middle of the manganese atom and the oxygen atom on the (101) crystal plane, coordinates with the manganese atom and the oxygen atom at the same time, and the phosphorus atom is evenly distributed on the surface of the manganese oxide.

4. The method for preparing the non-metallic single atom-supported manganese oxide nanomaterial according to claim 3, wherein: In the non-metallic single-atom phosphorus-loaded manganese manganese oxide nanomaterial, the loading amount of phosphorus is 4 wt %.

5. A method for applying the non-metallic single atom-supported manganese oxide nanomaterial obtained by the preparation method according to any one of claims 1 to 4, characterized in that The following steps are involved: 0.1 g of the non-metallic single-atom phosphorus-loaded manganese tetraoxide nanomaterial is taken as a catalyst, mixed evenly with 1 g of quartz sand, and placed in a quartz tube of a fixed-bed reaction device; the quartz tube is then placed vertically, with the ozone and the gas to be catalyzed flowing from top to bottom.

6. The method for applying the non-metallic single atom-supported manganese oxide nanomaterial according to claim 5, wherein: The flow rate of the gas to be catalyzed is 25 mL / min, and the flow rate of ozone is 25 mL / min; under the reaction conditions of 60 minutes at 50°C, the gas to be catalyzed can be completely oxidized by ozone activated by non-metallic single-atom phosphorus-loaded manganese dioxide nanomaterials.

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