Organic carbon source modified multifunctional metal oxidizing agent FeMn as well as preparation and application thereof

Abstract

The invention discloses an organic carbon source modified multifunctional metal oxidizing agent FeMn as well as preparation and application thereof. The preparation method comprises the following steps: carrying out step-by-step hydrothermal reaction on a mixed solution containing an iron-based metal precursor, a manganese-based metal precursor and an organic carbon source; and roasting a product obtained by the hydrothermal reaction to obtain the organic carbon source modified multifunctional metal oxidant FeMn. According to the invention, Fe and Mn composite metal oxide is taken as an active component, soluble sugar is introduced, a carbonization process of the soluble sugar and a crystallization process of the active component in a hydrothermal process are combined, a step-by-step hydrothermal mode is adopted, the monolithic catalyst with colloidal carbon wrapped by the metal oxide is constructed, and then the roasting atmosphere type is adjusted, so that the metal oxide-coated colloidal carbon is obtained. Similarly, a monolithic catalyst with a controllable internal cavity is formed. The preparation method of the catalyst is simple, the used raw materials are cheap and easy to obtain, the catalyst is easy to popularize, and the catalyst shows excellent low-temperature oxidation activity on different aromatic VOCs.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of chemical catalyst synthesis and its application, and particularly relates to a multifunctional metal oxidant FeMn modified by an organic carbon source and preparation and application thereof. BACKGROUND

[0002] Volatile organic compounds (VOCs) are precursors of ozone and PM 2.5 , which can interact with NO x in the atmosphere to form secondary pollution such as organic aerosols and haze, and thus cause serious harm to the natural environment and human health. In order to reduce the pollution of PM 2.5 and O3 in the air, it is crucial to reduce the emission of aromatic VOCs, and therefore, the treatment of industrial VOCs, especially aromatic VOCs, is urgent.

[0003] Among the numerous VOCs treatment technologies, catalytic oxidation technology has the advantages of high treatment efficiency, less secondary pollution, and relatively simple operation, and has become a research hotspot, and the research and development of high-efficiency catalysts is a key link in the research of catalytic oxidation technology. According to the differences in catalyst carriers and active components, catalysts can be divided into supported catalysts and metal oxide catalysts. Since VOCs have the characteristics of various types, unstable working conditions, and intermittent production, the ring-opening process of benzene is the rate-determining step of aromatic VOCs oxidation, and therefore, it is of great significance to study complex aromatic hydrocarbons (toluene, styrene) as representative pollutants of VOCs. At present, the widely used VOCs catalysts in the market are mostly supported noble metal catalysts and metal oxide catalysts, for example, using cordierite, molecular sieve, carbon-based materials, etc. as the support and using metal oxides Fe, Mn, Cu, Ce, etc. as the active component, the best temperature window for VOCs oxidation is 260-320 ℃; and using noble metals (Ru, Pt, etc.) as the active component, the best temperature window for VOCs oxidation is 150-250 ℃. Therefore, supported noble metal catalysts generally have good low-temperature oxidation activity.

[0004] The Chinese patent application with the publication number CN 110479261 A discloses a VOCs catalytic oxidation supported catalyst and a preparation method thereof, taking noble metal Pt as an active component, and taking a cordierite substrate growing TiO2 nanometer array as a main carrier, and the conversion rate of toluene can reach more than 98% under the condition of 240 DEG C; the Chinese patent application with the publication number CN 113210006 A discloses a preparation method of a catalytic combustion VOCs monolithic composite metal oxide catalyst, taking manganese dioxide, cerium oxide, copper oxide and the like as active components, and taking a honeycomb ceramic as a carrier, and a monolithic catalyst is prepared, and the conversion efficiency of VOCs can reach 98% under the condition of 350 DEG C; and the Chinese patent application with the publication number CN 113019368 A discloses a cobalt-containing mesoporous silica nanosphere catalyst and a preparation method and application thereof, taking divalent cobalt oxide as an important active component, and the purification rate of toluene can reach 99.9% at 291 DEG C. However, the supported noble metal catalyst has the disadvantages of high cost, poor resistance to poisoning, difficulty in obtaining, and inability to be applied in large-scale engineering, and the metal oxide catalyst has the disadvantages of high optimal active temperature window and poor resistance. In addition, most of the catalytic oxidation researches only consider the catalytic oxidation of a single VOCs component, and the influence of composite VOCs and gases such as SO2, H2O and HCl on the catalyst is not explored. Therefore, it is the key to develop a low-temperature and high-efficiency metal oxide catalyst for removing aromatic VOCs under complex working conditions. SUMMARY

[0005] The primary purpose of the present application is to provide a preparation method of an organic carbon source modified multifunctional metal oxidant FeMn.

[0006] Another purpose of the present application is to provide an organic carbon source modified multifunctional metal oxidant FeMn.

[0007] Still another purpose of the present application is to provide the application of the above-mentioned organic carbon source modified multifunctional metal oxidant FeMn in atmospheric environmental pollutant treatment.

[0008] The purpose of the present application is achieved by the following technical solutions. A preparation method of an organic carbon source modified multifunctional metal oxidant FeMn, comprising the following steps: (1) mixing iron-based metal precursors, manganese-based metal precursors and water, fully stirring to dissolve them, forming a mixed solution, denoted as mixed solution A; (2) Dissolve the base in water, then add the organic carbon source, and fully stir to dissolve, denoted as mixed solution B; (3) Transfer the mixed solution B to the hydrothermal reactor, and after standing for a period of time, perform the first step of hydrothermal reaction. After the reaction is completed and the mixture is cooled, slowly add the mixed solution A into the hydrothermal reactor, fully mix with the formed organic carbon colloid solution, and then perform the second step of hydrothermal reaction; (4) Calcine the product obtained in step (3) to obtain the FeMn composite metal oxide catalyst, i.e. the multifunctional metal oxide FeMn modified by the organic carbon source.

[0009] Preferably, the iron-based metal precursor in step (1) is at least one of ferric nitrate, ferrocene, ferric chloride, ferric nitrate, ferric sulfate, and ferric acetate; and the manganese-based metal precursor is at least one of manganese acetate, manganese chloride, manganese sulfate, and manganese nitrate.

[0010] Preferably, an anionic surfactant is further added to the mixed solution in step (1), and the anionic surfactant is at least one of sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, and sodium alkyl benzene sulfonate; and the molar ratio of the anionic surfactant to the total amount of iron and manganese is 1:1.

[0011] Preferably, the temperature of the stirring in step (1) is 25-30°C, the stirring time is 20-40 min, and the stirring rate is 200-300 r / min.

[0012] Preferably, the organic carbon source in step (2) is at least one of soluble sugars such as glucose, sucrose, fructose, and maltose.

[0013] Preferably, the base in step (2) is at least one of weakly alkaline solutions such as ammonia, sodium carbonate, and urea, and the pH of the base solution is 9-11.

[0014] Preferably, the temperature of the stirring in step (2) is 25-30°C, the stirring time is 40-60 min, and the stirring rate is 100-200 r / min.

[0015] Preferably, in steps (1) and (2), the molar ratio of iron and manganese metal ions is (0-1):(0-8), and the molar ratio of the total amount of iron and manganese to the organic carbon is 1:(0-4).

[0016] More preferably, the molar ratio of iron and manganese metal ions is 1:8, and the molar ratio of the total amount of iron and manganese to the organic carbon is 1:1.

[0017] Preferably, the first step hydrothermal reaction temperature in step (3) is 100-120 DEG C, the hydrothermal time is 4-6 h, the second step hydrothermal reaction temperature is 150-180 DEG C, and the hydrothermal time is 12-18 h.

[0018] Preferably, after the second step hydrothermal reaction in step (3) is completed, the liquid is filtered to obtain a solid product, then washed with a water and ethanol mixture until neutral, and dried.

[0019] The drying temperature is 80-100 DEG C, and the drying time is 8-12 h.

[0020] Preferably, the atmosphere for the calcination in step (4) is one of a nitrogen and oxygen mixed atmosphere, and an ammonia atmosphere, and the proportion of oxygen in the nitrogen and oxygen mixed atmosphere is 0-20%.

[0021] More preferably, the atmosphere for the calcination in step (4) is preferably a nitrogen and oxygen mixed atmosphere, and the proportion of oxygen is 20%.

[0022] Preferably, the calcination temperature in step (4) is 300-600 DEG C, and the calcination time is 3-6 h.

[0023] The above-mentioned FeMn@C catalyst modified by an organic carbon source is mainly applied to the low-temperature oxidation of complex aromatic hydrocarbon VOCs. The types of the aromatic hydrocarbon VOCs exhaust gas include at least one of benzene, styrene, toluene, xylene, trimethylbenzene, ethylbenzene, etc.

[0024] Compared with the prior art, the present application has the following advantages and beneficial effects: (1) The present application introduces a colloidal carbon precursor into a FeMn composite metal oxide catalyst, innovatively controls the hydrothermal conditions to construct a whole type catalyst with metal oxide wrapping colloidal carbon, and then controls the formation of a core-shell structure catalyst with an internal cavity by adjusting the calcination atmosphere, thereby greatly increasing the specific surface area of the catalyst.

[0025] (2) The present application innovatively proposes a two-step hydrothermal method for preparing a FeMn composite metal oxide catalyst, which first forms an organic carbon sphere precursor from a carbon source, then adds an active component, performs crystal growth with the organic carbon sphere precursor as the core, and finally forms a high-activity FeMn composite metal oxide catalyst with controllable pores by the way of re-hydrothermal.

[0026] (3) The FeMn composite metal oxide catalyst prepared by the present application uses a hydrothermal method to prepare a whole type catalyst, which has the advantages of simple preparation method, stable reaction conditions, and strong controllability.

[0027] (4) The FeMn composite metal oxide catalyst prepared by the method has high specific surface area and adsorption performance, and greatly improves the specific surface area and pore structure of the integral catalyst, so that the catalyst has good low-temperature activity and selectivity in the oxidation process of aromatic hydrocarbon VOCs. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a styrene (A) and carbon dioxide (B) degradation efficiency curve diagram of the catalyst prepared in the embodiment 1, 2, 3, 4 and 5 of the application.

[0029] Figure 2 is a nitrogen adsorption and desorption curve diagram of the catalyst prepared in the embodiment 4, 8 and 10 of the application.

[0030] Figure 3 is a styrene degradation efficiency curve diagram of the catalyst prepared in the embodiment 4, 8, 10, 11 and 12 of the application.

[0031] Figure 4 is a styrene degradation efficiency curve diagram of the catalyst prepared in the embodiment 4, 6 and 7 of the application.

[0032] Figure 5 is a degradation efficiency curve diagram of the catalyst prepared in the embodiment 4 of the application for different types of pollutants.

[0033] Figure 6 is a degradation efficiency curve diagram of the catalyst prepared in the embodiment 14 of the application for styrene.

[0034] Figure 7 is a degradation efficiency curve diagram of the catalyst prepared in the embodiment 4 and the embodiment 15 of the application for styrene. DETAILED DESCRIPTION

[0035] The application will be further described in detail below in combination with the embodiments and the drawings, but the embodiments of the application are not limited thereto. The raw materials involved in the application can be directly purchased from the market. For the process parameters not specially mentioned, the conventional techniques can be referred to.

[0036] The particle size of the catalyst used in the following embodiments for activity evaluation is 40-60 mesh.

[0037] Embodiment 1 The preparation of a FeMn composite metal oxide catalyst is as follows: (1) 0.05 mol of iron nitrate and manganese acetate (the molar ratio of iron nitrate to manganese acetate is 1:0) is taken, and is dissolved in 50 mL of deionized water to form a mixed solution, which is recorded as mixed solution A; (2) 0.05 mol of glucose was dissolved in 50 mL of ammonia solution (2.5 mol / L, pH = 9-11) to prepare a mixed solution B; (3) After the mixed solution B was placed at room temperature for 2 h, it was transferred to a hydrothermal reactor, and hydrothermal reaction was carried out at 100°C for 4 h. After the hydrothermal reaction was completed and the solution was cooled to room temperature, solution A was slowly injected into the reactor, and hydrothermal reaction was carried out at 180°C for 8 h. Then, the solution was washed with a mixture of deionized water and ethanol until it was neutral, and was dried at 80°C for 12 h to obtain a solid sample; (4) The dried sample was placed in a tube furnace, and a roasting atmosphere (oxygen and nitrogen content ratio was 20%) was adjusted. The sample was roasted at 400°C for 4 h, and the obtained catalyst was recorded as Fe@C@0.2O2.

[0038] Example 2 This example is basically the same as Example 1, except that the molar ratio of iron nitrate and manganese acetate in step (1) of this example is 2:1, and the obtained catalyst is recorded as Fe2Mn1@C@0.2O2.

[0039] Example 3 This example is basically the same as Example 1, except that the molar ratio of iron nitrate and manganese acetate in step (1) of this example is 1:1, and the obtained catalyst is recorded as Fe1Mn1@C@0.2O2.

[0040] Example 4 This example is basically the same as Example 1, except that the molar ratio of iron nitrate and manganese acetate in step (1) of this example is 1:8, and the obtained catalyst is recorded as Fe1Mn8@C@0.2O2.

[0041] Example 5 This example is basically the same as Example 1, except that the molar ratio of iron nitrate and manganese acetate in step (1) of this example is 0:1, and the obtained catalyst is recorded as Mn@C@0.2O2.

[0042] Example 6 This example is basically the same as Example 4, except that the oxygen and nitrogen content ratio in step (4) of this example is 10%, and the obtained catalyst is recorded as Fe1Mn8@C@0.1O2.

[0043] Example 7 This example is basically the same as Example 4, except that the atmosphere in step (4) of this example is pure nitrogen, and the obtained catalyst is recorded as Fe1Mn8@C.

[0044] Example 8 This example is basically the same as Example 4, except that no glucose is added in step (2) in this example, and the catalyst prepared is denoted as Fe1Mn8@0.2O2.

[0045] Example 9 This example is basically the same as Example 4, except that the amount of glucose added in step (2) in this example is 0.0125 mol, i.e. (Fe+Mn):C=4:1, and the catalyst prepared is denoted as Fe1Mn8@0.25C@0.2O2.

[0046] Example 10 This example is basically the same as Example 4, except that the amount of glucose added in step (2) in this example is 0.025 mol, i.e. (Fe+Mn):C=2:1, and the catalyst prepared is denoted as Fe1Mn8@0.5C@0.2O2.

[0047] Example 11 This example is basically the same as Example 4, except that the amount of glucose added in step (2) in this example is 0.1 mol, i.e. (Fe+Mn):C=1:2, and the catalyst prepared is denoted as Fe1Mn8@2C@0.2O2.

[0048] Example 12 This example is basically the same as Example 4, except that the amount of glucose added in step (2) in this example is 0.2 mol, i.e. (Fe+Mn):C=1:4, and the catalyst prepared is denoted as Fe1Mn8@4C@0.2O2.

[0049] Example 13 This example is basically the same as Example 4, except that the calcination atmosphere in step (4) in this example is pure ammonia, and the catalyst prepared is denoted as Fe1Mn8@C@N.

[0050] Example 14 This example is basically the same as Example 4, except that the carbon sources added in step (2) in this example are glucose, fructose, maltose and starch, respectively, and the catalysts prepared are denoted as Fe1Mn8@P, Fe1Mn8@G, Fe1Mn8@M and Fe1Mn8@D, respectively.

[0051] Example 15 This example is basically the same as Example 4, except that a one-step hydrothermal method is used in step (3) in this example, and the catalyst prepared is denoted as Fe1Mn8-1@C@0.2O2.

[0052] Experimental Example 1 To further explore the influence of the active component ratio of the multifunctional FeMn@C catalyst on the oxidation performance of VOCs, the catalysts prepared in Examples 1, 2, 3, 4, and 5 were selected to compare and study the catalytic oxidation process of styrene. The specific experiment is as follows: about 0.24 g of the catalyst prepared in each of Examples 1, 2, 3, 4, and 5 was placed in a fixed-bed glass reaction tube, and the total flow rate was set to 80 mL / min. The activity test experiment was carried out under the conditions of a space velocity of 20000 h-1and a styrene concentration of 500 ppm, and the activity test results are shown in Table 2. -1 Figure 1 The activity test results show that the conversion rate of styrene gradually increases with the increase of the reaction temperature for all catalysts, and the temperature at which the styrene is completely converted conforms to the following order: Fe1Mn8@C@0.2O2>Mn@C@0.2O2>Fe1Mn1@C@0.2O2>Fe2Mn1@C@0.2O2>Fe@C@0.2O2. Among them, the catalyst Fe1Mn8@C@0.2O2 has the best low-temperature oxidation activity, and the complete degradation temperature of styrene is 260 ℃. This indicates that the increase of the manganese content can improve the low-temperature oxidation activity of the overall catalyst, and the oxidation activity of the FeMn overall catalyst is the best when Fe:Mn=1:8.

[0053] Experimental Example 2 To further explore the influence of different amounts of glucose added on the specific surface area and pore structure distribution of the FeMn@C catalyst, the catalysts prepared in Examples 4, 8, and 10 were selected for specific surface area analysis. The specific surface area, pore volume, and pore size distribution of the catalysts are shown in Table 1, and the N2adsorption-desorption isotherm is shown in Figure 2. According to the nitrogen adsorption-desorption curve, the adsorption-desorption curve of the catalysts prepared in Examples 4 and 10 belongs to the H3 type adsorption-desorption curve in VI, and the catalyst prepared in Example 8 belongs to the H4 type adsorption-desorption curve in VI. At the same time, by comparing the pore size and specific surface area of the three different catalysts, it is found that the specific surface area of the catalyst increases with the increase of the amount of organic carbon source added, indicating that the introduction of colloidal carbon can enrich the pore structure of the catalyst. Figure 2

[0054] Table 1 Specific surface area data of the catalysts prepared in Examples 4, 8, and 10

[0055] Experimental Example 3 To further explore the influence of the amount of glucose added on the VOCs oxidation activity of the FeMn@C catalyst, the catalysts prepared in Examples 4, 8, 10, 11, and 12 were selected as the research objects. The total flow rate was 80 mL / min, and the space velocity was 20000 h-1. The activity test results are shown in Table 2.​​-1 The oxidation activity of the catalyst was investigated under the condition of styrene concentration of 500 ppm. The experimental results are as follows: Figure 3 As shown, the addition of an appropriate amount of glucose can enhance the styrene oxidation activity of the FeMn@C catalyst to a certain extent. When (Fe+Mn):C=1:1, the catalyst can completely degrade styrene at 260 °C.

[0056] Experiment Example 4 To further investigate the effect of different calcination atmospheres on the specific surface area of ​​FeMn@C catalysts, the catalysts prepared in Examples 4, 6, and 7 were selected as the research objects. BET test results showed that the Fe1Mn8@C@0.2O2 catalyst had the largest specific surface area of ​​67.95 mg / m² when the calcination atmosphere was 20% O2. 3 The average pore size is 15.22 nm, and the pore volume is 0.259 mg / m³. 3 (As shown in Table 2) Table 2. Specific surface area data of catalysts prepared in Examples 4, 6, and 7.

[0057] Experimental Example 5 To further investigate the effects of different calcination atmospheres on the oxidation activity of FeMn@C catalysts, the catalysts prepared in Examples 4, 6, and 7 were used as the research objects in this experiment, with a total flow rate of 80 mL / min and a space velocity of 20000 h⁻¹. -1 The oxidation activity of the catalyst was measured under the condition of styrene concentration of 500 ppm, and the experimental results are as follows: Figure 4 As shown in the figure, the catalyst activity test results indicate that styrene can be completely converted under the Fe1Mn8@C@0.2O2 catalyst at 260 °C.

[0058] Experimental Example 6 To further investigate the oxidation activity of the FeMn@C catalyst for different types of aromatic VOCs, this experiment used the catalyst Fe1Mn8@C@0.2O2 prepared in Example 4, and tested it at a space velocity of 20000 h⁻¹. -1 The oxidation activity of the catalyst was tested under the conditions of 500 ppm toluene, 500 ppm styrene, 500 ppm xylene, 500 ppm trimethylbenzene, and a total flow rate of 80 mL / min. The experimental results are as follows: Figure 5 As shown, the Fe1Mn8@C@0.2O2 catalyst achieves complete conversion of toluene at a temperature of 240 °C, while under the same conditions, the complete conversion of styrene requires a temperature of 260 °C.

[0059] Experimental Example 7 In order to further explore the oxidation activity of FeMn catalysts prepared by different carbon sources on styrene, the catalysts Fe1Mn8@P, Fe1Mn8@G, Fe1Mn8@M and Fe1Mn8@D prepared in Example 14 were selected, and the oxidation activity of the catalysts was determined under the conditions of total flow 80 mL / min, space velocity 20000 h-1 and styrene concentration 500 ppm, and the experimental results are shown in Table 2. -1 According to the catalyst activity test results, it can be known that the catalytic activity of the FeMn catalyst prepared by using glucose as the carbon source is the highest, and the styrene can be completely degraded at 260℃. Figure 6

[0060] Experimental Example 8 In order to further explore the oxidation activity of FeMn catalysts prepared by one-step or two-step hydrothermal method on styrene, the catalyst Fe1Mn8-1@C@0.2O2 prepared in Example 15 and the catalyst Fe1Mn8@C@0.2O2 prepared in Example 4 were selected, and the oxidation activity of the catalysts was determined under the conditions of total flow 80 mL / min, space velocity 20000 h-1 and styrene concentration 500 ppm, and the experimental results are shown in Table 3. -1 According to the catalyst activity test results, it can be known that the catalytic activity of the FeMn catalyst prepared by the two-step hydrothermal method is the highest, and the styrene can be completely degraded at 260℃. Figure 7

[0061] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principles of the present application should be equivalent replacement methods, and all are included in the protection scope of the present application.​​

Claims

1. A method for preparing a multifunctional metal oxidant FeMn modified with an organic carbon source, characterized in that, Includes the following steps: (1) Mix the iron-based metal precursor and the manganese-based metal precursor with water and stir thoroughly to dissolve them to form a mixture, which is denoted as mixture A; (2) Dissolve the alkali in water, then add the organic carbon source and stir thoroughly to dissolve it completely. This mixture is called mixture B. (3) Transfer the mixture B to the hydrothermal reactor, let it stand for a period of time, and then carry out the first step of hydrothermal reaction. After the reaction is completed and the mixture is cooled, slowly add the mixture A into the hydrothermal reactor and mix it thoroughly with the formed organic carbon colloidal liquid. Then carry out the second step of hydrothermal reaction. (4) The product obtained in step (3) is roasted to obtain the multifunctional metal oxidant FeMn modified by the organic carbon source.

2. The preparation method according to claim 1, characterized in that, The iron-based metal precursor mentioned in step (1) is at least one of ferric nitrate, ferrocene, ferric chloride, ferric nitrate, ferric sulfate, and ferric acetate; the manganese-based metal precursor is at least one of manganese acetate, manganese chloride, manganese sulfate, and manganese nitrate.

3. The preparation method according to claim 1, characterized in that, The organic carbon source mentioned in step (2) is at least one of glucose, sucrose, fructose, and maltose; The alkali mentioned in step (2) is at least one of ammonia, sodium carbonate, and urea, and the pH of the alkali solution is 9-11.

4. The preparation method according to claim 1, characterized in that, In steps (1) and (2), the molar ratio of iron and manganese metal ions is (0~1):(0~8), preferably 1:8; the molar ratio of the total amount of iron and manganese metal to organic carbon is 1:(0~4), preferably 1:

1.

5. The preparation method according to claim 1, characterized in that, In step (1), an anionic surfactant is also added to the mixture. The anionic surfactant is at least one of sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, and sodium alkylbenzenesulfonate. The molar ratio of the anionic surfactant to the total amount of iron and manganese metal is 1:

1.

6. The preparation method according to claim 1, characterized in that, In step (3), the first hydrothermal reaction temperature is 100~120 ℃ and the hydrothermal time is 4~6 h, while the second hydrothermal reaction temperature is 150~180 ℃ and the hydrothermal time is 12~18 h.

7. The preparation method according to claim 1, characterized in that, The roasting atmosphere in step (4) is either a nitrogen-oxygen mixture atmosphere or an ammonia atmosphere, wherein the oxygen content in the nitrogen-oxygen mixture atmosphere is 0-20%; The roasting temperature in step (4) is 300~600 ℃ and the roasting time is 3~6 h.

8. The preparation method according to claim 1, characterized in that, The roasting atmosphere described in step (4) is a mixture of nitrogen and oxygen, wherein the oxygen content is 20%.

9. An organic carbon source-modified FeMn@C catalyst, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 8.

10. The application of the FeMn@C catalyst modified with an organic carbon source as described in claim 9, characterized in that, It is used for the low-temperature oxidation of complex aromatic hydrocarbon VOCs.

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