Monatomic manganese / hydrogenated graphdiyne catalyst as well as preparation method and application thereof

Abstract

The invention discloses a monatomic manganese / hydrogenated graphdiyne catalyst and a preparation method and application thereof, and belongs to the technical field of catalysts.The preparation method comprises the following steps that a manganese salt solution and hydrogenated graphdiyne dispersion liquid are mixed, stirred and reacted, a solvent is removed after the reaction is finished, and the monatomic manganese / hydrogenated graphdiyne catalyst is obtained. The invention also discloses the monatomic manganese / hydrogenated graphdiyne catalyst prepared by the preparation method and application of the monatomic manganese / hydrogenated graphdiyne catalyst in photothermal catalytic oxidation decomposition of VOCs (Volatile Organic Compounds). The atomic-scale dispersed Mn / HsGDY catalyst is efficiently synthesized through a simple impregnation method, and the method is simple and efficient and can be applied to industrial large-scale preparation.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts, and in particular relates to a single-atom manganese / graphene hydrogenation catalyst and a preparation method and application thereof. Background Art

[0002] Volatile organic compounds, commonly referred to as VOCs, are usually divided into several categories, including non-methane hydrocarbons (NMHCs), oxygen-containing organic compounds, halogenated hydrocarbons, nitrogen-containing organic compounds, and sulfur-containing organic compounds. In recent years, many pollutant control technologies have been developed: such as thermal oxidation, non-thermal plasma, photocatalytic oxidation, and catalytic combustion, among which catalytic combustion is one of the most widely used technologies. However, the processing temperature of industrial catalytic combustion needs to be completed at 500-800°C, which greatly increases the energy consumption and economic cost of the catalytic combustion process; the catalyst is also easily deactivated due to high-temperature sintering; the high-temperature catalytic process also brings greater safety risks to petrochemical production.

[0003] Therefore, traditional industrial VOCs treatment technology can no longer meet the green and sustainable development needs of enterprises and society. How to provide a low-energy and low-cost catalytic oxidation method for volatile organic compounds is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a single-atom manganese / graphene hydrogenation catalyst and a preparation method and application thereof.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing a single-atom manganese / graphene hydrogenation catalyst comprises the following steps:

[0007] The manganese salt solution is added dropwise into the hydrogenated graphene dispersion liquid and mixed and stirred for reaction. After the reaction is completed, the solvent is removed to obtain the single atom manganese / hydrogenated graphene catalyst.

[0008] Beneficial effects: The present invention achieves atomic-level monodispersion of metal manganese on the carrier hydrogenated graphene through the strategy of dropwise addition method for loading metal atoms and low-temperature drying, thereby successfully avoiding the agglomeration of metal Mn on the surface of the prepared hydrogenated graphene-based catalyst.

[0009] Preferably, the concentration of the manganese salt solution is 1-3 mg / mL.

[0010] Preferably, the manganese salt in the manganese salt solution is one or any combination of manganese nitrate, manganese chloride, manganese acetate and corresponding hydrates.

[0011] Preferably, the solvent in the manganese salt solution is one of methanol, ethanol, ammonia water and water, and more preferably an ethanol solution with a purity of 99.5%.

[0012] Preferably, the concentration of the hydrogenated graphene dispersion is 1.5-5 mg / mL.

[0013] Preferably, the solvent in the hydrogenated graphene dispersion is one of methanol, ethanol, ammonia and water, and more preferably an ethanol solution with a purity of 99.5%.

[0014] Preferably, the reaction temperature is room temperature and the reaction time is 2 hours.

[0015] Preferably, the method for removing the solvent is to place the product in an oven for drying, and the drying temperature is 50-60° C. and the drying time is 12-18 hours.

[0016] A single-atom manganese / hydrogenated graphene catalyst is prepared by a method for preparing a single-atom manganese / hydrogenated graphene catalyst.

[0017] Preferably, the manganese atoms in the single-atom manganese / graphene hydrogenation catalyst are in a monodisperse state.

[0018] Preferably, the manganese atom exists in the form of a divalent manganese atom.

[0019] Application of a single-atom manganese / graphene hydrogenation catalyst in room temperature photothermal catalytic oxidation decomposition of VOCs.

[0020] Preferably, the VOCs is ethyl acetate.

[0021] Compared with the prior art, the present invention has the following advantages and technical effects:

[0022] The present invention efficiently synthesizes atomic-level dispersed SA Mn / HsGDY catalysts by a simple impregnation method, and successfully applies the atomic-level dispersed Mn / HsGDY catalysts to the photothermal catalytic oxidation of ethyl acetate. The obtained catalyst exhibits 100% catalytic activity at room temperature and 10 cycles of stability. In addition, the method provided by the present invention is simple and efficient and can be applied to industrial large-scale preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0024] Figure 1 The scanning electron microscope image and element distribution map of the single-atom manganese / graphene hydrogenation catalyst obtained in Example 1 of the present invention;

[0025] Figure 2The XRD patterns of the single-atom manganese / graphene hydrogenated catalyst and graphene hydrogenated obtained in Example 1 of the present invention;

[0026] Figure 3 The Raman graphs of the single-atom manganese / graphene hydrogenation catalyst and graphene hydrogenation obtained in Example 1 of the present invention;

[0027] Figure 4 The XPS spectrum of the single-atom manganese / graphene hydrogenation catalyst of the present invention;

[0028] Figure 5 The single-atom manganese / graphene hydrogenation catalyst obtained in Example 1 of the present invention and the activity curve of the photothermal catalytic oxidation decomposition of ethyl acetate by graphene hydrogenation;

[0029] Figure 6 This is a graph showing the 10-cycle (80 min per cycle) cyclic stability test of the single-atom manganese / graphene hydrogenation catalyst of the present invention;

[0030] Figure 7 This is an activity curve diagram of the photothermal catalytic oxidation decomposition of ethyl acetate by the single-atom manganese / carbon nanotube catalyst obtained in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] The present invention provides a method for preparing a single-atom manganese / graphene hydrogenation catalyst, comprising the following steps:

[0034] The manganese salt solution is added dropwise to the hydrogenated graphene dispersion liquid and mixed and stirred for reaction. After the reaction is completed, the solvent is removed to obtain the single atom manganese / hydrogenated graphene catalyst.

[0035] In a preferred embodiment, the concentration of the manganese salt solution is 1-3 mg / mL. If the concentration is higher than this, uneven metal loading will result, and if the concentration is lower than this, large errors in metal loading will result.

[0036] In a preferred embodiment, the manganese salt in the manganese salt solution is one or any combination of manganese nitrate, manganese chloride, manganese acetate and corresponding hydrates.

[0037] In a preferred embodiment, the solvent in the manganese salt solution is one of methanol, ethanol, ammonia water and water, and more preferably, the purity is 99.5% ethanol solution.

[0038] In a preferred embodiment, the concentration of the hydrogenated Graphene dispersion is 1.5-5 mg / mL. If the concentration is higher than this, the hydrogenated Graphene will be unevenly dispersed, and if the concentration is lower than this, the carrier mass error will be large.

[0039] In a preferred embodiment, the solvent in the hydrogenated graphene dispersion is one of methanol, ethanol, ammonia and water, and more preferably an ethanol solution with a purity of 99.5%.

[0040] In a preferred embodiment, the reaction temperature is room temperature and the reaction time is 2 hours. If the reaction temperature is too high, the surface structure of the catalyst will be destroyed, if it is too low, the interaction between the metal and the catalyst will be weak, if the reaction time is higher than the above conditions, the metal will agglomerate, and if it is lower than the above conditions, the metal loading will be insufficient.

[0041] In a preferred embodiment, the method for removing the solvent is to place the mixture in an oven for drying, wherein the drying temperature is 50-60° C. and the drying time is 12-18 hours.

[0042] The embodiment of the present invention also provides a single-atom manganese / graphene hydrogenated catalyst prepared by a method for preparing a single-atom manganese / graphene hydrogenated catalyst.

[0043] In a preferred embodiment, the manganese atoms in the single-atom manganese / graphene hydrogenation catalyst are in a monodisperse state.

[0044] In a preferred embodiment, the manganese atom exists in the form of a divalent manganese atom.

[0045] The embodiment of the present invention also provides an application of a single-atom manganese / graphene hydrogenation catalyst in room temperature photothermal catalytic oxidation decomposition of VOCs.

[0046] In a preferred embodiment, the VOCs is ethyl acetate.

[0047] Unless otherwise specified, the raw materials in the examples of the present invention were purchased from commercial sources;

[0048] The hydrogenated graphene monomer 1,3,5-triethynylbenzene raw material was purchased from a MacLean reagent supplier, and the preparation method of hydrogenated graphene powder is as follows:

[0049] First, 600 mg of hydrogenated graphene monomer was weighed and dissolved in 100 mL of pyridine solution. The solution was placed in a 250 mL constant pressure dropping funnel for standby use. Another 500 mL three-necked flask was placed, 20-30 copper coils with a diameter of about 1.5 cm were placed, 150 mL of pyridine solution was poured in, and the mixture was placed in an oil bath at 110°C for heating. At the same time, the solution in the constant pressure dropping funnel was dripped into the three-necked flask at a rate of 3 drops / second. After 3 days of reaction, the solution was filtered and washed with DMF, anhydrous ethanol, distilled water, and acetone until the washing liquid was colorless. The obtained coarse powder was boiled at 80°C for 6 hours with 60 mL of 2M hydrochloric acid. After the end, the solution was filtered and washed with DMF, anhydrous ethanol, distilled water, and acetone until the washing liquid was colorless. The obtained powder was calcined at 400°C in a N2 atmosphere for 6 hours to obtain the final hydrogenated graphene powder catalyst.

[0050] Unless otherwise specified, the room temperature or normal temperature in the embodiments of the present invention refers to 25±3°C.

[0051] Example 1

[0052] A method for preparing a single-atom manganese / graphene hydrogenation catalyst comprises the following steps:

[0053] (1) Weigh 100 mg of hydrogenated graphene powder and add it to a 50 mL beaker A, and add a stirrer. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker A. After stirring for 5 minutes, the hydrogenated graphene powder is evenly dispersed to obtain solution A, which is transferred to a magnetic stirrer and stirred at room temperature at a speed of 500-800 rpm for later use;

[0054] (2) Weigh 31.0 mg of manganese nitrate tetrahydrate (Mn(NO3)2·4H2O) and quickly add it to a 50 mL beaker B. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker B. Then, the solution is evenly dispersed under ultrasonic conditions for 2 min to obtain a manganese nitrate ethanol solution.

[0055] (3) Under stirring conditions, the manganese nitrate ethanol solution is added dropwise to solution A using a rubber-tipped dropper or a syringe pump, and the reaction is stirred for 2 h at room temperature to obtain a dispersion C. At this time, the metallic manganese has been successfully loaded on the hydrogenated graphene carrier; the magnetic stirrer is removed, and the dispersion C is transferred to an oven and dried at a constant temperature of 60°C for 12 h. After the ethanol is completely evaporated, a dry single-atom manganese hydrogenated graphene-based catalyst is obtained as a black solid, which is recorded as SAMn / HsGDY.

[0056] Example 2

[0057] A method for preparing a single-atom manganese / graphene hydrogenation catalyst comprises the following steps:

[0058] (1) Weigh 100 mg of hydrogenated graphene powder and add it to a 50 mL beaker A, and add a stirrer. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker A. After stirring for 5 minutes, the hydrogenated graphene powder is evenly dispersed to obtain solution A, which is transferred to a magnetic stirrer and stirred at room temperature at a speed of 500-800 rpm for later use;

[0059] (2) Weigh 31.0 mg of manganese chloride and quickly add it to a 50 mL beaker B. Then use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker B. Then, disperse it evenly under ultrasonic conditions for 2 minutes to obtain a manganese nitrate ethanol solution.

[0060] (3) Add the manganese nitrate ethanol solution dropwise into solution A using a rubber-tipped dropper or a syringe pump under stirring, and stir the reaction for 2 h at room temperature to obtain dispersion C. At this time, the metallic manganese has been successfully loaded on the hydrogenated graphene carrier; remove the magnetic stirrer, transfer the dispersion C to an oven and dry it at a constant temperature of 50-60°C for 12 h, and wait until the ethanol is completely evaporated to obtain a dry single-atom manganese hydrogenated graphene-based catalyst.

[0061] Example 3

[0062] A method for preparing a single-atom manganese / graphene hydrogenation catalyst comprises the following steps:

[0063] (1) Weigh 100 mg of hydrogenated graphene powder and add it to a 50 mL beaker A, and add a stirrer. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker A. After stirring for 5 minutes, the hydrogenated graphene powder is evenly dispersed to obtain solution A, which is transferred to a magnetic stirrer and stirred at room temperature at a speed of 500-800 rpm for later use;

[0064] (2) Weigh 31.0 mg of manganese acetate and quickly add it to a 50 mL beaker B. Then use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker B. Then, evenly disperse it under ultrasonic conditions for 2 minutes to obtain a manganese nitrate ethanol solution.

[0065] (3) Add the manganese nitrate ethanol solution dropwise into solution A using a rubber-tipped dropper or a syringe pump under stirring, and stir the reaction for 2 h at room temperature to obtain dispersion C. At this time, the metallic manganese has been successfully loaded on the hydrogenated graphene carrier; remove the magnetic stirrer, transfer the dispersion C to an oven and dry it at a constant temperature of 50-60°C for 12 h, and wait until the ethanol is completely evaporated to obtain a dry single-atom manganese hydrogenated graphene-based catalyst.

[0066] Example 4

[0067] A method for preparing a single-atom manganese / graphene hydrogenation catalyst comprises the following steps:

[0068] (1) Weigh 60 mg of hydrogenated graphene powder and add it to a 50 mL beaker A, and add a stirrer. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker A. After stirring for 5 minutes, the hydrogenated graphene powder is evenly dispersed to obtain solution A, which is transferred to a magnetic stirrer and stirred at 800 rpm at room temperature for later use;

[0069] (2) Weigh 31.0 mg of manganese nitrate tetrahydrate (Mn(NO3)2·4H2O) and quickly add it to a 50 mL beaker B. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker B. Then, the solution is evenly dispersed under ultrasonic conditions for 2 min to obtain a manganese nitrate ethanol solution.

[0070] (3) Add the manganese nitrate ethanol solution dropwise into solution A using a rubber-tipped dropper or a syringe pump under stirring, and stir the reaction for 2 h at room temperature to obtain dispersion C. At this time, the metallic manganese has been successfully loaded on the hydrogenated graphene carrier; remove the magnetic stirrer, transfer the dispersion C to an oven and dry it at a constant temperature of 50-60°C for 12 h, and wait until the ethanol is completely evaporated to obtain a dry single-atom manganese hydrogenated graphene-based catalyst.

[0071] Example 5

[0072] A method for preparing a single-atom manganese / graphene hydrogenation catalyst comprises the following steps:

[0073] (1) 80 mg of hydrogenated graphene powder was weighed and added to a 50 mL beaker A, and a stirring bar was added. Subsequently, 20 mL of ethanol solution (purity of 99.5%) was measured with a 50 mL measuring cylinder and added to beaker A. After stirring for 5 min, the hydrogenated graphene powder was evenly dispersed to obtain solution A, which was transferred to a magnetic stirrer and stirred at room temperature at a speed of 500-800 rpm for later use;

[0074] (2) Weigh 31.0 mg of manganese nitrate tetrahydrate (Mn(NO3)2·4H2O) and quickly add it to a 50 mL beaker B. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker B. Then, the solution is evenly dispersed under ultrasonic conditions for 2 min to obtain a manganese nitrate ethanol solution.

[0075] (3) Add the manganese nitrate ethanol solution dropwise into solution A using a rubber-tipped dropper or a syringe pump under stirring, and stir the reaction for 2 h at room temperature to obtain dispersion C. At this time, the metallic manganese has been successfully loaded on the hydrogenated graphene carrier; remove the magnetic stirrer, transfer the dispersion C to an oven and dry it at a constant temperature of 50-60°C for 12 h, and wait until the ethanol is completely evaporated to obtain a dry single-atom manganese hydrogenated graphene-based catalyst.

[0076] Example 6

[0077] A method for preparing a single-atom manganese / graphene hydrogenation catalyst comprises the following steps:

[0078] (1) Weigh 100 mg of hydrogenated graphene powder and add it to a 50 mL beaker A, and add a stirrer. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker A. After stirring for 5 minutes, the hydrogenated graphene powder is evenly dispersed to obtain solution A, which is transferred to a magnetic stirrer and stirred at room temperature at a speed of 500-800 rpm for later use;

[0079] (2) Weigh 40.0 mg of manganese nitrate tetrahydrate (Mn(NO3)2·4H2O) and quickly add it to a 50 mL beaker B. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker B. Then, the solution is evenly dispersed under ultrasonic conditions for 2 min to obtain a manganese nitrate ethanol solution.

[0080] (3) Add the manganese nitrate ethanol solution dropwise into solution A using a rubber-tipped dropper or a syringe pump under stirring, and stir the reaction for 2 h at room temperature to obtain dispersion C. At this time, the metallic manganese has been successfully loaded on the hydrogenated graphene carrier; remove the magnetic stirrer, transfer the dispersion C to an oven and dry it at a constant temperature of 50-60°C for 12 h, and wait until the ethanol is completely evaporated to obtain a dry single-atom manganese hydrogenated graphene-based catalyst.

[0081] Example 7

[0082] A method for preparing a single-atom manganese / graphene hydrogenation catalyst comprises the following steps:

[0083] (1) Weigh 100 mg of hydrogenated graphene powder and add it to a 50 mL beaker A, and add a stirrer. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker A. After stirring for 5 minutes, the hydrogenated graphene powder is evenly dispersed to obtain solution A, which is transferred to a magnetic stirrer and stirred at room temperature at a speed of 500-800 rpm for later use;

[0084] (2) Weigh 60.0 mg of manganese nitrate tetrahydrate (Mn(NO3)2·4H2O) and quickly add it to a 50 mL beaker B. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker B. Then, the solution is evenly dispersed under ultrasonic conditions for 2 min to obtain a manganese nitrate ethanol solution.

[0085] (3) Under stirring conditions, the manganese nitrate ethanol solution is added dropwise to solution A using a rubber-tipped dropper or a syringe pump, and the reaction is stirred for 2 h at room temperature to obtain a dispersion C. At this time, the metallic manganese has been successfully loaded on the hydrogenated graphene carrier; the magnetic stirrer is removed, and the dispersion C is transferred to an oven and dried at a constant temperature of 60°C for 12 h. When the ethanol is completely evaporated, a dry single-atom manganese hydrogenated graphene-based catalyst is obtained.

[0086] Comparative Example 1

[0087] A method for preparing an atomically dispersed manganese carbon nanotube catalyst (SAMn / CNT) comprises the following steps:

[0088] (1) Weigh 100 mg of carbon nanotubes and add them to a 50 mL beaker A, add a stirrer, then use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker A, stir for 5 min to evenly disperse the carbon nanotube powder, and obtain solution A, which is then transferred to a magnetic stirrer and stirred at a speed of 500-800 rpm for later use;

[0089] (2) Weigh 31.0 mg of manganese nitrate tetrahydrate (Mn(NO3)2·4H2O) and quickly add it to a 50 mL beaker B. Then, use a 50 mL measuring cylinder to measure 20 mL of ethanol solution (purity of 99.5%) and add it to beaker B. Then, the solution is evenly dispersed under ultrasonic conditions for 2 min to obtain a manganese salt solution.

[0090] (3) Under stirring conditions, the manganese salt solution is added dropwise to solution A using a rubber-tipped dropper or a syringe pump, and the reaction is stirred for 2 hours at room temperature to obtain a dispersion C. At this time, the metallic manganese has been successfully loaded on the carbon nanotube carrier; the magnetic stirrer is removed, and the dispersion C is transferred to an oven and dried at a constant temperature of 60°C for 12 hours. When the ethanol is completely evaporated, a dry single-atom manganese carbon nanotube catalyst (SA Mn / CNT) is obtained.

[0091] Technical effects:

[0092] 1. Performance Characterization

[0093] The single atom manganese hydrogenated graphene-based catalyst (SAMn / HsGDY) obtained in Example 1 was subjected to the following Figure 1-4 Characterization of catalyst structure and morphology.

[0094] from Figure 1 The scanning electron microscope image shows that the prepared single-atom manganese hydrogenation graphene-based catalyst sample is in a spherical cluster aggregation state;

[0095] If the peaks corresponding to the crystal structure are detected in XRD, it proves that nanoparticles or nanoparticles exist in the material. Figure 2 The XRD graph of the catalyst does not show the characteristic peak of Mn metal, indicating that there are no nanoparticles in the product obtained by the present invention, and the metal is anchored on the surface of the catalyst support in a highly dispersed state, that is, the metal manganese in the catalyst obtained by the present invention is in an atomically monodispersed state, proving that the atomically dispersed Mn / graphene hydrogenation catalyst is successfully prepared;

[0096] Depend on Figure 3 The Raman spectrum also further confirmed that the manganese atoms in the catalyst were monodispersed and the structure of hydrogenated Graphyne did not change;

[0097] Figure 4 The XPS spectrum shows that the manganese atoms on the surface of the catalyst exist in the form of divalent manganese atoms, and further proves that the manganese metal is successfully loaded on the hydrogenated graphene carrier.

[0098] 2. Catalytic oxidation decomposition activity

[0099] In order to further verify the advantages of single-atom Mn / hydrogenated graphene catalyst in the field of VOCs degradation, single-atom manganese / hydrogenated graphene-based catalyst was applied to the room temperature photothermal catalytic oxidation decomposition activity test of ethyl acetate, and hydrogenated graphene raw material (HsGDY) was used as a control group for the same test to compare with the present invention. The selected test conditions are: the test gas is ethyl acetate, and the concentration of the mixed gas cylinder is 500ppm. In a quartz tube glass reactor with an inner diameter of 6mm and an outer diameter of 8mm at the inlet and outlet, and the area of ​​the reactor receiving light area is 10mm*10mm, 100mg of the catalyst obtained in Example 1 is loaded, the total gas flow rate is controlled to 100mL / min, and the volume space velocity is 30000mL g -1 h -1 , where the oxygen flow rate is 10mL / min, the N2 as a balance gas flow rate is 30mL / min, and the ethyl acetate gas flow rate is 10mL / min. The ethyl acetate concentration in the tail gas is detected and analyzed by gas chromatography. The reaction temperature during the test was room temperature (25°C) and the humidity was 30%. The catalyst stability test conditions were consistent with the above-mentioned activity test conditions, except that the performance test was repeated 10 times. The results are as follows Figure 5-6 shown.

[0100] from Figure 5From the comparison of the activity curves of different catalysts, it can be seen that the single-atom manganese / graphene hydrogenated catalyst exhibits 100% photothermal catalytic oxidation activity for ethyl acetate at room temperature. Figure 6 The catalyst stability test results shown in the figure show that the single-atom manganese / graphene hydrogenation catalyst shows good stability and can still maintain nearly 100% ethyl acetate decomposition activity after 10 catalyst cycle tests. However, the ethyl acetate photothermal catalytic oxidation activity of the comparative sample SAMn / CNT is only about 40%.

[0101] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for preparing a single-atom manganese / graphene hydrogenation catalyst, characterized in that: The following steps are involved: The manganese salt solution is added dropwise to the hydrogenated graphene dispersion liquid and mixed and stirred for reaction. After the reaction is completed, the solvent is removed to obtain the single atom manganese / hydrogenated graphene catalyst.

2. The method for preparing a single-atom manganese / graphene hydrogenation catalyst according to claim 1, characterized in that: The concentration of the manganese salt solution is 1-3 mg / mL.

3. The method for preparing a single-atom manganese / graphene hydrogenation catalyst according to claim 1, characterized in that: The manganese salt in the manganese salt solution is one or any combination of manganese nitrate, manganese chloride, manganese acetate and corresponding hydrates.

4. The method for preparing a single-atom manganese / graphene hydrogenation catalyst according to claim 1, characterized in that: The concentration of the hydrogenated graphene dispersion is 1.5-5 mg / mL.

5. The method for preparing a single-atom manganese / graphene hydrogenation catalyst according to claim 1, characterized in that: The reaction time is 2h.

6. The single-atom manganese / graphene hydrogenation catalyst prepared by the preparation method according to claim 1.

7. The single-atom manganese / graphene hydrogenation catalyst according to claim 1, characterized in that: The manganese atoms in the single-atom manganese / graphene hydrogenation catalyst are in a monodisperse state.

8. The single-atom manganese / graphene hydrogenation catalyst according to claim 1, characterized in that: The manganese atom exists in the form of a divalent manganese atom.

9. Use of the single-atom manganese / graphene hydrogenated catalyst as described in any one of claims 6 to 8 in photothermal catalytic oxidation decomposition of VOCs.

10. The use according to claim 9, characterized in that: The VOCs is ethyl acetate.

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