CN110385125A - A kind of potassium doping MnO2Catalyst and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of chemical catalysts, and specifically discloses a potassium-doped _MnO2 catalyst and a preparation method thereof. The preparation method comprises the following steps: adding the MnO ₂ precursor into the KOH solution, refluxing the reaction, drying and calcining the product to obtain the potassium-doped MnO ₂ catalyst. The preparation method provided by the invention has simple process and convenient operation. Using potassium permanganate and benzyl alcohol as raw materials, the KOH-OMS-2 catalyst doped with K ⁺ and -OH at the same time is prepared, and has catalytic combustion activity to VOCs organic waste gas Enhanced, low temperature processing efficiency is improved.

Description

A kind of potassium-doped MnO2 catalyst and preparation method thereof

technical field

The invention relates to the technical field of chemical catalysts, in particular to a potassium-doped _MnO2 catalyst and a preparation method thereof.

Background technique

At present, the primary task to solve the problem of VOCs pollution is to deal with benzene series pollutants. Existing methods for treating benzene series pollutants include catalytic oxidation, adsorption and absorption, biodegradation, photocatalytic oxidation, and plasma treatment. Among them, the catalytic oxidation method has been considered as the most promising treatment technology due to its outstanding advantage of fully converting VOCs into non-polluting CO ₂ and H ₂ O. The key point in the catalytic oxidation method is the choice of catalyst, and manganese oxide is the most common catalyst in this method.

There are many crystal forms of MnO ₂ , among which oxide octahedral molecular sieves (OMS-2) have long been used as highly active, low-cost, environmentally friendly catalysts for the removal of volatile organic compounds (VOCs). It has a porous structure, contains Mn species in mixed valence states, and in particular, it is hydrophobic, which improves its stability to water. Therefore, OMS-2 exhibited excellent performance in the catalytic oxidation of VOCs. Related studies have found that doping KOH or alkali metal K into MnO ₂ can improve the catalytic activity. At present, the preparation methods of K ⁺ modified _MnO2 mainly include impregnation method, hydrothermal method and solid grinding method, etc. However, the preparation process of the prior art is relatively complicated, and K ⁺ ions mostly exist in the pores of molecular sieves, which cannot be uniformly doped in the MnO ₂ lattice.

Contents of the invention

Aiming at the above-mentioned problems in the prior art, the present invention provides a potassium-doped _MnO2 catalyst and a preparation method thereof.

In order to achieve the above-mentioned purpose of the invention, the embodiment of the present invention adopts the following technical solutions:

A kind of potassium-doped MnO _The preparation method of catalyst, comprises the steps:

The _MnO2 precursor is added to the KOH solution, reflux reaction, the product is dried and roasted to obtain the potassium-doped _MnO2 catalyst KOH-OMS-2, wherein, Mn ⁴⁺ in the _MnO2 precursor accounts for 88- of the total amount of Mn elements 92%.

With respect to prior art, the preparation method of potassium-doped MnO ₂ catalyst provided by the present invention, MnO ₂ precursor is refluxed in KOH solution, and the Mn ³⁺ ion in MnO ₂ precursor produces disproportionation reaction in alkaline environment, The obtained Mn ²⁺ reduces the content of Mn due to a small amount of dissolution in water, forming Mn vacancies, and the K ⁺ in the system is located near the Mn vacancies, replacing Mn ions, and forming bonds with O ions, so that K ⁺ ions are doped to Between the MnO ₂ lattice, the alkaline environment can make -OH adsorb on the surface of MnO ₂ , and after calcination, the MnO ₂ catalyst KOH-OMS-2 doped with K ⁺ and -OH at the same time is obtained. The method has the advantages of simple process, energy saving and environmental protection, and convenient operation, so that K ⁺ is uniformly doped in the MnO ₂ crystal lattice.

Further, the molar ratio of KOH to the MnO ₂ precursor is 2-8:0.115, providing an alkaline environment, and at the same time providing K ⁺ and -OH to dope the precursor.

Further, the reflux reaction time is 4-24 hours to ensure sufficient reaction, so that sufficient Mn vacancies are formed in the precursor, and K ⁺ ions are doped into the interlattice of MnO ₂ .

Further, the calcination temperature is 400-500°C, and the time is 4-6h. Change the catalyst into a stable structure, improve the structural strength of the catalyst, and ensure the activity and stability of the catalyst.

Further, the preparation method of the MnO ₂ precursor is as follows: adding benzyl alcohol into the potassium permanganate solution, a redox reaction occurs, and after washing and drying, the MnO ₂ precursor is obtained. In the obtained MnO ₂ precursor, Mn mostly exists as Mn ⁴⁺ , and Mn ⁴⁺ /(Mn ³⁺ +Mn ⁴⁺ ) is 88-92%. And with more oxygen vacancies, it has higher catalytic activity.

Further, the molar ratio of benzyl alcohol to potassium permanganate is 0.5-5:1, potassium permanganate is used as an oxidizing agent, benzyl alcohol is used as a reducing agent, and benzyl alcohol is dropped into potassium permanganate to form an excess of oxidizing agent The environment is more conducive to the formation of MnO ₂ , and the MnO ₂ precursor is prepared. The excess benzyl alcohol adheres to the surface of the MnO ₂ precursor and detaches during the roasting process, which increases the specific surface area of MnO ₂ and the oxygen vacancies.

Further, the oxidation-reduction reaction temperature is 10-15° C., and the time is 20-24 hours, so as to ensure the smooth progress of the oxidation-reduction reaction and form the MnO ₂ precursor.

Further, the drying temperature is 100-120° C., and the drying time is 10-12 hours.

The present invention also provides a potassium-doped MnO ₂ catalyst, which is prepared by the above-mentioned preparation method of a potassium-doped MnO ₂ catalyst.

In the catalyst provided by the present invention, because K ⁺ is doped between the MnO ₂ lattices and -OH is adsorbed on the surface of MnO ₂ , it can cause lattice oxygen instability and at the same time cause oxygen coordination unsaturation, increasing the concentration of active oxygen species. quantity, so that the catalyst has higher activity and catalytic ability.

The present invention also provides the application of the above potassium-doped _MnO2 catalyst in the catalytic oxidation of VOCs.

Further, the VOCs are at least one of benzene, toluene or xylene.

Further, the catalytic oxidation temperature is 100-300°C, preferably, the catalytic oxidation temperature is 110-220°C.

Potassium-doped _MnO provided by the invention The application of the catalyst in catalytic oxidation of VOCs, for low-temperature catalytic oxidation of VOCs organic waste gas, T ₁₀₀ during catalytic oxidation of VOCs organic waste gas, T ₅₀ and T ₂₀ (T ₁₀₀ , T ₅₀ and T ₂₀ refer to the temperature when the yield of CO ₂ is 100%, 50% and 20%, respectively) is lower than the corresponding temperature of OMS-2 (prepared by direct calcination of MnO ₂ precursor) without KOH solution treatment. The catalytic oxidation activity of KOH-OMS-2 on VOCs organic waste gas is enhanced, and the low-temperature treatment efficiency is improved.

Description of drawings

Fig. 1 is the catalyst activity test figure of KOH-OMS-2 catalyst and OMS-2 catalyst in the embodiment of the present invention;

Fig. 2 is the XRD spectrogram of KOH-OMS-2 catalyst and OMS-2 catalyst in the embodiment of the present invention;

Fig. 3 is the SEM figure of KOH-OMS-2 catalyst in the embodiment of the present invention;

Fig. 4 is the SEM figure of OMS-2 catalyst;

Fig. 5 is the EDX collection of illustrative plates of KOH-OMS-2 catalyst in the embodiment of the present invention;

Fig. 6 is the EDX collection of illustrative plates of OMS-2 catalyst;

Fig. 7 is the FT-IR spectrum of KOH-OMS-2 catalyst and OMS-2 catalyst in the embodiment of the present invention;

Figure 8, Figure 9 and Figure 10 are the XPS spectra of the KOH-OMS-2 catalyst and the OMS-2 catalyst in the examples of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Example 1

A kind of potassium-doped MnO _The preparation method of catalyst, comprises the steps:

S1: Take 3.16g (0.02mol) of KMnO ₄ completely dissolved in 50mL of distilled water to obtain a KMnO ₄ solution, take 2.1mL (0.02mol) of benzyl alcohol and add it dropwise to the KMnO ₄ solution. Stir and react in a water bath at ℃ for 24 hours, filter with suction, wash with water until neutral, wash with ethanol, then wash with water until neutral, and dry at 110℃ for 12 hours to obtain the MnO ₂ precursor, wherein Mn ⁴⁺ in the MnO ₂ precursor accounts for the Mn element 92% of the total;

S2: Take 33.6g (0.6mol) KOH in a 50mL beaker, dissolve it in distilled water, transfer the KOH solution into a 100mL volumetric flask, dilute to the mark with distilled water, shake well, and prepare a 6M KOH solution. Measure 23mL of the prepared KOH solution into a 100mL round bottom flask, add 1g (11.5mmol) of the above-mentioned _MnO2 precursor, heat to reflux for 12h, filter with suction and wash with water until neutral, dry at 110°C for 12h, then dry at 400°C Calcined for 6h, the potassium-doped MnO ₂ catalyst KOH-OMS-2 was obtained.

Example 2

A kind of potassium-doped MnO _The preparation method of catalyst, comprises the steps:

S1: Take 3.16g (0.02mol) of KMnO ₄ completely dissolved in 50mL of distilled water to obtain a KMnO ₄ solution, take 2.1mL (0.02mol) of benzyl alcohol and add it dropwise to the KMnO ₄ solution. Stir and react in a water bath at ℃ for 24 hours, filter with suction, wash with water until neutral, wash with ethanol, then wash with water until neutral, and dry at 110℃ for 12 hours to obtain the MnO ₂ precursor, wherein Mn ⁴⁺ in the MnO ₂ precursor accounts for the Mn element 92% of the total;

S2: Take 11.2g (0.2mol) KOH in a 50mL beaker, dissolve it in distilled water, transfer the KOH solution into a 100mL volumetric flask, dilute to the mark with distilled water, shake well, and prepare a 2M KOH solution. Measure 23mL of the prepared KOH solution into a 100mL round bottom flask, add 1g (11.5mmol) of the above MnO ₂ precursor, heat to reflux for 12h, filter with suction and wash with water until neutral, dry at 110°C for 12h, then dry at 400°C Calcined for 6h, the potassium-doped MnO ₂ catalyst KOH-OMS-2 was obtained.

Example 3

A kind of potassium-doped MnO _The preparation method of catalyst, comprises the steps:

S1: Take 3.16g (0.02mol) of KMnO ₄ completely dissolved in 50mL of distilled water to obtain a KMnO ₄ solution, take 1.05mL (0.001mol) of benzyl alcohol and add it dropwise to the KMnO ₄ solution. Stir and react in a water bath at ℃ for 20 h, filter with suction, wash with water until neutral, then wash with ethanol, then wash with water until neutral, and dry at 120 °C for 10 h to obtain the MnO ₂ precursor, wherein Mn ⁴⁺ in the MnO ₂ precursor accounts for the Mn element 90% of the total amount;

S2: Take 44.8g (0.8mol) KOH in a 50mL beaker, dissolve it in distilled water, transfer the KOH solution into a 100mL volumetric flask, dilute to the mark with distilled water, shake well, and prepare an 8M KOH solution. Measure 23mL of the prepared KOH solution into a 100mL round-bottomed flask, add 1g (11.5mmol) of the above-mentioned MnO ₂ precursor, heat to reflux for 12h, filter with suction and wash with water until neutral, dry at 120°C for 10h, then dry at 400°C Calcined for 6h, the potassium-doped MnO ₂ catalyst KOH-OMS-2 was obtained.

Example 4

A kind of potassium-doped MnO _The preparation method of catalyst, comprises the steps:

S1: Take 3.16g (0.02mol) of KMnO ₄ and completely dissolve it in 50mL of distilled water to obtain a KMnO ₄ solution, take 4.2mL (0.04mol) of benzyl alcohol and add it dropwise to the KMnO ₄ solution. Stir and react in a water bath at ℃ for 23 hours, filter with suction, wash with water until neutral, then wash with ethanol, then wash with water until neutral, and dry at 110℃ for 12 hours to obtain the MnO ₂ precursor, wherein Mn ⁴⁺ in the MnO ₂ precursor accounts for the Mn element 89% of the total;

S2: Take 33.6g (0.6mol) KOH in a 50mL beaker, dissolve it in distilled water, transfer the KOH solution into a 100mL volumetric flask, dilute to the mark with distilled water, shake well, and prepare a 6M KOH solution. Measure 23mL of the prepared KOH solution into a 100mL round bottom flask, add 1g (11.5mmol) of the above-mentioned MnO ₂ precursor, heat to reflux for 4h, filter with suction and wash with water until neutral, dry at 110°C for 12h, then dry at 400°C Calcined for 6h, the potassium-doped MnO ₂ catalyst KOH-OMS-2 was obtained.

Example 5

A kind of potassium-doped MnO _The preparation method of catalyst, comprises the steps:

S1: Take 3.16g (0.02mol) of KMnO ₄ completely dissolved in 50mL of distilled water to obtain a KMnO ₄ solution, take 10.5mL (0.1mol) of benzyl alcohol and add it dropwise to the KMnO ₄ solution. Stir and react in a water bath at ℃ for 24 hours, filter with suction, wash with water until neutral, wash with ethanol, then wash with water until neutral, and dry at 110℃ for 12 hours to obtain the MnO ₂ precursor, wherein Mn ⁴⁺ in the MnO ₂ precursor accounts for the Mn element 88% of the total;

S2: Take 33.6g (0.6mol) KOH in a 50mL beaker, dissolve it in distilled water, transfer the KOH solution into a 100mL volumetric flask, dilute to the mark with distilled water, shake well, and prepare a 6M KOH solution. Measure 23mL of the prepared KOH solution into a 100mL round-bottomed flask, add 1g (11.5mmol) of the above-mentioned MnO ₂ precursor, heat to reflux for 24h, filter with suction and wash with water until neutral, dry at 110°C for 12h, then dry at 400°C Calcined for 6h, the potassium-doped MnO ₂ catalyst KOH-OMS-2 was obtained.

Example 6

A kind of potassium-doped MnO _The preparation method of catalyst, comprises the steps:

S1: Take 3.16g (0.02mol) of KMnO ₄ completely dissolved in 50mL of distilled water to obtain a KMnO ₄ solution, take 2.1mL (0.02mol) of benzyl alcohol and add it dropwise to the KMnO ₄ solution. Stir and react in a water bath at ℃ for 24 hours, filter with suction, wash with water until neutral, then wash with ethanol, then wash with water until neutral, and dry at 100℃ for 12 hours to obtain the MnO ₂ precursor, wherein Mn ⁴⁺ in the MnO ₂ precursor accounts for the Mn element 92% of the total;

S2: Take 33.6g (0.6mol) KOH in a 50mL beaker, dissolve it in distilled water, transfer the KOH solution into a 100mL volumetric flask, dilute to the mark with distilled water, shake well, and prepare a 6M KOH solution. Measure 23mL of the prepared KOH solution into a 100mL round bottom flask, add 1g (11.5mmol) of the above-mentioned MnO ₂ precursor, heat to reflux for 12h, filter with suction and wash with water until neutral, dry at 100°C for 12h, then dry at 450°C Calcined for 5h to obtain potassium-doped MnO ₂ catalyst KOH-OMS-2.

Example 7

A kind of potassium-doped MnO _The preparation method of catalyst, comprises the steps:

S1: Take 3.16g (0.02mol) of KMnO ₄ completely dissolved in 50mL of distilled water to obtain a KMnO ₄ solution, take 2.1mL (0.02mol) of benzyl alcohol and add it dropwise to the KMnO ₄ solution. Stir and react in a water bath at ℃ for 24 hours, filter with suction, wash with water until neutral, wash with ethanol, then wash with water until neutral, and dry at 110℃ for 11 hours to obtain the MnO ₂ precursor, wherein Mn ⁴⁺ in the MnO ₂ precursor accounts for the Mn element 92% of the total;

S2: Take 33.6g (0.6mol) KOH in a 50mL beaker, dissolve it in distilled water, transfer the KOH solution into a 100mL volumetric flask, dilute to the mark with distilled water, shake well, and prepare a 6M KOH solution. Measure 23mL of the prepared KOH solution into a 100mL round bottom flask, add 1g (11.5mmol) of the above-mentioned MnO ₂ precursor, heat to reflux for 12h, filter with suction and wash with water until neutral, dry at 110°C for 11h, then dry at 500°C Calcined for 4h, the potassium-doped MnO ₂ catalyst KOH-OMS-2 was obtained.

In order to better illustrate the technical solution of the present invention, a further comparison is made below through comparative examples and examples of the present invention.

Comparative example 1

A kind of MnO _The preparation method of catalyst, comprises the steps:

Take 3.16g (0.02mol) of KMnO ₄ and dissolve it completely in 50mL of distilled water to obtain a KMnO ₄ solution. Take 2.1mL (0.02mol) of benzyl alcohol and add it dropwise to the KMnO ₄ solution. Stir in medium temperature for 24 hours, filter with suction, wash with water until neutral, then wash with ethanol, then wash with water until neutral, dry at 110°C for 11h, and calcined at 400°C for 6h to obtain OMS-2 catalyst.

In order to better illustrate the characteristics of the potassium-doped _MnO2 catalyst provided in the examples of the present invention, the potassium-doped _MnO2 catalyst prepared in Example 1 and the OMS-2 catalyst prepared in Comparative Example 1 were evaluated for catalyst activity.

Catalyst activity evaluation: A quartz tube with an inner diameter of 4mm was used as a continuous flow reaction device. First, sieve catalyst particles with a diameter of 0.3-0.45 mm in a 40-60 mesh sieve. Weigh 0.5g of catalyst and 1.5g of quartz sand, mix them evenly, put them into a quartz tube, and then insert into a heating furnace. The flow rate of 40mL/min _N2 load 0.04vol.% o-xylene mixed with 10mL/min _O2 , the flow rate of the gas was controlled by a gas mass flow meter, and the gas-solid catalytic reaction was carried out in a quartz glass tube. Ortho-xylene (o-xylene) enters the analyzer through a capillary column for separation and analysis. CO ₂ is separated through a packed column and converted to CH ₄ through a reformer for analysis. Reaction conditions: 0.04vol.% o-xylene, 20% O ₂ /N ₂ balance, total gas flow rate of 50 mL/min, W/F=0.60 gsmL ^-1 . The results of T ₁₀₀ , T ₅₀ and T ₂₀ (T ₁₀₀ , T ₅₀ and T ₂₀ refer to the temperatures when the CO ₂ yields are 100%, 50% and 20% respectively) are shown in Table 1 and FIG. 1 .

Table 1

Catalyst activity T₁₀₀/℃ T₅₀/℃ T₂₀/℃ Example 1 170 144 130 Comparative example 1 180 162 153

From the above table and Fig. 1 data as can be known, T ₁₀₀ when the KOH-OMS-2 catalyst catalytic oxidation 400ppm o-xylene provided by the present invention, T ₅₀ and T ₂₀ than the corresponding temperature of the OMS-2 catalyst that KOH solution is not processed respectively Decreased by 10°C, 18°C and 23°C. It shows that the catalytic combustion activity of KOH-OMS-2 catalyst to pollutants is enhanced, and the low temperature treatment efficiency is obviously improved. The KOH-OMS-2 catalyst provided in other embodiments of the present invention has a comparable effect to that of embodiment 1.

In order to better illustrate the potassium-doped _MnO2 catalyst characteristic that the embodiment of the present invention provides, the following KOH-OMS-2 catalyst prepared by Example 1 and the OMS-2 catalyst prepared by Comparative Example 1 are carried out XRD, SEM, EDX, FT-IR and XPS correlation analysis.

The XRD spectrogram of KOH-OMS-2 catalyzer and OMS-2 catalyzer is as shown in Figure 2, can obtain by XRD, the embodiment of the present invention successfully synthesized MnO ₂ precursor OMS-2 (manganese oxide octahedral molecular sieve crystal form) , and the K ⁺ in the KOH-OMS-2 catalyst is highly dispersed among the OMS-2, so that K ⁺ is uniformly doped in the MnO ₂ lattice. The scanning SEM images of the OMS-2 catalyst and the KOH-OMS-2 catalyst are shown in Figure 3 and Figure 4, respectively. The SEM results show that the OMS-2 particles become smaller after the KOH reflux reaction. The energy dispersive X-ray spectrometer (EDX) patterns of OMS-2 catalyst and KOH-OMS-2 catalyst are shown in Fig. 5 and Fig. 6 respectively, and EDX shows, compared with OMS-2, the content of Mn in KOH-OMS-2 The content of Mn decreased by 3.5%, while the content of K increased by 3.5%, indicating that K replaced Mn and was doped in the MnO ₂ lattice. The Fourier (FT-IR) infrared spectra of OMS-2 catalyst and KOH-OMS-2 catalyst are shown in Figure 7, and the spectral peaks at 715cm ^-1 , 574cm ^-1 , 526cm ^-1 and 471cm ^-1 in FT-IR represent The presence of [MnO ₆ ] structural units in OMS-2, 3400 cm ^-1 and 1600 cm ^-1 confirmed the presence of OH functional groups, indicating that -OH was adsorbed on the surface of MnO ₂ .

The XPS spectra of OMS-2 catalyst and KOH-OMS-2 catalyst are shown in Figure 8, 9 and 10, wherein, Figure 8 is the Mn2p result of OMS-2 catalyst and KOH-OMS-2 catalyst, in KOH-OMS-2 The content of Mn ⁴⁺ increased slightly, indicating that the disproportionation reaction of Mn ³⁺ in the MnO ₂ precursor produced Mn ⁴⁺ and Mn ²⁺ . Mn ²⁺ was dissolved in water while Mn ⁴⁺ existed in the system, so the content increased. Figure 9 is the result of K2p, indicating that K is doped in OMS-2 in the form of ions; Figure 10 is the result of O1s, indicating that after KOH reflux, the binding energy of O is high, and the electron density around it becomes smaller. In addition, KOH The surface hydroxyl OH content in -OMS-2 is increased compared with OMS-2, indicating that the catalyst of the present invention is a KOH-OMS-2 catalyst in which K ⁺ and -OH are simultaneously doped with MnO ₂ .

Can obtain from above data, the preparation method of potassium-doped _MnO2 catalyst provided by the present invention, _MnO2 precursor is refluxed in KOH solution, obtain the KOH-OMS-2 catalyst that K ⁺ and -OH are doped at the same time, K ⁺ Evenly doped in the MnO ₂ lattice, -OH is adsorbed on the surface of MnO ₂ , which enhances the catalytic oxidation activity of the catalyst for VOCs organic waste gas, and improves the low-temperature treatment efficiency.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements or improvements made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (10)

1. a kind of potassium adulterates MnO₂The preparation method of catalyst, characterized by the following steps:

By MnO₂Presoma is added in KOH solution, back flow reaction, and product obtains potassium doping MnO through dry and roasting₂Catalyst, Wherein, MnO₂Mn in presoma⁴⁺Account for the 88-92% of Mn element total amount.

2. potassium as described in claim 1 adulterates MnO₂The preparation method of catalyst, it is characterised in that: the KOH and MnO₂Forerunner Body molar ratio is 2-8:0.115.

3. potassium as described in claim 1 adulterates MnO₂The preparation method of catalyst, it is characterised in that: the reflux time For 4-24h.

4. potassium as described in claim 1 adulterates MnO₂The preparation method of catalyst, it is characterised in that: the maturing temperature is 400-500 DEG C, time 4-6h.

5. potassium as described in claim 1 adulterates MnO₂The preparation method of catalyst, it is characterised in that: the MnO₂Presoma The preparation method comprises the following steps: benzyl alcohol is added in liquor potassic permanganate, redox reaction occurs and is made after washed, dry MnO₂Presoma.

6. potassium as claimed in claim 5 adulterates MnO₂The preparation method of catalyst, it is characterised in that: the benzyl alcohol and Gao Meng The molar ratio of sour potassium is 0.5-5:1；The redox reaction temperature is 10-15 DEG C, time 20-24h.

7. potassium as claimed in claim 1 or 5 adulterates MnO₂The preparation method of catalyst, it is characterised in that: the drying temperature is 100-120 DEG C, time 10-12h.

8. a kind of potassium adulterates MnO₂Catalyst, it is characterised in that: be made by the described in any item preparation methods of claim 1 to 7.

9. potassium according to any one of claims 8 adulterates MnO₂Application of the catalyst in catalysis oxidation VOCs.

10. potassium as claimed in claim 9 adulterates MnO₂Application of the catalyst in catalysis oxidation VOC, it is characterised in that: described VOCs is at least one of benzene, toluene or dimethylbenzene.