CN115990474A - A kind of VOCs catalyst, preparation method and application - Google Patents

Abstract

Provided are a perovskite catalyst and a preparation method thereof. The perovskite catalyst includes a perovskite active component with a general formula of A _x B _1-x Mny _{Ti 1-y} O ₃ and a sepiolite component. The catalyst preparation method comprises: treating sepiolite with inorganic acid modification solution; mixing sepiolite and citric acid; adding soluble metal salts of A and B; adding Mn/ _TiO2 sol; adding ethylene glycol aqueous solution, and heating and evaporating A gel is obtained; the catalyst is obtained by drying the gel, heating it, burning it in anaerobic manner, molding and calcining the combustion ash. The preparation process of the catalyst is simple, easy to operate, suitable for large-scale industrial application, and overcomes the disadvantage of poor dispersion of the perovskite powder prepared by the self-combustion method, improves the high-temperature sintering resistance of the catalyst, and has excellent thermal stability.

Description

A kind of VOCs catalyst, preparation method and application

technical field

The invention belongs to the technical field of energy utilization and environmental protection, and in particular relates to a perovskite-type VOCs catalyst, a preparation method and an application.

Background technique

Volatile organic compounds (VOCs) refer to the general term for organic compounds with a saturated vapor pressure greater than 70 Pa at normal temperature and a boiling point below 260 °C at normal pressure. They can participate in the formation of ozone and secondary aerosols in the atmospheric environment, and are serious pollution Chemical material. At present, the pollution problem of VOCs is becoming more and more serious, and gradually attracts the attention of the environmental protection department.

At present, the methods of treating volatile organic waste gas include adsorption and absorption method, biodegradation treatment method, UV ultraviolet photolysis-plasma method, direct combustion and catalytic combustion method, etc. Among them, catalytic combustion treatment of VOCs has high purification rate and low ignition temperature. , Energy saving, simple process, no secondary pollution and other characteristics are widely used.

The research on VOCs catalytic combustion catalysts mainly focuses on noble metal catalysts (Pt, Pd and Au) and non-noble metal oxide catalysts. Among them, Pd catalyst is the most mature and widely used combustion catalyst in industry, but it is expensive. Non-precious metal catalysts have poor low-temperature activity, but their resources are abundant and cheap, and they have the prospect of large-scale application.

Among non-noble metal catalytic combustion catalysts, perovskite-type composite metal oxide (structure general formula ABO ₃ ) catalyst is one of the most promising catalytic combustion catalysts.

CN105289602 A discloses a cerium-zirconium composite oxide-supported perovskite catalyst with anti-sulfur properties, that is, the perovskite is first loaded on the Ce _1-y Zry _{O 2} composite oxide, and then the noble metal additive is loaded on it. The catalyst has high catalyst reactivity in the process of catalytic combustion of VOCs, and has strong resistance to sulfur poisoning.

CN109999795 A discloses an attapulgite clay-supported LaMnO ₃ catalyst (LaMnO ₃ /ATP for short) for degrading volatile organic pollutants.

CN1015283443 A discloses a method for optimizing the catalytic activity of perovskite-based catalysts. The fully synthesized perovskite structure is subjected to high-energy ball milling to obtain a larger specific surface area, thereby achieving the purpose of improving catalyst activity. However, the method of improving catalytic activity only by increasing the specific surface area has certain limitations.

Perovskite-type metal oxide catalysts have good stability, but there are still problems such as low specific surface area and easy sintering at high temperatures, which limit the application of perovskite-type catalysts.

Therefore, there is an urgent need for a new VOCs catalyst and its preparation method to solve the above technical problems.

Contents of the invention

The object of the present invention is to provide a high specific surface area perovskite catalyst and a preparation method thereof. The catalyst has excellent thermal stability when applied to catalytic combustion of VOCs, and is low in cost and simple in preparation.

In order to overcome the deficiencies in the prior art, the present invention provides a high specific surface area perovskite catalyst with excellent thermal stability, based on the weight percentage of the catalyst, the catalyst composition includes a perovskite active component 40 ~50%, the rest is sepiolite;

Wherein, the general formula of the perovskite active component is A _x B _{1-x Mny} Ti _1-y O ₃ , where x=0.1-0.4, y=0.5-0.8, where A is La, Ce At least one of, B is at least one of Mg, Ca.

The pore volume of the catalyst is 0.45mL/g-0.55mL/g, 90% of the pore diameter is 25nm-45nm, and the specific surface area is 100m ² /g-130m ² /g.

The appearance of the catalyst can be strip-shaped, clover-shaped, four-leaf clover-shaped or spherical, etc.

The bulk density of the catalyst is 0.75-0.90Kg/L, and the lateral pressure of the catalyst is 100-120N/cm.

The present invention also provides the preparation method of above-mentioned perovskite catalyst, comprising:

(1) Prepare the inorganic acid modification solution; then add sepiolite and the inorganic acid modification solution into the reactor at a solid-to-liquid weight ratio of 1:15-30 and heat to 50-100°C for a period of time, After the stirring is completed, filter and wash with water until neutral, dry and roast to obtain modified sepiolite;

(2) Get a certain amount of modified sepiolite and citric acid obtained in step (1) and pour into water, mix uniformly, and obtain the first mixture;

(3) According to the molar ratio of metal elements required by the perovskite active component, prepare aqueous solutions of soluble metal salts of A and B respectively, and add them dropwise to the first mixture obtained in step (2) respectively, and stir Uniformly, the second mixture is obtained;

(4) preparing Mn/ _TiO sol, then adding the prepared Mn/ _TiO sol dropwise to the second mixture obtained in step (3), stirring evenly to obtain the third mixture;

(5) Add a certain amount of ethylene glycol aqueous solution to the third mixture obtained in step (4) and stir evenly; heat up to a certain temperature to evaporate water, so that it gradually becomes a gel;

(6) Dry the gel obtained in step (5) at 80-150°C, then move it to an electric furnace and heat it to a constant temperature after spontaneous combustion; crush the burning ashes and add binders and extrusion aids to extrude The catalyst is obtained after being molded, dried and calcined.

Wherein, in the step (1), the water is distilled water, and the stirring time is 8-12 hours.

Wherein, in the step (1), the sepiolite is α-type sepiolite, the color is white or light gray, and light red, light yellow or brown are avoided. Preferably, the sepiolite is pure white sepiolite or off-white sepiolite, and the mass percent composition of the pure white sepiolite is: SiO ₂ 66%-68%, MgO 30%-32%, Fe _x O _y <0.2%, the balance is Al ₂ O ₃ , CaO; the mass percent composition of the off-white sepiolite is: SiO ₂ 65%-67%, MgO 30%-32%, F _x O _y <1.0 %, the balance is Al ₂ O ₃ , CaO.

Wherein, in the step (1), the calcination temperature is 350-400° C., and the calcination time is 4-8 hours.

Wherein, in the step (1), the inorganic acid is one of nitric acid, hydrochloric acid or sulfuric acid, preferably nitric acid; the concentration of the inorganic acid is 0.2-0.4 mol/L.

Wherein, in the step (2), the water is deionized water.

Wherein, in the step (3), the soluble metal salt of A is at least one of lanthanum nitrate and cerium nitrate; the soluble metal salt of B is at least one of magnesium nitrate and calcium nitrate.

Wherein, in the step (2), the ratio of the moles of the citric acid to the sum of the moles of metal ions in the steps (3) and (4) is 1:2-4.

Wherein, in described step (4), Mn/TiO The preparation method of _sol comprises:

Take a certain amount of tetra-n-butyl titanate, absolute ethanol and polyethylene glycol (PEG600) and stir vigorously in the reaction kettle, add glacial acetic acid dropwise to the mixture to control its pH value to 4-5;

Then weigh a certain amount of manganese acetate by the required metal element molar ratio of the perovskite active component, add deionized water to dissolve and obtain Mn(Ac) ₂ solution;

Slowly add the Mn(Ac) ₂ solution into the reaction kettle, and continue stirring for a period of time after completion to obtain the Mn/TiO ₂ sol.

Wherein, in the step (5), the mass concentration of the aqueous ethylene glycol solution is greater than 60%, and the added amount of the aqueous ethylene glycol solution is 10-15% of the total mass of the perovskite-type active component ABO ₃ . Ethylene glycol acts as a combustion aid during the preparation process.

Wherein, in the step (6), drying is carried out at 80-150°C.

Wherein, in the step (6), the temperature of the constant temperature is 200-250°C, and after the material is ignited, air with an oxygen content of 15-18% (v/v) needs to be introduced to control the burning speed.

Wherein, in the step (6), the binder is one or more of water glass, citric acid, oxalic acid and nitric acid, and the amount of the binder is 1 to 6% of the burning ash (m/m); Preferably, the binder is at least one of water glass and citric acid, and its addition is 2-4% (m/m) of the burning ash.

Wherein, in the step (6), the extrusion aid is Tianqing powder and starch, and the addition amount is 1 to 6% (m/m) of the burning ash; preferably, the extrusion aid is Sesame powder, the addition amount is 3～4% (m/m) of burning ash.

Wherein, in the step (6), the calcination temperature is 500-1000°C, and the calcination time is 4-8h; preferably, the calcination temperature is 700-780°C, and the calcination time is 5-6h. Calcination temperature affects the formation of perovskite-type active components.

The invention also provides the application of the perovskite catalyst in catalytic combustion treatment of volatile organic compounds.

The present invention has the following beneficial technical effects:

(1) The present invention uses acid-modified sepiolite as a carrier, adopts the beating method to load the active component sol on the modified sepiolite, and the active component gel anaerobic self-combustion to generate a perovskite structure after roasting, so that the active The components are uniformly dispersed on the sepiolite carrier, and a perovskite-type VOCs catalytic combustion catalyst is prepared.

(2) Sepiolite (Mg ₈ [Si ₂ O ₃₀ ](OH) ₄ 12H ₂ O) is a magnesium-rich silicate clay mineral, which belongs to the chain layer of S monoclinic or orthorhombic Hydrous magnesium aluminum silicate or magnesium silicate mineral has a huge specific surface area and can adsorb various reactants and active components of catalysts. Through acid modification, the magnesium ions in the sepiolite framework are partially replaced by H ⁺ , so that the magnesium-oxygen octahedral sheets sandwiched by the silicon-oxygen tetrahedral sheets are partially deconstructed, and the internal channels can be connected and expanded, which significantly increases the sepiolite. The specific surface area of the carrier. The pore size of sepiolite matches the molecular size of the reactant and the size of the catalyst component. The sepiolite carrier can exhibit good activity and high heat resistance, thus obtaining a catalyst carrier with a high specific surface area, which is conducive to the adsorption of VOCs during the reaction process .

(3) During the preparation process, the gel solid naturally makes the material fluffy, which is conducive to the dispersion of active components, the exposure of active sites increases, and the catalytic activity increases significantly.

(4) The method of the present invention can not only load a large amount of active components, but also be easy to regulate the active material composition of the catalyst, and a suitable composition improves the high-temperature sintering resistance of the active components, so that the catalyst has excellent thermal stability.

(5) The method of the present invention can increase the dispersion of the catalyst and improve its thermal stability by introducing a structural aid with thermal stability and loading the perovskite metal oxide catalyst on a suitable high specific surface area carrier. sex.

(6) The method of the present invention has a simple preparation process, is easy to operate, and is suitable for large-scale industrial application.

(7) The prepared catalyst perovskite component of the method of the present invention has high purity and small particle size, and overcomes the disadvantage of poor dispersibility of the perovskite powder prepared by the self-combustion method, and improves the high-temperature sintering resistance of the catalyst, Has excellent thermal stability.

Detailed ways

In view of the problems of low specific surface area and easy sintering at high temperature in existing titanite-type catalytic combustion catalysts, the present invention proposes a perovskite-type catalytic combustion catalyst with high specific surface area, its preparation method and application.

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments. 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

1) Prepare a 0.2mol/L nitric acid solution, add 122.4g of sepiolite powder according to the solid-liquid weight ratio of 1:15, stir, wash, and dry at 400°C for 4 hours to obtain modified sepiolite;

2) Add the modified sepiolite and 134.4g of citric acid into 500mL of deionized water, mix and stir evenly.

3) Prepare 200 mL of 0.5 mol/L lanthanum nitrate solution and 900 mL of 1.0 mol/L magnesium nitrate solution respectively, and stir the solutions into the mixture in step 2).

4) Prepare the Mn/TiO ₂ sol according to the molar ratio Mn:Ti=1:1, take 416g of the sol and slowly add it to the mixture in step 3), and stir evenly.

5) Add 25 mL of ethylene glycol solution to the mixture in step 4) and stir evenly, then heat to evaporate water until a gel is formed.

6) Dry the gel obtained in step 5) at 150°C, then move it to an electric furnace and heat it to 250°C to trigger spontaneous combustion, then keep the temperature constant, and pass in air with an oxygen content of 18% (v/v) to control the burning speed. Combustion ashes were pulverized and extruded by adding 5g of citric acid and 7.5g of scallop powder, dried in the air, and calcined at 750°C for 5 hours to obtain the catalyst.

The perovskite active component content in the catalyst prepared by the above steps is 50%, and the active component composition is La _0.1 Mg _0.9 Mn _0.5 Ti _0.5 O ₃ , denoted as cat-1.

Embodiment 2-8

According to the preparation method of Example 1, according to the parameter range in the specification, the distribution ratio of each component was adjusted, and the prepared catalysts were respectively recorded as cat-2 to cat-8, as shown in Table 1.

Comparative Example 1 - Introducing Ti in the form of introducing metatitanic acid in step (2) instead of introducing Ti in the form of introducing Mn/TiO2 sol in step (4) as described in Example 1

1) Prepare a 0.2 mol/L nitric acid solution, add 122.4 g of sepiolite powder according to the solid-to-liquid weight ratio of 1:15, stir, wash, dry, and roast at 400°C for 4 hours to obtain modified sepiolite.

2) Add the modified sepiolite, 134.4g of citric acid, and 48.9g of metatitanic acid into 500mL of deionized water, mix and stir evenly.

3) Prepare 200 mL of 0.5 mol/L lanthanum nitrate solution and 900 mL of 1.0 mol/L magnesium nitrate solution respectively, and stir the solutions into the mixture in step 2).

4) Prepare 500 mL of 1.0 mol/L manganese nitrate solution, slowly add it to the mixture in step 3), and stir evenly.

5) Add 25 mL of ethylene glycol solution to the mixture in step 4) and stir evenly, then heat to evaporate water until a gel is formed.

6) Dry the gel obtained in step 5) at 150°C, then move it to an electric furnace and heat it to 250°C to trigger spontaneous combustion, then keep the temperature constant, and pass in air with an oxygen content of 15% (v/v) to control the burning speed. Combustion ashes were pulverized and extruded by adding 5g of citric acid and 7.5g of scallop powder, dried in the air, and calcined at 750°C for 5 hours to obtain the catalyst.

The perovskite active component content in the catalyst prepared by the above steps is 50%, and the active component composition is La _0.1 Mg _0.9 Mn _0.5 Ti _0.5 O ₃ , denoted as cat-9.

Comparative example 2 - modified sepiolite without citric acid treatment

1) Prepare a 0.2mol/L nitric acid solution, add 122.4g of sepiolite powder according to the solid-to-liquid weight ratio of 1:15, stir, wash, dry, and roast at 400°C for 4 hours to obtain modified sepiolite.

2) Prepare 200 mL of 0.5 mol/L lanthanum nitrate solution and 900 mL of 1.0 mol/L magnesium nitrate solution respectively, and mix them to obtain a mixed solution.

3) Prepare the Mn/TiO ₂ sol according to the molar ratio Mn:Ti=1:1, take 416g of the sol and slowly add it to the mixture in step 2), and stir evenly.

4) Add 25 mL of ethylene glycol solution to the mixture in step 3) and stir evenly, then heat to evaporate water until a gel is formed.

5) Dry the gel obtained in step 4) at 150°C, then move it to an electric furnace and heat it to 250°C to trigger spontaneous combustion, then keep the temperature constant, and pass in air with an oxygen content of 16% (v/v) to control the burning speed. Combustion ashes were pulverized and then added 5g of citric acid, 7.5g of turmeric powder, and 122.4g of modified sepiolite from step 1), mixed evenly, extruded and dried, and calcined at 750°C for 5 hours to obtain a catalyst.

The perovskite active component content in the catalyst prepared by the above steps is 50%, and the active component composition is La _0.1 Mg _0.9 Mn _0.5 Ti _0.5 O ₃ , which is recorded as comparative cat-10.

Comparative example 3 - without adding ethylene glycol solution and evaporating to form a gel, without anaerobic spontaneous combustion

1) Prepare a 0.2 mol/L nitric acid solution, add 122.4 g of sepiolite powder according to the solid-to-liquid weight ratio of 1:15, stir, wash, dry, and roast at 400°C for 4 hours to obtain modified sepiolite.

2) Add the modified sepiolite and 134.4g of citric acid into 500mL of deionized water, mix and stir evenly.

3) Prepare 200 mL of 0.5 mol/L lanthanum nitrate solution and 900 mL of 1.0 mol/L magnesium nitrate solution respectively, and stir the solutions into the mixture in step 2).

4) Prepare the Mn/TiO ₂ sol according to the molar ratio Mn:Ti=1:1, take 416g of the sol and slowly add it to the mixture in step 3), and stir evenly.

5) The mixture obtained in step 4) was dried at 150°C. After drying, the material was pulverized and extruded by adding 5g of citric acid and 7.5g of turnip powder, dried in the air, and roasted at 750°C for 5 hours to obtain a catalyst.

The perovskite active component content in the catalyst prepared by the above steps is 50%, and the active component composition is La _0.1 Mg _0.9 Mn _0.5 Ti _0.5 O ₃ , which is recorded as comparative example cat-11.

Comparative example 4 - no spontaneous combustion under oxygen-deficient conditions

1) Prepare a 0.2 mol/L nitric acid solution, add 122.4 g of sepiolite powder according to the solid-to-liquid weight ratio of 1:15, stir, wash, dry, and roast at 400°C for 4 hours to obtain modified sepiolite.

2) Add the modified sepiolite and 134.4g of citric acid into 500mL of deionized water, mix and stir evenly.

3) Prepare 200 mL of 0.5 mol/L lanthanum nitrate solution and 900 mL of 1.0 mol/L magnesium nitrate solution respectively, and stir the solutions into the mixture in step 2).

4) Prepare the Mn/TiO ₂ sol according to the molar ratio Mn:Ti=1:1, take 416g of the sol and slowly add it to the mixture in step 3), and stir evenly.

5) Add 25 mL of ethylene glycol solution to the mixture in step 4) and stir evenly, then heat to evaporate water until a gel is formed.

6) Dry the gel obtained in step 5) at 150°C, then move it to an electric furnace and heat it to 250°C to cause spontaneous combustion. Combustion ashes were pulverized and extruded by adding 5g of citric acid and 7.5g of scallop powder, dried in the air, and calcined at 750°C for 5 hours to obtain the catalyst.

The perovskite active component content in the catalyst prepared by the above steps is 50%, and the active component composition is La _0.1 Mg _0.9 Mn _0.5 Ti _0.5 O ₃ , which is recorded as comparative cat-12.

The catalysts prepared in Comparative Examples 1-4 are listed in Table 1.

The catalyst prepared by the embodiment and comparative example of table 1

composition serial number Example 1 <![CDATA[La_0.1Mg_0.9Mn_0.5Ti_0.5O₃ ]]> cat-1 Example 2 <![CDATA[La_0.4Mg_0.6Mn_0.5Ti_0.5O₃ ]]> cat-2 Example 3 <![CDATA[La_0.4Mg_0.6Mn_0.8Ti_0.2O₃ ]]> cat-3 Example 4 <![CDATA[La_0.1Mg_0.9Mn_0.8Ti_0.2O₃ ]]> cat-4 Example 5 <![CDATA[Ce_0.4Ca_0.6Mn_0.5Ti_0.5O₃ ]]> cat-5 Example 6 <![CDATA[Ce_0.1Ca_0.9Mn_0.5Ti_0.5O₃ ]]> cat-6 Example 7 <![CDATA[Ce_0.4Ca_0.6Mn_0.8Ti_0.2O₃ ]]> cat-7 Example 8 <![CDATA[Ce_0.1Ca_0.9Mn_0.8Ti_0.2O₃ ]]> cat-8 Comparative example 1 <![CDATA[La_0.1Mg_0.9Mn_0.5Ti_0.5O₃ ]]> cat-9 Comparative example 2 <![CDATA[La_0.1Mg_0.9Mn_0.5Ti_0.5O₃ ]]> cat-10 Comparative example 3 <![CDATA[La_0.1Mg_0.9Mn_0.5Ti_0.5O₃ ]]> cat-11 Comparative example 4 <![CDATA[La_0.1Mg_0.9Mn_0.5Ti_0.5O₃ ]]> cat-12

Performance Testing:

The perovskite-type catalysts prepared in Examples 1-8 and Comparative Examples 1-4 were tested for their activity, and the tests were carried out in a fixed-bed reactor. The whole device is composed of a gas generation system and a catalytic combustion system. The raw gas concentration is controlled by adjusting the air flow and raw gas flow. From 200 to 400°C, the concentration of the inlet and outlet is detected every 10°C, and the GC-14C gas chromatograph (FID, double column) is used for online analysis and detection.

The specific activity evaluation conditions are:

Catalyst particle size: 40-60 mesh;

Catalyst loading: 10mL;

Raw material gas composition: toluene 4000mg/m ³ , the rest is air;

Airspeed: 25000h ^-1

The specific catalyst stability evaluation conditions are:

Catalyst particle size: 40-60 mesh;

Raw material gas composition: toluene 4000mg/m ³ , the rest is air;

Airspeed: 25000h ^-1 ;

Evaluation temperature 400°C

The catalyst evaluation data are listed in Table 2 (T ₉₀ and T ₉₉ in the table are the reaction temperatures when the conversion rate reaches 90% and 99% respectively, and the conversion rate is 400°C data).

Table 2 Catalyst activity evaluation data

According to the data in Table 2, it can be seen that the catalyst of the present invention has a good conversion rate to VOCs.

The catalyzer cat-1 of embodiment 1 and the catalyzer cat-9, cat-10, cat-11, cat-12 of comparative example 1-4 adopt stability evaluation condition to run 200h, test catalyst activity is stable, every 50h sampling analysis, Evaluation data are included in Table 3.

Table 3 Catalyst Activity Stability Evaluation Data

It can be seen from Table 3 that although the catalyst cat-1 has the same active components and the same content as the comparative catalysts cat-9, cat-10, cat-11, and cat-12, its activity is stable due to the difference in the preparation process The difference in activity is relatively large, and the catalyst prepared by the process of the present invention has better activity stability.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. A preparation method of perovskite catalyst,

the perovskite catalyst comprises 40-50% of perovskite active component and the balance of sepiolite component based on the weight percentage of the catalyst;

wherein the perovskite type active component has a general formula of A _x B _1-x Mn _y Ti _1-y O ₃ Wherein x=0.1-0.4, y=0.5-0.8, wherein a is at least one of La and Ce, and B is at least one of Mg and Ca;

the preparation method of the perovskite catalyst comprises the following steps:

(1) Preparing an inorganic acid modified solution; then adding sepiolite and the inorganic acid modified solution into a reactor according to the solid-liquid weight ratio of 1:15-30, heating to 50-100 ℃, stirring for a period of time, filtering with water, washing to be neutral after stirring is completed, and drying and roasting to obtain modified sepiolite;

(2) Pouring a certain amount of the modified sepiolite obtained in the step (1) and citric acid into water, and uniformly mixing to obtain a first mixture;

(3) Preparing water solutions of soluble metal salts of A and B respectively according to the molar ratio of metal elements required by perovskite type active components, dripping the water solutions into the first mixture obtained in the step (2) respectively, and uniformly stirring to obtain a second mixture;

(4) Preparation of Mn/TiO ₂ Sol and then preparing Mn/TiO ₂ Dropwise adding the sol into the second mixture obtained in the step (3), and uniformly stirring to obtain a third mixture;

(5) Adding a certain amount of glycol aqueous solution into the third mixture obtained in the step (4) and stirring uniformly; heating to a certain temperature to evaporate water so as to gradually change the water into gel;

(6) Drying the gel obtained in the step (5), and heating the gel to a constant temperature after spontaneous combustion is initiated; wherein, air with oxygen content of 15-18% (v/v) is introduced after ignition; and then crushing the combustion ash, adding a binder and an extrusion aid, extruding and forming, airing, and roasting to obtain the catalyst.

2. The method for preparing a perovskite-type catalyst according to claim 1, wherein in the step (1), the sepiolite is selected from alpha-sepiolite.

3. The method for producing a perovskite-type catalyst according to claim 1, wherein in the step (1), the inorganic acid is one of nitric acid, hydrochloric acid or sulfuric acid.

4. The method for preparing a perovskite catalyst according to claim 1, wherein in the step (3), the soluble metal salt of a is at least one of lanthanum nitrate and cerium nitrate; the soluble metal salt of B is at least one of magnesium nitrate and calcium nitrate.

5. The method for producing a perovskite-type catalyst according to claim 1, wherein the ratio of the number of moles of citric acid in the step (2) to the sum of the number of moles of metal ions in the step (3) and the step (4) is 1:2 to 4.

6. The method for producing a perovskite catalyst according to claim 1, wherein in the step (6), the constant temperature is 200 to 250 ℃.

7. The method for producing a perovskite catalyst according to claim 1, wherein in the step (6), the calcination temperature is 500 to 1000 ℃ and the calcination time is 4 to 8 hours.

8. A perovskite catalyst prepared by the method of preparing a perovskite catalyst as claimed in any one of claims 1 to 7.

9. The perovskite catalyst of claim 8, wherein the catalyst has a pore volume of 0.45mL/g to 0.55mL/g and a specific surface area of 100m ² /g-130m ² /g。

10. Use of a perovskite-type catalyst as claimed in claim 8 or 9 for the catalytic combustion treatment of volatile organic compounds.