A catalyst for degrading VOCs and its preparation method and application

Abstract

The present invention discloses a catalyst for degrading VOCs, a preparation method and an application thereof, and belongs to the technical field of industrial VOCs catalyst preparation. The catalyst of the present invention includes tin oxide, metal additive oxide and a carrier, wherein the metal additive includes one or more of Nb, Ta, Mn, Co, Fe, Ni, Pt, Ce, Sm, the molar ratio of the tin element to the metal additive element is 1-100:1, and the mass ratio of the tin oxide to the carrier is 1-30:100. The preparation method is: a tin source precursor and a metal additive precursor are prepared into a solution according to a certain ratio, after being completely dissolved, a carrier is added, and the solution is dried after being stirred at 0-60°C for a certain period of time, and then roasted at a certain temperature. The catalyst preparation process of the present invention is simple, the reaction conditions are mild, the catalytic activity is stable and efficient, and it can be recycled and reused.

Description

Technical Field

[0001] The invention relates to a catalyst for degrading VOCs and a preparation method and application thereof, belonging to the technical field of industrial VOCs catalyst preparation. Background Art

[0002] Photocatalyst technology has shown excellent performance in removing organic pollutants from the environment. Under certain conditions, photocatalysts can directly degrade pollutants into mild carbon dioxide and water, thereby reducing pollution and harm to the environment. Currently, titanium dioxide is the most studied photocatalyst, so the development of other photocatalysts with excellent performance is very attractive for environmental governance.

[0003] Tin dioxide is an important wide bandgap semiconductor material. Due to its unique optical, electrical and chemical properties, it is widely used in the field of photocatalysis. Tin dioxide is not only efficient, low-cost, safe and non-toxic in purifying organic pollutants, but also a greener and gentler process. Summary of the invention

[0004] The object of the present invention is to provide a catalyst for degrading volatile organic compounds (VOCs) and a preparation method thereof.

[0005] To achieve the above-mentioned purpose, the present invention first provides a catalyst for degrading VOCs, wherein the catalyst comprises tin oxide, a metal additive oxide and a carrier, wherein the metal additive comprises one or more of Nb, Ta, Mn, Co, Fe, Ni, Pt, Ce, and Sm, the molar ratio of the tin element to the metal additive element is 1-100:1, and the mass ratio of the tin oxide to the carrier is 1-30:100.

[0006] In one embodiment of the present invention, the carrier is one or more of γ-Al2O3, ZSM-5, activated carbon, silicon dioxide, etc.

[0007] The present invention also provides a method for preparing the above-mentioned catalyst for degrading VOCs, which comprises: preparing a tin source precursor and a metal auxiliary agent precursor into a solution in a certain proportion, adding a carrier after they are completely dissolved, stirring for a certain period of time, drying, and then calcining at a certain temperature.

[0008] In one embodiment of the present invention, the tin source precursor includes any one or more of tin chloride, stannous chloride, stannous oxalate, dibutyltin, stannous octoate, dimethyltin, tetraphenyltin, dioctyltin and the like.

[0009] In one embodiment of the present invention, the metal additive precursor is a soluble compound of the metal additive, such as niobium ethoxide, niobium oxalate, niobium chloride; tantalum ethoxide, tantalum chloride; manganese nitrate, manganese carbonate; cobalt carbonate, cobalt nitrate; ferric nitrate, ferric chloride; nickel nitrate, nickel sulfate, nickel sulfonate; platinum dichloride, platinum nitrate; cerium sulfate, cerium nitrate, cerium chloride, cerium carbonate, cerium oxalate, cerium acetate; samarium chloride, samarium nitrate, samarium sulfate, etc.

[0010] In one embodiment of the present invention, after the precursor solution is mixed with the carrier, the stirring time is 2-24 hours and the stirring temperature is 0-60°C.

[0011] In one embodiment of the present invention, the calcination temperature is 300-800°C.

[0012] In one embodiment of the present invention, the calcination process takes 3-8 hours.

[0013] In one embodiment of the present invention, the calcination is performed in air or an inert atmosphere.

[0014] The present invention also provides a method for degrading VOCs, wherein the method utilizes the above catalyst or the catalyst prepared by the above method to perform photocatalysis.

[0015] In one embodiment of the present invention, the VOCs are Volatile Organic Compounds, including but not limited to toluene, xylene, trichloroethane, formaldehyde, and the like.

[0016] The present invention also provides application of the catalyst or the preparation method in the environmental field.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] (1) The preparation method of the catalyst of the present invention is simple, low-cost, and has good industrial application prospects.

[0019] (2) The catalyst prepared by the present invention has a wide operating temperature range, high activity and strong anti-poisoning performance.

[0020] (3) The catalyst prepared by the present invention has good stability and long service life. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0022] Example 1

[0023] Weigh 1.5 g of stannous chloride and 0.05 g of cerium nitrate hexahydrate, add 10 mL of water, stir at room temperature, and after dissolving, add 10 g of ZSM-5, stir at room temperature for 12 hours, and dry at 80°C for 6 hours. Then place in a muffle furnace and bake at 500°C for 5 hours.

[0024] Example 2

[0025] Weigh 1.5g of stannous chloride and 0.04g of ferric nitrate, add 10mL of water, stir at room temperature, and after dissolving, add 10g of γ-Al2O3, stir at room temperature for 12h, and dry at 80℃ for 6h. Then place in a muffle furnace and bake at 500℃ for 5h.

[0026] Example 3

[0027] Weigh 2.0 g of stannous chloride and 0.08 g of manganese carbonate, add 20 mL of water, stir at room temperature, and after dissolving, add 20 g of silicon dioxide, stir at room temperature for 6 hours, and dry at 80°C for 6 hours. Then place in a muffle furnace and bake at 600°C for 3 hours.

[0028] Example 4

[0029] Weigh 0.5 g of stannous oxalate and 0.05 g of platinum nitrate, add 10 mL of water, stir at room temperature, and after dissolving, add 10 g of activated carbon, stir at room temperature for 12 h, and dry at 80 ° C for 6 h. Then place in a tube furnace at 500 ° C in a nitrogen atmosphere for 5 h.

[0030] Example 5

[0031] Weigh 1.0 g of stannous sulfate and 0.05 g of nickel nitrate, add 20 mL of water, stir at room temperature, and after dissolving, add 10 g of silicon dioxide, stir at room temperature for 12 hours, and dry at 80°C for 6 hours. Then, place in a muffle furnace and bake at 500°C for 5 hours.

[0032] Application Examples

[0033] The catalyst prepared in Example 1-5 was used to treat the waste gas containing organic volatiles, and the reaction conditions were as follows: The obtained catalyst was used to catalyze the degradation reaction of VOCs, and the conditions were as follows: 0.1g of the catalyst was weighed and placed in a quartz tube (inner diameter 28mm, length 250mm), and a 24W ultraviolet lamp with an excitation light wavelength of 254nm was placed at the upper and lower ends of the quartz tube. Under room temperature, a 2000 ℃ quartz tube containing 2mg / m 3 The gas passed through the quartz tube at a gas flow rate of 0.5 L / min, and the VOCs degradation rate was analyzed by gas chromatography. The results are shown in Table 1.

[0034] Table 1 Degradation effect of the catalysts of Examples 1 to 5 on waste gas containing volatile organic matter

[0035]

[0036] It can be seen from the experimental results in the table that the catalyst produced by the present invention has an excellent removal rate for various volatile organic pollutants, has a wide range of applications, is simple in preparation method, and has good application prospects.

[0037] The catalyst has a wide working temperature range and can catalyze the degradation of VOCs at room temperature or at a higher temperature (such as above 100°C). The catalyst has strong anti-poisoning performance, is not easy to deactivate, has a long life and good stability.

[0038] When the auxiliary metal is selected as Nb, Ta, Co, or Sm, the degradation rate of the prepared catalyst for the above-mentioned VOCs can be as high as over 99%.

[0039] Comparative Example 1

[0040] Weigh 1.5 g of stannous chloride, add 10 mL of water, stir at room temperature, and after it dissolves, add 10 g of ZSM-5 molecular sieve, stir at room temperature for 12 h, and dry at 80 ° C for 6 h. Then, place it in a muffle furnace and bake it at 500 ° C for 5 h.

[0041] The effect of the catalyst on catalyzing VOCs was tested in the manner of the embodiment, with formaldehyde as the reactant, and the degradation rate was 74%.

[0042] Comparative Example 2

[0043] Weigh 1.5 g of stannous chloride and 0.2 g of sodium chloride, add 10 mL of water, stir at room temperature, and after dissolving, add 10 g of ZSM-5 molecular sieve, stir at room temperature for 12 h, and dry at 80 ° C for 6 h. Then place in a muffle furnace and bake at 500 ° C for 5 h.

[0044] The effect of the catalyst on catalyzing VOCs was tested in the manner of the embodiment, with formaldehyde as the reactant, and the degradation rate was 49%.

[0045] Comparative Example 3

[0046] Weigh 1.0 g of dibutyltin and 2.0 g of cerium nitrate, add 20 mL of water, stir at room temperature, and after dissolving, add 10 g of silicon dioxide, stir at room temperature for 12 h, and dry at 80° C. for 6 h. Then, place in a muffle furnace and roast at 300° C. for 3 h.

[0047] Under the above-mentioned catalytic VOCs reaction conditions, the catalyst uses formaldehyde as a reactant and has a degradation rate of 67%.

[0048] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for photocatalytic degradation of VOCs, characterized in that: The photocatalytic catalyst includes tin oxide, metal auxiliary oxide and carrier, wherein the metal auxiliary is one of Mn, Ni, Pt and Ce, the molar ratio of tin element to metal auxiliary element is 1-100:1, the mass ratio of tin oxide to carrier is 1-30:100, and the carrier is one or more of γ-Al2O3, ZSM-5, silicon dioxide and activated carbon; The preparation method of the catalyst comprises: preparing a tin source precursor and a metal auxiliary agent precursor into a solution in a certain proportion, adding a carrier after they are completely dissolved, stirring for a certain time and then drying, and then roasting at a certain temperature to obtain the catalyst; the roasting temperature is 500-600°C and the roasting time is 3-5h.

2. The method according to claim 1, characterized in that The tin source precursor includes any one or more of tin chloride, stannous chloride, stannous oxalate, dibutyltin, stannous octoate, dimethyltin, tetraphenyltin, and dioctyltin.

3. The method according to claim 1, characterized in that: The metal additive precursor is a soluble compound of the metal additive.

4. The method according to claim 1, characterized in that The metal additive precursor includes one or more of manganese nitrate, manganese carbonate; nickel nitrate, nickel sulfate, nickel sulfonate; platinum dichloride, platinum nitrate; cerium sulfate, cerium nitrate, cerium chloride, cerium carbonate, cerium oxalate, and cerium acetate.

5. The method according to claim 1, characterized in that After the precursor solution is mixed with the carrier, the stirring time is 2-24 hours and the stirring temperature is 0-60°C.

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