A nitrogen-containing organic waste gas treatment catalyst and a method for preparing the same
By constructing a superhydrophobic microenvironment on the catalyst, the problems of catalyst deactivation and secondary pollution under normal temperature and high humidity conditions were solved, achieving efficient removal of dimethylamine and reducing the generation of harmful byproducts, thus improving the stability and efficiency of the catalyst under high humidity conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 江苏洋井环保服务有限公司
- Filing Date
- 2026-04-14
- Publication Date
- 2026-06-09
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of nitrogen-containing organic waste gas treatment technology, and in particular to a water-resistant nitrogen-containing organic waste gas treatment catalyst suitable for normal temperature and high humidity environments and its preparation method. Background Technology
[0002] PU (polyurethane) leather is a type of synthetic leather widely used in bags, clothing, automobiles, and other fields. The waste gases generated during its production mainly consist of N,N-dimethylformamide (DMF), butanone (methyl ethyl ketone), and toluene. Industrially, wet processes such as water-washing absorption towers are typically used to initially intercept the volatile nitrogen-containing organic waste gases. However, the treated exhaust gas still contains low concentrations of dimethylamine, DMF droplets, and other nitrogen-containing organic waste gases. These waste gases have a strong odor and high toxicity, and are often in a high-humidity or even water-saturated state.
[0003] For this type of high-humidity, low-concentration nitrogen-containing organic waste gas, the traditional high-temperature catalytic combustion method not only consumes a huge amount of additional heating energy, but also easily converts nitrogen-containing organic matter into secondary pollutants (nitrogen oxides) at high temperatures. Therefore, room temperature / low-temperature catalytic oxidation technology (such as room temperature ozone-co-catalytic oxidation) has become the most promising technology for treating this type of waste gas.
[0004] Currently, the catalysts used in room temperature catalysis are mainly noble metal or transition metal oxides. However, existing traditional inorganic catalysts have a fatal flaw when treating high-humidity waste gas: water vapor is very easy to condense in the micropores of the catalyst, forming a water film that covers the active sites, hindering the contact between waste gas molecules and the catalyst, leading to rapid "water poisoning" and deactivation of the catalyst.
[0005] Therefore, there is an urgent need to develop a new type of nitrogen-containing organic waste gas treatment catalyst that can maintain high activity under normal temperature and high humidity conditions and effectively resist water vapor interference. Summary of the Invention
[0006] Existing catalysts for treating nitrogen-containing organic waste gases (such as dimethylamine) are prone to capillary water condensation under normal temperature and high humidity (e.g., above 85% RH) conditions due to the hydrophilicity of the support and active components. This leads to water film masking of active sites and blocking gas-solid mass transfer, resulting in rapid catalyst deactivation (water poisoning), incomplete oxidation products (CO), and toxic byproducts (NO). x To address the technical challenge of rapidly increasing nitrogen-containing organic waste gas (NH3), this invention provides a water-resistant catalyst suitable for use in ambient temperature and high humidity environments, as well as its preparation method.
[0007] To achieve the above objectives, the present invention adopts the following technical solution:
[0008] A water-resistant catalyst for treating nitrogen-containing organic waste gas suitable for ambient temperature and high humidity environments, comprising:
[0009] Micron-sized silica carrier;
[0010] An organic-inorganic hybrid crosslinking network is coated on the surface of the carrier. The crosslinking network is formed by covalent crosslinking of polyhedral oligosiloxanes containing aldehyde groups and polyhedral oligosiloxanes containing amino groups, and the crosslinking network contains free carbon-carbon double bonds.
[0011] An active component anchored in the crosslinked network, wherein the active component is a thiol-modified Cu-Pd bimetallic oxide;
[0012] And a long-chain alkyl hydrophobic layer grafted onto the crosslinking network and the outer layer of the active component, wherein the long-chain alkyl hydrophobic layer is formed by grafting a thiol-containing long-chain alkane through a photocatalytic click chemistry reaction.
[0013] Preferably, the organic-inorganic hybrid crosslinking network is composed of in-situ crosslinking of triethoxyaldehyde polyhedral oligosiloxane, amino polyhedral oligosiloxane, vinylaldehyde polyhedral oligosiloxane, and vinyltrialkoxysilane.
[0014] Preferably, the mass ratio of the silica carrier, the triethoxy aldehyde polyhedral oligosiloxane, the amino polyhedral oligosiloxane, and the vinyl aldehyde polyhedral oligosiloxane is 100:(2.4-3.2):3.5:(2.6-3.8) by mass.
[0015] Preferably, the active component is a Cu-Pd composite metal oxide modified with 3-mercaptopropyltriethoxysilane; wherein the molar ratio of Cu to Pd is (10-15):1.
[0016] Preferably, the thiol-containing long-chain alkane is one of 1-dodecyl mercaptan, 1-tetradecyl mercaptan, 1-hexadecyl mercaptan, or 1-octadecyl mercaptan.
[0017] A method for preparing a water-resistant catalyst for treating nitrogen-containing organic waste gas includes the following steps:
[0018] (1) Carrier pretreatment: Micron-sized silica is dispersed in a solvent, and polyhedral oligomeric siloxane containing aldehyde groups is added for reflux reaction to obtain aldehyde-based organic-inorganic hybrid silica material;
[0019] (2) Polymer network construction: The material obtained in step (1) is heated and reacted with amino polyhedral oligosiloxane in a solvent, and then aldehyde polyhedral oligosiloxane containing carbon-carbon double bonds and silane coupling agent containing carbon-carbon double bonds are added to continue the reaction to obtain a functionalized porous carrier.
[0020] (3) Preparation and modification of active components: Cu-Pd composite metal oxide was prepared and its surface was modified by mercaptosilane coupling agent to obtain mercapto-modified Cu-Pd composite metal oxide.
[0021] (4) Long chain modification and loading: The functionalized porous support obtained in step (2) and the long chain alkane containing thiol group are subjected to ultraviolet light reaction in the presence of photoinitiator; then the thiolized Cu-Pd composite metal oxide obtained in step (3) is added, and the click chemical coupling reaction is carried out under ultraviolet light irradiation. After drying, the catalyst is obtained.
[0022] Preferably, in step (2), the reaction solvent is dimethyl sulfoxide, the first stage reaction temperature is 50-70℃, and the reaction time is 5-9h; the second stage reaction temperature after adding aldehyde POSS containing carbon-carbon double bonds is 50-70℃, and the reaction time is 4-8h.
[0023] Preferred: In step (3), the Cu-Pd composite metal oxide is prepared by alkaline precipitation of a mixed solution of palladium chloride and copper nitrate, followed by calcination at 350-450°C for 2-6 hours.
[0024] Preferred:
[0025] Vinyl aldehyde polyhedral oligosiloxane is prepared by the Friedel-Crafts alkylation reaction of vinyl heptaphenyl polyhedral oligosiloxane and methacrolein under anhydrous aluminum chloride catalysis.
[0026] Triethoxyaldehyde polyhedral oligosiloxane is prepared by reacting the vinylaldehyde polyhedral oligosiloxane with triethoxysilane via hydrosilylation reaction in the presence of chloroplatinic acid-isopropanol catalyst.
[0027] Amino polyhedral oligosiloxanes are prepared by reacting 3-aminopropyltriethoxysilane with concentrated hydrochloric acid.
[0028] Application of a nitrogen-containing organic waste gas treatment catalyst in the treatment of organic waste gas at normal temperature and high humidity:
[0029] The waste gas is a mixed waste gas containing dimethylamine, N,N-dimethylformamide or butanone; the normal temperature and high humidity environment refers to the working conditions with a temperature of 15-35℃ and a relative humidity of ≥80%; the treatment method is ozone synergistic catalytic oxidation.
[0030] The beneficial effects of this invention are as follows:
[0031] The core of this invention lies in constructing a supported Cu-Pd / SiO2 catalyst with an embedded multi-linked organic-inorganic hybrid hydrophobic network, the key technical features of which include:
[0032] Dual polyhedral oligosiloxane network coating of micron-scale SiO2 substrate: Trimethoxy aldehyde polyhedral oligosiloxane, amino polyhedral oligosiloxane and vinyl aldehyde polyhedral oligosiloxane are covalently cross-linked through Schiff base reaction and other methods to construct a dense organic-inorganic hybrid micro-nano rough structure in situ on the surface of micron-scale SiO2.
[0033] Anchoring and thiolization bridging of active components: Cu-Pd bimetallic compounds are used as the core active sites for catalytic oxidation / denitrification, and in-situ modification is performed using 3-mercaptopropyltriethoxysilane to provide chemical anchors for subsequent long-chain modifications;
[0034] UV-catalyzed thiol-ene click chemistry grafting: Under UV light initiation, 1-octadecyl mercaptan (long-chain alkyl) is efficiently coupled with the unsaturated bonds / thiol groups on the polyhedral oligosiloxane network and the modified active center to form a hydrophobic barrier with extremely low surface energy on the outermost layer of the catalyst.
[0035] Compared with existing conventional catalysts, this invention constructs a superhydrophobic microenvironment. Through the synergistic effect of the cage-like structure of polyhedral oligosiloxane and the octadecyl long chain, the water contact angle on the catalyst surface reaches as high as 153° (achieving superhydrophobicity). Even under harsh conditions of room temperature and relative humidity as high as 85%, it still maintains no water film adhesion after 200 hours of continuous operation, and the dimethylamine removal rate remains stable at over 96.5% (compared to only 22.4% for conventional catalysts).
[0036] Furthermore, the superhydrophobic network effectively repels the competitive adsorption of water molecules, ensuring the efficient diffusion of dimethylamine molecules and ozone / oxygen radicals to Cu-Pd active sites. This not only promotes the complete oxidation of pollutants (CO selectivity as low as 1.2%, compared to 38.6% conventionally) but also ensures an efficient denitrification process (N2 selectivity as high as 91.8%, compared to 45.3% conventionally), avoiding secondary pollution.
[0037] Furthermore, it was found that in the treatment of complex high-humidity exhaust gases, constructing a superhydrophobic microenvironment through chemical modification to ensure the exposure of effective active sites has a more decisive industrial application value than simply pursuing a large physical specific surface area (conventional catalysts have a larger specific surface area but are rapidly deactivated). Detailed Implementation Example
[0038] A method for preparing a water-resistant nitrogen-containing organic waste gas treatment catalyst I suitable for ambient temperature and high humidity environments includes the following steps:
[0039] (1) Carrier pretreatment: 100g of micron-sized SiO2 particles with a particle size of 5μm were ultrasonically dispersed in 150mL of anhydrous ethanol, and 30mL of triethoxyaldehyde polyhedral oligosiloxane solution was added (3.2g of triethoxyaldehyde polyhedral oligosiloxane was added to 30mL of anhydrous ethanol and ultrasonically dispersed evenly). The mixture was stirred and refluxed at 70℃ for 3h. After the reaction was completed, the mixture was washed 3 times with anhydrous ethanol, filtered, and vacuum dried at 70℃ to constant weight to obtain aldehyde-based organic-inorganic hybrid silica material.
[0040] (2) Construction of polymer network: In a nitrogen atmosphere, the aldehyde-based organic-inorganic hybrid silica material and 3.5 g of amino polyhedral oligosiloxane were added to 100 mL of dimethyl sulfoxide, mechanically stirred until homogeneous, and the temperature was raised to 60 °C. The reaction was carried out for 7 h. After the reaction was completed, 3.8 g of vinyl aldehyde polyhedral oligosiloxane and 0.72 g of vinyltrimethoxysilane were added, mixed well, and the reaction was continued at 60 °C for 6 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and washed 5 times each with deionized water and methanol. The mixture was then vacuum dried at 50 °C for 12 h to obtain the functionalized porous carrier.
[0041] (3) Preparation of active components: 0.53 g palladium chloride was added to 50 mL of deionized water, and the pH value was adjusted with 10% hydrochloric acid until the palladium chloride was completely dissolved to form a brown solution; 4.5 g copper nitrate was added, and the pH value of the system was adjusted to 10 with 0.5 mol / L sodium hydroxide solution under stirring. After stirring for 3 h, the mixture was allowed to stand for 24 h; it was filtered, washed 5 times with deionized water, dried under vacuum at 70 °C for 12 h, and then calcined in a muffle furnace at 400 °C for 4 h to obtain Cu-Pd composite metal oxide;
[0042] (4) Modification of active components: 1 g of Cu-Pd composite metal oxide was added to 20 mL of anhydrous ethanol and ultrasonically dispersed for 20 min; 10 mL of deionized water containing 0.05 g of 3-mercaptopropyltriethoxysilane was added and stirred evenly; the system temperature was raised to 70 °C and refluxed for 4 h; after the reaction was completed, the mixture was filtered, washed, and vacuum dried at 60 °C for 24 h to obtain mercaptolated Cu-Pd composite metal oxide;
[0043] (5) Long chain modification: 100g of functionalized porous support and 1.4g of 1-octadecyl mercaptan were added to toluene and mechanically stirred until homogeneous; 0.1g of benzoin dimethyl ether (as a photoinitiator) was added and stirred for 1h under 365nm ultraviolet light irradiation;
[0044] (6) Active component loading: 10g of mercapto-modified Cu-Pd composite metal oxide was added to the above reaction system, mixed well, and reacted under ultraviolet light for 1h. After the reaction was completed, the solvent was removed by rotary evaporation, and the mixture was washed three times with ethanol and deionized water in sequence. The mixture was then dried in a vacuum drying oven at 40℃ for 12h to obtain nitrogen-containing organic waste gas treatment catalyst I. Example
[0045] A water-resistant nitrogen-containing organic waste gas treatment catalyst II suitable for normal temperature and high humidity environments was prepared. The only difference between it and Example 1 is that the amount of triethoxy aldehyde polyhedral oligosiloxane is 2.4g, the amount of amino polyhedral oligosiloxane is 3.5g, and the amount of vinyl aldehyde polyhedral oligosiloxane is 2.6g. Example
[0046] A water-resistant nitrogen-containing organic waste gas treatment catalyst III suitable for normal temperature and high humidity environments was prepared. The only difference between it and Example 1 is that the amount of triethoxy aldehyde polyhedral oligosiloxane is 2.6g, the amount of amino polyhedral oligosiloxane is 3.5g, and the amount of vinyl aldehyde polyhedral oligosiloxane is 2.9g. Example
[0047] A water-resistant nitrogen-containing organic waste gas treatment catalyst IV suitable for normal temperature and high humidity environments was prepared. The only difference between it and Example 1 is that the amount of triethoxy aldehyde polyhedral oligosiloxane is 3.0g, the amount of amino polyhedral oligosiloxane is 3.5g, and the amount of vinyl aldehyde polyhedral oligosiloxane is 3.5g.
[0048] Preparation of conventional Cu-Pd / SiO2 catalyst: 100g of 5μm micron-sized SiO2 particles were ultrasonically dispersed in deionized water for later use; 0.53g of palladium chloride was added to 50mL of deionized water, and the pH was adjusted with 10% hydrochloric acid until dissolved; 4.5g of copper nitrate was added and stirred evenly; the pH of the system was adjusted to 10 with 0.5mol / L sodium hydroxide solution, stirred for 3h and then allowed to stand for 24h; the above mixed precursor liquid was directly impregnated onto the above SiO2 support in equal volume, stirred for 2h, and then placed in an 80℃ water bath to evaporate the water; then vacuum dried at 70℃ for 12h, and finally calcined in a muffle furnace at 400℃ for 4h to obtain conventional Cu-Pd / SiO2 catalyst.
[0049] To verify the practical application effect of the catalyst of the present invention under normal temperature and high humidity conditions, the performance of the catalysts prepared in Examples 1 to 4 and the comparative examples was tested.
[0050] Test conditions: The test was conducted in a fixed-bed microreactor at a reaction temperature of 25°C and a relative humidity (RH) of 85% for the reaction gas. The simulated nitrogen-containing waste gas was dimethylamine with an initial concentration of 200 ppm, and the gas hourly space velocity (GHSV) was 30,000 h⁻¹. -1 Ozone synergistic catalysis is employed, with an O3 / dimethylamine molar ratio of 2.0, and continuous operation for 200 hours.
[0051] Test methods and evaluation index calculation instructions:
[0052] (1) The exhaust gas was detected in real time using a Fourier transform infrared gas analyzer (FTIR) and a gas chromatograph (GC). The specific calculations are as follows:
[0053] Dimethylamine removal rate (%) = [(inlet dimethylamine concentration - exhaust dimethylamine concentration) / inlet dimethylamine concentration] × 100%;
[0054] N2 selectivity (%) = [1 - (total molar concentration of nitrogen-containing byproducts NO+NO2+N2O+NH3 in exhaust gas) / (inlet dimethylamine concentration - exhaust dimethylamine concentration)] × 100%;
[0055] CO selectivity (%) = [molar concentration of CO in exhaust gas / (molar concentration of CO in exhaust gas + molar concentration of CO2 in exhaust gas)] × 100%.
[0056] (2) The catalyst powder was pressed into tablets at 10 MPa. At room temperature, 4 μL of deionized water was added to the surface of the tablets using a contact angle meter. After the droplets stabilized, the water contact angle (WCA) was recorded and calculated.
[0057] (3) Using a fully automatic specific surface area and porosity analyzer, after the sample was degassed in vacuum at 150℃ for 4 hours, N2 adsorption-desorption test was performed at 77K, and the specific surface area was calculated by BET method.
[0058] The test results are shown in Table 1.
[0059] Table 1. Comparative test results of catalyst performance prepared in different embodiments and comparative examples
[0060]
[0061] The following conclusions can be drawn from the above test data:
[0062] The comparative example, lacking polyhedral oligomeric siloxane and long-chain modification, had a completely hydrophilic surface. Under high humidity (85% RH), water vapor rapidly condensed within the capillaries, forming a water film that masked the active sites, resulting in a precipitous drop in removal rate to 22.4% after 200 hours of operation. In contrast, Examples 1 to 4 of this invention, with the increased amount of polyhedral oligomeric siloxane crosslinking network, transformed the catalyst from ordinary hydrophobic to superhydrophobic. Example 1, benefiting from the superhydrophobic surface (WCA reaching 153°) synergistically constructed by the dense polyhedral oligomeric siloxane network and long-chain alkyl groups, exhibited excellent resistance to water poisoning, achieving a removal rate as high as 96.5% after 200 hours.
[0063] Example 1 effectively repels water vapor adhesion due to its strong hydrophobicity, allowing dimethylamine and reactive radicals to maintain excellent mass transfer efficiency around the Cu-Pd active center, achieving deep mineralization of pollutants (CO selectivity as low as 1.2%) and efficient denitrification (N2 selectivity as high as 91.8%). In contrast, the comparative example suffers from incomplete oxidation due to severe obstruction by the surface water film, resulting in a large number of harmful byproducts (CO selectivity as high as 38.6%).
[0064] BET data shows that the initial specific surface area of the comparative sample is the largest (420m²). 2 / g), but its actual long-term catalytic performance is extremely poor; while Example 1, although having a relatively small specific surface area (245 m²), has a much smaller specific surface area (245 m²), it is still very poor in long-term catalytic performance. 2 / g), due to the unique superhydrophobic microenvironment constructed inside, its actual catalytic efficiency far exceeds that of conventional materials. This fully demonstrates that in the application scenario of this invention, the construction of a micro-hydrophobic barrier is more crucial than simply pursuing a high specific surface area for maintaining the high activity of the catalyst.
[0065] Furthermore, the polyhedral oligomeric siloxane raw material used in the above embodiments was prepared by the following method, the preparation experimental steps of which are as follows:
[0066] Preparation of sodium trisiloxane intermediate: 4.56 g phenyltrimethoxysilane, 50 mL tetrahydrofuran, 0.53 g deionized water and 0.4 g sodium hydroxide were added to a 250 mL volumetric flask and refluxed at 70 °C for 5 h. After cooling to room temperature, the reaction was continued for another 15 h. After the reaction was completed, the solvent and other volatile components were removed by rotary evaporation. The intermediate was then dried under vacuum at 40 °C for 24 h to obtain sodium trisiloxane intermediate.
[0067] Preparation of vinylheptaphenyl polyhedral oligosiloxane: 3.01 g of sodium trisiloxane intermediate was dissolved in 40 mL of dried tetrahydrofuran. The system was placed in an ice bath to cool to 0 °C. Then, 0.72 g of vinyltrichlorosilane was rapidly added under strong stirring. The reaction was carried out at 0 °C for 1 h, and then removed and reacted at room temperature for 24 h. After the reaction was completed, the insoluble solids were filtered off, and the volatile components were removed by rotary evaporator. The mixture was washed three times with 100 mL of methanol, recrystallized, and dried in a vacuum drying oven at 40 °C for 24 h to obtain vinylheptaphenyl polyhedral oligosiloxane.
[0068] Preparation of vinyl aldehyde-based polyhedral oligosiloxane: Under nitrogen protection, 9.8 g of vinyl heptaphenyl polyhedral oligosiloxane, 10 g of anhydrous aluminum chloride, and 100 mL of 1,2-dichloroethane were added to a 250 mL three-necked flask. The mixture was magnetically stirred for 15 min, and 5.9 mL of methacrolein was added dropwise over a period of 30 min. The system temperature was raised to 80 °C, and the reaction was allowed to proceed for 6 h. After the reaction was completed, the mixture was placed in a beaker containing 80 g of crushed ice. After separation, the mixture was washed three times with deionized water, a 1% aqueous solution of W(Na2CO3), and deionized water, respectively. The mixture was then dried in a vacuum drying oven at 50 °C for 48 h to obtain vinyl aldehyde-based polyhedral oligosiloxane.
[0069] Preparation of triethoxyaldehyde polyhedral oligosiloxane: 10.3 g of vinylaldehyde polyhedral oligosiloxane and 2 mL of chloroplatinic acid-isopropanol catalyst (0.25 g of chloroplatinic acid was completely dissolved in 25 mL of anhydrous isopropanol and allowed to stand for 24 h to obtain the chloroplatinic acid-isopropanol catalyst) were added to 100 mL of anhydrous toluene and mechanically stirred until homogeneous. 1.15 g of triethoxysilane was then added. After the addition was complete, heating was started and the temperature was controlled at 70 °C. The reaction was carried out for 24 h under nitrogen protection. After the reaction was completed, the mixture was naturally cooled to room temperature. 0.8 g of dry activated carbon (adsorption catalyst) was added and stirred for 30 min. The mixture was filtered, and toluene was removed by rotary evaporation. The mixture was then vacuum dried at 60 °C for 24 h to obtain triethoxyaldehyde polyhedral oligosiloxane.
[0070] Preparation of amino polyhedral oligosiloxane: 50 mL of 3-aminopropyltriethoxysilane was added to a 1000 mL three-necked flask, and 400 mL of anhydrous methanol was added. The mixture was magnetically stirred for 10 min. Under stirring, 126 mL of concentrated hydrochloric acid solution was added dropwise. During this process, white mist was observed to be generated. After the addition was completed, the flask was kept sealed and the reaction was stirred at room temperature for 2 days. Then, the mixture was allowed to stand for 5 days. A large amount of white precipitate was generated at the bottom of the flask. The solid product was washed 5 times with methanol and dried in a forced-air dryer at 50 °C for 8 h to obtain amino polyhedral oligosiloxane.
Claims
1. A water-resistant catalyst for treating nitrogen-containing organic waste gas suitable for normal temperature and high humidity environments, characterized in that, include: Micron-sized silica carrier; An organic-inorganic hybrid crosslinking network is coated on the surface of the carrier. The crosslinking network is formed by covalent crosslinking of polyhedral oligosiloxanes containing aldehyde groups and polyhedral oligosiloxanes containing amino groups, and the crosslinking network contains free carbon-carbon double bonds. An active component anchored in the crosslinked network, wherein the active component is a thiol-modified Cu-Pd bimetallic oxide; And a long-chain alkyl hydrophobic layer grafted onto the crosslinking network and the outer layer of the active component, wherein the long-chain alkyl hydrophobic layer is formed by grafting long-chain alkanes containing thiol groups through a photocatalytic click chemistry reaction; The organic-inorganic hybrid crosslinking network is composed of in-situ crosslinking of triethoxy aldehyde polyhedral oligosiloxane, amino polyhedral oligosiloxane, vinyl aldehyde polyhedral oligosiloxane, and vinyltrialkoxysilane. The mass ratio of the silica carrier, the triethoxy aldehyde polyhedral oligosiloxane, the amino polyhedral oligosiloxane, and the vinyl aldehyde polyhedral oligosiloxane, by mass, is 100:(2.4-3.2):3.5:(2.6-3.8). The active component is a Cu-Pd composite metal oxide modified with 3-mercaptopropyltriethoxysilane; wherein the molar ratio of Cu to Pd is (10-15):
1.
2. The nitrogen-containing organic waste gas treatment catalyst according to claim 1, characterized in that: The thiol-containing long-chain alkane is one of 1-dodecyl mercaptan, 1-tetradecyl mercaptan, 1-hexadecyl mercaptan, or 1-octadecyl mercaptan.
3. A method for preparing a water-resistant nitrogen-containing organic waste gas treatment catalyst as described in claim 1 or 2, characterized in that, Includes the following steps: (1) Carrier pretreatment: Micron-sized silica is dispersed in a solvent, and polyhedral oligomeric siloxane containing aldehyde groups is added for reflux reaction to obtain aldehyde-based organic-inorganic hybrid silica material; (2) Polymer network construction: The material obtained in step (1) is heated and reacted with amino polyhedral oligosiloxane in a solvent, and then aldehyde polyhedral oligosiloxane containing carbon-carbon double bonds and silane coupling agent containing carbon-carbon double bonds are added to continue the reaction to obtain a functionalized porous carrier. (3) Preparation and modification of active components: Cu-Pd composite metal oxide was prepared and its surface was modified by mercaptosilane coupling agent to obtain mercapto-modified Cu-Pd composite metal oxide. (4) Long chain modification and loading: The functionalized porous support obtained in step (2) and the long chain alkane containing thiol group are subjected to ultraviolet light reaction in the presence of photoinitiator; then the thiolized Cu-Pd composite metal oxide obtained in step (3) is added, and the click chemical coupling reaction is carried out under ultraviolet light irradiation. After drying, the catalyst is obtained.
4. The preparation method according to claim 3, characterized in that: In step (2), the reaction solvent is dimethyl sulfoxide, the reaction temperature of the first stage is 50-70℃, and the reaction time is 5-9h; the reaction temperature of the second stage after adding aldehyde POSS containing carbon-carbon double bonds is 50-70℃, and the reaction time is 4-8h.
5. The preparation method according to claim 3, characterized in that: In step (3), the Cu-Pd composite metal oxide is prepared by alkaline precipitation of a mixed solution of palladium chloride and copper nitrate, followed by calcination at 350-450℃ for 2-6 hours.
6. The preparation method according to claim 3, characterized in that: Vinyl aldehyde polyhedral oligosiloxane is prepared by the Friedel-Crafts alkylation reaction of vinyl heptaphenyl polyhedral oligosiloxane and methacrolein under anhydrous aluminum chloride catalysis. Triethoxyaldehyde polyhedral oligosiloxane is prepared by reacting the vinylaldehyde polyhedral oligosiloxane with triethoxysilane via hydrosilylation reaction in the presence of chloroplatinic acid-isopropanol catalyst. Amino polyhedral oligosiloxanes are prepared by reacting 3-aminopropyltriethoxysilane with concentrated hydrochloric acid.
7. The application of a nitrogen-containing organic waste gas treatment catalyst as described in claim 1 or 2 in the treatment of organic waste gas at room temperature and high humidity, characterized in that: The waste gas is a mixed waste gas containing dimethylamine, N,N-dimethylformamide or butanone; the normal temperature and high humidity environment refers to the working conditions with a temperature of 15-35℃ and a relative humidity of ≥80%; the treatment method is ozone synergistic catalytic oxidation.
Citation Information
Patent Citations
Application of polyoxometalate / silicon dioxide catalyst in controllable oxidization of sulfide
CN101550044A
Method for preparing super-hydrophobicity surfaces
CN102863154A