Platinum-tin bimetallic functional catalyst and preparation method and application thereof in chlorine-containing volatile pollution organic compounds

Abstract

The application discloses a platinum-tin bimetallic functional catalyst and a preparation method and application thereof in chlorinated volatile organic compounds, and the preparation method comprises the following steps: mixing an isopropyl alcohol solution of SnCl4.5H2O or SnCl2.2H2O with an isopropyl alcohol solution containing diethylenetriamine and titanium isopropyl alcohol, then performing hydrothermal reaction, and calcining to obtain a Sn-TiO2 oxide carrier; adding a Pt solution into a water suspension of the Sn-TiO2 oxide carrier, performing reduction reaction after steam drying, and obtaining the platinum-tin bimetallic functional catalyst. The metal composite oxide is prepared by in-situ synthesis of the Sn-TiO2 nanosphere carrier, and the noble metal platinum is uniformly distributed on the surface, which can effectively promote the catalytic degradation of CVOCs, and effectively improve the sulfur resistance of the catalyst. The catalyst of the application can significantly improve the degradation efficiency of the chlorinated VOCs, reduce the treatment cost, and reduce the negative impact on the environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of air pollution control, and particularly relates to a platinum-tin bimetallic functional catalyst, a preparation method thereof and application of the catalyst in treatment of chlorinated volatile organic pollutants. BACKGROUND

[0002] Common air pollution phenomena include acid rain, photochemical smog, ozone layer destruction, and severe haze, all of which not only harm the natural environment but also pose a significant threat to human health. The impact of haze is particularly significant, leading to an increase in respiratory diseases. It is complex in composition, containing nearly 100 compounds harmful to health. Especially fine particles (PM2.5) with a particle size less than 2.5 μm, these fine particles can penetrate deep into the respiratory tract and alveoli, possibly causing a variety of health problems such as acute rhinitis and bronchitis. More worrying is that long-term living in such an environment may increase the risk of lung cancer and damage the cardiovascular system, and even affect mental health, causing depression and other problems. Studies have shown that volatile organic compounds (VOCs) are an important factor in the formation of haze.

[0003] Volatile organic compounds (VOCs) are organic compounds composed of a variety of high-vapor-pressure (>133.32 Pa) and low-boiling-point (50-260℃) organic compounds. Their environmental sources mainly include incomplete combustion of fuel and waste incineration, organic emissions during chemical production (such as oil refining, petrochemicals, coatings, inks, adhesives, pesticides, and pharmaceuticals), and volatile emissions during solvent use, involving printing and packaging, automobile spraying, furniture manufacturing, and other fields. The main components of VOCs include alkanes, aromatic hydrocarbons, alkenes, halogenated hydrocarbons, esters, aldehydes, and ketones.

[0004] Among them, chlorinated hydrocarbons are the focus and difficulty of research due to their environmental persistence, strong toxicity, difficulty in degradation, and generation of various harmful by-products during treatment. Currently, the technologies for treating chlorinated volatile organic compounds (CVOCs) in industrial processes mainly include condensation, absorption, thermal combustion, biological treatment, low-temperature plasma, photocatalysis, and catalytic combustion. Among them, catalytic combustion is widely used in industrial waste gas treatment due to its low energy consumption, simple operation, and environmental protection characteristics.

[0005] Catalysts face relatively complex atmospheric conditions in industrial applications. For example, in pharmaceutical factories, petrochemical industries, and sewage treatment plants, the exhaust gas emitted not only contains CVOCs but also may contain sulfur dioxide (SO2), hydrogen sulfide (H2S), and mercaptans. These chlorinated and sulfur-containing compounds compete with reactants for adsorption of active sites in catalytic reactions, and may also react with main active substances or carriers, causing irreversible chemical deactivation of the catalyst and leading to a decrease in catalytic efficiency.

[0006] In addition, compared with other VOCs, CVOCs are more difficult to be completely oxidized, thus requiring a higher reaction temperature in catalytic combustion process, but the reaction temperature that is too high can promote the generation of dioxin which is a highly toxic substance, and if multiple chlorinated by-products are generated in the catalytic oxidation process, it can further promote the generation of dioxin and polychlorinated dibenzofuran. Therefore, it is particularly important to design a catalyst with excellent low-temperature oxidation-reduction performance so that pollutants can be completely degraded at a lower temperature, good deep oxidation capacity to avoid the generation of multiple chlorinated by-products, and strong anti-poisoning capacity. SUMMARY

[0007] To solve the technical problems of high reaction temperature, multiple by-products and catalyst poisoning in the removal of CVOCs in the prior art, the purpose of the present application is to provide a platinum-tin bimetallic functional catalyst and a preparation method thereof and application thereof in chlorinated volatile pollution organic matter.

[0008] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0009] A preparation method of a platinum-tin bimetallic functional catalyst, comprising the following steps:

[0010] mixing an isopropanol solution of SnCl4·5H2O or SnCl2·2H2O with an isopropanol solution containing diethylenetriamine and titanium isopropanolate to obtain a mixed solution;

[0011] subjecting the mixed solution to hydrothermal reaction to obtain a solid;

[0012] calcining the solid to obtain a Sn-TiO2 oxide carrier;

[0013] adding a Pt solution to an aqueous suspension of the Sn-TiO2 oxide carrier, and after evaporation, subjecting to reduction reaction to obtain a platinum-tin bimetallic functional catalyst.

[0014] Further, the amount ratio of SnCl4·5H2O, diethylenetriamine and titanium isopropanolate is 3.5-7.0 g: 0.05-1 mL: 3.35-6.7 mL, and the amount ratio of SnCl2·2H2O, diethylenetriamine and titanium isopropanolate is 3.5-7.0 g: 0.05-1 mL: 3.35-6.7 mL.

[0015] Further, the temperature of the hydrothermal reaction is 160-200℃, and the time is 24h.

[0016] Further, the temperature is raised to 160-200℃ at a temperature rising rate of 10-20℃ / min.

[0017] Further, the temperature of the calcination is 350-450℃, and the time is 1.5-2.5h.

[0018] Further, the Pt solution is chloroplatinic acid hexahydrate, platinum nitrate, platinum chloride or platinum acetylacetone solution, and the mass ratio of one of chloroplatinic acid hexahydrate, platinum nitrate, platinum chloride and platinum acetylacetone to the Sn-TiO2 oxide carrier is 0.01-0.03:6.

[0019] Further, the temperature of the reduction reaction is 350-450 DEG C, and the time is 1-2 h.

[0020] Further, the reduction reaction is carried out under a mixed gas atmosphere of H2 and Ar, and the temperature is raised to 350-450 DEG C at a temperature raising rate of 1-2 DEG C / min.

[0021] A platinum-tin bimetallic functional catalyst.

[0022] Application of a platinum-tin bimetallic functional catalyst to chlorinated volatile pollution organic matter.

[0023] Compared with the prior art, the present application has the beneficial effects that:

[0024] The present application designs a ternary metal element system, and utilizes the mutual synergistic effect among the ternary metal elements (Pt, Sn and Ti). The Pt element mainly serves to provide low-temperature reduction active sites, so as to promote the complete degradation of pollutants at a lower temperature. The Ti element mainly serves to realize the deep oxidation of the target pollutants, so as to reduce the generation of polychlorinated by-products. The introduction of the Sn element helps to anchor and protect the Pt component, so as to effectively prevent sintering and chlorine poisoning of the Pt component. The ternary metal elements mutually synergize to promote the deep oxidation of chloroethylene. The present application utilizes a one-step hydrothermal method, so that the prepared catalyst has a large specific surface area, and can effectively promote the transmission and transfer of the target pollutants on the surface of the catalytic material. In the present application, the noble metal platinum can be highly dispersed on the surface of the carrier, so as to have excellent low-temperature reducibility and acid-base sites.

[0025] According to the emission characteristics and molecular characteristics of the chlorinated volatile organic matter, the present application develops a platinum-based dispersed ternary metal catalyst with good low-temperature activity, chlorine resistance and carbon deposition resistance, so as to realize high conversion efficiency, strong anti-poisoning ability and good carbon deposition resistance, and realize the environmental-friendly characteristics. In the present application, the hydrothermal reaction and the reduction reaction promote the electron transition of the tin-titanium oxide, so as to vacate oxygen vacancies around the active sites, and then make the platinum element directional anchor and capture. Then, the combination of the thermal reduction promotes the co-reduction between the platinum and the carrier, promotes the electron exchange among the elements, and realizes the design and preparation of the high-efficiency catalyst. The platinum-tin bimetallic functional catalyst for the ternary multifunctional synergistic treatment of the chlorinated volatile organic matter prepared by the present application has excellent low-temperature catalytic activity, good selectivity and outstanding anti-poisoning performance for the chlorinated volatile organic matter. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The H2-TPR curve of the platinum-tin bimetallic functional catalyst catalytic material in the application;

[0027] Figure 2 The O2-TPD curve of the platinum-tin bimetallic functional catalyst catalytic material in the application;

[0028] Figure 3 The BET curve of the specific surface area of the nitrogen adsorption and desorption of the platinum-tin bimetallic functional catalyst catalytic material in the application;

[0029] Figure 4 The activity test curve of the platinum-tin bimetallic functional catalyst catalytic material in the application catalyzing the degradation of vinyl chloride;

[0030] Figure 5 The stability test curve of the platinum-tin bimetallic functional catalyst catalytic material in the application catalyzing the degradation of vinyl chloride in a sulfur dioxide-containing atmosphere. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present application can be more thoroughly and completely understood.

[0032] The preparation method of the platinum-tin bimetallic functional catalyst of the present application uses one-step hydrothermal method, ultrasonic dissolution method, low-temperature step-by-step vacuum drying method, excessive impregnation method, thermal oxidation method, and thermal reduction to prepare the platinum-tin bimetallic functional catalyst material Pt / Sn-TiO2 for the ternary multifunctional synergistic treatment of chlorine-containing volatile organic compounds. The one-step hydrothermal method and the thermal oxidation method are used to promote the electronic transition of tin-titanium oxide in the present application, so as to vacate oxygen vacancies around the active sites, and then the platinum element is anchored and captured in a directional manner, and then the thermal reduction is combined to promote the co-reduction between platinum and the carrier, promote the electronic exchange between the elements, and realize the design and preparation of high-efficiency catalyst. The ternary multifunctional synergistic treatment of chlorine-containing volatile organic compounds of the platinum-tin bimetallic functional catalyst prepared by the present application has excellent low-temperature catalytic activity for chlorine-containing volatile organic compounds and outstanding chlorine resistance. The specific steps are as follows:

[0033] (1) Dissolve 3.5-7.0 g of SnCl4·5H2O or SnCl2·2H2O in a certain amount (1-2 mL) of isopropyl alcohol, and ultrasonically treat the solution with a variable wave ultrasonic machine at room temperature for 5-6 min (ultrasonic frequency 40 kHz), and constantly oscillate the solution until it is completely dissolved and a clear and transparent solution A is formed;

[0034] (2) 0.05-1 mL diethylenetriamine is added dropwise into 70-150 mL isopropyl alcohol, stirred at 400-600 r / min at room temperature for 5 min until the liquid is completely mixed and a clear and transparent solution B is formed;

[0035] (3) 3.35-6.7 mL titanium isopropoxide is quickly added into the solution B in step (2), and then stirred at 400-600 r / min at room temperature for 2-5 min until the liquid is completely mixed and a clear and transparent solution C is formed;

[0036] (4) 0.5 mL of the solution A in step (1) is added dropwise into the solution C in step (3) at a dropwise speed of 10-15 drops / min to obtain a mixed solution. Then the mixed solution is stirred at 400-600 r / min at room temperature for 5-10 min, and then the solution is subjected to ultrasonic wave for 5-6 min (ultrasonic frequency 40 kHz) at 20-25 °C while the solution is constantly shaken until completely dissolved and a clear and transparent solution D is formed;

[0037] (5) 70 mL of the solution D in step (4) is transferred into a stainless steel reaction kettle with a capacity of 100 mL and a Teflon lining. The reaction kettle is placed in an oven, heated to 160-200 °C at a heating rate of 10-20 °C / min and kept for 24 h to obtain a solid-liquid mixture;

[0038] (6) The solid-liquid mixture obtained in step (5) is collected by centrifugation. The centrifuge is rotated at a speed of 7500-8500 r / min for 3-7 min.

[0039] (7) The obtained solid is washed with anhydrous ethanol for several times to obtain a light yellow powder, and then the light yellow powder is dried in an oven at 60-80 °C for 18-28 h until the powder is dried. The obtained sample is calcined in a muffle furnace at 350-450 °C for 1.5-2.5 h to obtain a Sn-TiO2 oxide carrier with high specific surface area;

[0040] (8) 0.6 g of the Sn-TiO2 oxide carrier with high specific surface area is taken into a 100 mL Erlenmeyer flask, 20 mL of deionized water is added, and the carrier is uniformly dispersed by ultrasonic wave. Then the mixture is stirred at 400-600 r / min at room temperature for 2-5 min to obtain a suspension E.

[0041] (9) 1 g of chloroplatinic acid hexahydrate, platinum nitrate, platinum chloride or platinum acetylacetonate is added into 10 mL of deionized water, and stirred at 400-600 r / min at room temperature for 5-10 min until the liquid is completely mixed and a light yellow clear and transparent solution is formed, which is a Pt solution.

[0042] (10) Take the Pt solution obtained in step (9) 0.01~0.03mL dropwise into the suspension E in step (8), then put the flask on the rotary evaporator, under the condition of temperature 50℃, rotation speed 130r / min, first set the vacuum degree to-20KPa and evaporate for 2h, then set the vacuum degree to-90KPa until the solution is evaporated to dryness, to obtain the sample;

[0043] (11) Put the sample obtained in step (10) into a tube furnace, under the condition of mixed gas of H2 and Ar (H2 volume percentage content is 10~20%), heating rate 1~2℃ / min to 350~450℃, reduce for 1~2h, to obtain the platinum-tin bimetallic functional catalyst with high specific surface area, namely Pt / Sn-TiO2.

[0044] Through steps (4)-(7) and the catalytic material prepared in steps (7) under low-temperature step-by-step vacuum drying and thermal reduction, the noble metal platinum can be highly dispersed on the surface of the carrier and can be directionally anchored on the Sn species, so that the catalyst has higher Pt species dispersion, excellent low-temperature reducibility and rich acid-base sites.

[0045] The catalyst prepared in the application has a large specific surface area, which can effectively promote the transmission and transfer of target pollutants on the surface of the catalytic material.

[0046] The catalyst prepared under low-temperature step-by-step vacuum drying and thermal reduction makes the noble metal platinum highly dispersed on the surface of the carrier, so that it has excellent low-temperature reducibility and acid-base sites.

[0047] The catalyst prepared in the application contains ternary metal elements (Pt, Sn, Ti), which synergize with each other. Pt mainly provides low-temperature reduction active sites in the system, Ti elements mainly realize the deep oxidation of target pollutants, and the directional anchoring of Pt elements on Sn sites limits Pt sintering and prevents Pt elements from being chlorinated, so as to protect the stability of catalyst activity, and the three metal elements synergize with each other to promote the deep oxidation of chloroethylene.

[0048] The catalyst of the application can be applied in chlorinated volatile pollution organic matter, and the catalyst can realize 90% degradation of chloroethylene in industrial typical CVOCs at about 270℃ under the condition of reaction space velocity 40000~50000ml·h -1 ·g -1 , oxygen concentration 10~21%, and the activity does not decrease for at least 55h under the condition of 200ppm SO2 being introduced.

[0049] Example 1: Platinum-tin bimetallic functional catalyst catalytic material is prepared by one-step hydrothermal method, ultrasonic dissolution method, low-temperature step-by-step vacuum drying method, excess impregnation method, thermal oxidation method and thermal reduction;

[0050] SnCl4-5H2O (5.25 g) was dissolved in a certain amount (1.5 mL) of isopropanol, and the solution was ultrasonically vibrated at room temperature for 5 min (ultrasonic frequency 40 kHz) and constantly shaken until completely dissolved and a clear transparent solution was formed. Then 0.05 mL of diethylenetriamine was added dropwise to 70.5 mL of isopropanol, and the liquid was stirred at 500 r / min at room temperature for 5 min until completely mixed and a clear transparent solution was formed. Then 3.35 mL of titanium isopropanolate was quickly added to the transparent solution, and then the liquid was stirred at 500 r / min at room temperature for 5 min to fully mix. Then 0.5 mL of Sn solution was added dropwise (the dropwise adding speed was controlled at 15 drops / min), and then the mixed solution was stirred at 500 r / min at room temperature for 5 min. Then the solution was ultrasonically vibrated at 20 °C for 6 min and constantly shaken until completely dissolved. The shaken solution was placed in a reaction kettle and heated to 200 °C at a heating rate of 20 °C / min and reacted for 24 h, and then washed with anhydrous ethanol by centrifugation (the centrifuge speed was 7500 r / min, and the centrifugation time was 7 min). After drying in an oven at 60 °C for 24 h, the powder was calcined in a muffle furnace at 400 °C for 2 h. After obtaining the sample, the excess deionized water was used to disperse the carrier, and then 0.03 mL of H2PtCl6-6H2O aqueous solution (1 g of H2PtCl6-6H2O was added to 10 mL of deionized water, and stirred at 400 r / min at room temperature for 7 min) was added dropwise. After uniform stirring, the rotary evaporator was used to evaporate at a temperature of 50 °C and a speed of 130 r / min. First, the vacuum degree was set to -20 KPa and evaporated for 2 h, and then the vacuum degree was set to -90 KPa until the solution was evaporated. Finally, the obtained sample was placed in a tube furnace, and reduced at 400 °C under the condition of 10% H2 / Ar atmosphere at a heating rate of 2 °C / min for 1 h to obtain a Pt / Sn-TiO2 ternary metal catalyst with high specific surface area, i.e., a platinum tin bimetallic functional catalyst.

[0051] Activity test and evaluation of the platinum tin bimetallic functional catalyst in catalytic degradation of vinyl chloride:

[0052] The solid powder obtained in Example 1 was tabletted and sieved (40-60 mesh), and 0.5 g of the sieved catalyst material was accurately weighed. Vinyl chloride was used as the probe gas, the concentration of the reactant was controlled at 1000 ppm, the reaction space velocity was 42000 mL / g·h, and the oxygen concentration was 15%. The catalytic reaction activity of the catalyst at different temperatures (90, 150, 200, 250, 270, 290 and 300 °C) was tested, and the reaction products were monitored and analyzed by gas chromatography.

[0053] Stability test of the platinum tin bimetallic functional catalyst in catalytic degradation of vinyl chloride:

[0054] The solid powder obtained in Example 1 was tabletted, sieved (40-60 mesh), and 0.5 g of the sieved catalytic material was accurately weighed and placed in the fixed bed of the evaluation device. Vinyl chloride was used as the probe gas, the concentration of the reactants was controlled at 1000 ppm, the SO2 concentration was 200 ppm, and the reaction space velocity was 42000 h -1 and the oxygen concentration was 15%. The catalytic activity of the catalyst at 270 °C was continuously tested, and the reaction products were monitored and analyzed by gas chromatography.

[0055] Analysis of the intermediate products catalyzed by the platinum-tin bimetallic functional catalyst in the degradation of vinyl chloride:

[0056] The solid powder obtained in Example 1 was tabletted, sieved (40-60 mesh), and 0.5 g of the sieved catalytic material was accurately weighed and placed in the fixed bed of the evaluation device. Vinyl chloride was used as the probe gas, the concentration of the reactants was controlled at 1000 ppm, the reaction space velocity was 42000 mL / g·h, and the oxygen concentration was 15%. The production of intermediate products by the catalyst at different temperatures (90, 150, 200, 250, 270, 290, and 300 °C) was tested, and the reaction products were monitored and analyzed by gas chromatography and in-situ online mass spectrometry.

[0057] Figure 1 The platinum-tin bimetallic functional catalyst catalytic material is a platinum-tin bimetallic functional catalyst catalytic material. As can be seen from the figure, the platinum-tin bimetallic functional catalyst catalytic material has a reducible peak at 126 °C, indicating that the material has excellent low-temperature reducibility and has great advantages in the field of catalytic oxidation.

[0058] Figure 2 The platinum-tin bimetallic functional catalyst catalytic material is a platinum-tin bimetallic functional catalyst catalytic material. As can be seen from the figure, the platinum-tin bimetallic functional catalyst material has oxygen desorption peaks at 310, 550, 706, and 802 °C, indicating that the material contains a large amount of surface physical / chemical adsorbed oxygen, surface lattice oxygen, and bulk lattice oxygen. This species can promote the deep oxidation of chlorinated volatile organic pollutants.

[0059] Figure 3 The platinum-tin bimetallic functional catalyst catalytic material is a platinum-tin bimetallic functional catalyst catalytic material. As can be seen from the figure, the platinum-tin bimetallic functional catalyst material has a large amount of mesoporous structure on the surface, which can effectively promote the mass transfer and transmission of CVOCs, and can effectively promote the desorption of toxic species on the surface of the material during the reaction.

[0060] Figure 4The activity test curve of the platinum-tin bimetallic functional catalyst catalytic material for vinyl chloride. As can be seen from the figure, the platinum-tin bimetallic functional catalyst material has good low-temperature catalytic performance, and achieves 90% conversion of 1,2-dichloroethane at 270°C and a reaction space velocity of about 42000 ml·h -1 ·g -1 Under the condition, which can basically be used in the current industrial catalytic RCO catalytic reaction device and can achieve good results.

[0061] Figure 5 The stability test curve of the platinum-tin bimetallic functional catalyst catalytic material for vinyl chloride under sulfur-containing conditions. As can be seen from the figure, the platinum-tin bimetallic functional catalyst material can maintain the conversion rate of vinyl chloride at more than 85% within about 55 hours under the condition of 200 ppm SO2 being introduced, a temperature of 270°C, and a reaction space velocity of about 42000 ml·h -1 ·g -1 When, during the reaction process, SO2 may interact with the reactants or the surface of the catalyst to generate sulfate species, thereby promoting the generation of active sites or enhancing the electronic properties of the catalyst, thereby improving the conversion rate of vinyl chloride, the platinum-tin bimetallic functional catalyst material exhibits very excellent sulfur resistance and oxidation stability for chlorine-containing volatile organic compounds.

[0062] Example 2

[0063] SnCl4·5H2O 3.5 g was dissolved in a certain amount (1 mL) of isopropanol, and the solution was ultrasonically treated at room temperature for 5 min (ultrasonic frequency 40 kHz) while being constantly shaken until completely dissolved and a clear transparent solution was formed; 0.05 mL of diethylenetriamine was added dropwise to 70.5 mL of isopropanol, and stirred at 400 r / min at room temperature for 5 min until the liquid was completely mixed and a clear transparent solution was formed. Then 3.35 mL of titanium isopropanate was quickly added to the transparent solution, and then stirred at 400 r / min at room temperature for 2-5 min until the liquid was fully mixed; 0.5 mL of Sn solution was added dropwise (the dropwise adding speed was controlled at 12 drops / min), and then the mixed solution was stirred at 400 r / min at room temperature for 5 min; then the solution was ultrasonically treated at 25 °C for 5 min while being constantly shaken until completely dissolved; the shaken solution was placed in a reaction kettle and heated to 160 °C at a heating rate of 10 °C / min and reacted for 24 h, and then washed with anhydrous ethanol by centrifugation (centrifuge speed was 8000 r / min, centrifugation time was 5 min). After drying in an oven at 60 °C for 28 h, the dried sample was placed in a muffle furnace and calcined at 450 °C for 1.5 h. After obtaining the sample, the excess deionized water was used to disperse the carrier, and then 0.02 mL of aqueous platinum nitrate solution (1 g of platinum nitrate was added to 10 mL of deionized water, and stirred at 600 r / min at room temperature for 5 min) was added dropwise, and after uniform stirring, a rotary evaporator was used to evaporate at a temperature of 50 °C and a speed of 130 r / min, first setting the vacuum degree to -20 KPa for 2 h, and then setting the vacuum degree to -90 KPa until the solution was evaporated to dryness; finally, the obtained sample was placed in a tube furnace, and reduced at a heating rate of 1 °C / min to 350 °C under a H2 volume percentage of 10% H2 / Ar atmosphere for 2 h to obtain a Pt / Sn-TiO2 ternary metal catalyst with high specific surface area, i.e., a platinum tin bimetallic functional catalyst.

[0064] Example 3

[0065] SnCl4·5H2O 7.0 g was dissolved in a certain amount (2 mL) of isopropanol, and the solution was ultrasonically vibrated at room temperature for 6 min (ultrasonic frequency 40 kHz) and constantly shaken until completely dissolved and a clear transparent solution was formed. 0.05 mL of diethylenetriamine was added dropwise to 70.5 mL of isopropanol, and stirred at 600 r / min at room temperature for 5 min until the liquid was completely mixed and a clear transparent solution was formed. Then 3.35 mL of titanium isopropanate was quickly added to the transparent solution, and then stirred at 600 r / min at room temperature for 2-5 min to fully mix the liquid. 0.5 mL of Sn solution was added dropwise (the dropwise adding speed was controlled at 15 drops / min), and then the mixed solution was stirred at 600 r / min at room temperature for 8 min. Then the solution was ultrasonically vibrated at 22 °C for 6 min and constantly shaken until completely dissolved. The shaken solution was placed in a reaction kettle and heated to 180 °C at a heating rate of 15 °C / min and reacted for 24 h, and then washed with anhydrous ethanol by centrifugation (centrifuge speed was 8500 r / min, centrifugation time was 7 min). After drying in an oven at 80 °C for 18 h, the dried sample was placed in a muffle furnace and calcined at 380 °C for 2.0 h. After obtaining the sample, the excess deionized water was used to disperse the carrier, and then 0.01 mL of aqueous platinum chloride solution (1 g of platinum chloride was added to 10 mL of deionized water, and stirred at 400 r / min at room temperature for 10 min) was added dropwise. After uniform stirring, the rotary evaporator was used to evaporate at a temperature of 50 °C and a speed of 130 r / min. First, the vacuum degree was set to -20 KPa and evaporated for 2 h, and then the vacuum degree was set to -90 KPa until the solution was evaporated to dryness. Finally, the obtained sample was placed in a tube furnace, and reduced at 450 °C under a H2 / Ar atmosphere with a H2 volume percentage of 10% at a heating rate of 2 °C / min for 1 h to obtain a Pt / Sn-TiO2 ternary metal catalyst with high specific surface area, i.e., a platinum tin bimetallic functional catalyst.

[0066] Example 4

[0067] 5.0 g of SnCl4·5H2O was dissolved in a certain amount (2 mL) of isopropanol, and the solution was ultrasonically vibrated at room temperature for 5 min (ultrasonic frequency 40 kHz) and constantly oscillated until completely dissolved and a clear transparent solution was formed to obtain a Sn solution; 0.05 mL of diethylenetriamine was added dropwise into 70.5 mL of isopropanol, and stirred at 500 r / min for 5 min at room temperature until the liquid was completely mixed and a clear transparent solution was formed. Then 3.35 mL of titanium isopropanate was quickly added to the transparent solution, and then the liquid was fully mixed by stirring at 500 r / min for 2-5 min at room temperature; 0.5 mL of Sn solution was added dropwise (the dropwise adding speed was controlled at 10 drops / min), and then the mixed solution was stirred at 500 r / min for 10 min at room temperature; then the solution was ultrasonically vibrated at 20℃ for 6 min, and constantly oscillated until completely dissolved; the oscillated solution was placed in a reaction kettle and heated to 190℃ at a heating rate of 18℃ / min and reacted for 24 h, and then washed with anhydrous ethanol by centrifugation (the centrifuge speed was 7500 r / min, and the centrifugation time was 3 min). After drying in an oven at 70℃ for 25 h, the sample was placed in a muffle furnace at 350℃ for 2.5 h. After obtaining the sample, the excess deionized water was used to disperse the carrier, and then 0.03 mL of aqueous solution of platinum acetylacetone (1 g of platinum acetylacetone was added to 10 mL of deionized water, and stirred at 400 r / min for 10 min at room temperature) was added dropwise, and then the sample was uniformly stirred and evaporated by a rotary evaporator at a temperature of 50℃ and a speed of 130 r / min, first setting the vacuum degree to-20 KPa for 2 h, and then setting the vacuum degree to-90 KPa until the solution was evaporated to dryness. Finally, the obtained sample was placed in a tube furnace, and reduced at 380℃ for 1.5 h under the condition of H2 / Ar gas atmosphere with a H2 volume percentage of 10%, to obtain a Pt / Sn-TiO2 ternary metal catalyst with high specific surface area, i.e., a platinum tin bimetallic functional catalyst.

[0068] The present application can effectively catalyze chlorinated volatile organic compounds (CVOCs) by designing the structure and micro-morphology of the catalyst, combining the properties of the elements, and preparing the catalyst under specific conditions. The metal composite oxide is prepared by in-situ synthesis of Sn-TiO2 nanosphere carriers, and the noble metal platinum is uniformly distributed on the surface, which can effectively promote the catalytic degradation of CVOCs and effectively improve the sulfur resistance of the catalyst. Compared with the prior art, the material of the present application can achieve high efficiency degradation at a lower temperature, reduce energy consumption, has excellent catalytic reaction sustainability, and significantly improves the degradation efficiency of chlorinated VOCs by optimizing the composition, structure and operating conditions of the catalyst, reduces the processing cost, and reduces the negative impact on the environment. The technology provides a solid foundation for the development of new catalysts and their popularization in practical applications, and has good industrial application prospect.

[0069] The above description only illustrates the best mode of the present application and cannot be understood as a limitation to the claims. The present application is not limited to the above embodiments and the specific construction allows variations. Any variations made within the scope of the independent claims are within the scope of the present application.

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Claims

1. Use of a platinum-tin bimetallic functional catalyst in the catalytic degradation of chlorinated volatile organic pollutants, characterized in that, The preparation method of the catalyst comprises the following steps: mixing an isopropanol solution of SnCl4.5H2O or SnCl2.2H2O with an isopropanol solution containing diethylene triamine and titanium isopropanolate to obtain a mixed solution; subjecting the mixed solution to hydrothermal reaction to obtain a solid; subjecting the solid to calcination to obtain a Sn-TiO2 oxide carrier; adding a Pt solution into a water suspension of the Sn-TiO2 oxide carrier, evaporating to dryness, and then performing reduction reaction to obtain a platinum-tin bimetallic functional catalyst; The temperature of the reduction reaction is 350-450 DEG C, and the time is 1-2 h.

2. Use according to claim 1, characterized in that, The amount ratio of SnCl4.5H2O, diethylene triamine and titanium isopropanolate is 3.5-7.0 g:0.05-1 mL:3.35-6.7 mL, and the amount ratio of SnCl2.2H2O, diethylene triamine and titanium isopropanolate is 3.5-7.0 g:0.05-1 mL:3.35-6.7 mL.

3. Use according to claim 1, characterized in that, The temperature of the hydrothermal reaction is 160-200 DEG C, and the time is 24 h.

4. Use according to claim 3, characterized in that, The temperature is raised to 160-200 DEG C at a temperature raising rate of 10-20 DEG C / min.

5. The use according to claim 1, characterized in that, The temperature of the calcination is 350-450 DEG C, and the time is 1.5-2.5 h.

6. Use according to claim 1, characterized in that, The Pt solution is a chloroplatinic acid hexahydrate solution, a platinum nitrate solution, a platinum chloride solution or a platinum acetylacetonate solution, and the mass ratio of one of the chloroplatinic acid hexahydrate solution, the platinum nitrate solution, the platinum chloride solution and the platinum acetylacetonate solution to the Sn-TiO2 oxide carrier is 0.01-0.03:

6.

7. Use according to claim 1, characterized in that, The reduction reaction is performed in a mixed gas atmosphere of H2 and Ar, and the temperature is raised to 350-450 DEG C at a temperature raising rate of 1-2 DEG C / min.

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