阅读说明：本技术 一种锡掺杂铂钛催化剂及其制备方法和应用 (Tin-doped platinum-titanium catalyst and preparation method and application thereof ) 是由 陈建军 刘海岩 史建强 王桂敏 李俊华 于 2020-05-08 设计创作，主要内容包括：本发明公开了一种锡掺杂铂钛催化剂及其制备方法和应用,锡掺杂铂钛催化剂的组成表示为Pt/Sn<Sub>x</Sub>Ti<Sub>1-x</Sub>O<Sub>2</Sub>,锡掺杂铂钛催化剂中各组分的协同催化效应,使其具有良好的活性和抗水抗硫性能。通过共沉淀和浸渍合成的方法,发挥三组分间的强相互作用,形成一种金红石相固溶体结构,该结构具有较高比表面积和结构稳定性,有更多的活性位参与反应。同时锡的掺杂促进了电子在活性组分间的传递,催化剂表面氧空位增多,促进了反应物分子的吸附与活化,有效提高了催化剂的CO氧化性能和抗水和抗硫中毒性能。降低了一氧化碳完全氧化的温度,具有良好的一氧化碳催化氧化性能。锡掺杂铂钛催化剂遇SO<Sub>2</Sub>和水不失活,能够有效脱除厂房固定源和车移动源排放的一氧化碳。(The invention discloses a tin-doped platinum-titanium catalyst and a preparation method and application thereof, wherein the tin-doped platinum-titanium catalyst is expressed by the composition of Pt/Sn x Ti 1‑x O 2 The tin-doped platinum-titanium catalyst has good activity, water resistance and sulfur resistance due to the synergistic catalytic effect of the components. Through a coprecipitation and impregnation synthesis method, strong interaction among three components is exerted to form a rutile phase solid solution structure, and the structure has high specific surface area and structural stability and has more active sites participating in reaction. Meanwhile, the doping of tin promotes the transfer of electrons among active components, so that oxygen vacancies on the surface of the catalyst are increased, the adsorption and activation of reactant molecules are promoted, and the improvement is effectiveThe CO oxidation performance and the water and sulfur poisoning resistance of the catalyst are improved. The temperature for completely oxidizing the carbon monoxide is reduced, and the catalyst has good carbon monoxide catalytic oxidation performance. Tin-doped platinum-titanium catalyst meets SO 2 And water is not inactivated, so that carbon monoxide discharged by plant fixed sources and vehicle moving sources can be effectively removed.)

1. The tin-doped platinum-titanium catalyst is characterized by being prepared from a chloroplatinic acid solution with the concentration of 0.05 mmol/L, a tin tetrachloride solution with the concentration of 0-1.6 mol/L and a titanium sulfate solution with the concentration of 1-2 mol/L, wherein the tin-doped platinum-titanium catalyst is expressed by the composition of Pt/Sn_xTi_1-xO₂Wherein the loading amount of Pt is 0.1-1%, x is the molar ratio of Sn/(Sn + Ti), and x is more than 0 and less than or equal to 0.5.

2. The preparation method of the tin-doped platinum-titanium catalyst is characterized by comprising the following steps of:

s1, preparing a chloroplatinic acid solution with the concentration of 0.05 mmol/L, a 0-1.6 mol/L stannic chloride solution and a 1-2 mol/L titanium sulfate solution, and standing for later use after the preparation is finished;

s2, mixing the tin tetrachloride solution and the titanium sulfate solution prepared in the step S1, and uniformly stirring to obtain a mixed solution;

s3, dropwise adding ammonia water into the mixed solution obtained in the step S2 while stirring, adjusting the pH value to 10-11, and then uniformly stirring to obtain a reaction solution;

s4, carrying out suction filtration, washing and drying on the reaction liquid, and then putting the reaction liquid into a muffle furnace for roasting to obtain a tin-titanium composite oxide;

s5, adding a proper amount of chloroplatinic acid solution prepared in the step S1 into the tin-titanium composite oxide, and stirring for a period of time at room temperature to obtain a slurry-like mixture;

and S6, drying the slurry mixture obtained in the step S5, and then putting the dried slurry mixture into a muffle furnace for roasting to finally obtain the tin-doped platinum-titanium catalyst.

3. The method for preparing the tin-doped platinum-titanium catalyst according to claim 2, wherein in the step S4, the drying is specifically carried out at 120 ℃ for 12-24 h; placing into a muffle furnace for roasting at 500 ℃ for 4-8 h.

4. The method for preparing a tin-doped platinum-titanium catalyst according to claim 2, wherein the step S6 specifically comprises: the slurry mixture was dried at 120 ℃ for 12-24h and then calcined in a muffle furnace at 500 ℃ for 1 h.

5. The method of claim 2, wherein the stirring time in step S2 is 30-90 min.

6. The method of claim 2, wherein the stirring time at room temperature in step S5 is 2-4 h.

7. The use of the tin-doped platinum titanium catalyst as claimed in claim 1 or 2, wherein the tin-doped platinum titanium catalyst is placed in a flowing fixed bed reactor and is first placed in a reactor with a concentration of 10% H at 20ml/min₂Mixed gas of/He, 80ml/min N₂Under the atmosphere, 500^oC, pretreating for 1 hour, and then cooling the fixed bed reactor filled with the tin-doped platinum-titanium catalyst to room temperature; and after the reaction is finished, introducing reaction gas into the fixed bed reactor, performing catalytic oxidation, and removing CO in the reaction gas.

8. The application of the tin-doped platinum titanium catalyst as claimed in claim 7, wherein the introduced reaction gas is specifically: shut off 10% H₂The mixed gas of the/He, the reaction gas is introduced into the fixed bed reactor: 0.004% NO、1%CO、10%O₂、15%H₂O, use of N₂As balance gas, the flow rate of the reaction gas is 100m L/min, and the space velocity is 53000h^-1And the activity evaluation temperature range is 100-280 ℃, and the conversion rate of CO catalytically oxidized by the catalyst at different temperatures is tested.

9. The application of the tin-doped platinum titanium catalyst as claimed in claim 7, wherein the introduced reaction gas is specifically: shut off 10% H₂Heating the fixed bed reactor to 250 ℃ by using a mixed gas of the gas/He, and introducing a reaction gas, wherein the reaction gas comprises the following components: 0.004% NO, 1% CO, 10% O₂、15%H₂O, use of N₂As balance gas, the flow rate of the reaction gas is 100m L/min, and the space velocity is 53000h^-1After reacting for 1h, continuously introducing 0.02 percent SO₂And reacting for 20h, and testing the catalytic oxidation CO conversion rate of the catalyst at different time points.

10. Use of a tin-doped platinum titanium catalyst according to claim 7, wherein the tin-doped platinum titanium catalyst is used for removing carbon monoxide emitted from stationary plant sources and mobile vehicle sources.

Technical Field

The invention belongs to the technical field of environmental catalytic materials and environmental protection, and particularly relates to a tin-doped platinum-titanium catalyst and a preparation method and application thereof.

Background

CO is one of the most common pollutants in the atmosphere, mainly from fuel combustion and automotive exhaust. CO is a choking gas and generally does not cause harm due to the diffusion and dilution and oxidation of the atmosphere after entering the atmosphere. However, in the winter heating season of the city or at the crossroads with heavy traffic, when the meteorological conditions are not favorable for exhaust diffusion and dilution, the concentration of CO may reach the level harmful to human health. The CO is mainly from exhaust gas discharged by motor vehicle tail gas, steel making, iron making, coke oven, gas generating station, heating boiler, civil stove and solid waste incineration. Emission control has become a research focus in the field of environmental catalysis and atmospheric control. Catalytic combustion (catalytic combustion) carbon monoxide is the most widely used carbon monoxide removal technology at present, and the key of the catalytic combustion technology is a high-efficiency stable catalyst. At present, precious metal catalysts are mostly researched, and precious metal nanoparticles such as Pt, Ru and Au are highly dispersed on the surfaces of certain metal oxides to have good catalytic performance for CO oxidation. However, SO₂Is an inevitable constituent of the exhaust gas generated by the combustion of coal because coal contains sulfur impurities. SO (SO)₂And the presence of water promotes the deactivation of noble metal catalysts such as Pt, Ru and Au. Therefore, the development of a novel efficient water-resistant and sulfur-resistant carbon monoxide catalytic oxidation catalyst has very important environmental significance for eliminating CO, and is an urgent need of the environmental protection industry of China.

Disclosure of Invention

The invention provides a tin-doped platinum-titanium catalyst, a preparation method and application thereof, and solves the problem that the noble metal catalyst meets SO₂And water deactivation.

In order to solve the technical problem, the technical scheme adopted by the invention is that the tin-doped platinum titanium catalyst is prepared from a chloroplatinic acid solution with the concentration of 0.05 mmol/L, a tin tetrachloride solution with the concentration of 0-1.6 mol/L and a titanium sulfate solution with the concentration of 1-2 mol/L, wherein the tin-doped platinum titanium catalyst is represented by the composition Pt/Sn_xTi_1-xO₂Wherein the loading amount of Pt is 0.1-1%, x is the molar ratio of Sn/(Sn + Ti), and x is more than 0 and less than or equal to 0.5.

A preparation method of a tin-doped platinum-titanium catalyst comprises the following steps:

s1, preparing a chloroplatinic acid solution with the concentration of 0.05 mmol/L, a 0-1.6 mol/L stannic chloride solution and a 1-2 mol/L titanium sulfate solution, and standing for later use after the preparation is finished;

s2, mixing the tin tetrachloride solution and the titanium sulfate solution prepared in the step S1, and uniformly stirring to obtain a mixed solution;

s3, dropwise adding ammonia water into the mixed solution obtained in the step S2 while stirring, adjusting the pH value to 10-11, and then uniformly stirring to obtain a reaction solution;

s4, carrying out suction filtration, washing and drying on the reaction liquid, and then putting the reaction liquid into a muffle furnace for roasting to obtain a tin-titanium composite oxide;

s5, adding a proper amount of chloroplatinic acid solution prepared in the step S1 into the tin-titanium composite oxide, and stirring for a period of time at room temperature to obtain a slurry-like mixture;

and S6, drying the slurry mixture obtained in the step S5, and then putting the dried slurry mixture into a muffle furnace for roasting to finally obtain the tin-doped platinum-titanium catalyst.

Further, in the step S4, the drying is specifically drying at 120 ℃ for 12-24 h; placing into a muffle furnace for roasting at 500 ℃ for 4-8 h.

Further, the step S6 is specifically: the slurry mixture was dried at 120 ℃ for 12-24h and then calcined in a muffle furnace at 500 ℃ for 1 h.

Further, in the step S2, the stirring time is 30-90 min.

Further, in the step S5, the stirring time at room temperature is 2-4 h.

The application of tin-doped platinum-titanium catalyst is characterized by placing the tin-doped platinum-titanium catalyst in a flowing fixed bed reactor, and firstly, 10% H is added in the reactor at a rate of 20ml/min₂Mixed gas of/He, 80ml/min N₂Under the atmosphere, 500^oC, pretreating for 1 hour, and then cooling the fixed bed reactor filled with the tin-doped platinum-titanium catalyst to room temperature; and after the reaction is finished, introducing reaction gas into the fixed bed reactor, performing catalytic oxidation, and removing CO in the reaction gas.

Further, the introduced reaction gas specifically comprises: shut off 10% H₂The mixed gas of the/He, the reaction gas is introduced into the fixed bed reactor: 0.004% NO, 1% CO, 10% O₂、15%H₂O, use of N₂As balance gas, the flow rate of the reaction gas is 100m L/min, and the space velocity is 53000h^-1And the activity evaluation temperature range is 100-280 ℃, and the conversion rate of CO catalytically oxidized by the catalyst at different temperatures is tested.

Further, the introduced reaction gas specifically comprises: shut off 10% H₂Heating the fixed bed reactor to 250 ℃ by using a mixed gas of the gas/He, and introducing a reaction gas, wherein the reaction gas comprises the following components: 0.004% NO, 1% CO, 10% O₂、15%H₂O, use of N₂As balance gas, the flow rate of the reaction gas is 100m L/min, and the space velocity is 53000h^-1After reacting for 1h, continuously introducing 0.02 percent SO₂And reacting for 20h, and testing the catalytic oxidation CO conversion rate of the catalyst at different time points.

Further, the tin-doped platinum titanium catalyst is used for removing carbon monoxide discharged by plant fixed sources and vehicle moving sources.

The invention achieves the following beneficial effects: the tin-doped platinum-titanium catalyst has the synergistic catalytic effect of the components, so that the tin-doped platinum-titanium catalyst has good activity, water resistance and sulfur resistance. Through a coprecipitation and impregnation synthesis method, strong interaction among three components is exerted to form a rutile phase solid solution structure, and the structure has high specific surface area and structural stability and has more active sites participating in reaction. Meanwhile, the doping of tin promotes the transfer of electrons among active components, oxygen vacancies on the surface of the catalyst are increased, and the adsorption and activation of reactant molecules are promoted, andthe CO oxidation performance and the water and sulfur poisoning resistance of the catalyst are effectively improved. The temperature for completely oxidizing the carbon monoxide is reduced, and the catalyst has good carbon monoxide catalytic oxidation performance. Tin-doped platinum-titanium catalyst meets SO₂And water is not inactivated, so that carbon monoxide discharged by plant fixed sources and vehicle moving sources can be effectively removed.

Drawings

FIG. 1 is a graph of the CO conversion of a catalyst at various temperatures according to an example of the present invention;

FIG. 2 shows SO at 0.02% in an example of the present invention₂、15%H₂Graph of conversion of catalytic oxidation CO at different time points under O conditions.

Detailed Description

The invention is further described below. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

A tin-doped platinum-titanium catalyst is prepared from a chloroplatinic acid solution with a concentration of 0.05 mmol/L, a tin tetrachloride solution with a concentration of 0-1.6 mol/L mol and a titanium sulfate solution with a concentration of 1-2 mol/L_xTi_1-xO₂Wherein the loading amount of Pt is 0.1-1%, x is the molar ratio of Sn/(Sn + Ti), and x is more than 0 and less than or equal to 0.5. In this example, the supported amount of Pt was 0.1%.

A preparation method of a tin-doped platinum-titanium catalyst comprises the following steps:

s1, preparing a chloroplatinic acid solution with the concentration of 0.05 mmol/L, a 0-1.6 mol/L stannic chloride solution and a 1-2 mol/L titanium sulfate solution, and standing for later use after the preparation is finished;

s2, mixing the tin tetrachloride solution and the titanium sulfate solution prepared in the step S1, and uniformly stirring to obtain a mixed solution;

s3, dropwise adding ammonia water into the mixed solution obtained in the step S2 while stirring, adjusting the pH value to 10-11, and then uniformly stirring to obtain a reaction solution;

s4, carrying out suction filtration and washing on the reaction liquid, drying at 120 ℃ for 12-24h, and roasting in a muffle furnace at 500 ℃ for 4-8h after drying to obtain the tin-titanium composite oxide;

s5, adding a proper amount of chloroplatinic acid solution prepared in the step S1 into the tin-titanium composite oxide, and stirring for 2-4 hours at room temperature to obtain a slurry-like mixture;

s6, drying the slurry mixture obtained in the step S5 at 120 ℃ for 12-24h, and then placing the dried slurry mixture into a muffle furnace to be roasted at 500 ℃ for 1h to finally obtain the tin-doped platinum-titanium catalyst.