WO2022126843A1 - 三元 NiO 纳米片 @ 双金属 CeCuOx 微片核壳结构复合材料及其制备与应用 - Google Patents

三元 NiO 纳米片 @ 双金属 CeCuOx 微片核壳结构复合材料及其制备与应用 Download PDF

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WO2022126843A1
WO2022126843A1 PCT/CN2021/074577 CN2021074577W WO2022126843A1 WO 2022126843 A1 WO2022126843 A1 WO 2022126843A1 CN 2021074577 W CN2021074577 W CN 2021074577W WO 2022126843 A1 WO2022126843 A1 WO 2022126843A1
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core
cecuo
composite material
microsheet
shell structure
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French (fr)
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路建美
陈冬赟
蒋军
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苏州大学
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Priority to US18/011,173 priority Critical patent/US20230241590A1/en
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Definitions

  • the invention relates to the technical field of nanocomposite materials, in particular to the preparation of a NiO nanosheet@bimetal CeCuOx microsheet core-shell structure composite material and its application in the thermal catalytic treatment of toluene.
  • VOCs Volatile organic compounds with boiling points between room temperature and 260°C are considered to be a major contributor to global air pollution, especially driven by environmental pollution such as ozone, photochemical smog, and secondary aerosols caused by toluene.
  • Environmental pollution such as ozone, photochemical smog, and secondary aerosols caused by toluene.
  • Low-temperature catalytic oxidation technology is considered as an effective and economical method to remove toluene, which has attracted extensive attention.
  • transition metal oxide catalysts are much cheaper. They are viable and sufficiently active in some reactions. In order to achieve the purpose of developing alternative precious metal catalysts and lowering the reaction temperature, it is necessary to conduct research on multi-element transition metal oxide catalysts. As typical transition metal oxides, CeO 2 , NiO and CuO have the advantages of low cost and high thermal stability. Therefore, in view of the current situation, it is necessary to develop an effective method to prepare new multi-component composite catalysts.
  • the purpose of the present invention is to provide a preparation method of NiO nanosheet @ bimetallic CeCuO x microsheet core-shell structure composite material, using the method of water bath thermal reaction, the NiO nanosheet is grown on the bimetallic CeCuO x microsheet to achieve low temperature
  • gaseous pollutants such as toluene gas.
  • the present invention adopts the following specific technical scheme: ternary NiO nanosheet @ bimetallic CeCuO x microsheet core-shell structure composite material, the preparation method thereof includes the following steps: (1) cerium salt, copper salt, organic acid , after the solvent is mixed, a solvothermal reaction is performed, and then the reaction product is calcined to obtain CeCuO x microchips.
  • the cerium salt is hexahydrate cerium nitrate
  • the copper salt is copper nitrate trihydrate
  • the solvent is DMF (N,N-dimethylformamide)
  • the nickel salt is nickel nitrate
  • in the alcohol/water mixed solvent the alcohol is Ethanol, preferably the volume ratio of alcohol and water is 1:1.
  • the weight of the NiO nanosheet is 1-5 times the weight of the bimetal CeCuO x microsheet, such as NiO nanosheet, bimetal CeCuO x
  • the weight ratio of microchips is 1:1, 3:1, 5:1.
  • the temperature of dissolving in the solvent is room temperature, and the time is 2 to 3 hours; the solvothermal reaction is carried out in an autoclave, the reaction temperature is 80 ° C to 90 ° C, and the time is 24 to 25 hours, preferably, the reaction The temperature is 80 °C and the time is 24 h; the calcination is carried out in the air, the temperature is 350 °C ⁇ 400 °C, and the time is 4 ⁇ 4.5 hours, preferably, the calcination temperature is 350 °C, and the heating rate during calcination is 3 °C/min , the time is 4 hours.
  • the temperature of the water bath reaction is 80°C to 90°C, and the time is 1.5 to 3 hours, preferably 2 hours at 80°C;
  • the calcination temperature is 350°C, the heating rate during calcination is 3°C/min, and the time is 4 hours.
  • step (1) the molar ratio of cerium salt, copper salt and terephthalic acid is 2:(1.0-1.1):(4.0-4.1); in step (2), the molar ratio of nickel salt and urea is The ratio is 1:(5.0 ⁇ 5.1); the nickel salt is Ni(NO 3 ) 2 .
  • a bimetallic metal-organic framework is used as a catalyst precursor to prepare a binary metal oxide catalyst (CeCuO x ) with excellent activity.
  • CeCuO x has a large specific surface area, good stability, and a large The specific surface area can promote the catalytic performance and is a good catalyst material.
  • the nickel oxide nanosheets are grown on the surface of CeCuO x by low temperature hydrothermal and heat treatment methods, and yNiO/CeCuO x with different ratios are prepared by adjusting the mass ratio of NiO/CeCuO x added.
  • CeCuOx core-shell composite catalyst The morphology composed of NiO nanosheets grown on bimetallic CeCuOx microsheets further increases the contact area, increases the active sites for catalysis, and shows excellent catalytic effect, which is efficient and economical.
  • the quantitative NiO nanosheet@bimetal CeCuOx microsheet core-shell structure composite material is put into an environment with a certain concentration of toluene, and a fixed bed reactor is used to heat and catalyze it, so as to realize low-temperature catalytic oxidation of toluene Using GCMS-QP2020 test, complete catalytic oxidation of toluene.
  • the invention further discloses the application of the above-mentioned negative NiO nanosheet@bimetal CeCuOx microsheet core-shell structure composite material in low-temperature catalytic oxidation of toluene.
  • the above-mentioned NiO nanosheet@bimetal CeCuOx microsheet core-shell structure composite material is placed in an environment containing toluene, and a fixed bed reactor is used to complete the treatment of toluene.
  • the temperature of low temperature complete catalytic oxidation of toluene gas is 210 °C.
  • NiO nanosheet@bimetal CeCuOx microsheet core-shell structure composite material disclosed in the present invention has a large specific surface area, a uniform pore size, and a controllable structure; the growth of nickel oxide increases the carrier The oxygen vacancies and contact area of the supported catalysts significantly improved the catalytic performance of the supported catalysts; the nanosheets were uniformly grown on the bimetallic CeCuO x microsheets to form a core-shell structure, and the larger specific surface area could promote the catalytic performance and increase the reactive sites. , is a good multi-element transition metal catalyst material.
  • the preparation method of the NiO nanosheet@bimetal CeCuOx microsheet core-shell structure composite material disclosed in the present invention the use of the precious metal particle load is avoided, the cost of the material is greatly reduced, and the nickel oxide grows to the CeCuOx On micro- and nano-sheets, the experimental process is relatively simple, and the catalytic performance of toluene is excellent, so it has high economical practicability and research value.
  • Figure 1 is a scanning electron microscope (SEM) image of the CeCuO x microchip.
  • Figure 2 is a transmission electron microscope (TEM) image of the CeCuO x microchip.
  • Figure 3 is a scanning electron microscope (SEM) image of the 3Ni/CeCuO x core-shell structure composite.
  • Figure 4 is a transmission electron microscope (TEM) image of the 3Ni/CeCuO x core-shell structure composite.
  • Figure 5 is a graph showing the thermocatalytic effect of NiO nanosheets@bimetal CeCuO x microsheet core-shell composites on toluene gas.
  • the preparation method of the NiO nanosheet@bimetal CeCuOx microsheet core-shell structure composite material disclosed in the present invention is as follows: (1) cerium salt, copper salt, and terephthalic acid (H 2 BDC) are respectively dissolved in a solvent and then mixed , and put it into an autoclave for solvothermal reaction, and then through centrifugal washing, drying, and calcining to obtain CeCuO x microchips.
  • cerium salt, copper salt, and terephthalic acid (H 2 BDC) are respectively dissolved in a solvent and then mixed , and put it into an autoclave for solvothermal reaction, and then through centrifugal washing, drying, and calcining to obtain CeCuO x microchips.
  • the raw materials used in the present invention are all conventional commercial products, and the specific operation method and testing method are conventional methods in the field.
  • Example 1 Preparation of CeCuO x microchips, the specific steps are as follows: at room temperature, Ce(NO 3 ) 3 ⁇ 6H 2 O (0.868 g, 2 mmol) and Cu(NO 3 ) 2 ⁇ 3H 2 O (0.242 g , 1 mmol) was dissolved in DMF (40 ml) and stirred at 1000 rpm for 2 h; H2BDC (0.664 g, 4 mmol) was dissolved in DMF (40 ml) and stirred at 1000 rpm for 2 h. The two solutions were then mixed with ultrapure water (20 ml) in a stainless steel autoclave and subjected to solvothermal synthesis at 80 °C for 24 h.
  • Example 2 Preparation of ternary NiO nanosheet @ bimetallic CeCuO x microsheet core-shell structure composite material, the specific steps are as follows: Calculate the feeding ratio with the mass of nickel oxide 3 times that of CeCuO x , and use the molar ratio of 1:5 Ni (NO 3 ) 2 and urea were dissolved in a 100 mL solution with a water/alcohol volume ratio of 1/1, then, 100 mg of the prepared CeCuO x microflake powder (Example 1) was added, and the resulting solution was stirred under conventional stirring. Placed at 80 °C for 2 hours.
  • the product powder was filtered and washed, then dried at 90 °C, and then calcined at 350 °C under an air atmosphere for 4 h at a heating rate of 3 °C/min to obtain ternary NiO nanosheets@bimetal CeCuO x microsheet core-shell
  • the structural composite material named 3Ni/CeCuO x (indicating that the weight ratio of NiO nanosheets and bimetallic CeCuO x microsheets is 3:1 based on the feeding ratio), was then subjected to performance and characterization tests.
  • FIG. 4 is a SEM image of the 3Ni/CeCuO x composite material
  • FIG. 5 is a TEM image of the 3Ni/CeCuO x composite material. It can be seen from the figure that the nickel oxide was successfully grown on the CeCuO x microchip, and the distribution was very uniform.
  • Ni/ CeCuOx and 5Ni/ CeCuOx were obtained, which were named Ni/ CeCuOx and 5Ni/ CeCuOx respectively.
  • Example 3 Ternary NiO nanosheets@bimetal CeCuOx microsheet core-shell composites
  • the thermal catalysis conditions for toluene gas are: the toluene concentration is 50 ppm (air is used as the filling gas, purchased from Messer Air Liquide Co., Ltd. ), the amount of the catalyst was 50 mg, according to the conventional method, the catalyst was fixed on the fixed bed reactor through a U-shaped tube, and the catalytic effect of the composite material on toluene gas under heating conditions was analyzed by gas chromatography, and the test condition was 36000 ml/(h ⁇ g).
  • FIG. 5 is a graph showing the thermal catalysis effect of ternary NiO nanosheet@bimetal CeCuOx microsheet core-shell structure composite on toluene gas. It can be seen from Fig. 5 that the present invention can be applied to the conversion of toluene at a lower temperature.
  • Toluene pollution in the air mainly comes from building materials, interior decoration materials, daily life and office supplies, outdoor industrial waste gas, automobile exhaust, photochemical smog, etc.
  • the specific catalytic effect of toluene is analyzed by gas chromatography.
  • the calculation method of toluene conversion rate is as follows Equation (1): .
  • C0 and C are the initial and test concentrations of toluene in the experiment (tested every 15 minutes), respectively.
  • Example 2 The solvothermal synthesis at 80 °C for 24 hours in Example 1 was adjusted to solvothermal synthesis at 80 °C for 48 hours, and the rest remained unchanged.
  • the obtained CeCuO x microchips were prepared according to the method of Example 2, and 3Ni/CeCuO was prepared x , the same toluene conversion test was carried out, and the toluene gas could not be completely catalytically oxidized at 210 °C, that is, the conversion rate was less than 100%.
  • Example 2 The heating rate of 3 °C/min in Example 1 was adjusted to a heating rate of 10 °C/min, and the rest remained unchanged.
  • the obtained CeCuO x microchips were prepared according to the method of Example 2, and 3Ni/CeCuO x was prepared, and the same toluene conversion test was carried out, The conversion was less than 95% at 210°C.
  • Example 2 The 350 °C in Example 2 was adjusted to 400 °C, and the rest remained unchanged to prepare 3Ni/CeCuO x , and the same toluene conversion test was carried out, and the conversion rate was less than 92% at 210 °C.
  • the above analysis shows that the nickel oxide nanosheets can be successfully grown on CeCuO x microsheets to form a core-shell structure composite material using the technical solution of the present invention, the process is simple and feasible, and the growth of nickel oxide is very uniform, and a certain proportion of the composite material Toluene has relatively good catalytic activity.
  • NiO nanosheets@bimetal CeCuO x microsheet core-shell structure composites have large specific surface area, uniform pore size, and controllable structure; the growth of nickel oxide increases the oxygen vacancies and contact area of the carrier, which significantly improves the Catalytic performance of supported catalysts; nanosheets are uniformly grown on bimetallic CeCuO x microsheets to form a core-shell structure, the larger specific surface area can promote the catalytic performance and increase the reactive sites, it is a good multivariate transition metal type At the same time, the load of precious metal particles is avoided, and the cost of materials is greatly reduced.
  • the experimental process is relatively simple, and the catalytic performance of toluene is excellent. Therefore, the catalyst of the invention further achieves the purpose of economical practicability.

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Abstract

提供三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料及其制备方法与应用。CeCuO x具备较大的比表面积,良好的稳定性,通过低温水热和热处理方法生长氧化镍纳米片于CeCuO x表面,制备NiO/CeCuO x核壳结构复合材料催化剂。双金属CeCuO x微片相比于单金属氧化物氧化铜和氧化铈对甲苯的催化表现出较优异的性能,进一步的生长不同浓度的氧化镍纳米片有效提高了催化活性,其中3Ni/CeCuO x催化剂可在210℃实现甲苯的完全催化。

Description

三元NiO纳米片@双金属CeCuOx微片核壳结构复合材料及其制备与应用 技术领域
本发明涉及纳米复合材料技术领域,具体涉及一种NiO纳米片@双金属CeCuO x微片核壳结构复合材料的制备及其在甲苯热催化处理中的应用。
背景技术
沸点在室温至260℃之间的挥发性有机化合物(VOC)被认为是造成全球空气污染的主要因素,尤其是在甲苯造成的臭氧,光化学烟雾和二次气溶胶等环境污染的驱使下,人们倡导使用有效的技术来减少对环境和人类健康的损害。低温催化氧化技术被认为是去除甲苯的一种有效而经济的方法,引起了人们的广泛关注。
近年来,许多科学家在研发更高效的、能在更低温度下催化氧化VOC的催化剂方面做出了很大的努力。一般而言,用于总VOC氧化的高效催化剂有两种类型,它们分别是负载的贵金属和过渡金属氧化物。虽然贵金属基催化剂被认为是用于VOC催化氧化的较好催化剂而备受关注。但是,它具有热稳定性差和成本高,高表面能易团聚的缺点。因此,正在努力设计不同的多元过渡金属氧化物纳米结构催化剂,例如核壳结构和具有高表面积的中空多孔材料。
与昂贵且稀有的贵金属相比,过渡金属氧化物催化剂便宜得多。在一些反应中它们是可行的和充分活跃的。为了达到开发替代贵金属催化剂和降低反应温度的目的,进行多元过渡金属氧化物催化剂的研究是很有必要的。作为典型的过渡金属氧化物,CeO 2、NiO和CuO具有低成本、高热稳定性的优点。因此,针对现状,很有必要研发一种有效的方法来制备新型多元复合材料催化剂。
技术问题
本发明的目的是提供一种NiO纳米片@双金属CeCuO x微片核壳结构复合材料的制备方法,采用水浴热反应的方法,将NiO纳米片生长到双金属CeCuO x微片上,以实现低温高效处理气体污染物,比如甲苯气体的目的。
技术解决方案
为了达到上述目的,本发明采用如下具体技术方案:三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料,其制备方法包括以下步骤:(1)将铈盐、铜盐、有机酸、溶剂混合后进行溶剂热反应,然后煅烧反应产物,得到CeCuO x微片。
(2)将镍盐、尿素、所述CeCuO x微片的混合物在醇/水混合溶剂中进行水浴反应,然后煅烧反应产物,得到三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料。
具体的:(1)将铈盐、铜盐、对苯二甲酸分别在溶剂中溶解后混合,再放入高压反应釜中进行溶剂热反应,反应产物经离心洗涤、干燥、煅烧处理后得到CeCuO x微片。
(2)将镍盐和尿素溶于乙醇和水的混合液中,再加入CeCuO x粉末进行水浴反应,反应产物经离心洗涤、干燥、煅烧处理后得到三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料。
本发明中,铈盐为六水合硝酸铈,铜盐为三水合硝酸铜;溶剂为DMF(N,N-二甲基甲酰胺);镍盐为硝酸镍;醇/水混合溶剂中,醇为乙醇,优选醇、水的体积比为1∶1。
优选的,三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料中,NiO纳米片的重量为双金属CeCuO x微片重量的1~5倍,比如NiO纳米片、双金属CeCuO x微片的重量比为1:1、3:1、5:1。
本发明中,在溶剂中溶解的温度为室温,时间为2~3小时;溶剂热反应在高压反应釜中进行,反应温度为80℃~90℃、时间为24~25小时,优选的,反应温度为80 ℃,时间为24 h;煅烧在空气中进行,温度为350℃~400℃、时间为4~4.5小时,优选的,煅烧的温度为350℃,煅烧时升温速率为3 ℃/min,时间为4小时。
本发明中,水浴反应的温度为80℃~90℃,时间为1.5~3小时,优选80℃反应2小时;煅烧在空气中进行,温度为350℃~400℃、时间为4~4.5小时,优选的,煅烧的温度为350℃,煅烧时升温速率为3 ℃/min,时间为4小时。
本发明中,步骤(1)中,铈盐、铜盐、对苯二甲酸的摩尔比为2∶(1.0~1.1)∶(4.0~4.1);步骤(2)中,镍盐和尿素的摩尔比为1:(5.0~5.1);镍盐为Ni(NO 32
本发明首先采用以双金属金属-有机骨架作为催化剂前体来制备具有出色活性的二元金属氧化物催化剂(CeCuO x),CeCuO x具备较大的比表面积,良好的稳定性,而较大的比表面积可以促进催化性能,是一种良好的催化剂材料;再通过低温水热和热处理方法生长氧化镍纳米片于CeCuO x表面,通过调节NiO/CeCuO x加入的质量比,制备不同比值的yNiO/CeCuO x核壳结构复合材料催化剂。由NiO纳米片生长在双金属CeCuOx微片构成的形貌,进一步增大了接触面积,增加了催化的活性位点,且显示优异的催化效果,高效经济。
本发明在煅烧处理后,将定量NiO纳米片@双金属CeCuO x微片核壳结构复合材料放入具有一定浓度甲苯环境中去,利用固定床反应器对其进行加热催化,实现低温催化氧化甲苯利用GCMS-QP2020测试,完全催化氧化甲苯。
本发明进一步公开了上述负NiO纳米片@双金属CeCuO x微片核壳结构复合材料在低温催化氧化甲苯中的应用。
本发明公开的低温热催化处理甲苯的方法中,将上述NiO纳米片@双金属CeCuO x微片核壳结构复合材料置入含有甲苯的环境中,利用固定床反应器完成甲苯的处理,优选的,低温完全催化氧化甲苯气体的温度为210 ℃。
有益效果
本发明的优点:1、本发明公开的NiO纳米片@双金属CeCuO x微片核壳结构复合材料具有较大的比表面积、均一的孔径大小、可控的结构;氧化镍的生长增加了载体的氧空位和接触面积,明显提升了载体催化剂的催化性能;纳米片状均一地生长在双金属CeCuO x微片上构成核壳结构,较大的比表面积可以促进催化性能,增加了反应活性位点,是一种良好的多元过渡金属型催化剂材料。
2、本发明公开的NiO纳米片@双金属CeCuO x微片核壳结构复合材料的制备方法中,避免了使用贵金属颗粒的负载,极大的降低了材料的成本,并且氧化镍生长到CeCuO x微片纳米片上,该实验流程较简单,对甲苯的催化性能较优异,因此具有较高的经济实用性和研究价值。
附图说明
图1为CeCuO x微片的扫描电镜图(SEM)。
图2为CeCuO x微片的透射电镜图(TEM)。
图3为3Ni/CeCuO x核壳结构复合材料的扫描电镜图(SEM)。
图4为3Ni/CeCuO x核壳结构复合材料的透射电镜图(TEM)。
图5为NiO纳米片@双金属CeCuO x微片核壳结构复合材料对甲苯气体的热催化效果曲线图。
本发明的实施方式
本发明公开的NiO纳米片@双金属CeCuO x微片核壳结构复合材料的制备方法如下:(1)将铈盐和铜盐,对苯二甲酸(H 2BDC)分别在溶剂中溶解后混合,并放入高压反应釜中进行溶剂热反应,再经离心洗涤、干燥、煅烧处理后得到CeCuO x微片。
(2)将镍盐和尿素溶于乙醇和水的混合液中,再加入CeCuO x粉末进行水浴反应,再经离心洗涤、干燥、煅烧处理后得到NiO纳米片@双金属CeCuO x微片核壳结构复合材料。
本发明所用原料都为常规市售产品,具体操作方法以及测试方法为本领域常规方法。
实施例一:CeCuO x微片的制备,具体步骤如下:室温下,将Ce(NO 33·6H 2O(0.868 g,2 mmol)和Cu(NO 32·3H 2O(0.242 g,1 mmol)溶解在DMF(40 ml)中,并在1000 rpm下搅拌2 h;将H 2BDC(0.664g,4mmol)溶解在DMF(40ml)中,并以1000 rpm搅拌2 h。然后将两种溶液在不锈钢高压釜中与超纯水(20 ml)混合,在80 ℃下进行溶剂热合成24小时,将获得的蓝色沉淀CeCuBDC用DMF和乙醇冲洗几次,然后在65 °C下真空干燥6 h,接着在空气中将CeCuBDC于350°C下煅烧4 h,3 ℃/min升温速率由室温升至350℃,得到CeCuO x微片。附图1为CeCuO x微片的SEM图,附图2为CeCuO x微片的TEM图;从图中可以看出微片的二维层状结构,且为平行四边形的规整形貌。
实施例二:三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料的制备,具体步骤如下:以氧化镍3倍于CeCuO x质量计算投料比,将摩尔比为1∶5的Ni(NO 32和尿素溶解于水/醇体积比为1/1的100mL溶液中,然后,加入100mg制备好的CeCuO x微片粉末(实施例一),并将得到的溶液在常规搅拌下置于80 ℃下2反应小时。将产物粉末过滤并洗涤,然后在90 ℃下干燥,接着在空气气氛下于350℃,以3 ℃/min升温速率进行4 h煅烧,得到三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料,命名为3Ni/CeCuO x(表示按投料比计,NiO纳米片、双金属CeCuO x微片的重量比为3∶1),再进行性能和表征测试。
附图4为3Ni/CeCuO x复合材料的SEM图,附图5为3Ni/CeCuO x复合材料的TEM图。从图中可以看出氧化镍成功生长到了CeCuO x微片上,且分布很均一。
将Ni(NO 32的投料量改变,得到NiO纳米片、双金属CeCuO x微片的重量比为1:1、5:1的复合材料,分别命名为Ni/CeCuO x、5Ni/CeCuO x
实施例三:三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料对甲苯气体的热催化条件是:甲苯浓度为50 ppm(空气作为填充气,购买于梅塞尔液化空气有限公司),催化剂的量为 50 mg,根据常规方法,将该催化剂通过U形管固定在固定床反应器上,通过气相色谱分析该复合材料在加热条件下对甲苯气体的催化效果,测试条件为36000 ml/(h∙g)。
附图5为三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料对甲苯气体的热催化效果曲线图。由附图5可知,本发明可应用于较低温度下甲苯的转化。空气中甲苯污染主要来源于建筑材料、室内装饰材料和生活及办公用品,室外的工业废气、汽车尾气、光化学烟雾等,具体的甲苯催化效果是通过气相色谱分析的,甲苯转化率的计算方法如方程(1):
Figure 748974dest_path_image001
C 0和C分别为实验中甲苯的初始浓度和测试浓度(每15分钟测试一次)。
通过图5效果对比可知,具备大片状形貌的双金属CeCuO x样品的催化性能明显优于单金属的CeO 2和CuO样品,证实了该双金属样品形貌结构的优势。此外,生长氧化镍到CeCuO x微片上,进一步提高氧空位的浓度,促使催化性能明显提高,且氧化镍的均匀生长又使其催化性能大大提高,并且避免了使用贵金属。因此,3Ni/CeCuO x复合材料催化剂相对既经济又高效。
比较例:将实施例一中80 ℃下进行溶剂热合成24小时调整为80 ℃下进行溶剂热合成48小时,其余不变,得到的CeCuO x微片根据实施例二的方法,制备3Ni/CeCuO x,进行同样的甲苯转化测试,在210 ℃下无法完全催化氧化甲苯气体,即转化率不到100%。
将实施例一中3 ℃/min升温速率调整为10 ℃/min升温速率,其余不变,得到的CeCuO x微片根据实施例二的方法,制备3Ni/CeCuO x,进行同样的甲苯转化测试,在210℃下转化率不到95%。
将实施例二中350 ℃调整为400 ℃,其余不变,制备3Ni/CeCuO x,进行同样的甲苯转化测试,在210 ℃下转化率不到92%。
对比例:将摩尔比为1∶5的的Ni(NO 32和尿素溶解于水/醇体积比为1/1的100mL溶液中,然后,将得到的溶液在常规搅拌下置于80 ℃下2反应小时,然后在90 ℃下干燥,接着在空气气氛下于350 ℃,以3 ℃/min升温速率进行4 h煅烧,得到固体材料,进行同样的甲苯转化测试,在210 ℃下转化率不到30%。
通过以上分析,说明采用本发明的技术方案氧化镍纳米片可以成功生长到CeCuO x微片上构成核壳结构复合材料,工艺简单易行,且氧化镍的生长非常均匀,且一定比例的复合材料对甲苯具有相对较好的催化活性。NiO纳米片@双金属CeCuO x微片核壳结构复合材料,具有较大的比表面积、均一的孔径大小、可控的结构;氧化镍的生长增加了载体的氧空位和接触面积,明显提升了载体催化剂的催化性能;纳米片状均一地生长在双金属CeCuO x微片上构成核壳结构,较大的比表面积可以促进催化性能,增加了反应活性位点,是一种良好的多元过渡金属型催化剂材料;同时避免了使用贵金属颗粒的负载,极大的降低了材料的成本,该实验流程较简单,对甲苯的催化性能较优异,因此,此发明的催化剂进一步实现了经济实用性的目的。

Claims (10)

  1. 一种三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料,其特征在于,所述三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料的制备方法包括以下步骤:
    (1)将铈盐、铜盐、有机酸、溶剂混合后进行溶剂热反应,然后煅烧反应产物,得到CeCuO x微片;
    (2)将镍盐、尿素、所述CeCuO x微片的混合物在醇/水混合溶剂中进行水浴反应,然后煅烧反应产物,得到三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料。
  2. 根据权利要求1所述三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料,其特征在于:步骤(1)中,铈盐、铜盐、有机酸的摩尔比为2∶(1.0~1.1)∶(4.0~4.1);溶剂为DMF;有机酸为对苯二甲酸。
  3. 根据权利要求1所述三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料,其特征在于:以Ce(NO 33·6H 2O、Cu(NO 32·3H 2O为原料,在对苯二甲酸存在下,制备CeCuO x微片。
  4. 根据权利要求1所述三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料,其特征在于:步骤(2)中,镍盐和尿素的摩尔比为1:(5.0~5.1);镍盐为Ni(NO 32
  5. 根据权利要求1所述三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料,其特征在于:三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料中,NiO纳米片的重量为双金属CeCuO x微片重量的1~5倍。
  6. 权利要求1所述三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料的制备方法,其特征在于包括以下步骤:
    (1)将铈盐、铜盐、有机酸、溶剂混合后进行溶剂热反应,然后煅烧反应产物,得到CeCuO x微片;
    (2)将镍盐、尿素、所述CeCuO x微片的混合物在醇/水混合溶剂中进行水浴反应,然后煅烧反应产物,得到三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料。
  7. 根据权利要求6所述三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料的制备方法,其特征在于:步骤(1)中,溶剂热反应的温度为80℃~90℃、时间为24~25小时;煅烧在空气中进行,温度为350℃~400℃、时间为4~4.5小时。
  8. 根据权利要求6所述三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料的制备方法,其特征在于,步骤(2)中,水浴反应的温度为80℃~90℃、时间为2~2.5小时;煅烧在空气中进行,温度为350℃~400℃、时间为4~4.5小时。
  9. 权利要求1所述三元NiO纳米片@双金属CeCuO x微片核壳结构复合材料在低温热催化处理气体污染物中的应用。
  10. 根据权利要求9所述的应用,其特征在于,气体污染物为甲苯。
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