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γ型氧化铝纳米管的合成及NO催化分解性能研究

The Synthesis of γ-Alumina Nanotube and Study of NO Decomposition

【作者】 杨斌

【导师】 李瑞丰;

【作者基本信息】 太原理工大学 , 化学工艺, 2009, 硕士

【摘要】 氧化铝纳米管作为一种新型材料,由于其表面的电子结构和晶体结构发生了较大的变化,表现出纳米材料所特有的小尺寸效应、表面效应、量子效应以及宏观量子隧道效应等特殊性能,被广泛应用于电子、化工、医药、机械、航天航空、冶金等领域,特别有望在催化领域作为催化剂或载体得以应用并在催化领域带来新的活力与生机。本文以AlCl3·6H2O为铝源,十六烷基三甲基溴化铵(CTAB)为模板剂,在水热体系中通过控制反应温度与时间合成了γ-Al2O3纳米管,并采用X-射线衍射、氮吸附、透射电子显微镜对合成的纳米管进行表征。结果表明,经煅烧并用盐酸处理后,即可得具有高比表面积的γ-Al2O3纳米管。其后,以此为载体,通过等体积浸渍法制备出不同Cu含量的催化剂,考察了载体、氧气浓度、二氧化硫、反应条件等在NO催化分解中对催化性能的影响并对机理进行简要的分析。结果表明,当氧化铝纳米管表面负载Cu的量为7 %时为最佳,其催化性能随温度的升高而增强,并且在600℃达到最大;在低温时,纳米Cu-γ-Al2O3催化剂显示出比Al2O3催化剂更高的催化活性;少量的O2(0.25﹪)对纳米Cu-γ-Al2O3催化活性没有太大的影响,而当O2含量高于0.25﹪时催化剂的活性随着O2浓度的增加而迅速降低;当反应体系中通入SO2时,纳米Cu-γ-Al2O3显示出了一定的抗硫性能。总之,本文主要利用软模板法合成了具有高比表面积且半径较均一的氧化铝纳米管,并研究了负载Cu的催化剂在NO分解中的催化性能。研究结果在环境治理方面具有较大的现实意义,特别有望在脱硝反应中得以广泛的应用并带来新的希望。

【Abstract】 As a new kind of materials, owing to its large variations in surface-electronic structure and crystal texture, alumina nanotube shows special characteristics of nanophase materials,such as small-size effects,surface effects,quantum effects and macro quanta tunneling effects. Now, for its spectial characteristics,alumina nanotubes have been used in electron,chemical industry,medication,machine,space flight aviation, metallurgy . In the future, alumina nanotubes are expected to bring in new applications and hopes in many areas,especially as a catalyst or catalytica carrier.In this paper,γ-Al2O3 alumina nanotube was synthesized in hydrothermal system by using the AlCl3?6H2O as aluminous sources and the CTAB as templates. The controlling of reactive temperature and time is most important in the reactive process and it would directly effect the final structure of alumina nanotubes. Alumina nanotubes were characterized by the X-ray diffraction,the nitrogenadsorption and the transmission electron microscope and the results showed the preparedγ-Al2O3 alumina nanotube had large specific surface. Cu loaded catalyst was prepared by incipient wetness impregation of theγ-Al2O3 alumina nanotube with an aqueous solution of Cu(NO3)2. Then, we studied the influence of carrier and O2 concertration together with SO2 on the catalytic reduction of NO. The results are as following: catalyst, 7% Cu loaded on theγ-Al2O3 alumina nanotube, shows the highest activity among the different Cu content, and the activity increases with the temperature, reaches the light-off temperature at 600℃, and remains even at 650℃; small amount of oxygen (0.25%) causes little change on the activity, while dramastic decrease of activty is observed as arising oxygen concertration; in the presence of SO2, the catalyst still presents an activity to some extend.In the final process, copper loaded in the surface ofγ-Al2O3 alumina nanotube show high catalytic activity in catalytic decomposition of NO,especially in low-temperature conditions,and they are hoped to be used widely in denitration reaction and bring in great ecomomic benefits.

【关键词】 纳米材料纳米管氧化铝NO催化分解
【Key words】 nanophase materialsnanotubealuminaNO decompsition
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