【作者】 滕飞；

【导师】 熊国兴； 田志坚；

【作者基本信息】 中国科学院研究生院（大连化学物理研究所） ， 物理化学， 2005， 博士

【摘要】 本论文以微乳技术为核心合成手段, 以LaMg_xMn_1-xAl₁₁O₁₉ 和Ce_xBa_1-xMn_yAl₁₁O_z 六铝酸盐催化剂为主要研究对象,以廉价、无毒的无机盐为前驱物,结合超临界干燥技术,制备了高稳定性、高活性的纳米结构的甲烷燃烧催化剂;同时,组装、合成了核/壳型CdS/SiO₂ 纳米粒子及SiO₂ 空心球。并通过相应的物理、化学表征手段,研究了催化剂性能与制备条件之间的关系,深入研究了制备方法对最终材料的影响,得到如下一些结论:反相微乳合成技术,在纳米材料制备中具有独特的应用价值。通过控制或调节粒子的成核、生长过程,可以有效地控制一次粒子的形貌和尺寸,最终控制催化剂颗粒的形貌与大小;并可以显著地提高前驱体组分的混合均匀性,促进六铝酸盐相在较低的温度下结晶,有利于制备大比表面、高活性的催化剂。并进一步研究了低维材料的热稳定性。微乳液的微结构可以有效地控制前驱体颗粒的形貌;采用超临界干燥,颗粒的形貌可以得到有效地维持。与球形粒子比较,低维针状颗粒具有较高的抗烧结能力;通过控制催化剂的形貌,可以有效地改善催化剂的催化性能。在核/壳型CdS/SiO₂ 纳米粒子及SiO₂ 空心球合成中,利用反相微乳液组装技术,可以有效地控制粒子尺寸的均匀性,使粒子的粒径分布在较窄的范围内,可以制得单分散的纳米粒子。研究表明,通过晶种生长过程,改变反应物的加入量及加料次序等操作参数,可以容易地在界观范围内控制颗粒的尺寸。CdS/SiO₂ 复合颗粒上可以进一步引入其他官能团物质,制备新的功能性复合材料。更多还原

【Abstract】 Catalytic combustion is an environmentally friendly technology, which caneffectively reduce the emissions of CO and NOx. However, synthesis of the catalystswith excellent thermal stability and high activity is a challenge to the development ofthe technology.In this paper, the nanotructured hexaaluminate catalysts were synthesized by thereverse microemulsion method, using the nontoxic and inexpensive inorganic salts,instead of the alkoxides, as reactants. The samples were characterized byN₂-adsorption, transmission electron microscopy （TEM）, TGA-DTA, and X-raypowder diffraction （XRD）. Therefore, the preparation is environmental-friendly andlow-cost. The study shows that the catalyst morphology could be controlledeffectively by the microemulsion microstructure; the homogeneityof precursor couldbe enhanced greatly by the reverse microemulsion method and the supercriticaldrying method; the catalyst morphology has a significant influence on its activity.Compared with the spherical particles, the one-dimmensional nanorod has higherabilityresistant to sintering.In addition, the monodispersed CdS-SiO₂ core-shell particles and hollow silicaranging from nanometers （30¹00nm） to micrometers （1.5²μ） were prepared byreverse microemulsions. The particles were characterized by Selected area electrondiffraction（SAED）, Scanning electron microscope （SEM）, X-ray fluroscence （XRF）,etc. The study shows that the core size and shell thickness could be tuned simply bycontrolling the addition amount and the addition way of the reactants.更多还原