钯及金钯纳米晶的结构调控及其催化性能研究

发布时间：2018-05-13 22:13

本文选题：金属纳米晶体 + 光催化驱动　；参考：《辽宁大学》2017年硕士论文

【摘要】：金属纳米材料在催化等领域有着十分广泛的应用,因此成为目前材料学研究领域的热点之一。大量的研究结果已经表明,金属纳米催化剂在参与反应过程中的反应能量和反应速率主要依赖于纳米晶裸露的晶面,即尺寸以及形貌(晶面)是影响金属纳米材料性能的重要因素。目前,通过调控纳米晶尺寸和形貌(晶面)来进一步提高催化剂的催化性能、节约经济成本是科学研究的关键内容。在本文的工作中,以金和钯两种金属作为主要研究对象,采用简单普适的水相合成方法,通过设计金属纳米晶体的结构,使其在Suzuki碳碳偶联反应中展现良好的催化性能。将本论文主要工作内容概括如下:1.对金属纳米材料的生长理论、合成方法、双金属纳米晶的研究现状以及金和钯纳米晶已经取得的研究进展进行了简要介绍。2.对高活性纳米钯纳米晶的可控合成展开研究。利用晶种法,依靠卤素离子(Cl-,Br-,以及I-离子)对金属钯的{100}晶面的特异性吸附作用,合成了高指数{730}晶面裸露的内凹立方体钯纳米颗粒。以I-/O2为刻蚀剂,甲醛为还原剂,通过调节钯纳米颗粒的角、面、棱三个位点的刻蚀速率和生长速率,制备了框架结构钯纳米晶。3.通过外延生长的方式获得了核壳结构的金钯纳米晶,然后通过在氧化刻蚀的过程中同时引入还原过程,获得了一种具有独特形貌的双金属纳米晶,内部为八面体金纳米晶作为核、外部为框架结构钯纳米晶。相比于传统的核壳结构纳米晶,紫外-可见光吸收光谱显示框架结构钯纳米晶不影响八面体金核的光谱吸收。4.以Suzuki碳碳偶联反应为探针反应,以不同形貌纳米晶为催化剂进行了有机硼与卤代芳烃的偶联反应实验,验证了{730}晶面裸露的凹面体钯纳米颗粒以及框架结构钯纳米颗粒具有良好的催化能力以及稳定性。在光反应仪中进行的催化反应结果证明了独特结构的金钯双金属纳米晶能够在可见光照射下成功驱动碳碳偶联反应。
[Abstract]:Metal nanomaterials have been widely used in catalysis and other fields, so it has become one of the hotspots in the field of material research. A large number of research results have shown that the reaction energy and reaction rate of the metal nano catalyst in the reaction process depend mainly on the nanocrystalline crystal surface, that is, the size and morphology (crystal surface). It is an important factor affecting the properties of metal nanomaterials. At present, the key content of scientific research is to improve the catalytic performance of the catalyst and save the economic cost by controlling the size and morphology of nanocrystalline and morphology (crystal surface). In this paper, two metals of gold and palladium are used as the main research objects, and simple and universal water phase syntheses are used. Method, by designing the structure of metal nanocrystals to show good catalytic performance in the Suzuki carbon and carbon coupling reaction. The main contents of this paper are summarized as follows: 1. the growth theory of metal nanomaterials, the synthesis method, the research status of bimetallic nanocrystals and the progress of the gold and palladium nanocrystals have been simplified. The study of controllable synthesis of highly active nano palladium nanocrystals by.2. was introduced. By using the specific adsorption of halogen ions (Cl-, Br-, and I- ions) on the {100} crystal surface of metal palladium, the concave cubic palladium nanoparticles exposed to high index {730} crystal surface were synthesized by I-/O2 as a etching agent and formaldehyde as a reducing agent. The etching rate and growth rate of the angle, surface and prism of the palladium nanoparticles were obtained. The palladium nanocrystals of the palladium nanocrystalline.3. were prepared by the epitaxial growth of the palladium nanocrystalline.3.. Then the reduction process was introduced in the process of oxidation etching, and a kind of bimetallic nanocrystalline with unique morphology was obtained. The inner is the eight surface gold nanocrystals as the core and the external frame structure palladium nanocrystals. Compared to the traditional nuclear shell structure nanocrystals, the UV visible light absorption spectra show that the palladium nanocrystals in the framework structure do not affect the spectral absorption of the gold nuclei of the eight heals by the.4. carbon coupling reaction as the probe reaction, and the different morphology nanocrystals are used as the catalysts. The coupling reaction experiment between organic boron and halogenated aromatics shows that the palladium nanoparticles and the frame structure palladium nanoparticles have good catalytic ability and stability. The results of the catalytic reaction in the light reaction instrument show that the unique structure of gold palladium bimetallic nanocrystals can be irradiated by visible light. The carbon coupling reaction was successfully driven.

【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TB383.1

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