金、钯—介孔碳及聚乙炔修饰钯基MOFs材料的研究

发布时间：2018-03-03 09:35

  本文选题：纳米催化　切入点：有序介孔碳　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：催化剂是工业生产和科学研究的重要内容,对于纳米催化而言,催化剂的稳定性以及可接触性是影响其在各个催化体系应用的重要因素。从这两个角度出发,本文设计了两种新型负载型贵金属纳米催化剂,旨在得到稳定性良好、可接触性良好的模型催化剂。多孔碳是高温催化剂载体的优选对象,本文结合胶体纳米颗粒的组装工艺,通过组装多成分(氧化铁、贵金属)的三维有序胶体球,在惰性气氛下对胶体球进行碳化处理,胶体纳米颗粒单体表面的有机活性剂将原位地碳化成介孔的结构,再通过盐酸的选择性刻蚀作用除去氧化铁纳米颗粒,最终得到分散性良好的耐高温的负载型贵金属纳米催化剂。所制备的三维有序介孔碳具有1461.0653 m2·g-1超高比表面,介孔尺寸大小7.5 nm,为可以耐受1000℃的高温而不发生明显的结构坍缩现象;由于三维有序介孔碳的空间限域作用,所制备的金负载的三维有序介孔碳纳米催化剂能够经受800℃的高温而未发生明显的团聚现象,而良好的介孔结构同时保证了该负载型催化剂在催化反应体系中良好的可接触性;该设计路线同时适用于其他贵金属催化剂,如我们将之推广至钯基的负载型高温催化剂。用乙炔处理钯负载的ZIF-67表面,利用钯对乙炔良好的加聚作用,在其表面包覆了聚乙炔层。该疏水性的聚乙炔膜提高了钯催化剂的可接触性,同时也提高了 ZIF-67表面的水稳定性,经水的刻蚀作用最终得到空心结构的钯基负载型催化剂。聚乙炔膜的引入不仅使得催化剂的水稳定性极大提高,研究结果表明,本课题所制备的空心结构能够在沸水中稳定存在;同时在催化性能上也有明显的提升,表现为催化活性提升了近40%。
[Abstract]:Catalyst is an important content in industrial production and scientific research. For nanocatalysis, the stability and accessibility of catalyst are important factors affecting its application in various catalytic systems. In this paper, two new supported noble metal nanocatalysts are designed to obtain model catalysts with good stability and good contact. Porous carbon is the best choice object for high temperature catalyst support. In this paper, the assembly process of colloidal nanoparticles is combined. By assembling three-dimensional ordered colloidal spheres with multi-component (iron oxide, precious metal), the colloidal spheres were carbonized in inert atmosphere, and the organic active agents on the surface of colloidal nanoparticles carbonized in situ to form mesoporous structures. After selective etching of hydrochloric acid to remove the iron oxide nanoparticles, the supported noble metal nanocatalysts with good dispersion and high temperature resistance were obtained. The prepared three-dimensional ordered mesoporous carbon has 1461.0653 m2 路g-1 ultra-high specific surface. The mesoporous size is 7.5 nm, which can withstand high temperature at 1000 鈩，

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