Hierarchical zeolite : synthesis, characterization and catalytic application위계나노다공성 제올라이트 : 합성, 특성규명 및 촉매응용성 연구

Cited 0 time in webofscience Cited 0 time in scopus
  • Hit : 453
  • Download : 0
The work presented in this thesis addressed the synthesis, characterization and application of new type of zeolite materials possessing micro-/mesoporous structural hierarchy. Zeolite is a crystalline material possessing uniform micropores (0.3 < diameter < 2 nm) of molecular dimension. The molecular sieving ability of zeolite has enabled the creation of selective separation (ion exchange, sorption, etc.) and catalytic processes. In particular, zeolites with various structures constitute one of the most widely used classes of acid catalyst in industry. However, in many applications, slow diffusion into the microporous structure imposes a diffusion limitation on reaction rate. The diffusion limitation also accelerates coke formation at pore entrances, which significantly reduces catalytic activity and recyclibility of zeolite catalysts. To solve these problems, several attempts to synthesize zeolite with a large external surface area, hence with facile molecular diffusion into zeolite structure, were made in the past. In the present work, zeolites possessing tunable mesoporous structure were synthesized by adding a rationally designed amphiphilic organosilane surfactant into conventional alkaline zeolite synthesis mixtures. The zeolite products were rigorously characterized by a complementary combination of X-ray diffraction (XRD), $N_2$ adsorption, scanning and transmission electron microscopy. The analysis results reveal that the present method is suitable as a direct synthesis route to ‘hierarchical’ zeolites that contain secondary mesoporosity as well as the intrinsic zeolite microporosity. The mesopore diameters can be finely tailored, similar to the ordered mesoporous silicas having amorphous frameworks. The hierarchical zeolite exhibited a narrow, small-angle XRD peak, which is characteristic of the short-range correlation between mesopores, similar to disordered wormhole-like mesoporous materials. The synthesis of the crystalline aluminosilicate mater...
Advisors
Ryoo, Ryongresearcher유룡researcher
Description
한국과학기술원 : 화학과,
Publisher
한국과학기술원
Issue Date
2007
Identifier
263557/325007  / 020045270
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 화학과, 2007.2, [ xi, 98 p. ]

Keywords

mesoporous; herarchical; zeolite; 제올라이트; 메조기공; 위계나노다공성

URI
http://hdl.handle.net/10203/31680
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=263557&flag=dissertation
Appears in Collection
CH-Theses_Ph.D.(박사논문)
Files in This Item
There are no files associated with this item.

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0