Syngas Production by Partial Oxidation of Methane with Oxygen Permeable Membrane

近年来，人们用水热合成法合成了沸石，发展了干凝胶转化法这一沸石晶化技术。本文研究了用常规水热合成法和新型干凝胶转化法合成的各种沸石的晶化机理。在水热合成MFI型沸石时，当铝硅酸盐物种的溶解度较低时，很明显，MFI型沸石是由直径几十纳米的纳米颗粒聚集而成的。在干凝胶转化法合成EMT型沸石的过程中，发现纳米颗粒熔融，干凝胶表面发生重排，形成了明显的六方晶形。此外，由于我们推测在ZSM-5的碱溶滤液中存在具有ZSM-5沸石骨架结构的硅酸铝物种，利用ZSM-5碱溶滤液中的铝硅酸盐物种，成功地合成了由沸石骨架结构引起的酸性较强的介孔材料。最后，研究了沸石的晶化机理，重点研究了纳米尺度上的结构物种，并利用具有沸石骨架结构的物种在纳米尺度上制备了新型酸性催化剂。

Zeolites have been synthesized by the hydrothermal synthetic method Recently, the dry gel conversion method as the technique of zeolite crystallization was developed. In this report, we investigated the crystallization mechanism of various type of zeolites synthesized by the conventional hydrothermal synthetic method and novel dry gel conversion method. We focus particularly on the aluminosilicate species in not only the atomic scale level, but also in a nano-scale level.In the case of the hydrothermal synthesis of MFI-type zeolite, when the solubility of aluminosilicate species was low, it was obvious that MFI-type zeolite consisted of aggregate of nano-particles in a diameter of several dozen nanometers. Moreover, it was possible that silicateli-1 was formed by the solid-solid transformation directly from amorphous nano-particles to fine MFI-type crystals.In the case of the synthesis of EMT-type zeolite by using the dry gel conversion method, we found out that nano-particles fuse and the surface of the dry gel is rearranged, resulting in a distinct hexagonal shape for the EMT crystals.Additionally, since we suggested that alinninosilicate species having die framework structure of ZSM-5 zeolite exist in the filtrate of alkaline dissolution of ZSM-5, we succeeded the mesoporous materials having a strong acidity caused by the structure of zeolite framework was synthesized by using the aluminosilicate species in the filtrate of alkaline dissolution of ZSM-5.In conclusion, we investigated the crystallization mechanism of zeolites, focusing on the structural species in a nano-scale level, and the novel acidic catalyst was prepared by using the species having the framework structure of zeolite in a nano-scale.