Syngas Production by Partial Oxidation of Methane with Oxygen Permeable Membrane

近年来，干凝胶转化法作为沸石的结晶技术得到了发展。本文研究了传统水热合成法和新型干凝胶转化法合成的不同类型沸石的结晶机理。我们不仅在原子尺度上，而且在纳米尺度上特别关注铝硅酸盐物种。水热合成mfi型沸石时，当铝硅酸盐的溶解度较低时，可以明显看出mfi型沸石是由直径为几十纳米的纳米颗粒聚集而成。此外，硅石-1可能是由非晶态纳米颗粒直接向微细mfi型晶体的固-固转变形成的。在使用干凝胶转化法合成EMT型沸石的情况下，我们发现纳米颗粒融合，干凝胶表面重新排列，导致EMT晶体呈现明显的六边形形状。此外，由于我们提出ZSM-5分子筛碱性溶解滤液中存在具有模具骨架结构的铝硅酸盐物质，我们成功地利用ZSM-5分子筛碱性溶解滤液中的铝硅酸盐物质合成了由分子筛骨架结构引起的强酸性介孔材料。综上所述，我们研究了沸石的结晶机理，重点研究了纳米级结构物质，并利用具有纳米级沸石骨架结构的物质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.