CAJ | 학술논문

在无有机模板剂体系中研究了不同硅铝比和晶粒度Beta沸石晶种的结构导向行为，采用X射线衍射、X射线荧光光谱、扫描电镜、透射电镜、紫外-拉曼光谱、红外光谱和N2物理吸附等方法对不同晶化时间固相产物和Beta沸石产物进行了表征。结果表明，不同Beta沸石晶种，包括全硅晶种，均能够导向合成Beta沸石，而且晶种在晶化诱导期都发生溶解。但是，晶种的硅铝比、晶粒度、预处理(焙烧)以及晶种加入的时间对晶种的溶解行为、Beta沸石晶化过程和产物都有重要影响。形貌研究还发现，含铝晶种不仅溶解后的残体通过提供晶核聚集的“固载化”表面导向了新生Beta沸石小晶体的密集生长，而且溶解下来的结构片段也提供了分散的晶核导向形成相对分散的Beta沸石小晶体；全硅晶种则仅通过溶解下来的结构片段提供分散的晶核。在无模板体系中，使用适当高硅铝比、小晶粒和经过焙烧处理的Beta沸石作为晶种有利于合成得到高结晶度的Beta沸石纯相。
재무유궤모판제체계중연구료불동규려비화정립도Beta비석정충적결구도향행위，채용X사선연사、X사선형광광보、소묘전경、투사전경、자외-랍만광보、홍외광보화N2물리흡부등방법대불동정화시간고상산물화Beta비석산물진행료표정。결과표명，불동Beta비석정충，포괄전규정충，균능구도향합성Beta비석，이차정충재정화유도기도발생용해。단시，정충적규려비、정립도、예처리(배소)이급정충가입적시간대정충적용해행위、Beta비석정화과정화산물도유중요영향。형모연구환발현，함려정충불부용해후적잔체통과제공정핵취집적“고재화”표면도향료신생Beta비석소정체적밀집생장，이차용해하래적결구편단야제공료분산적정핵도향형성상대분산적Beta비석소정체；전규정충칙부통과용해하래적결구편단제공분산적정핵。재무모판체계중，사용괄당고규려비、소정립화경과배소처리적Beta비석작위정충유리우합성득도고결정도적Beta비석순상。
The organic structure-directing agent-free synthesis of zeolite Beta was carried out using several zeolite Beta seeds that differed in SiO2/Al2O3 ratio and crystal size. The synthesis was studied using X-ray diffraction, X-ray fluorescence, scanning electron microscopy, transmission electron micros-copy, ultraviolet-Raman spectroscopy, infrared spectroscopy, and N2 physisorption. Synthesis was successful using different zeolite Beta seeds including pure silica seeds. During the induction period, the seeds underwent dissolution. The SiO2/Al2O3 ratio and crystal size, pretreatment (calcination), and seed addition time had a significant influence on seed dissolution behavior, crystallization pro-cess, and product. Morphological studies revealed that the seed residues produced by dissolution (except for pure silica) resulted in the formation of“immobilized”surface nuclei, which allowed for the dense growth of fresh small zeolite Beta crystals. The dissolved small seed fragments yielded dispersed nuclei, which formed relatively scattered small zeolite Beta crystals thought to be the main nuclei source of the pure silica seed. It is suggested that the use of an appropriately high SiO2/Al2O3 ratio, small size, and precalcined zeolite Beta seed is helpful for the synthesis of highly crystalline and pure zeolite Beta from the organic structure-directing agent-free gel.