【摘要】 以NaY沸石为原料,采用SiCl₄同晶取代脱铝技术,制得了硅铝比变化范围较宽的八面沸石,所得样品结晶度高且系列性好。用XRD测定沸石的晶相、晶胞参数α₀和峰相对强度,以IR测定沸石的骨架振动谱带。系统地研究了制备条件对脱铝产品性能的影响,并对取代过程的化学原理进行了探讨。更多还原

【Abstract】 Highly crystalline faujasite zeolites with different Si/Al ratios ranging from 2.62 (NaY, as starting material) to 150 were successfully obtained by the dealumination of NaY with silicon tetrachloride vapour. The samples were characterized by X-ray diffraction analysis and infrared spectra of their framework. The integrity of this series and the high crystallinity of these samples had not been reported in the literature. The effect of substitution conditions was systematically studied. It was found that the substitution temperature, duration, as well as the details of the after-treatment were of great importance for the successful preparation of these samples. The mechanism of SiCl4 vapour phase substitution is discussed, and the hypothesis of a two-step model is proposed.更多还原