State Key Laboratory of Fine Chemicals, Department of Catalysis Chemistry and Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning, China.
Phys Chem Chem Phys. 2011 Jun 21;13(23):11248-53. doi: 10.1039/c1cp20185a. Epub 2011 May 6.
The effect of zeolite Y precursor on the formation of MCM-41 containing zeolite Y building units has been investigated by means of UV Raman spectroscopy, X-ray diffraction (XRD), infrared spectroscopy (IR) and electron microscopy (SEM and TEM). Study of the precursor formation shows that 4-membered ring species are formed at the early stages of crystallization. Zeolite Y begins to appear after crystallization for 4 h, and its crystallinity increases with increasing crystallization time. However, lowering the pH value to ∼9.3 in the second step not only facilitates the polymerization of silicate species, but also leads to the structural change of the precursors. Pure MCM-41 mesoporous phase containing zeolite Y building units and the mixture of zeolite Y and MCM-41 can be formed combining the effects of the precursor structure and the pH adjustment.
采用紫外拉曼光谱、X 射线衍射（XRD）、红外光谱（IR）和电子显微镜（SEM 和 TEM）研究了沸石 Y 前体对含沸石 Y 结构单元的 MCM-41 形成的影响。前体形成的研究表明，在结晶的早期形成四元环物种。沸石 Y 在结晶 4 小时后开始出现，其结晶度随结晶时间的增加而增加。然而，将第二阶段的 pH 值降低到约 9.3 不仅有利于硅酸盐物种的聚合，而且还导致前体的结构发生变化。通过结合前体结构和 pH 值调节的影响，可以形成含有沸石 Y 结构单元的纯 MCM-41 介孔相和沸石 Y 与 MCM-41 的混合物。
