Jeong SY, Suh JK, Lee JM, Kwon OY
Applied Chemistry & Engineering Division, Korea Research Institute of Chemical Technology, Yusong, Taejon, 305-600, Korea
J Colloid Interface Sci. 1997 Aug 1;192(1):156-61. doi: 10.1006/jcis.1997.4974.
The silica-based mesoporous molecular sieves were synthesized from fluorosilicon compounds and Al, Ti with the hydrolysis reaction of H2SiF6 in an ammonia-surfactant mixed solution. Well-crystalline mesoporous molecular sieves were obtained after several hours at the atmospheric conditions. The solid products were characterized by X-ray powder diffraction, nitrogen adsorption/desorption, transmission electron microscopy and solid-state NMR spectroscopy. The solid products show high specific surface areas in the range of 627-1040 m2/g, depending on the amount of Al and Ti. Also, they exhibit narrow pore size distributions in the range of 31-35 A according to the addition of Al and Ti. 29Si MAS NMR indicate that all samples mainly contain Q4 types sites. Also, the peak intensity of Q3 sites decreases with increasing amount of aluminum. In 27Al MAS NMR spectra, all samples give intense lines from 4-coordinate aluminum. These results show that aluminum species are incorporated into the framework of Si-MMS. As the amount of Al increases, the intensity line from 6-coordinate aluminum increases. This result represents the increase of the fraction of amorphous aluminum species.
基于硅的介孔分子筛是由氟硅化合物与铝、钛在氨-表面活性剂混合溶液中通过六氟硅酸（H₂SiF₆）的水解反应合成的。在大气条件下经过数小时后获得了结晶良好的介孔分子筛。通过X射线粉末衍射、氮气吸附/脱附、透射电子显微镜和固态核磁共振光谱对固体产物进行了表征。根据铝和钛的含量，固体产物的比表面积在627 - 1040 m²/g范围内较高。此外，根据铝和钛的添加情况，它们的孔径分布在31 - 35 Å范围内较窄。²⁹Si MAS NMR表明所有样品主要含有Q₄型位点。而且，随着铝含量的增加，Q₃位点的峰强度降低。在²⁷Al MAS NMR光谱中，所有样品都给出了来自四配位铝的强峰。这些结果表明铝物种被掺入到硅-介孔分子筛的骨架中。随着铝含量的增加，来自六配位铝的强度线增加。这一结果代表了非晶态铝物种比例的增加。
