Yang Guoju, Qiu Ziyi, Peng Sainan, Nan Maiyan, Li Lin, Hou Ying, Chen Xiaoxin
State Key Laboratory of Inorganic Synthesis & Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun 130022, P. R. China.
Inorg Chem. 2022 Mar 28;61(12):4887-4894. doi: 10.1021/acs.inorgchem.1c03652. Epub 2022 Mar 14.
The development of nano-sized titanosilicate zeolites with hierarchical structures is crucial in promoting the efficient epoxidation of alkenes. In the present work, nano-sized hierarchical Ti-β () zeolites with high crystal yield are prepared by a one-pot nanoseed-assisted approach. The influence of seed size on the resultant Ti-β zeolites is investigated by complementary characterizations, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), N adsorption/desorption, UV-vis diffuse reflectance spectroscopy (DRS), and UV Raman spectroscopy. The possible process for the formation of hierarchical Ti-β nanocrystals with the assistance of nanoseeds in the synthesis gel is proposed. Consequentially, the nano-sized hierarchical material prepared by the nanoseed-assisted method shows excellent mass transportation and accessibility to active sites by reducing particle size and constructing hierarchical porosity, hence showing a remarkably enhanced catalytic activity and selectivity in the epoxidation reaction of alkenes. This work will shed light on the efficient preparation of nano-sized titanosilicate zeolites.
具有分级结构的纳米级钛硅沸石的开发对于促进烯烃的高效环氧化至关重要。在本工作中，通过一锅法纳米晶种辅助方法制备了具有高晶体产率的纳米级分级钛-β（）沸石。通过包括X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、傅里叶变换红外光谱（FT-IR）、N吸附/脱附、紫外可见漫反射光谱（DRS）和紫外拉曼光谱在内的互补表征，研究了晶种尺寸对所得钛-β沸石的影响。提出了在合成凝胶中借助纳米晶种形成分级钛-β纳米晶体的可能过程。因此，通过纳米晶种辅助方法制备的纳米级分级材料通过减小粒径和构建分级孔隙率，显示出优异的传质性能和对活性位点的可及性，从而在烯烃环氧化反应中表现出显著增强的催化活性和选择性。这项工作将为纳米级钛硅沸石的高效制备提供启示。
