Synthesis and characterization of hollow zeolite microspheres with a mesoporous shell by O/W/O emulsion and vapor-phase transport method

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• 作者：Jifang Cheng ; Supeng Pei ; Bin Yue ; Linping Qian ; Chunxia He ; Yan Zhou ; Heyong He
• 关键词：Hollow sphere ; O/W/O emulsion ; Vapor-phase transport ; Zeolite ; ZSM-5
• 刊名：Microporous and Mesoporous Materials
• 出版年：2008
• 出版时间：1 November 2008
• 年：2008
• 卷：115
• 期：3
• 页码：383-388
• 全文大小：1248 K

文摘

Hollow microspheres of ZSM-5 with a mesoporous shell have been synthesized through formation of amorphous hollow SiO₂/Al₂O₃ microspheres by sol–gel process in multiple oil–water–oil emulsions and transformation of the amorphous species into zeolite by water–organic vapor-phase transport treatment at 160 °C for 8 days. The morphology of the amorphous and zeolite spheres observed by scanning electron microscopy shows no significant change whereas the molar ratio of Si/Al increases from 6 to 20 during the transformation. The structural feature of zeolite was characterized by X-ray diffraction and ²⁹Si and ²⁷Al magic-angle spinning nuclear magnetic resonance. Transmission electron microscopy and N₂ adsorption–desorption isotherms indicate that uniform mesopores in the shell of zeolite spheres arise from the interstices among zeolite crystallites.