Influences of Si/Al Ratios on the Mesopore Distributions of Hierarchical MFI Zeolites Synthesized by Organosilane Surfactant

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• 作者：Lili Yu ; Shengjun Huang ; Shu Miao ; Xiangxue Zhu ; Shuang Zhang ; Zhenni Liu ; Wenjie Xin ; Sujuan Xie ; Longya Xu
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：January 15, 2014
• 年：2014
• 卷：53
• 期：2
• 页码：693-700
• 全文大小：493K
• ISSN：1520-5045

文摘

The silicon/aluminum ratio is proved to be a key parameter for mesoporosity tuning in the synthesis of hierarchical MFI zeolites by organosilane surfactant. At the fixed synthesis temperature, the mesopore size distribution evolves from a bimodal type to a uniform mode with the increase of Si/Al ratios. Moreover, different Si/Al ratios result in opposite responses of mesopore distributions to the elevation of synthesis temperature. With the elevated temperature from 140 to 150 掳C, the mesopore distribution of low-silica MFI zeolites (Si/Al_gel = 20) evolves from a bimodal type (centered at 4 and 10 nm) to a relatively uniform mode (centered at 8 nm), whereas the high-silica samples (Si/Al_gel = 40) exhibit a reverse transformation from a uniform mesopore distribution (centered at 3 nm) to a bimodal mode (centered at 4 and 20 nm). This work demonstrates alternative methods for the mesoporosity tuning of organosilane-directed hierarchical zeolites.