Enhancement of catalytic properties of interlayer-expanded zeolite Al-MWW via the control of interlayer silylation conditions

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• 作者：Satoshi Inagaki^a ; Hiroyuki Imai^b ; Sho Tsujiuchi^b ; Hikaru Yakushiji^b ; Toshiyuki Yokoi^b ; Takashi Tatsumi^b ; ^{ttatsumi@cat.res.titech.ac.jp}
• 关键词：MWW-type zeolite ; Interlayer silylation ; Dealumination ; 12-Membered ring micropore
• 刊名：Microporous and Mesoporous Materials
• 出版年：2011
• 出版时间：June 2011
• 年：2011
• 卷：142
• 期：1
• 页码：354-362
• 全文大小：569 K

文摘

Treatment of the zeolitic layered precursor of Al-MWW, so-called Al-MWW(P), with diethoxydimethylsilane (DEDMS) in 1.0 M HNO₃ media gave an aluminosilicate-type interlayer-expanded zeolite MWW (Al-IEZ-MWW) with expanded 12-membered ring (12-MR) micropores. By the interlayer-silylation of Al-MWW(P), the micropore diameter of interlayers with 12-MR supercages enlarged from ca. 7.0 to ca. 8.0 Å, verifying the formation of the interlayer-expanded structure. The interlayer-silylation of Al-MWW(P) under the acidic conditions with 1.0 M HNO₃ caused the penetration of DEDMS molecules into the interlayers, resulting in the formation of monomeric silica puncheons between the MWW layers. Whereas the interlayer-silylation of Al-MWW(P) by using 1.0 M HNO₃ caused remarkable dealumination of the MWW framework, the “two-step” silylation, namely, the first silylation in 0.1 M HNO₃ and the following silylation in 1.0 M NH₃, gave Al-IEZ-MWW retaining most of framework Al. The obtained Al-IEZ-MWW showed a high catalytic activity in the Friedel–Crafts acylation of anisole with acetic anhydride compared to Al-MWW as well as zeolite beta, suggesting that Al-IEZ-MWW is a useful candidate as a solid acid catalyst for the acylation reactions and other acid-catalyzed reaction of bulky molecules.