title: Synthesis and structural characterization of Al-containing interlayer-expanded-MWW zeolite with high catalytic performance.
abstract: Treatment of the zeolitic layered precursor of Al-MWW, so-called Al-MWW(P), with diethoxydimethylsilane (DEDMS) in acidic media leads to the formation of an aluminosilicate-type interlayer-expanded zeolite MWW (Al-IEZ-MWW) with expanded 12-membered ring (12-MR) micropores. However, the silylation process under acidic conditions simultaneously causes dealumination from the MWW framework, resulting in a decrease in the acid amount. We have developed a method for preparing Al-IEZ-MWW without leaching of the Al species. The strategy is to conduct the silylation under weakly acidic conditions; the silylation was conducted in an aqueous solution of an ammonium salt, e.g., NH4Cl, instead of HNO3. Subsequent additional acid treatment led to the formation of Al-IEZ-MWW that shows a high catalytic performance in the acylation of anisole compared to typical Al-MWW as well as Al-IEZ-MWW directly prepared under acidic conditions. The change in the state of Al atoms during the preparation process was investigated by high-resolution solid-state (27)Al MAS NMR and (27)Al MQMAS NMR techniques.
authors.affiliation: Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan. yokoi.t.ab@m.titech.ac.jp.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yokoi
authors.forename: Shun
authors.initials: S
authors.lastname: Mizuno
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Imai
authors.forename: Takashi
authors.initials: T
authors.lastname: Tatsumi