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论文类型：期刊论文

发表时间：2015-09-15

发表刊物：MICROPOROUS AND MESOPOROUS MATERIALS

收录刊物：SCIE、EI、Scopus

卷号：214

页面范围：204-209

ISSN号：1387-1811

关键字：Interlayer expansion; Zeolite; Lamellar precursor; COK-5; DCDMS

摘要：The layered silicate COK-5 has been used for an interlayer expansion reaction with dichlorodimethylsilane (DCDMS) at 180 degrees C to interconnect neighboring layers, yielding a new and crystalline microporous framework. The samples containing the methyl functional groups in the as-made form and having OH groups in the calcined form were designed as COE-5 and calcined COE-5. These samples were characterized with X-ray diffraction (XRD), N-2 sorption isotherms, inductively coupled plasma optical emission spectrometry (ICP-OES), infrared spectroscopy (IR), high-resolution transmission electron micrograph (HRTEM), thermogravimetry-differential thermal analysis (TG-DTA), and Si-29 and C-13 solid-state magic-angle spinning nuclear magnetic resonance (MAS NMR), as well as the contact angle techniques. XRD patterns and HRTEM images suggest that the sample interlayer spacing has been expanded by nearly 0.5 angstrom. The N-2 sorption isotherms of the materials show the BET surface areas are 165 m(2)/g for COE-5 and 340 m(2)/g for calcined COE-5. Si-29 and C-13 MAS NMR as well as IR spectroscopy confirm the insertion of the linker group -Si(CH3)(2)- connecting neighboring layers. Interestingly, calcined COE-5 shows enhanced catalytic performance in the acetalisation of glycerol with acetone to produce solketal, compared with COK-5. (C) 2015 Elsevier Inc. All rights reserved.