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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/5863

    Title: 應用固態核磁共振方法鑑定Mordenite沸石脫鋁反應後的酸性
    Authors: 葉明珠;Ming-Zhu Ye
    Contributors: 化學研究所
    Keywords: 固態和磁共振儀;脫鋁反應;沸石;探測分子;三甲基磷;三烷基磷氧化物;NMR;Dealumination;Probe molecules
    Date: 2001-07-16
    Issue Date: 2009-09-22 10:09:01 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 沸石(Zeolite)一直被廣泛的應用於許多工業應用及異相觸媒催化反應中,但是對於沸石結構中的路易士酸(Lewis acid site)及布忍司特酸(Brfnsted acid site),仍然存在著許多問題,尤其是steamed後的沸石。所以要了解沸石的結構及組成在催化反應中的影響,首先必須先確定酸性位置分佈及其大小。 沸石可經各種不同的修飾法來改變骨架結構或組織,以改善其對反應的催化活性。其中脫鋁反應屬於最常被使用的一種方法,所以吾人嘗試利用酸萃取法與矽取代法對沸石進行骨架結構或組織改變,以尋求更好的催化活性。 本研究主要是利用探測分子-三甲基磷(Trimethylphosphine簡稱為TMP) 及三烷基磷氧化物(Trimethylphosphine oxide簡稱為TMPO),將其吸附於H-MOR沸石及脫鋁後的樣品,並利用魔角旋轉固態核磁共振儀,觀測1H、29Si、27Al及31P等核種之核磁共振訊號,對H-MOR沸石及脫鋁後的樣品中的酸性位置分佈及大小加以探討。 Despite the widespread use of zeolites in many industrial processes, there still remain many unanswered questions as tot he nature of the Lewis and Bronsted acid sites, particularly in steamed samples. A full characterization of the structure and acidity of these acid sites is essential if an understanding of the effect of composition and structure on the catalytic properties of the material is to be obtained. The composition such as Si/Al ratio of zeolites can be modified through different methods to improve the activity and selectivity of these materials in heterogeneous catalysis. Dealumination of zeolites is one of the methods that is most widely used. Therefore, acid leaching and subsequent chemical agent (with (NH4)2SiF6) treatments have been employed to dealuminate H-mordenite for seeking the best catalytic activity. The purpose of this work is to characterize the dealuminated mordenite samples with multinuclear solid-state magic angle spinning (MAS) NMR, for example, 1H, 29Si, and 27Al NMR. Furthermore, the nature, type, and distribution of Bronsted and Lewis acid sites in dealuminated mordenite samples has been investigated by using trimethylphosphine (TMP) and trimethylphosphine oxide (TMPO) as 31P NMR probes.
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