High activity of amine-doped H-ZSM-5 zeolite in ethene protonation: revealed by embedding calculations.
High activity of amine-doped H-ZSM-5 zeolite in ethene protonation: revealed by embedding calculations.
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DOI：
10.1002/cphc.200600576
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发表时间：
2007-02
期刊：
影响因子：
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通讯作者：
Anmin Zheng;Lin Wang;Lei Chen;Y. Yue;C. Ye;Xin Lu;F. Deng
中科院分区：
文献类型：
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作者：
Anmin Zheng;Lin Wang;Lei Chen;Y. Yue;C. Ye;Xin Lu;F. Deng
沸石是结晶微孔铝硅酸盐，具有纳米尺寸的笼和通道的周期性排列。它们的结构、稳定性和高活性在工业中具有广泛的应用。[1]例如，沸石已被广泛用作烯烃质子化的催化剂，这是一种典型的酸碱双功能反应，是广泛的实验[2]和理论[3]研究的主题。沸石科学的一个里程碑式的发展是最近报道的新型有机-无机杂化沸石的合成，其中桥接氧原子的框架被CH2或NH基团部分取代。[4, 5]沸石的这种有机官能化扩大了它们的应用范围，并允许操纵控制与各种有机和无机客体物种相互作用的表面特性，[5]并且预计将成为卤代甲烷转化为碳氢化合物的潜在催化剂。[6]先前通过密度泛函理论研究了胺掺杂沸石中 NH 基团与甲醇、乙烯和氯甲烷的相互作用，使用两个簇模型，其中包含 n (n= 5, 16) 四面体 Si 或 Al 原子（表示为 5T 和 16T），且 NH 和 OH 跨越不同的 T 位点。 [6b] 对于胺取代沸石，NH 基团和 Brçnsted酸质子可能位于相同的四面体位置（“Si-NH-Al-OH-Si-”）。该构象通过魔角旋转 (MAS) NMR 实验证实存在于胺取代的 SAPO-11（一种 AEL 型分子）中
Zeolites are crystalline microporous aluminosilicates with periodic arrangements of cages and channels of nanometer dimensions. Their structure, stability and high activity have led to a broad variety of applications in industry.[1] For example, zeolites have been widely used as catalysts of olefin protonation, a typical acid-base bifunctional reaction that is the subject of extensive experimental [2] and theoretical [3] investigations. A landmark development in zeolite science is the recently reported synthesis of novel organic-inorganic hybrid zeolites, in which the framework bridging oxygen atoms are partially replaced by CH2 or NH groups.[4, 5] Such organic functionalization of zeolites widens the range of their applications and allows for the manipulation of the surface properties that control the interaction with various organic and inorganic guest species,[5] and are predicted to be potential catalysts in the conversion of halomethane to hydrocarbons.[6]The interaction of NH group in the amine-doped zeolites with methanol, ethene, and chloromethane were previously investigated by means of density functional theory using two cluster models that contain n (n= 5, 16) tetrahedral Si or Al atoms (denoted 5T and 16T) with ÀNHÀ and ÀOHÀ spanning at different T sites.[6b] For amine-substituted zeolites, NH group and Brçnsted acid proton may locate at the same tetrahedral sites (ÀSiÀNHÀAlÀOHÀSiÀ). This conformation was confirmed by the magic angle spinning (MAS) NMR experiment to be present in amine-substituted SAPO-11, an AEL type molecular