Guest/Host Interactions in High-Silica Zeolites

高硅沸石中的客体/主体相互作用

• 批准号: 9713516
• 负责人: Raul Lobo
• 金额: $ 25万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-15 至 2001-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9713516&HistoricalAwards=false
• 关键词: Guest; Host; Interactions; Silica; Zeolites

Prof. Raul F. Lobo will study the host-guest interactions of organic structure-directing agents in as-synthesized high-silica zeolites, in order to obtain correlations between organic structure and pore structure. The synthesis will evolve systematically from pure silica cathrasils to high-silica silica-alumina zeolites, utilizing various derivatized alkylammonium salt templates, and will affect cage and pore structures. Additionally, Prof. Lobo will investigate how to control the density and location of defect and Al3+ sites during the synthesis. Thermogravimetry will be used to measure internal volume. Multinuclear solid-state NMR experiments will be used to characterize the interaction, deuterium NMR to investigate the dynamic state of organic molecules as a function of temperature and molecule size, and NMR of other selected labels of the organic molecule to describe the molecule motion in several zeolite structures. Heteronuclear chemical shift correlation of 29Si and 1H will be used to obtain information on the molecular arrangement with respect to the location of tetrahedral Al3+ cations and zeolitic framework defects. To characterize the defects, also X-ray diffraction experiments will be done, for which 25 ? single crystals of pure ZSM-11 will be synthesized. The NMR experiments and in particular the spin-echo double resonance (SEDOR, 23Na{1H}) and rotational echo double resonance (REDOR, 29Si{23Na}) will be done to determine the spatial proximity of organic and inorganic components of the as-synthesized zeolite. The proposed research will help to improve the design and synthesis of zeolitic materials. This information will also be reflected in more accurate molecular mechanics and quantum mechanical models used for template selection and zeolite synthesis, and will improve the molecular simulation models of transport and diffusion in zeolites. Extrinsically, it will provide a stronger fundamental basis for the design of catalysts and molecular sieve separation materials with tailor ed pore structure and active site distribution. These chemically active materials support a major fraction of the chemical industry, including petrochemical, fuels, fine chemical, agrochemical, and others.

Raul F.教授Lobo将研究有机结构导向剂在合成高硅沸石中的主客体相互作用，以获得有机结构和孔结构之间的相关性。该合成将系统地从纯二氧化硅cathrasil发展到高硅氧化硅-氧化铝沸石，利用各种衍生的烷基铵盐模板，并将影响笼和孔结构。此外，Lobo教授将研究如何在合成过程中控制缺陷和Al 3+位点的密度和位置。将使用热重法测量内体积。多核固态NMR实验将被用来表征的相互作用，氘NMR研究的动态状态的有机分子作为温度和分子大小的函数，和NMR的其他选定的标签的有机分子描述的分子运动在几个沸石结构。 异序化学位移相关的29 Si和1H将被用来获得信息的分子排列相对于四面体Al 3+阳离子和沸石骨架缺陷的位置。为了表征缺陷，也将进行X射线衍射实验，其中25？将合成纯ZSM-11的单晶。将进行NMR实验，特别是自旋回波双共振（SEDOR，23 Na {1H}）和旋转回波双共振（REDOR，29 Si {23 Na}），以确定所合成的沸石的有机和无机组分的空间接近度。该研究将有助于改进沸石材料的设计和合成。这一信息也将反映在用于模板选择和沸石合成的更精确的分子力学和量子力学模型中，并将改进沸石中传输和扩散的分子模拟模型。此外，它将为设计具有特定艾德孔结构和活性中心分布的催化剂和分子筛分离材料提供更有力的基础依据。这些化学活性材料支持化学工业的主要部分，包括石化、燃料、精细化学品、农用化学品等。