The Local Structure of Zeolites from X-Ray and Neutron Scattering Data

根据 X 射线和中子散射数据得出沸石的局部结构

• 批准号: 0085036
• 负责人: Raul Lobo
• 金额: $ 24万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0085036&HistoricalAwards=false
• 关键词: Local; Structure; Zeolites; Ray; Neutron

CTS-0085036Raul F. LoboUniversity of Delaware"The Local Structure of Zeolites from X-Ray and Neutron Scattering Data"ABSTRACTLike many useful materials, zeolites are often idealized as perfect crystals, solids inwhich periodic long-range order is observed in all three directions in space. Yet, very frequently the useful properties of a material stem from a small amount of minority elements (or defects) incorporated within the structure that shift the local environment away from the average. In this project the Pair Distribution Function (PDF), as derived from X-ray and neutron diffraction patterns, is being measured to investigate the local atomic environment in an important group of industrially significant zeolites. The gas-adsorption behavior and the catalytic activity of these porous materials are intrinsically associated with minor amounts of aluminum substituted for silicon in the structure. Since both catalysis and adsorption are fundamentally local phenomena, the understanding of zeolite properties thus depends on a detailed knowledge of the geometry of the sites. The research objective is to determine in detail the atomic geometry of these sites using the PDF.The results will help to explain the properties of various zeolites in their roles as catalysts and adsorbents. More detailed structure-property information will guide the design and synthesis of new, more effective materials with enhanced properties. The experimental structural data will also be valuable as a guide in the molecular modeling of zeolite properities.

CTS-0085036 Raul F. Lobo特拉华州大学“从X射线和中子散射数据分析沸石的局部结构“摘要与许多有用的材料一样，沸石通常被理想化为完美的晶体，在固体中，在空间的所有三个方向上都可以观察到周期性的长程有序。 然而，一种材料的有用特性往往源于结构中掺入的少量少数元素（或缺陷），这些元素使局部环境偏离平均水平。 在这个项目中，对分布函数（PDF），来自X射线和中子衍射图案，正在测量调查的本地原子环境中的一个重要的工业重要的沸石组。 这些多孔材料的气体吸附行为和催化活性本质上与结构中少量铝取代硅有关。由于催化和吸附从根本上来说都是局部现象，因此对沸石性质的理解取决于对位点几何形状的详细了解。 本研究的目的是利用PDF详细确定这些位置的原子几何结构，其结果将有助于解释各种沸石作为催化剂和吸附剂的性质。 更详细的结构-性能信息将指导设计和合成具有增强性能的新的、更有效的材料。 实验结构数据也将是有价值的指导分子模拟的沸石性质。