Towards the Next Level of Molecular Control in the Sol-Gel Preparation of Mixed Oxides

混合氧化物溶胶-凝胶制备中分子控制的新水平

• 批准号: 9522066
• 负责人: Edmond Ko
• 金额: $ 17万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-11-01 至 1998-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9522066&HistoricalAwards=false
• 关键词: Towards; Next; Level; Molecular; Control

ABSTRACT CTS-9522066 This project explores the use of sol-gel preparation of mixed oxides to achieve predictable structures or textures and to apply this to the synthesis of acid catalysts. Specifically, titania-silica and alumina-silica are studied; the silicon precursor has significantly slower reactivity and this permits prehydrolysis to be used as a tuning variable. By varying the prehydrolysis ratio, gel networks of various microstructures can be obtained. Characterization of the product properties may provide a correlation of homogeneity with acidity. Nitrogen adsorption, X-ray diffraction, thermal analysis, pyridine adsorption, and 1-butene isomerization are used to characterize the textural, structural, and catalytic properties of the mixed oxides. Alternative precursors such as double metal alkoxides and performed sols are also studied, as are mixed oxides prepared by coprecipitation. This effort should provide the means to design mixed oxides with specific properties. Although the procedures to be used are well established, little systematic work on how the variables involved affect product properties has been done. (In other words, mixed oxide preparation is more "art" than "science".) Although this effort looks at catalytic properties, if successful it would clearly be extendable to other applications using mixed oxides, such as optical waveguides. ***

摘要CTS-9522066 该项目探索使用溶胶-凝胶制备混合氧化物，以实现可预测的结构或纹理，并将其应用于酸催化剂的合成。 具体而言，二氧化钛-二氧化硅和氧化铝-二氧化硅进行了研究;硅前体具有显着较慢的反应性，这允许预水解被用作调谐变量。 通过改变预水解率，可以得到不同微观结构的凝胶网络。 产品特性的表征可以提供均匀性与酸度的相关性。 氮吸附，X-射线衍射，热分析，吡啶吸附，和1-丁烯异构化被用来表征的纹理，结构和催化性能的混合氧化物。 替代前体，如双金属醇盐和执行溶胶也进行了研究，是通过共沉淀制备的混合氧化物。 这一努力应该提供设计具有特定性能的混合氧化物的方法。 虽然所使用的程序已经很好地建立起来，但关于所涉及的变量如何影响产品性能的系统工作却很少。 (In换句话说，混合氧化物的制备是“艺术”多于“科学”。 虽然这项努力着眼于催化性能，但如果成功，它显然可以扩展到使用混合氧化物的其他应用，如光波导。 ***