Structure and Impact of Spatiotemporal State on Catalytic Surfaces

催化表面时空状态的结构和影响

• 批准号: 9222476
• 负责人: Dan Luss
• 金额: $ 30.65万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-12-15 至 1996-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9222476&HistoricalAwards=false
• 关键词: Structure; Impact; Spatiotemporal; State; Catalytic

A wide variety of spatiotemporal patterns exist in nature with a wide degree of complexity, from simple and regular to highly disordered structures. These structures show some order in the midst of complex nonlinear behavior. The coupling of chemical reactions and transport processes, such as diffusion or hydrodynamic convection, is known to lead to the formation of spatially organized distributions of reactive compounds. Analysis and prediction of pattern-formation in chemically reacting systems to date have been for homogeneous medium and there is lack of understanding if and in which way inhomogeneity of a medium will distort the patterns that exist in a uniform medium. This relates directly to the performance of commercial heterogeneous catalysts, which are inherently nonuniform. The answer has implications on the assessment of the impact of spatiotemporal patterns on the performance of catalysts. This research involves experimental, numerical and theoretical studies of the formation, evolution, characterization, and impact of spatial and spatiotemporal patterns on catalytic surfaces. The experiments will provide quantitative data about the dynamic features of the patterns on catalysts with simple and symmetric geometry in a well-controlled environment for several test reactions, and will provide important information on the impact (or lack of impact) of catalytic- surface inhomogeneity on the observed patterns. The experimental information will serve as a guide to theoretical- model development and modification and for determining parameter values. Numerical and theoretical studies will help direct and organize the experimental research and point out potentially interesting regions of experimentation and catalyst geometries, and guide the development of principles predicting pattern formation and its impact. The research should provide insight into the role and impact of spatiotemporal patterns on the performance of heterogeneous catalysts.

自然界中存在着各种各样的时空模式， 从简单、规则到高度复杂， 无序结构 这些结构显示出一定的秩序， 复杂的非线性行为。 的耦合 化学反应和运输过程，如扩散 或流体动力学对流，是已知的， 反应性化合物的空间组织分布。 化学成图分析与预测 迄今为止的反应体系是用于均相介质的， 缺乏理解，如果和以何种方式， 介质的不均匀性会扭曲现有的模式 在均匀的介质中。 这直接关系到性能 商业非均相催化剂，这是固有的 不均匀。 答案对评估 时空模式对性能的影响 催化剂的 本研究涉及实验、数值和理论三个方面 研究的形成，演变，表征，和 空间和时空格局对催化剂的影响 表面。 这些实验将提供定量数据 催化剂上的图案的动态特征， 在良好控制的环境中的简单和对称几何 几个测试反应，并将提供重要的 关于催化剂的影响（或缺乏影响）的信息， 表面不均匀性对观察到的图案。 的 实验信息将作为理论指导- 模型开发和修改以及确定 参数值。 数值和理论研究将有助于 指导和组织实验研究，指出 潜在的有趣的实验领域， 催化剂的几何形状，并指导原则的发展 预测模式的形成及其影响。 研究 应提供深入了解的作用和影响， 时空模式对异构 催化剂的