Materials World Network: In-Situ Investigation of Model Multi-Component Catalyst Systems

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。这是马萨诸塞州理工学院（MIT-美国）和拜罗伊特大学（UB-德国）之间的联合项目。在过去的三十年里，催化剂在减少90%以上的汽车排放量方面发挥了核心作用，但进展在很大程度上被现象学的“试错”方法所减缓。因此，抑制了用于使用于车载诊断应用的催化剂的建模和优化合理化的手段。该项目旨在更好地了解催化剂材料的性质及其与基质和气体的相互作用。 这样的理解将推进催化剂科学，并提高催化剂的工程能力，以改善功能。这有可能影响广泛的商业战略行业，包括石化催化裂化，蒸汽重整，标准化学品（氨，硫酸）的合成，燃料电池电极，所有这些都依赖于非均相催化剂。鉴于对环境的关注，这项工作非常适合年轻学生，并在麻省理工学院现有水平的基础上扩大了K-12学生的推广计划。该计划是用来吸引本科生，并提供研究生在全球科学环境中工作的经验。应用跨学科的方法，利用多种表征工具，在现实的操作条件下，实现催化剂系统内的所有组分（载体，存储组件，贵金属）的行为和相互作用的详细知识。模型结构组成的贵金属，氧/氮氧化物的存储和支持材料集成在三层的安排，其特点是通过气相或溶液的方法沉积到氧化物衬底上的膜，允许系统控制的表面积，三相边界和扩散长度。通过微球模板化和喷墨印刷（MIT）实现表面积和受控的介孔和纳米孔。存储材料的缺陷化学和氧交换性能，被修改的固溶体形成/掺杂剂，通过库仑滴定，电子/离子电导率，复阻抗和晶体微量天平方法检查。此外，表面敏感测量，包括功函数（MIT），XPS和DRIFT（UB），在两个实验室中应用。差流反应器研究（UB）提供了所需的整体催化剂性能输入，而低热质量陶瓷微热板允许在汽车排气中经历的编程快速热偏移类型。开发和测试描述各种催化剂系统组分的相互作用的模型。模型系统的电响应作为研究工具和原位诊断催化剂性能的手段是有意义的。一个核心组成部分是学生和工作人员的广泛交流，提供学习新的实验和建模方法的机会，并深入了解如何从全球角度进行研究。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This is a joint project between the Massachusetts Institute of Technology (MIT- USA) and the University of Bayreuth (UB- Germany). Catalysts have played a central role in reducing automotive emissions by over 90% over the past three decades but progress is slowed by largely a phenomenological, "trial-and-error" approach. As a consequence, means for rationalizing the modeling and optimization of catalysts for on-board diagnosis applications has been inhibited. This project aims to obtain an improved understanding of the catalyst materials properties and their interactions with substrate and gases. Such understanding will advance the science of catalysts as well as improve the ability to engineer catalysts towards improved functionality. This has the potential for impacting a broad range of commercially strategic industries including petrochemical catalytic cracking, steam-reforming, synthesis of standard chemicals (ammonia, sulfuric acid), & fuel cell electrodes, all of which depend on heterogeneous catalysts. Given the focus on environment, this work is ideally suited for young students and an outreach program for K-12 students is expanded under this program from present levels at MIT. The program is used to attract undergraduates and to provide graduate students experience working in a global scientific environment.An interdisciplinary approach is applied which utilizes multiple characterization tools, under realistic operating conditions, to achieve a detailed knowledge of the behavior and interplay of all the components within the catalyst system (support, storage component, noble metal). Model structures composed of noble metal, oxygen/NOx storage and support materials are integrated in three-layer arrangements featuring films deposited by vapor or solution methods onto oxide substrates allowing for systematic control of surface area, triple phase boundary and diffusion lengths. Surface area and controlled meso- and nano-porosity are achieved by microsphere templating and ink-jet printing (MIT). The defect chemistry and oxygen exchange properties of the storage materials, to be modified by solid solution formation/dopants, is examined by coulometric titration, electronic/ionic conductivity, complex impedance and crystal microbalance methods. Additionally, surface sensitive measurements, including work function (MIT), XPS and DRIFT (UB), are applied in the two laboratories. Differential flow reactor studies (UB) provide needed overall catalyst performance input, while low thermal mass ceramic micro hot-plates allow for programmed rapid thermal excursions of the type experienced in automotive exhausts. Models describing the interactions of the various catalyst system components are developed and tested. The electrical response of the model system is of interest as an investigative tool and as a means of diagnosing catalyst performance in situ. A central component is the extensive exchange of students and staff providing opportunities to learn new experimental and modeling methods and to gain insight into how research is approached from a global perspective.