Atomic Level In Situ and Modeling Studies of Redox Processes in Ceria and Ceria Zirconia

清洁的空气对我们的健康至关重要，在减少污染方面取得了里程碑式的成就，在汽车排气系统中使用催化转化器使用了氧化铈-氧化锌材料。催化剂由纳米颗粒组成，这项研究将研究这些材料在使用时发生的结构和化学变化。环境透射电子显微镜的最新进展使在原位[接近反应堆或应用]条件下对结构和化学变化的原子水平观察成为可能。高分辨率电子显微镜中心具有独特的能力，可以检查不超过5-50纳米的单个颗粒的化学成分。计算技术的补充组合将用于了解温度和氧化/还原条件如何影响颗粒，包括对晶体结构、表面能、表面分离、表面扩散和烧结行为的影响。将在不同的环境中进行实验，以确定CeO2-ZrO2系统低温还原和储氧能力增强的原因。从这项研究中获得的信息将被用于开发改进的催化剂，从而潜在地减少汽车污染。几个优秀的教育计划已经到位，包括工业协会计划。将开发关于减少污染的教育模块，并针对来自劣势学校的中小学生。将提供暑期实习机会。

Clear air is vital for our health, and milestone achievements have been made in reducing pollution by using catalytic converters in automobile exhaust systems which incorporate ceria-zirconia materials. The catalysts are composed of nanometer-sized particles, and this research will investigate the structural and chemical changes that occur when these materials are in use. Recent advances in environmental transmission electron microscopy have made it possible to make atomic level observations of the structural and chemical changes under in situ [close to reactor or application] conditions. Unique capabilities exist at the Center for High Resolution Electron Microscopy which allow the chemistry of individual particles that are no larger than 5-50 nanometers to be examined. A complementary combination of computational techniques will be used to understand how temperature and oxidizing/reducing conditions affect the particles, including the effect on crystal structure, surface energy, surface segregations, surface diffusion, and sintering behavior. Experiments will be performed in various environments to identify the reasons for enhanced low temperature reduction and oxygen storage capacity for ceria-zirconia systems. The information obtained from this research will be used to develop improved catalysts leading to potential reductions in automobile pollution. Several excellent educational programs are in place, including an Industrial Associates Program. Educational modules on pollution abatement will be developed and targeted to elementary and high school students from less advantaged schools. Summer internships will be available.