RUI: Support Shape Effect in Metal-CeO2 Catalysis on Low-Temperature CO Oxidation

杨斯敦州立大学的王瑞刚教授是由化学系化学催化项目资助的，他的研究旨在帮助提高用于催化将危险一氧化碳排放转化为较少有害物质的系统的性能。这些催化转化系统由支撑在金属氧化物衬底上的微小金属颗粒组成，用于汽车尾气净化系统的一部分，但也用于气体传感器，燃料电池和其他有用的设备。小金属颗粒与氧化物衬底相互作用的性质，以及这两部分系统之间的接触面积，决定了催化转化器的选择性和活性。因此，本研究的目标是更深入、更详细地了解金属颗粒与氧化物衬底之间的接触如何影响催化作用，从而提高这些装置的性能。除了这项工作对社会使用技术产生更广泛的影响外，这项工作还对参与研究的一些本科生的教育经历产生了积极的影响。扬斯敦州立大学招收了很高比例的学生，这些学生来自传统上在科学领域代表性不足的群体，因此研究团队正在与该校的其他项目合作，让这些少数群体的学生参与到这个项目中来。由于研究团队中有来自周边地区的社区大学教师，这项研究正在产生进一步的影响。本项目的重点是阐明氧化铈（CeO2）载体的形状和大小对一氧化碳氧化的影响。目标是开发在低温下具有高氧化还原活性的稳定催化剂。颗粒形状，特别是晶体表面的晶面类型，被认为在铈基氧化物型氧化还原催化剂的表面还原性和催化活性中起着重要作用。初步研究结果表明，采用水热法和微波法可以制备出具有{110}、{100}、{211}等活性面的纳米棒、纳米管或纳米立方状的CeO2颗粒。在这个项目中，研究小组正在制备具有明确尺寸和形状的CeO2载体，并研究这些形状和大小如何影响模型催化反应，如一氧化碳氧化和水气转移反应。本研究的总体目标是开发一种预测模型，将不同的金属与不同的CeO2表面自然地联系起来，以获得优异的低温催化活性。通过开发这样一个预测模型，该项目有可能对许多实际应用的材料加工产生重大影响，如催化、燃料反应和气体传感，其中铈基氧化物的氧化还原功能起着至关重要的作用。

Professor Ruigang Wang of Youngstown State University is funded by the Chemical Catalysis Program of the Division of Chemistry for research to help improve the performance of systems used to catalyze the conversion of dangerous carbon monoxide emissions to less harmful substances. These catalytic conversion systems, composed of tiny particles of metal supported on a metal oxide substrate, are used in automobiles as part of the exhaust clean-up system, but also find application in gas sensors, fuel cells and other useful devices. The nature of the interaction of the small metal particles with the oxide substrate, as well as the contact area between these two parts of the system, determines how selective and active the catalytic convertor is. Therefore, the goal of this research is to develop a deeper and more detailed understanding of how contact between the metal particles and the oxide substrate affects the catalysis so that performance of these devices can be improved. In addition to the broader impact that this work is having on technology of use to society, the work is also positively affecting the educational experience of a number of undergraduate students involved in the research. Youngstown State enrolls a high percentage of students from groups that are traditionally under-represented in science, so the research team is working with other programs at the university to engage students from these minority groups in the project. The research is having a further impact by the inclusion of community college faculty from the surrounding region in the research team.This project focuses on elucidating the effect of the shape and size of cerium oxide (CeO2,) supports on carbon monoxide oxidation. The goal is to develop stable catalysts with high redox activity at low temperatures. Particle shape and, especially, the type of crystalline faces exposed on the surface of crystalites are believed to play a major role in surface reducibility and catalytic activity of cerium-based oxide type redox catalysts. Preliminary data obtained in a pilot study have shown that CeO2 particles shaped as nanorods, nanotubes, or nanocubes with reactive {110}, {100}, {211}, etc., faces on the crystal surface can be produced using hydrothermal and microwave methods. In this project, the research team is preparing CeO2 supports with well-defined sizes and shapes, and investigating how these shapes and sizes affect model catalytic reactions, such as carbon monoxide oxidation and the water-gas shift reaction. The overall goal of this research is to develop a predictive model that naturally links different metals with various CeO2 surfaces for a superior low-temperature catalytic activity. Through the development of such a predictive model, the project has the potential to have a major impact on materials processing for many practical applications such as catalysis, fuel reaction and gas sensing, where the redox functionality of cerium-based oxides plays a crucial role.