Sayle Dean C, Maicaneanu S Andrada, Watson Graeme W
Department of Environmental and Ordnance Systems, Cranfield University, Royal Military College of Science, Shrivenham, Swindon, UK.
J Am Chem Soc. 2002 Sep 25;124(38):11429-39. doi: 10.1021/ja020657f.
Ceria is an important component in three-way catalysts for the treatment of automobile exhaust gases owing to its ability to store and release oxygen, a property known as the oxygen storage capacity. Much effort has been focused on increasing the OSC of ceria, and one avenue of exploration is the ability to fabricate CeO(2)-based catalysts, which expose reactive surfaces. Here we show how models for a polycrystalline CeO(2) thin film, which expose the (111), (110), and dipolar (100) surfaces, can be synthesized. This is achieved by supporting the CeO(2) thin film on an yttrium-stabilized zirconia substrate using a simulated amorphization and recrystallization strategy. In particular, the methodology generates models which reveal the atomistic structures present on the surface of the reactive faces and provides details of the grain-boundary structures, defects (vacancies, substitutionals, and clustering), and epitaxial relationships. Such models are an important first step in understanding the active sites at the surface of a catalytic material.
由于具有储存和释放氧气的能力(即所谓的储氧能力),二氧化铈是用于处理汽车尾气的三元催化剂中的重要成分。人们致力于提高二氧化铈的储氧能力,其中一个探索方向是制备具有活性表面的基于CeO₂的催化剂。在此,我们展示了如何合成暴露(111)、(110)和偶极(100)表面的多晶CeO₂薄膜模型。这是通过使用模拟非晶化和再结晶策略,将CeO₂薄膜支撑在钇稳定的氧化锆衬底上来实现的。特别是,该方法生成的模型揭示了活性面表面存在的原子结构,并提供了晶界结构、缺陷(空位、替代原子和聚集)以及外延关系的细节。此类模型是理解催化材料表面活性位点的重要第一步。