Abstract：
　　Recent advances in nanomaterials synthesis make it possible to achieve nanocrystals with crystallographically defined surface facets, composition and high surface area, which can be considered as ideal model systems for catalytic studies under realistic conditions. In this work, I will showcase how we can make use of nanoshapes of binary oxide (ceria) and ternary oxide (SrTiO₃ perovskite) as model systems to gain molecular level understanding of the shape and composition effects on both the redox and acid-base properties and catalysis over these oxides. Catalytic insights are made possibly by investigating the atomic structure of the surfaces of these oxides as well as the interfaces between the oxides and metal particles via both in situ spectroscopy and advanced electron microscopy. The work manifests the importance of understanding both the surface atomic structure and composition for catalysis over both single and mixed oxide catalysts.