Solid-State NMR Studies Of Ceria Nanomaterials

Nanomaterials often show improved catalytic properties than their bulk counterparts.The catalytic processes involving oxide nanomaterials are considered closely associated with the exposed facets which are determined by the morphology,oxygen vacancy,as well as the interfacial interactions.However,such structural details and structure property relationship are still not very clear.Solid-state NMR spectroscopy is a powerful tool with which to investigate the local structure of materials at atomic/molecular scale.By using 17O solid-state NMR spectroscopy,in combination with other characterization methods,this thesis focuses on the investigations of the surface structure of ceria nanostructures,which is the widely used,in particular in the field of water gas shift reaction and three-way catalysts.It is revealed that the chemical shifts of oxygen species on the surface of ceria nanostructures with different morphologies are different,while the oxygen sites at the metal-oxide interface in Au/CeO2 nanorods may be associated with distinct chemical shifts.These results form the basis for the deeper understanding of the surface structure and the structure properties relationship of ceria nanostructures,as well as the development of new spectroscopic methods for related problems.