Zr-doped CeO_2 Hollow slightly-truncated nano-octahedrons: One-pot synthesis, characterization and their application in catalysis of CO oxidation

摘要

Zirconium-doped ceria hollow slightly-truncated nanooctahedrons (HTNOs) (Ce_(1-x)Zr_xO_2) were synthesized by a one-pot, facile hydrothermal method. The morphology and crystalline structure were characterized with powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and the high resolution transmission electron microscopy (HRTEM). The composition and chemical valence on the surface of the as-prepared Ce_(1-x)Zr_xO_2 powders were detected by X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometry (EDS). The surface area and pore size distribution of as-obtained Zr-doped ceria HTNOs were measured by N_2 adsorptiondesorption measurement. Mechanisms for the growth of Zr-doped ceria HTNOs are proposed as both oriented attachment and Ostwald ripening process and the formation of the hollow structure is strongly dependent on the addition of Zr~(4+) ions. Furthermore, the as-obtained Zr-doped ceria HTNOs revealed superior catalytic activity and thermal stability toward CO oxidation compared to pure ceria. It may provide a new path for the fabrication of inorganic hollow structures on introducing alien metal ions.