Controlled synthesis of nanocrystalline CeO2 and Ce1-xMxO2-δ (M = Zr, Y, Ti, Pr and Fe) solid solutions by the hydrothermal method: Structure and oxygen storage capacity

CeO2 and Ce1-xMxO2-delta (M = Zr, Ti, Pr, Y and Fe) nanocrystallites of 5-10 nm sizes have been synthesized by hydrothermal method using diethylenetriamine (DETA) and melamine as complexing agents. Compounds have been characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray analysis (EDX) and their structures have been refined by the Rietveld method. All the compounds crystallize in cubic fluorite structure. Even up to 50% Zr and Y, 40% Ti, 25% Pr and 15% Fe is Substituted for Ce4+ in CeO2 by this method. Sizes of crystallites can be tuned by changing the complexing agent and reaction temperature. Nanocrystalline CeO2 and Ce1-xZrxO2 prepared here have higher or at least competitive oxygen storage capacity (OSC) than those reported in literature. Ce1-xFexO2-delta shows higher OSC and higher percentage of CO oxidation at lower temperature than Ce1-xZrxO2. (C) 2008 Elsevier Inc. All rights reserved.