Structural and morphological properties of Ce(1-x)FexO2-δ synthesized by citrate route

Cerium-based materials were intensively studied in last years because of their high oxygen storage capacity (OSC) associated to the reversible Ce4+ <-> Ce3+ process and their properties closely related to the defect chemistry that could be adjusted by adequate selection of dopant. Fe3+ cation, due to its effective ionic radius smaller than that of Ce4+, is an interesting doping agent. In this work we present the synthesis and characterization of Ce(1-x)FexO2-delta mixed oxides (0 <= x <= 1) synthesized by the so named "citrate method". Our X-ray diffraction results suggest a rather strong dependence of lattice parameter on nanocrystal size, while Raman spectroscopy evidenced the formation of a small volume fraction of hematite clusters in samples with relatively high iron content, x >= 0.15, not observable in X-ray diffraction experiments. The solid solutions exhibit high porosity and specific surface area, with nearly 10% of pore volume in the micropore size range, making these materials potentially useful for applications in catalysis. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.