Synthesis and characterization of nanostructured CeO2-ZrO2 material with improved low-temperature reducibility

By increasing the proportion of Ce (IV) in cerium precursor salt, the structural homogeneity and redox property of nanostructured Ce0.5Zr0.5O2 oxygen storage material (CZ) was dramatically improved. The primary mechanism behind the enhanced properties was discussed. First, STEM-EDS observed that increasing the proportion of Ce (IV) precursor could promote the homogeneity of Ce and Zr atoms in precipitates. This is beneficial to the incorporation of Zr into ceria lattices during calcination, thus the structural homogeneity of CZ was enhanced and stabilized by increasing Ce (IV) precursor, which was evidenced by X-ray diffraction (XRD) results in combination with Rietveld refinement. Moreover, an increased amount of defective structures were detected by Raman, which accelerate the lattice oxygen mobility. Consequently, the synthesized CZ material exhibited the excellent reducibility with high thermal stability, in terms of its low reduction temperature of 422 degrees C and high reduction rate of 60% even after calcination at 1000 degrees C for 3 h. Therefore, the oxidation degree of cerium precursor plays a key role in determining the structural homogeneity and reducibility of the final CZ material.