Nanophase catalytic oxides: I. Synthesis of doped cerium oxides as oxygen storage promoters

Doped CeO₂ materials were synthesized with the aim to improve the performance of CeO₂ as oxygen storage promoter in gas catalytic reactions. The coprecipitation method was used for the synthesis of fine oxalate precursors of high homogeneity and well defined composition. The chemical and morphological properties of both the coprecipitated oxalates and the calcined oxides were examined. The influence of doping of different metal cations into the CeO₂ structure on the oxygen storage capacity in particular was investigated. Some of the doped oxides Ce_0.9M_0.1 O_{2 − δ} (M = Ca, Nd, Pb, etc.) give an increased oxygen storage capacity, 20–40% higher than the undoped. Their redox activity also remarkably increased.