(96a) Solution Combustion Synthesis of Porous CeO2 Nanopowders: Reaction Mechanism and Physical Properties

Cerium (IV) oxide (CeO₂) is an important material owing to its wide applications in polishing, catalysis, fuel cells and oxygen sensors. For all these cases, controlled synthesis of porous CeO₂ nanopowders is important since its redox and transport characteristics depend on the physical properties such as particle size, surface area, pore size and pore size distribution. In this work, CeO₂ nanopowders were prepared by solution combustion synthesis (SCS), varying the SCS parameters in terms of precursor oxidizer (cerium nitrate hexahydrate and cerium ammonium nitrate), fuel (glycine and hydrous hydrazine) and fuel-to-oxidizer ratio (0.5–3). These parameters influence the combustion behavior and, in turn, the properties of the CeO₂ powders. Based on the experimental results, the combustion reaction mechanism, and the correlation between the SCS parameters and the resulting powder morphology and properties is discussed.