ceriumoxide

Cerium oxide, commonly referred to as ceria, is a chemical compound with the formula CeO2. It is a pale yellow-white solid that adopts a fluorite-type crystal structure. Ceria can exhibit non-stoichiometry, forming Ce3+ and oxygen vacancies, which gives it redox flexibility and a notable oxygen storage capacity.

The material has a Ce4+/Ce3+ redox couple that enables rapid uptake and release of lattice oxygen. This property underpins its catalytic performance in oxidation and reduction reactions and makes ceria a key component in many high-temperature catalysts. Doping with zirconium to form cerium–zirconium solid solutions (CeZrO2) enhances oxygen storage capacity, thermal stability, and resistance to sintering.

Applications include automotive three-way catalysts for exhaust treatment, industrial oxidation processes, and photocatalysis. Nanoscale ceria is used as a polishing powder for glass and optics due to its chemical reactivity and soft abrasive properties. Ceria-based materials also appear as pigments in ceramics and as UV-protective additives in certain formulations. In research, ceria nanoparticles are studied for catalytic, energy storage, and biomedical applications, aided by tunable shapes (rods, cubes, octahedra) and doped compositions.

Synthesis methods range from precipitation and hydrothermal routes to high-temperature solid-state synthesis, often starting from cerium salts or cerium oxide precursors. Commercial ceria is available in powders, pellets, and nanostructured forms. Safety considerations include dust irritation and inhalation hazards; handling requires appropriate controls.