Optimization of Ceria-Zirconia Solid Solution based on OSC Measurement by Cyclic Heating Process

AbstractCeria is one of the rare earth metals having Oxygen Storage Capacity (OSC) characteristics, and it is widely used in Three- Way-Catalysts (TWC). Though Ceria has attractive properties, there are some inherent problems including limited OSC and thermal stability. In order to overcome the limitations of Ceria, an attempt is made to optimize the composition of CexZr1-xO2(0.4 ≤ x ≤ 0.8) (CZ) based on the OSC. The formation of homogenous solid solution, the lattice defect, cubic fluorite structureand OSC band of CZ were studied by suitable techniques. Thermogravimetric analysis was used to calculate the OSC of CZ solid solution with cyclic heating and cooling up to 800°C. It is concluded that OSC of CexZr1-xO2 was varied from 0.0435 to 0.1469μmol/gram of CeO2. Based on the highest OSC, Ce0.6Zr0.4O2 was confirmed to be a best solid solution among all the tested composition of CZ