Oxygen Storage Capacity on Cerium Oxide - Precious Metal System

Cerium oxide (CeO₂) is known to have good oxygen storage capacity (OSC) and is used widely in three-way catalysts for automobiles, but it has a problem of inferior heat stability.

In our previous work, cerium-zirconiumyttrium (Ce Zr-Y) oxide systems were investigated with the aim of improving the heat stability of CeO₂-based oxide systems, and we found an optimum composition of Ce-Zr-Y oxide with platinum (Pt) showed good OSC even after high temperature aging.

In this study OSC and thermal stability of Ce-Zr-Y oxide with varying the types of precious metals were investigated to evaluate the effect of precious metals.

The results show that, Palladium (Pd) and Rhodium (Rh) are also available for Ce-Zr-Y oxide with precious metal system to improve OSC after thermal aging. In particular, Rh exhibited higher improvement than others at the composition of lower Ce content.