New oxygen storage material (pCP)

One of the technologies required to comply with emission regulations in various countries is technology to reduce nitrogen oxide (NOx) emissions. Focusing on the “NOx emission behavior” in the fluctuating oxygen concentration range of engine exhaust gas, Cataler developed a “new oxygen storage material” (pCP) with an expanded active region when the oxygen concentration fluctuates.

Material with expanded active region when oxygen concentration fluctuates

Conventional materials have the characteristics of rapid oxygen storage but low maximum oxygen storage capacity. As a result, when exhaust gas with a high oxygen concentration flows in, the atmosphere around the precious metal quickly becomes excessively oxygen-rich, immediately oxidizing the precious metal so that it becomes inactive, and making it impossible to purify NOx. A new oxygen storage material (pCP: persistent Ceria-Zirconia Pyrochlore type solid solution) jointly developed by Toyota Central R&D Labs., Toyota Motor Corporation, and Cataler has a "slow and high" oxygen storage capacity. By combining with other materials, it is possible to achieve the desired oxygen storage characteristics as a catalyst. This makes it possible to absorb oxygen over a long period of time, and the precious metal retains its active state without oxidizing (i.e., it can retain its metallic state), so NOx emissions can be significant reduced.

Conventional material

Fluorite structure

Ce and Zr are randomly arranged
Nano-sized primary particles