Oxygen storage material, catalyst for cleaning exhaust gas, and method for manufacturing oxygen storage material

Oxygen storage material comprising oxide containing κ phase having large specific surface area

Overview

CeO₂-ZrO₂ composite oxide with excellent oxygen storage capacity (OSC) has been used as an atmosphere control material for ternary catalysts used to purify exhaust gas from automobiles. Among CeO₂-ZrO₂ composite oxides, κ phase (cubic pyrochlore like structure) is known to exhibit the highest OSC. However, due to the high temperature required for the synthesis process of κ phase, the specific surface area is significantly reduced and practical application of κ phase is difficult.　
In the present invention, it has become possible to provide an atmosphere-controlling material consisting of an oxide containing κ phase, in which the decrease in the specific surface area is greatly suppressed by the synthesis process at a lower temperature than in the conventional process. The low temperature is realized by adding Fe oxide during the synthesis of the complex oxide. The material by this synthesis process shows a clear XRD pattern assigned to the κ phase and has a specific surface area of 3 m²/g or more. This shows the possibility of practical application of the κ phase, and it can be said that the technology is expected to improve the purification ability of exhaust gas.

Ordering of cations

Product Application

・Exhaust gas purification

Related Works

[1] Kazuto Murakami, Yoko Sugawara, Junki Tomita, Akihiro Ishii, Itaru Oikawa and Hitoshi Takamura, J. Mater. Chem. A 2022,10, 21291-21299

IP Data

IP No.　 ： WO2023/048184 　
Inventor ： TAKAMURA Hitoshi, MURAKAMI Kazuhito
keyword ： Ce-Zr-basedOxide, Three-wayCatalyst, ExhaustGase