EV vehicles make up 1% of car purchases in Japan in 2021. stricter emission standards are expected to be passed by the European Union. Improving the performance andFunctionality of exhaust gas purification catalysts in petrol or diesel powered vehicles is a critical component in the push towards carbon neutrality.
Almost all petrol and diesel cars have the ability to remove harmful hydrocarbons, carbon monoxide and nitrogen oxide and convert them into safer gases such as nitrogen, carbon dioxide and water Vapor. The toxic gases flow through a honeycomb structure.
The purification process depends on ceramics with an Oxygen Storage Capacity. They help remove noxious gases and prevent precious metals from being coarsened.
The operating temperature is needed to improve their potential. Scientists have been unable to achieve this since the temperature has been reduced to less than 500 oC.
A research group at Tohoku University's Graduate School of Engineering has developed a Cerium-Zirconium-based (Ce-Zr) oxide with excellent OSC at 400 oC. Even without precious metal catalysts the OSC was still higher than conventional materials.
The key to our success was introducing a tiny amount of transition metals, such as iron, to the Ce-Zr-based oxides.
There were two noticeable effects in the oxides. Oxygen vacancies and cation ordering were promoted by it.
"Cation ordering makes the crystal structure stronger and makes it easier to release oxygen," said Takamura.
The larger surface area for the Ce-Zr-based oxides was enabled by the reduction of the cation-ordering temperature. They were able to purify toxic gases.
Takamura and his group would like to test the material on honeycomb supports.
The details of the group's research were published in the Journal of Materials Chemistry A on September 27, 2022.
The low-temperature synthesis of cation-ordered Ce–Zr-based oxide via an intermediate phase between Ce and Fe is the topic of a recent article. The DOI is 10.1039/D2TA05068D.
Journal information: Journal of Materials Chemistry A
All Rights Reserved © 2024
