Abstract
AbstractCeria‐based mixed oxides have proved to be good alternatives to pure ceria as redox materials for advanced three‐way catalysts. In this work, the behaviour of a Ce0.8Tb0.2O2−x mixed‐oxide sample and the corresponding oxide‐supported Rh and Pt samples has been investigated. Special attention has been paid to the low‐temperature redox response. Temperature‐programmed desorption (TPD), temperature‐programmed reduction and oxygen buffering capacity were used as experimental techniques. The evolution of reducibility was also followed by tunable high‐energy x‐ray photoemission spectroscopy, focussing on the surface information provided by Tb 3d and Ce 3d core levels. The oxidation state of both Ce and Tb was followed during ultrahigh vacuum annealing of the three samples up to 750 K. Comparison of the XPS spectra for the different samples before and after annealing showed that the Ce4+ reduction was negligible but Tb4+ was gradually reduced to Tb3+. Furthermore, the TPD and XPS experiments are in good agreement, with the highest reduction rate corresponding to the Rh/CeTbOx sample. Copyright © 2002 John Wiley & Sons, Ltd.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
