CeO2 promoted with either 1 wt% Pt or 1 wt% Pd was evaluated as a model system for passive NOx adsorber applications. According to NOx storage experiments conducted over the temperature range 80-160 °C, promotion with Pt resulted in higher NOx storage efficiencies than for the Pd-promoted material. However, for NOx storage at 80 and 120 °C, the latter released more NOx below 350 °C during temperature-programmed desorption in relative and absolute terms, the Pt analog releasing most of its stored NOx above 350 °C. DRIFT spectra showed that the use of Pd leads to preferential adsorption of NOx in the form of nitrites, while predominately nitrate formation is observed over the Pt promoted material. Overall, the use of Pd promoted CeO2 is preferred for low temperature NOx storage and release due to its ability to store NOx as thermally labile nitrites.
|Number of pages||9|
|State||Published - May 2016|
Bibliographical noteFunding Information:
The authors thank Shelley Hopps for XRD measurements, as well as Drs. Christine Lambert and Joe Theis of Ford Motor Co. for helpful discussions. This project was funded by the National Science Foundation and the U.S. Department of Energy (DOE) under award no. CBET-1258742. However, any opinions, findings, conclusions, or recommendations expressed herein are those of the authors and do not necessarily reflect the views of the DOE.
© 2016 Springer Science+Business Media New York.
- Passive NO adsorber
ASJC Scopus subject areas
- Chemistry (all)