| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 50138 | Catalysis Communications | 2013 | 7 Pages |
XPS shows that the surface chemical state of Pd in Pd/ZrPrOx is mainly Pd4 +, which is likely doped in ZrPrOx. However, the Pd4 + is segregated out as PdO when Pd/ZrPrOx is exposed at 1000 °C in air, resulting in the particle growth of Pd and deterioration. It has been found that the mixing Pd/ZrPrOx with CeO2 enhances the catalytic activity and thermal durability. Analysis using XPS and HAADF-STEM shows that the mixing effect of ceria is to stabilize Pd4 + at the high temperature and ceria also functions as an excellent support for the segregated PdO, which migrates from ZrPrOx to CeO2.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Pd/Zr–Pr mixed oxide shows high resistance to the thermal ageing. ► RS proved that Pr-doping leads to the formation of peroxide and superoxide adspecies. ► Main chemical state of Pd in fresh catalyst was Pd4 + before reaction. ► In thermal ageing, Pd4 + ions segregate out as PdO, resulting in Pd particle growth. ► Mixing Pd/Pr-doped ZrO2 with ceria improved performance and thermal tolerance.
