Improvement of the homogeneity and oxygen storage capability of Ce1-xZrxO2-δ by co-doping: A first-principles study
The redox property of CeO2 can be greatly enhanced by incorporating zirconium ions into the lattice to form a solid solution. However, the solid solution tends to separate into CeO2 and ZrO2 individual phases. Adding a third metal (M) into the system is likely to retard this behavior if M and Zr att...
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Veröffentlicht in: | Journal of alloys and compounds 2020-03, Vol.817, p.153238, Article 153238 |
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Sprache: | eng |
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Zusammenfassung: | The redox property of CeO2 can be greatly enhanced by incorporating zirconium ions into the lattice to form a solid solution. However, the solid solution tends to separate into CeO2 and ZrO2 individual phases. Adding a third metal (M) into the system is likely to retard this behavior if M and Zr attract each other and form atomic pairs to make the diffusion process harder. In the present work we have carried out density-functional calculations for various metals (Al, Cr, Mn, Co, Mo, Tc, Ru, Rh, Pd, Cd, Gd and Th) to investigate the interactions between M and Zr. Our calculated results have shown that some dopants (M = Cr, Al, Mn, Co, Pd, Tc, Rh and Cd) can help to stabilize the zirconia-ceria solid solution and meanwhile improve the OSC property, while Th, Gd and Ru do not stabilize the solid solution and Th and Mo increase the formation energy of oxygen vacancy.
•Co-doping of a third metal with Zr helps to improve the homogeneity of Ce1-xZrxO2-δ.•Dopant and Zr may form atomic pairs, which can retard the phase separation.•Doping a third metal in Ce1-xZrxO2-δ increases the oxygen storage capability.•Interaction between Zr and a dopant is studied by first-principles calculations. |
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ISSN: | 0925-8388 1873-4669 |
DOI: | 10.1016/j.jallcom.2019.153238 |