Effects of Mn, Pr, Sn, Zr, Se and Te doping on redox properties of CeO₂

Abstract

The effects of <italic>M </italic>(<italic>M</italic>=Mn, Pr, Sn, Zr, Se, Te) doping on the redox thermodynamics of CeO₂ have been investigated using the first-principles density-functional theory considering the on-site Coulomb interaction within the PBE+<italic>U </italic>scheme. Two different mechanisms for the O-vacancy formation in doped CeO₂ have been clarified. Compared with the case of pure CeO₂, the decrease in the O-vacancy formation energy for the Zr-, Se-, Te-doped CeO₂ is mostly caused by the structural distortion, whereas the decrease for Mn-, Pr-, or Sn-doped CeO₂ originates from the electronic modification as well as from the structural distortion. It is found that the electronic modification occurs in those dopants whose uttermost atomic orbitals are half or fully occupied by the filling of the excess electrons left by the formation of the O vacancy.

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