Vacancy formation energies

1
Vacancy formation energies on Ce0.50Zr0.50O2
surfaces
The effects of Zr doping on CeO2 (i) Zr doping
induces a severe distortion of the unreduced
surface structure (ii) at the reduced Zr-doped
ceria(1 1 1) and (1 1 0) surfaces, the oxygen
anions around the oxygen vacancy show much larger
displacements than those on the pure CeO2(1 1 1)
and CeO2(1 1 0) surfaces (iii) an oxygen
vacancy is more easily formed around the Zr
dopant, and the reduction energy is lowered by
about 0.5-0.8 eV (iv) the excess electrons
left by the removed oxygen atom localize on the
two Ce cations neighboring the vacancy and thus
brings about the reduction of the two Ce4 ions
and (v) the atomic structure modification
induced by the Zr doping plays a vital role in
facilitating the reduction of the ceriazirconia
solid solution as compared to the pure ceria.
Vacancy formation energies (111) surface Ef
(CeO2) 2.8 eV Ef (Ce0.5Zr0.5O2) 2.1
eV (110) surface Ef (CeO2) 2.4 eV Ef
(Ce0.5Zr0.5O2) 1.8 eV