Relative Stabilities of Low Index and Stepped CeO2 Surfaces from Hybrid and GGA + U Implementations of Density Functional Theory

R.M. FERULLO, M.M. BRANDA, F. ILLAS

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Año: 2011 vol. 115 p. 3716 - 3721

1932-7447

The relative stability of nine different well defined CeO2 surfaces has been studied by periodic density functional calculations using GGAþU and B3LYP exchange-correlation functional. Both methods consistently predict that CeO2(111) is the most stable surface and also provide a consistent picture of the most stable surfaces which indeed are in agreement with previous studies based on empirical interatomic potentials. The facility of ceria surfaces to undergo a redox process has been investigated by forcing spin-polarized solutions,which lead to the occupancy of Ce 4f orbitals. These calculations provide evidence that surfaces with low-coordinated Ce cations are likely to be reduced more easily than regular low-index Miller surfaces.