Density function theoretical study of interaction of hydrogen with ceria

Interaction of hydrogen with ceria is investigated by DFT-GGA calculations. Hydrogen adsorption on (111) and (110) surfaces is compared with insertion into the bulk and subsurfaces using VASP calculations. The calculations predict that hydrogen atoms insert within the bulk forming hydroxyl groups and slightly expanding the lattice. There is formation of an O-H...O sequence including an OH formation and a H-bonding. It is also concluded that the hydrogen uptake is due to H adsorption on the surface, followed by an athermic penetration in the subsuperficial region. The (110) orientation is more active than the (111) orientation.