Adsorption of hydrogen, chlorine, and sulfur atoms on α-Cr2O3(0 0 0 1) surfaces: A density functional theory investigation

Adsorption of atomic H, Cl, and S on the chromyl (CrO), oxygen (O), and chromium (Cr) terminated α-Cr2O3(0 0 0 1) surfaces is investigated using density functional theory (DFT). Adsorption of H is strongest on the CrO and O terminated surfaces. H preferably binds to O atoms of these surfaces. Adsorption of Cl and S atoms is strongest on the Cr terminated surface where the atoms preferably bond to Cr. Geometry preferences are explained by electronic structure analysis. Adsorption to Cr on the O terminated surface results in significant outward relaxation of the Cr atoms, causing significant bond breaking on the surface.

► DFT calculations show that H, Cl, and S interact strongly with chromia (0 0 0 1).
► The adsorption results in significant surface relaxation and bond breaking.
► Adsorption energies are in the range 2–5 eV.