Chemistry of Doped Oxides: The Activation of Surface Oxygen and the Chemical Compensation Effect

We use density functional theory to study the chemistry of oxides doped substitutionally with cations having lower valence than that of the host. We document two rules. (1) The presence of the dopant makes the oxide a better oxidant. (2) Adsorbing an electron donor on the surface counteracts strongly the effect of the dopant. We discuss how these rules affect methane activation by doped-oxide catalysts.