Density functional theory calculations are used to investigate the energetics of protons crossing triple phase boundaries based on a metal catalyst, Pd or Ni, and barium zirconate. Our calculations show that the proton transfer reaction at these interfaces is controlled by the terminal layer of the electrolyte in contact with the metallic and gas phases. The hydrogen spilling process onto the electrolyte surface is energetically favored at peripheral sites of the metal–electrolyte interface, and proton incorporation into the sub-surface region of the electrolyte involves energies of the order of 1 eV. At the triple phase boundary, the energy cost associated with the proton transfer reaction is controlled by both the nature of chemical contact and the Schottky barrier at the metal–electrolyte interface.

Density functional theory calculations are carried out to model the structure and interpret recent X-ray photoelectron spectroscopy measurements of graphene oxide films obtained by Hummers oxidation of multilayer graphene grown epitaxially on silicon carbide. The confrontations between theory and experiment are used to gain insight into the nature and fraction of the oxygen functional groups present in the oxide films. The study shows that this type of graphene oxide films includes small amounts of intercalated water molecules, ether groups, and doubly oxidized carbon species and that the oxidized graphene sheets encompass a disordered and homogeneous distribution of epoxide and hydroxyl species. The results of our spectral analysis are corroborated by a study of the energetic stability of water in this form of graphene oxide.

Density functional theory calculations are used to investigate the energetics of protons crossing triple phase boundaries based on a metal catalyst, Pd or Ni, and barium zirconate. Our calculations show that the proton transfer reaction at these interfaces is controlled by the terminal layer of the electrolyte in contact with the metallic and gas phases. The hydrogen spilling process onto the electrolyte surface is energetically favored at peripheral sites of the metal–electrolyte interface, and proton incorporation into the sub-surface region of the electrolyte involves energies of the order of 1 eV. At the triple phase boundary, the energy cost associated with the proton transfer reaction is controlled by both the nature of chemical contact and the Schottky barrier at the metal–electrolyte interface.