We discuss the electrochemical reactions at the oxygen electrode of an aprotic Li-air battery. Using density functional theory to estimate the free energy of intermediates during the discharge and charge of the battery, we introduce a reaction free energy diagram and identify possible origins of the overpotential for both processes. We also address the question of electron conductivity through the Li2O2 electrode and show that in the presence of Li vacancies Li2O2 becomes a conductor.

Adsorption dynamics of O 2 on Cu͑100͒ and on reconstructed Cu͑100͒-͑2 ͱ 2 ϫ ͱ 2͒R45°-O at 300 and 553 K have been investigated by employing a supersonic molecular-beam surface-scattering technique. Experimental results suggest that an activated direct adsorption channel is operative on the clean Cu͑100͒, whereas the adsorption of O 2 on the reconstructed Cu͑100͒ is mediated either by a precursor state or by steering effects. First-principles molecular-dynamics simulations and potential-energy surface calculations show that the nature of the adsorption dynamics of O 2 is different between the clean and reconstructed Cu͑100͒ surfaces. The O 2 molecule is likely to diffuse away from the reconstructed area or to completely desorb from the surface, while in the case of the clean Cu͑100͒ surface, the adsorption occurs through a direct dissociative trajectory. We also find that in the case of the reconstructed surface, the steering occurs higher over the surface and that the recoil effect does not modify the surface as much as in the case of the clean surface. Moreover, the mobility of O and Cu adatoms on the reconstructed Cu surface is significantly lower than that on the clean surface both in the direction of the missing rows and in the direction perpendicular to them.

We present the results of ab initio calculations describing the adsorption of certain small organic molecules on clean and oxidized Al(111) surfaces as well as on the α- Al(2)O(3)(0001) surface. Our results show that adsorption of benzene on the clean and oxidized Al(111) surfaces is generally weak, the adsorption energy being at most around -0.5 eV per benzene molecule, and the molecule adsorbed at a considerable distance from the surfaces. The adsorption energy varies weakly at the different adsorption sites and as a function of the oxygen coverage. For the alumina surface, we find no benzene adsorption at all. We have also calculated for a phenol molecule on the aluminum and alumina surfaces, since it is similar to the benzene molecule. The results show a weak adsorption for phenol on the alumina surface and no adsorption on the aluminum or oxidized aluminum surfaces at all. For the propane molecule there is no adsorption on either the oxidized aluminum or the alumina surface, whereas the carbonic acid molecule binds strongly to the alumina but not to the aluminum surface.

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Using first principles density functional theory calculations, we have studied the adsorption of carbon monoxide (CO) on clean, Ag and Pd doped MgO(001), TiO 2 (110), and a-Al 2 O 3 (0001) surfaces. Our results show that adsorption of CO on the clean surfaces is generally weak. Ag doping improves the adsorption only weakly, except on the TiO 2 surface. The presence of Pd, however, significantly improves adsorption on all the surfaces studied. On the doped surfaces, the best adsorption sites are always the sites on top of the transition metal adatom, and the interaction range is 3-4 Å around an isolated adatom.