L.F. Magana

A theoretical study of the interaction of hydrogen and oxygen with palladium or gold adsorbed on pyridine-like nitrogen-doped graphene.

The interaction of H2 and O2 molecules in the presence of nitrogen-doped graphene decorated with either a palladium or gold atom was investigated by using density functional theory. It was found that two hydrogen molecules were adsorbed on the palladium atom. The interaction of these adsorbed hydrogen molecules with two oxygen molecules generates two hydrogen peroxide molecules first through a Eley-Rideal mechanism and then through a Langmuir-Hinshelwood mechanism. The barrier energies for this reaction were small; therefore, we expect that this process may occur spontaneously at room temperature. In the case of gold, a single hydrogen molecule is adsorbed and dissociated on the metal atom. The interaction of the dissociated hydrogen molecule on the surface with one oxygen molecule generates a water molecule. The competitive adsorption between oxygen and hydrogen molecules slightly favors oxygen adsorption.

Ab initio calculation of the pressure dependence of the lattice specific heat of aluminum

Abstract From a first-principles local pseudopotential we calculated the interionic potential, phonon dispersion curves, phonon spectra and lattice specific heat as functions of pressure for aluminum. The pseudopotential was found from the electron density around an aluminum nucleus in an electron gas.

LATTICE SPECIFIC HEAT AND ELASTIC CONSTANTS OF hcp SODIUM

Abstract Sodium undergoes a martensitic transformation passing from a bcc structure to an hcp structure, below 35 K. Using a first principles pseudopotential, we calculated the constant volume lattice specific heat and elastic constants of both hcp and bcc sodium for temperatures below 35 K, for comparison.