INFLUENCE OF PRE-ADSORBED Pt ON HYDROGEN ADSORPTION ON A B2FeTi (111) SURFACE

V. VERDINELLI, E. GERMÁN, P. JASEN, E. GONZALEZ, J.M. MARCHETTI

Cordoba

Congreso; HYFUSEN 2013; 2013

Comisión Nacional de Energía Atomica

The influence of Pt pre-adsorbed atoms and a Pt monolayer (ML) on hydrogen adsorption properties on a Fe-terminated B2-FeTi (111) surface was studied using the Density Functional Theory (DFT). The calculations were employed to trace relevant orbital interactions and to discuss the electronic consequences of incorporating two, three Pt atoms or a Pt ML on the top of FeTi surface. We found the optimum geometry for Pt and H atoms location as well as the Pt ML. The octahedral site was the most stable adsorption site for an isolated H atom. We also computed the density of states (DOS) and the overlap population density of states(OPDOS) in order to study the evolution of the chemical bonding. The OPDOS curves show that the presence of the hydrogen leads to a weakening of metal-metal bonding due to the formation of new bonds between metal-H; being the H-Fe bond the most developed. On the other hand, when a Pt ML covered the surface, the OP values indicate an increase in H-Pt and H-Ti interactions; the same interactions were lower in the case of the surface containing two and three Pt atoms.