Thermodynamic Clusters Stability of Molecular Hydrogen Adsorbed on Model Surfaces

Thermodynamic stability of molecular hydrogen clusters adsorbed on model surfaces

The study of molecular hydrogen adsorbed on surfaces has attracted the attention of researches because of it importance in fuel cell. Obtaining information of this system is of paramount important in the possible development of efficient technologies. In this study the stability of H2 clusters was calculated using computer simulations. Specifically Path Integral Monte Carlo techniques, couple with thermodynamic integration was implemented for the calculation of the change in Gibbs free energy. The surface was modeled using well ?known interparticle potentials which include surface corrugation. Six different temperatures were considered and a constraining potential was used in order to eliminate undesirable thermodynamic events. The results show that quantum effects cause the stabilization of the molecular hydrogen clusters adsorbed. Moreover, upon surfaces corrugation the clusters become thermodynamically unstable for all sizes considered.