(324g) Physico-Chemical Effects On Adsorbates Confined Between Metallic Surfaces

Density functional theory is used to investigate the interaction between Pt(111) and PtX (111) skin surfaces (with X=Ir,Pd,Ti,Cu,Fe), clean and in the presence of atomic and molecular oxygen and hydrogen, as a function of the distance between the two surfaces. It is found that the confinement effect produces a series of new physicochemical phenomena, including changes in the surface-subsurface distance between the approaching surfaces, variation in the adsorption energy of the atomic and molecular species, and dissociation of the molecular species when the separation between surfaces becomes lower than particular threshold distances; in addition, a possible relation between the electronic nature of the approaching surface and distance between the two surfaces will be presented. It is suggested that these findings may be useful for designing novel devices for catalysis and sensors, and to elucidate the role of cracks in surface degradation behavior.