Theoretical investigation of hydrated hydronium ions on Ag(111)

P. PAREDES OLIVERA; A. FERRAL; E. M. PATRITO

American Chemical Society

Año: 2001 vol. 105 p. 7227 - 7227

e investigated the adsorption of hydronium ions on Ag(111) in conditions that simulate the structure of the double layer using the ab initio quantum mechanical Moller-Plesset second-order method. The most representative points of the potential energy surface for bare hydronium on Ag(111) were first investigated. Then, the ion was hydrated with 1, 2, and 3 water molecules, and the structures of the hydronium-water complexes were studied on Ag(111) under different externally applied homogeneous electric fields. Bare hydronium adsorbs via the hydrogen atoms with C3v or Cs symmetry. For these coordinations, the potential energy surface has a small corrugation: the binding energy on the hcp hollow site (-56 kcal/mol) is only 2 kcal/mol more stable than on the ontop site. On the other hand, adsorption via the oxygen atom is destabilized due to the Pauli repulsion with the metal. The equilibrium geometry of the trihydrated complex (H9O4+) has the water molecules located between the hydronium