Adsorption of carbonate species on silver. I. Nature of the surface bond.

E. M. PATRITO; P. PAREDES OLIVERA

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 1998 vol. 22 p. 1237 - 1237

he adsorption of carbon trioxide, carbonate and bicarbonate is investigated on the 111, 110 and 100 surfaces ofsilver from a quantum mechanical point of view. Several aspects of the metal/ion bonding such as the adsorbatebinding energy, charge transfer to/from the metal and the relaxation of the adsorbates upon adsorption areinvestigated. On the hollow site of Ag(110) bicoordinated carbonate has a binding energy of 226.9 kcal/mol. Thehighest binding energies for carbonate are obtained on Ag(110) while on Ag(111) and Ag(100) comparable bindingenergies are observed. The bicarbonate ion has a binding energy of 74.0 kcal/mol bicoordinated on the hollow siteof Ag(100). The binding energy of bicoordinated CO3 is 117 kcal/mol on Ag(100). There is a charge transfer towards the metal of 0.5 electrons in the case of carbonate and 0.25 electrons for bicarbonate. On the other hand, CO3 adsorption leads to a charge transfer of 1.5 electrons from the metal to the adsorbate. Adsorbed carbonate and c