Electrochemical Silver Deposition Onto Pt(111) Surfaces

Abstract

The underpotential deposition (upd) of Ag onto Pt(111) produces surface structures exhibiting several interesting structural and electrochemical properties: (i) a contracted pseudomorphic Ag monolayer, (ii) deposition-dissolution hysteresis, (iii) an expanded lattice for the second Ag monolayer, (iv) absence of H upd , and (v) enhanced H 2 evolution activity of Ag overlayers compared with Ag(111). Related measurements under ultrahigh vacuum conditions reveal similar structural transformations, and DFT calculations indicate that there is a thermodynamic driving force for the migration of the first Ag(111) overlayer deeper into the electrode, upon deposition of the second monolayer. We will discuss adlayer formation and the link between structure formation and reactivity of the resulting surface.