Electrochimica Acta, Vol.39, No.11-12, 1525-1530, 1994
Palladium Adsorption on Pt(111) - A Combined Electrochemical and Ultra-High-Vacuum Study
Palladium was deposited from vacuum onto Pt(111) and gave rise to Frank-Van der Merwe (layer-by-layer) growth. High quality (1 x 1) LEED patterns are always observed with no indication of any other ordered phases over the entire coverage range of palladium studied (20 monolayers). This behaviour is consistent with growth of (1 x 1) palladium islands and is expected on the basis of lattice mis-match and surface energy arguments. Clean transfer of a pre-adsorbed palladium layer supported on Pt(111) to an electrochemical cell confirms the well-defined nature of the surface. Clear voltammetric features associated with first and second layer palladium adatoms are observed. The Auger data also supports the palladium coverage assignment proposed by Clavilier and co-workers on the basis of purely electrochemical measurements. No significant structural or chemical differences are to be found between palladium films grown by forced deposition of Pd-aq(2+) ions utilizing gaseous hydrogen and those formed by vacuum deposition.
Keywords:AUGER-ELECTRON-SPECTROSCOPY;BEHAVIOR