Datensatz

Zusammenfassung

The distinction between surface hydration and reaction processes in ultrahigh vacuum studies of electrochemical phenomena is illustrated by coadsorption of H₂O with: (i) Cs on Cu(110); at low caesium coverages, solvation of the adsorbed alkali is observed and above a critical coverage of θ_Cs = 0.15 a surface reaction occurs forming hydroxide and hydrogen. Work function measurements have also been used to characterize the dielectric screening by interfacial water; (ii) hydrogen on Cu(110) and Pt(111): TDS and HREELS measurements using isotopic substitution of hydrogen by deuterium have been used to investigate the formation of (H₃O⁺)_ad. Whereas on Cu(110) hydrogen is merely solvated by water, on Pt(111) there is evidence for the production of hydrated protons.