The Effects of Cations and Anions on Hydrogen

The adsorption of hydrogen on the plat inum elec-trode has been the subject of extensive investigation [see. e.g., Ref. (1-10)]. Many questions persist, how-ever, as to the true nature of the mult iple hydrogen adsorption peaks observed in l inear sweep voltam-metry studies of single crystal as well as polycrystal-l ine platinum. Up to five peaks have been observed (10) in u l t rapure dilute sulfuric acid electrolytes. Factors which have been proposed to account for these mult iple peaks include different adsorption sites on a g iven crystal lographic plane, a distr ibution of surface crystal lographic orientations even with a given single crystal macro-orientation, induced heterogeneity as-sociated with the perturbing of adjacent sites by the adsorbed hydrogen itself, and the adsorption of anion