The co-underpotential deposition (co-upd) of Cu2+ and Zn2+ ions was ex
amined on Pt(111) by voltammetry, as their upd occur in well separated
ranges of potential. Their upd processes were observed to take place
by transfer of two electrons in conformity with the Nernst equation. I
n phosphate solution of pH 4.5, the co-upd of Cu2+ and Zn2+ ions was f
ound to occur when Cu2+ concentrations were lower than those of Zn2+ i
ons. In solutions with pH less than or equal to 1, Zn2+ ions had littl
e effect on the features of the cyclic voltammogram of Cu2+ upd. The e
ffect of Br- ions on the cyclic voltammograms of co-upd was also inves
tigated. Copyright (C) 1996 Elsevier Science Ltd.