A complementary combination of cyclic voltammetry,electrogravimetry,and electrochemical impedance spectroscopy has been used to characterize,in-situ,the underpotential deposition of atomic layers of Ag,Cu and Pb on the electrodes surfaces.The developed experimental approach provides co-adsorption and competitive adsorption of anions to be measured and quantified during the processes.Deposition of the Ag atomic layer is accompanied by surface alloying and specific adsorption of anions.Specific anion co-adsorption and surface alloying would inhibit the active sites of catalysts and impair the long-term stability of catalysts.The absence of these phenomena in Cu and Pb deposition processes suggests that these layers could be used as promising building blocks for catalytic application.It should be noted,however,the formation of Pb overlayers was complicated by H adsorption,which indicated that the catalytic application of the Pd layers would require a higher pH to negate such process.