DIFFERENTIAL CAPACITANCE AND CYCLIC VOLTAMETRIC STUDIES ON SMOOTH LEAD IN H2SO4 SOLUTIONS

One method for studying adsorption at an electrode surface is to obtain curves showing the relationship between differential capacitance and electrode potential. The purpose of this work was to determine the extent to which organic additi%0es, having known degrees of expander activity, alter the shape of such curves obtained with smooth lead electrodes in H//2SO//4 solutions. Also included in this study were cyclic voltametric experiments to measure the electric current that flowed throughout the potential rangeat which the differential capacitance measurements were made. The adsorption of an organic expander at a smooth lead electrode is undoubtedly distributed differently than that at a lead-acid battery negative plate. Because of its porous nature, the negative plate possesses reaction sites having a wide range of activity. Unlike the smooth lead electrode where the adsorption may be dist%ributed over most of the electrode surface, adsorption at the negative plate may occur only at the most active reaction sites.