Abstract: The dissociative adsorption of ethylene glycol (EG) on Pt(111) electrode has been investigated with electrochemical cyclic voltammetry and programmed potential step technique. The quantitative results demonstrated that the average rate of dissociative adsorption of ethylene glycol on Pt(111) electrode depends on electrode potentials, yielding a distribution of volcanic shape on adsorption potentials between －0.20 and 0.35 V with the maximum value of 3.90×10－12 mol•cm－2•s－1 located near 0.10 V(vs SCE).From the variation of the quantity of dissociative adsorbates determined through the oxidation charge with adsorption time (tad), the initial rate (vi) of this surface reaction has been evaluated quantitatively. The maximum of vi was ascertained to be 4.35×10－12 mol•cm－2•s－1 at 0.10 V for a solution containing 2×10－3 mol•L－1 EG.

Key words: Ethylene glycol, Dissociative adsorption, Pt(111) electrode, Surface reaction kinetics, Programmed potential step technique