Abstract: The adsorption and oxidation of n-propyl alcohol on Pt and Pt modified with saturated adsorped Sb and S (Pt/Sbad and Pt/Sad ) electrodes were studied using cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM).The results demonstrated that the oxidation of n-propyl alcohol depends strongly on the oxidation states of the electrode surface.Sb adatoms on Pt surface can adsorb oxygen at relatively low potentials,and exhibit catalytic effects for n-propyl alcohol oxidation.In comparison with n-propyl alcohol oxidation at a Pt electrode,the oxidation peak potential of n-propyl alcohol on Pt surface modified with saturated Sbad was negatively shifted about 290 mV and the peak current was doubly increased.In contrary,the oxidation of S adatoms consumes oxygen species of Pt electrode surface.Consequently,the oxidation of n-propyl alcohol was inhibited on Pt surface modified with Sbad in saturation.The EQCM studies provided quantitative results of surface mass changes during n-propyl alcohol oxidation,and have thrown new light in elucidating different effects of adatoms Sbad and Sad on Pt electrode surface towards n-propyl alcohol oxidation.