The catalytic activation of polycrystalline platinum toward ethanol electro-oxidation in alkaline environment has been obtained by a square wave potential treatment.A detailed analysis that explores the effect of the period of the square wave on the evolution of the catalytic properties of the Pt surface is reported. The catalytic behavior of the treated and untreated surfaces has been interpreted both in terms of real surface area and surface structure evolution.The most active surface has been produced with a treating period time of 120. min. Interestingly the maximum stability has been obtained with the sample produced with square wave potential with a period of 360. min with slightly lower initial performance.We have also found that the treated samples limit C. C cleavage, as compared to bare Pt, offering an effective strategy to minimize the formation of CO. Via in situ FTIR we have demonstrated that the major oxidation product is acetate. These findings are especially important in view of the application of Pt as a catalyst in alkaline direct ethanol fuel cells.