Effect of tin deposition over electrogenerated random defects on Pt(111) surfaces onto ethanol electrooxidation: Electrochemical and FTIR studies

Publication date: Available online 9 December 2019Source: Journal of Electroanalytical ChemistryAuthor(s): Amaury F.B. Barbosa, Vinicius Del Colle, Nelson A. Galiote, Germano Tremiliosi-FilhoAbstractIn the present study, random superficial defects of the {110}-type were electrogenerated on an initially well-ordered Pt(111) single crystal electrode, by cycling the potential in the range from 0.05 to 1.30 V by 32 times in perchloric acid solution and in a scan rate of 0.05 V s−1, named as Pt(111)-32. After partial disordering of the electrode surface, it was modified by deposition of tin submonolayers in three different coverage degrees of Sn, namely, ѲSnDefects= 0, 0.34, 0.54 and 1.0. The Sn is preferentially deposited on the {110}-type defects generated previously. The effect of tin over the electrocatalytic activity for the ethanol electrooxidation reaction (EOR) and CO oxidation was investigated by using cyclic voltammetry, while the mechanism of the alcohol oxidation on the unmodified and Sn-modified electrodes was investigated by using in situ Fourier Transform Infrared (FTIR) spectroscopy. The lower Sn coverage degree on defect sites (ѲSnDefects= 0.34) showed, in the first voltammetric cycle, very good performance for EOR, having a peak current at 0.58 V twice the one observed for the unmodified Pt(111)-32 electrode. However, the situation changed in the second voltammetric cycle, where on the full Sn covered defect sites electrode (ѲSnDefects= 1) a better e...
Source: Journal of Electroanalytical Chemistry - Category: Chemistry Source Type: research