Using a multiway chemometric tool in the evaluation of methanol electro-oxidation mechanism
Abstract: In the present work, an innovative methodology is used to contribute in the elucidation of methanol electro-oxidation reaction on polycrystalline Pt surface. We coupled infrared spectroscopy to linear voltammetry and evaluate the data using parallel factor analysis (PARAFAC) to extract hidden information concerning the oxidation reaction. Five adsorbed species were simultaneously extracted and quantified at different applied potentials corresponding to: formate, sulfate, water, total CO and COL shift. It was observed that the CO adsorbed content starts at maximum on low potentials and gradually decreases up to 1.0 V. Meanwhile, the interfacial water content on the surface of the CO-free Pt increases, which causes the shift on the COL band, resulting in a further decrease of the interfacial water content. The water content increases again until up to 0.8 V, which it reaches a constant value, due to formate production and subsequent adsorption of sulfate. Using this technique, it was possible to determine the potential window where each chemical species is adsorbed on the surface, as well as the effect of methanol concentration and scan rate on the mechanism.
Author(s): Silva, CD ; Corradini, PG ; Mascaro, LH ; Lemos, S ; Pereira, EC
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
Volume: 855 Pages: Published: 150DEC 2019
DOI: 10.1016/j.jelechem.2019.113598
