Beneficial effects of rhodium and tin oxide on carbon supported platinum catalysts for ethanol electrooxidation
Layciane A. Soares, Claudia Morais, Teko W. Napporn, K. Boniface Kokoh, Paulo Olivi
This work investigates ethanol electrooxidation on Pt/C, PtxRhy/C, Pt-SnO2/C, and PtxRhy-SnO2/C catalysts synthesized by the Pechini and microwave-assisted polyol methods. The catalysts are characterized by energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. The electrochemical properties of these electrode materials are examined by cyclic voltammetry and chronoamperometry experiments in acid medium. The products obtained during ethanol electrolysis are identified by high performance liquid chromatography (HPLC). The adsorbed intermediates are evaluated by an in situ reflectance Infrared Spectroscopy technique combined with cyclic voltammetry. Catalysts performance in a direct ethanol fuel cell (DEFC) is also assessed. The electrical performance of the electrocatalysts in a single DEFC at 80 °C decreases in the following order Pt70Rh30SnO2 > Pt80Rh20SnO2 > Pt60Rh40SnO2 ∼ PtSnO2 > PtxRhy ∼ Pt, showing that the presence of SnO2 enhances the ability of Pt to catalyze ethanol electrooxidation.
Publicado em: Journal of Power Sources, Volume 315, 31 May 2016, Pages 47-55
ISSN 0378-7753
http://dx.doi.org/10.1016/j.jpowsour.2016.03.013.
http://www.sciencedirect.com/…/article/pii/S0378775316302142
