Supported catalysts for alcohol oxidation synthesis and analysis of their catalytic activity

Supported Pt–Sn–Ir/C (P), Pt–Sn/C (PO) and PtRu/C (BH) catalysts with potential application in a direct alcohol fuel cell (DAFC) were prepared by chemical reduction employing Pechini (P), Polyol (PO) and NaBH4 (BH) methodology. The catalyst particles were characterized by high resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS) measurements were performed by using a glassy carbon working electrode covered with the catalyst in a 1 M (ethanol or methanol) + 0.5 M H2SO4 solution in the 25 to 60 °C temperature range. In all electrochemical measurements it was demonstrated that PtSnIr shows the best catalytic activity for both alcohols oxidation. The improvement is attributed to the presence of both SnO2 and IrO2 oxide in the Pt composite, though influence of particle size can not be discarded.