Study of Ethanol Electrooxidation Reaction at Room Temperature on Nanometric Pt-Ru, Pt-Sn and Pt-Ru-Sn in Direct Alcohol Fuel Cells

Abstract

Ethanol electrooxidation in acid medium was investigated on Pt-Ru-Sn/C, Pt-Ru/C and Pt-Sn/C. The electrocatalysts were synthesized by microwave assisted chemical reduction reaction. The samples were characterized by transmission electron microscopy (TEM), X-ray diffraction analysis (XRD) and electrochemical analysis for the electrooxidation of ethanol. The ternary electrocatalyst was evaluated in an experimental Direct Ethanol Fuel Cell (DEFC). The method of synthesis used in this work allowed the formation of nanostructured electrocatalysts. The results obtained by electrochemical studies showed that the ternary system Pt-Ru-Sn/C exhibited the highest activity with respect to the binary systems Pt-Ru/C and Pt-Sn/C for carrying out the ethanol electrooxidation reaction. 0.4 mg∙cm-2 of electrocatalytic load of Pt-Ru-Sn/C was placed in the anode of an experimental fuel cell operating at room temperature. It was possible to obtain a power density of 0.14, 0.12 and 0.11 mW∙cm-2 after 20, 40 and 60 minutes respectively. The experiments were carried out at a controlled temperature of 297 K and they showed the feasibility to produce electricity at room temperature by using this ternary electrocatalyst in Direct Ethanol Fuel Cells.