Effect of Ru addition on the structural characteristics and the electrochemical activity for ethanol oxidation of carbon supported Pt-Sn alloy catalysts

Binary Pt-Sn/C (1:1) and ternary Pt-Sn-Ru/C (1:1:0.3 and 1:1:1) catalysts were synthesized by reduction of precursors with formic acid, and their activity for ethanol oxidation was compared with that of commercial Pt/C and Pt-Ru/C catalysts. Linear sweep voltammetry measurements at 40 and 90 degrees C showed that for potentials higher than 0.3 V vs. RHE, the Pt-Sn-Ru/C (1:1:0.3) catalyst presents the highest activity for ethanol electro-oxidation, while the electrochemical activity of the Pt-Sn-Ru/C (1:1:1) catalyst was lower than that of both the binary Pt-Sn/C and Pt-Ru/C catalysts. Tests in a single direct ethanol fuel cell confirmed the superior performance of the Pt-Sn-Ru/C (1:1:0.3) electrocatalyst. The positive effect of the Ru presence in the Pt-Sn-Ru/C (1:1:0.3) catalyst was ascribed to the interactions between Sri and Ru oxides. (c) 2006 Elsevier B.V. All rights reserved.