Effect of Surface Composition of Platinum-Ruthenium Nanoparticles on Methanol Oxidation Activity

• Published in: ECS transactions Vol. 33; no. 1; pp. 321 - 332
• Main Authors: Suzuki, Shuichi, Onodera, Taigo, Kawaji, Jun, Mizukami, Takaaki, Takamori, Yoshiyuki, Daimon, Hideo, Morishima, Makoto
• Format: Journal Article
• Language: English
• Published: 01.01.2010
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/1.3484530

Methanol oxidation activity of platinum-ruthenium nanoparticles on carbon supports was investigated as a function of the surface platinum-ruthenium composition. The surface composition of the platinum-ruthenium nanoparticles was measured with a technique combining copper under potential deposition and copper stripping. The measurements showed that the surface composition was not the same as the bulk composition even though X-ray diffraction analysis showed that all the platinum-ruthenium nanoparticles formed a solid-solution alloy. The methanol oxidation activity of the platinum-ruthenium nanoparticles was measured by linear sweep voltammetry using a rotating disk electrode in a 0.5 mol/l sulfuric acid solution containing 1.0 mol/l methanol at 308 K. This electrochemical analysis showed that the methanol oxidation activity did not correlate with the bulk composition but with the surface composition. Moreover, in the case of platinum-ruthenium nanoparticles, the maximum methanol oxidation activity was observed at a surface platinum-ruthenium composition of around 50 at.% ruthenium.