Electrochemical characterization of platinum alloy catalysts - oxide growth and durability

The oxide growth on Pt alloy catalysts was studied by examining the surface oxidation on the Pt-Cu/C core-shell catalyst structure by combined CV and EQCM. The measurements show that the mass variation increases in a continuous linear manner as the potential is increased during the anodic oxidation, and from the in-situ molecular weight analysis, the intermediate adsorbed species is identified as hydroxide. The results are compared with the conventional unsupported Pt black and Pt/C which show that PtO is formed on the surface. From the reported results we found that the new catalyst surface is less oxidized and that surface strain imposes a barrier to surface oxidation.