Carbon supported Pt-Co alloys as methanol-resistant oxygen-reduction electrocatalysts for direct methanol fuel cells

The electrocatalysis of the oxygen reduction reaction on carbon supported Pt and Pt-Co (Pt/C and Pt-Co/C) alloy electrocatalysts was investigated in sulphuric acid (both in the absence and in the presence of methanol) and in direct methanol fuel cells (DMFCs). In pure sulphuric acid Pt-Co/C alloys showed improved specific activity towards the oxygen reduction compared to pure platinum. In the methanol containing electrolyte a higher methanol tolerance of the binary electrocatalysts than Pt/C was observed. The onset potential for methanol oxidation at Pt-Co/C was shifted to more positive potentials. Accordingly, Pt-Co/C electrocatalyts showed an improved performance as cathode materials in DMFCs.