Carbon supported Pt75M25 (M = Co, Ni) alloys as anode and cathode electrocatalysts for direct methanol fuel cells

The behaviour of carbon supported Pt75M25 (M = Co, Ni) electrocatalysts, both as anode and cathode materials, was investigated in direct methanol fuel cells (DMFCs) and compared to that of a pure Pt electrocatalyst on the same carbon support. The physical and morphological characteristics of these electrocatalysts were examined by XRD, XAS and TEM techniques. The performances of Pt75Ni25/C and Pt75Co25/C as cathode materials in DMFC were better than those of the same electrocatalysts as anode materials. When used as cathode materials the cell with Pt75Ni25/C showed a better performance than those with Pt/C or Pt75Co25/C both in terms of mass activity and specific activity. The performances of these electrocatalysts as anode materials in DMFC were similar to that of Pt. The enhanced performance of Pt75Ni25/C as cathode electrocatalyst was ascribed both to the improved activity for oxygen reduction and to the higher methanol tolerance of the alloy.