Pt-Co/C electrocatalysts for oxygen reduction in H-2/O-2 PEMFCs synthesized by borohydride method

A Pt-Co/C electrocatalyst with Pt: Co atomic ratio 85: 15, prepared by a low-temperature chemical reduction with sodium borohydride, was studied as possible cathode material for polymer electrolyte membrane fuel cells (PEMFCs). The physical characterization of this electrocatalyst was performed by energy-dispersive X-ray analysis, X-ray diffraction, and transmission electron microscopy. The performance of the material was evaluated by cyclic voltammetry and polarization experiments in a single PEMFC and compared with those of an unalloyed Pt/C catalyst prepared by the same method and a commercial Pt-Co/C catalyst. Both the Pt-Co/C catalysts were also submitted to a thermal treatment in a reducing atmosphere. (C) 2004 The Electrochemical Society.