Binary and ternary anode catalyst formulations including the elements W, Sn and Mo for PEMFCs operated on methanol or reformate gas

In an exploratory approach to find improved electrocatalyst formulations binary and ternary carbon supported catalysts with the elements Pt and Ru, W, Mo or Sn, respectively, amending the choice of Pt and Pt/Ru catalysts by addition of non-Pt metal cocatalysts were manufactured by impregnation and a colloid method and tested towards their activity for anodic oxidation of H-2 containing 150 ppm CO. and of methanol. Membrane-electrode-assemblies with noble metal loadings of 0.4 mg cm(-2) were manufactured and tested in fuel cell operation at 75 degrees C with H-2 fuel contaminated by CO and at 95 degrees C for operation on methanol. Cocatalytic activities were found for the elements W and Mo for oxidation of H-2/CO and methanol while in the case of Sn a cocatalytic activity was only found for H-2/CO-oxidation. Both for oxidation of methanol and H-2/CO the system Pt/Ru/W was superior to the other systems tested. The colloid method was found to be highly suitable for synthesizing polymetallic PEM catalysts. (C) 1998 Elsevier Science Ltd. All rights reserved.