Carbon supported platinum is commonly used as anode and cathode electrocatalyst in lowtemperature
fuel cells fuelled with hydrogen or low molecular weight alcohols. The cost of Pt and the
limited world supply are significant barriers to the widespread use of these types of fuel cells. Moreover,
platinum used as anode material is readily poisoned by carbon monoxide, present in the reformate
gas used as H2 carrier in the case of polymer electrolyte fuel cells, and a byproduct of alcohol oxidation
in the case of direct alcohol fuel cells. In addition, Pt alone does not present satisfactory activity for the
oxygen reduction reaction when used as cathode material. For all these reasons, binary and ternary
platinum-based catalysts and non-platinum-based catalysts have been tested as electrode materials
for low temperature fuel cells. Palladium and platinum have very similar properties because they belong
to the same group in the periodic table. The activity for the oxygen reduction reaction (ORR) of Pd is
only slightly lower than that of Pt, and by addition of a suitable metal, such as Co or Fe, the ORR
activity of Pd can overcome that of Pt. Conversely, the activity for the hydrogen oxidation reaction
(HOR) of Pd is considerably lower than that of Pt, but by adding of a very small amount (5 at%) of Pt,
the HOR activity of Pd attains that of pure Pt. This paper presents an overview of Pd and Pdcontaining
catalysts, tested both as anode and cathode materials for low-temperature fuel cells