A brief overview is given of the fuel cell families attracting interes
t today. Problems in the optimization of interfaces in fuel cells, in
particular in Polymer Electrolyte Fuel Cells (PEFCs) are discussed nex
t. The influence of the parameters of low precious metal loading, fuel
purity, oxygen solubility, and water distribution in the solid polyme
r electrolyte on the performance of cells are briefly described. Final
ly, some current problems in the development of Direct Methanol Fuel C
ells are presented.