The direct methanol fuel cell

The principle fuel used to derive power from fuel cells has to date been hydrogen. Hydrogen is generated primarily by the reformation of hydrocarbon based feedstocks such as methane and methanol. Such generation immediately suggests a loss in efficiency in fuel utilisation as well as increased system cost. Thus the direct use of hydrocarbon based fuels in fuel cells is an attractive option. In this respect, methanol is a suitable fuel being readily stored as liquid under ambient conditions. Research has been concerned with the development of direct methanol fuel cells using polymer electrolyte membranes which can operate at low temperatures. Such cells are seen as promising candidates for applications ranging from portable power sources (battery replacement applications) to power sources for electric vehicles. Direct methanol fuel cells are based on membrane electrode assemblies (MEA) comprising of thin commercial proton conducting solid polymer membranes onto which thin catalyst layers of Pt-Ru for anode and Pt for cathode dispersed on carbon and bond with solubilised Nafion are dispersed. This structure sandwiched between two highly porous carbon cloth backing layers which enable appropriate fuel and oxidant supply to the catalysts while providing electrical contact to the current collectors