Methanol Permeation Through Proton Exchange Membranes of DMFCs

This chapter presents efforts and progress being made by researchers worldwide to develop membranes with low methanol permeability, without compromising on other qualities, such as high ionic conductivity, good chemical and thermal stability, and cost. Three approaches have been pursued —Nafion membranes modification, development of alternative membranes, and development of high activity anode catalysts or methanol-tolerant cathode catalysts. Success has been made in developing membranes with permeability values of 10–70 times lower than the pure Nafion membranes. Various techniques, both electrochemical and non-electrochemical, for measuring methanol permeation through the membranes are also discussed. It has been found that electrochemical techniques are more accurate. Potentiometric technique in particular has ease of reproducibility of results, and getting more data points.