Synthesis and characterisation of alkaline anionic-exchange membranes for direct alcohol fuel cells

Abstract

Great effort in research and development has been made over the years to improve and commercialize new electricity generating systems. To provide an alternative energy carrier, an appropriate conversion technology is needed to form high quality power with the highest efficiency and low emission of pollutants. Fuel cells (FCs) are ideal candidates to meet these requirements. FCs are electrochemical devices that convert chemical energy directly into electrical energy. Several kinds of FCs exist, but the most important being proton exchange membrane fuel cell (PEMFC), which uses an acidic membrane like Nafion (sulfonated fluorocarbon polymers) as an electrolyte. The use of polymer electrolytes represents an interesting path to pursue for these electrochemical devices. Moreover, when Nafion membranes are applied to direct alcohol fuel cells (DAFCs), several major obstacles emerge, i.e. methanol crossover and relative low activity. The crossover reduces the operational voltage and the power that can be achieved. One of the major disadvantages of the proton exchange membrane is the high cost of the membrane electrode assembly (MEA), related: (i) to an expensive polymeric membrane and (ii) to the use of platinum catalysts.2 Therefore, this implied that there is an urgent need for the development of novel anion exchange membranes (AEMs) that can be applied in FCs. In alkaline fuel cells, the OH- anions are produced at cathode and then transported through the membrane to the anode where they are quantitatively consumed. This poster will present a brief overview on preparation and characterization of anion exchange membranes (AEMs) using poly(arylene ethers) (PEAs) as well as the modification of commercially available PEAs, for example, polysulfone (Udel) and polyphenylsulfone as base polymers for the membranes. Characterization of these polymeric membranes will be presented with reference to recent advances as reported in literature