Direct alcohol fuel cells: Challenges and future trends

Abstract

Among the most considered future alternative energy conversion systems are fuel cells. A fuel cell is an electrochemical device that continuously and directly converts chemical energy to electricity with the most common technologies to be the Polymer Electrolyte Membrane Fuel Cells (PEMFC) and the Solid Oxide Fuel Cells (SOFC). In such devices hydrogen is considered as the preferred fuel in virtue of its high activity and its environmental benignity.Fuel supply is an important problem to be solved for the commercial application of fuel cells' technology. Conventional fuel-cell types require hydrogen as the fuel, which has to be free of impurities when operated at temperatures below 100°C. The storage and distribution of hydrogen is still one of the open questions in the context of a customer-oriented broad commercial market. The last two decades research effort has been devoted to Direct Alcohol Fuel Cells dedicated to overcome the hydrogen specific restrictions. In this direction direct alcohol fuel cells have been extensively studied and considered as possible power production systems for portable electronic devices and vehicles in the near future. However, because of the relatively low performances and the high cost of platinum-based catalysts, a number of research groups have oriented their efforts mainly towards the development: a) of low or non platinum electrocatalysts (anodes and cathodes) and b) of nanostructured electrocatalysts based on non-noble metals. The challenges and the prospects related to the low and non platinum anodes for direct alcohol (methanol and ethanol) PEM fuel cells are presented and discussed in the present work. © 2011 INESC Coimbra