Preparation of New GDE based on polyaniline in oxygen reduction reaction for proton exchange membrane fuel cell

Considering the high cost of polymer electrolyte fuel cell catalysts, the concept of lowering the platinium loading required to provide acceptable performance has been of paramount intrest to reasercheres in this field [1]. Therefore it is essential to enlarge the effective surface area by diminishing the size of catalyst particles and to distribute the catalyst only on the surface of the electrode for a low platinum loading and use of the whole surface of catalyst [2]. Electron conductive polymers, such as polyaniline , polypyrrole, polythiophene, are very convenient substrates in order to disperse, at the molecular level, electrocatalytic materials, in such a way that each catalytic center will be accessible to the reactive molecule. Platinum and platinum-based alloy catalysts have been highly dispersed in conducting polymers to activate various electrochemical reactions: reduction of protons [3], oxygen reduction [4], hydrogen oxidation [5], and finally oxidation of small organic molecules, such as methanol [6]. In most caces, the electrocatalytic activities of such modified metallic electrodes are greater than that of bulk metals and it is to greatly reduce the amount of platinum in the electrode and thereby significantly lower its cost, for example, for application in fuel cells and battry.