Possibilities of prevention of formation of poisoning species on direct methanol fuel cell anodes

Porous unsupported Pd, Pt and Pt-Ru single phase alloy electrodes with diff erent compositions viz. 9:1, 7:3 and 5:5 were prepared by NaBH4 reduction m ethod at room temperature. Extensive cyclic voltammetric investigations in different solutions have be en performed on these electrodes, as well as on smooth electrodes, with the aim of identifying suitable combinations of electrode structure and electr olyte/methanol mixtures which can prevent the formation of organic poisonin g species. Various electrochemical processes occurring in different potential regions are discussed. Meanings of the appearance/disappearance of oxidation peaks during both forward and backward sweeps on the present electrodes are point ed out. (C) 2001 Elsevier Science B.V. All rights reserved.