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 different compositions viz. 9:1, 7:3 and 5:5 were prepared by NaBH4 reduction method at room temperature. Extensive cyclic voltammetric investigations in different solutions have been performed on these electrodes, as well as on smooth electrodes, with the aim of identifying suitable combinations of electrode structure and electrolyte/methanol mixtures which can prevent the formation of organic poisoning 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 pointed out.