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The fuel cells using direct methanol oxidation process (DMFC) are becoming important for many electronic gadgets such as cell phones, laptops, etc. In the attempts to miniaturizing these types fuel cells, different configurations have been used including screen printing the electrodes on PCB, thin films deposited on substrates and stacking the same. In such modifications, the electrochemical oxidation of methanol is required to be improved on thin film levels with limited surface contact and residence time as compared to conventional carbon cloth electrode. In our present investigation conducting polypyrrole electrodes of different roughness were prepared by electro-polymerization of pyrrole on vacuum metallized glass substrates. These were modified by doping them with ZrCl4 as dopant. The surface of the polymer film electrodes were characterized by SEM and AFM. These polypyrrole electrodes were employed to investigate electrocatalytic activity towards methanol electrochemical oxidation by means of cyclic voltammetry in 0.1M HClO4 as supporting electrolyte.
Various results obtained show that modified conducting polypyrrole was catalytically active towards electro-oxidation process. Results showed roughness of polypyrrole electrodes play a very important role in the electro-catalytic activity towards methanol oxidation. The catalytic activity increases with increase in roughness of the film which is confirmed from various characterization techniques. Effect of roughness on electrocatalytic activity was explained on the basis of availability of active surface sites and diffusion phenomena of the films.
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