Electrooxidation of methanol on polyaniline without dispersed catalyst particles

Electrooxidation of methanol in H2SO4 is studied on platinum and polyaniline (PANI) deposited platinum electrodes by cyclic voltammetry. In contrast to reports in the literature, which suggest the need of fine particles of a catalyst dispersed in PANI matrix for occurrence of electrooxidation of CH3OH, in the present study, the reaction is shown to take place on PANI without additional catalyst particles at CH3OH concentrations higher than 1 M. At lower concentrations, adsorption of CH3OH occurs on PANI resulting in a reduction in intrinsic voltammetric peak currents of PANI in H2SO4. The kinetics of adsorption follows Langmuir isotherm. By a comparison of cyclic voltammetric peak currents of methanol on platinum and PANI deposited platinum electrodes, the catalytic efficiency of PANI towards oxidation of CH3OH is evaluated.