In this paper the effect of current density and temperature on the production of electrolytic manganese dioxide (EMD) from acidic manganese sulfate solutions was studied by linear sweep voltammetry, scanning electron microscopy and surface area measurements (BET). At 65ºC, it was observed that the EMD production was limited by the passivation of the titanium anodes, but at 90ºC this effect was substantially reduced. It was also verified that the increase of current density and the decrease of temperature lead to a considerable increase of the specific surface area of the EMD deposit. The higher surface area, 168m²/g, was obtained with a current density of 8mA/cm², in a 0.34M H2SO4 solution, at 65ºC, while the smaller, 52m²/g, was obtained with a current density of 4mA/cm², in the same solution, at 90ºC.
Electrolytic manganese dioxide; surface area; voltammetry
