Catalytic effects produced by cathodisation of platinum electrodes in sulphuric solutions

The effect of strong cathodisation of platinum electrodes in 0.5 M H2SO4 aqueous solutions is investigated using electrochemical and surface analysis techniques. This pretreatment activates the electrode for methanol electrocatalytic oxidation, with an approximate threefold increase in the anodic currents measured in the potential region between 0.6 and 0.75 V (versus RHE). After long cathodisation, heterogeneous sulphur deposits localised near shavings or kinks, which promote the formation and detachment of hydrogen bubbles, are detected on the platinum electrode.