Noble metal electrodes in aqueous solutions under a triangular potential sweep display current peaks due to the electrosorption and electrodesorption of hydrogen and oxygen species [1-7]. In molten bisulphate electrolytes these characteristics were previously observed for platinum [8-11] and are also common for iridium. The electrochemical behaviour of iridium (1 mm diameter wire, Johnson Matthey, 1.0 cm² apparent area) was studied in the NaHSO₄-KHSO₄ melts at 180-300°C using a conventional three compartment electrolysis cell. Its potential was referred to a Pt/H₂(1 atm)/KHSO₄(melt) electrode.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas