The electrocatalytic properties and durability of IrO_2-Ta_2O_5-SnO_2 / Ti anodes prepared by thermal decomposition methods have been studied in order to develop an oxygen evolution anode for tin plating using p-phenolsulfonic acid (PSA) baths. The anodic polarization curves and lifetime of the IrO_2-Ta_2O_5-SnO_2 / Ti anodes having different ratios of SnO_2 in the catalytic layers were compared to those of IrO_2-Ta_2O_5 / Ti anodes. The oxygen overpotential in the sulfuric acid solution was almost identical for the IrO_2-based anodes irrespective of the addition of SnO_2 inthe catalytic layer. Although the oxygen overpotential on the IrO_2-Ta_2O_5 anode increased as the sulfuric acid solution contained PSA, the increase in overpotential was suppressed on the IrO_2-Ta_2O_5-SnO_2 / Ti anodes, especially for those having higher ratios of SnO_2 in the catalytic layer. The addition of SnO_2 in the catalytic layer also affected the lifetime of the IrO_2-based anode in the PSA solution. The lifetime of the IrO_2-Ta_2O_5-SnO_2 / Ti anode in the PSA solution was prolonged compared to the IrO_2 - Ta_2O_5 / Ti anode, and the prolongation was more remarkable with the increasing ratio of SnO_2 in the catalytic layer.
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