Selective dissolution of binary Pt–Co alloys of different compositions in sulphuric acid solution

Abstract The dissolution of Pt–Co alloys in a 0.5 M H 2 SO 4 solution has been studied under immersion and potential cycling conditions. Under immersion conditions, the Pt-enriched layer formed on Pt 50 –Co 50 and Pt 40 –Co 60 alloys suppresses further dissolution of Co. Potential cycling between 0 and 1.4 V vs. standard hydrogen electrode enhances the selective dissolution, but is suppressed in the initial stage. In contrast, the amount of selective dissolution of Co from Pt 30 –Co 70 increases linearly with time during the immersion. Potential cycling significantly accelerates the selective dissolution of Pt 30 –Co 70 . The selective dissolution mechanism of Pt–Co alloys is discussed in this paper.