Time-Resolved Measurements of Dissolution Rates of Platinum and Palladium by a Solution Flow Cell combined with ICP-MS

Abstract

Time-resolved measurement system, consisting of the combination of a commercially available solution-flow cell and an inductively coupled plasma mass spectrometry, for the dissolution rate of platinum （Pt） and palladium （Pd） has been established in this study. A detection limit of the system was successfully improved by thinning the cell channel, and their limits for Pt and Pd were 0.13 pg cm^－2 s^－1 and 0.39 pg cm^－2 s^－1, respectively. When the system was applied to Pt and Pd under potential cycling mimicking start/stop condition in polymer electrolyte fuel cell （PEFC）, it was revealed that the dissolution of Pt and Pd started from the more negative potential reported in previous studies. Besides, we succeeded in the time-resolved measurement of Pt and Pd dissolution rates below open circuit potential for PEFC （ca. 1.0 V） and clarified that the dissolution mechanisms of Pt and Pd are different.