Pt dissolution is a leading cause of performance degradation in polymer electrolyte fuel cells, however, the mechanisms leading to accelerated Pt dissolution during potential cycling are unclear. In a new diagnostic application of our previously developed potentiostatic nanoparticle dissolution model, we outline here the use of the model as a method for determining the fundamental dissolution rate parameters that may control potential cycling induced electrochemically active surface area loss for supported Pt nanoparticles. We furthermore provide a pertinent foundation for the development of concerted experimental, theoretical, and modeling approaches for unraveling the mechanisms behind accelerated Pt dissolution. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3548504] All rights reserved.