Structure-Stability Relationships for Fuel Cell Catalysts

Tuesday, 3 October 2017: 17:20
National Harbor 2 (Gaylord National Resort and Convention Center)
P. P. Lopes, D. Li, D. Strmcnik, P. A. Paulikas, D. Tripkovic, P. F. B. D. Martins, N. M. Markovic, and V. Stamenkovic (Argonne National Laboratory)
Our control over the catalytic activity for the Oxygen Reduction Reaction (ORR) is greater than our present understanding of the factors affecting the stability of catalyst surface atoms. Despite the significant progress in imaging the overall changes at the nanoscale that takes place during advanced degradation test (ADT) protocols, little is known about structure-stability relationships. Nonetheless, recent developments in combining in situ electrochemical methods to inductively coupled plasma with mass spectrometry (ICP-MS) allowed identification of element specific dissolution processes. Specifically, the development of a Stationary Probe Rotating Disk Electrode (SPRDE) system provided insights on Pt dissolution and how it is structure sensitive, highly dependent on electrolyte and double layer composition, as well as influenced by the nature of the electrocatalytic reaction. This serves as a baseline to understand the functional links between structure, activity and stability for a variety of Pt-Metal alloys, how their atomic scale morphology controls stability and activity, its implications for nanoparticle systems, and what strategies can be successfully employed to improve both activity and stability of these surfaces.