Octahedral Pt-Ni Nanoparticles for Electrocatalytic ORR – New Insights Using in-Situ Scattering, Spectroscopy and Microscopy

Tuesday, 3 October 2017: 14:00
National Harbor 2 (Gaylord National Resort and Convention Center)
V. Beermann (Technical University Berlin), M. E. Holtz (Cornell University), M. Gocyla (Forschungszentrum Juelich GmbH), S. Kühl (Technical University Berlin), E. Padgett (Cornell University), N. Erini (Technical University Berlin), M. Heggen, R. E. Dunin-Borkowski (Forschungszentrum Juelich GmbH), D. A. Muller (Cornell University), and P. Strasser (Technical University Berlin)
Shape-controlled octahedral Pt-Ni core shell nanoparticles have attracted much attention in recent years due to their promising oxygen reduction reaction (ORR) activities, presumably owing to their particular geometry and facet exposure. Yet much about their growth and degradation has remained insufficiently understood.

Here, we present some recent work where we learned more about the relations between particle synthesis, morphology, bulk structure, surface composition and their catalytic ORR activity and stability using, among others, in situ high-temperature TEM and in situ electrochemical TEM. We follow the particle morphology in real time during annealing protocols, and, using real time imaging, we track and observe changes in the catalyst structure and particle shape during different electrochemical treatments

Our study provides some interesting new insights in the real time behavior and degradation of shaped PtNi electrocatalysts, and may aid in out understanding of some of the parameters that will optimize the lifetime of the catalyst.