I am delighted to join this symposium and celebrate not only the scientific accomplishments of R. Adzic and but also his contributions to the mentoring of generations of scientists in the electrochemistry and electrocatalysis community. Without formal training in electrochemistry, learning and making high-quality electrochemical measurements is not straightforward. R. Adzic not only has trained a large number of students and postdocs but also has opened his laboratory to other research groups throughout his career, shaping and mentoring future generations of researchers. My own involvements in electrocatalysis in the past decade would not be possible without individuals like R. Adzic who is committed to mentoring and collaborating with researchers coming from other disciplines.

In this talk, I will discuss the mechanisms of Pt and Pt alloy catalyst instability and activity loss in fuel cells (1-2), limiting the lifetime of fuel cells, and how morphologies of Pt alloy particles can influence activity and stability (3-4).

1. Chen, S., H.A. Gasteiger, K. Hayakawa, T. Tada, and Y. Shao-Horn, Platinum-Alloy Cathode Catalyst Degradation in Proton Exchange Membrane Fuel Cells: Nanometer-Scale Compositional and Morphological Changes, Journal of the Electrochemical Society, 157, A82–97 January 2010.
2. Ferreira, P.J., G.J. la O’, Y. Shao-Horn, D. Morgan, R. Makharia, S. Kocha and H. Gasteiger, Instability of Pt/C Electrocatalysts in Proton Exchange Membrane Fuel Cells: A Mechanistic Investigation, Journal of the Electrochemical Society, 152, A2256–A2271 2005.
3. Chen, S., W.C. Sheng, N. Yabuuchi, P.J. Ferreira, L.F. Allard and Y. Shao-Horn, The Origin of Oxygen Reduction Activity of “Pt₃Co” Nanoparticles: Atomically Resolved Chemical Compositions and Structures, Journal of Physical Chemistry C, 113, 1109–1125 2009.
4. Han, B., C.E. Carlton, A. Kongkanand, R.S. Kukreja, B.R.C. Theobald, L. Gan, R. O'Malley, P. Strasser, F.T. Wagner, and Y. Shao-Horn, Record Activity and Stability of Dealloyed Bimetallic Catalysts for Proton Exchange Membrane Fuel Cells, Energy & Environmental Science, 8, 258-266 2015.