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O: Fachverband Oberflächenphysik
O 8: Solid-Liquid Interfaces 1: Reactions and Electrochemistry
O 8.6: Talk
Monday, September 5, 2022, 12:00–12:15, S054
Towards Understanding Platinum Degradation: Modelling the Growth of Nanoislands — •Francesc Valls Mascaro1, Marc T.M. Koper1, and Marcel J. Rost2 — 1Leiden Institute of Chemistry, Leiden University — 2Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University
Platinum is the catalyst of choice in many electrochemical energy conversion systems like fuel cells due to its superior activity. However, the stability of platinum catalysts is limited under fuel cell operation conditions. This degradation process has been extensively studied by cyclic voltammetry and inductively coupled plasma mass spectrometry (ICP-MS) [1, 2]. The origin of this degradation is most likely linked to the roughening of the surface due to the nucleation and growth of platinum nanoislands [3, 4, 5, 6]. In this work, we model, fully analytically and with the support from electrochemical data, the growth of these nanoislands on Pt(111) in perchloric acid. The model here presented successfully describes the surface growth taking place during the oxidation-reduction cycling. Different parameters such as the flux of adatoms and vacancies were obtained from the fittings between the model and the experimental data.
References: [1] Topalov, A. et al., Chem. Sci., 5, 631 (2014) [2] Sandbeck D.J.S. et al., ACS Appl. Mater. Interfaces, 12, 25718 (2020) [3] Jacobse, L. et al., Nat. Mater. 17, 277 (2018) [4] Jacobse, L. et al., ACS Cent. Sci. 5 (12), 1920 (2019) [5] Rost, M.J. et al., Nat. Commun. 10, 5233 (2019) [6] Ruge, M. et al., J. Am. Chem. Soc., 139, 4532 (2017)