%0 Journal Article %T Atomic-scale restructuring of hollow PtNi/C electrocatalysts during accelerated stress tests %+ Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces (LEPMI ) %+ Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA ) %+ Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM) %A Dubau, Laetitia %A Lopez-Haro, Miguel %A Durst, Julien %A Maillard, Frederic %< avec comité de lecture %@ 0920-5861 %J Catalysis Today %I Elsevier %V 262 %P 146-154 %8 2016 %D 2016 %R 10.1016/j.cattod.2015.08.011 %K Platinum %K Hollow metal nanoparticles %K Galvanic replacement %K Oxygen reduction reaction %K Proton exchange membrane fuel cell %K Durability %K Pt3CO/C %K Nanoparticles %K Carbon Corrosion %K Alloy Catalysts %K Surface Science %Z Physics [physics]Journal articles %X Hollow nanomaterials composed of a Pt-rich shell surrounding a central void have demonstrated promising electrocatalytic activity for the oxygen reduction reaction (ORR). However, their long-term stability remains understudied, and is the focus of the present paper. Here, we followed the temperature-dependent morphological and compositional trajectories of hollow PtNi/C nanoparticles during accelerated stress tests (AST) of interest for proton-exchange membrane fuel cells (PEMFC) applications. The combined physical, chemical and electrochemical results showed that: (i) the PtNi/C nanoparticles preserve a hollow nanostructure during accelerated stress testing at T=25 degrees C, but collapsed in real PEMFC operating conditions (solid electrolyte - T=80 degrees C), (ii) the dissolution of Ni atoms is drastically enhanced with an increase of the temperature, almost all Ni atoms being leached after the AST conducted in a single PEMFC, (iii) a lattice strain of ca. 0.4% persists in the aged hollow PtNi/C nanocatalysts, (iv) whatever the AST conditions, hollow PtNi/C nanocatalysts show improved ORR activity over solid Pt/C nanocatalysts of the same crystallite size. The catalytic enhancement is believed to result from the presence of subsurface vacancies in the dealloyed hollow PtNi/C nanoparticles. In a more global perspective, the present contribution emphasizes the crucial role of temperature on the stability of shape-controlled particles (far from their equilibrium shape). (C) 2015 Elsevier B.V. All rights reserved. %G English %L cea-01849433 %U https://cea.hal.science/cea-01849433 %~ CEA %~ UNIV-SAVOIE %~ UGA %~ CNRS %~ INPG %~ INAC-SP2M %~ DSM-INAC %~ LEPMI %~ INC-CNRS %~ CEA-DRF %~ IRIG %~ CEA-GRE %~ UGA-COMUE %~ USMB-COMUE %~ ANR %~ TEST2-HALCNRS