Ensemble versus Local Restructuring of Core-shell Nickel-Cobalt Nanoparticles upon Oxidation and Reduction Cycles.

Autor: Carenco S; Sorbonne Université, CNRS, Collège de France, Laboratoire de Chimie de la Matière Condensée de Paris, 4 Place Jussieu, 75252, Paris, France., Bonifacio CS; Department of Chemical and Petroleum Engineering, University of Pittsburgh, 4200 Fifth Avenue, Pittsburgh, Pennsylvania, 15260, USA.; E.A. Fischione Instruments Inc., 9003 Corporate Circle, Export, PA, 15632, USA., Yang JC; Department of Chemical and Petroleum Engineering, University of Pittsburgh, 4200 Fifth Avenue, Pittsburgh, Pennsylvania, 15260, USA.; Department of Physics, University of Pittsburgh, 4200 Fifth Avenue, Pittsburgh, Pennsylvania, 15260, USA.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2018 Aug 14; Vol. 24 (46), pp. 12037-12043. Date of Electronic Publication: 2018 Jul 25.
DOI: 10.1002/chem.201802764
Abstrakt: Bimetallic nanoparticles are widely studied, for example in catalysis. However, possible restructuring in the environment of use, such as segregation or alloying, may occur. Taken individually, state-of-the-art analytical tools fail to give an overall picture of these transformations. This study combines an ensemble analysis (near-ambient-pressure X-ray photoelectron spectroscopy) with a local analysis (environmental transmission electron microscopy) to provide an in situ description of the restructuring of core-shell nickel-cobalt nanoparticles exposed to cycles of reduction and oxidation. It reveals a partial surface alloying accompanied by fragmentation of the shell into smaller clusters, which is not reversible. Beyond this case study, the methodology proposed here should be applicable in a broad range of studies dealing with the reactivity of mono- or bi-metallic metal nanoparticles.
(© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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