How to Determine the Core-Shell Nature in Bimetallic Catalyst Particles?

How to Determine the Core-Shell Nature in Bimetallic Catalyst Particles?

Westsson, E.E.
Koper, G.J.M.

Applied Sciences

ChemE/Chemical Engineering

2014-11-28

Nanometer-sized materials have significantly different chemical and physical properties compared to bulk material. However, these properties do not only depend on the elemental composition but also on the structure, shape, size and arrangement. Hence, it is not only of great importance to develop synthesis routes that enable control over the final structure but also characterization strategies that verify the exact nature of the nanoparticles obtained. Here, we consider the verification of contemporary synthesis strategies for the preparation of bimetallic core-shell particles in particular in relation to potential particle structures, such as partial absence of core, alloying and raspberry-like surface. It is discussed what properties must be investigated in order to fully confirm a covering, pin-hole free shell and which characterization techniques can provide such information. Not uncommonly, characterization strategies of core-shell particles rely heavily on visual imaging like transmission electron microscopy. The strengths and weaknesses of various techniques based on scattering, diffraction, transmission and absorption for investigating core-shell particles are discussed and, in particular, cases where structural ambiguities still remain will be highlighted. Our main conclusion is that for particles with extremely thin or mono-layered shells—i.e., structures outside the limitation of most imaging techniques—other strategies, not involving spectroscopy or imaging, are to be employed. We will provide a specific example of Fe-Pt core-shell particles prepared in bicontinuous microemulsion and point out the difficulties that arise in the characterization process of such particles.

core-shell
characterization
bimetallic catalysts
OA-Fund TU Delft

http://resolver.tudelft.nl/uuid:52a8b2ab-b8f3-41ea-bf06-cc3592ce04d1

https://doi.org/10.3390/catal4040375

MDPI

2073-4344

Catalysts, 4 (4), 2014

Institutional Repository

journal article

(c) 2014 This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.