Effect of Different Face Centered Cubic Nanoparticle Distributions on Particle Size and Surface Area Determination: A Theoretical Study
Articolo
Data di Pubblicazione:
2014
Abstract:
Nanoparticles research represents one of the most active fields in science due to the importance of nanosized materials in a wide variety of applications. Their characterization needs the comparison of data coming from different experimental techniques, but the peculiar properties of the nanosystem that each technique points out are not always properly taken into account and misleading results have been often reported. In this work, we generated transmission electron microscopy like (TEM-like) data to predict the extended X-ray absorption fine structure (EXAFS) and chemisorption-like typical outputs as the average coordination numbers up to fourth shell of the particles distribution and the surface area. The aim of the simulations is to explore the dependence of the calculated average coordination number (ACN) and average dispersion (AD) values from each parameter characterizing a particle size distribution (PSD), as the mean diameter, the width, the shape, and the profile, and shows that a range of distributions is compatible with given values of ACN and AD. In this way, we have established a general method to properly take into account the above-mentioned parameters and to allow for an accurate analysis and comparison of results. Furthermore, it will be shown that unfavorable distribution shape makes the comparison among techniques critical and potentially misleading if performed with an oversimplified model of the PSD such as those using the average diameter only.
Tipologia CRIS:
03A-Articolo su Rivista
Keywords:
fcc lattice; dispersion; coordination number; EXAFS; Particle size distribution; TEM; palladium catalysts; Pd nanoparticles; metal nanoparticles; CO chemisorption; X-ray-absorption spectroscopy
Elenco autori:
Giovanni Agostini;Andrea Piovano;Luca Bertinetti;Riccardo Pellegrini;Giuseppe Leofanti;Elena Groppo;Carlo Lamberti
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