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Accueil du site > Séminaires > Séminaires 2014 > Ab-initio investigation of Transition-Metal oxides surfaces for catalytic applications

Mardi 11 février 2014-14:00

Ab-initio investigation of Transition-Metal oxides surfaces for catalytic applications

Bertrand SITAMTZE (Institut des Molecules et Materiaux du Mans, Université du Maine)

par Gabriel LeMarié - 11 février 2014

In recent years the interest for magnetic nanoparticles with specific properties has increased considerably. The first reason behind this is that the synthesis routes of such nanoparticles are improved on daily basis. This is the case for the polyol process that is being put in place for quite some times at the Laboratoire ITODYS of Université de Paris 7 [1]. Secondly, the as-prepared nanomaterials exhibit outstanding properties that allow them to be suitable for industrial applications. Among all transition-metal based nanomaterials, iron oxydes nanoparticles are biocompatible and therefore suitable for medical applications, especially in selective drug delivery process against diseases such as cancer [2].

The functionalization of the as-prepared nanoparticules plays a key role. However, the mechanism of interaction between the solid surface and its neighboring organic molecules is often unknown. A deep insight into this surface-molecules interaction would help in achieving specific targets such as monitoring the nanoparticles in terms of size, shape and most importantly the aggregation state. To achieve this goal, a multiscale approach is needed. Thus, ab-initio calculations turn out to be the first and fundamental step, thanks to the accuracy of the produced informations.

In this talk, we will present the advantages behind studying such materials by ab-initio calculations within the framework of heterogeneous catalysis. Considering the strongly correlated nature of these materials, we shall focus on the DFT+U method of accounting for electrons correlation. Hence, our recent results on cobalt oxide will be described in details [3], together with the interaction between CoO(001) surface and diethylene glycol molecules. In addition, a discussion on methods for investigating charge transfer between the solid surface and its ontop material is included.

References

[1] M. Artus, L. Ben Tahar, F. Herbst., L. S. Smiri, F. Villain., N. Yaacoub, J. M. Greneche, S. Ammar and F. Fievet, J. Phys. : Condens. Matt., 23(2011), 506001-506009

[2] F. R., R. Moresco and M. Masserini, J. Phys. D : Appl. Phys., 45 (2012) 073001 (12pp)

[3] B. Sitamtze Youmbi and F. Calvayrac, Surf. Sc., 621 (2014) 1-6

Post-scriptum :

contact : M. Dinh