Nous aurons le plaisir d’accueillir le Docteur Alexandre LEBON (Laboratoire de Chimie, Electrochimie Moléculaires et Chimie Analytique de l’Université de Bretagne Occidentale) le jeudi 30 mars 2023 à 14 h à l’auditorium. Il présentera un séminaire intitulé
Ab(d)soprtion in low dimensional systems examples with Hydrogen and Oxygen
This presentation is divided into three parts. The first two parts are related to the interaction of hydrogen in selected low dimensional systems. The last is concerned with the early oxidation step of a ZnMg nanoalloys.
In the first part I will display DFT calculations of H insertion within Pd-Pt nanoparticles of interest for the Preferential oxidation of CO. The way H inserts within the nanoparticles is rationalized with an analysis of absorption energies, geometry changes ; an electronic indicator is also used.
The second part will be devoted to the adsorption of molecular hydrogen on decorated monolayer systems like graphene nanoribbon or borophene. Computation of the binding energies, arrangement of molecular hydrogen and nature of the interaction of the molecule with the decorating atom and the surface are discussed. A model that incorporates pressure and temperature is then presented to give a realistic assessment of the gravimetric and volumetric storage capacities.
The last part is related to the building of clusters and nanoalloys by using the predictive power of a combined Empirical Potential-DFT approach. The computed putative global minima for the ZnN clusters and the nanoalloys Zn20-xMgx are examined as a function of their reactive properties. The attack of a corroding agent, here oxygen atoms, has been examined.