Topic: Elementary reaction dynamics: the abstraction  of atoms from metal surfaces

Dr. Pascal Larregaray

Fecha : Viernes 06 de diciembre de 2019

Hora : 12:00 m.

Aula : Q-202 (Sección Química)

Promovido por: Grupo de Investigación GICA

Abstract

The rationalization of elementary reactivity at surfaces is of prime importance to numerous natural and technological areas. From a fundamental point of view, the way the energy concomitant to any chemical reaction is distributed among the desorbing molecules degrees-of-freedom and the surface is not entirely pictured. Over the last few years, we have been developing reaction dynamics simulations to investigate this issue for the recombination of H2 and N2 resulting from atomic adsorbate abstraction by atom scattering off the W(100) and W(110) covered surfaces. Potential energy surfaces, built from density functional (DFT) theory calculations, have been used to simulate, within the framework of classical dynamics (including semi-classical corrections), the subpicosecond Eley- Rideal and Hot-Atom processes. The implementation of effective models to account for energy dissipation to surface phonons and electron-hole pair excitations, have allowed to rationalize the non-adidabatic dynamics of atom abstraction at metal surfaces. Such dissipation significantly affects the length scale over which reactivity occurs. Some examples [1-3] of this ongoing research will be here shown.

[1]-O. Galparsoro, R. Pétuya, H.F. Busnengo, J. I. Juaristi, C. Crespos, M. Alducin, and P. Larregaray, Phys. Chem. Chem. Phys. (2016) 18, 31378-31383

[2]- O.Galparsoro, R.Petuya, J.I.Juaristi, C.Crespos, M.Alducin, and P.Larregaray, J. Phys. Chem C. (2015) 119, 15434-15442

[3]- O. Galparsoro, H.F. Busnengo, J. I. Juaristi, C. Crespos, M. Alducin, and P. Larrégaray, J. Chem. Phys. (2017), doi : 10.1063/1.4997127

Information about the speaker

After graduating from the National Engineering School of Chemistry of Paris (Chimie Paris Tech) and the Paris 6 University, Pascal Larregaray completed a Ph.D. in Theoretical Chemistry in 2001 at the University of Bordeaux, on an analytical extension of Transition State Theory to describe product state distributions. After his PhD, he stayed one year a post-doctoral fellow at Concordia University (Montreal, Canada) working on the collision induced dissociation of metal cluster as well as the reactivity of small species of atmospheric relevance. He then moved as an assistant to the Ecole Polytechnique Federale de Lausanne (Switzerland) to investigate the ultrafast dynamics of electronic bubble formation in supercritical fluids and quantum solids. In 2004, he was appointed as a CNRS researcher in the theoretical chemistry group of the Institute for Molecular Science (Bordeaux) to work on the elementary reaction dynamics of gas-phase and gas-surface processes. He got the accreditation to supervise researches in 2012, and was appointed as CNRS research director in 2016. From 2016, he is the Theoretical Chemistry group leader and the coordinator of the Transborder Joint Laboratory with the University of the Basque Country and the Donostia International Physics Center.