par Barroo, Cédric 
;De Decker, Yannick ;Devred, François ;Visart de Bocarmé, Thierry ;Kruse, Norbert
Référence Dynamics Days Europe (33: 2013-06-03->07: Madrid, Espagne)
Publication Non publié, 2013-06-04
;De Decker, Yannick ;Devred, François ;Visart de Bocarmé, Thierry ;Kruse, Norbert Référence Dynamics Days Europe (33: 2013-06-03->07: Madrid, Espagne)
Publication Non publié, 2013-06-04
Communication à un colloque
| Résumé : | Many non-equilibrium reactions take place in very small systems: reaction in cells, micelles, on catalysts, etc. Probing the dynamics of reactions at such a small scale can be challenging. The Field Emission Microscope (FEM) is a technique that makes it possible to image, in real time, a catalytic process taking place at the surface of model catalysts. Such systems can be kept out of equilibrium by a continuous supply of gas reactants to the surface of the catalyst [1]. This may lead to a time symmetry breaking in the products formation [2], which often manifests itself through the emergence of highly non-linear dynamics. The study of those non-linear dynamics at the nanoscale is achieved by a careful analysis of the brightness signal. In this contribution, we show how the dynamical attractors and the phase space dynamics of such reactive systems could be reconstructed from experimental time series, in the case of NO2 reduction on Pt field emitter tips. Periodic self-sustained oscillations could be linked to a limit cycle which, because of the spontaneous fluctuations induced by the system’s small size, actually defines a “stochastic crater” on the top and slopes of which dynamical trajectories can develop. This underlying structure persists even for very small systems, i.e. for parts of the system being as small as 200 Ų. |
