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Spectromètre EXAFS Rapide pour Cinétiques Chimiques (ROCK)

Action : Equipements d'excellence

N° de convention : 10-EQPX-0045

Informations générales

  • Référence projet : 10-EQPX-0045
  • RST : Valérie BRIOIS
  • Etablissement Coordinateur : Synchrotron Soleil
  • Région du projet : Île-de-France
  • Discipline : 2 - SMI
  • Aide allouée : 3 297 120 €
  • Date de début du projet : 22/02/2011
  • Date de fin du projet : 31/12/2019
  • Site web du projet : https://www.synchrotron-soleil.fr/fr/lignes-de-lumiere/rock
  • Mots clés : Catalysis; Energy Storage; time resoved XAS

Résumé du projet

The ROCK project (Rocking Optics for Chemical Kinetics) aims to build a state-of-the-art Quick-EXAFS beamline to assess the structure-activity relationship of complex materials used for catalysis and energy storage, from academic and industrial applications. Phase 1 (48 months) was the construction of the beamline based on 2 Quick-EXAFS monochromators, equipped with Si(111) and Si(220) crystals, for covering the 4-40 keV energy range. with a time resolution up to 20ms. A first cylindrically-bent toroidal mirror vertically collimates the beam at the entrance of monochromators and focuses it in the horizontal plane. Inside the experimental hutch, the table supporting samples can be set at different positions along the beam axis varying continuously the beam size from a few mm down to 400 µm. In addition, another mirror is cylindrically bent to adjust the vertical focusing of the beam from a few mm to 150 µm. The adjustable beam size allows varying the photon density on the sample (helpful for samples susceptible to radiation damage) while keeping the flux (and, consequently the time resolution performance) nearly constant. One of the unique capabilities of the beamline is to allow recording several absorption edges, even separated by thousands of eV, of an evolving material during a single operando experiment. The study of multimetallic samples takes full advantage of the unique complementary of both monochromators together with easy changing of mirror harmonic rejection properties. Dedicated cells for heterogeneous catalysisand for electrochemical cycling of batteries, are available. The beamline opened to users in March 2015 and has reached outstanding performances for operando studies. Current research, carried out in phase 2 of the project (03/2015-12/2016), deals with the improvement of catalysts for hydrodesulfurization, for production of H2 by ethanol steam reforming and materials for negative and positive electrodes for Li- and Na-ions batteries.

(L'auteur de ce résumé est le coordinateur du projet, qui est responsable du contenu de ce résumé. L'ANR décline par conséquent toute responsabilité quant à son contenu.)