ROCK: A Beamline Tailored for Catalysis and Energy-Related Materials from ms Time Resolution to µm Spatial Resolution

Assessing the structure-activity relationship in materials used as catalysts or for energy storage is a major challenge in order to provide efficiency, durability, clean processes and sustainable energy.Xray Absorption Spectroscopy (XAS) is a widely used technique to this aim, as it can provide structural and electronic information about the active elements of these materials.Many XAS beamlines have improved their performances to provide time-resolved information about evolving materials under real working conditions.To this end, Quick-EXAFS (QEXAFS) monochromators were installed at SOLEIL synchrotron on the SAMBA beamline in 2009 [1].The excellent performances for operando studies of heterogeneous catalysts achieved on SAMBA [2] were very attractive for the scientific community, although the SAMBA's optical layout was optimized for its sagitally-focusing doublecrystal monochromator and could not offer more than 10 11 ph/s flux at the best at the sample position when using the QEXAFS ones.Based on the experience gained on SAMBA, the construction of a new beamline dedicated and optimized for the QEXAFS monochromators was decided and granted in 2011 by the French Agence Nationale de la Recherche in the framework of the national "Investissements d'Avenir" program (ANR-10-EQX-45-01).In order to propose a beamline tailored for operando characterization of catalytic and energy related materials, both experts from the synchrotron world and from the scientific domains were gathered from the start of the project.The consortium, leaded by SOLEIL, involved three major French scientific actors of the heterogeneous catalysis and materials for the energy communities: the