title: X-ray spectroscopy for chemistry in the 2-4 keV energy regime at the XMaS beamline: ionic liquids, Rh and Pd catalysts in gas and liquid environments, and Cl contamination in γ-Al2O3.
abstract: The 2-4 keV energy range provides a rich window into many facets of materials science and chemistry. Within this window, P, S, Cl, K and Ca K-edges may be found along with the L-edges of industrially important elements from Y through to Sn. Yet, compared with those that cater for energies above ca. 4-5 keV, there are relatively few resources available for X-ray spectroscopy below these energies. In addition, in situ or operando studies become to varying degrees more challenging than at higher X-ray energies due to restrictions imposed by the lower energies of the X-rays upon the design and construction of appropriate sample environments. The XMaS beamline at the ESRF has recently made efforts to extend its operational energy range to include this softer end of the X-ray spectrum. In this report the resulting performance of this resource for X-ray spectroscopy is detailed with specific attention drawn to: understanding electrostatic and charge transfer effects at the S K-edge in ionic liquids; quantification of dilution limits at the Cl K- and Rh L3-edges and structural equilibria in solution; in vacuum deposition and reduction of [Rh(I)(CO)2Cl]2 to γ-Al2O3; contamination of γ-Al2O3 by Cl and its potential role in determining the chemical character of supported Rh catalysts; and the development of chlorinated Pd catalysts in `green' solvent systems. Sample environments thus far developed are also presented, characterized and their overall performance evaluated.
authors.affiliation: XMaS, UK CRG, ESRF, 71 Avenue des Martyrs, 38043 Grenoble, France.
authors.forename: Paul B J
authors.initials: PB
authors.lastname: Thompson
authors.affiliation: School of Chemistry, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Bao N
authors.initials: BN
authors.lastname: Nguyen
authors.affiliation: School of Chemistry, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Rachel
authors.initials: R
authors.lastname: Nicholls
authors.affiliation: School of Chemistry, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bourne
authors.affiliation: Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
authors.forename: John B
authors.initials: JB
authors.lastname: Brazier
authors.affiliation: Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
authors.forename: Kevin R J
authors.initials: KR
authors.lastname: Lovelock
authors.affiliation: XMaS, UK CRG, ESRF, 71 Avenue des Martyrs, 38043 Grenoble, France.
authors.forename: Simon D
authors.initials: SD
authors.lastname: Brown
authors.affiliation: XMaS, UK CRG, ESRF, 71 Avenue des Martyrs, 38043 Grenoble, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Wermeille
authors.affiliation: XMaS, UK CRG, ESRF, 71 Avenue des Martyrs, 38043 Grenoble, France.
authors.forename: Oier
authors.initials: O
authors.lastname: Bikondoa
authors.affiliation: Department of Physics, University of Liverpool, Oliver Lodge Laboratory, Liverpool L69 7ZE, UK.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Lucas
authors.affiliation: Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
authors.forename: Thomas P A
authors.initials: TP
authors.lastname: Hase
authors.affiliation: Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Newton
keywords: catalysts; in situ spectroscopy; ionic liquids; low-energy X-ray absorption spectroscopy