title: In Situ Microfocus Chemical Computed Tomography of the Composition of a Single Catalyst Particle During Hydrogenation of Nitrobenzene in the Liquid Phase.
abstract: Heterogeneous catalysis performed in the liquid phase is an important type of catalytic process which is rarely studied in situ. Using microfocus X-ray fluorescence and X-ray diffraction computed tomography (μ-XRF-CT, μ-XRD-CT) in combination with X-ray absorption near-edge spectroscopy (XANES), we have determined the active state of a Mo-promoted Pt/C catalyst (NanoSelect) for the liquid-phase hydrogenation of nitrobenzene under standard operating conditions. First, μ-XRF-CT and μ-XRD-CT reveal the active state of Pt catalyst to be reduced, noncrystalline, and evenly dispersed across the support surface. Second, imaging of the Pt and Mo distribution reveals they are highly stable on the support and not prone to leaching during the reaction. This study demonstrates the ability of chemical computed tomography to image the nature and spatial distribution of catalysts under reaction conditions.
authors.affiliation: Science Division, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxon, OX11 0DE (UK). stephen.price@diamond.ac.uk.
authors.forename: Stephen W T
authors.initials: SW
authors.lastname: Price
authors.affiliation: Science Division, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxon, OX11 0DE (UK).
authors.forename: Kalotina
authors.initials: K
authors.lastname: Geraki
authors.affiliation: Science Division, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxon, OX11 0DE (UK).
authors.forename: Konstantin
authors.initials: K
authors.lastname: Ignatyev
authors.affiliation: Catalysis Research GCC/PB, BASF Nederland B.V. Strijkviertel 67, 3454 ZG, De Meern (The Netherlands).
authors.forename: Peter T
authors.initials: PT
authors.lastname: Witte
authors.affiliation: UK Catalysis Hub, Research Complex at Harwell, Harwell Science and Innovation Campus, Harwell, Didcot, Oxon, OX11 0FA (UK). andrew.beale@ucl.ac.uk.|University College London, Department of Chemistry, 20 Gordon Street, London, WC1H 0AJ (UK). andrew.beale@ucl.ac.uk.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Beale
authors.affiliation: Science Division, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxon, OX11 0DE (UK).
authors.forename: J Fred W
authors.initials: JF
authors.lastname: Mosselmans
keywords: X-ray microspectroscopy; computed tomography; heterogeneous catalysis; liquid phase; supported catalysts