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Title: A flexible gas flow reaction cell for in situ x-ray absorption spectroscopy studies

Abstract

A capillary-based sample environment with hot air blower and integrated gas system was developed at Diamond to conduct X-ray absorption spectroscopy (XAS) studies of materials under time-resolved, in situ conditions. The use of a hot air blower, operating in the temperature range of 298-1173 K, allows introduction of other techniques e.g. X-ray diffraction (XRD), Raman spectroscopy for combined techniques studies. The flexibility to use either quartz or Kapton capillaries allows users to perform XAS measurement at energies as low as 5600 eV. To demonstrate performance, time-resolved, in situ XAS results of Rh catalysts during the process of activation (Rh K-edge, Ce L{sub 3}-edge and Cr K-edge) and the study of mixed oxide membrane (La{sub 0.6}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3−δ}) under various partial oxygen pressure conditions are described.

Authors:
; ; ; ; ; ;  [1];  [2];  [3]
  1. Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Chilton, Oxfordshire, OX110DE (United Kingdom)
  2. UK Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, Chilton, Oxfordshire, OX110FA (United Kingdom)
  3. (United Kingdom)
Publication Date:
OSTI Identifier:
22608350
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1741; Journal Issue: 1; Conference: SRI2015: 12. international conference on synchrotron radiation instrumentation, New York, NY (United States), 6-10 Jul 2015; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION; ABSORPTION SPECTROSCOPY; CATALYSTS; COBALT COMPOUNDS; DIAMONDS; FLEXIBILITY; GAS FLOW; IRON COMPOUNDS; LANTHANUM COMPOUNDS; MEMBRANES; OXIDES; OXYGEN; RAMAN SPECTROSCOPY; STRONTIUM COMPOUNDS; TIME RESOLUTION; X RADIATION; X-RAY DIFFRACTION; X-RAY SPECTROSCOPY

Citation Formats

Kroner, Anna B., E-mail: anna.kroner@diamond.ac.uk, Gilbert, Martin, Duller, Graham, Cahill, Leo, Leicester, Peter, Woolliscroft, Richard, Shotton, Elizabeth J., Mohammed, Khaled M. H., and School of Chemistry, University of Southampton, Southampton, SO17 1BJ. A flexible gas flow reaction cell for in situ x-ray absorption spectroscopy studies. United States: N. p., 2016. Web. doi:10.1063/1.4952837.
Kroner, Anna B., E-mail: anna.kroner@diamond.ac.uk, Gilbert, Martin, Duller, Graham, Cahill, Leo, Leicester, Peter, Woolliscroft, Richard, Shotton, Elizabeth J., Mohammed, Khaled M. H., & School of Chemistry, University of Southampton, Southampton, SO17 1BJ. A flexible gas flow reaction cell for in situ x-ray absorption spectroscopy studies. United States. doi:10.1063/1.4952837.
Kroner, Anna B., E-mail: anna.kroner@diamond.ac.uk, Gilbert, Martin, Duller, Graham, Cahill, Leo, Leicester, Peter, Woolliscroft, Richard, Shotton, Elizabeth J., Mohammed, Khaled M. H., and School of Chemistry, University of Southampton, Southampton, SO17 1BJ. 2016. "A flexible gas flow reaction cell for in situ x-ray absorption spectroscopy studies". United States. doi:10.1063/1.4952837.
@article{osti_22608350,
title = {A flexible gas flow reaction cell for in situ x-ray absorption spectroscopy studies},
author = {Kroner, Anna B., E-mail: anna.kroner@diamond.ac.uk and Gilbert, Martin and Duller, Graham and Cahill, Leo and Leicester, Peter and Woolliscroft, Richard and Shotton, Elizabeth J. and Mohammed, Khaled M. H. and School of Chemistry, University of Southampton, Southampton, SO17 1BJ},
abstractNote = {A capillary-based sample environment with hot air blower and integrated gas system was developed at Diamond to conduct X-ray absorption spectroscopy (XAS) studies of materials under time-resolved, in situ conditions. The use of a hot air blower, operating in the temperature range of 298-1173 K, allows introduction of other techniques e.g. X-ray diffraction (XRD), Raman spectroscopy for combined techniques studies. The flexibility to use either quartz or Kapton capillaries allows users to perform XAS measurement at energies as low as 5600 eV. To demonstrate performance, time-resolved, in situ XAS results of Rh catalysts during the process of activation (Rh K-edge, Ce L{sub 3}-edge and Cr K-edge) and the study of mixed oxide membrane (La{sub 0.6}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3−δ}) under various partial oxygen pressure conditions are described.},
doi = {10.1063/1.4952837},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1741,
place = {United States},
year = 2016,
month = 7
}
  • An easy-to-use sample environment reaction cell for X-ray based in situ studies of powders and small structured samples, e.g., powder, pellet, and monolith catalysts, is described. The design of the cell allows for flexible use of appropriate X-ray transparent windows, shielding the sample from ambient conditions, such that incident X-ray energies as low as 3 keV can be used. Thus, in situ X-ray absorption spectroscopy (XAS) measurements in either transmission or fluorescence mode are facilitated. Total gas flows up to about 500 ml{sub n}/min can be fed while the sample temperature is accurately controlled (at least) in the range ofmore » 25–500 °C. The gas feed is composed by a versatile gas-mixing system and the effluent gas flow composition is monitored with mass spectrometry (MS). These systems are described briefly. Results from simultaneous XAS/MS measurements during oxidation of carbon monoxide over a 4% Pt/Al{sub 2}O{sub 3} powder catalyst are used to illustrate the system performance in terms of transmission XAS. Also, 2.2% Pd/Al{sub 2}O{sub 3} and 2% Ag − Al{sub 2}O{sub 3} powder catalysts have been used to demonstrate X-ray absorption near-edge structure (XANES) spectroscopy in fluorescence mode. Further, a 2% Pt/Al{sub 2}O{sub 3} monolith catalyst was used ex situ for transmission XANES. The reaction cell opens for facile studies of structure-function relationships for model as well as realistic catalysts both in the form of powders, small pellets, and coated or extruded monoliths at near realistic conditions. The applicability of the cell for X-ray diffraction measurements is discussed.« less
  • No abstract prepared.
  • X-ray absorption spectroscopy measurements of catalytic reactions have been instrumental in advancing the understanding of catalytic processes. These measurements require an in situ catalysis reaction cell with unique properties. Here we describe the design and initial operation of an in situ/operando catalysis reaction cell for transmission X-ray absorption spectroscopy measurements. The cell is designed: to be an ideal catalytic reactor with no mass transfer effects; to give the same conversion and selectivity under similar space velocities as standard laboratory micro-reactors; to be operational temperatures up to 600 {sup o}C and pressures up to 14 bar; to be X-ray transparent allowingmore » XAS measurement to be collected in transmission for all elements with Z {>=} 23 (vanadium K-edge at 5.5 keV); to measure the actual catalyst bed temperature; to not use o-ring seals, or water cooling; to be robust, compact, easy to assemble, and use, and relatively low cost to produce. The heart of the cell is fabricated from an X-ray transparent beryllium tube that forms a plug flow reactor. XAFS data recorded during the reduction of a Re/{gamma}-A{sub 2}O{sub 3} catalyst as a function of hydrogen pressure from 0.05 to 8 bar, and from a Pt-Sn/{gamma}-A{sub 2}O{sub 3} catalyst during n-heptane reforming are given as initial examples of the versatility of the reactor.« less
  • The design and initial operation of an in situ catalysis reaction cell for x-ray absorption spectroscopy measurements at high pressure is described. The design is based on an x-ray transparent tube fabricated from beryllium. This forms a true plug flow reactor for catalysis studies. The reactor is coupled to a portable microprocessor-controlled versatile feed system, and incorporates on-line analysis of reaction products. XAFS data recorded during the reduction of a NiRe/carbon catalyst at 4 bar are used to illustrate the performance of the reactor.
  • We present a novel in situ reaction cell for heterogeneous catalysis monitored in situ by x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray scattering (RIXS). The reaction can be carried out at a total pressure up to 1 atm, a regime that has not been accessible to comparable in situ techniques and thus closes the pressure gap to many industrial standard conditions. Two alternate catalyst geometries were tested: (A) a thin film evaporated directly onto an x-ray transparent membrane with a flowing reaction gas mixture behind it or (B) a powder placed behind both the membrane and a gap ofmore » flowing reaction gas mixture. To illustrate the working principle and feasibility of our reaction cell setup we have chosen ethylene epoxidation over a silver catalyst as a test case. The evolution of incorporated oxygen species was monitored by total electron/fluorescence yield O K-XAS as well as O K-RIXS, which is a powerful method to separate contributions from inequivalent sites. We find that our method can reliably detect transient species that exist during catalytic reaction conditions that are hardly accessible using other spectroscopic methods.« less