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Title: An in situ sample environment reaction cell for spatially resolved x-ray absorption spectroscopy studies of powders and small structured reactors

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 of 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 transmissionmore » 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
Authors:
; ; ;  [1] ; ; ;  [2] ;  [3]
  1. Division of Synchrotron Radiation Research, Lund University, Box 118, SE-221 00 Lund (Sweden)
  2. MAX IV Laboratory, Lund University, Box 118, SE-221 00 Lund (Sweden)
  3. Competence Centre for Catalysis, Chalmers University of Technology, SE-412 96 Göteborg (Sweden)
Publication Date:
OSTI Identifier:
22392403
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 86; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ABSORPTION; ABSORPTION SPECTROSCOPY; ALUMINIUM OXIDES; CARBON MONOXIDE; CATALYSTS; FLUORESCENCE; GAS FLOW; KEV RANGE 01-10; MASS SPECTROSCOPY; PELLETS; PERFORMANCE; STRUCTURE FUNCTIONS; X RADIATION; X-RAY DIFFRACTION; X-RAY SPECTROSCOPY