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Redox-Driven Migration of Copper Ions in the Cu-CHA Zeolite as Shown by the InSitu PXRD/XANES Technique

Andersen, Casper Welzel; Borfecchia, Elisa; Bremholm, Martin; Jørgensen, Mads Ry Vogel LU ; Vennestrøm, Peter Nicolai Ravnborg; Lamberti, Carlo; Lundegaard, Lars Fahl and Iversen, Bo Brummerstedt (2017) In Angewandte Chemie - International Edition
Abstract

Using quasi-simultaneous insitu PXRD and XANES, the direct correlation between the oxidation state of Cu ions in the commercially relevant deNOx NH3-SCR zeolite catalyst Cu-CHA and the Cu ion migration in the zeolitic pores was revealed during catalytic activation experiments. A comparison with recent reports further reveals the high sensitivity of the redox-active centers concerning heating rates, temperature, and gas environment during catalytic activation. Previously, Cu+ was confirmed present only in the 6R. Results verify a novel 8R monovalent Cu site, an eventually large Cu+ presence upon heating to high temperatures in oxidative conditions, and demonstrate the unique potential in... (More)

Using quasi-simultaneous insitu PXRD and XANES, the direct correlation between the oxidation state of Cu ions in the commercially relevant deNOx NH3-SCR zeolite catalyst Cu-CHA and the Cu ion migration in the zeolitic pores was revealed during catalytic activation experiments. A comparison with recent reports further reveals the high sensitivity of the redox-active centers concerning heating rates, temperature, and gas environment during catalytic activation. Previously, Cu+ was confirmed present only in the 6R. Results verify a novel 8R monovalent Cu site, an eventually large Cu+ presence upon heating to high temperatures in oxidative conditions, and demonstrate the unique potential in combining insitu PXRD and XANES techniques, with which both oxidation state and structural location of the redox-active centers in the zeolite framework could be tracked.

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author
organization
publishing date
type
Contribution to journal
publication status
in press
subject
keywords
Heterogeneous catalysis, Structure-activity relationships, X-ray absorption spectroscopy, X-ray diffraction, Zeolites
in
Angewandte Chemie - International Edition
publisher
John Wiley & Sons
external identifiers
  • scopus:85025464866
ISSN
1433-7851
DOI
10.1002/anie.201703808
language
English
LU publication?
yes
id
12b922eb-53a3-4a07-9dd5-05f3afd0f9bf
date added to LUP
2017-07-31 13:59:43
date last changed
2017-07-31 13:59:43
@article{12b922eb-53a3-4a07-9dd5-05f3afd0f9bf,
  abstract     = {<p>Using quasi-simultaneous insitu PXRD and XANES, the direct correlation between the oxidation state of Cu ions in the commercially relevant deNO<sub>x</sub> NH<sub>3</sub>-SCR zeolite catalyst Cu-CHA and the Cu ion migration in the zeolitic pores was revealed during catalytic activation experiments. A comparison with recent reports further reveals the high sensitivity of the redox-active centers concerning heating rates, temperature, and gas environment during catalytic activation. Previously, Cu<sup>+</sup> was confirmed present only in the 6R. Results verify a novel 8R monovalent Cu site, an eventually large Cu<sup>+</sup> presence upon heating to high temperatures in oxidative conditions, and demonstrate the unique potential in combining insitu PXRD and XANES techniques, with which both oxidation state and structural location of the redox-active centers in the zeolite framework could be tracked.</p>},
  author       = {Andersen, Casper Welzel and Borfecchia, Elisa and Bremholm, Martin and Jørgensen, Mads Ry Vogel and Vennestrøm, Peter Nicolai Ravnborg and Lamberti, Carlo and Lundegaard, Lars Fahl and Iversen, Bo Brummerstedt},
  issn         = {1433-7851},
  keyword      = {Heterogeneous catalysis,Structure-activity relationships,X-ray absorption spectroscopy,X-ray diffraction,Zeolites},
  language     = {eng},
  month        = {07},
  publisher    = {John Wiley & Sons},
  series       = {Angewandte Chemie - International Edition},
  title        = {Redox-Driven Migration of Copper Ions in the Cu-CHA Zeolite as Shown by the InSitu PXRD/XANES Technique},
  url          = {http://dx.doi.org/10.1002/anie.201703808},
  year         = {2017},
}