aarhus university peter nicolai ravnborg vennestrøm,b carlo...
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AU Aarhus University
Highlighted by in situ Simultaneous PXRD and XANES Casper Welzel Andersen,a Elisa Borfecchia,b,c Martin Bremholm,a Mads Ry Vogel Jørgensen,a,d
Peter Nicolai Ravnborg Vennestrøm,b Carlo Lamberti,c,e Lars Fahl Lundegaard,b & Bo Brummerstedt Iversena
aAarhus University, Aarhus, Denmark, e-mail: [email protected] – bHaldor Topsøe A/S, Kgs. Lyngby, Denmark cUniversity of Torino, Turin, Italy – dMAX IV, Lund, Sweden – eIRC “Smart Materials”, Southern Federal University, Rostov-on-Don, Russia
Casper Welzel Andersen
PhD student
Acknowledgements MB thanks the Villum Foundation
for funding. CL acknowledges
mega-grant of Ministry of Edu-
cation and Science of the Russian
Federation (14.Y26.31.0001). EB
acknowledges Innovation Fund
Denmark (Industrial postdoc n.
5190-00018B). We thank W. van
Beek for his help during beam
time on BM01B (now BM31) at
ESRF. CMC is a Center of
Excellence funded by the Danish
National Research Foundation
(DNRF93).
Redox-driven Migration of Cu Ions in Cu-CHA
Web: person.au.dk/cwa@inano
E-mail: [email protected]
Telephone: +45 87 15 53 45
Fax: +45 86 19 61 99
Mobile: +45 61 69 77 34
Center for Materials Crystallography
iNANO
Department of Chemistry
Aarhus University
DK-8000 Aarhus C
Denmark
B
A
A’
Measurement cycle
Time: ~5 min.
2D-PXRD + 4 • XANES
References [1] C. W. Andersen et al., IUCr-J 2014, 1,
382-386
[2] T. V. W. Janssens et al., ACS Catal. 2015, 5, 2832-2845
[3] C. W. Andersen et al., Angew. Chem. Int. Ed. 2017, doi:
10.1002/anie.201703808
[4] E. Borfecchia et al., Chem. Sci. 2015,
6, 548-563
The NOx challenge
BM31 @ ESRF
NH3-assisted selective catalytic reduction
Previous study, determining the
Crystallographic structure of Cu-CHA
O2 activation Heat in oxidative atmosphere
Cu → Cu2+
He activation Heat in inert atmosphere
Cu → Cu+
NH3-assisted
Selective Catalytic Reduction
Diffraction Average structure of unit cell
Probes whole of electron density
Cannot practically detect a
single electron
Absorption spectroscopy Average environment around
specific element
Probes specific absorption edge
Cannot directly detect structure
[2]
Experimental
O2 activation experiment
X-ray diffraction and
absorption spectroscopy in
same set-up
Controllable variables
Gas environment
Temperature
He activation experiment
Linear combination fit references
[3] DOI: 10.1002/anie.201703808
[3] DOI: 10.1002/anie.201703808
[3] DOI: 10.1002/anie.201703808
Website person.au.dk/cwa@inano
Andersen et al., IUCrJ 2014, 1, 382-386
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Cu2+
-fw 8R Dehydration region
Cu+-fw 6R Total Cu ( ICP)
Cu2+
-w Ow Max. Cu2+
in 6R
O2 activation experiment
Ow
/uc
Ow
/uc
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Cu2+
-fw 8R Dehydration region
Cu+-fw 6R Total Cu ( ICP)
Cu2+
-w Ow Max. Cu2+
in 6R
He activation experiment
(C)
(B)
(A)