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: cwa@inano.au.dk – 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: cwa@inano.au.dk

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

0

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tive fra

ction

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c

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4

6

8

10

12

14

(C)

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

T (

°C)

(A)

(B)

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0 10 20 30 40 50 60 70 80 90

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Ow

/uc

T (

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2

4

6

8

Cu2+

-fw 8R Dehydration region

Cu+-fw 6R Total Cu ( ICP)

Cu2+

-w Ow Max. Cu2+

in 6R

He activation experiment

(C)

(B)

(A)