Ivan Yordanov highlights

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Transcript of Ivan Yordanov highlights

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Content

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Aims

State of the art

Pt and Cu clusters in nanosized BEA zeolite: γ-irradiation and thermal reduction

Pt clusters in BEA zeolite: plasma treatment

Preparation of Cu doped nanosized LTA zeolite – in situ incorporation

Conclusions

3

Aims

I. Synthesis of nanosized porous materials

- BEA & LTA types zeolite frameworks - crystal size - 10-500 nm

II. Preparation of metal (Me) contain molecular sieves

- Via two step approach: ion exchange follow by

= γ-irradiation

= plasma treatment

= thermal reduction

- Via one step approach using metal contains template

III. Preparation of metal doped thin porous films

IV. Me clusters in porous host for sensor application

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State of the art: molecular sieves

Molecular sieves are porous solids contain channels system

run through the entire particle, interconnecting the cavities and

terminating at the particle surface.

Zeolite membrane for gas separation

5

State of the art: zeolites

Zeolites are crystalline microporous aluminosilicates with a three-dimensional framework structure that forms regular channel system with molecular dimensions running throughout the zeolite crystals.

The zeolite framework is consisting from corner sharing SiO4 and AlO4 tetrahedra

Extraframework counter cations which are under-coordinated by the framework

Zeolite A type LTA structure Zeolite Beta type BEA structure

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State of the art: approaches for metal doping

Building nanomaterials

1. Top-Down

Για να καταλάβουμε τα πολλά και τα μεγάλα πρέπει να κατανοήσουμε πρώτα τα μικρά To understand the very large, we must understand the very small Δημόκριτος-Democritus

2. Bottom-Up

The glass appears green in daylight (reflected light), but red when light is transmitted from the inside of the vessel.

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Cluster size and location in porous frameworks

Small clusters containing below 4 nuclearity located in the small cage or side pockets of the zeolites

Low nuclearity metal cluster ( < 40 nuclearity) – situated in the zeolite cages or in the intersection spaces Metal clusters with more than 40 nuclearity, located in the channels or on the particle surface

Examples: Pt and Ir in sodalite cage in Faujasites

Super-cage in Faujasites BEA zeolites

Pt clusters in LTL

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Approaches for preparation of Me doped …

Reducing agents

chemical reduction / γ-irradiation

Impregnation of zeolite frameworks

Adsorption and decomposition of zerovalent metal compounds

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Approaches for preparation of Me doped …

Reducing agents

chemical reduction / γ-irradiation

Preparation of metal clusters in ion-exchanged zeolites

In-situ incorporation of metals in zeolite matrixes

(CH3)4N+ & [Cu(EDTA)]2-

into LTA framework

Initial colloidal suspension

Hydrothermal

synthesis

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Pt clusters in Beta zeolite: BEA zeolite framework…

BEA type zeolite structure

Aperture of the straight channels 6.6 x 7.1 Å – directions [100] and [010] Tortuous channel with aperture of 5.6 x 5.6 Å –in direction [001]

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Synthesis of nanosized BEA type crystals

Initial precursor suspension: 7.5 (TEA)2O*: 1 Al2O3**: 25S iO2

***: 375 H2O

Aged and hydrothermally treated: 3 days at RT followed by 72 h at 373 K

Purified and ion-exchanged: BEA zeolite crystals have Si/Al = 14 and 0.75 wt.% Pt2+

(TEA)2O* - tetraethyammonium hydroxide, Al2O3 **- aluminum tri- sec-butoxide and SiO2**- fumed silica

10 20 30 40 50

BEA-Pt[(NH3)

4]2+

BEA-pure

BEA-C-ICSD-416768

BEA-B-ICSD-160441

BEA-B-ICSD-153254

Inte

nsity [a

.u.]

2[deg], CuK

BEA-A-ICSD-153253

10 20 30 40 50

BEA-pure-100 nm

BEA-pure-10 nm

Inte

nsity [a

.u.]

2 [deg], CuK

Sample FWHM[21.45°2θ, (013)], [rad] L, [nm] FWHM[22.47°2θ, (031)], [rad] L, [nm]

BEA-pure-10 0.01375 10.7 0.01186 12.5

BEA-pure-100 0.01476 10 0.00623 23.6

Powder X-Ray Diffraction Pattern recorded in Debye-Scherrer Geometry

I. Yordanov, R. Knoerr, V. De Waele, P. Bazin, S. Thomas, M. Rivallan, L. Lakiss, T. Metzger; S. Mintova, Elucidation on Pt Clusters in the Micropores of Zeolite Nanoparticles Assembled in Thin Films, J. Phys. Chem. C 2010, 114, (49), 20974-20982,

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PSD and stability of BEA colloidal suspensions

10 100 1000

BEA-Pt-1000

BEA-Pt-300

Colloidal suspension of BEA-Pt2+

Washed BEA crystal stabilized in water

Sca

tte

rin

g I

nte

nsity [

a.u

.]

Particle size d, [nm]

As prepared suspension of BEA

Dynamic Light Scattering

Particle size distribution

-150 -100 -50 0 50 100 150

BEA-Pt-1000

BEA-Pt-300

Colloidal suspension of BEA-Pt2+

Washed BEA crystals stabilized in water

Inte

nsity [

a.u

.]-potential [mV]

As prepared suspension of BEA

Stability of zeolite suspensions

ζ – potentiel values

Hydrodynamic diameter: 25 – 50 nm ζ - potential value: from -50 to -35 mV

No change of the PSD and ζ-potentiels during post–synthesis treatments

I. Yordanov, R. Knoerr, V. De Waele, P. Bazin, S. Thomas, M. Rivallan, L. Lakiss, T. Metzger; S. Mintova, Elucidation on Pt Clusters in the Micropores of Zeolite Nanoparticles Assembled in Thin Films, J. Phys. Chem. C 2010, 114, (49), 20974-20982,

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Preparation of Pt clusters via γ-radiolysis

200 300 400 500 600 700 8000.0

0.5

1.0

1.5

2.0

300 400 500

0

1

0 5 10

gfedc

b

Dose [kGy]Wavelength [nm]

Ab

so

rbe

nce

[/c

m]

Wavelength [nm]

a

d

c

b

260

249

Ab

so

rbe

nce

[/c

m]

Pt plasmon band at 240-260 nm due to formed Ptn

0 clusters

UV-vis spectra of Pt-clusters

n

mm

aq

aq

aq

h

MMnM

MMe

MMM

MMe

OHOHHOHeOH

2

0

)1(

2

0

0

22

**

32

I. Yordanov, R. Knoerr, V. De Waele, P. Bazin, S. Thomas, M. Rivallan, L. Lakiss, T. Metzger; S. Mintova, Elucidation on Pt Clusters in the Micropores of Zeolite Nanoparticles Assembled in Thin Films, J. Phys. Chem. C 2010, 114, (49), 20974-20982,

200 300 400 500 600 700 8000.0

0.5

1.0

1.5

2.0

300 400 500

0

1

0 5 10

gfedc

b

Dose [kGy]Wavelength [nm]

Ab

so

rbe

nce

[/c

m]

Wavelength [nm]

a

d

c

b

260

249

Ab

so

rbe

nce

[/c

m]

15

Pt clusters in BEA zeolite: HRTEM study

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

0

20

40

60

80

100

120

AlSi

Cu

Pt

Pt Pt

Inte

nsity [

Co

un

ts]

Energy [keV]

BEA-Pt-300

Al

SiCu

Pt

Pt

Inte

nsity [

Co

un

ts]

Energy [keV]

Pt

BEA-Pt-1000

Scale bar = 10 nm

Average diameter of BEA zeolite crystals: 10 nm No Pt cluster outside of the BEA crystals Pt clusters are situated in the BEA channels Size of Pt clusters: 1-2 nm dPt(220) =0.23 nm dBEA(100) =1.26 nm

I. Yordanov, R. Knoerr, V. De Waele, P. Bazin, S. Thomas, M. Rivallan, L. Lakiss, T. Metzger, S. Mintova, Elucidation on Pt Clusters in the Micropores of Zeolite Nanoparticles Assembled in Thin Films, J. Phys. Chem. C 2010, 114, (49), 20974-20982,

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1. Coating suspension: -1 wt. % zeolite suspension -co-solvant: ethanol -binder: 0.7 wt.% methyl cellulose

2. Spin coating deposition:

3. Conditions of spin coating: 1st layer 60 s at 4000 rpm 2nd – 4th layers 30 s at 1600 rpm and 5th – 6th layers 60 s at 3600 rpm

All films contain 6 layers 500 nm

500 nm

500 nm

Preparation of zeolite films

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Grazing-Incidence X-Ray Diffraction

0.0 0.1 0.2 0.3 0.4 0.5 0.61

10

100

1000

Incident angle , [deg]

Pe

ne

tra

tio

n d

ep

th

, [A

ng

str

om

]

Principal scheme: GI-XRD geometry

Characterization of films at different penetration depths Λ = f (Q)

500 nm

'

i

''

i

'

f''

f

1Im

ZQ

I. Yordanov, R. Knoerr, V. De Waele, P. Bazin, S. Thomas, M. Rivallan, L. Lakiss, T. Metzger, S. Mintova, Elucidation on Pt Clusters in the Micropores of Zeolite Nanoparticles Assembled in Thin Films, J. Phys. Chem. C 2010, 114, (49), 20974-20982,

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Pt-clusters in BEA films: GI-XRD patterns

BEA-Pt film: 1000 Gy

27 37 47 57 67 77

i=0.1°

i=0.05°

Inte

ns

ity

[a

.u.]

2 [deg]

Pt(111)

Pt(200) Pt(220)

5 6 7 8 9

Inte

ns

ity

[a

.u.]

2 [deg]

27 37 47 57 67 77

Pt(220)Pt(200)

Pt(111)

i=0.1°

i=0.05°

Inte

ns

ity

[a

.u.]

2 [deg]

Pt-BEA films: 300 Gy

Small clusters Big clusters

λ hν

d θ θ

λ = 2dsinθ

Scherrer’s equation:

cos.

.

FWHM

KL

Average cluster size: 1-2 nm

I. Yordanov, R. Knoerr, V. De Waele, P. Bazin, S. Thomas, M. Rivallan, L. Lakiss, T. Metzger, S. Mintova, Elucidation on Pt Clusters in the Micropores of Zeolite Nanoparticles Assembled in Thin Films, J. Phys. Chem. C 2010, 114, (49), 20974-20982,

20

Ellipsometry investigations

200 300 400 500 600 700 800 9001.2

1.3

1.4

1.5

1.6

1.7

1.8

Ind

ex

of

refr

ac

tio

n

Wavelength [nm]

Principal scheme: Ellipsometry

Film thickness: 200 - 500 nm Increase of the density of the materials leads to higher values of index refractive index

200 300 400 500 600 700 800 9000

10

20

30

40

50

60

70

80

90

75°

,

[d

eg

]

Wavelength , [nm]

65°

Cauchy modelling

Optical properties

Beta

Pt-Beta-300

Pt-Beta-1000

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Preparation of Pt clusters in BEA zeolite by cold plasma

3750

3500

3250

3000

2750

2500

, [cm-1]

t, [s

ec]

25

0

A

BEA-Pt-2+ in O2 Before plasma treatment

After plasma treatment

3750

3500

3250

3000

2750

2500

AHC

25 t, [sec

]

0

A

, [cm-1]

In Situ FTIR study of TEA decomposition from BEA zeolite

M. Rivallan, I. Yordanov, S. Thomas, S. Mintova, F. Thibault-Starzyk, Plasma Synthesis of highly dispersed metal clusters confained in nanosized zeolites. ChemCatChem 2010, 2, (9), 1074-1078

BEA-Pt-2+ in N2

The CH3- stretching modes at 3100 - 2800 cm-1 originating from the TEA+ -ion vanishes due to plasma decomposition of TEA+ -ion.

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Pt clusters in BEA zeolite for CO sensing

10 20 30 40 50

BEA pure

BEA-Pt2+

Inte

ns

ity

[a

.u.]

2deg], CuK

BEA-Pt

Pt

Stability of Pt clusters and Beta host

2150 2125 2100 2075 2050 2025

, [cm-1]

0,02 a.u.

A

CO chemisorbed on Pt-BEA BEA-Pt sample treated in O2 plasma

The band at 2086 cm-1 of Pt-CO increases with the concentration of CO

Global process: from template removal to formation of Pt0

M. Rivallan, I. Yordanov, S. Thomas, S. Mintova, F. Thibault-Starzyk, Plasma Synthesis of highly dispersed metal clusters confained in nanosized zeolites. ChemCatChem 2010, 2, (9), 1074-1078,

Bragg’s reflections at 39.8° and 46.3 ° 2θ from Pt0 with hkl – values (111) and (002)

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Copper clusters in BEA zeolite

10 20 30 40 50

Inte

ns

ity

[a

.u.]

2 [deg], Cu K

BEA pure

BEA-Cu2+

Crystallinity of the sample

10 100 1000

Sc

ate

rin

g I

nte

ns

ity

[a

.u.]

Particle size d, [nm]

BEA pure

BEA-Cu2+

Particle size distribution

(TEA)2O* - tetraethyammonium hydroxide, Al2O3 ** -aluminum tri- sec-butoxide and SiO2 **- fumed silica

BEA-Cu2+ BEA-Cu-species

Thermal treatment at 723 K for 6 h

Initial precursor suspension: 7(TEA)2O*:1.9Al2O3**:100SiO2

***: 1000H2O

Aged and hydrothermally treated: 27 h at RT followed by 72 h at 373 K

Purified and ion-exchanged: BEA zeolite crystals have Si/Al = 14 and 1.74 wt.% Cu2+

24

i r

21002125

21502175

2200

Ar

Ar

Ar + CO

Time

Wavenumber [cm-1]

0.2 a.u.

Cu +

- CO - 2157 cm -1

Cu+ -

(CO) 2 -

2177

cm-1

500 nm

CO chemisorbed on Cu species

Cu-doped zeolite Beta nanoparticles have good sensing response to CO.

The solid films Cu-BEA/QCM can be used for sensing applications.

Thin film on QCM

Spin coating deposition

Coating suspension

Thin film on QCM from zeolite Beta nanocrystals

doped with Cu species

Operando DRIFTS study Gas composition: Lean flow: Ar Rich flow: 4000 ppm CO Total flow = 10 ml.min-1 Gas vector: Ar

IR bands: 2157 cm-1 - Cu+ - CO

2177 cm-1 - Cu+(CO)2

Cu doped zeolite film on QCM for gas sensing

25

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Structure of zeolite Linde A

β – cage (sodalite cage) - [4866]

α – cage - [4126886]

The cages of zeolite A can host different cations such as Na+, K+, Ca+, Cs+, NH4

+ etc.

LTA zeolite framework has 3D pore structure with pores running perpendicular each other in x, y and z planes

4.2 Å D4R

O

Na+

Na+

O

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Synthesis of zeolite A crystals

Sample name Molar ratio Template T,°C t,h dH,nm

tf-Na-LTA 2.5Na2O*:1.5Al2O3***:2SiO2

***:110H2O template free 60 24 410

Na-TMA-LTA 13.5(TMA)2O:1.8Al2O3**:11.3SiO2

**:0.29Na2O*:763H2O [(CH3)4N]+ 70 24 170

Cu-EDTA-TMA-LTA 13.4(TMA)2O:1.7Al2O3:11.2SiO2:0.25[Cu(EDTA)2]2-:5NH3:650H2O [(CH3)4N]+2[Cu(EDTA)]2- 70 72 280

Chemical composition of the initial systems and conditions of synthesis

LTA zeolite crystals have been separated from the mother liquid by double centrifugation at 13 000 rpm for 15 mins. After each cycle the zeolite crystals were re-dispersed in Milli-Q water using the ultrasonic bath for 1h in ice.

Na2O* - NaOH, (TMA)2O - tetramethylammonium hydroxide, Al2O3**- Al(O-i-Pr)3, Al2O3

*** - sodium aluminate, SiO2** - LUDOX SM-30 SiO2

*** - sodium silicate

[(CH3)4N]+-ion ~6.4 Å

[Cu(EDTA)]2—complex ~7.8 Å

β – cage (sodalite cage)

Cage inner space ~6.5 Å α – cage

Cage inner space ~11.4 Å

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PXRD data

Powder X-Ray Diffraction Pattern recorded in Bragg-Brentano Geometry

Experimental XRD patterns contain all typical for LTA framework Bragg’s reflections at: 2θ = 7.2 ° => (200); 2θ = 10.2 ° => (220); 2θ = 12.5 ° => (222); 2θ = 24.2 ° => (622)

Cu2O Bragg’s reflections at: 2θ = 36.5 ° => (111) and 2θ = 42.4 ° => (002) - have not been observed

5 10 15 20 25 30 35 40 45 50

29.152

Inte

nsity /

a.u

.

2deg, Cu K

Simulated PXRD pattern

tf-Na-LTA

Na-TMA-LTA

Cu-EDTA-TMA-LTA

17.202

200

220

222

622

=> L≈380nm

Scherrer’s equation

𝑳 = 𝑲 𝝀

𝑭𝑾𝑯𝑴 𝒄𝒐𝒔𝜽

200 nm

23.6 23.8 24.0 24.2 24.4 24.6 24.8

Inte

nsity /

a.u

.

2deg, Cu K

Cu-EDTA-TMA-LTA

Pseudo-Voigt fitting function

FWHM = 3.648x10-3 rad

2= 24.18 deg

(622)

I. Yordanov, I. Karatchevtseva, H. Chevreau, M. Avdeev, R. Holmes, G. Thorogood, T. Hanley, One-step approach for synthesis of nanosized Cu-doped zeolite A crystals using the Cu-EDTA-complex. Micropor. Mesopor. Mat. 2014, 199, pp 18–28

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In situ PXRD & TG-DTA data sets

10 20 30 40 50 60 70 80

29

.152

Te

mp

era

ture

/ °

C

Inte

nsity / a

.u.

2deg, Cu K

17

.202

35

100

125

150

175

200

250

300

450

35

15 20 25 30 35

Te

mp

era

ture

/ °

C

Inte

nsity / a

.u.

2deg, Cu K

35

100

125

150

175

200

250

300

450

35

25

20

15

10

5

0500

400

300

200

100

0

24.46

24.48

24.50

24.52

24.54

24.56

24.58

24.60

450250175

Temperature / °C

Ce

ll P

ara

me

ter

a /إ

Time / h

ours

24

.47

64

9

35

24

.60

31

8

125

24

.60

03

2

24

.60

42

0

24

.53

90

4

24

.53

70

3

35

co

ole

d d

ow

n

Temperature-dependent in situ XRD data sets

I. Yordanov, I. Karatchevtseva, H. Chevreau, M. Avdeev, R. Holmes, G. Thorogood, T. Hanley, One-step approach for synthesis of nanosized Cu-doped zeolite A crystals using the Cu-EDTA-complex. Micropor. Mesopor. Mat. 2014, 199, pp 18–28

Cell parameter a estimated from X-ray data sets, as a function of temperature

Zeolite cell parameter a : - in the range 35 -125 °C increases due to a thermal

expansion of both zeolite framework and occluded organic template

- in the range 125 -250 °C is nearly constant - at 175 ° C contracts due to a release of H2O from the

framework. - in the range 250- 450 °C decreases due to removal of

H2O and thermal decomposition of various organic species.

- at 35 ° C (cooled down) is higher in comparison to the initial value due to trapped carbonaceous char.

Low-intensity and very broad Bragg reflections were observed between 17.20 ° and 29.15 ° 2θ. The intensity of the additional reflections in all patterns between 35 ° C and 175 ° C decreases with increasing the temperature.

30 30

TG-DTA data

I. Yordanov, I. Karatchevtseva, H. Chevreau, M. Avdeev, R. Holmes, G. Thorogood, T. Hanley, One-step approach for synthesis of nanosized Cu-doped zeolite A crystals using the Cu-EDTA-complex. Micropor. Mesopor. Mat. 2014, 199, pp 18–28

Cell parameter a estimated from X-ray data sets, as a function of temperature

100 200 300 400 500 600 700 800 900 1000

60

70

80

90

100

We

igh

t ch

an

ge

/ %

Tempareture / °C

-20

0

20

40

60

80

100

DT

A /

V

-2.0

-1.5

-1.0

-0.5

0.0

De

riva

tive

We

igh

t / %

.(°C

)-1

Endo

Exo

C)

TG-DTA data

< 100 °C - releasing of unbound or free H2O 175 - enlarged pore apertures allow H2O molecules to escape from the cages. 100 - 200 °C - releasing of chemically bound H2O 250 - 420 °C - the thermal decomposition of [Cu(EDTA)]2- -ion 450 -500 °C - thermal decomposition of TMA+ -ion. >500 ° C - slow ongoing mass-loss.

35 - 250 ° C - thermal expansion of both zeolite framework and template 175 ° C - contraction of the a due to a release of H2O from framework 250- 450 °C - a decreases due to removal of H2O and thermal decomposition of various organic species.

25

20

15

10

5

0500

400

300

200

100

0

24.46

24.48

24.50

24.52

24.54

24.56

24.58

24.60

450250175

Temperature / °C

Ce

ll P

ara

me

ter

a /إ

Time / h

ours

24

.47

64

9

35

24

.60

31

8

125

24

.60

03

2

24

.60

42

0

24

.53

90

4

24

.53

70

3

35

co

ole

d d

ow

n

31

SEM - EDX data

200 nm

0 2 4 6 8 10

0

1000

2000

3000

4000

5000

6000

7000

8000Na K

Cu, K

C K

O K

Na K

Cu, K

Inte

nsity / C

ou

nts

Energy / keV

Si K

Al K

Cu, K

Si K

Al K

0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

0

1000

2000

3000

4000

5000

6000

7000

8000

Inte

nsit

y / C

ou

nts

Energy / keV

Energy-dispersive X-ray spectrum

Energy-dispersive X-ray analysis confirmed the presence of Cu2+-ion in the Cu-EDTA-TMA-LTA zeolite nano-crystals with the Cu peaks evident at 8.1 keV (Kα1) and 0.93 keV (Kβ1)

SEM secondary micrograph

Cu-EDTA-TMA-LTA zeolite nano-crystals are predominantly spherical in shape with the crystal size in the region 170-280 nm.

I. Yordanov, I. Karatchevtseva, H. Chevreau, M. Avdeev, R. Holmes, G. Thorogood, T. Hanley, One-step approach for synthesis of nanosized Cu-doped zeolite A crystals using the Cu-EDTA-complex. Micropor. Mesopor. Mat. 2014, 199, pp 18–28

32

ESR spectrum

The asymmetric ESR spectrum suggests that the ligands (the O-atoms from COO--groups) along the z axis are much more screened from the Cu2+ ion than are the four radial ligands (2 N- and 2 O-atoms from chelate ring) along the x and y axes.

2500 3000 3500 4000

500 Gauss

X-band magnetic field strength / Gauss

T

g = 2.08

gII = 2.30

AII = 150

Cu2+ ion - (d9 – t62ge

1g)

O

N

Cu[EDTA]2- -complex LTA zeolite framework

I. Yordanov, I. Karatchevtseva, H. Chevreau, M. Avdeev, R. Holmes, G. Thorogood, T. Hanley, One-step approach for synthesis of nanosized Cu-doped zeolite A crystals using the Cu-EDTA-complex. Micropor. Mesopor. Mat. 2014, 199, pp 18–28

33

FTIR spectra

The IR spectroscopy clearly shows the presence of bands due to bonding of copper to nitrogen and oxygen atoms from the EDTA4--ion, which is an indication of existence of a [Cu(EDTA)]2--complex in the LTA zeolite framework.

I. Yordanov, I. Karatchevtseva, H. Chevreau, M. Avdeev, R. Holmes, G. Thorogood, T. Hanley, One-step approach for synthesis of nanosized Cu-doped zeolite A crystals using the Cu-EDTA-complex. Micropor. Mesopor. Mat. 2014, 199, pp 18–28

Cu2+ ion O

N

Cu[EDTA]2- -complex

IR bands: 1635 cm-1 – COO- ··· Cu2+ 1618 cm-1 – COO- ··· Cu2+ 1109 cm-1 – C–N··· Cu2+

1100-800 cm-1 – stretching vibrations in LTA framework 1640-1620 cm-1 –νas-COO- 1440-1330 cm-1 –νs-COO- 1107 cm-1 – C-N stretching vibrations – C-N-Cu

1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700

3500 3000 2500

1109

12951340

14151

485 690

838

13501385

1618

Wavenumber / cm-1

tf-Na-LTA

Na-TMA-LTA

Cu-EDTA-TMA-LTA

1635

Wavenumber / cm-1

ν as -

CO

O- ··

· Cu

2+

- ν a

s – C

H3

- ν s

– C

H3

(CH3)4N+

- ν s

- C

OO

- -

ν –

C –

O

- sc

is. v

ib. -

CO

O-

- w

ag. v

ib. -

CO

O-

- w

ag. v

ib. –

CH

2

- tw

ist.

– C

H2

- st

retc

h. –

C–N

··· C

u2

+ CH2

34

Raman spectra

I. Yordanov, I. Karatchevtseva, H. Chevreau, M. Avdeev, R. Holmes, G. Thorogood, T. Hanley, One-step approach for synthesis of nanosized Cu-doped zeolite A crystals using the Cu-EDTA-complex. Micropor. Mesopor. Mat. 2014, 199, pp 18–28

1600 1400 1200 1000 800 600 400 200

63

06

701

05

012

70

14

65

14

53

16

75 14

15

49

04

58

Na-TMA-LTA

Raman shift / cm-1

tf-Na-LTA

Cu-EDTA-TMA-LTA

10

18

Cu2+ ion O

N

Cu[EDTA]2- -complex

Raman bands: 1018 cm-1 – C – C 458 cm-1 – Cu – N 630 cm-1 – Cu – O

- st

retc

h. –

C –

C

- C

– N

– d

efo

rm. +

Cu

– N

– s

. str

etch

- ν a

s - C

OO

-

- ν a

s – C

H3

- sc

is. v

ib. –

CH

2

- tw

ist.

– C

H2

- ν a

s – C

– N

- ν s

– C

– N

-

stre

tch

. – C

u –

O

- D

4R

I458/I490>1

I458/I490<1

The Raman spectroscopy data is in a good agreement with the IR results confirming the inclusion of the [Cu(EDTA)]2- -complex in the zeolite framework.

35

20 40 60 80 100 120 140 20 40 60 80 100 120 140

20 40 60 80 100 120 140 0 100 200 300 400 500

24.46

24.48

24.50

24.52

24.54

24.56

24.58

24.60

24.62

Inte

nsity

2 / (°)

1000 a.u. 200C 500C

Inte

nsity

2 / (°)

1000 a.u.

after cooling to 27C

Inte

nsity

2 / (°)

1000 a.u.

X-ray data set

Ce

ll P

ara

mete

r a / Å

Temperature / °C

Neutrons data set

I. Yordanov, I. Karatchevtseva, H. Chevreau, M. Avdeev, R. Holmes, G. Thorogood, T. Hanley, One-step approach for synthesis of nanosized Cu-doped zeolite A crystals using the Cu-EDTA-complex. Micropor. Mesopor. Mat. 2014, 199, pp 18–28

Non-ambient Neutron Powder Diffraction study

LeBail analysis on neutron data sets recorded in Debye-Scherrer Geometry

Both the in situ XRD and NPD techniques show good agreement demonstrating the expansion of the zeolite cell during thermal treatment followed by subsequent contraction with the decomposition of the organic template.

ECHIDNA High-Resolution Powder

Diffractometer

36

Conclusions

Nanosized zeolite crystals (with BEA type framework 10 nm & LTA framework < 300 nm) have been synthesized by hydrothermal treatment using conventional heating. Formation of metal clusters (Pt & Cu) can be achieved by different reducing approaches : i) γ-radiation, ii) plasma treatment, iii) thermal treatment. The selective detection of CO on Pt- and Cu- containing porous films is demonstrated. Cu doped nanocrystals of zeolite A have been prepared by one step approach of incorporation of Cu-EDTA complex into LTA framework during the zeolite synthesis The metal containing nanomaterials assembled in thin films are of great importance for gas chemical sensing application mainly for selective detection of CO, CO2 and hydrocarbons.

37

Dr Svetlana Mintova – thesis supervisor Dr Till Metzger – beam scientist ID01 at ESRF Dr Gèrald Chaplais – MOF synthesis Dr Vincent de WAELE -– γ-irradaition

Dr Mickaël Rivallan – FTIR spectroscopy Dr Sébastien Thomas – mathematical modeling

Dr Inna Karatchevtseva – Raman spectroscopy Dr Hubert Chevreau – LeBail on X-ray data sets Dr Maxim Avdeev - beam scientist ECHIDNA beamline at ANSTO

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