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2
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
4
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
6
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.
7
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
8
Approaches for preparation of Me doped …
Reducing agents
chemical reduction / γ-irradiation
Impregnation of zeolite frameworks
Adsorption and decomposition of zerovalent metal compounds
9
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
11
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]
12
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,
13
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,
14
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,
17 17
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
18
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,
19
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
21
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.
22
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)
23
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
26
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
27
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
28
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
29
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