1. 200 300 400 500 600 700 800
Absorbance(a.u.)
Wavelength,  (nm)
Na-LTA
Cu-EDTA
Cu-EDTA-LTA
200 400 600 800 1000 1200
Intensity(a.u.)
Raman shift (cm
-1
)
Cu-EDTA-TMA-LTA
Na-TMA-LTA
Na-LTA
10 20 30 40 50
Na-LTA
Cu-EDTA-LTA
LTA - simulated XRD pattern
Intensity(a.u.)
2 (deg), Cu K
PREAPARATION OF NANO - CRYSTALS OF ZEOLITE - A,
USING COPPER - EDTA AS A CO -TEMPLATE
I. Yordanov1, R. Knott1, I. Karatchetseva1, T. Hanley1
1 Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
Study the mechanisms of crystallization of zeolite
Linde A, using Cu-EDTA complex as a co - template
agent.
Aim
Nanosized crystals of zeolite A (LTA - framework), with incorporated metal species, have been synthesised via “in-situ”
crystallization, using an ethylenediaminetetraacetic acid (EDTA) copper complex as co-template agent. The process has been
studied using Dynamic Light Scattering (DLS) and Small Angle X-Ray Scattering (SAXS).
Experimental part
1. Mintova, S.; Olson, N. H.; Valtchev, V.; Bein, T. Science 1999, 283, 958.
2. Wagreich, H.; Harrow, B. Analytical Chemistry 1953, 25, 1925
3. Fan, W.; Ogura, M.; Sankar, G.; Okubo, T.; Chem. Mater. 2007, 19, 1906
4. Grizzetti, R.; Artioli, G.; Gemmi, M.; Carsughi, F.; Riello, P. Stud. Surf.Sci.
Catal. 2004, 154, 355
LTA frameworkβ - cage
Cu2+
EDTA+TMA+
Cu-EDTA – confined in sodalite cage of zeolite A
100 nm
280cm-1
337cm-1
410cm-1
700cm-1
C-H – 755 – 770 cm-1
Raman data
The presence of organic templated molecules
confined in porous matrix lead to decreasing of
vibration mode of the framework
UV-vis spectraXRD patterns
The XRD pattern of Cu-EDTA-LTA contains only the
typical for LTA zeolite framework Bragg reflections
300 nm 500 nm
Na-LTACu-EDTA-LTA
References
252 nm
300 nm
Due to the confinement
effect of the zeolite matrix λ
of Cu-EDTA-complex has
shifted to lower wavelengths
Nanosized crystals of zeolite A doped with Cu can be prepared via
“in-situ’ incorporation of the Cu-ions in the form of a complex with
templated agent (EDTA). The in-situ incorporation permits the
preparation of zeolites with homogenous distribution of guest
species in the porous matrix.
Conclusions
LTA framework
Space Group: Pm-3m
a = b = c = 11.919 Å
α = β = γ = 90°
V = 1693.24 Å3
Channel system 3D
α – cagePore opening
O
O
4.2 Å
Na+
O
β – cage
11.4 Å
O
Na+
Linde AIn-situ DLS study
PSD as scattering intensity
per number particle size classes
dH~35nm dH~400nm
β – cage
11.4 Å
Cu- EDTA
10.5 Å
TMA+
Dissociation
Monomeric/dimeric (4R-
TMA+) species
Aggregation
Primary units
Mass transport,
aggregation, compaction
Secondary population
particles
Crystals growth
Zeolite nano-crystals,
long-range order
α – cage
Cu-EDTA-LTA molar composition of the initial precursor suspension:
0.25Cu-EDTA:1.8Al2O3:11.3SiO2:13.5(TMA)2O:650H2O:100NH3
6
4.75
3.5
2.25
1
1 10 100 1000 10000
Hydrodynamic diameter dH
, (nm)
Time,(hours)
ScatteringIntensity(a.u.)
SAXS investigation
0.01 0.1
Experimental point; Model curve
Intensity(a.u.)
Q (A
-1
)
0.01 0.1
Intensity(a.u.)
Q (A
-1
)
Experimental point; Model curve
Species with a medium-
range order (and size
about 19 nm; <d> = 18.59
nm) have been found in an
aged (at 308 K for 5 days)
initial suspension
In the as-synthesised
suspension was found to
have particles with a long-
range order and size ~ 22
nm (<d2> = 22.4 nm) –
zeolite crystals (confirmed
by XRD data)
SAXS data is consistent with DLS studies. The SAXS studies give more information about the smaller species present in the earlier stages of nucleation
0.01 0.1
Q (A
-1
)
Intensity(a.u.)
Time
<d> = 18.59 nm
R = 9.3 nm
Rg = 7.2 nm
<d> = 22.4 nm
Rg = 8.68 nm