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Research Topic 5
Computations Using Density Functional Theory
MnO4AlO
(O2)MnO4AlO
Model compounds
HF / 6-31G*
HF - 6-311G
Projects
– Intermediates in oxidation of organics
– Hydrogen interactions in silica
– Adsorbed species on phosphide clusters
Membrane Diffusion Energy
Calculations
Model: Becke3lyp (DFT)
x
Basis set: 6-311G(2d,p)
Diffusion Energy
z
y
Normal to
the xy plane
Saddle Point
Activation Energy vs. Distance to O atoms
Activation Energy / kJ mol
-1
1000
4-membered
5-membered
100
6-membered
10
Glasses
Silica layer
7-membered
8membere
Helium
d
Hydrogen
1
0.1
0.20
0.24
0.28
0.32
0.36
0.40
Center to Oxygen Distance / nm
P. Hacarlioglu, D. Lee, G.V. Gibbs and S.T. Oyama,
J. Membr. Sci. 2008, 313, 278-283 .
Multicomponent Membranes
4.1 A
3.9 A
3.5 A
silica
germania
alumin
a
4.3 A
boria
4.0 A
titania
5.2 A
yttria
5.3 A
zirconi
Characterization of Catalysts
Laser Raman
Spectroscopy (LRS)
Extended X-ray Absorption
Fine Structure (EXAFS)
2.0
Mo
1550
O
2000
2
819
804
SiO
O
Mo
Intensity / A.U.
984
O
Mo
2
1500
1000
Raman Shift / cm -1
500
Vibrational frequencies
X-ray Absorption Near
Edge Spectroscopy (XANES)
Intensity / A.U.
2.0
1.5
1.0
0.5
0.0
-0.5
-200
0
200
Energy / eV
400
Bond distances
Ab Initio Molecular Orbital
Calculations (Gaussian)
1.5
1.0
0.5
0.0
-0.5
-50
0
50
Energy / eV
100
Symmetry
150
Theoretical values
Molecular Dynamics Simulations
• Structure of membranes
• Inorganic-organic hybrids
• Permeation studies
10% Removed
30% Removed
Phenyl substitution