Research Topic 5

Research Topic 5

Computations Using Density Functional Theory

MnO4AlO

HF / 6-31G*

(O2)MnO4AlO

HF - 6-311G

Projects– Intermediates in oxidation of organics– Hydrogen interactions in silica– Adsorbed species on phosphide clusters

Model compounds

Membrane Diffusion Energy Calculations

Model: Becke3lyp (DFT) Basis set: 6-311G(2d,p)

x

y

z

Normal tothe xy plane

Saddle Point

Diffusion Energy

Activation Energy vs. Distance to O atoms

0.20 0.24 0.28 0.32 0.36 0.400.1

1

10

100

1000

A

ctiv

atio

n E

nerg

y / k

J m

ol-1

Center to Oxygen Distance / nm

Hydrogen

Helium

8-membered

4-membered

5-membered

6-membered

7-memberedGlassesSilica layer

P. Hacarlioglu, D. Lee, G.V. Gibbs and S.T. Oyama, J. Membr. Sci. 2008, 313, 278-283 .

Multicomponent Membranes

boria

4.3 A

alumina

3.5 A

silica

4.1 A

4.0 A

titania

3.9 A

germania

yttria

5.3 A5.2 A

zirconia

Characterization of Catalysts

X-ray Absorption NearEdge Spectroscopy (XANES)

-50 0 50 100 150-0.5

0.0

0.5

1.0

1.5

2.0

Inte

nsi

ty /

A.U

.

Energy / eV

Extended X-ray AbsorptionFine Structure (EXAFS)

-200 0 200 400-0.5

0.0

0.5

1.0

1.5

2.0

Inte

nsi

ty /

A.U

.

Energy / eV

Laser Raman Spectroscopy (LRS)

O

SiO

804

2

1550

O2

819Mo

O

MoMo

984

2000 1500 1000 500Raman Shift / cm-1

Ab Initio Molecular Orbital Calculations (Gaussian)

Theoretical valuesSymmetry

Vibrational frequencies Bond distances

Molecular Dynamics Simulations

• Structure of membranes

• Inorganic-organic hybrids

10% Removed 30% Removed Phenyl substitution

• Permeation studies