inorganic nanostructured materials
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Inorganic Nanostructured Materials. Gerasimos Armatas. Research activities. Research activities focused on design and synthesis of nanostructured mesoporous materials and their applications , including: - PowerPoint PPT PresentationTRANSCRIPT
Inorganic Nanostructured Materials
Gerasimos Armatas
Research activitiesResearch activities focused on design and synthesis of nanostructured mesoporous materials and their applications, including:•Nanoporous metal oxides using ‘soft’ or ‘hard’ templated (nanocasting) self-assembly approaches•Periodically ordered mesoporous polyoxometalate-containing frameworks•Nanostructured inorganic semiconductors• Structural and chemical modification of
nanocomposite structures• Applications in heterogeneous catalysis,
absorption, optoelectronics and gas separation
Hexagonal Mesoporous Zirconia-POM Nanocomposites
0.0 0.2 0.4 0.6 0.8 1.00
10
20
30
40
50
Nitr
ogen
ads
orbe
d (c
m3/g
ST
P)
Relative pressure (P/Po)
0 5 10 15 20 25 30 35 400.000
0.004
0.008
0.012
0.016
0.020
Por
e vo
lum
e (c
m3/g
-nm
)
Pore width (nm)
c103 m2/g
Dp=5 nm
Substrate Conversion(%)
TOF(h-1)
Selectivityepoxide:alcohol:ketone
cyclooctene 82 41.0 100:0:0
cyclohexene 30 7.5 47:43:10methyl-cyclohexene 26 6.5 81:8:11
Styrene 30 7.5 5:0:95methyl-styrene 28 7.0 39:61:0
Epoxidation of alkenes with H2O2 catalyzed by 37wt% PMo12/ZrO2
Other catalytic systems include mesoporous ZrO2/[SiW12O40]4-, ZrO2/[PW12O40]3-, Al2O3/[PW12O40]3-, TiO2/[W10O32]4- nanocomposites.
G.S Armatas et el., J. Mater. Chem. 2010, 20, 8631;G.S.Armatas et el., J. Mater. Chem. 2011, 21, 2997
SBA-15Cr(NO3)3
H3PMo12O40
SBA-15Cr2O3/HPMo
Cr2O3/HPMo
400oC HFb
Mesoporous Cr2O3-Phosphomolybdic acid Solid Solution Frameworks
1000 800 600 400 200 0
Photo
ele
ctron inte
nsity (a.u
.)
Binding energy (eV)
Mo 3d
O 1s
Cr 2p
Mo 3p
Cr 3pP 2p
240 236 232 228 224
Photo
ele
ctr
on inte
nsity (
a.u
.)
Binding energy (eV)
Mo 3d
592 584 576 568
Photo
ele
ctr
on inte
nsity (
a.u
.)
Binding energy (eV)
Cr 2p
OO H
63wt% HPMo/Cr2O3
H2O2, 50 oC
Catalytic oxidation of 1-phenylethanol*
*Conv. 87%, TOF=103 h-1, 5 min, CH3CN
Other materials are mesoporous Co3O4/[PW12O40]3-, CeO2/MoO3, CeO2/Bi2O3.
Armatas et el., Chem. Mater. 2010, 22, 5739.
c. XPS
Mesoporous Germanium Semiconducting Frameworks (collaboration with Northwestern University, USA)
bulk nano
WT~1.3 nmWT~1.5 nmWT~2 nm
Decreasing pore wall thickness, increasing energy band-gap
Eg=1.86 eV Eg=1.92 eV Eg=1.97 eV
CB
VB
Band gap Evolution with Wall Thickness in a Nanostructured Semiconductor
G.S. Armatas, M.G. Kanatzidis, Nano Lett. 2010, 10, 3330
Collaborators• Prof. M. Kanatzidis (NU)• Prof. M. Louloudi (UoI)• Prof. P. Pomonis (UoI)• Prof. K. Triantafyllidis (AUTH)• Prof. I. Lykakis (AUTH)• Prof. M. Stratakis (UoC)• Dr. P. Chupas (ANL)
Funding