4th EucheMs chemistry congress

thursday, 30-Aug 2012
s666
chem. Listy 106, s587–s1425 (2012)
Environment and Green Chemistry
Green Chemistry – Vi
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redox-ACtive vAnAdiuM PoLyoxoMetALAteS
for enerGy ProduCtion And StorAGe
P. MoLinA SAnChez 1 , M. SyMeS 1 , C. Lydon 1 ,
C. BuSChe 1 , h. MirAS 1 , d. L. LonG 1 , L. Cronin 1
1 University of Glasgow, School of Chemistry, Glasgow, United
Kingdom
Email: L.Cronin@chem.gla.ac.uk
Polyoxometalates (POMs) are anionic molecular oxides of
early transition metals, such as Mo, W, V and Nb, which possess
an unmatched ability to incorporate almost every single element
from the periodic table in their structure. This rich elemental
composition together with a vast diversity in size and topology
help to explain their extraordinary flexibility in a range of physical
properties. For instance, POMs are generally soluble in water yet
they can be made soluble in a range of organic solvents and they
tend to exhibit a wealth of redox processes whilst keeping their
structure intact. These, in particular, make POMs ideal candidates
for energy storage and catalytic applications related to green
energy production.
In this light, we present [P V W O ] 4 6 30 120 10- , a Wells–Dawson
polyoxometalate sandwich compound with a double cubane core
consisting of six vanadium atoms1 . The formation of the cluster
is followed by mass spectrometry and the reduction of the double
cubane is studied by a novel technique combining mass
spectrometry and spectroelectrochemistry. Catalytic properties of
[P V W O ] 4 6 30 120 10- are evaluated in connection with solar fuels
production and compared to other members of the vanadium
polyoxotungstate family. A new device concept is also presented
linking the ideas of energy production and storage in one
molecular system.
references:
1. Lydon, C., Busche, C., Miras, H.N., Delf, A., Long,
D. L.,Yellowlees, L., Cronin, L. Angew. Chem. Int. Ed.
2012, 51, 2115-2118.
Keywords: Polyoxometalates; Vanadium; Mass spectrometry;
Electrochemistry;
Green Chemistry – Vi
4 th EucheMs chemistry congress
o - 4 4 3
exPeriMentAL And theoretiCAL CoMPAriSon
of An equAtion of StAte for Pore-Confined
fLuidS
P. LóPez-ArAnGuren oLiver 1 , L. f. veGA 2 ,
C. doMinGo 1 , e. h. ChiMowitz 3
1 ICMAB (CSIC), Solid State Chemistry, Bellaterra, Spain
2 Matgas Research Center and Carburos Metalicos Air Products
Group, Matgas, Bellaterra, Spain
3 University of Rochester, Chemical Engineering, Rochester,
USA
The prediction of properties in porous materials is of
continuing interest in the fields of chemical and materials
engineering. Application areas include, among others: (a) the use
of supercritical fluids to modify porous materials, (b) physical
adsorption of trace components from gaseous effluents, (c) gas
storage using micro-porous materials, and (d) chemical
separations using inorganic membranes.
There is a need for useful thermodynamic models in this
area and here we present an equation of state (EOS) for
calculating the thermodynamic properties of both bulk and poreconfined
fluids. We illustrate for the first time the application of
this EOS to both realistic bulk and single component adsorption
systems. The model is a mean field type derived from a statistical
mechanics approach carried out in the grand canonical ensemble.
In pure fluids, the only properties required are the bulk fluid’s
critical properties. In adsorption systems, the fluid-solid matrix
interaction parameter is required.
We show comparisons between the model and the
Peng-Robinson (PR) equation of state, for methane and carbon
dioxide in the bulk fluid case. However, our EOS has an important
advantage over the original PR EOS in that it seamlessly carries
over into predictions of the pore-confined fluid thermodynamic
properties. We illustrate this point using recently published
adsorption data in a carbon dioxide-silica aerogel system.
Keywords: Supercritical fluids; Adsorption; Statistical
thermodynamics;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc