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A D V A N C E D M A T E R I A L S & P R O C E S S E S | J A N U A R Y 2 0 1 7
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NEWMOF OFFERSDIRECT CO2
CAPTURE
Researchers at the King Abdullah
University of Science and Technology
(KAUST), Saudi Arabia, developed a
new metal organic framework (MOF)
that can trap carbon dioxide at concen-
trations as low as 400 ppm—potentially
low enough to capture the gas as it is
generated. The gas adsorbtion and stor-
age capabilities of a specific MOF are
determined by the chemical compo-
sition and geometry of its major com-
ponents—metal ions or clusters held
in place by organic molecules known
as linkers. Square-shaped grid layers
composed of Ni(II) metal centers and
pyrazine linkers are bridged by pillars
composed of niobium, oxygen, and flu-
orine atoms.
“The ability to control the distance
between the fluorine atoms allows us to
create the ideal square-shaped pockets
for trapping carbon dioxide molecules
effectively and efficiently,” explains
Professor Mohamed Eddaoudi. The
MOF could be adapted to static indus-
trial processes, such as those used at
cement factories, but could also be
used on board vehicles to capture CO2
at the point of emission—a significantly
more effective and efficient method
than removing it after it has mixed with
the atmosphere. .
INTESTINE-INSPIRED MATERIAL
BEATS BATTERY BREAKDOWN
Researchers at the University of
Cambridge, UK, developed a prototype
of a next-generation lithium-sulfur bat-
tery that couldhave five times the energy
density of today’s lithium-ion batteries.
The design incorporates a chemically
functional layer inspired by the lining
of the human gut that drastically slows
the degradation of active material, over-
coming a key obstacle to the commercial
development of this type of battery.
When a Li-S battery discharges, the
lithium and sulfur interact to form chain-
likepolysulfides.Over several cycles, seg-
ments of these polysulfides can break off
and enter the electrolyte, decreasing the
available activematerial. The Cambridge
EMERGING TECHNOLOGY
team’s functional layer lies on top of the
cathode to trap the detached active
material and fix it to a conductive frame-
work so it can be reused. Modeled after
villi—the fingerlike protrusions that line
the small intestine, increasing its surface
area and absorbing nutrients—themate-
rial consists of tiny, one-dimensional
zinc oxide nanowires grown on a scaf-
fold. It uses a lightweight carbon fiber
mat for support, which reduces overall
battery weight and, due to its flexibility,
allows the layer to mimic how the small
intestine works even further. Because of
the layer’s strong chemical bond with
the polysulfides, the active material
can be used for much longer, greatly
increasing the battery’s lifespan. “This
is the first time a chemically functional
layer with a well-organized nano-archi-
tecture has been proposed to trap and
reuse the dissolved active materials
during battery charging and discharg-
ing,” explains Ph.D. student Teng Zhao.
.
Solid MOF for carbon dioxide capture.
Courtesy of King Abdullah University.
BRIEF
Thermo-Calc Software AB, Sweden, and QuesTek International LLC, Evanston, Ill., will establish a joint company, QuesTek
Europe AB, Sweden, to offer integrated computational materials engineering modeling services and novel materials design and
development in the European market. The new endeavor will combine the Materials by Design methodology developed in the U.S.
by QuesTek with the software and databases in the Thermo-Calc platform.
Computer visualization of villi-like battery material. Courtesy of Teng Zhao.