Chemical Engineering March 2018 - 9

A promising catalyst for
low-temperature ammonia synthesis
R
T
esearchers led by professor
Hideo Honoso at Tokyo Institute
of Technology (Yokohama City,
Japan; www.titech.ac.jp) have
discovered a new catalyst that enhances
the efficacy of NH3 synthesis by two orders
of magnitude over that of a conventional
Ru catalyst at temperatures below
300°C. Furthermore, the developed catalysts
are said to be superior to the wüstitebased
iron catalyst, which is known as a
highly active industrial catalyst at low temperatures
and pressures.
The catalyst is composed of self-organized
ruthenium-barium core-shell
nanoparticles on a mesoporous calcium
amide matrix, Ru/Ba-Ca(NH2)2. To make
the catalyst, nanometer-sized Ru-Ba
core-shell structures are self-organized
onto a Ba-Ca(NH2)2 support with 3.3-nm
dia. during H2 pretreatment at 500 °C.
The support material is simultaneously
converted into a mesoporous structure
with a high surface area (>100 m2/g),
which is higher than 17 m2/g of the raw
Ba-Ca(NH2)2 support materials. These
self-organized nanostructures account
for the high catalytic performance in lowtemperature
NH3 synthesis.
In laboratory trials, the Ru/Ba-Ca(NH2)2
catalyst performed NH3 synthesis with
turnover velocity of 7.5 mmol/g.h at 250°C
and 9 atm, well above that achieved by
industrial iron-based catalysts (2.2 mmol/
g.h) and conventional Ru-based (Cs-Ru/
MgO) catalyst (0.072 mmol/g.h).
'One-pot' synthesis of conjugated polyenes
he research group of professor
Masafumi Hirando at Tokyo University
of Agriculture and Technology
(TUAT; Koganei City, Japan; www.
tuat.ac.jp) has performed the world's first
one-pot synthesis of conjugated polyenes,
which normally require at least seven steps
by conventional methods. This shortens
the synthesis time from around a week to
as little as 30 minutes. Waste generation
is virtually eliminated due to the hydrogen
transfer reaction, which enables regio- and
stereo-selective reactions for making precursors
for electronics chemicals, vitamins
and pharmaceuticals.
At room temperature, the new synthesis
approach directly produces conjugated
tetraenes with 85% yield by reacting
1,3-butadiene over a Ru(0) catalyst
containing two internal alkyne ligands. The
stoichiometric reaction of [Ru(4-cisoid1,3-butadiene)(4-1,5-COD)(NCMe)]
with
two equivalents of 3-hexyne produces a
tetraene complex of Ru(0), [Ru{3-6-4(3E,5E,7E,9E)-4,9-diethyldodeca-3,5,7,9tetraene}(4-1,5-COD)(NCMe)],
in 98%
yield. When exposed to 1,3-butadiene,
the conjugated tetraene ligand is released
with 92% yield. The study is described in a
recent issue of Organometallics.
An explosive way to make
porous organic networks
A
team from Ulsan National Institute
of Science and Technology (Ulsan,
South Korea; www.unist.ac.kr),
led by professor Jong-Beom
Baek has introduced a synthetic methodology
for fabricating a three-dimensional
porous organic network with a high specific
surface area via a solid-state explosion
of organic single crystals containing
primer molecules. The method involves
the Bergman reaction (cyclo-aromatization)
of 2,3,6,7, 14, 15-hexaethynyl-9,10dihydro-9,10-{1,2}benzenoanthracene
(HEA),
which is a self-polymerizable trifunctional
(M3) building block with three
enedyne groups (containing a double bond
and two triple bonds). X-ray diffraction
suggested that two acetone molecules
and one water molecule are regularly positioned
in the HEA crystal lattice. The acetone
and water molecules play a role as
primer to trigger explosion. Solid-organic
materials can easily melt when heat is applied.
However, the newly-developed HEA
single crystals trigger explosive Bergman
reactions and quickly changes to 3-D porous
materials when heat is applied, without
the presence of solvents and catalysts.
The polyHEA obtained is a porous material
with specific surface area of 1,176 m2/g displaying
unusual sorption capacity for CO2.
The team's method could pave the way for
designing and synthesizing molecules suitable
for the solid-state formation of other
porous organic networks for applications
beyond those of liquid-phase processes. n
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
MARCH 2018
SUEZ produces new raw materials
and alternative energy from
waste, but also from bottom ash.
Now, using the internally developed
Valomet process, the company
will also recover fine, nonferrous
metal particles (up to 20
mm in size) from bottom ash. In
November 2015, a pilot project
began in Ghent in which metal concentrates
from bottom ash were
processed and separated. Over
a one-year trial period, SUEZ extracted
around 1,300 metric tons
of fine metal particles, which were
then returned to the production
process, through foundries and
metal refineries. This pilot project
recovered aluminum and denser
non-ferrous metals, such as copper,
lead and zinc.
The new facility, which is expected
to be operational by the end of this
year, represents a tenfold scaleup,
and will have the capacity to process
up to 12,000 m.t./yr by 2019. The
materials processed will come from
European countries, including Belgium,
France, the U.K. and Poland.
Researchers
HANDY ANALYSIS
the
at
Fraunhofer
Institute for Integrated Circuits
(IIS; Erlangen, Germany; www.iis.
fraunhofer.de), in cooperation with
CapSenze Biosystems AB (Lund,
Sweden; www.capsenzw.se) have
developed a mobile measuring
device that can quickly and reliably
detect the presence of biochemical
substances in liquids, such as drinking
water or juices. The matchboxsized
device, which integrates a
biosensor developed by CapSenze
and an optimized evaluation circuit
from IIS, is able to perform measurements
in a couple of minutes,
compared to the time-consuming
process of sending samples to
laboratories for analysis.
Supplying measurement data in
the pico- to femtomole (10-12 to
10-15 mol/L) range, the six different
sensors of the biosensor system
allow simultaneous detection
of six different substances. Different
sensor coatings, depending
on the substance to be detected,
are used to determine the presence
of unwanted substances in
foodstuffs and animal feed. The
biosensor system is a highly sensitive
device that can identify, with
the corresponding sensor coating,
the presence of biochemical
substances, such as hormones,
pesticides and mycotoxins in extremely
low concentrations. ❑
9

http://www.titech.ac.jp http://tuat.ac.jp http://www.iis http://www.fraunhofer.de http://www.capsenzw.se http://www.unist.ac.kr http://WWW.CHEMENGONLINE.COM

Chemical Engineering March 2018

Table of Contents for the Digital Edition of Chemical Engineering March 2018