Chemical Engineering December 2022 - 5

Chementator
Iridium-free electrolysis demonstrated for stable
hydrogen production
T
he necessity
for
precious metals,
such as iridium, in water-splitting
catalysts is a major challenge in the
feasibility of large-scale production of
hydrogen using electrolysis. Now, a team of
researchers from Rice University (Houston;
www.rice.edu) has developed a mechanism
for replacing iridium with ruthenium, which
is significantly more abundant and less expensive,
into an electrolysis anode catalyst.
To make the catalyst, a three-step process
was developed to incorporate nickel into a
RuO2 lattice. " First, a wet impregnation of
metal precursors was adopted on the carbon
black support, which was followed by
H2/Ar annealing reduction to obtain Ru3Ni
nanoparticles supported on carbon black
(Ru3Ni/C). Secondly, the obtained Ru3Ni/C
complex was annealed in air to convert the
nanoparticles to Ru3NiOx and to remove
the carbon supports. Finally, the Ru3NiOx
underwent an acid-leaching process to remove
unstable Ni species and get the final
catalyst, Ni-RuO2, " explains Haotian Wang,
assistant professor of chemical and biomolecular
engineering at Rice. This method resulted
in a stable anode catalyst, which the
team says has been employed in an electrolysis
cell to produce hydrogen for thousands
of hours under ambient conditions.
N
ext April, a six-year, €4-million
project will begin that aims to develop
an electrochemical process
to recover halogens (chlorine, bromine
and fluorine) from waste products.
Funded as part of the CZS Breakthrough
program of the Carl Zeiss Foundation (CZS;
Heidenheim an der Brenz, Germany; www.
carl-zeiss-stiftung.de), the Halocycles project
has three major objectives: increasing
the recovery of fossil raw materials, avoiding
CO2 emissions and stabilizing the energy-supply
network. It will be carried out
by partners Johannes Gutenberg University
Mainz (JGU; www.uni-mainz.de) and the
Technical University of Kaiserslautern (both
Germany; www.uni-kl.de). Additional participants
in the project are the Max-Planck
Institute for Polymer Research (Mainz) and
the Leibniz-Institute für Verbundwerkstoffe
GmbH (IVW; Kaiserslautern).
There are many common products made
from halogen compounds, such as polyvinylchloride
(PVC), polytetrafluoroethylene
(PTFE or Teflon) and flame retardants. Their
unique properties make them irreplacable
Edited by:
Gerald Ondrey
Li EXTRACTION
A new technology is
going to be introduced at
the Schlumberger NeoLith
Energy direct lithiumextraction
(DLE) project
in
Rice
University
According to Wang, the team believes their
catalyst could be integrated into different
types of polymer electrolyte membrane
(PEM) electrolyzer.
Thus far, the team has loaded the catalyst
on a 1-cm2 platinized titanium fiber-felt
electrode at a rate of around 3.1 mg/cm2,
and for each batch of synthesis, around 100
mg of Ni-RuO2 can be produced. " We plan
to scale up the synthesis of our Ni-RuO2
catalysts by using larger reaction vessels
and tube furnaces, " adds Wang. The team
is also examining ways to improve current
density in the cell.
Recycling halogens electrochemically
in many applications, and these properties
also make them difficult to recycle. Today,
the only way to recover the halogens, which
are becoming more expensive, is to incinerate
the halocarbons, and then recover the
halogens via fluegas-scrubbing techniques.
However, burning these compounds not
only requires additional fuels for achieving
the required temperatures to breakdown the
compounds, but also destroys the carbon
backbone, which is then released as CO2.
" In our new Halocycles project, we are
approaching this issue from a completely
different direction, " says professor Siegfried
Waldvogel of JGU's Department of Chemistry,
who is the project's spokesperson and
an authority on electrosynthesis (see " Electrochemistry
Spreads its Wings, " Chem.
Eng., September 2021, pp. 12-16). " Our
idea is to use an electrochemical technique
to recover the halogens without burning the
carbon structures. Thus, we also avoid the
formation of dioxins. "
The partners will also consider utilizing
and exploiting the results of the research in a
spin-off, which may be established later on.
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
DECEMBER 2022
Clayton Valley, Nev.
Developed by Gradiant
Ventures (Boston, Mass.;
www.gradiant.com), the
technology enables high
levels of lithium concentration
(while simultaneously
generating fresh
water) using a fraction
of the time required by
conventional thermal
concentration methods,
explains Gradiant's chief
operating officer, Prakash
Govindan. " This is the first
industrial-scale deployment
of the technology
for battery-grade lithium
production, " he adds,
noting that the technology
has previously been
demonstrated in production
processes for gold,
nickel and graphite.
Based on research work
from the Massachusetts
Institute of Technology
(MIT; Cambridge, Mass.;
www.mit.edu), Gradiant's
technology is also set for
deployment for ultrapure
water treatment at a
semiconductor manufacturer
in Singapore starting
up in early 2023.
VEGETABLE OIL
Scientists from Nanyang
Technological University,
Singapore (NTU Singapore;
www.ntu.edu.sg)
have genetically modified
a plant protein that is
responsible for oil accumulation
in plant seeds
and edible nuts. Demonstrating
their patentpending
method, the
model plant Arabidopsis
accumulated 15 to 18%
more oil in its seeds when
it was grown with the
modified protein under
laboratory conditions.
The secret to helping
plants store more oil in
(Continues on p. 6)
5
http://www.rice.edu http://www.gradiant.com http://www.mit.edu http://www.carl-zeiss-stiftung.de http://www.carl-zeiss-stiftung.de http://www.ntu.edu.sg http://www.uni-mainz.de http://www.uni-kl.de http://WWW.CHEMENGONLINE.COM
Chemical Engineering December 2022

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