The Catalyst Review June 2020 - 5

Controlling the Zeolite Pore
Interior for Chemo-Selective
Alkyne/Olefin Separations...
In a new report, Yuchao Chai and an
international research team in advanced
materials, chemical physics, neutron
sciences and the Diamond Light Source
in the U.K., U.S., and China developed a
new strategy to control the interior pore
of faujasite (FAU) zeolites. They achieved
this by confining isolated open nickel(II)
sites in their six-membered rings. Under
ambient conditions, the Nickel (Ni)
FAU sites (known as Ni@FAU) showed
remarkable adsorption of alkynes and the
efficient separation of acetylene/ethylene,
propyne/propylene, and butyne/1-3,
butadiene mixtures with unprecedented
separation selectivity. Using in situ
neutron diffraction and inelastic neutron
scattering techniques, the team showed
how confirmed nickel(II) sites allowed
chemo-selective and reversible binding
to acetylene by forming metastable
[Ni(II)(C2H2)3] complexes. The ability to
control the chemistry of pore interiors
of easily sealable zeolites unlocked their
potential to achieve challenging industrial
separation. The work is now published in
Science. Source:, 6/9/2020.
Producing Ammonia with
Small-Scale Electrochemical
A team of MIT chemical engineers has
developed an electrochemical process
for producing ammonia that reduces
emissions and could allow decentralized
production of ammonia in remote
areas. Ammonia is typically produced
via the Haber-Bosch process, which is
responsible for around 1.8% of global CO2
emissions, according to the Royal Society.
Electrochemical production of ammonia
has been performed in other studies, but
there have been challenges that have
been difficult to overcome. The MIT team
developed a way to use a gas diffusion
electrode in a non-aqueous solution to
improve the rate of ammonia production.
They used gas diffusion electrodes made
of a stainless-steel cloth (SSC), which do
not become flooded by the electrolyte.

The SSC anode is coated in platinum, and the SSC cathode is coated in lithium, which
acts as a catalyst. The hydrogen is produced in a separate electrochemical cell from
the splitting of water and is fed into the ammonia-producing cell at the anode. The
ammonia-producing cell uses an electrolyte of ethanol dissolved in THF. The ethanol is
used to form ethoxide at the cathode and in the process the nitrogen becomes reduced
to ammonia. At the anode, protons are produced from oxidized hydrogen molecules,
and then the ethoxide is converted back into ethanol. The ammonia production rate is
a record for electrochemical production, however the energy efficiency is still only 1.4-
2.8%, so it cannot yet compete with the energy efficiency of the Haber-Bosch process,
which is around 50-80%. Source: The Chemical Engineer, 6/9/2020.
New Low-Cost and High-Performance Multinary Intermetallic
Compound as Active Electrocatalyst for Hydrogen Production...
A team comprising scientists who specialize in structure materials at City University
of Hong Kong (CityU) has developed a high-performance electrocatalyst based on an
innovative concept originally for developing alloys. The new electrocatalyst can be
produced at large scale and low cost, providing a new paradigm in a wide application of
hydrogen production by electrochemical reaction in future. The research was co-led by
Professor Lu Jian, CityU's Vice President (Research and Technology) and Chair Professor
of Mechanical Engineering, and Professor Liu Chain-tsuan, University Distinguished
Professor of the College of Engineering.
Compared to
other methods
of hydrogen
water splitting
is a relatively
friendly process Conceptual design of the multinary intermetallic electrocatalyst. This schematic
with promising diagram shows the dealloying process from a dual-phase structure to a dendritic-like
structure. Source: CityU
potential in
applications. Earlier, Professor Liu developed an innovative alloy design strategy for
manufacturing high-entropy intermetallic compounds. This strategy overcomes the
trade-off dilemma between strength and ductility in traditional metallic materials by
introducing high density of nanoparticles of multi-component intermetallic compounds
at the nano-scale. Since the high-entropy intermetallic compounds possess wellordered atomic structures and chemical synergistic functions (thanks to its multicomponents), both of which promote the electrocatalytic performance, the new alloy
design strategy also provides insight for developing novel electrocatalysts.
The new electrocatalyst mainly comprises iron, cobalt, nickel, aluminum and titanium.
It also has a well-ordered atomic structure. Through a simple and one-step chemical
method, the team produced a dendrite-like porous structure which greatly increased
the surface area for electrochemical activities and hence significantly enhancing the
electrochemical performance. With further theoretical calculations, they proved that
the synergistic effects and the well-ordered atomic structure effectively optimize the
electronic structure, and hence promote the electrochemical water splitting process.
Because of its unique constituents and structure, this HEI catalyst performs excellent
hydrogen evolution reaction in alkaline electrolyte. Source: Green Car Congress,

The Catalyst Review 										


June 2020



The Catalyst Review June 2020

Table of Contents for the Digital Edition of The Catalyst Review June 2020

The Catalyst Review June 2020 - cover
The Catalyst Review June 2020 - contents
The Catalyst Review June 2020 - 1
The Catalyst Review June 2020 - 2
The Catalyst Review June 2020 - 3
The Catalyst Review June 2020 - 4
The Catalyst Review June 2020 - 5
The Catalyst Review June 2020 - 6
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