Extract from a common kitchen spice could be key to greener, more
efficient fuel cells
While more testing is needed, the discovery brings replacing hydrogen as
a fuel cell feedstock one step closer.

Date:
April 18, 2022
Source:
Clemson University
Summary:
Researchers have discovered a novel way to combine curcumin --
the substance in turmeric -- and gold nanoparticles to create
an electrode that requires 100 times less energy to efficiently
convert ethanol into electricity.



FULL STORY ========================================================================== Turmeric, a spice found in most kitchens, has an extract that could lead
to safer, more efficient fuel cells.


========================================================================== Researchers at the Clemson Nanomaterials Institute (CNI) and their collaborators from the Sri Sathya Sai Institute of Higher Learning
(SSSIHL) in India discovered a novel way to combine curcumin -- the
substance in turmeric - - and gold nanoparticles to create an electrode
that requires 100 times less energy to efficiently convert ethanol
into electricity.

While the research team must do more testing, the discovery brings
replacing hydrogen as a fuel cell feedstock one step closer.

"Of all the catalysts for alcohol oxidation in alkaline medium, the one
we prepared is the best so far," said Apparao Rao, CNI's founding director
and the R. A. Bowen Professor of Physics in the College of Science's.

Fuel cells generate electricity through a chemical reaction instead
of combustion. They are used to power vehicles, buildings, portable
electronic devices and backup power systems.

Hydrogen fuel cells are highly efficient and do not produce greenhouse
gases.

While hydrogen is the most common chemical element in the universe,
it must be derived from substances such as natural gas and fossil fuels
because it occurs naturally on Earth only in compound form with other
elements in liquids, gases or solids. The necessary extraction adds to
hydrogen fuel cells' cost and environmental impact.



==========================================================================
In addition, hydrogen used in fuel cells is a compressed gas, creating challenges for storage and transportation. Ethanol, an alcohol made from
corn or other agricultural-based feeds, is safer and easier to transport
than hydrogen because it is a liquid.

"To make it a commercial product where we can fill our tanks with ethanol,
the electrodes have to be highly efficient," said Lakshman Ventrapragada,
a former student of Rao's who worked as a research assistant at the
CNI and is an alumnus of SSSIHL. "At the same time, we don't want very expensive electrodes or synthetic polymeric substrates that are not eco-friendly because that defeats the whole purpose. We wanted to look
at something green for the fuel cell generation process and making the
fuel cell itself." The researchers focused on the fuel cell's anode,
where the ethanol or other feed source is oxidized.

Fuel cells widely use platinum as a catalyst. But platinum suffers from poisoning because of reaction intermediates such as carbon monoxide, Ventrapragada said. It is also costly.

The researchers used gold as a catalyst. Instead of using conducting
polymers, metal-organic frameworks, or other complex materials to deposit
the gold on the surface of the electrode, the researchers used curcumin
because of its structural uniqueness. Curcumin is used to decorate the
gold nanoparticles to stabilize them, forming a porous network around
the nanoparticles. Researchers deposited the curcumin gold nanoparticle
on the surface of the electrode at a 100 times lower electric current
than in previous studies.



========================================================================== Without the curcumin coating, the gold nanoparticles agglomerate,
cutting down on the surface area exposed to the chemical reaction, Ventrapragada said.

"Without this curcumin coating, the performance is poor," Rao said. "We
need this coating to stabilize and create a porous environment around
the nanoparticles, and then they do a super job with alcohol oxidation.

"There's a big push in the industry for alcohol oxidation. This discovery
is an excellent enabler for that. The next step is to scale the process
up and work with an industrial collaborator who can actually make the
fuel cells and build stacks of fuel cells for the real application,"
he continued.

But the research could have broader implications than improved fuel
cells. The electrode's unique properties could lend itself to future applications in sensors, supercapacitors and more, Ventrapragada said.

In collaboration with the SSSIHL research team, Rao's team is testing the electrode as a sensor that could help identify changes in the level of dopamine. Dopamine has been implicated in disorders such as Parkinson's
disease and attention deficit hyperactivity disorder. When members of
the research team tested urine samples obtained from healthy volunteers,
they could measure dopamine to the approved clinical range with this
electrode using a cost- effective method compared to standard ones used
today, Rao said.

"In the beginning stages of the project, we did not imagine other
applications that gold-coated curcumin could support. However, before the
end of the alcohol oxidation experiments, we were fairly confident that
other applications are possible," Ventrapragada said. "Although we don't
have a complete understanding of what's happening at the atomic level,
we know for sure that curcumin is stabilizing the gold nanoparticles in
a way that it can lend itself to other applications."

========================================================================== Story Source: Materials provided by Clemson_University. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Sai Prasad Nayak, Lakshman K. Ventrapragada, Sai Sathish Ramamurthy,
J.K.

Kiran Kumar, Apparao M. Rao. Green synthesis of a novel porous gold-
curcumin nanocomposite for super-efficient alcohol oxidation. Nano
Energy, 2022; 94: 106966 DOI: 10.1016/j.nanoen.2022.106966 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/04/220418104909.htm

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