Curcumin and gold nanoparticles have been combined to create an electrode that requires 100 times less energy to convert ethanol into electricity.
This is what researchers from the Clemson Nanomaterials Institute (CNI)South Carolina and their associates from the Sri Sathya Sai Institute of Higher Education (SSSIHL) in india.
Although the research team needs to do more tests, the discovery could eventually lead to hydrogen being replaced as a feedstock for fuel cells.
“Of all the catalysts for alcohol oxidation in alkaline medium, the one we’ve prepared to date is the best,” said Apparao Rao, founder of CNI and the RA Bowen Professor of Physics in the Clemson’s College of Science†
Hydrogen is the most abundant chemical element in the universe, but it must be derived from substances such as natural gas and fossil fuels, as it occurs naturally only in compound form on Earth. The necessary extraction adds to the cost and environmental impact of hydrogen fuel cells.
In addition, hydrogen used in fuel cells is a compressed gas, which poses a challenge for storage and transportation. According to CNI, ethanol — made from corn or other agriculture-related feeds — is safer and easier to transport than hydrogen because it’s a liquid.
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“To make it a commercial product where we can fill our tanks with ethanol, the electrodes need to be very efficient,” said Lakshman Ventrapragada, SSSIHL alumnus and research assistant at CNI. “At the same time, we don’t want very expensive electrodes or synthetic polymer substrates that are not environmentally 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 anode of the fuel cell, where the ethanol or other food source is oxidized.
Fuel cells widely use platinum as a catalyst, but the metal suffers from poisoning from reaction intermediates such as carbon monoxide, Ventrapragada said in a statement. It is also expensive.
Rather than using conductive polymers, metal-organic frameworks or other complex materials to deposit the gold on the surface of the electrode, the researchers used curcumin — a compound in turmeric — for its structural uniqueness. Curcumin is used to decorate the gold nanoparticles to stabilize them, forming a porous network around the nanoparticles. Researchers applied the curcumin gold nanoparticle to the surface of the electrode with an electric current 100 times lower than in previous studies.
Without the curcumin coating, the gold nanoparticles agglomerate, reducing the surface area exposed to the chemical reaction, Ventrapragada said.
“Without this curcumin coating, performance is poor,” Rao said. “We need this coating to stabilize and create a porous environment around the nanoparticles, and then they do a great job with alcohol oxidation.
“There is a lot of pressure in the alcohol oxidation industry. This discovery is an excellent enabler for that. The next step is to scale up the process and work with an industrial worker who can make the fuel cells and build stacks of fuel cells for the real application,” he continued.
The electrode’s unique properties could also lend itself to future applications in sensors, supercapacitors and more, Ventrapragada said.
The team’s findings were published in Nano-energy†
