Researchers at the University of Illinois Chicago have developed a material that could pave the way for future fuel cell-powered vehicles.
Fuel cell technology relies on catalyst-driven chemical reactions to create energy. Lithium batteries can typically achieve a range of 100-300 miles on a single charge, but are also vulnerable to the high cost of cathode materials and fabrication, taking several hours to charge.
Alternatively, fuel cell systems take advantage of abundant elements such as oxygen and hydrogen and can travel more than 400 miles on a single charge, which can be done in less than five minutes. The catalysts used to drive their reactions are made of materials that are either too expensive (eg, platinum) or that degrade too quickly to be practical.
US scientists have now reportedly developed an additive material that allows for a more durable, cheaper iron-nitrogen-carbon fuel cell catalyst.
When added to the chemical reactions, researchers said the additive material protects fuel cell systems from two of the most corrosive byproducts: unstable particles such as atoms, molecules or free radicals and hydrogen peroxide.
Reported in Nature EnergyThe team’s work involved using advanced imaging techniques to examine reactions with the material, an additive made up of tanatlum titanium oxide nanoparticles that scavenge and deactivate the free radicals. High-resolution imaging of the atomic structures allowed the scientists to define the structural parameters needed for the additive to work.
“In our lab, we are able to use electron microscopy to capture highly detailed atomic-resolution images of the materials under various conditions of use,” said co-corresponding author Reza Shahbazian-Yassar, professor of mechanical and industrial engineering at UIC College. or Engineering.
“Through our structural research, we learned what happened in the atomic structure of additives and were able to identify the size and dimensions of the scavenger nanoparticles, the ratio of tantalum and titanium oxide. This led to an understanding of the proper condition of the solid solution alloy required by the additive to protect the fuel cell from corrosion and degradation.”
Experiments showed that a solid solution of tantalum and titanium oxide is needed and that the nanoparticles should be around five nanometers. They also revealed that a 6-4 ratio of tantalum to titanium oxide is required. Shahbazian-Yassar said the ratio was key to the radical scavenging properties of the nanoparticle material, and the solid solution helped maintain the structure of the environment.
When the scavenger nanoparticle material was added to the reactions of fuel cell systems, the hydrogen peroxide yield was suppressed to less than two percent — a 51 percent reduction — and the current density decay of fuel cells was reduced from 33 percent to just three percent, researchers confirmed.