United States – Engineers at the University of Illinois Chicago are part of a collaborative team that developed a material that could give fuel cell systems a competitive advantage over the battery systems that currently power the majority of electric vehicles.
Instead of relying on lithium batteries, fuel cells generate energy through catalyst-driven chemical reactions. However, due to the high cost of cathode materials and production, lithium batteries can only travel 100-300 miles on a single charge and must be recharged for several hours. Fuel cell systems can achieve more than 400 miles on a single charge by utilizing abundant elements such as oxygen and hydrogen, which can be accomplished in five minutes. Platinum is either too expensive or degrades too quickly to be useful as a catalyst for their reactions, so they can’t use it.
At least for the time being. By developing a new additive material, scientists can improve the durability of a low-cost iron-nitrogen-carbon fuel cell catalyst. The additive material protects fuel cell systems from two of the most corrosive byproducts of chemical reactions: free radicals, which are unstable particles like atoms, molecules, or ions, and hydrogen peroxide. This additive material is used in chemical reactions.
Reza Shahbazian-Yassar, a mechanical and industrial engineering professor at UIC, and his colleagues studied reactions with the material, which is an additive made of tantalum-titanium oxide nanoparticles. The scientists used high-resolution imaging of atomic structures as a guide to make the additive work.
Experiments revealed that tantalum and titanium oxide nanoparticles with a diameter of five nanometers or less performed best. Furthermore, a tantalum to titanium oxide ratio of 6-4 was discovered to be required in the tests. According to the results of the experiments, scavenger nanoparticles reduced hydrogen peroxide yield by 51% and current density decay by a factor of three when added to the reactions of fuel cell systems.
The study was supported by the Department of Energy, the National Science Foundation, and the Maryland Nano Center.