Although fuel cells are often praised as the clean, green solution to the present’s energy crisis, we rarely hear what’s keeping them from coming into fully functional fruition. Fuel cells have shabby endurance. On a long enough timeline, the incinerating components used in today’s most advanced fuel cells decompose, slowing the chemical reaction required to convert liquid fuel into potent electricity. What’s worse is the fact that the most advanced technology available relies on micro-particles layered with chemicals required to activate the reaction, but the particles are so small that their surface area limits the amount of catalyst available from moment to moment.
WHY. SO. SERIOUS.
But recently a team of engineers from the Yale School of Engineering & Applied Science created an alternate fuel cell catalyst system that relies on nanowires developed form a new kind of material which extends the duration of optimal performance at 2.4 times today’s technology’s ability. You may see their discovery displayed on the cover of ACS Nano’s April issue.
Two yale engineers named Jan Schroers and André Taylor created microscopic nanowires by adapting a new metal alloy called bulk metallic glass (BMG). Their theoretical uniquity is owed to their unusually high surface area, which is capable of holding a greater volume of the necessary catalyst. This increase in volume increases durability, too.
THIS DIFFERS FROM TRADITIONAL FUEL CELL MATERIAL
Up until this new method, carbon black was used to support platinum particles. Carbon black is relatively cheap and fairly conductive, but the platinum inside of the material is difficult to expose because of how the it’s absorbed. In addition, carbon black corrodes rather quickly.
“In order to produce more efficient fuel cells, you want to increase the active surface area of the catalyst, and you want your catalyst to last,” said Taylor.
HOW SMALL IS BULK METAL GLASS?
BMG Nanowires are only 13 nanometers (roughly 1/10,000 the diameter of a single human hair), which is one-third the size of carbon black particles. Additionally, nanowires’ being so long and exceptionally thin supplies them with a much greater surface area per unit of mass. To boot, instead of installing platinum post-material-hoc, the Yale engineers are able to incorporate platinum directly into the structure of the nanowire alloy, making the new material a synthetic marvel of customized functionality.
NANO-GEOMETRY IS A THING
Because of nanowires specific chemical makeup, the material can be molded into small rods and blown into complex and interesting shapes using a hot-press method.
To date, Taylor’s tested the new catalyst system on alcohol-based fuel cells (e.g. ethanol and methanol), however we will soon see the new fuel cell system tested on versions applicable to such quotidian devices as laptop computers, cell phones and remote sensors.
“This is the introduction of a new class of materials that can be used as electrocatalysts,” added Taylor. “It’s a real step toward making fuel cells commercially viable and, ultimately, supplementing or replacing batteries in electronic devices.”