[If you’re new to the subject, read how fuel cells work first]
Nowadays, the cost of a hydrogen fuel cell is mostly increased by the cost of its components, and mostly by platinum. In the search for finding better materials for making fuel cells, researchers have already found alternatives to the expensive platinum a long time ago, but they were not as efficient. One of this substitute materials is palladium – far cheaper and much more abundant, but that didn’t have enough surface area to make the fuel cell catalysis efficient.
The researchers from Brown University have found a way to increase the surface of the palladium by creating bigger nanoparticles – 40% more surface than commercially available particles. Also, these palladium particles remain intact four times longer than the currently available ones.
“This approach is very novel. It works,” said Vismadeb Mazumder, a graduate student who joined chemistry professor Shouheng Sun on the paper. “It’s two times as active, meaning you need half the energy to catalyze. And it’s four times as stable.”
The newly invented particles have 4.5 nanometers in size and are attached to a carbon platform at the anode end of a direct formic acid fuel cell. The researchers then did something new: They used weak binding amino ligands to keep the palladium nanoparticles separate and at the same size as they’re attached to the carbon platform. By keeping the particles separate and uniform in size, they increased the available surface area on the platform and raised the efficiency of the fuel cell reaction.