Two scientists from the University
of Wisconsin-Madison have made an important stride in making hydrogen
fuel cell vehicles more viable. The two scientists -- Professor Dane
Morgan and PhD student Edward Holby -- have designed
a computational model that can optimize one of the most important
components of a fuel cell, possibly leading to a longer usable
The computational model is being used to investigate how
the particle size of a material relates to the overall stability of
the material. The researchers are using the model to look at the most
efficient and effective particle size for the catalyst inside the
The fuel cell catalyst is typically made from
platinum or platinum alloy. The catalyst is used to aid the reaction
between the protons, electronics, and oxygen at the cathode inside
the cell. Platinum is able to withstand the corrosive fuel cell
environment but is costly and not available in abundance.
particles used inside current fuel cell catalysts are as small as two
nanometers across. The tiny particles offer enough surface area for
the reaction, but are quickly destroyed and degrade rapidly. The
degradation of the catalyst means that the fuel cell doesn't last
long. The Department of Energy figures that a fuel cell needs to last
for 7 months of continuous use for automotive needs.
computational model developed by the pair has shown that the ideal
particle size for the catalyst is about 20 atoms across, roughly
twice as large as the particles inside fuel cells today. At the
20-atom size, the particles degrade much slower and allow the fuel
cell to function significantly longer.
Morgan likens the
stability of larger particles to cheese, "When you leave a large
chunk of cheese out and the edges get crusty, the surface is
destroyed, but you can cut that off and there is still a lot of
cheese inside that is good. But if you crumble the cheese into tiny
pieces and leave it out, you destroy all of your cheese because a
larger fraction of the cheese is at the surface."
group of researchers made a breakthrough in July with the potential
to make storing
hydrogen for fuel cells more efficient.