Researchers at the U.S. Department of Energy’s SLAC National Accelerator Laboratory along with the University of Houston have created a new form of platinum that might be utilized in fuel cells to make them cheaper and more efficient.
“This is a significant advance,” said researcher Anders Nilsson of the Stanford Institute for Materials and Energy Sciences, a joint institute between SLAC and Stanford University. “Fuel cells were invented more than 100 years ago. They haven’t made a leap over to being a big technology yet, in part because of this difficulty with platinum.”
The platinum difficulty to which Nilsson refers is that fuel cells require as much as 100 grams of platinum, which can send the cost of production into the thousands of dollars.
According to the SLAC, fuel cells function similarly to batteries. A metal cathode collects electrons from an anode in an electrical circuit. In a fuel cell, however, the energy is produced through chemical reactions involving hydrogen and oxygen. The choice of metal used in the cathode is very important because some metals cannot break apart the oxygen atoms, and others bind too strongly to the oxygen atoms and interfere with the reaction. A good metal provides a “balance point,” where the number of oxygen bonds broken is maximized and the bonds between the metal and the oxygen atoms are weak. Platinum achieves this balance but at a high cost.
In the April 25th issue of Nature Chemistry, the research team described how they used a chemical process called dealloying, which involved the combination of platinum with various amounts of copper to create copper-platinum alloys. Then, they removed the copper from the surface regions of the alloy and tested the binding properties of the newly created metal. The researchers discovered a much more highly reactive catalyst that could potentially be used as the cathode in fuel cells.
Ultimately, this discovery will contribute to making hydrogen fuel cell electric vehicles more affordable and attainable.
“Research has shown that this new catalyst is as much as five times more active than pure platinum,” said Nilsson. “This means that we would only need one-fifth the amount of platinum compared to current fuel cells for the same overall performance. Consequently, the cost of fuel cell vehicles could be reduced significantly.”