Fuel cells are an old technology. Dating back to the first half of the nineteenth century, we don't lack for experience or research into the idea of an anode and a cathode surrounding an electrolyte. What we have lacked during that entire period is a balance between the best energy output with economically viable materials. Varying metals for the cathode have been tried, but platinum is among the most efficient of the possibilities. Platinum, of course, is expensive.
Researchers led by Anders Nilsson at Stanford are taking an interesting tack at that problem. Rather than searching out other sources for the cathode, they have figured out a process that can increase platinum's reactivity. So far, according to a paper in Nature Chemistry, they have changed the metal's properties to the extent that 80 percent less platinum would be needed for a fuel cell.
They achieved this feat by combining platinum with copper and then removing the copper on the surface of the alloy. This created lattice strain, or a compressing of the platinum atoms closer together than normal, increasing their reactivity and weakening bonds to oxygen atoms (which occurs in fuel cell reactions).
"The distance between two neighboring atoms affects their electronic structure," said Peter Strasser, another author on the paper, in a press release. "By changing the interatomic distance, we can manipulate how strongly they form bonds." According to the release the investigators hope to eventually "create a potential replacement not only for gasoline engines but also for the batteries found in small electronic devices." Ambitious, to be sure.
Reducing the amount of platinum needed for a fuel cell would clearly bring down the cost, but there are plenty of other methods being sought out to move fuel cells toward widespread implementation. From gold particles to improve platinum's performance to the use of a far cheaper iron-sulfur complex, there is no shortage of ideas. Of course, we've had since 1838 to work on fuel cells, so one would hope we have made some progress.
Photo via NASA/Wikimedia Commons.