Pure platinum with thin fixed foils of yttrium have been used to create the new nanoalloys that are 10 times as effective as pure platinum in fuel cells. Photo: Mia Halleröd Palmgren.A new type of nanocatalyst could lead to a long-awaited commercial breakthrough in fuel cell-powered cars. Researchers from Chalmers University of Technology in Sweden and the Technical University of Denmark have shown that it is possible to significantly reduce the need for platinum, a precious and rare metal, in fuel cells by creating a nanoalloy using a new production technique. Described in a paper in Advanced Materials Interfaces, the technique is also well suited for mass production.
Even though fuel cells have been around for about 50 years, technological advances have not yet led to a commercial breakthrough. Part of the reason for this is that the catalysts in today’s fuel cells require large amounts of platinum, which is one of the world’s most expensive metals.
“A nano solution is needed to mass-produce resource-efficient catalysts for fuel cells,” says Björn Wickman, a researcher in the Department of Physics at Chalmers University of Technology. “With our method, only one tenth as much platinum is needed for the most demanding reactions. This can reduce the amount of platinum required for a fuel cell by about 70%.”
If this level of efficiency could be replicated in a commercial fuel cell, the amount of required platinum would be comparable to that used in an ordinary car catalytic converter. “Hopefully, this will allow fuel cells to replace fossil fuels and also be a complement to battery-powered cars,” says Wickman.
Previous research had shown that it is possible to mix platinum with other metals, such as yttrium, to reduce the amount of platinum in a fuel cell. Even so, no one had yet managed to create alloys with these metals in both a nanoparticle form and a manner that can be used for large-scale production. The main problem has been that yttrium tends to oxidize instead of forming an alloy with the platinum.
This problem has now been solved by Chalmers researchers by combining the metals in a vacuum chamber using a technique called sputtering, which involves directing plasma at a piece of platinum containing small attached pieces of yttrium. The result is a nanometer-thin film of the new alloy that could lead to mass-produced platinum and yttrium fuel cell catalysts.
To use the new material, today’s fuel cells will need to change slightly, but doing so creates new opportunities.
“When we can use our resources better, we save both the environment and lower costs. Fuel cells convert chemical energy into electrical energy using hydrogen and oxygen – with water as the only product. They have huge potential for sustainable energy solutions in transport, portable electronics and energy,” says Niklas Lindahl, a researcher in the Department of Physics at Chalmers.
This story is adapted from material from Chalmers University of Technology, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.