Scientists in Australia are helping to bring hydrogen fuel-cell vehicles closer to the masses through a revolutionary new design that eliminates the need for expensive platinum in fuel-cell catalysts.
The breakthrough at Victoria-based Monash University, seen as potentially making FCVs more reliable and cheaper to build, revolves around an electrode design that employs the special plastic coating used to give Gore-Tex high-performance outdoor clothing its unique, water-resistant properties.
Just as Gore-Tex has revolutionized the outdoor clothing industry, it could hold similar promise for motorists, Monash University’s Bjorn Winther-Jensen says in a statement.
Key to the development is the creation of what the university calls an air-electrode, in which a breathable fabric is coated with a fine layer – just 0.4 microns, or about 100 times thinner than a human hair – of highly conductive plastic that acts as both the fuel-cell electrode and catalyst.
“The same way as waste (water) vapor is drawn out of this material to make hikers more comfortable and less prone to hypothermia, so it is able to ‘breathe’ oxygen into our fuel cell and into contact with the conductive plastic,” Winther-Jensen says.
Monash University Professor Doug MacFarlane, from the Australian Center for Electromaterials Sciences (ACES), says the discovery is probably the most important development in fuel-cell technology in the last 20 years, in that the new design removes the need for exotic platinum, which acts as the catalyst and currently is central to fuel-cell manufacturing.
“Our reliance on platinum is making the likelihood of using fuel cells in everyday passenger cars increasingly improbable,” he says. “The cost of the platinum component, alone, in current fuel cells for a small car with a 134-hp electric engine is more than the total cost of a 134-hp gasoline engine.”
In addition, global production of the precious metal only is sufficient to support a fuel-cell vehicle fleet a fraction of the size of the world’s current annual output of vehicles, MacFarlane says.
The new fuel cell has been continuously tested for periods of up to 1,500 hours using hydrogen as the fuel source.
Professor Maria Forsyth, director of ACES at Monash, says evaluations have shown no sign of material degradation or deterioration in performance.
In addition, testing confirms oxygen-conversion rates are comparable with platinum-catalyzed electrodes of the same geometry, as well as shows the electrodes are not poisoned by carbon monoxide the way platinum is.
“The small amounts of carbon monoxide that are always present in exhausts from petrol (gasoline) engines are a real problem for fuel cells because the platinum catalyst is slowly poisoned, eventually destroying the cell,” Forsyth says.
“The important point to stress is that the team has come up with an alternative fuel-cell design that is more economical, more easily sourced, outlasts platinum cells and is just as effective.”
