Hydrogen fuel cells need catalysts to accelerate the chemical reactions inside them, but the problem is that they are very expensive because the catalysts are made of precious materials like platinum. The new catalyst is based on iron, nitrogen, and carbon which are far less expensive than platinum which ranges between $1,000 to $2,000 an ounce. Although these three non-precious materials were used for hydrogen fuel cells before, they didn’t react too well making the cells unpractical.
Researchers at the Institut National de la Recherche Scientifique, Quebec have managed to increase the power of the catalyst to 99 amps per cubic centimeter at .8 volts which is 35 times better than previous iron-based catalysts. With just a few improvements the INRS scientists should soon reach the 130 amps per cubic centimeter, which is the minimum amount for hydrogen fuel cell catalysts. According to Jean Pol Dodelet, leader of the INRS team, this iron-based catalyst is just as good as platinum catalysts which means that hydrogen fuel cells will become cheaper, and in time, better.
“We thought nobody would ever meet [the benchmark for hydrogen fuel cells]. For the very first time, a non-precious metal catalyst makes sense,” said Hubert Gasteiger, Professor of Mechanical Engineering at MIT. Gasteiger is only one of the researchers who praised INRS’ breakthrough which is “quite surprising” if it were to quote Radoslav Adzic, researcher and fuel cell catalysts-developer at the Brookhaven National Laboratory.
Although other researchers have tried, the INRS team used a different approach, and they increased the number of the catalytic sites in the iron-based material. They figured that if they would have more active sites, then the number of reactions within the material will increase. These catalytic sites are “obtained” by heating a graphite-like form of carbon called carbon black which reacts and creates “gaps” when in contact with ammonia and iron acetate. Then the researchers used nitrogen atoms to link gaps’ opposite sides which eventually result in active catalytic sites.
According to Dodelet, their iron-based catalyst performs best in PEM fuel cells which work at low temperatures, and feature a high power density. He also said that there are other non-precious metal-based catalysts which work in alkaline cells, however, these catalysts will not operate in an acidic environment like the one found in PEM fuel cells.
“We solved the problem,” said Dodelet, but he admits that the catalyst needs further improvements because it has two major flaws – the former is its durability which has to be increased as after 100 hours, the reactions in the cells were halved; and the latter is the fact that catalysts can operate as fast as the reactants allow them, but the oxygen and protons transportation will have to be improved by fuel cell engineers as Dodelet’s team only develops the catalysts.
I don’t think that it will take too long before these obstacles will be overcome, and it is quite possible that in the near future automakers will get their hands on cheaper hydrogen fuel cells which means that we will be able to buy hydrogen cars at lower prices.