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Cheap hydrogen fuel cells thanks to a catalyst that eliminates platinum – Technology – Hybrids and Electric

An new catalyst created by a Cornell University team of scientists in the United States could replace the current platinum which is used to speed up the oxygen reduction reaction in hydrogen fuel cells. According to its creators, this cobalt nitride catalyst has a cost 475 times lower than platinum that is currently used, which could make the systems cheaper in such a way that it would help this technology to become popular already stimulate the creation of a charging network.

Hydrogen fuel cell technology has two fundamental handicaps to overcome. The one that is always named as a great inconvenience for its popularization is the scarce existing hydrogen supply network. The system requires a network similar to the one that exists today with service stations, which is complex and expensive to implement. And it is even more so if one takes into account the vehicle shortage that move with this fuel, which makes the economic viability of businesses dedicated to refueling almost impossible. In addition, to achieve the sustainability of the process, the hydrogen must be green, that is, created by hydrolysis using renewable energies. The second handicap, also very important, is the cost of fuel cell systems, which also require pressurized hydrogen tanks for their transport. fuel cell itself.

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Diagram of operation of the hydrogen supply network. Image: Hyvia.

So the Cornell researchers’ discovery may become an incentive for this technology. Within a fuel cell, hydrogen reacts with oxygen to generate electricity, scrubbing only water as the final waste. One of the key elements that acts within it is the platinum. This precious metal is used as a catalyst in the oxygen reduction reaction. That is, since it is a slow process, platinum helps speed it up. Your problem is that it is an element very expensive and, in addition, Russia is one of its main producers. The catalyst discovered by the Cornell researchers is 475 times cheaper than platinum (a data from February 2, 2022, when this study was published prior to the invasion of Ukraine).

The TMN (transition metal nitrides) are derivatives of non-precious metals that are made from manganese, iron, and cobalt. According to the main author of the research, Héctor D. Abruña, the cobalt nitride catalyst is “the clear winner”. But sadly, cobalt is not a readily available or controversy-free metal, as battery manufacturing shows.

The catalyst the researchers developed works well with alkaline fuel cells which are among the most promising of the top five technologies out there. These work at room temperature and have an efficiency of up to 70%. The other four are PEM (proton exchange membrane), PAFC (phosphoric acid fuel cell), MCFC (molten carbonate fuel cell) and SOFC (solid oxide fuel cell).

If fuel cell manufacturers adopted the cobalt nitride catalyst and produced it in large enough quantities, they could replace platinum while lowering the final cost of the technology. That would favor the production of these fuel cells at competitive prices so that they could be implemented in mass-produced vehicles. With the increasing demand, probably, the network of hydrogen stations would be increased throughout the world.

Hydrogen fuel cell “plug-in hybrids”

In addition to heavy transport, in which case the use of batteries is complicated by the weight and volume that would be needed, another interesting application of the hydrogen fuel cell is to hybridize power supplies. It would be a “plug-in hybrid”, although not in the sense that is currently adopted for this technology in which a combustion engine and an electric one coexistthat is, the propulsion is hybridized, not the feeding.

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Schematic of a hydrogen fuel cell plug-in hybrid. Image: Hyvia.

It would be a vehicle equipped with two electricity production systems. A medium-capacity battery, with autonomy of up to 200 kilometers rechargeable in the electrical network, would allow daily trips depending only on linked or opportunity recharging and without the need to use hydrogen. For longer trips, the network of hydrogen generators located on the highways, which would mainly serve trucks, would allow these vehicles to refuel with hydrogen to increase their autonomy.

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