Gen-next material to better store hydrogen fuel in cars

Researchers have designed next-generation materials that could be used to store hydrogen fuel more efficiently and economically in vehicles or other devices that run on clean energy.
Using complex mathematical equations and computer simulations, the researchers designed porous materials of transition metals - compounds involving cobalt, iron or nickel - that cause hydrogen to bond with it.
The next-generation design could then be placed in a tank of a car that uses hydrogen for fuel. These new materials are made of Earth abundant elements and therefore are easily available.
"There will be many proposals to solve energy issues, and this may be one option," said Jose Mendoza-Cortes, assistant professor at the Florida State University in the US.

"We wanted to find the most effective way to store hydrogen so that perhaps in the future, cars could use this to run longer distances and more efficiently," he said.
Scientists had already discovered that they needed to pressurise hydrogen to compact it and make it usable as a fuel for cars.

However, Mendoza-Cortes wanted to take it one step further and make the process more efficient and economically viable.
"We still want to pressurise it, but we want to do it more efficiently. Right now, it is extremely costly to do this," he said.
Mendoza-Cortes designed 270 compounds through these simulations and then tested their performance for hydrogen storage.

The idea is that since hydrogen will bind to the actual device, more hydrogen could be packed in and condensed into a tank. Because the hydrogen easily sticks to the device, the tank would never actually reach empty.
Additionally, he found it would take a smaller energy expenditure to fill up the tank.
"In other words, more hydrogen can be stored at lower pressures and room temperature, making some of these materials good for practical use," Mendoza-Cortes said.
Currently, hydrogen can be made into liquid at 1 bar - bar is the unit of measurement for atmospheric pressure - and minus 253 degrees Celsius.

At that rate, hydrogen can be stored at 71 grams per litre. While at 700 bar and 25 degrees Celsius, hydrogen can be stored at 37 grams per litre.
With Mendoza-Cortes' proposed new materials, hydrogen could be stored at less than 200 bar to fill up the same tank at room temperature, creating a far more efficient system.
"You do not have to spend all that energy to get the same amount of storage," he said.
The study appears in the Journal of the American Chemical Society.