Scientists at the University of New South Wales (UNSW), Australia, are developing a novel way to store hydrogen that could help turn it into a viable portable fuel source.
The research centers on using synthesized nanoparticles of the compound sodium borohydride (NaBH4 for those who love chemistry), which when encased inside nickel shells exhibits surprising and practical storage properties including the ability to reabsorb hydrogen and release it at much lower temperatures than previously observed, making it an attractive proposition for transport applications.
Hydrogen is a clean burning fuel that can be extracted from sources including natural gas, biomass, coal and water. One of the major problems in making it a viable alternative fuel is storage – the atoms are so tiny that they can easily escape from many kinds of containers. Also, hydrogen is more volatile than petrol. It can burn like blazes and can react badly to other substances. As no one wants to have a car that can burst into flames when you switch on the engine, this problem has drawn the attention of scientists around the world.
The new findings indicate that by controlling the size and architecture of these structures, their properties can be made reversible. In other words, NaBH4 absorbs the hydrogen like a sponge and then releases it, making it useful for application in vehicles. In its bulk form, sodium borohydride requires temperatures above 550°C just to release hydrogen. It’s pretty much the same even on the nano-scale, but this core-shell nanostructure saw energy release happening at just 50°C, and significant release at 350°C.