Nanocage aims to trap and release hydrogen on demand

Hydrogen has long been seen as a low-carbon replacement for fossil fuels in transportation. However, as a low-density gas, it is difficult to store safely and compactly within vehicles.

Now researchers at Bristol University, funded by the EPSRC, are developing composite materials capable of adsorbing hydrogen gas and storing it at high densities, within nanometre-sized pores.

What’s more, the materials are being used to allow trapping and release of the hydrogen molecules on demand, according to Dr Valeska Ting, Reader in Smart Nanomaterials at Bristol University.

“Hydrogen is a gas at room temperatures and pressures, so if you want to carry it around it takes up a lot of volume,” said Dr Ting.

This has prompted research into porous materials such as nanostructured carbons, metal-organic frameworks or zeolites, which have a high surface area. These materials act like a sponge, sucking in the hydrogen and storing it in nanometre-sized pores at far higher densities than is possible in gas form.