Compared to gasoline, hydrogen is lightweight, has a higher energy density and has a variety of potential sources, like biomass. It sounds great, but there are a few drawbacks. Hydrogen-air mixtures can ignite with very low energy input. If air and hydrogen were to mix in an enclosed space, like a parking lot, a hydrogen leak could easily lead to an explosion if a flame was sparked. Due to hydrogen’s low energy ignition, hydrogen must be safely and densely stored.
In the past, researchers have managed to lock hydrogen into solids, packing larger quantities into smaller volumes with low reactivity. The problem was that most of the solids could only absorb a small amount of hydrogen and required a lot of heating or cooling to boost their energy efficiency.
But now, scientists with the U.S. Department of Energy Berkeley Lab have managed to design a new composite material for storing hydrogen that’s made of nanoparticles of magnesium metal. The nanoparticles are sprinkled through a matrix of polymethyl methacrylate, which is a polymer related to Plexiglas. The material can absorb and release hydrogen without oxidizing the metal, which was a problem in the past. It is also able to do this at more modest temperatures, allowing for greater energy efficiency, which could lead to a major breakthrough for hydrogen storage, batteries and fuel cells.
The research is reported in a paper appearing in the journal Nature Materials.[Nature Materials via PhysOrg]