Materials and manufacturing boost for hydrogen storage

It is claimed the researchers have, for the first time, created compounds made from mixtures of calcium hexaboride, strontium and barium hexaboride. They also have demonstrated that the compounds could be manufactured using combustion synthesis, a simple, low-cost manufacturing method.

The work is at the proof of concept stage and is part of a $1.2m project funded by the US National Science Foundation, a collaboration between UC San Diego (UCSD), Alfred University in New York State and the University of Nevada, Reno.

The researchers presented their work in March 2014 at the third International Symposium on Nanoscience and Nanomaterials in Mexico.

Storing hydrogen has become increasingly important, as hydrogen fuel cells become more popular power sources in industry and elsewhere. Hydrogen, however, is difficult to store as it tends to diffuse through the walls of pressurised tanks. It also needs to be compressed in order to occupy manageable amounts of space when stored.

According to UCSD, the resulting ceramics are essentially crystalline structures in a cage of boron. To store hydrogen, the researchers would swap the calcium, strontium and boron with hydrogen atoms within the cage.

During the combustion synthesis process, engineers mixed boron with metal nitrates and organic fuels, such as urea, in a box furnace at temperatures below 400 degrees Celsius. The nitrates and organic fuels ignite, generating heat that then drives the reaction without the need for an external source of power.