Neutrons unlock properties of novel porous metal-hydride for possible new energy storage applications

Separating gases such as hydrogen from larger compounds in the air is an important part of manufacturing and energy production. But it's also an expensive process, requiring large amounts of energy and a complicated network of heavy machinery in order to be profitable.

Yaroslav Filinchuk, a professor of chemistry from the Universite Catholique de Louvain, Belgium, and Michael Heere, a researcher from the Karlsruhe Institute of Technology and affiliate of the Forschungsreaktor München II research reactor in Munich, Germany, may have a solution to this problem. Using neutron scattering at the Department of Energy's (DOE's) Oak Ridge National Laboratory (ORNL), Filinchuk and Heere are investigating a material that could change the way we harvest valuable industrial materials.

"We have a unique material. It's the first porous metal hydride material in its unique class," said Filinchuk. "We've got a sample here [Mg(BH4)2], and we're trying to expose it to different gases to see if we can better understand how it absorbs those gases."

A complex metal hydride is a compound material made up of bound-together atoms of hydrogen and metal. Metal hydrides are common in certain batteries, where they're used to store hydrogen. But the pores in magnesium borohydride make it a particularly good tool for hydrogen storage, allowing the substance to take in a huge amount of hydrogen—more than twice the amount found in liquid hydrogen. What's more, those pores are the perfect size for filtering molecules like krypton and xenon from each other or from larger compounds, potentially eliminating the need for the heavy refrigeration equipment currently used to cool, capture, separate, and store industrial gases.

"When you've got something that can store this much hydrogen and potentially isolate valuable industrial gases, it's pretty exciting," said Heere.