Stabilising on-board refuelling

Performing quantum calculations on a supercomputer, scientists at Pacific Northwest National Laboratory have characterised a material that might allow on-board refuelling of hydrogen powered vehicles.

Researchers, led by Maciej Gutowski, looked at different crystalline structures of a compound made up of nitrogen, boron and hydrogen – NBH6 – and found one that might be more stable compared to ammonia borane, a molecular crystal built of NH3BH3 molecules.

Ammonia borane can hold a lot of hydrogen but isn’t easily reversible, or able to be refilled with hydrogen. Ammonia borane, as a storage material, would likely have to be removed from the vehicle and be sent to some sort of processing plant and undergo a reaction to be refilled.

The more stable compound, diammoniate of diborane or DADB, holds more promise for reversibility. Initial thermodynamic properties for the compound indicate that it might spontaneously uptake hydrogen fuel.

This work is performed under the Grand Challenge Project “Computational studies of materials to hydrogen storage” in the Molecular Sciences Computing Facility at PNNL. Researchers plan to perform additional calculations, synthesise the diammoniate of diborane compound and test their theories on the material in the coming year.