Ammonia borane–polyethylene oxide composite materials for solid hydrogen storage

Abstract

Co-electrospinning ammonia borane (AB) and polyethylene oxide (PEO) has created a unique crystal phase that promotes faster hydrogen release from AB below its melting temperature with no incubation time. Integral fibres have been produced containing 75%, 50% and 25% AB by weight. As the PEO content was increased, the onset temperature of dehydrogenation was reduced from 110 °C for pristine AB to 85 °C for the 25% AB fibres. The new phase is characterised by hydrogen bonding between the hydridic hydrogen atoms bonded to the nitrogen atom in AB and the oxygen atom in the PEO backbone. Additionally, the usual foaming of AB during hydrogen release was effectively controlled by the addition of PEO. Some impurities which accompany the hydrogen release – ammonia and diborane – are reduced, however, borazine levels in the gas stream were observed to increase during the loss of the 2nd hydrogen equivalent. Nevertheless, co-electrospun composites of AB and PEO show great promise as a safe, portable and versatile hydrogen storage material.