Feasibility of Fullerene Hydride as a High Capacity Hydrogen Storage Material

The results of recent investigation of fullerene–fullerene hydride system as a potential high capacity hydrogen storage option are presented. Theoretically, C60 fullerenes can reversibly store up to 7.7 wt.% hydrogen by forming fullerene hydride C60Hx. However, high temperature and pressure are currently required to enable hydrogen exchange in this system. For example, direct hydrogenation of fullerenes in the presence of gaseous hydrogen at ~450°C and ~ 3 MPa yields fullerene hydride with ~6.1 wt.% hydrogen content. Over the past years, MER has been searching for practical ways to facilitate hydrogen storage on fullerenes at milder conditions. The main focus of the research was concentrated on optimizing catalytic system including transition-metal liquid state catalysts, as well as modifying electronic structure of fullerenes by doping them with electron-donating elements (for example, alkali metals). As a result of this investigation, certain progress was made in lowering the temperature and pressure required for hydrogenation. However, dehydrogenation parameters still remain to be optimized.