FeO nanoclusters highly dispersed on a porous graphene support as an additive for improving the hydrogen storage properties of LiBH.

FeO nanoclusters anchored on porous reduced graphene oxide (FeO@rGO) have been synthesized by a one-step hydrothermal route, and then ball milled with LiBH to prepare a hydrogen storage composite with a low onset dehydrogenation temperature, and improved dehydrogenation kinetics and rehydrogenation reversibility. The LiBH-20 wt% FeO@rGO composite begins to release hydrogen at 74 °C, which is 250 °C lower than for ball-milled pure LiBH. Moreover, the composite can release 3.36 wt% hydrogen at 400 °C within 1000 s, which is 2.52 times as high as that of pure LiBH. Importantly, it can uptake 5.74 wt% hydrogen at 400 °C under 5 MPa H, and its hydrogen absorption capacity still reaches 3.73 wt% after 5 de/rehydrogenation cycles. The activation energy ( ) of the hydrogen desorption of the composite is decreased by 79.78 kJ mol when 20 wt% FeO@rGO is introduced into LiBH as a destabilizer and catalyst precursor, showing enhanced thermodynamic properties. It could be claimed that not only the destabilization of FeO, but also the active LiBO species formed , as well as the wrapping effect of the graphene, synergistically improve the hydrogen storage properties of LiBH. This work provides insight into developing non-noble metals supported on functional graphene as additives to improve the hydrogen storage properties of LiBH.