Dehydrogenation of LiBH4 Destabilized with Various Oxides

Lithium borohydride is a promising candidate for hydrogen storage and fuel cell application due to its high hydrogen content. In the present work, the effect of various oxides on the dehydrogenation of LiBH4 was investigated. The MS-TG results showed that the LiBH4/oxide mixtures were able to dehydrogenate at much lower temperatures; for example, the onset of dehydrogenation was below 100 °C for a LiBH4−Fe2O3 mixture with a mass ratio of 1:2, and the majority of the hydrogen (∼6 wt %) could be released after heating to 200 °C. The order of destabilization effect for LiBH4 for the studied oxides was Fe2O3 > V2O5 > Nb2O5 > TiO2 > SiO2. XRD results revealed that the destabilization of LiBH4 by the oxides resulted from a redox reaction of LiBH4 + MOx → LiMOx + B + 2H2. Investigation of mixed metal oxides showed that a TiO2/SiO2 sample produced an even greater effect, decreasing the temperature of hydrogen release from LiBH4 by more than either TiO2 and SiO2 alone.