Synergetic effects of NaAlH4-TiF3 co-additive on dehydriding reaction of Mg(AlH4)2

The effects of NaAlH4, TiF3 and NaAlH4-TiF3 co-additive on dehydriding reaction of Mg(AlH4)2 are systematically investigated. The onset dehydrogenation temperature of the co-doped Mg(AlH4)2 composites decreased to 74 °C, which is about 59 °C lower than that of pure Mg(AlH4)2. The dehydrogenation kinetics of NaAlH4-TiF3 co-doped Mg(AlH4)2 sample was also improved, which released about 94% hydrogen within 48 min, but no visible hydrogen was released from pure Mg(AlH4)2 under the same conditions. The activation energy of co-doped Mg(AlH4)2 was 85.6 kJ-mol−1, which was significantly lower than that of additive-free Mg(AlH4)2 sample. The synergetic effects of NaAlH4 and TiF3 on the dehydrogenation performance of Mg(AlH4)2 were confirmed. In addition, a possible catalytic mechanism is discussed, regarding the different roles of NaAlH4 and TiF3 on Mg(AlH4)2.

NaAlH4-TiF3 co-additive shows synergistic effects on the dehydrogenation properties of Mg(AlH4)2, which can effectively decrease the onset desorption temperature of Mg(AlH4)2.Figure optionsDownload full-size imageDownload as PowerPoint slide