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

• Published in: Journal of energy chemistry Vol. 23; no. 6; pp. 726 - 731
• Main Authors: Wang, Ying, Li, Li, Qiu, Fangyuan, An, Cuihua, Wang, Yijing, Jiao, Lifang, Yuan, Huatang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2014; Elsevier
• Subjects: Alternative fuels. Production and utilization; Applied sciences; Chemistry; co-additive; dehydrogenation properties; Energy; Exact sciences and technology; Fuels; Hydrogen; hydrogen storage; Inorganic chemistry and origins of life; Kinetics and mechanism of reactions; Mg(AlH4)2; synergetic effects; Mg(AlH4)2; dehydrogenation properties; co-additive; synergetic effects; hydrogen storage; Sodium Tetrahydroaluminates; Scanning electron microscopy; Hydrogen storage; ); Mg(AlH; X ray diffraction; Synergism; Magnesium Tetrahydroaluminates; Surface structure; Characterization; Additive; Dehydrogenation; Morphology; Thermal analysis; Kinetics; Dehydridation; Titanium III Fluorides
• ISSN: 2095-4956
• DOI: 10.1016/S2095-4956(14)60205-9

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.