Effects of TiO2 and Nb2O5 on Hydrogen Desorption of Mg(BH4)2

In this work, effects of catalysts (TiO2, and Nb2O5) were investigated on the hydrogen desorption of Mg(BH4)2. LiBH4 and MgCl2 with 2:1 molar ratio were mixed by using ball milling to prepare Mg(BH4)2. The desorption behaviors were measured by thermo-volumetric apparatus. The hydrogen desorption capacity of the mixed sample milled for 2 h was 4.78 wt% with a 2-step released. The first step occurred at 214 °C and the second step appeared at 374 °C. The addition of 16 wt% Nb2O5 decreased the desorption temperature in the second step about 66 °C and increased the hydrogen desorption capacity to 4.86 wt% hydrogen. The addition of TiO2 also improved the desorption temperature in the second step and the hydrogen desorption capacity. It decreased the desorption temperature about 71°C and showed a high amount of hydrogen, 5.27 wt%, released from the mixed sample. The hydrogen absorption after desorption of Mg(BH4)2 was also studied under 9.5 MPa and 350 °C for 12 h.

• Wipada Ploysuksai
• Pramoch Rangsunvigit
• Santi Kulprathipanja

• hydrogen storage
• LiBH4
• metal hydride
• Mg(BH4)2

[1] Ye, X., An, Y., and Xu, G. (2011). Kinetics of 9 -
ethylcarbazole hydrogenation over Raney-Ni catalyst for
hydrogen storage. Journal of Alloys and Compounds, 509,
152-156.
[2] Dong, J., Wang, X., Xu, H., Zhao, Q., and Li., J. (2007).
Hydrogen storage in several microporous zeolites.
International Journal of Hydrogen Energy, 32, 4998-5004.
[3] Hu, X., Fan, M., Towler,B.F., Radosz M., and Bell, D. A.
(2011). Chapter 8 Hydrogen Adsorption and Storage. Coal
Gasification and Its Applications., 188.
[4] Sakintuna, B., Darkrimb, F. L., Hirscherc, M. (2007). Metal
hydride materials for solid hydrogen storage: A review.
International Journal of Hydrogen Energy, 32, 1121-1140.
[5] Pistidda, C., Garroni, S., Dolci, F., Bardají, E. G., Khandelwal,
A., Nolis, P., Dornheim, M., Gosalawit, R., Jensen, T.,
Cerenius, Y., Suriñach, S., Baro, M. D., Lohstroh, W., and
Fichtner, M. (2010). Synthesis of amorphous Mg(BH4)2 from
MgB2 and H2 at room temperature. Journal of Alloys and
Compounds, 508, 212-215.
[6] Zhang, Z.G., Zhang, S.F., Wang, H., Liu, J.W., and Zhu, M.
(2010). Feasibility study of the direct synthesis of Mg(BH4)2
complex hydrides by mechanical milling. International Journal
of Hydrogen Energy, 505, 717-721.
[7] Matsunaga, T., Buchter, F., Miwa, K., Towata, S., Orimod, S.,
and Züttel, A. (2008). Magnesium borohydride: A new
hydrogen storage. Renewable Energy, 33, 193-196.
[8] Matsunaga, T., Buchter, F., Mauron, P., Bielman, M.,
Nakamori, Y., Orimoc, S., Ohba, N., Miwa, K., Towata, S., and
Züttel, A. (2008). Hydrogen storage properties of Mg(BH4)2.
Journal of Alloys and Compounds, 459, 583-588.
[9] Li, H.-W., Kikuchi, K., Nakamori, Y., Miwa K, Towata, S., and
Orimo, S. (2008). Effects of ball milling and additives on
dehydriding behaviors of well-crystallized Mg(BH4)2. Scripta
Materialia, 57, 679-682.
[10] Friedrichs, O., Klassen, T., Sánchez-López, J.C., Bormann, R.,
Fernández, A. (2006). Hydrogen sorption improvement of
nanocrystalline MgH2 by Nb2O5 nanoparticles. Scripta
Materialia, 54, 1293-1297.