266145 Improved Hydrogen Release From Magnesium Borohydride with Additives

Tuesday, October 30, 2012: 1:20 PM
305 (Convention Center )
Ahmad Al-Kukhun, Hyun Tae Hwang and Arvind Varma, School of Chemical Engineering, Purdue University, West Lafayette, IN

The dehydrogenation properties of magnesium borohydride (Mg(BH4)) with various additives were investigated.  It was found that certain additives can improve the dehydrogenation properties of magnesium borohydride significantly. While neat Mg(BH4)  starts to release hydrogen > 270oC, Mg(BH4) with a specific additive begins hydrogen release ~ 75oC, as confirmed by mass spectrometry and thermogravimetry. The hydrogen yield of Mg(BH4) in the presence of the additive was 3.7, 7.4, 10.0, 11.4 wt% for 150, 250, 300 and 350oC, respectively. Using pXRD, we confirmed that the final crystalline product at 300oC from Mg(BH4)with the additive was Mg, while it was MgH2 for neat Mg(BH4). Solid state 11B NMR analysis of Mg(BH4)with the additive  at 300oC showed high selectivity towards the formation of Mg(B12H12) as intermediate, while neat Mg(BH4) showed β-Mg(BH4), Mg(B2H6) as well as some Mg(B12H12). Our results demonstrate that the additive is a promising one to provide high hydrogen yield values from Mg(BH4) at moderate temperatures < 300oC, suitable for vehicle applications.

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