Dehydriding Process and Hydrogen–Deuterium Exchange of LiBH4–Mg2FeD6 Composites

Energies

Guanqiao Li¹  Motoaki Matsuo²  Katsutoshi Aoki²  Tamio Ikeshoji²  Shin-ichi Orimo¹ 

[1] WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan; E-Mails:;Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan; E-Mails:

关键词: complex hydride;    borohydride;    isotopic exchange;    hydride composites;    hydrogen storage;   

DOI  :  10.3390/en8065459

来源: mdpi

【 摘 要 】

The dehydriding process and hydrogen–deuterium exchange (H–D exchange) of xLiBH₄ + (1 − x)Mg₂FeD₆ (x = 0.25, 0.75) composites has been studied in detail. For the composition with x = 0.25, only one overlapping mass peak of all hydrogen and deuterium related species was observed in mass spectrometry. This implied the simultaneous dehydriding of LiBH₄ and Mg₂FeD₆, despite an almost 190 °C difference in the dehydriding temperatures of the respective discrete complex hydrides. In situ infrared spectroscopy measurements indicated that H–D exchange between [BH₄]⁻ and [FeD₆]⁴⁻ had occurred during ball-milling and was promoted upon heating. The extent of H–D exchange was estimated from the areas of the relevant mass signals: immediately prior to the dehydriding, more than two H atoms in [BH₄]⁻ was replaced by D atoms. For x = 0.75, H–D exchange also occurred and about one to two H atoms in [BH₄]⁻ was replaced by D atoms immediately before the dehydriding. In contrast to the situation for x = 0.25, firstly LiBH₄ and Mg₂FeD₆ dehydrided simultaneously with a special molar ratio = 1:1 at x = 0.75, and then the remaining LiBH₄ reacted with the Mg and Fe derived from the dehydriding of Mg₂FeD₆.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.