Thermal decomposition of alkaline-earth metal hydride and ammonia borane composites

✍ Scribed by Yu Zhang; Keiji Shimoda; Hiroki Miyaoka; Takayuki Ichikawa; Yoshitsugu Kojima

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 501 KB
• Volume: 35
• Category: Article
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2010.08.018

✦ Synopsis

We demonstrate a method to improve the promising hydrogen storage capabilities of ammonia borane by making composites with alkaline-earth metal hydrides using ballmilling technique. The ball-milling for the mixtures of alkaline-earth metal hydride (MgH 2 or CaH 2 ) and ammonia borane (AB) yields a destabilization compared with the ingredient of the mixture, showing the hydrogen capacity of 8.7 and 5.8 mass% at easily accessible dehydrogenation peak temperatures of 78 and 72 C, respectively, without the unwanted by-product borazine. Through detailed analyses on the dehydrogenation performance of the composite at various ratios in the hydride and AB, we proposed a different chemical activation mechanism from that in the LiH/AB and NaH/AB systems reported in a previous literature.