Mechanistic insight into the promoting effect of magnesium nickel hydride on the dehydrogenation of ammonia borane. (18th January 2018)

• Record Type: Journal Article
• Authors: Luo, Junhong; Wang, Jinchuan; Feng, Xingwen; Cai, Jinguang; Yao, Weizhi; Song, Jiangfeng; Chen, Changan; Luo, Deli
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 3(2018)
• Page Start: 1681
• Page End: 1690
• Publication Date: 2018-01-18
• Subjects: Ammonia borane -- Metal hydride -- Hydrogen storage -- Dehydrogenation; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.12.005
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this paper, we report an in-depth study of the post-milled 4AB/Mg2 NiH4 sample, with a special focus on the promoting mechanism of Mg2 NiH4 on the dehydrogenation of AB. A combination of X-ray diffraction (XRD), Fourier transformation infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) characterizations, together with selective isotopic labelling and other designed experiments, revealed that AB and Mg2 NiH4 react with each other from the starting phase of the dehydrogenation process, which eventually results in the formation of MgNiBNH complexes. On the other hand, it was found that the reaction between AB and Mg2 NiH4 cannot proceed directly, but requires phase transition of normal AB to its mobile phase AB* to occur first. Hence, the promoting mechanism of Mg2 NiH4 on the dehydrogenation of AB is attributed to its promoting effect on phase transition of normal AB to AB* under mild conditions and in particular its chemical modification of AB with Mg and Ni. Graphical abstract: Highlights: The promoting mechanism of Mg2 NiH4 on the dehydrogenation of NH3 BH3 is proposed. Mg2 NiH4 firstly promotes phase transition of NH3 BH3 to its mobile phase NH3 BH3 *. Mg2 NiH4 then reacts with NH3 BH3 * to generate MgNiBNH complexes. The formation of MgNiBNH complexes accounts for the property improvement.