Interaction of metallic magnesium with ammonia: Mechanochemical synthesis of Mg(NH2)2 for hydrogen storage

Mengru Hu, Xin Sun, Bo Li, Peng Li, Meichai Xiong, Jun Tan, Zhangze Ye, Jürgen Eckert, Chu Liang, Hongge Pan

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung

3 Zitate (Scopus)


Mg(NH2)2-2LiH is one of the most promising hydrogen storage systems to be applied in hydrogen powered vehicles as hydrogen source. However, the synthesis of the main raw material Mg(NH2)2 is high-cost and time-consuming for the present technologies. Herein, we report a low-cost, time-saving and low-carbon method to synthesize Mg(NH2)2 by mechanochemical reaction of metallic Mg with ammonia. After 72 h of mechanochemical reaction, amorphous Mg(NH2)2 is successfully synthesized by milling metallic Mg and ammonia at room temperature. A two-stage reaction is demonstrated to be responsible for the conversion of Mg and ammonia into Mg(NH2)2. In the initial process of ball milling, Mg particles tend to clump and agglomerate because of the ductility of metallic Mg. The first reaction stage between metallic Mg and ammonia occurs at the surfaces and interfaces of bulk Mg to form MgH2 and Mg(NH2)2 powders. With prolonged milling time, the size of bulk Mg decreases with milling time due to the continuous occurrence of the first-stage reaction. The second-stage reaction is confirmed to be the reaction of MgH2, developed in the first reaction stage, with ammonia to produce Mg(NH2)2. The as-synthesized Mg(NH2)2 is used as raw material for synthesizing Mg(NH2)2-2LiH material, showing almost the same hydrogen storage performance as the Mg(NH2)2 synthesized by heating Mg and ammonia. This study provides a new method to synthesize Mg(NH2)2 for hydrogen storage on a large scale.
FachzeitschriftJournal of alloys and compounds
Ausgabenummer25 June
Frühes Online-Datum2 März 2022
PublikationsstatusVeröffentlicht - 25 Juni 2022

Bibliographische Notiz

Funding Information:
This work was financially supported by the Zhejiang Provincial Natural Science Foundation of China (No.: LY19E010007 ) and the National Natural Science Foundation of China (No.: 52072342 ). J.E. acknowledges additional support by the Ministry of Science and Higher Education of the Russian Federation in the framework of the Increase Competitiveness Program of NUST "MISiS" (grant number K2–2020-046 ).

Publisher Copyright:
© 2022 Elsevier B.V.

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