TY - JOUR
T1 - Interaction of metallic magnesium with ammonia
T2 - Mechanochemical synthesis of Mg(NH2)2 for hydrogen storage
AU - Hu, Mengru
AU - Sun, Xin
AU - Li, Bo
AU - Li, Peng
AU - Xiong, Meichai
AU - Tan, Jun
AU - Ye, Zhangze
AU - Eckert, Jürgen
AU - Liang, Chu
AU - Pan, Hongge
N1 - Publisher Copyright: © 2022 Elsevier B.V.
PY - 2022/6/25
Y1 - 2022/6/25
N2 - 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.
AB - 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.
KW - Ammonia
KW - Hydrogen storage
KW - Magnesium amide
KW - Mechanical milling
KW - Metallic magnesium
UR - http://www.scopus.com/inward/record.url?scp=85126089258&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2022.164397
DO - 10.1016/j.jallcom.2022.164397
M3 - Article
AN - SCOPUS:85126089258
SN - 0925-8388
VL - 907.2022
JO - Journal of alloys and compounds
JF - Journal of alloys and compounds
IS - 25 June
M1 - 164397
ER -