A highly efficient hydrolysis of MgH2 catalyzed by NiCo@C bimetallic synergistic effect

• Published in: Journal of materials science & technology 2023-02, Vol.137, p.176-183
• Main Authors: Zhao, Yang, Li, Tong, Huang, Haixiang, Xu, Tingting, Liu, Bogu, Zhang, Bao, Yuan, Jianguang, Wu, Ying
• Format: Article
• Language: English
• Subjects: Hydrogen generation; Hydrolysis; MgH2; NiCo bimetallic catalysts; Reaction kinetics
• ISSN: 1005-0302; 1941-1162
• DOI: 10.1016/j.jmst.2022.08.005

•A NiCo bimetallic catalyzer is significantly efficient to improve hydrolysis performance of MgH2.•Nearly 100% hydrolysis conversion is achieved for MgH2-8 wt% NiCo@C composite.•Low reaction activation energy of MgH2-8 wt% NiCo@C composite is obtained.•Hydrolysis mechanism of MgH2-8 wt% NiCo@C composite for hydrogen production is clarified. MgH2 has a high theoretical hydrogen production capacity and mild conditions for hydrogen production by hydrolysis, so it is suitable as an ideal hydrogen source for fuel cells. However, with the progress of the hydrolysis reaction, MgH2 is impeded from reacting further by the continuous deposition of magnesium hydroxide on its surface, resulting in low hydrogen yield and slow reaction kinetics. In the present work, a highly efficient NiCo bimetallic synergistic catalysis is developed to improve the hydrolysis performance of MgH2. The MgH2-8 wt% NiCo@C composite ball-milled for 5 h achieves nearly 100% hydrogen desorption efficiency within 15 min in 0.05 mol L–1 MgCl2 solution. Because the interaction between Ni and Co on the surface of MgH2 can form a channel for rapid hydrogen evolution, which hinders the continuous formation of the Mg(OH)2 passivation layer and promotes the hydrolysis reaction of MgH2. This is very important for the implementation of MgH2 hydrolysis to produce hydrogen in the future. [Display omitted]