MgCl2 promoted hydrolysis of MgH2 nanoparticles for highly efficient H2 generation

• Published in: Nano energy Vol. 10; pp. 337 - 343
• Main Authors: Chen, Jun, Fu, He, Xiong, Yifu, Xu, Jinrong, Zheng, Jie, Li, Xingguo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.11.2014; Elsevier
• Subjects: Chemical synthesis methods; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Hydrogen generation; Hydrolysis; Materials science; Methods of nanofabrication; MgCl2; MgH2; Nanocrystalline materials; Nanoparticles; Nanoscale materials and structures: fabrication and characterization; Physics; Hydrolysis; MgH2; Nanoparticles; MgCl2; Hydrogen generation; Water; Hydrogen; Solubility; MgCl; Hydrides; Recycling; Nanostructured materials; Hydrogen production; MgH
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2014.10.002

The hydrolysis reaction of many hydrides delivers very high hydrogen capacity and is very attractive for onsite hydrogen generation. However, in real application, large excess of water is required to ensure complete hydrolysis, which causes significant capacity loss. Hydrolysis of MgH2 gives insoluble Mg(OH)2, which allows easy separation and repeated using of the excessive water. This will minimize the capacity loss caused by the excessive water. The low solubility of Mg(OH)2, however, usually causes incomplete utilization of MgH2. In this paper, we solve this paradox by using MgH2 nanoparticles together with the promotion effect of MgCl2 solution. Complete and efficient hydrogen generation can be achieved despite of the Mg(OH)2 formation. We show that by recycling the MgCl2 solution, this reaction system can approach the theoretical hydrogen capacity of 6.5wt%, providing a promising solution for onsite hydrogen generation. [Display omitted] ●MgH2 nanoparticles can be directly hydrolyzed in MgCl2 solution to give near theoretical amount of hydrogen, despite of Mg(OH)2 formation.●The MgCl2 solution can be easily recycled to give the attainable theoretical hydrogen capacity of 6.5wt%, which is very attractive for onsite hydrogen generation.