Effect of Magnesium Fluoride on Hydrogenation Properties of Magnesium Hydride

Energies

Pragya Jain³  Viney Dixit³  Ankur Jain²  Onkar N. Srivastava³  Jacques Huot¹ 

[1] Hydrogen Research Institute, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, CanadaInstitute for Advanced Materials Research, Hiroshima University, Higashi-Hiroshima 739-8530, Japan;Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi 221 005, India;

关键词: magnesium hydride;    magnesium fluoride;    hydrogen storage;    metal hydrides;    kinetics;   

DOI  :  10.3390/en81112330

来源: mdpi

【 摘 要 】

A cost effective catalyst is of great importance for consideration of MgH₂ as potential hydrogen storage material. In this regard, we investigated the catalytic role of alkaline metal fluoride on the hydrogen storage behavior of MgH₂. Samples were synthesized by admixing 5 mol % MgF₂ into MgH₂ powder using planetary ball mill. Hydrogenation measurements made at 335 °C showed that in comparison to only 70% absorption by pure MgH₂, catalyzed material absorbed 92% of theoretical capacity in less than 20 min and desorbed completely in almost the same time. Sorption studies done at lower temperatures revealed that complete absorption at temperature as low as 145 °C is possible. This is due to uniform distribution of MgF₂ nano particles within the MgH₂ powder. X-ray diffraction patterns also showed the presence of stable MgF₂ phase that does not decompose upon hydrogen absorption-desorption. Cyclic measurements done at 310 °C showed negligible loss in the overall storage capacity with cycling. These results reveal that the presence of the chemically inert and stable MgF₂ phase is responsible for good reversible characteristic and improved kinetics.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.