Jin, Seon-Ah Shim, Jae-Hyeok Ahn, Jae-Pyoung Cho, Young Whan Yi, Kyung-Woo 2024-01-21T00:33:37Z 2024-01-21T00:33:37Z 2021-08-31 2007-09 1359-6454 https://pubs.kist.re.kr/handle/201004/134180 Nanocrystalline MgH2 with fine and evenly dispersed Nb hydride was prepared by ball milling a mixture of MgH2 and 1 mol.% NbF5. This NbH-catalyzed MgH2 desorbed 6.3 wt.% H-2 in 15 min and absorbed more than 90% of its initial hydrogen capacity within 5 min at 573 K. Moreover, this fast sorption kinetics was maintained after 10 cycles. Based on X-ray diffraction and transmission electron microscopy/energy-dispersive spectroscopy analyses, it is suggested that NbF5 melts during high-energy ball milling and this promotes the formation of extremely fine, film-like Nb hydride preferentially along the grain boundaries of nanocrystalline MgH2 by a liquid/solid reaction. This unique nanostructured Nb hydride is believed to suppress the grain growth of MgH2 quite effectively and thus maintain its initial catalytic effect throughout repeated hydrogenation-dehydrogenation cycles. (C) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD TI-DOPED NAALH4 STORAGE MATERIALS NB2O5 MAGNESIUM OXIDES CR2O3 STATE Improvement in hydrogen sorption kinetics of MgH2 with Nb hydride catalyst Article 10.1016/j.actamat.2007.05.029 1 ACTA MATERIALIA, v.55, no.15, pp.5073 - 5079 ACTA MATERIALIA 55 15 5073 5079 scie scopus 000249896100014 2-s2.0-34547659916 Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Materials Science Metallurgy & Metallurgical Engineering Article TI-DOPED NAALH4 STORAGE MATERIALS NB2O5 MAGNESIUM OXIDES CR2O3 STATE hydrogen storage hydrides mechanical milling transmission electron microscopy catalyst