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Transformation of Metallic Ti to TiH2 Phase in the Ti/MgH2 Composite and Its Influence on the Hydrogen Storage Behavior of MgH2 |
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| Authors: | Dr. D. Pukazhselvan Karakkadparambil Sankaran Sandhya Devaraj Ramasamy Aliaksandr Shaula Duncan Paul Fagg |
| Affiliation: | 1. Nanoengineering Research Group, TEMA, Department of Mechanical Engineering, University of Aveiro, 3810-193 Aveiro, Portugal;2. Sree Chitra Thirunal College of Engineering, Department of Applied Science, H 66, CTO Colony Pappanamcode, Thiruvananthapuram, Kerala, 695018 India;3. UIDM, ESTG, Polytechnic Institute of Viana do Castelo, 4900 Viana do Castelo, Portugal |
| Abstract: | The current work explores the in-situ formation of TiH2 additive in a Ti/MgH2 nanocomposite system. Mild mechanical milling leaves Ti chemically unchanged, while formation of stable TiH2–x occurs upon strong mechanical milling. TiH2–x further transforms to TiH2 upon recycling the powder (dehydrogenation and subsequent hydrogenation) and lowers the activation energy of MgH2 to 89.4 kJ (mol H2)−1 [Ea of as-received MgH2 is 153 kJ (mol H2)−1]. This work also reiterates that metallic Ti additive mixed MgH2 requires strong mechanical milling for better H2 ab/de-sorption performance. The current observations support the view that lattice strain may be an important factor in the catalysis of additives incorporated MgH2 hydrogen storage systems. |
| Keywords: | Additives catalytic mechanism hydrogen storage reaction kinetics surface reaction |