High-yield direct synthesis of Mg 2FeH 6 from the elements by reactive milling

• Autor(a) principal: Leiva, Daniel Rodrigo
• Data de Publicação: 2011
• Outros Autores: De Souza Villela, André Castro, De Oliveira Paiva-Santos, Carlos [UNESP], Fruchart, Daniel, Miraglia, Salvatore, Ishikawa, Tomaz Toshimi, Botta, Walter José
• Tipo de documento: Artigo de conferência
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.4028/www.scientific.net/SSP.170.259; http://hdl.handle.net/11449/72439
• topic: Hydrogen storage; Mg 2FeH 6 synthesis; Nanocomposites; Reactive milling; Ball-to-powder weight ratio; Complex hydrides; Direct synthesis; Equilibrium conditions; Hydrogen pressures; Intermetallic phase; Low costs; Magnesium complexes; Milling time; Processing parameters; Volumetric density; Hydrogen; Magnesium; Milling (machining); Transition metals; Ball milling

Magnesium complex hydrides as Mg 2FeH 6 are interesting phases for hydrogen storage in the solid state, mainly due to its high gravimetric and volumetric densities of H2. However, the synthesis of this hydride is not trivial because the intermetallic phase Mg2Fe does not exist and Mg and Fe are virtually immiscible under equilibrium conditions. In this study, we have systematically studied the influence of the most important processing parameters in reactive milling under hydrogen (RM) for Mg 2FeH 6 synthesis: milling time, ball-to-powder weight ratio (BPR), hydrogen pressure and type of mill. Low cost 2Mg-Fe mixtures were used as raw materials. An important control of the Mg 2FeH 6 direct synthesis by RM was attained. In optimized combinations of the processing parameters, very high proportions of the complex hydride could be obtained. © (2011) Trans Tech Publications.