Artículos de revistas
Synthesis and hydrogen sorption properties of Mg2FeH6-MgH2 nanocomposite prepared by reactive milling
Registro en:
Journal Of Alloys And Compounds. Elsevier Science Sa, v. 536, n. S250, n. S254, 2012.
0925-8388
WOS:000310837500055
10.1016/j.jallcom.2011.12.103
Autor
Asselli, AAC
Leiva, DR
Jorge, AM
Ishikawa, TT
Botta, WJ
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The complex hydride Mg2FeH6 is an interesting material for hydrogen storage due to its high gravimetric hydrogen capacity as well as for having the highest known volumetric hydrogen density - 150 kg m(-3). Several papers have recently reported its synthesis from the stoichiometric precursors 2Mg-Fe or 2MgH(2)-Fe through sintering process and ball milling under argon or hydrogen atmosphere. However, regardless of processing conditions, a remaining iron always was identified by X-rays diffraction, which resulted in a lower hydrogen storage capacity. In the present paper, the Mg2FeH6-MgH2 nanocomposite was successfully synthesized through high-energy ball milling from 3Mg-Fe mixture under hydrogen atmosphere at room temperature. After the ball milling, X-rays diffraction patterns showed that the iron was kept to a minimum, which was also confirmed by simultaneous thermal analysis of differential scanning calorimetry and thermogravimetry. The gravimetric density of the ball milled 3Mg-Fe is more than 5 wt.% of hydrogen. In the case of 2Mg-Fe, processed in the same condition, the measured hydrogen capacity was 3.5 wt.%. The hydrogen sorption kinetics analyses were performed in a Sievert's apparatus in temperatures ranging from 250 degrees C to 350 degrees C. Enhanced hydrogen sorption kinetics was observed for these 3Mg-Fe milled powders in comparison with the 2Mg-Fe ones. (c) 2012 Elsevier B.V. All rights reserved. 536 1 S250 S254 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)