Influence of porous carbon loaded with iron particles on hydrogen storage performances of as-milled Mg-Al-Y alloy

Abstract

In this study, the [email protected] catalyst prepared by chemical blow molding carbonization was combined with mechanical milling to improve the hydrogen storage properties of Mg91Al5Y4 ternary alloy. Then, the gaseous hydrogen storage performances of as-milled Mg91Al5Y4 + [email protected] (0, 2, 5, 8 wt%) composites were tested by the Sievert apparatus. The analysis of phase was completed by using X-ray diffraction, and scanning electron microscope (SEM), transmission electron microscope (TEM) and selected area electron diffraction (SAED) were applied to realize the micromorphology observation and the determination of crystal state, respectively. In addition, the Raman spectrum of [email protected] was also measured to reflect the defect density. According to the results, the [email protected] has an effectively catalytic impact on hydrogen storage kinetics. As the [email protected] content changes from 0 to 8 wt%, the values of activation energy (Eade) are reduced from 92.23 ± 4.2 to 84.51 ± 4.5 kJ/mol and the initial dehydrogenation temperature also decreases from 533.6 to 508.7 K. The influence of [email protected] content on thermodynamics is not very obvious, but the composite Mg91Al5Y4 + 5wt.%[email protected] has the minimum absolute values of ΔHabs (Enthalpy change of hydrogen absorption) and ΔSabs (Entropy change of hydrogen absorption).