The characteristics of magnesium hydride – Activated carbon composites on different milling time

Hydrogen is regarded as a renewable and clean energy substitute to fossil fuel, for mobile applications. Storing hydrogen as a solid chemical hydride improves safety and efficiency of storage system. In this study, hydrogen was stored in the solid form of magnesium hydride (MgH2) - activated carbon (AC) composites. The purpose of this study was to determine the effect of milling time on the characteristics of MgH2−AC composites prepared by using the mechanical milling method. During composite formation, a small amount of nickel and magnesite ore as catalysts were added. The milling was conducted by using the Fritsch 6 Planetary Ball Mill from 1 h to 30 h at a milling speed of 500 rpm under hydrogen gas pressure of 0.5 MPa. In order to understand the characteristics of composites, some analysis using X-ray diffraction (XRD), Fourier Transform Infra-Red (FTIR), and Scanning Electron Microscopy (SEM) was performed. The spectra of FTIR showed that results of the FTIR spectra for each milling time variation are generally same. The longer the milling time, the absorption peaks of the C=C bonds (clusters) get weaker and move to form C-H bonds. XRD analysis showed that the content of MgH2 increased due to performing milling under a hydrogen atmosphere. Nickel was still existing in composite samples due to as catalyst did not take a reaction. SEM graphs showed that the longer the milling time, the smaller the particle size in the MgH2−AC composites. Magnesium hydride–activated carbon (MgH2−AC) composites have been successfully formed after performing mechanical milling for 30 h under a hydrogen atmosphere