No abstract

This paper examines the effect of metal loading (Zr-, V-, Ti-, and K-compounds) on the hydrogen storage property of mechanically milled graphite. The hydrogen adsorption took place at room temperature and 11 MPa measured by thermal volumetric analysis. The results showed that the graphite loaded with ZrCl4provided a maximum hydrogen storage capacity of 0.6 wt%. Moreover, a milling time of 2 h seems to be the best, offering the highest hydrogen adsorption capacity due to the high specific surface area and the appropriate pore diameter created after the milling. In addition, it was found that the transition metals (ZrCl4and VCl3) could stabilize the graphite structure and enlarge the gap between the grapheme layers to be suitable trapping sites for hydrogen adsorption. On the other hand, the K2CO3and TiO2loaded graphite did not show any improvement for hydrogen adsorption.