Effect of structural evolution of aluminum powder during ball milling on hydrogen generation in aluminum–water reaction

Effect of milling time on structure of pure Al powder and consequently on efficiency of Al-water reaction and hydrogen production is studied. Progress in milling process is studied considering changes in morphology, size, lattice imperfections and grains orientation of Al particles. Morphology of particles before and after the reaction is studied to establish a role of size and shape of particles on kinetics of the reaction. It is demonstrated that the formation of interlayer spaces within the investigated Al particles effectively increases hydrogen yield. Moreover, prolonged ball milling eliminates the interlayer spaces and decreases the rate of reaction of water with the powders.

► Ball milling changes microstructure of Al powder.
► Changes in microstructure depend on milling time.
► Hydrogen yield of Al-water reaction depends on microstructure of Al particles.
► Prolonged milling after optimum duration decreases hydrogen yield.