Activation of bulk aluminum and its application in a hydrogen generator

Aluminum is a highly energy dense material that can enable simple and safe hydrogen generation when reacted with water. We present a method for activating cold-worked non-recrystallized bulk aluminum objects (aluminum bbs) by surface treatment with a heated gallium-indium (Ga-In) eutectic melt. Afterwards, the activated aluminum can be reacted with water to generate hydrogen gas, heat and aluminum oxihydroxide. The elevated temperature of the eutectic melt during treatment allows the Ga-In to efficiently penetrate the aluminums’ plastically strained grain boundaries, causing liquid metal embrittlement and activation of the aluminum. This unique method of activation produces a highly reactive aluminum fuel using only 3–4 wt% Ga-In eutectic which can then be reacted with water in a controllable manner.The surface treatment time, temperature of the melt, and composition of the melt were varied and the effects on hydrogen yields were compared. It was found that the addition of temperature, sufficient time in the melt, and gallium/indium ratio were key to activation efficiency. The activated aluminum was then tested in a small-scale hydrogen generator, which steadily and controllably produced nearly 94% of expected hydrogen yield using less than 4% gallium-indium eutectic for activation.