Study on the liquid phase-derived activation mechanism in Al-rich alloy hydrolysis reaction for hydrogen production

Bulk Al-Ga-In-Sn alloys are potential on-demand hydrogen generation materials, and Ga, In, and Sn with fascinating liquid characteristics manifest extraordinary activation capabilities in an Al–H2O reaction for hydrogen production. In the present work, the hydrogen production performances of Al-rich alloys were explored and the corresponding activation mechanism was investigated. The actual composition of the grain boundary (GB) phase in each alloy was determined by the Ga-In-Sn ternary phase diagram. A significant morphological transformation in the grain boundary particles (GBPs) was observed. Based on the surface tension of GBPs, the "Marangoni effect" was used to explain the hydrogen release rates of different alloys during hydrolysis. In addition, a liquid phase-derived activation mechanism during Al hydrolysis was proposed. The as-cast Al-Ga-In-Sn alloys were also used as energy carriers, and the power-consuming load was successfully supplied through the on-demand hydrogen supply mode, verifying the feasibility of liquid phase-activated Al-rich alloys in hydrogen energy applications.