Hydrogen system using novel additives to catalyze hydrogen release from the hydrolysis of alane and activated aluminum

Herein, we present a new system for the generation of hydrogen for use in portable power systems utilizing a two-step process that involves the thermal decomposition of α-AlH3 (10 wt% H2) followed by the hydrolysis of the activated aluminum (Al*) byproduct to release additional H2. This study focuses on the use of promoter additives (PA) to catalyze the hydrolysis of Al*. Our study has shown that the addition of water to a Al*:PA composite results in an instantaneous release of hydrogen at room temperature, without the use of transition metal catalysts. This secondary reaction increases the overall hydrogen content of the material even when the weight of the added water is accounted for. Additionally, a one-step process, in which water is added directly to the α-AlH3:PA composite, was also examined. Large amounts of H2 and heat are released immediately following the addition of water and could serve a means to shorten the start-up time of the fuel cell as well as assist in the thermal decomposition of α-AlH3. Our study compares the use of different PA’s and presents novel composites made of α-AlH3 and ionic hydride additives in an attempt to obtain the best performance of a hydrogen source based on α-AlH3. The composites were characterized by TGA-RGA, XRD, and SEM before and after H2 release.