Abstract
Ammonia alane AlH3NH3 (AA) exhibits a high gravimetric hydrogen storage capacity, with 12.86 wt% H, positioning it as a potential solid hydrogen carrier. It has nevertheless received limited attention, with only few computational studies exploring its capabilities, and it has been overshadowed by its boron analog ammonia borane BH3NH3 (AB). The lower focus on AA can be attributed to its instability at temperatures above −80 °C. However, the dehydrogenation of AA has been predicted to be endothermic, and this is an attractive feature for achieving reversible hydrogen storage. AA holds thus potential as a hydrogen carrier even though its implementation is likely to pose challenges. This is the guiding principle of this article. It aims to (i) comprehensively review existing work on AA, (ii) compare the current understanding of the potential of AA as a hydrogen carrier to that of AB, (iii) address the limitations and challenges that must be overcome for effective use of AA as a solid hydrogen carrier, and (iv) discuss perspectives.