Homogenous Catalysis for Ammonia-Borane Dehydrogenation by Transition Metal-Based Complexes: A Mini Review

One of the most important sources of chemical hydrogen, Ammonia-Borane (AB), contributes greatly to the advancement of the Hydrogen Economy. The real challenge lies in addressing its sluggish kinetics and thermodynamics in terms of its dehydrogenation or the formation of molecular H₂ employing catalysis. Although it has been a decade-long enigma, the quest for an appropriate catalyst that can enable the utilization of AB in a more pragmatic way, such as its mass commercialization in society, is still ongoing. In this regard, there have been many contributions in terms of molecular catalysis towards AB dehydrogenation, encompassing both metal and metal-free compounds as efficient catalysts. Herein, we have focused on some of the transition metal-based complexes as homogeneous catalysts for AB dehydrogenation that have been known for paving the way for synthesizing, modeling, and investigating better complexes of this kind, showing improved functionality and efficacy towards the release of molecular H₂ from AB.