Hydrogen Generation via Catalytic Ammonia Borane Hydrolysis: A Patent Overview

Hydrogen is one of the clean energies that will play an important role in energy selection for the coming low-carbon society. Ammonia borane (NH3BH3, abbreviated hereafter as AB) is considered as a promising hydrogen storage material due to its high hydrogen content (19.6 wt%), stability under ambient conditions (white powder), and favorable properties in dehydrogenation. AB can release hydrogen via pyrolysis, alcoholysis, hydrolysis, etc. Among these, AB hydrolysis is a safe and effective route, as it proceeds under mild conditions in the presence of an appropriate catalyst without the need for additional heat sources. For practical application, it is important to develop an efficient catalyst that further improves the hydrolytic dehydrogenation properties of AB. Many papers and reviews have been published, suggesting the research is at an advanced stage. On the other hand, since new technologies are often patented before they are put into practical use, the status of patent publication is of significant interest. This mini-review analyzes patent applications published up to 2023 on hydrogen generation via catalytic AB hydrolysis. The patent search yielded 99 patent publications, which were examined not only by country and research institution but also by two representative types of catalysts derived from noble metal (abbreviated hereafter as NM) and non-NM. Based on the analysis, future research and development was discussed.