Hydrolysis of ammonia borane as a hydrogen source: fundamental issues and potential solutions towards implementation

Abstract

In today’s era of energy crisis and global warming, hydrogen has been projected as a sustainable alternative to depleting CO₂-emitting fossil fuels. However, its deployment as an energy source is impeded by many issues, one of the most important being storage. Chemical hydrogen storage materials, in particular B—N compounds such as ammonia borane, with a potential storage capacity of 19.6 wt % H₂ and 0.145 kgJ₂ L⁻¹, have been intensively studied from the standpoint of addressing the storage issues. Ammonia borane undergoes dehydrogenation through hydrolysis at room temperature in the presence of a catalyst, but its practical implementation is hindered by several problems affecting all of the chemical compounds in the reaction scheme, including ammonia borane, water, borate byproducts, and hydrogen. In this Minireview, we exhaustively survey the state of the art, discuss the fundamental problems, and, where applicable, propose solutions with the prospect of technological applications.