Ammonia Borane: An Extensively Studied, Though Not Yet Implemented, Hydrogen Carrier

Abstract

Ammonia borane H3N−BH3 (AB) was re-discovered, in the 2000s, to play an important role in the developing hydrogen economy, but it has seemingly failed; at best it has lagged behind. The present review aims at analyzing, in the context of more than 300 articles, the reasons why AB gives a sense that it has failed as an anodic fuel, a liquid-state hydrogen carrier and a solid hydrogen carrier. The key issues AB faces and the key challenges ahead it has to address (i.e., those hindering its technological deployment) have been identified and itemized. The reality is that preventable errors have been made. First, some critical issues have been underestimated and thereby understudied, whereas others have been disproportionally considered. Second, the potential of AB has been overestimated, and there has been an undoubted lack of realistic and practical vision of it. Third, the competition in the field is severe, with more promising and cheaper hydrides in front of AB. Fourth, AB has been confined to lab benches, and consequently its technological readiness level has remained low. This is discussed in detail herein.

Engineering Challenges of Solution and Slurry-Phase Chemical Hydrogen Storage Materials for Automotive Fuel Cell Applications

“…This report details our research findings related to chemical hydrogen storage not only in the narrow context related to ammonia borane and alane but also in the broader, more general context of chemical hydrogen storage materials. This manuscript complements the published works [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ] that put into perspective the challenges of hydrogen storage for automotive applications.…”

“…Of the many chemical hydrogen storage materials studied in the CHSCoE, ammonia borane and alane were down-selected for further study-primarily based on their volumetric and gravimetric hydrogen capacities and the likelihood in meeting the DOE system level targets. For a thorough review of ammonia borane and its properties, the reader is directed to the following references [ 2 , 3 , 6 ], in particular, the review by [ 4 ].…”

A Series of Primary Alkylamine Borane Adducts CxH2x+1NH2BH3: Synthesis and Properties

“…[1] It has received considerable attention over the past two decades owing to its high hydrogen density (19.5 wt% H) that has given it some potential as hydrogen storage material. [2] AB is an old molecule, [3] and it has gained new interest with the emergence of the hydrogen economy. [4] More broadly, ABAs are old molecules with new interest.…”

Catalytic Behavior of Iron-Containing Cubic Spinel in the Hydrolysis and Hydrothermolysis of Ammonia Borane

“…Ammonia borane (NH 3 BH 3 , AB) is an extensively studied hydride and dozens of review articles have already appeared discussing the results of these studies [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. The high hydrogen content of this hydride (19.6 wt%) allows it to be applied in a variety of fields: as hydrogen storage systems to generate hydrogen for the needs of hydrogen economy [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ], as a component of fuels [ 11 , 12 ], as a reducing agent in fine organic synthesis [ 13 ] and in the synthesis of metallic nanoparticles [ 14 , 15 ].…”

“…Different ways have been employed to release hydrogen from ammonia borane. Processes of its solid-state dehydrogenation from different hydride-containing materials have been described [ 5 , 7 ]. Processes of its dehydrogenation in organic solvents are also studied [ 16 ] (including with the use of catalysts [ 17 ]).…”