The route to a feasible hydrogen-storage material: MOFs versus ammonia borane

The replacement of fossil fuels is one of the greatest challenges that chemistry and material sciences will have to face in the near future. While hydrogen seems to be the most likely candidate for this, a material able to store the hydrogen itself is sorely needed. Intense research in the past decade has narrowed down the field of possible concepts to two materials: ammonia borane with chemically bound hydrogen atoms and metal-organic frameworks with physisorbed hydrogen molecules. Herein we want to give an overview of the strengths and weaknesses of each concept, discuss the challenges that need to be overcome, and try to compare the future capabilities of these two materials.