Metal hydride materials for solid hydrogen storage: a review

Increased attention is being focused on metal-organic frameworks as candidates for hydrogen storage materials. This is a result of their many favorable attributes, such as high porosity, reproducible and facile syntheses, amenability to scale-up, and chemical modification for targeting desired properties. A discussion of several strategies aimed at improving hydrogen uptake in these materials is presented. These strategies include the optimization of pore size and adsorption energy by linker modification, impregnation, catenation, and the inclusion of open metal sites and lighter metals.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/anie.200462786

Strategies for hydrogen storage in metal--organic frameworks.

Widespread adoption of hydrogen as a vehicular fuel depends critically upon the ability to store hydrogen on-board at high volumetric and gravimetric densities, as well as on the ability to extract/insert it at sufficiently rapid rates As current storage methods based on physical means—high-pressure gas or (cryogenic) liquefaction—are unlikely to satisfy targets for performance and cost, a global research effort focusing on the development of chemical means for storing hydrogen in condensed phases has recently emerged At present, no known material exhibits a combination of properties that would enable high-volume automotive applications Thus new materials with improved performance, or new approaches to the synthesis and/or processing of existing materials, are highly desirable In this critical review we provide a practical introduction to the field of hydrogen storage materials research, with an emphasis on (i) the properties necessary for a viable storage material, (ii) the computational and experimental techniques commonly employed in determining these attributes, and (iii) the classes of materials being pursued as candidate storage compounds Starting from the general requirements of a fuel cell vehicle, we summarize how these requirements translate into desired characteristics for the hydrogen storage material Key amongst these are: (a) high gravimetric and volumetric hydrogen density, (b) thermodynamics that allow for reversible hydrogen uptake/release under near-ambient conditions, and (c) fast reaction kinetics To further illustrate these attributes, the four major classes of candidate storage materials—conventional metal hydrides, chemical hydrides, complex hydrides, and sorbent systems—are introduced and their respective performance and prospects for improvement in each of these areas is discussed Finally, we review the most valuable experimental and computational techniques for determining these attributes, highlighting how an approach that couples computational modeling with experiments can significantly accelerate the discovery of novel storage materials (155 references)

http://www-personal.umich.edu/~djsiege/Energy_Storage_Lab/Publications_files/CSR_H2_storage.pdf

High capacity hydrogen storage materials: attributes for automotive applications and techniques for materials discovery

The U.S. Department of Energy's National Hydrogen Storage Project: Progress towards meeting hydrogen-powered vehicle requirements

Ammonia–borane, H3NBH3, is an intriguing molecule for chemical hydrogen storage applications. With both protic N–H and hydridic B–H bonds, three H atoms per main group element, and a low molecular weight, H3NBH3 has the potential to meet the stringent gravimetric and volumetric hydrogen storage capacity targets needed for transportation applications. Furthermore, devising an energy-efficient chemical process to regenerate H3NBH3 from dehydrogenated BNHx material is an important step towards realization of a sustainable transportation fuel. In this perspective we discuss current progress in catalysis research to control the rate and extent of hydrogen release and preliminary efforts at regeneration of H3NBH3.

Ammonia-borane: the hydrogen source par excellence?

A panoramic overview of hydrogen storage alloys from a gas reaction point of view

Effect of Ti-catalyst content on the reversible hydrogen storage properties of the sodium alanates

The potential for using aluminum hydride, AlH3, for vehicular hydrogen storage is explored. It is shown that particle-size control and doping of AlH3 with small levels of alkali-metal hydrides (e.g. LiH) results in accelerated desorption rates. For AlH3–20 mol % LiH, 100 °C desorption kinetics are nearly high enough to supply vehicles. It is highly likely that 2010 gravimetric and volumetric vehicular system targets (6 wt % H2 and 0.045 kg/L) can be met with onboard AlH3. However, a new, low-cost method of off-board regeneration of spent Al back to AlH3 is needed.

G. Sandrock

Papers

A panoramic overview of hydrogen storage alloys from a gas reaction point of view

Effect of Ti-catalyst content on the reversible hydrogen storage properties of the sodium alanates

Accelerated thermal decomposition of AlH 3 for hydrogen-fueled vehicles

Engineering considerations in the use of catalyzed sodium alanates for hydrogen storage

Alkali metal hydride doping of α-AlH3 for enhanced H2 desorption kinetics