Moderate Temperature Dense Phase Hydrogen Storage Materials within the US Department of Energy (DOE) H₂ Storage Program: Trends toward Future Development

Abstract: Hydrogen has many positive attributes that make it a viable choice to augment the current portfolio of combustion-based fuels, especially when considering reducing pollution and greenhouse gas (GHG) emissions. However, conventional methods of storing H₂ via high-pressure or liquid H₂ do not provide long-term economic solutions for many applications, especially emerging applications such as man-portable or stationary power. Hydrogen storage in materials has the potential to meet the performance and cost demands, however, further developments are needed to address the thermodynamics and kinetics of H₂ uptake and release. Therefore, the US Department of Energy (DOE) initiated three Centers of Excellence focused on developing H₂ storage materials that could meet the stringent performance requirements for on-board vehicular applications. In this review, we have summarized the developments that occurred as a result of the efforts of the Metal Hydride and Chemical Hydrogen Storage Centers of Excellence on materials that bind hydrogen through ionic and covalent linkages and thus could provide moderate temperature, dense phase H₂ storage options for a wide range of emerging Proton Exchange Membrane Fuel Cell (PEM FC) applications.