Highly efficient hydrogen storage on porous materials under cryo-adsorption conditions

Abstract

Hydrogen has emerged as a promising clean energy carrier; however, its efficient storage remains a significant challenge. Current storage methods often fail to meet the desired volumetric and gravimetric targets owing to issues such as boil-off, hydrogen leakage, heat transfer losses, and material quality limitations. Enhancing hydrogen density in porous materials through adsorption offers a potential solution, as hydrogen interactions with materials such as metal-organic frameworks (MOFs) or carbon-based adsorbents are stronger than hydrogen-hydrogen interactions in liquid hydrogen, ammonia, or liquid organic hydrogen carriers. This study investigated the hydrogen uptake of various MOFs, including MIL-101, MOF-177, MOF-5, UiO-66(Zr), DUT-117 (Cu), and DUT-117, and activated carbon (type Maxsorb-III). Experiments were conducted under cryogenic conditions (77 K, 87 K, and 112 K) and pressures ranging from 0.1 to 5 bar. The results revealed that MOF-177 and IRMOF-10 exhibited promising hydrogen storage capacities, achieving gravimetric uptakes of 4.09 wt% and 4.55 wt%, respectively, and volumetric uptakes of 0.014 kg/L and 0.01 kg/L at 5 bar and 77 K. Using experimentally confirmed isotherms, kinetics, and thermodynamic frameworks of MOFs–H2 systems, this study analyzed the dynamic behavior of hydrogen storage across pressures (1–5 bar) and temperatures (77 K–298 K). These findings demonstrate that the hydrogen densities in porous materials under cryogenic conditions are 10 times higher than those in the gaseous phase. These insights are critical for designing and optimizing adsorption-based hydrogen storage systems, paving the way for more efficient and scalable hydrogen energy solutions.