Revisiting Hydrogen Sorption-Desorption in Natural Rocks

Hydrogen sorption and desorption in natural rocks are increasingly referenced across subsurface energy and environmental applications, including underground hydrogen storage, natural hydrogen exploration, geological hydrogen generation, and radioactive waste containment. However, the extent to which these physical interactions influence hydrogen behavior in geological materials remains poorly understood. This review examines current experimental and theoretical studies (atomistic simulation and isotherm modeling) of hydrogen sorption and desorption in natural rocks. We evaluated reported sorption capacities and their variability across different lithologies alongside the influencing parameters and the occurrence of hysteresis. Additionally, we modeled all available data using multiple isotherm models to identify the best-fitting formulations. By synthesizing results across diverse methods and geological settings, we identify where physical sorption-desorption is likely to matter, where it is negligible, and what this means for understanding hydrogen transport and retention in the subsurface. Additionally, we provided practical implications of adsorption-desorption, identified critical data gaps, and proposed future research directions to advance the understanding of hydrogen behavior in geological formations.