Gas absorption is typically assessed by calculating volumetric uptakes (g of H 2 L -1 ) and gravimetric uptakes (g of H 2 g -1 ). Gravimetric uptakes are particularly important in vehicles since they measure the added weight contribution of the porous material. Volumetric uptakes, on the other hand, evaluate the energy density of hydrogen storage relative to the container size. To accurately evaluate gas adsorption, it is essential to distinguish between absolute, excess, and net adsorption. Absolute uptakes measure the total number of H 2 molecules loaded into the structure, whereas excess uptakes quantify the loading with respect to H 2 that would occupy the pore volume if there were no COF/MOF present, as