Moreover, it has been recently observed that the presence of oxygen functional groups also plays an important role in uptake H2. However, to the best of authorsâ knowledge, no study has been done on the stability of storage materials as they are experienced with low temperature and high pressure. Thus, the objective of this study was to investigate the structural stability of the H2 storage materials. Henceforth, a set of biomass-derived superactivated hydrochars were prepared from cellulose acetate by hydrothermal carbonization at 220 and 260 °C followed by KOH activation at 700 °C for 1 h. The volumetric H2 storage experiments were carried out in High-Pressure Volumetric Analyzer (HPVA) at 100 bar and -196 °C. A total of 9 consecutive cycles of operation were conducted for each superactivated hydrochar. The BET surface area, pore volume, pore size, and volumetric H2 uptake of the material were determined after each cycle. Additionally, surface morphology of the superactivated hydrochars were evaluated by Scanning Electron Microscope (SEM) analyzer. Analyses showed that the superactivated hydrochars underwent only a 4.5% decrease in the specific surface area and around 1.7% decrease in pore volume after 9 cycles of consecutive H2 adsorption and desorption, signifying high stability of the material for cyclic H2 storage.