Comparative hydrogen storage capability of similar adsorption capacity adsorbents: MOF-5 vs activated carbons

摘要

The present work, dealing with high pressure hydrogen storage, at 77K up to 4MPa, on two types of solid adsorbents (activated carbon and MOF) and with the analysis of important parameters of the adsorbents affecting hydrogen storage (e.g. micropore volume and apparent surface area), is focussed on the way we express the hydrogen adsorption capacity: hydrogen adsorbed per unit of adsorbent weight (gravimetric basis) or per unit of adsorbent volume (volumetric basis). Considering the application under study (hydrogen storage) we conclude the need of reporting the results in a volumetric basis and hence we point out the need of measuring the density of the adsorbents giving precise details about how the density measurements have been made to avoid wrong conclusions when comparing different types of adsorbents. The results obtained with three similar adsorption capacity adsorbents (two activated carbons (AC) and one MOF) show, contrarily to what has been claimed, that MOF does not perform better than the activated carbon.