Screening Study of the Effects of Impurity Gases on Hydrogen Storage in Metal-Organic Frameworks

Metal-organic frameworks (MOFs) are perhaps one of the promising candidates for H2 storage in a fuel cell vehicle. However, impurity gases, such as H2O, CO2, CH4, O2, and N2 existing in the process of H2 production, have a detrimental impact on H2 storage. In the present work, the process of H2 with and without impurity gases (i.e., H2O, CO2, CH4, O2, and N2) adsorption in 95 MOFs is screened by molecular simulation. The effect of a low concentration of impurity gases on the H2 delivery capacity is studied. The results show that the effect of impurity gases on the H2 delivery capacity of 95 MOFs ranks as H2O>CO2>CH4>O2=N2. DIDDOK is demonstrated to exhibit the best gravimetric delivery capacity of H2, and ANUGIA exhibits the best volumetric delivery capacity of H2. These results show that one should consider impurity gas effects during screening the best adsorbent for H2 storage in fuel cell vehicles.