High-Pressure H2 Adsorption Properties. In the previous sections, we reported that the size of the central metal ion of the pentanuclear cluster of Cu I M-MFU-4l affects the H2 adsorption below 1 bar arising from H2-Cu I coordination. For realistic demonstration of H2 storage with Cu I M-MFU-4 frameworks, it is critical to assess how differences in H2 binding energy at primary adsorption sites affect H2 adsorption profiles under practical operation conditions of H2 storage (i.e., at near-ambient temperatures and higher pressures).