This proposal builds on the success of our last INS experiment (RB1210041), which used TOSCA's new low energy capabilities to access and track the elastic line as well as the shape of the recoil features, showing the H2 adsorbed into our standard microporous carbon test material had spectral features consistent with a solid-like density H2 at temperatures far above the critical point of H2. We will collect INS spectra during in-situ high-pressure H2 dosing on MIL-101, a high uptake metal-organic framework with a tri-modal pore size distribution, at 77 K. The results will be compared to the results of molecular GCMC modelling.The possibility of using H/D scattering contrast will also allow quantification of the mobility of the adsorbed phase as well as the free gas contribution, allowing direct measurement and definition of the absolute adsorbed phase.