We request 6 days on IRIS to study the diffusion of adsorbed H2 gas molecules within a porous aluminium-based metal-organic framework (MOF) as a function of gas loading and temperature. The proposed study will enable the nature of the diffusion of the gas molecules to be identified, which is of particular interest owing to the selective adsorption of gases exhibited by this Al-MOF. Furthermore the data obtained from the QENS study will enable the activation energy of the diffusion to be quantified and the geometry of any binding sites to be determined.