Safe and efficient storage and transport of energy carriers will become a critical step towards the application of renewable energies. Application of porous materials in tank systems can vastly improve the storage capacity of gaseous energy carriers. The metal-organic framework (MOF) DUT-49 shows the largest gravimetric storage capacity of methane reported to date. In situ neutron scattering has recently been carried out on DUT-49 providing insight into the adsorption and pore-filling mechanism. Modification of the ligand in DUT-49 has lead to a family of related MOFs that show improved pore size and surface area. Herein, the adsorption mechanism of methane in these structural related materials will be investigated using combined adsorption of CD4 and coherent neutron scattering techniques. This helps analyzing the impact of pore size und surface functionalization on the adsorption mechanism of methane and thus provides a tool for designing materials with improved storage capacity.