The physisorptive capability of graphite-based nanomaterials for hydrogen is strongly dependent on their surface areas and nanomorphologies. We have made electrospun graphite nanofibres (GNF) as promising nanostructures and have doped them with potassium to improve H2 storage capacity by opening the graphite to H2, increasing binding through charge transfer and improving sorption kinetics. In recent work on the hydrogenated graphite intercalate KC24(H2)x, we proposed quantum mechanical limitations to explain the known H2 uptake. By analogy we intend to study the para-H2 binding and diffusion in a K-doped GNF sample as a function of H2 loading. Low energy INS (0-15 meV) has proven itself a matchless probe of H2 sites close to K ions, making IRIS the natural choice of instrument, and we also propose a complementary TOSCA experiment to study H2 librations in the 50 meV region.