We propose to study the diffusion of molecular hydrogen (H2, HD and D2) trapped in C0 filled ice prepared at high pressure (3-5 kbar). These systems have a relevant scientific importance, both from a fundamental point of view, given the quantum nature of the molecular hydrogen motion, and from the perspective of new materials for hydrogen storage applications. Very recently we have measured the inelastic neutron spectra of H2 in filled iceon TOSCA spectrometer to investigate the quantum dynamics of the guest H2 molecule inside the filled ice. However, the field of the diffusion of H2 molecules in filled ice is a completely unexplored subject. This proposed quasi-elastic neutron scattering experiment will measure the diffusive motion of hydrogen molecules trapped inside C0 filled ice.