We propose to perform QENS experiments on the OSIRIS spectrometer to study hydrogen diffusion in a carbon aerogel which has been synthesized at the University of Budapest and exhibits a very high specific surface area. OSIRIS offers a particularly large Q-range, which will allow us to make precise conclusions about the jump diffusion of the molecules, e.g. the jump distance and rate. We also expect to observe a QENS broadening that corresponds to a KWW type stretched exponential decay of the intermediate scattering function. The high energy resolution that OSIRIS provides even in the high-Q setting will allow us to extract the expected stretching parameter as a function of Q and thus relate it to the fractal dimension of the carbon matrix. We plan to measure at 6 temperatures from 14K to 60K and at two surface coverages, 0.1ML and 0.5ML of adsorbed hydrogen.