The goal of this project was to develop new nanostructured sorbent materials, using the hydrogen spillover mechanism that could meet the DOE 2010 system targets for on--board vehicle hydrogen storage. Hydrogen spillover may be broadly defined as the transport (i.e., via surface diffusion) of dissociated hydrogen adsorbed or formed on a first surface onto another surface. The first surface is typically a metal (that dissociates H2) and the second surface is typically the support on which the metal is doped. Hydrogen spillover is a well documented phenomenon in the catalysis literature, and has been known in the catalysis community for over four decades, although it is still not well understood. 1, 2 Much evidence has been shown in the literature on its roles played in catalytic reactions. Very little has been studied on hydrogen storage by spillover at ambient temperature. However, it is also known to occur at such temperature, e.g., direct evidence has been shown for spillover on commercial fuel--cell, highly dispersed Pt/C, Ru/C and PtRu/C catalysts by inelastic neutron scattering. 3 To exploit spillover for storage, among the key questions are whether spillover is reversible at ambient temperature and if the adsorption (refill) and desorption rates at ambient temperature are fast enough for automotive applications.In this project, we explored new sorbents by using a transition metal (e.g., Pt, Ru, Pd and Ni) as the H2 dissociation source and sorbents as the hydrogen receptor. The receptors included superactivated carbons (AX--21 and Maxsorb), metal organic frameworks (MOFs)