In the proposed experiment ammonia borane (NH_3BH_3) will be investigated through incoherent inelastic neutron scattering on TOSCA at low temperature. Since it is well known that the enthalpy of formation of a material is lowered by increasing its surface energy, it is possible to attain hydride destabilisation by decreasing the particle size, reaching a lower hydrogen release temperature. In general particles having nano-scale size are characterised by a different thermodynamics, a faster kinetics, an increased number of defects, and modified phase transitions. However, although preparation methods are being developed to infiltrate ammonia borane into nano-porous silica (e.g. MCM-41), the physical properties of such nano-dispersed substances are still little known. We are convinced that neutron spectroscopy will clarify some crucial aspects of these new advanced materials.