Palladium is able to dissociative absorb large quantities of hydrogen, reversibly. However, the formation and relative proportion of different phases of palladium hydride, and the width of the two-phase plateau pressure region of the H/Pd-sorption isotherms varies as a function of primary particle size down to the nanoscale. Different hydride phases have different impact on activity and selectivity in hydrogenation reactions and are related to the nanomorphology of the supported precious metal particles. These technical important properties are still not sufficiently revealed. We propose inelastic neutron scattering experiments to determine the ratio of different hydride phases of Pd in technical catalysts of realistic precious metal content and varying particle size and hydrogen loadings under in situ conditions and to compare the behaviour with a Pt catalyst with H in surface sites.