Combined with computational modeling, in situ inelastic neutron scattering (INS) will be employed to reveal the nature of the interactions between stored ammonia and the host structure of UiO-67 metal-organic frameworks (MOFs) as a function of increased ammonia loading. Results will be used to interpret the stepped ammonia sorption isotherms of these materials, which may open a new perspective of the structure-adsorption relationship in MOF materials. Findings will also enable our rational design of Zr-based MOFs for efficient catalytic ammonia decomposition to produce hydrogen for fuel cell applications.