Caprolactam (CL) is a high-value chemical and precursor to nylon-6. Industrially, a harsh, liquid-acid catalyst effects the Beckmann rearrangement of C6-oxime to CL, but the risks and inefficiencies of this process make solid-acid catalysts desirable. Whilst silicoaluminophosphates (SAPOs) show potential, their micropores suffer mass transport limitations. Hierarchically-porous (HP) SAPOs contain an auxiliary mesoporous network that enhances active site accessibility, whilst retaining the selectivity of the microporous bulk. An earlier QENS study revealed the contrasting mobility of C6-oxime in HP and microporous SAPO-5, with substrate-framework interactions in HP SAPO-5 hindering motion at higher temperature. Since product desorption is a key mechanistic step that shows dependence on the nature and strength of the acid sites, we now propose to study the mobility of CL in these systems.