Abstract. A large probe molecule, cumene, was chosen to study diffusion and adsorption on mesopore structured ZSM-5, using a high precision intelligent gravimetric analyzer. Compared with ZSM-5, a 2–3 order of magnitude increase in the diffusion coefficient of cumene was observed on the mesopore structured ZSM-5. The increased adsorption rate and the increased adsorption heat with increas…