Microporous layered silicate AMH-3 has a 3D ordered porous structure that is therefore very promising as a permselective barrier. However, for use as permselective barrier, the removal of the Na + and Sr 2+ cations located in the intralayer and interlayer spaces and the delamination of an individual layer must be carried out. We successfully obtained delaminated AMH-3 by acid-hydrothermal treatment without the use of swelling agent. The delamination conditions have been optimized to find the best morphology for use as permselective barrier. The pristine AMH-3 and the delaminated AMH-3 were characterized with FE-SEM, N 2 adsorption, ICP-AES, 29 Si MAS NMR, FT-IR, and WXRD analyses. These results show that the delaminated AMH-3 has a more ordered pore structure than the pristine AMH-3 and that it retains framework crystallinity in the AMH-3 layers. The methanol permeability, proton conductivity and liquid uptake of Nafion membrane coated with a delaminated AMH-3/Nafion nanocomposite layer were examined. This type of membrane was found to exhibit a lower methanol permeability than neat Nafion and to maintain a high proton conductivity. We can thus conclude that delaminated AMH-3 is potentially good permselective barrier for the reduction of methanol crossover in DMFCs.