Diffusion pathway for propylene adsorption in AlPO-14 characterized by molecular modeling and in situ synchrotron powder diffraction

Abstract The detailed structures of AlPO-14 in N 2 , propane and propylene were determined under various pressures and temperatures using an in situ reactor and synchrotron radiation. N 2 and propane did not significantly modify the AlPO-14 structure, whereas complex changes were observed on adsorption of propylene. For samples with high propylene loading, the locations of the propylene molecules in the pores were found by difference Fourier analyses and refined by Rietveld methods. Theoretical modeling using the determined structures showed that is the most likely diffusion path for propylene in AlPO-14. The adsorption of propylene appeared to modify the pore openings and retard desorption.