Hierarchical zeolite Y as hosts for encapsulation of Fe-Schiff base complexes

A series of hierarchical zeolite Y samples with different hierarchical qualities, were used as hosts for encapsulation of metal complexes, and their host effects were investigated by XRD, N-2 adsorption/desorption, TGA, DR UV-vis, ICP, elemental analysis as well as catalytic reaction. Hierarchical zeolite Y, due to the presence of mesopores, greatly facilitated the transport of Salcn (H(2)salicyhexen) ligand in zeolite Y crystals, thus the Fe ions exchanged in the cavities of zeolite Y could fully coordinate with ligands, resulting in the prepared hybrids with less un-complexed Fe ions. FeSalcn complexes encapsulated in the hierarchical zeolite Y showed higher catalytic activities than those in the conventional microporous zeolite Y in various cycloalkane oxidation reactions. This can be ascribed to the reduced diffusion constraint imposed by the micropore of zeolite Yand the increased accessibility of encapsulated FeSalcn active sites. Furthermore, the metal complexes encapsulated in the hierarchical zeolite Y exhibited well reusability as those in the conventional zeolite Y. This work gives insights into the host effects of hierarchical zeolite Y on the preparation and catalytic performance of zeolite-encapsulated complexes. (C) 2017 Elsevier Inc. All rights reserved.