Cerium Ions Grafted on Functionalized Mesoporous SBA-15 Molecular Sieves: Preparation and Its Catalytic Activity on p-Cresol Oxidation

Abstract

Cerium ions were grafted onto the internal surface of organo-functionalized mesoporous SBA-15 molecular sieves by a post-synthesis method. The resultant SBA-DA-Ce materials were fully characterized by various analytical and spectroscopic techniques including powder XRD, N2 physisorption studies, SEM, FT-IR, DR-UV–Vis, TG-DTA, 29Si and 13C MAS-NMR techniques. The organo-functionality present on the surface was confirmed by the MAS-NMR and FT-IR studies, while the presence of cerium as Ce4+ ions was evident from the DR-UV–Vis studies. The catalytic activities of materials with different cerium ion content were assessed in terms of the oxidation of p-cresol under varying reaction conditions. The diamine-functionalized SBA-15 with 8 mmol of cerium ions per gram of SBA-15 (i.e., SBA-DA-Ce-8) showed the best catalytic activity, with a p-cresol conversion of ~ 87%. Cerium ions were grafted on the surface of functionalized SBA-15 by the post-synthesis method. The resultant SBA-DA-Ce showed promising activity on p-cresol oxidation with a conversion of 87%.