New synthetic route for the incorporation of manganese species into the pores of MCM-48

The present work describes a new way to synthesize manganese species within the channels of mesoporous MCM-48 silica using permanganate as manganese precursor agent. For the first time permanganate ions were incorporated within the as-synthesized mesoporous host by ion-exchange process. The resulting materials were characterized by XRD, N-2 sorption, transmission electron microscopy, EPR, XPS, Raman, and elemental analysis methods. The structure of the MCM-48 host material is maintained as indicated by XRD and HRTEM, and the surface areas of the MnMCM-48 materials are in the 670-930 m(2)/g range compared to 1090 m2/g for the host. The characterization results also indicate the presence of manganese species inside the silica pores, as well as a good dispersion of the manganese particles within the pores of the host material. Controlled manganese loading was possible to a maximum of 13 wt %. No bulk manganese was detected outside the MCM-48 mesoporous silica particles.