Synthesis, Characterization and Catalytic Studies of Mn-MCM-48

Abstract

High quality MCM-48 was hydrothermally synthesized using different silica sources-fumed silica and tetraethylorthosilicate. A comparison of the XRD pattern of the pre- and post treated samples clearly shows the definite well ordered structural pattern in the post treated MCM-48 samples. This is also confirmed from the SEM and TEM images of the sample. The Mn-MCM-48 was also synthesized by ion-exchange and calcinations of the previously prepared MCM-48 with permanganate solution. The EPR analysis shows that the manganese is reduced from Mn⁷⁺ to Mn²⁺ during calcinations and may be in the extra framework octahedral sites of the framework structure. The surface area of the mesoporous material was determined from N₂ adsorption isotherm plot. An epoxidation of styrene study with Mn-MCM-48 shows 87 % conversion in 5 h.